Fantastic Silky Gold: 2011

Senin, 26 Desember 2011

Erie Computer Company and Costcentral.com.

Canon - 4286B008AACanon imageCLASS LBP6000 - Printer - B/W - laser - 2400 dpi x 600 dpi - up to 19 ppm - capacity: 150 sheets - USB Mfg Part #: 4286B008AA $45.00 Buy Now HP - FB343AA#AC3HP TouchPad Case - Case for web tablet - for TouchPad Mfg Part #: FB343AA#AC3 $18.99 Buy Now Microsoft - T6D-00123Microsoft Office Professional Academic 2010 - Complete package - 1 PC - EDU - DVD - Win - English - United States - 32/64-bit Mfg Part #: T6D-00123 $86.23 Buy Now Microsoft - JRF-00001Microsoft TechNet Subscription Standard 2010 - Subscription license ( 1 year ) - 1 user - Win - English Mfg Part #: JRF-00001 $168.63 Buy Now Wacom - CTH670Wacom Bamboo Create - Digitizer, stylus - 9 x 5 in - electromagnetic - wired - USB Mfg Part #: CTH670 $166.06 Buy Now Lenovo - 41717FULenovo ThinkPad T420s 4171 - Core i7 2640M / 2.8 GHz - vPro - RAM 4 GB - HDD 160 GB SSD - DVD-Writer - NVS 4200M / HD Graphics 3000 - 3G Upgradable - Gigabit Ethernet - WLAN : 802.11 a/b/g/n, Bluetooth 3.0 - TPM - fingerprint reader - 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Costcentral.com is not responsible for typographical or photographical errors. Prices and specifications are subject to change without notice. Verified by Visa McAfee SECURE sites help keep you safe from identity theft, credit card fraud, spyware, spam, viruses and online scams Google Checkout Acceptance Mark Click to Verify - This site has chosen a VeriSign SSL Certificate to improve Web site security BBBOnLine Reliability Seal MasterCard SecureCode

Senin, 19 Desember 2011

5 Essential Guides on Posting Resume Online

H Skip to content Skip to main navigation Skip to 1st column Skip to 2nd column 5 Essential Guides on Posting Resume Online PDF Print E-mail User Rating: / 0 PoorBest Careers Employment Written by lino claudio Friday, 18 January 2008 00:58 to your way. Here are the 5 essential guides on posting resume online. 1. Resume Posting is a service where job seekers post their resumes to an online job search site for employers and recruiters to find. Employers or recruiters usually find you within the resume database, of an online job search site, using key words will put up the chances for most of the applicants to find easily by the employers and finally call for a job interview. However it depends on how you select appropriate keywords for your resume and remember that this service is usually offered free for job seekers. 2. Use a word processing programs such as MS Word that have basic and advanced tools to create and format your resume. You should also create an electronic friendly version of your resume by making a back up data in MS Word based resume to a Notepad. The former application will convert your resume into ASCII text which allows your resume to be read in email format. In order to ensure that the employers can find you, your resume should contain key words that is strongly related to the position that you are applying for. 3. The primary advantage of posting your resume online is that your resume will be available to a wide array of employers and recruiters in the shortest period of time. Presumably, you will gain access to a large number of job opportunities compared to the access you will have by viewing employment advertisements, company web sites, employment web sites or the newspapers. And it is easy, fast and rather practical. 4. The biggest advantage of online resume posting is also its biggest disadvantage because it makes your resume along with your personal information available to the public. It can result to numerous phone calls from headhunters, agencies, employment consultants or even telemarketers. Its a reminder for everyone to not give too much personal information in their resume online, be careful and wisely before putting any remarks that might become a problem. 5. You should choose your resume bank wisely. Some offers their service for free while others have a monthly free. Aside from the service cost, you should consider the scope of the service that you choose. Some resume bank offers national exposures while others might be run by professional association or network of businesses. Weigh in the pro’s and con’s before finally submitting your resume online to avoid regrets at the end. Posting resume online through resume banks or job search sites will certainly help you form a wide network in your career search. The key reminders are: prepare a strong resume, search for the best resume bank based on your needs, post your electronic resume and prepare yourself for the great career opportunities that awaits you. Build a confident before and after meeting with an employer and be sure to take all the charges when it comes to present yourself professionally and elegantly. Ozfreeonline recommends Job Search at OzFreeOnline for your Career Opportunity. Ozfreeonline is the author of job posting site. < Prev Next > Last Updated on Friday, 18 January 2008 00:58 Our valuable member lino claudio has been with us since Sunday, 18 April 2010. Show Other Articles Of This Author Confessions of a Fresh Graduate (04 February 2008) 20 Tips to Dress for Success (23 January 2008) Copyright © 2011 GoArticles. All Rights Reserved. SYSOX Web Hosting.5 Essential Guides on Posting Resume Online

Kamis, 27 Oktober 2011

Creativity Software

Roshan selects Creativity Software for advanced vehicle and asset tracking Roshan implements location-based service solution in Afghanistan to increase safety and security Challenge Roshan, the leading GSM operator in Afghanistan, has witnessed extraordinary growth in the short time since it was awarded the country's second national GSM license in 2003. Roshan, which means "light" in the local Dari and Pashto languages, is owned by a consortium of investors, including the Aga Khan Fund for Economic Development, Monaco Telecom International (part of Cable and Wireless) and TeliaSonera. Download the case study in full. Roshan continues to innovate and develop a portfolio of services that allows it to address multiple market segments. In particular, Roshan has delivered mobile communications services to many remote and rural areas, and recognised the potential for leveraging this reach with the evolution of special services targeted at some of its larger clients, such as Non-Governmental Organisations (NGOs) and logistics companies active in supporting a variety of initiatives. For such services to be attractive and successful, it was for Roshan vital to demonstrate clear financial benefits to existing and potential customers. In addition, the new services had to blend capabilities that added genuine value to existing communications models and extend them in novel directions. Afghanistan is a large country and provides some spectacular, yet challenging geography. One of the biggest problems in such an environment is the safe and timely distribution of goods to all required locations. Developing, but still limited, internal infrastructure means that existing distribution costs are high. So Roshan needed to find a way to provide a service that reduces these overheads for its customers while leveraging its communications network. Central to this challenge was the ability to track assets in real-time. For example, security issues meant that conventional, network-based solutions were not appropriate. While network-based solutions, such as those derived from the combination of a Gateway Mobile Location Centre (GMLC) and Serving Mobile Location Centre (SMLC), provide extremely granular positioning in dense, urban areas, the large amount of remote terrain in Afghanistan limits their accuracy. Therefore, Roshan needed to provide a solution that could both guarantee accuracy, and integrate seamlessly into their communication infrastructure, irrespective of distance from areas of higher coverage and dense population. A further challenge was the lack of appropriate mapping data available for determining the exact position of assets. Roshan needed the best source of digital map and satellite information available in order to provide organisations with reliable data to track and protect their assets. In addition, although Roshan's network supported 2.5G data services based on General Packet Radio Service (GPRS), these data rates could not be guaranteed across different regions. Therefore, any solution requiring communications with centralised control and distribution points had to allow for a contingency 'best effort' approach, where necessary, to ensure timely delivery of updates and information from assets being tracked in the field. Solution The solution for Roshan was to launch the TrackCare GPS Vehicle Tracking Solution. TrackCare, enabled by GPS positioning technology, allows customers to track the movement of assets throughout Afghanistan. In order to add value to customers and hence increase demand, Roshan decided to make the service interactive. TrackCare also provides remote management, control and monitoring services for the assets in question, in addition to real-time location updates and reporting. After an extensive vendor-selection process, Roshan chose location-based services specialist, Creativity Software, as its partner. Creativity Software's TransportWise application sits at the core of the TrackCare solution and, while its advanced capabilities are compelling, that was just one of the reasons why Roshan chose the UK-based company. For example, Creativity Software's expertise in the broad field of location-based services was another major factor, allowing it to operate as a specialist 'one-stop shop', and to provide the complex integration of the different elements of the service. A further key differentiator was Creativity Software's partnership model, providing vital training and support services for service launch. Its full lifecycle approach ensured that Creativity Software was an integral part of Roshan's project management and fulfilment team. The solution itself consists of a tracking device, which is mounted inside the vehicles or assets being tracked. The device integrates GPS functionality to provide advanced and accurate tracking of assets throughout Afghanistan. As well as providing location information, the device can be used to control a number of features of the vehicles. For example, the vehicle can be locked remotely, or the status of the engine, doors and locks can be provided to the control centre. By knowing the engine's status and the speed of the vehicle, operators can ensure that it follows the prescribed route and maintains an efficient speed – excessive speed or deviation from a planned route can lead to increased fuel consumption, so awareness of vehicle movement and location can generate cost savings and efficiencies. With many organisations having large fleets of vehicles, the cumulative impact of such savings can be significant. Creativity Software's TransportWise application provides the underlying intelligence behind the solution. Using the GPS positioning information, the location, speed and direction of vehicles and assets can be viewed and managed by users. The solution can provide a view of all resources, or a focus on individual items. In addition, by relating positioning information to the landscape of Afghanistan via mapping resources, advanced geo-fencing rules can be constructed. For example, when an asset moves outside a defined area, the in-vehicle devices generate alarms that are collected and processed by the TransportWise applications. These alarms are typically generated via Short Message Service (SMS), although GPRS data can be used when it is available. This means that control personnel know instantly if vehicle behaviour deviates from the normal rules of operation. The real-time alerting and remote control capabilities of the in-vehicle device provide further reassurance and confidence that appropriate action can be taken in response to the unexpected event. TransportWise also offers open interfaces to external mapping software and solutions, which allowed Roshan and Creativity Software to carefully select the best resources for deployment in Afghanistan. With no single solution available, the open interface allowed several mapping resources to be used in combination to produce an optimum result. Points of Interest were added to enhance the user experience and to ensure the best context for the positioning service. Finally, the rich set of features enabled by the solution also required users to act responsibly – vehicles cannot simply be disabled remotely; protocols were required for responses to unexpected events. Creativity Software played an important role in training Roshan in the safe and consistent use of the features and capabilities, and helping it to develop best practice procedures and metrics. This joint learning experience proved invaluable in preparing the solution for service launch and in ensuring its success. Results Thanks to Creativity Software's innovation and committed partnership, Roshan was able to launch its new TrackCare service in a timely and efficient manner. Creativity Software's TransportWise application could be white-labelled and branded by Roshan, allowing its brand to be developed and enhanced through the launch of the innovative service. TrackCare offers existing and potential customers immediate financial benefits, primarily through more efficient resource management. For example, fuel costs are a significant overhead for all companies involved in logistics. With TrackCare, different target segments can achieve real and dramatic cost savings through efficient speed management. For NGOs, this can result in cost savings of up to $145,000 per year in fuel alone. TrackCare also has the incidental benefit of reducing the costs of accidents by more than 60% and the occurrence of such events by 50%. Studies also suggest that the solution can increase the amount of service calls completed each day by as much as 23%, ensuring that tasks are completed quicker and with greater efficiency. With clear historical and real-time information available, agencies and fleet owners obtain better information, leading to enhanced planning and co-ordination of resources, and helping them evolve more effective strategies. Over time, this can also generate significant efficiencies and cost savings. Furthermore, the in-vehicle device can be installed in a discrete or hidden location, ensuring that it is invisible to outsiders. In the event that a vehicle is misappropriated, controllers can quickly spot any deviation from the expected route and take steps to stop the vehicle remotely, through cutting off the fuel supply or disabling the ignition, pending recovery through the appropriate agencies. The insurance factor offered by this technology provides additional reassurance to potential customers. Roshan was able to present a well-supported and validated business case to its customers, channelled through a clear proposition that encompassed a number of key benefits: * Reduced costs by stategically managing routes and driver efficiency; * Monitoring location of vehicles 24 hours a day, seven days a week; * Increased asset protection; * Increased employee security - with geo-fences that alert you when a vehicle leaves a safe zone; * Customised reports to track organisation's fleet management; * Faster response in emergency/security situations with real-time web interface; * Recovery of lost and stolen assets. In partnership with Creativity Software, Roshan can demonstrate the benefits of the solution to its customers and enhance its reputation and brand through the launch of a valuable service which it was uniquely equipped to offer. Creativity Software's unrivalled expertise in location-based services and its understanding of the entire value chain enabled it to provide a full service to Roshan. The TrackCare project called for clear understanding, not just of technical issues, device integration and application development, but also of service marketing to end customers and the development of a winning proposition. Creativity Software's "lifecycle" approach differentiated it from other potential vendors and allowed it to become Roshan's trusted partner for the project. The launch of TrackCare is particularly instructive for other operators, particularly those in regions where such solutions are relatively undeveloped. Although vehicle tracking services are relatively well developed in many countries, few mobile network operators (MNOs) have capitalised on the revenue generation opportunity behind the service. In fact, vehicle tracking services are, in the main, offered by third party service providers. Market research, however, suggests that such third party providers can only reach around 15% of the total market available, as customer acquisition costs tend to inhibit the potential to address the whole of the market. MNOs are in a unique position to service the entire enterprise market with advanced vehicle tracking solutions that utilise different location technologies (for example, GPS, Enhanced Cell-ID, and SIMapplets) in a cost effective manner. With Roshan's TrackCare providing a model, there is significant opportunity for other operators to digest the lessons of this innovative, all-encompassing service and to consider launching their own versions. Why Creativity Software?ApplicationsInfrastructure ProductsLawful InterceptLocation Based TechnologyLBS Success StoriesOur PartnersNewsContactSite Map © Creativity Software. River Reach, 31-35 High Street, Kingston-upon-Thames. Registered in England No. 4212878.

Selasa, 25 Oktober 2011

www.dnsexit.com

DNS Exit provides 100% free static or dynamic DNS Services to your top level domains. Our DNS still keeps 100% uptime history since we started in 1998. Dynamic DNS allows you to run your own website, ftp, or mail servers via DSL, Cable Modem lines with dynamic IP. To start with dynamic DNS experience, you may get one of our New Service Free Second-Level Domains. If you are new to DNS and don't how to create it, no problem, our DNS Tools will guide you through the whole setup process. You will be amazed by how easy it is to setup DNS with our tools. If you are still looking for a domain name, provides domain registration for only $12.95/year. We provide domain control and DNS management panel to manage your domains through your member account. Web Hosting click for more information.. Web Site Hosting is as low as $2.95 / month. Unlimited mail addresses with POP3/IMAP/WebMail. PHP4, PHP5, Perl, Python support and MySQL database. Domain Name Registration click for more information.. We are ICANN accredited registrar. Register your domain and use our free dynamic DNS to start your own website, mail server, or ftp server through broadband connection. Domain Name Transfers click for more information.. Already got your domain name with another registrar, you can transfer the domain to us and manage everything about your domain in one location. DNS Services & Management FREE click for more information.. Manage your domain DNS from our easy-to-use web interface FREE of charge, Our DNS supports country code and specialty domains such as .tv, .cc, .bz, .ws, .info, .biz, .name. Dynamic DNS Service FREE click for more information.. No static IP? No problem. 100% FREE. With dynamic DNS service, you can map your domain names to servers connected via DSL, cable modem, or any other service that does not provide you with a static IP address. Our Dynamic DNS have your IP updated in less than 2 minutes, which is the fastest in industry. Mail Hosting (POP3 + SMTP Relay) click for more information.. Completed mail service for your domain with POP3 + SMTP relay. Supports IMAP with webmail access. Unlimited mailboxes and mail forwards with Virus/Spam Filters. Mail Relay Outbound click for more information.. Mail Outbound Relay on both standard and non-standard SMTP ports (25, 26, 940, 8001, 2525 and 80). This is beneficial to a traveler on the road, whose ISP does not provide a server which allows remotely authenticated relaying, or whose ISP blocks outbound SMTP port (25). Mail Redirection click for more information.. Is your ISP blocking email port 25 and you still want to maintain your own email server? Mail Redirection dedicates our email server as the primary MX for your domain while emails will be routed to your server at none-standard opened SMTP ports. You get the redundancy to your emails because your emails will be spooled for 5 days on our server while your mail server is unavailable. Mail Backup MX click for more information.. Gives your mail server the backup it needs those times when it's unavailable. In case your mail server is down, our mail servers spool your emails and deliver them to your primary email server once it is available again. Mail Forwarding click for more information.. Have your own domain name and want to have email addresses for the domain? You don't need to run any mail server. We forward your domain emails to existing email addresses. URL Forwarding click for more information.. If your ISP blocks www port 80 and you still want to host your own web site. Or you already have an existing web site with a hard-to-remember URL address. The service will forward your domain to existing websites. Website Templates click for more information.. Need a nice looking website? We have made website designs simple with thousands of Website Templates to fit your needs. Just find the design of your choice and make the purchase. You will receive all the source code for PhotoShop and Fireworks), html codes , and instructions to customize for your own use. domain domain domain What is new? 01/22/2010 more. SRV Records on DNS are supported 08/25/2009 more. .CN Top Level Domain registration now available 11/11/2008 more. Free Second-Level Domains available 10/31/2008 more. Release of Email Marketing Site - MailRelease.com Dynamic DNS Clients To have IP automatically updated: Windows All Platforms IP Updater This client is basically 100% automatic and dummy proof. Linux/Unix/MacOSX IP Update The program is written in Perl and can be run as a daemon. Multiple hosts can be updated by the program. Source : ©1998 - 2011 by dnsExit.Com A Subsidiary of NetDorm, Inc. All Rights Reserverd Tel: (513) 474-4105 Netdorm, Inc. 7721 Five Mile Road, Suite 147 Cincinnati, Ohio 45230, USA

computerhope.com

Jumat, 21 Oktober 2011

animation.about.com

Free Computer Animation Programs Want to try before you buy, or looking for something simple but functional with no strings attached? Here's a list of various animation software packages available for download, and reviews of several applications. Some are entirely free, some are shareware, some are free with limited functions (with more available after paying), and some are free trials that either expire after time or come with certain critical options disabled. 2D Animation Software Software: Adobe AfterEffects Publisher: Adobe License: Free Trial Comments: Motion graphics and visual effects for film and media. Software: Animator-9 3.6 Publisher: Key Technology License: Free Comments: Make animated GIFs from your digital camera. Software: Animator-DV (Read a Review from Animation@About.com!) Publisher: AnimatorHD License: Free Trial Comments: Stop-motion animation on your computer. Software: Anime Studio Pro 5 (Read a Review from Animation@About.com!) Publisher: MySmithMicro License: Free Trial Comments: Studio-style animation program. Software: AniS 1.0 Publisher: Tom Whittaker License: Free Comments: Simple image manipulation for the web. Software: Beneton Movie GIF (Read a Review from Animation@About.com!) Publisher: Beneton Software License: Free Comments: Basic GIF animation software. Software: Cylekx 2.9 (Read a Review from Animation@About.com!) Publisher: Cylekx License: Free Comments: Graphics and animation program. Software: DigiCel Flipbook 6 (Read a Review from Animation@About.com!) Publisher: DigiCel, Inc. License: Free Trial Comments: Industry standard studio animation program. Software: Flash Effect Site Builder (Read a Review from Animation@About.com!) Publisher: Go2Share.net (Warning: website not safe for work) License: Free Trial Comments: More of a website builder, but still uses Flash animation. Software: Flash Media Show (Read a Review from Animation@About.com!) Publisher: SourceTec Software License: Free (Standard Edition) Comments: Flash slideshow builder and exporter. Software: FotoMorph (Read a Review from Animation@About.com!) Publisher: Digital Photo Software License: Free Comments: Image morphing and animation software. Software: GifSplitter 2 (Read a Review from Animation@About.com!) Publisher: XoYo Software License: Free Comments: Simple GIF animation and splitting program. Software: Jumpwel Publisher: Phildes License: Free Comments: Basic object manipulator for use in HTML; uses Java applets. Software: KoolMoves 7.0 (Read a Review from Animation@About.com!) Publisher: KoolMoves License: Free Trial Comments: Alternative Flash animation program. Software: Adobe Flash Publisher: Adobe License: Free Trial Comments: The leading name in 2D vector animation. Software: Macromedia Director Publisher: Macromedia License: Free Trial Comments: Create interactive ShockWave content. Software: Sqirlz Lite 1.1d Publisher: xiberpix License: Free Comments: Animated image distorter that exports in AVI format. Software: Sqirlz Morph 2.1 (Read a Review from Animation@About.com!) Publisher: xiberpix License: Free Comments: Animated image morpher and blender. Capable of outputting in Flash format. Software: The TAB Manga (Read a Review from Animation@About.com!) Publisher: The TAB License: Free Trial Comments: Children's animation program. Software: Toon Boom Animate (Read a Review from Animation@About.com!) Publisher: Toon Boom License: Free Trial Comments: Industry-leading professional studio animation program. Software: Ulead GIF Animator 5 (Read a Review from Animation@About.com!) Publisher: Corel License: Free Trial Comments: Full-featured GIF animation software. 3D Animation Software Software: 3D Studio Max 7.0 Publisher: Discreet License: Free Trial Comments: Version 7.0 of the award-winning 3D modeling and animation software package. Also comes with trials of Character Studio and Mental Ray. Software: Cyberdelia (Read a Review from Animation@About.com!) Publisher: Askoh.com License: Free Comments: 3D Animation with support for exporting into Macromedia Shockwave. Software: FreeCAD 8.0 Publisher: Askoh.com License: Free Comments: Bit of a beginner's 3D CAD and simulation program. Software: Gmax Publisher: Discreet License: Free Comments: Oh, man. It's every gamer's dream: a free 3D program that lets you make your own modifications, customizations, and models for Gmax-ready video games. Based on 3D Studio Max. Software: Maya 6.5 Publisher: Alias WaveFront License: Free Trial Comments: The latest version of an industry leader in 3D modeling and animation. Software: Serif 3D Plus Publisher: Serif License: Free Comments: Allows animated shapes and landscapes. Software: Special Effects 3.2 Publisher: Mathematically Beautiful ScreenSavers License: Free Comments: Very limited range of pre-set animations controlled by user preferences. Software: Touch Art Sampler 017 Publisher: Derivative License: Free Comments: More of a VJ/synthesizer studio than anything else, but still lets you play with animations. Looks rather fun. Software: TrueSpace 3.2 Publisher: Caligari License: Free Comments: Full 3D rendering and output. Seems completely free, though you have to register to get an unlock code on the website. Cross-compatible with many programs. Related Articles * Animation Software Review: Cyberdelia 3D Animation Software * Animation Software Review: Xara 3D 6.0 Animation Software * How to Choose an Animation Software Package * Is Flash the Only 2D Animation Software? * Know Your Rights and Restrictions. Read the EULA. Adrien-Luc Sanders Adrien-Luc Sanders Animation Guide * Sign up for My Newsletter * Headlines * Forum Advertisement Related Video PowerPoint Animation PowerPoint Animation Introduction to Flash 8 Workspace Introduction to Flash 8 Workspace Import Video Into Flash Import Video Into Flash More VideosSee All About.com Videos Sponsored Links Run Your Ads on GoogleRp. 300.000 in Free Ads To Drive More Traffic To Your Website Today!www.Google.com/AdWords Ray Rover Motion GraphicsDownload For Free And Use Trial Min Over 3100 Preset Screens To Seewww.taylorentertainment.biz Gif AnimatorCreate an animation for a Mobile, Desktop, Website - Application!goodplayer.pl Efield SoftwareA complete simulation environment for 3D electromagnetic applicationswww.efieldsolutions.com Related Searches flash animation software 2d animation software adobe aftereffects digital camera software tom whittaker studio animation Explore Animation Must Reads * Money-Saving Tips for Animators * 10 Essential Animation Art Supplies * Animation Showcase Submission * Free & Trial Animation Programs * Traditional Animation in Flash Most Popular * Free Animation Programs * Embedding an SWF in a Web Page * Flash Basic Walk Cycle * Ask the Magic 8-Ball - Demo * Your First Animation See More About: * cost-effective animating * free animation software * 2d animation software * 3d animation software * animation trial evaluations By Category * Flash Animation Tutorials * 3D Animation Tutorials * Other Animation Tutorials * Movie and Game Animation * Software Reviews * Tips and Tricks * Industry Profiles * History of Animation * Education Resources * Career Guides * Reference Materials * Media Gallery * Related Topics * FAQs and Glossary Terms ©2011 About.com. All rights reserved. A part of The New York Times Company.

Senin, 17 Oktober 2011

http://www.webopedia.com

The Five Generations of Computers Each generation of computer is characterized by a major technological development that fundamentally changed the way computers operate, resulting in increasingly smaller, cheaper, more powerful and more efficient and reliable devices. The history of computer development is often referred to in reference to the different generations of computing devices. Each generation of computer is characterized by a major technological development that fundamentally changed the way computers operate, resulting in increasingly smaller, cheaper, more powerful and more efficient and reliable devices. Read about each generation and the developments that led to the current devices that we use today. Key Terms: computer, magnetic drums, binary, integrated circuit, semiconductor, nanotechnology First Generation (1940-1956) Vacuum Tubes Sponsored Server virtualization is growing in popularity, but the technology for securing it lags.: To protect your virtual network, read “3 Ways to Secure Your Virtualized Data Center” now. The first computers used vacuum tubes for circuitry and magnetic drums for memory, and were often enormous, taking up entire rooms. They were very expensive to operate and in addition to using a great deal of electricity, generated a lot of heat, which was often the cause of malfunctions. First generation computers relied on machine language, the lowest-level programming language understood by computers, to perform operations, and they could only solve one problem at a time. Input was based on punched cards and paper tape, and output was displayed on printouts. The UNIVAC and ENIAC computers are examples of first-generation computing devices. The UNIVAC was the first commercial computer delivered to a business client, the U.S. Census Bureau in 1951. Second Generation (1956-1963) Transistors Transistors replaced vacuum tubes and ushered in the second generation of computers. The transistor was invented in 1947 but did not see widespread use in computers until the late 1950s. The transistor was far superior to the vacuum tube, allowing computers to become smaller, faster, cheaper, more energy-efficient and more reliable than their first-generation predecessors. Though the transistor still generated a great deal of heat that subjected the computer to damage, it was a vast improvement over the vacuum tube. Second-generation computers still relied on punched cards for input and printouts for output. Second-generation computers moved from cryptic binary machine language to symbolic, or assembly, languages, which allowed programmers to specify instructions in words. High-level programming languages were also being developed at this time, such as early versions of COBOL and FORTRAN. These were also the first computers that stored their instructions in their memory, which moved from a magnetic drum to magnetic core technology. The first computers of this generation were developed for the atomic energy industry. Third Generation (1964-1971) Integrated Circuits The development of the integrated circuit was the hallmark of the third generation of computers. Transistors were miniaturized and placed on silicon chips, called semiconductors, which drastically increased the speed and efficiency of computers. Instead of punched cards and printouts, users interacted with third generation computers through keyboards and monitors and interfaced with an operating system, which allowed the device to run many different applications at one time with a central program that monitored the memory. Computers for the first time became accessible to a mass audience because they were smaller and cheaper than their predecessors. Fourth Generation (1971-Present) Microprocessors The microprocessor brought the fourth generation of computers, as thousands of integrated circuits were built onto a single silicon chip. What in the first generation filled an entire room could now fit in the palm of the hand. The Intel 4004 chip, developed in 1971, located all the components of the computer—from the central processing unit and memory to input/output controls—on a single chip. In 1981 IBM introduced its first computer for the home user, and in 1984 Apple introduced the Macintosh. Microprocessors also moved out of the realm of desktop computers and into many areas of life as more and more everyday products began to use microprocessors. As these small computers became more powerful, they could be linked together to form networks, which eventually led to the development of the Internet. Fourth generation computers also saw the development of GUIs, the mouse and handheld devices. Fifth Generation (Present and Beyond) Artificial Intelligence Fifth generation computing devices, based on artificial intelligence, are still in development, though there are some applications, such as voice recognition, that are being used today. The use of parallel processing and superconductors is helping to make artificial intelligence a reality. Quantum computation and molecular and nanotechnology will radically change the face of computers in years to come. The goal of fifth-generation computing is to develop devices that respond to natural language input and are capable of learning and self-organization. DID YOU KNOW...? An integrated circuit (IC) is a small electronic device made out of a semiconductor material. The first integrated circuit was developed in the 1950s by Jack Kilby of Texas Instruments and Robert Noyce of Fairchild Semiconductor. About Internet.com Copyright 2011 QuinStreet Inc. All Rights Reserved. Legal Notices, Licensing, Permissions, Privacy Policy. Advertise | Newsletters | E-mail Offers Solutions

Jumat, 14 Oktober 2011

The Advantages to Use Wifi for Efficiency

Using Internet technology is expensive in developing country and poor country. The causes are varieties, beside lack of network infrastructure, expensive hardware and software, although software is developed to open source now days. Based on World Summit Information Society (WSIS) at Jenewa, followed by 150 countries and 12000 degelation world wide, declared that developing country and poor country should get target to be Global Information Society in 20015. The delegation sure, people that know much global information, get achieve Millennium Development Gold (MDG) target easily. Finally, economy improvement will be achieved. Poor countries that has digital divide problem, quickest way to achieve the target, must find cheap network infrastructure. WIFI or wireless fidelity is solution to implement it. Indonesia, as one of developing country at south east Asia is successful to implement it. We are sure, the infrastructure obstacles are difference between one country and others. We can tell, the benefits to use WIFI, 1.WIFI can be developed without cable and connect building to building, use radio wave with free frequency 2,4 GHZ. WIFI has send and receive capacity until 54Mbps. 2.WIFI network use access point / hot spot, can communicate to all personal computer and laptop, Pentium 3, memory 256 MB. Coaxial cable to use from antenna to server. Wireless client: PCMACIA / PC Card. Gateway, server, modem, router, proxy. 3.The software that run to the WIFI network usually include. Use windows and Linux and web base system. 4.Hot spot can develop at open yard so that people can access Internet freely. Add Streetdirectory.com to your favourites! - Make Streetdirectory.com your homepage About » Widgets | T&C | Feedback For Businesses » Free Ads | Online Advertising | Wall Maps | SMS Marketing | Text Ads Hotline : Sales 6474 4005 | Marketing & Business Opportunities : 65942755 | (Mon to Fri, 9am to 6pm) Streetdirectory.com, ranked Number 1 Travel Guide in Singapore provides a variety of customized Singapore street directory, Asia hotels, Singapore Images, Singapore real estate, Search for Singapore Private Limited Companies, Singapore Wine and Dine Guide, Bus Guide and S.E.A Travel Guide. Our travel guide includes Singapore Travel Guide, Bali Travel Guide, Bali Maps, Jakarta Travel Guide, KL Travel Guide, Malaysia Guide, Johor Guide, Malacca Guide and is widely used by travelers, expats and tourists around the world. Singapore Jobs Streetdirectory.com Streetdirectory.co.id Streetdirectory.com.my © 2011 Streetdirectory

Kamis, 13 Oktober 2011

databases.about.com

Database Design A carefully thought-out database design forms the foundation for future success. These links will help you plan your database designs to maintain performance and integrity through future growth. Compound Key What is a compound key? Find out in the About Databases glossary! Default Values Looking for a description of default values and constraints in databases? The About Databases Glossary provides an easy to understand description. Sponsored Links Database Design SoftwareMedical Technology Devices That Capture Personal Health Information searchhealthit.techtarget.com Should I Normalize My Database? Database normalization is one of the sacred cows of application development. Every undergraduate programming course you’ve taken or book you’ve read likely preaches about the importance of normalizing databases in an almost religious fashion. You’re made to feel like failure to normalize a database is tantamount to violating one of the laws of... Database Relationships Looking for a definition of a database relationship? Check out the About Databases glossary definition! Many-to-Many Relationships Looking for a definition of many-to-many database relationships? Read our definition in the About Databases glossary! One-to-Many Relationships Looking for a definition of one-to-many database relationships? Read our definition in the About Databases glossary! One-to-One Relationships Looking for a definition of one-to-one database relationships? Read our definition in the About Databases glossary! Normalizing Your Database: Third Normal Form (3NF) In our first article, we looked at the basic requirements of 3NF. Here they are again to refresh your memory: meet the requirements of 1NF and 2NF and remove columns that are not fully dependent upon the primary key. Normalizing Your Database: First Normal Form (1NF) In this article, we begin our look at the first of three major normal forms -- first normal form (otherwise known as 1NF). What are Database Dependencies? Database dependencies are a topic that often confuses both students and database professionals alike. Fortunately, they are not that complicated and can best be illustrated through the use of a number of examples. In this article, we examine common database dependency types. Database Keys As you may already know, databases use tables to organize information. Each table consists of a number of rows, each of which corresponds to a single database record. So, how do databases keep all of these records straight? It’s through the use of keys. What is a Database? Databases are designed to offer an organized mechanism for storing, managing and retrieving information. They do so through the use of tables. If you’re familiar with spreadsheets like Microsoft Excel, you’re probably already accustomed to storing data in tabular form. It’s not much of a stretch to make the leap from spreadsheets to databases. Object Oriented Databases Looking for a definition of Object Oriented Databases? Find it here! Stored Procedure Definition Looking for a definition of the database term stored procedure? Find it here in the About Databases glossary. Choosing a Primary Key Databases depend upon keys to store, sort and compare records. If you’ve been around databases for a while, you’ve probably heard about many different types of keys – primary keys, candidate keys, and foreign keys. When you create a new database table, you’re asked to select one primary key that will uniquely identify records stored in that table. Normalizing Your Database: Second Normal Form (2NF) Second Normal Form allows you to enhance the normalization of your database. In this article, we explore the requirements of 2NF and the process of normalizing your database. The ACID Model All database management systems should share four characteristics: Atomicity, Consistency, Isolation and Durability. Database Normalization Basics Database normalization can save storage space and ensure the consistency of your data. Learn the basics in this introductory article. Two-Tier or n-Tier? What's best for your situation? Two-tier, three-tier or n-tier databases? Find out here! Database Fundamentals Confused by the world of databases? Looking for a concise description of how databases work? Look no further! This article introduces you to the wonderful world of databases. Choosing a Database: Defining your Requirements In the first installment of our database selection guide, we walk you through the process of defining the requirements for your database platform. Choosing a Database: Desktop Databases Is a DBMS like Microsoft Access, FoxPro, FileMaker Pro or Lotus Approach sufficient for your needs? Find out as we explore the world of desktop databases. Choosing a Database: Server Databases Does your organization require a server-based database like Oracle or Microsoft SQL Server? Join us as we explore the world of these high-performance systems. Database Normalization Basics Database normalization can save storage space and ensure the consistency of your data. Learn the basics in this introductory article. Database Normalization: First Normal Form (1NF) Learn how to ensure that your database meets the fundamental requirements of first normal form (1NF). Database Normalization: Second Normal Form (2NF) Learn how to ensure that your database meets the data reduction requirements of second normal form (2NF). Top Five Desktop Databases There are a lot of desktop databases on the market. Which ones are the cream of the crop? Find out here! Case Study in Database Design This case study in automating billing procedures at the University of North Carolina provides a great overview of the database design process. Common Database Design Mistakes Louis Davidson brings us an informative look at the most common mistakes made by database designers. Database Design from MIT The Massachusetts Institute of Technology offers lecture notes on database design including a case study from the City of Cambridge's Fire Department. Database Normalization Follow this link for a comprehensive look at database normalization. A great resource for database designers of all levels. Database Normalization Course Database normalization lecture slides from a design course at the University of California at Berkeley. Entity-Relationship Diagrams Simon Frasier University presents an illustrated introduction to entity-relationship (ER) diagrams. Fundamentals of Relational Database Design This lengthy article covers the fundamentals of RDBMS design. Topics covered include normalization, integrity checking, keys and business rules. Relational Database Keys Applied Information Science provides an in-depth tutorial on the various types of keys used in relational databases. Database Relationships: An Introduction To Foreign Keys, Joins and E-R Diagrams Relationships allow you to describe the connections between different database tables in powerful ways. Once you’ve described the relationships between your tables, you can later leverage that information to perform powerful cross-table queries, known as joins. ©2011 About.com. All rights reserved. A part of The New York Times Company.

http://www.realsoftwaredevelopment.com/

Software Development in the Real World Last updated Friday, October 14th 2011 Software Development in the Real World Subscription Next XBOX 360 is Under Development Posted by miguelcarrasco in Wednesday, October 12th 2011 Topics: Microsoft, XBOX Tags: Microsoft, xbox Comments (1) When a new XBOX 360 arrives before Christmas 2012, it will usher in a new era of software development opportunities for many of you. The ability to write applications for XBOX 360 and place them in the Microsoft Marketplace is going to be an awesome opportunity. Game development studios are already underway in their development efforts to bring the next generation video games to your television sets near you. Rare, the famous video game studio that brought you games like Killer Instinct and Donkey Kong Country are already working on some new and exciting games. People within Microsoft have recently updated their LinkedIn status to reflect their new roles within Microsoft that clearly shows the next XBOX 360 is about a year away. Many questions should be answered at next years E3 event, but for now, it’s always fun to speculate what the future of video gaming may hold. To think that the current XBOX 360 is nearly 7 years old and still the number one selling video game console is absolutely remarkable. I’m not sure what the next XBOX is going to hold for us, but what I do know is the plans are to make it the centerpiece of our home’s entertainment system. Microsoft Releases Official Windows Phone 7.5 Development Tools Posted by miguelcarrasco in Saturday, October 1st 2011 Topics: Microsoft, Windows Phone 7 Tags: mango, miguel carrasco, windows phone, youtube Comments (34) Windows Phone 7.5 is now being released across the globe, and it is a smoking new operating system that brings the feature set of Windows Phone up to the iOS/Android level. With that, Microsoft has released Windows Phone 7.1 SDK which allows developers to code for the Windows Phone 7.5 Mango without the need of using beta tools. The Windows Phone 7.1 SDK provides software developers all the tools they need to build amazing Windows Phone 7.5 Mango applications, as well as games. The list of new features in Windows Phone 7.5 is incredibly impressive, so why not sit back and watch a quick 10 minute video that shows you all the fantastic features the Windows Phone 7.5 provides to consumers. While you watch, download the new SDK here. For more details of how Windows Phone 7.5 can help you get control of social media, make sure you read the detailed article on Miguel Carrasco dot Com. Windows 8 and Software Developers Posted by miguelcarrasco in Wednesday, September 21st 2011 Topics: Microsoft Expression, Videos, Windows Phone 7, WPF, XAML Comments (41) As a Software Developer, I was stunned at what I saw at Microsoft Build last week. And it was a stunned look of excitement. Last week Microsoft unveiled Windows 8, a revolutionary new touch centric operating system that will change the way you work forever. I was lucky enough to take part in Microsoft Build, and was able to record a full demo of Windows 8 Slate Device, be interviewed by Telerik TV on my thoughts of Microsoft Build and Windows 8 and what it means to software developers, and also record a podcast with Windows Observer! Here are the links to those videos and podcasts, because they are way more fun to watch and listen to! Listen to the Windows Observer PodCast Kinect Software Places People on Buildings Posted by miguelcarrasco in Tuesday, September 6th 2011 Topics: Microsoft Tags: kinect Comments (63) As a software developer I’m always looking for new and interesting technology that I can write software for. When I first saw the Kinect, my mind was blown. When I continue to see the new levels of innovation that other software developers are going to with the technology, I get even more excited. A few days ago I was lucky enough to get a demonstration of one of those cool technologies that just make you go “WOW”. It’s one of those things that you have to experience to understand, but PO-MO Inc. basically created software to take the information being gathered from the Kinect, translate the information into amazing graphics, and then throwing up the animated artwork onto a building. People walking by get to dance and see themselves on a building. It’s all very surreal and awesome at the same time. Check out a quick interview I did with PO-MO Inc. founder, Meghan Athavale. New Digital Marketing and Technology Blog You Have To Check Out Posted by miguelcarrasco in Wednesday, August 3rd 2011 Topics: Software Development Comments (119) Over the years I have been spending more and more time focusing on digital marketing, and the intersection points between Business Strategy, Technology, and Marketing. While I am still extremely passionate about software development, I needed a separate avenue to express ideas, thoughts, perspectives, and lessons learned over the last 15 years. I would be honoured if all of you would join me at my new blog: http://www.miguelcarrasco.com In conjunction with the new blog, I am also launching a Video Cast Series focused on Social Media, Technology, and Digital Marketing in general. I will try and keep it engaging and exciting so make sure you head to the new blog to catch all the latest episodes! Here is a sneak peak at “Episode 0 – Focus Your Twitter Conversations” « Older Entries Our Sponsors * Latest Development Posts o Next XBOX 360 is Under Development o Microsoft Releases Official Windows Phone 7.5 Development Tools o Windows 8 and Software Developers o Kinect Software Places People on Buildings o New Digital Marketing and Technology Blog You Have To Check Out * Latest Comments o Cheap Jerseys on Silverlight and the UFC o Cheap Jerseys on Silverlight vs. Flash SmackDown o Cheap Jerseys on Battle of the Titans: The Silverlight and Flash SmackDown o Cheap Jerseys on NCAA March Madness Streaming with Silverlight o Cheap Jerseys on Watch Obama’s Inauguration ©2007-2011 Software Development in the Real World Software Development in the Real World RSS Count Valid XHTML | Valid CSS

mikrokontroler.tripod.com/8051

Mode Pengalamatan Mode pengalamatan merujuk pada bagaimana pemrogram mengalamati suatu lokasi memori. Setiap mode pengalamatan memberikan fleksibilitas khusus yang sangat penting. Mode pengalamatan ini meliputi immediate addressing, direct addressing, dan indirect addressing. Immediate Addressing dan Direct Addressing Mode pengalamatan immediate addressing sangat umum dipakai karena harga yang akan disimpan dalam memori langsung mengikuti kode operasi dalam memori. Dengan kata lain, tidak diperlukan pengambilan harga dari alamat lain untuk disimpan. Contohnya: MOV A,#20h. Dalam instruksi tersebut, akumulator akan diisi dengan harga yang langsung mengikutinya, dalam hal ini 20h. Mode ini sangatlah cepat karena harga yang dipakai langsung tersedia. Dalam mode pengalamatan direct addressing, harga yang akan dipakai diambil langsung dalam alamat memori lain. Contohnya: MOV A,30h. Dalam instruksi ini akan dibaca data dari RAM internal dengan alamat 30h dan kemudian disimpan dalam akumulator. Mode pengalamatan ini cukup cepat, meskipun harga yang didapat tidak langsung seperti immediate, namun cukup cepat karena disimpan dalam RAM internal. Demikian pula akan lebih mudah menggunakan mode ini daripada mode immediate karena harga yang didapat bisa dari lokasi memori yang mungkin variabel. Indirect Addressing Mode pengalamatan indirect addressing sangat berguna karena dapat memberikan fleksibilitas tinggi dalam mengalamati suatu harga. Mode ini pula satu-satunya cara untuk mengakses 128 byte lebih dari RAM internal pada keluarga 8052. Contoh: MOV A,@R0. Dalam instruksi tersebut, 89C51 akan mengambil harga yang berada pada alamat memori yang ditunjukkan oleh isi dari R0 dan kemudian mengisikannya ke akumulator. Mode pengalamatan indirect addressing selalu merujuk pada RAM internal dan tidak pernah merujuk pada SFR. Karena itu, menggunakan mode ini untuk mengalamati alamat lebih dari 7Fh hanya digunakan untuk keluarga 8052 yang memiliki 256 byte spasi RAM internal. Mode pengalamatan memori eksternal menggunakan mode ini dan terdiri atas dua bagian. Bagian yang pertama digunakan untuk mengakses memori eksternal, di mana alamatnya terdapat di dalam DPTR 16 bit. Contohnya: MOVX A,@DPTR atau MOVX @DPTR,A. Bagian kedua mengakses alamat memori eksternal secara 8 bit (1 byte), di mana alamat dari harga yang akan diambil terdapat di dalam register R. Contohnya: MOVX @R0,A. Dalam instruksi tersebut, alamat yang terdapat di dalam register R0 dibaca dahulu dan kemudian harga akumulator ditulis dengan harga yang terdapat pada alamat memori eksternal yang didapat. Karena register R0 hanya dapat menampung alamat dari 00h hingga FFh, maka penggunaan mode pengalamatan eksternal 8 bit ini hanya terbatas pada 256 byte dari memori eksternal. Contact me at: hsutanto@milis.stts.edu Copyright (c) Hermawan Sutanto Written in November 1998 Copying content must have permission from me !

Minggu, 09 Oktober 2011

information superhighway

The global information and communications network that includes the Internet and other networks and switching systems such as telephone networks, cable television networks, and satellite communication networks.

Minggu, 14 Agustus 2011

electronic commerce (ecommerce)

Often referred to as simply ecommerce (or e-commerce) the phrase is used to describe business that is conducted over the Internet using any of the applications that rely on the Internet, such as e-mail, instant messaging, shopping carts, Web services, UDDI, FTP, and EDI, among others. Electronic commerce can be between two businesses transmitting funds, goods, services and/or data or between a business and a customer.

See Understanding "Web Services" in the "Did You Know...?" section of Webopedia.
Also See "How Affiliate Marketing Works" in the "Did You Know..." section of Webopedia.
Also see ECommerce-Guide to News, Reviews and Technology Solutions.

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Minggu, 10 Juli 2011

Electric power transmission

From Wikipedia, the free encyclopedia
"Electric transmission" redirects here. For vehicle transmissions, see diesel-electric transmission.
400 kV high-tension transmission lines near Madrid

Electric power transmission or "high voltage electric transmission" is the bulk transfer of electrical energy, from generating power plants to substations located near population centers. This is distinct from the local wiring between high voltage substations and customers, which is typically referred to as electric power distribution. Transmission lines, when interconnected with each other, become high voltage transmission networks. In the US, these are typically referred to as "power grids" or just "the grid", while in the UK the network is known as the "national grid." North America has three major grids: The Western Interconnection; The Eastern Interconnection and the Electric Reliability Council of Texas (or ERCOT) grid.

Historically, transmission and distribution lines were owned by the same company, but over the last decade or so many countries have liberalized the electricity market in ways that have led to the separation of the electricity transmission business from the distribution business.[1]

Transmission lines mostly use three-phase alternating current (AC), although single phase AC is sometimes used in railway electrification systems. High-voltage direct-current (HVDC) technology is used only for very long distances (typically greater than 400 miles, or 600 km); submarine power cables (typically longer than 30 miles, or 50 km); or for connecting two AC networks that are not synchronized.

Electricity is transmitted at high voltages (110 kV or above) to reduce the energy lost in long distance transmission. Power is usually transmitted through overhead power lines. Underground power transmission has a significantly higher cost and greater operational limitations but is sometimes used in urban areas or sensitive locations.

A key limitation in the distribution of electricity is that, with minor exceptions, electrical energy cannot be stored, and therefore must be generated as needed. A sophisticated system of control is therefore required to ensure electric generation very closely matches the demand. If supply and demand are not in balance, generation plants and transmission equipment can shut down which, in the worst cases, can lead to a major regional blackout, such as occurred in California and the US Northwest in 1996 and in the US Northeast in 1965, 1977 and 2003. To reduce the risk of such failures, electric transmission networks are interconnected into regional, national or continental wide networks thereby providing multiple redundant alternate routes for power to flow should (weather or equipment) failures occur. Much analysis is done by transmission companies to determine the maximum reliable capacity of each line which is mostly less than its physical or thermal limit, to ensure spare capacity is available should there be any such failure in another part of the network.
Diagram of an electrical system.
Contents
[hide]

1 Overhead transmission
2 Underground transmission
3 History
4 Bulk power transmission
4.1 Grid input
4.2 Losses
4.3 Subtransmission
4.4 Transmission grid exit
5 High-voltage direct current
6 Limitations
7 Control
7.1 Load balancing
7.2 Failure protection
8 Communications
9 Electricity market reform
10 Cost of electric power transmission
11 Merchant transmission
12 Health concerns
13 Government policy
14 Special transmission
14.1 Grids for railways
14.2 Superconducting cables
14.3 Single wire earth return
14.4 Wireless power transmission
15 Security of control systems
16 Records
17 See also
18 Notes
19 Further reading
20 External links

[edit] Overhead transmission
Main article: Overhead power line
Contiguous United States power transmission grid consists of 300,000 km of lines operated by 500 companies.

High-voltage overhead conductors are not covered by insulation. The conductor material is nearly always an aluminium alloy, made into several strands and possibly reinforced with steel strands. Copper was sometimes used for overhead transmission but aluminium is lower in weight for only marginally reduced performance, and much lower in cost. Overhead conductors are a commodity supplied by several companies worldwide. Improved conductor material and shapes are regularly used to allow increased capacity and modernize transmission circuits. Conductor sizes range from 12 mm2 (#6 American wire gauge) to 750 mm2 (1,590,000 circular mils area), with varying resistance and current-carrying capacity. Thicker wires would lead to a relatively small increase in capacity due to the skin effect, that causes most of the current to flow close to the surface of the wire.

Today, transmission-level voltages are usually considered to be 110 kV and above. Lower voltages such as 66 kV and 33 kV are usually considered subtransmission voltages but are occasionally used on long lines with light loads. Voltages less than 33 kV are usually used for distribution. Voltages above 230 kV are considered extra high voltage and require different designs compared to equipment used at lower voltages.

Since overhead transmission lines are uninsulated, design of these lines requires minimum clearances to be observed to maintain safety. Adverse weather conditions of high wind and low temperatures can lead to power outages: wind speeds as low as 23 knots (43 km/h) can permit conductors to encroach operating clearances, resulting in a flashover and loss of supply.[2] Oscillatory motion of the physical line can be termed gallop or flutter depending on the frequency and amplitude of oscillation.
High Voltage Lines in Washington State
[edit] Underground transmission
Main article: Undergrounding

Electric power can also be transmitted by underground power cables instead of overhead power lines.
[edit] History
Main article: History of electric power transmission
New York City streets in 1890. Besides telegraph lines, multiple electric lines were required for each class of device requiring different voltages.

In the early days of commercial electric power, transmission of electric power at the same voltage as used by lighting and mechanical loads restricted the distance between generating plant and consumers. In 1882, generation was with direct current (DC), which could not easily be increased in voltage for long-distance transmission. Different classes of loads (for example, lighting, fixed motors, and traction/railway systems) required different voltages, and so used different generators and circuits.[3][page needed]

Due to this specialization of lines and because transmission was so inefficient that generators needed to be near their loads, it seemed at the time that the industry would develop into what is now known as a distributed generation system with large numbers of small generators located nearby their loads.[4]

In 1886 in Great Barrington, Massachusetts, a 1 kV alternating current (AC) distribution system was installed. That same year, AC power at 2 kV, transmitted 30 km, was installed at Cerchi, Italy. At an AIEE meeting on May 16, 1888, Nikola Tesla delivered a lecture entitled A New System of Alternating Current Motors and Transformers, describing the equipment which allowed efficient generation and use of polyphase alternating currents. The transformer, and Tesla's polyphase and single-phase induction motors, were essential for a combined AC distribution system for both lighting and machinery. Ownership of the rights to the Tesla patents was a key advantage to the Westinghouse Company in offering a complete alternating current power system for both lighting and power.
Nikola Tesla's Alternating current polyphase generators on display at the 1893 World's Fair in Chicago. Tesla's polyphase innovations revolutionized transmission.

Regarded as one of the most influential electrical innovations, the universal system used transformers to step-up voltage from generators to high-voltage transmission lines, and then to step-down voltage to local distribution circuits or industrial customers.[3] By a suitable choice of utility frequency, both lighting and motor loads could be served. Rotary converters and later mercury-arc valves and other rectifier equipment allowed DC to be provided where needed. Generating stations and loads using different frequencies could be interconnected using rotary converters. By using common generating plants for every type of load, important economies of scale were achieved, lower overall capital investment was required, load factor on each plant was increased allowing for higher efficiency, a lower cost for the consumer and increased overall use of electric power.

By allowing multiple generating plants to be interconnected over a wide area, electricity production cost was reduced. The most efficient available plants could be used to supply the varying loads during the day. Reliability was improved and capital investment cost was reduced, since stand-by generating capacity could be shared over many more customers and a wider geographic area. Remote and low-cost sources of energy, such as hydroelectric power or mine-mouth coal, could be exploited to lower energy production cost.[3]

The first transmission of three-phase alternating current using high voltage took place in 1891 during the international electricity exhibition in Frankfurt. A 25 kV transmission line, approximately 175 km long, connected Lauffen on the Neckar and Frankfurt.

Voltages used for electric power transmission increased throughout the 20th century. By 1914, fifty-five transmission systems each operating at more than 70 kV were in service. The highest voltage then used was 150 kV.[5]

The rapid industrialization in the 20th century made electrical transmission lines and grids a critical part of the infrastructure in most industrialized nations. Interconnection of local generation plants and small distribution networks was greatly spurred by the requirements of World War I, where large electrical generating plants were built by governments to provide power to munitions factories. Later these plants were connected to supply civil loads through long-distance transmission.[6]
[edit] Bulk power transmission
A transmission substation decreases the voltage of incoming electricity, allowing it to connect from long distance high voltage transmission, to local lower voltage distribution. It also reroutes power to other transmission lines that serve local markets. A transmission substation may include phase-shifting or voltage regulating transformers. This is the PacifiCorp Hale Substation, Orem, Utah, USA.

Engineers design transmission networks to transport the energy as efficiently as feasible, while at the same time taking into account economic factors, network safety and redundancy. These networks use components such as power lines, cables, circuit breakers, switches and transformers. The transmission network is usually administered on a regional basis by an entity such as a regional transmission organization or transmission system operator.

Transmission efficiency is hugely improved by devices that increase the voltage, and proportionately reduce the current in the conductors, thus keeping the power transmitted nearly equal to the power input. The reduced current flowing through the line reduces the losses in the conductors. According to Joule's Law, energy losses are directly proportional to the square of the current. Thus, reducing the current by a factor of 2 will lower the energy lost to conductor resistance by a factor of 4.

This change in voltage is usually achieved in AC circuits using a step-up transformer. DC systems require relatively costly conversion equipment which may be economically justified for particular projects, but are less common currently.

A transmission grid is a network of power stations, transmission circuits, and substations. Energy is usually transmitted within a grid with three-phase AC. Single phase AC is used only for distribution to end users since it is not usable for large polyphase induction motors. In the 19th century, two-phase transmission was used but required either three wires with unequal currents or four wires. Higher order phase systems require more than three wires, but deliver marginal benefits.
The synchronous grids of Eurasia.

The capital cost of electric power stations is so high, and electric demand is so variable, that it is often cheaper to import some portion of the needed power than to generate it locally. Because nearby loads are often correlated (hot weather in the Southwest portion of the US might cause many people to use air conditioners), electricity often comes from distant sources. Because of the economics of load balancing, wide area transmission grids now span across countries and even large portions of continents. The web of interconnections between power producers and consumers ensures that power can flow, even if a few links are inoperative.

The unvarying (or slowly varying over many hours) portion of the electric demand is known as the base load and is generally served best by large facilities (which are therefore efficient due to economies of scale) with low variable costs for fuel and operations. Such facilities might be nuclear or coal-fired power stations, or hydroelectric, while other renewable energy sources such as concentrated solar thermal and geothermal power have the potential to provide base load power. Renewable energy sources such as solar photovoltaics, wind, wave, and tidal are, due to their intermittency, not considered "base load" but can still add power to the grid. The remaining power demand, if any, is supplied by peaking power plants, which are typically smaller, faster-responding, and higher cost sources, such as combined cycle or combustion turbine plants fueled by natural gas.
A high-power electrical transmission tower.

Long-distance transmission of electricity (thousands of kilometers) is cheap and efficient, with costs of US$0.005–0.02/kWh (compared to annual averaged large producer costs of US$0.01–0.025/kWh, retail rates upwards of US$0.10/kWh, and multiples of retail for instantaneous suppliers at unpredicted highest demand moments).[7] Thus distant suppliers can be cheaper than local sources (e.g., New York City buys a lot of electricity from Canada). Multiple local sources (even if more expensive and infrequently used) can make the transmission grid more fault tolerant to weather and other disasters that can disconnect distant suppliers.

Long distance transmission allows remote renewable energy resources to be used to displace fossil fuel consumption. Hydro and wind sources can't be moved closer to populous cities, and solar costs are lowest in remote areas where local power needs are minimal. Connection costs alone can determine whether any particular renewable alternative is economically sensible. Costs can be prohibitive for transmission lines, but various proposals for massive infrastructure investment in high capacity, very long distance super grid transmission networks could be recovered with modest usage fees.
[edit] Grid input

At the generating plants the energy is produced at a relatively low voltage between about 2.3 kV and 30 kV, depending on the size of the unit. The generator terminal voltage is then stepped up by the power station transformer to a higher voltage (115 kV to 765 kV AC, varying by country) for transmission over long distances.
[edit] Losses

Transmitting electricity at high voltage reduces the fraction of energy lost to resistance, which is around 7%.[8] For a given amount of power, a higher voltage reduces the current and thus the resistive losses in the conductor. For example, raising the voltage by a factor of 10 reduces the current by a corresponding factor of 10 and therefore the I2R losses by a factor of 100, provided the same sized conductors are used in both cases. Even if the conductor size (cross-sectional area) is reduced 10-fold to match the lower current the I2R losses are still reduced 10-fold. Long distance transmission is typically done with overhead lines at voltages of 115 to 1,200 kV. At extremely high voltages, more than 2 MV between conductor and ground, corona discharge losses are so large that they can offset the lower resistance loss in the line conductors. Measures to reduce corona losses include conductors having large diameter; often hollow to save weight, [9], or bundles of two or more conductors.

Transmission and distribution losses in the USA were estimated at 6.6% in 1997[10] and 6.5% in 2007.[10] In general, losses are estimated from the discrepancy between energy produced (as reported by power plants) and energy sold to end customers; the difference between what is produced and what is consumed constitute transmission and distribution losses.

As of 1980, the longest cost-effective distance for DC electricity was 7,000 km (4,300 mi) (4,000 km (2,500 mi) for AC), although all present transmission lines are considerably shorter.[11]

In an alternating current circuit, the inductance and capacitance of the phase conductors can be significant. The currents that flow in these components of the circuit impedance constitute reactive power, which transmits no energy to the load. Reactive current causes extra losses in the transmission circuit. The ratio of real power (transmitted to the load) to apparent power is the power factor. As reactive current increases, the reactive power increases and the power factor decreases. For systems with low power factors, losses are higher than for systems with high power factors. Utilities add capacitor banks and other components (such as phase-shifting transformers; static VAR compensators; physical transposition of the phase conductors; and flexible AC transmission systems, FACTS) throughout the system to control reactive power flow for reduction of losses and stabilization of system voltage.
[edit] Subtransmission

Subtransmission is part of an electric power transmission system that runs at relatively lower voltages. It is uneconomical to connect all distribution substations to the high main transmission voltage, because the equipment is larger and more expensive. Typically, only larger substations connect with this high voltage. It is stepped down and sent to smaller substations in towns and neighborhoods. Subtransmission circuits are usually arranged in loops so that a single line failure does not cut off service to a large number of customers for more than a short time. While subtransmission circuits are usually carried on overhead lines, in urban areas buried cable may be used.

There is no fixed cutoff between subtransmission and transmission, or subtransmission and distribution. The voltage ranges overlap somewhat. Voltages of 69 kV, 115 kV and 138 kV are often used for subtransmission in North America. As power systems evolved, voltages formerly used for transmission were used for subtransmission, and subtransmission voltages became distribution voltages. Like transmission, subtransmission moves relatively large amonts of power, and like distribution, subtransmission covers an area instead of just point to point. [12]
[edit] Transmission grid exit

At the substations, transformers reduce the voltage to a lower level for distribution to commercial and residential users. This distribution is accomplished with a combination of sub-transmission (33 kV to 132 kV) and distribution (3.3 to 25 kV). Finally, at the point of use, the energy is transformed to low voltage (varying by country and customer requirements—see mains power systems).
[edit] High-voltage direct current
Main article: High-voltage direct current

High voltage direct current (HVDC) is used to transmit large amounts of power over long distances or for interconnections between asynchronous grids. When electrical energy is required to be transmitted over very long distances, it is more economical to transmit using direct current instead of alternating current. For a long transmission line, the lower losses and reduced construction cost of a DC line can offset the additional cost of converter stations at each end. Also, at high AC voltages, significant (although economically acceptable) amounts of energy are lost due to corona discharge, the capacitance between phases or, in the case of buried cables, between phases and the soil or water in which the cable is buried.

HVDC is also used for long submarine cables because over about 30 km length AC can no longer be applied. In that case special high voltage cables for DC are built. Many submarine cable connections - up to 600 km length - are in use nowadays.

HVDC links are sometimes used to stabilize against control problems with the AC electricity flow. The power transmitted by an AC line increases as the phase angle between source end voltage and destination ends increases, but too great a phase angle will allow the generators at either end of the line to fall out of step. Since the power flow in a DC link is controlled independently of the phases of the AC networks at either end of the link, this stability limit does not apply to a DC line, and it can transfer its full thermal rating. A DC link stabilizes the AC grids at either end, since power flow and phase angle can be controlled independently.

In other words, to transmit AC power as AC when needed in either direction between Seattle and Boston would require the (highly challenging) continuous real-time adjustment of the relative phase of the two electrical grids. With HVDC instead the interconnection would: (1) Convert AC in Seattle into HVDC. (2) Use HVDC for the three thousand miles of cross country transmission. Then (3) convert the HVDC to locally synchronized AC in Boston, and optionally in other cooperating cities along the transmission route. One prominent example of such a transmission line is the Pacific DC Intertie located in the Western United States.
[edit] Limitations

The amount of power that can be sent over a transmission line is limited. The origins of the limits vary depending on the length of the line. For a short line, the heating of conductors due to line losses sets a thermal limit. If too much current is drawn, conductors may sag too close to the ground, or conductors and equipment may be damaged by overheating. For intermediate-length lines on the order of 100 km (62 mi), the limit is set by the voltage drop in the line. For longer AC lines, system stability sets the limit to the power that can be transferred. Approximately, the power flowing over an AC line is proportional to the sine of the phase angle of the voltage at the receiving and transmitting ends. Since this angle varies depending on system loading and generation, it is undesirable for the angle to approach 90 degrees. Very approximately, the allowable product of line length and maximum load is proportional to the square of the system voltage. Series capacitors or phase-shifting transformers are used on long lines to improve stability. High-voltage direct current lines are restricted only by thermal and voltage drop limits, since the phase angle is not material to their operation.

Up to now, it has been almost impossible to foresee the temperature distribution along the cable route, so that the maximum applicable current load was usually set as a compromise between understanding of operation conditions and risk minimization. The availability of industrial Distributed Temperature Sensing (DTS) systems that measure in real time temperatures all along the cable is a first step in monitoring the transmission system capacity. This monitoring solution is based on using passive optical fibers as temperature sensors, either integrated directly inside a high voltage cable or mounted externally on the cable insulation. A solution for overhead lines is also available. In this case the optical fiber is integrated into the core of a phase wire of overhead transmission lines (OPPC). The integrated Dynamic Cable Rating (DCR) or also called Real Time Thermal Rating (RTTR) solution enables not only to continuously monitor the temperature of a high voltage cable circuit in real time, but to safely utilize the existing network capacity to its maximum. Furthermore it provides the ability to the operator to predict the behavior of the transmission system upon major changes made to its initial operating conditions.
[edit] Control

To ensure safe and predictable operation the components of the transmission system are controlled with generators, switches, circuit breakers and loads. The voltage, power, frequency, load factor, and reliability capabilities of the transmission system are designed to provide cost effective performance for the customers.
[edit] Load balancing

The transmission system provides for base load and peak load capability, with safety and fault tolerance margins. The peak load times vary by region largely due to the industry mix. In very hot and very cold climates home air conditioning and heating loads have an effect on the overall load. They are typically highest in the late afternoon in the hottest part of the year and in mid-mornings and mid-evenings in the coldest part of the year. This makes the power requirements vary by the season and the time of day. Distribution system designs always take the base load and the peak load into consideration.

The transmission system usually does not have a large buffering capability to match the loads with the generation. Thus generation has to be kept matched to the load, to prevent overloading failures of the generation equipment.

Multiple sources and loads can be connected to the transmission system and they must be controlled to provide orderly transfer of power. In centralized power generation, only local control of generation is necessary, and it involves synchronization of the generation units, to prevent large transients and overload conditions.

In distributed power generation the generators are geographically distributed and the process to bring them online and offline must be carefully controlled. The load control signals can either be sent on separate lines or on the power lines themselves. To load balance the voltage and frequency can be used as a signaling mechanism.

In voltage signaling, the variation of voltage is used to increase generation. The power added by any system increases as the line voltage decreases. This arrangement is stable in principle. Voltage based regulation is complex to use in mesh networks, since the individual components and setpoints would need to be reconfigured every time a new generator is added to the mesh.

In frequency signaling, the generating units match the frequency of the power transmission system. In droop speed control, if the frequency decreases, the power is increased. (The drop in line frequency is an indication that the increased load is causing the generators to slow down.)

Wind turbines, v2g and other distributed storage and generation systems can be connected to the power grid, and interact with it to improve system operation.
[edit] Failure protection

Under excess load conditions, the system can be designed to fail gracefully rather than all at once. Brownouts occur when the supply power drops below the demand. Blackouts occur when the supply fails completely.

Rolling blackouts (also called load shedding) are intentionally engineered electrical power outages, used to distribute insufficient power when the demand for electricity exceeds the supply.
[edit] Communications

Operators of long transmission lines require reliable communications for control of the power grid and, often, associated generation and distribution facilities. Fault-sensing protective relays at each end of the line must communicate to monitor the flow of power into and out of the protected line section so that faulted conductors or equipment can be quickly de-energized and the balance of the system restored. Protection of the transmission line from short circuits and other faults is usually so critical that common carrier telecommunications are insufficiently reliable, and in remote areas a common carrier may not be available. Communication systems associated with a transmission project may use:

Microwaves
Power line communication
Optical fibers

Rarely, and for short distances, a utility will use pilot-wires strung along the transmission line path. Leased circuits from common carriers are not preferred since availability is not under control of the electric power transmission organization.

Transmission lines can also be used to carry data: this is called power-line carrier, or PLC. PLC signals can be easily received with a radio for the long wave range.

Optical fibers can be included in the stranded conductors of a transmission line, in the overhead shield wires. These cables are known as optical ground wire (OPGW). Sometimes a standalone cable is used, all-dielectric self-supporting (ADSS) cable, attached to the transmission line cross arms.

Some jurisdictions, such as Minnesota, prohibit energy transmission companies from selling surplus communication bandwidth or acting as a telecommunications common carrier. Where the regulatory structure permits, the utility can sell capacity in extra dark fibers to a common carrier, providing another revenue stream.
[edit] Electricity market reform
Main article: Electricity market

Some regulators regard electric transmission to be a natural monopoly[13][14] and there are moves in many countries to separately regulate transmission (see electricity market).

Spain was the first country to establish a regional transmission organization. In that country transmission operations and market operations are controlled by separate companies. The transmission system operator is Red Eléctrica de España (REE) and the wholesale electricity market operator is Operador del Mercado Ibérico de Energía - Polo Español, S.A. (OMEL) [2]. Spain's transmission system is interconnected with those of France, Portugal, and Morocco.

In the United States and parts of Canada, electrical transmission companies operate independently of generation and distribution companies.
[edit] Cost of electric power transmission

The cost of high voltage electricity transmission (as opposed to the costs of electricity distribution) is comparatively low, compared to all other costs arising in a consumer's electricity bill. In the UK transmission costs are about 0.2p/kWh compared to a delivered domestic price of around 10 p/kWh.[15]

Research evaluates the level of capital expenditure in the electric power T&D equipment market will be worth $128.9bn in 2011. [16]
[edit] Merchant transmission

Merchant transmission is an arrangement where a third party constructs and operates electric transmission lines through the franchise area of an unrelated utility. Advocates of merchant transmission[who?] claim that this will create competition to construct the most efficient and lowest cost additions to the transmission grid. Merchant transmission projects typically involve DC lines because it is easier to limit flows to paying customers.

Operating merchant transmission projects in the United States include the Cross Sound Cable from Long Island, New York to New Haven, Connecticut, Neptune RTS Transmission Line from Sayreville, N.J., to Newbridge, N.Y, ITC Holdings, Inc. transmission system in the midwest, and Path 15 in California. Additional projects are in development or have been proposed throughout the United States.

There is only one unregulated or market interconnector in Australia: Basslink between Tasmania and Victoria. Two DC links originally implemented as market interconnectors Directlink and Murraylink have been converted to regulated interconnectors. NEMMCO

A major barrier to wider adoption of merchant transmission is the difficulty in identifying who benefits from the facility so that the beneficiaries will pay the toll. Also, it is difficult for a merchant transmission line to compete when the alternative transmission lines are subsidized by other utility businesses.[17]
[edit] Health concerns
Main article: Electromagnetic radiation and health

The preponderance of evidence does not suggest that the low-power, low-frequency, electromagnetic radiation associated with household current constitutes a short or long term health hazard. Some studies have found statistical correlations between various diseases and living or working near power lines, but no adverse health effects have been substantiated for people not living close to powerlines.[18]

There are established biological effects for acute high level exposure to magnetic fields well above 100 µT. In a residential setting, there is "limited evidence of carcinogenicity in humans and less than sufficient evidence for carcinogenicity in experimental animals", in particular, childhood leukaemia, associated with average exposure to residential power-frequency magnetic field above 0.3 to 0.4 µT. These levels exceed average residential power-frequency magnetic fields in homes which are about 0.07 µT in Europe and 0.11 µT in North America.[19][20]
[edit] Government policy

Historically, local governments have exercised authority over the grid and have significant disincentives to take action that would benefit states other than their own. Localities with cheap electricity have a disincentive to making interstate commerce in electricity trading easier, since other regions will be able to compete for local energy and drive up rates. Some regulators in Maine for example do not wish to address congestion problems because the congestion serves to keep Maine rates low.[21] Further, vocal local constituencies can block or slow permitting by pointing to visual impact, environmental, and perceived health concerns. In the US, generation is growing 4 times faster than transmission, but big transmission upgrades require the coordination of multiple states, a multitude of interlocking permits, and cooperation between a significant portion of the 500 companies that own the grid. From a policy perspective, the control of the grid is balkanized, and even former energy secretary Bill Richardson refers to it as a third world grid. There have been efforts in the EU and US to confront the problem. The US national security interest in significantly growing transmission capacity drove passage of the 2005 energy act giving the Department of Energy the authority to approve transmission if states refuse to act. However, soon after using its power to designate two National Interest Electric Transmission Corridors, 14 senators signed a letter stating the DOE was being too aggressive.[22]
[edit] Special transmission
[edit] Grids for railways
Main article: Traction power network

In some countries where electric trains run on low frequency AC (e.g., 16.7 Hz and 25 Hz) power, there are separate single phase traction power networks operated by the railways. These grids are fed by separate generators in some traction powerstations or by traction current converter plants from the public three phase AC network.
[edit] Superconducting cables

High-temperature superconductors promise to revolutionize power distribution by providing lossless transmission of electrical power. The development of superconductors with transition temperatures higher than the boiling point of liquid nitrogen has made the concept of superconducting power lines commercially feasible, at least for high-load applications.[23] It has been estimated that the waste would be halved using this method, since the necessary refrigeration equipment would consume about half the power saved by the elimination of the majority of resistive losses. Some companies such as Consolidated Edison and American Superconductor have already begun commercial production of such systems.[24] In one hypothetical future system called a SuperGrid, the cost of cooling would be eliminated by coupling the transmission line with a liquid hydrogen pipeline.

Superconducting cables are particularly suited to high load density areas such as the business district of large cities, where purchase of an easement for cables would be very costly.[25]
[edit] Single wire earth return
Main article: Single-wire earth return

Single-wire earth return (SWER) or single wire ground return is a single-wire transmission line for supplying single-phase electrical power for an electrical grid to remote areas at low cost. It is principally used for rural electrification, but also finds use for larger isolated loads such as water pumps, and light rail. Single wire earth return is also used for HVDC over submarine power cables.
[edit] Wireless power transmission
Main article: Wireless energy transfer

Both Nikola Tesla and Hidetsugu Yagi attempted to devise systems for large scale wireless power transmission, with no commercial success.

Wireless power transmission has been studied for transmission of power from solar power satellites to the earth. A high power array of microwave transmitters would beam power to a rectenna. Major engineering and economic challenges face any solar power satellite project.
[edit] Security of control systems

The Federal government of the United States admits that the power grid is susceptible to cyber-warfare.[26][27] The United States Department of Homeland Security works with industry to identify vulnerabilities and to help industry enhance the security of control system networks, the federal government is also working to ensure that security is built in as the U.S. develops the next generation of 'smart grid' networks.[28]
[edit] Records

Highest capacity system: 6.3 GW HVDC Itaipu (Brazil) (±600 kV DC)[29]
Highest transmission voltage (AC): 1.15 MV on Powerline Ekibastuz-Kokshetau (Kazakhstan)
Largest double-circuit transmission, Kita-Iwaki Powerline.
Highest pylons: Yangtze River Crossing (height: 345 m/1,132 ft)
Longest power line: Inga-Shaba (length: 1,700 kilometres / 1,056 miles)
Longest span of power line: 5,376 m (17,638 ft) at Ameralik Span
Longest submarine cables:
NorNed, North Sea - (length of submarine cable: 580 kilometres / 360 miles)
Basslink, Bass Strait - (length of submarine cable: 290 kilometres / 180 miles, total length: 370.1 kilometres / 230 miles)
Baltic-Cable, Baltic Sea - (length of submarine cable: 238 kilometres / 148 miles, HVDC length: 250 kilometres / 155 miles, total length: 262 kilometres / 163 miles)
Longest underground cables:
Murraylink, Riverland/Sunraysia - (length of underground cable: 180 kilometres / 112 miles)

[edit] See also
Crystal energy.svg Energy portal

Conductor marking lights
Dynamic demand (electric power)
Demand response
Distributed generation
Double-circuit transmission line
Electricity distribution
Electricity market
Electricity pylon
Electromagnetic Transients Program (EMTP)
Flexible AC transmission system (FACTS)
Geomagnetically induced current, (GIC)
Green power grid
Grid-tied electrical system
High-voltage direct current (HVDC)
Infrastructure
List of high voltage underground and submarine cables
Load profile

Mains electricity
Mains power around the world (list of voltage by country)
Miesbach-Munich Power Transmission
Off-the-grid, living without public utility
Overhead power line
Power line communications (PLC)
Power System Harmonics
Power outage
Radio frequency power transmission
Relative cost of electricity generated by different sources
Submarine power cable
Traction current
Traction power network
Three-phase electric power
V2G
Wheeling (electric power transmission)
Wireless energy transfer
25Hz Power Transmission System

[edit] Notes

^ (pdf) A Primer on Electric Utilities, Deregulation, and Restructuring of U.S. Electricity Markets. United States Department of Energy Federal Energy Management Program (FEMP). 2002-05. Retrieved December 27, 2008.
^ Hans Dieter Betz, Ulrich Schumann, Pierre Laroche (2009). Lightning: Principles, Instruments and Applications. Springer, pp. 202-203. ISBN 9781402090783. Retrieved on May 13, 2009.
^ a b c Thomas P. Hughes (1993). Networks of Power: Electrification in Western Society, 1880-1930. Baltimore: Johns Hopkins University Press. pp. 119–122. ISBN 0801846145.
^ National Council on Electricity Policy (pdf). Electricity Transmission: A primer.
^ Bureau of Census data reprinted in Hughes, pp. 282-283
^ Hughes, pp. 293-295
^ "Present Limits of Very Long Distance Transmission Systems"
^ Hutchingson, Alex. "The New Energy Fixes: 10 Fixes." Popular Mechanics. June 2011: 73. Print.
^ California Public Utilities Commission Corona and induced currents
^ a b "Where can I find data on electricity transmission and distribution losses?". Frequently Asked Questions – Electricity. U.S. Energy Information Administration. 2009-11-19. Retrieved 2011-03-29.
^ L. Paris et al. (1984). "Present Limits of Very Long Distance Transmission Systems". CIGRE. Global Energy Network Institute. Retrieved 2011-03-29.
^ Donald G. Fink and H. Wayne Beaty, Standard Handbook for Electrical Engineers (15th Edition) McGraw-Hill, 2007 ISBN 978-0-07-144146-9 section 18.5
^ Raghuvir Srinivasan (August 15, 2004). "Power transmission business is a natural monopoly". The Hindu Business Line. The Hindu. Retrieved January 31, 2008.
^ Lynne Kiesling (August 18, 2003). "Rethink the Natural Monopoly Justification of Electricity Regulation". Reason Foundation. Retrieved January 31, 2008.
^ http://www.claverton-energy.com/what-is-the-cost-per-kwh-of-bulk-transmission-national-grid-in-the-uk-note-this-excludes-distribution-costs.html What is the cost per kWh of bulk transmission / National Grid in the UK (note this excludes distribution costs)
^ visiongain The Electric Power Transmission & Distribution (T&D) Equipment Market 2011-2021 http://www.visiongain.com/Report/626/The-Electric-Power-Transmission-and-Distribution-(T-D)-Equipment-Market-2011-2021
^ Fiona Woolf (February 2003). Global Transmission Expansion. Pennwell Books. pp. 226, 247. ISBN 0-87814-862-0.
^ Electromagnetic fields and public health, World Health Organization
^ "Electromagnetic fields and public health". Fact sheet No. 322. World Health Organization. June 2007. Retrieved 2008-01-23.
^ "Electric and Magnetic Fields Associated with the Use of Power" (PDF). National Institute of Environmental Health Sciences. 2002-06. Retrieved 2008-01-29.
^ National Council on Electricity Policy (pdf). Electricity Transmission: A primer. p. 32 (41 in pdf).
^ Wald, Matthew (August 27, 2008). Wind Energy Bumps Into Power Grid's Limits. New York Times. p. A1. Retrieved December 12, 2008.
^ Jacob Oestergaard et al., Energy losses of superconducting power transmission cables in the grid, [1]
^ 600m superconducting electricity line layed in New York
^ http://www.futureenergies.com/print.php?sid=237
^ BBC: Spies 'infiltrate US power grid'
^ CNN: Video
^ Reuters: US concerned power grid vulnerable to cyber-attack
^ "Energy Systems, Environment and Development". Advanced Technology Assessment Systems (Global Energy Network Institute) (6). Autumn 1991. Retrieved December 27, 2008.

[edit] Further reading

Grigsby, L. L., et al. The Electric Power Engineering Handbook. USA: CRC Press. (2001). ISBN 0-8493-8578-4
Thomas P. Hughes, Networks of Power: Electrification in Western Society 1880-1930, The Johns Hopkins University Press,Baltimore 1983 ISBN 0-8018-2873-2, an excellent overview of development during the first 50 years of commercial electric power
Reilly, Helen (2008). Connecting the Country – New Zealand’s National Grid 1886 - 2007. Wellington: Steele Roberts. pp. 376 pages.. ISBN 978-1-877448-40-9.
Westinghouse Electric Corporation, "Electric power transmission patents; Tesla polyphase system". (Transmission of power; polyphase system; Tesla patents)
Pansini, Anthony J, E.E., P.E. undergrounding electric lines. USA Hayden Book Co, 1978. ISBN 0-8104-0827-9

[edit] External links
Look up grid electricity in Wiktionary, the free dictionary.

Japan: World's First In-Grid High-Temperature Superconducting Power Cable System
A Power Grid for the Hydrogen Economy: Overview/A Continental SuperGrid
Global Energy Network Institute (GENI) - The GENI Initiative focuses on linking renewable energy resources around the world using international electricity transmission.
Union for the Co-ordination of Transmission of Electricity (UCTE), the association of transmission system operators in continental Europe, running one of the two largest power transmission systems in the world
Non-Ionizing Radiation, Part 1: Static and Extremely Low-Frequency (ELF) Electric and Magnetic Fields (2002) by the IARC -- Link Broken.
A Simulation of the Power Grid - The Trustworthy Cyber Infrastructure for the Power Grid (TCIP) group at the University of Illinois at Urbana-Champaign has developed lessons and an applet which illustrate the transmission of electricity from generators to energy consumers, and allows the user to manipulate generation, consumption, and power flow.

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