The next great telecom revolution phần 10

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206 THE CRITICAL LAST INCH—INPUT AND OUTPUT TECHNOLOGIES materials, LEPs are able to reduce manufacturing cost through effective material utilization. “LEPs offer all the advantages of small-molecule technology such as lowpower consumption and low-drive voltages,” says Joe Constance, an analyst at Technical Insights, a technology research company located in San Antonio, Texas. “LEP devices can generate sharp light output, or resolution, and can be fabricated cost effectively in high-pixel density configurations,” he adds. Efficient control over structural order in LEPs is required to have an edge over traditional liquid crystal displays. In this regard, polymers that have different band gaps may prove to be a key factor in outplaying competing technologies. Emission of red, green, or blue light is possible with different bands, making full-color displays with conductive LEPs commercially viable. Intense research in this area has enabled poly-phenylene vinylene (PPV) to emit blue light by interrupting conjugation in the polymer with nonconjugated units. Attachment of alkoxy side groups to the phenylene rings of the PPV enables red light production. A full-color polymer-based display requires pixellating the colors through the combination of different conducting polymers with varying band gaps. The color emitted from the blend will depend on the amount of voltage applied, which increases with the band gap. An alternative route would be to use whitelight-emitting diodes to create a microcavity, the length of which determines the color of the emitted light. Apart from varying band gaps, polymer-based light-emitting diodes also face the challenge of increasing operating lifetimes to at least 20,000 hours to popularize commercial usage. When the luminance intensity of the device decreases to 70 percent of the original value, it is considered the actual end of life as opposed to 50 percent referenced for display applications. “In the area of LEPs, significant research has been in progress to improve material lifetimes both through the use of materials that are resistant to oxidation and through improved encapsulation,” explains Constance. Conducting polymers based on doped polyaniline, conjugated polymer material, and polypyrrole are already demonstrating the stability required for commercial applications, proving the potential for growth and wider acceptance in the future. Researchers at the Xerox Research Center of Canada recently announced a new polymer in the polythiophene family. This polymer has the best electrical properties of any reported plastic semiconductor. Scientists at Xerox’s Palo Alto Research Center (PARC) succeeded in jet-printing this material and other polymer semiconductors to make transistors. The jet-printed transistors made this way have matched the performance of the same material deposited by conventional spin-coating (which gives an unpatterned film), showing that the jet-printing process does not adversely affect the performance of the device. The transistors have exceptional performance for polymers and meet all the requirements for addressing displays. Along with a high mobility, they have very low leakage and good stability. PAPER-LIKE VIDEO DISPLAYS 207 There is much more involved in the fabrication of a low-cost transistor array than just printing the polymer semiconductor. As with any integrated electronic device, metals and insulators must also be deposited and patterned into a multi-layer structure having the right electronic circuit and an appropriate physical size. The PARC scientists have successfully integrated the jet-printed polymer into a prototype display circuit, in which printing techniques define all the patterns. The electronic properties and physical dimensions meet the needs of flat-panel displays, and the complete absence of photolithography promises low-cost manufacture. The PARC array design also solves key issues of unwanted interactions between pixels of the display, accurate layer-to-layer alignment, and materials compatibility. Although much more development is needed to make the jet-printed organic semiconductor display process ready for manufacture, this breakthrough demonstration at PARC represents proof that it can be done successfully. 9.9.4 Quantum Displays Massachusetts Institute of Technology (MIT) researchers have developed a new display technology that promises to someday replace conventional LCDs. The technology—a quantum dot-organic light-emitting device (QD-OLED)— allows the creation of flat-panel screens that consume less power and produce better images than existing counterparts. Based on high-performing inorganic nanocrystals—combined with organic materials—QD-OLEDs would be ideal for use in mobile devices. Unlike traditional LCDs, which must be lit from behind, quantum dots generate their own light. Depending on their size, the dots can be “tuned” to emit any color in the rainbow. Better yet, the colors they produce are highly saturated, permitting richer, more lifelike images. Also known as “artificial atoms,” quantum dots are nanometer-scale “boxes” that selectively hold or release electrons. The latest MIT QD-OLED contains only a single layer of quantum dots sandwiched between two organic thin films. Previous QD-OLEDs used anywhere from 10 to 20 film layers. The researchers have created QD-OLEDs over a 1-cm2 area, although the same principle could be used to make larger components. The MIT team’s method of combining organic and inorganic materials could also pave the way for new technologies and enhance understanding of the physics of these materials. Besides allowing the creation of extraordinarily thin, bright flat-panel displays, the QD-OLEDs may also be used to calibrate wavelengths for scientific purposes, generate wavelengths visible only to robot eyes or to “miniaturize scientific equipment in ways we haven’t yet imagined,” says Moungi Bawendi, an MIT chemistry professor. The QD-OLEDs created in the study have a 25-fold improvement in luminescent power efficiency over previous QD-OLEDs. The researchers note that in time the devices may be made even more efficient and be able to achieve 208 THE CRITICAL LAST INCH—INPUT AND OUTPUT TECHNOLOGIES even higher color saturation. “One of the goals is to demonstrate a display that is stable, simple to produce, flat, high-resolution and that uses minimal power,” says Vladimir Bulovic, an assistant professor of electrical engineering and computer science at MIT. The MIT researchers were inspired by advances in completely OLED technology. OLEDs, which can be used to create TVs or computer screens only a fraction of an inch thick with the same brightness as LCDs, are now making their way into commercial electronic devices. The MIT group envisions that QD-OLEDs will in time become complementary to OLEDs because they can be built on the same electronic platforms with compatible manufacturing methods. The QD-OLED research is funded by the National Science Foundation and Universal Display Corp., an OLED technology developer located in Ewing, New Jersey. 9.10 FINDING INFORMATION Given their imperfect input/output technologies, finding information on tiny devices can be highly problematic. Researchers, however, are working on technologies that promise to make finding hard-to-access information a snap. Researchers at the University of Southern California (USC), for instance, have created a new tool for organizing and visualizing collections of electronic mail.The system is designed to help legal researchers, historians, and archivists, as well as ordinary business people, deal with large e-mail archives. Developed by Anton Leuski, a researcher at the USC School of Engineering’s Information Sciences Institute, the eArchivarius system uses sophisticated search software developed for Internet search engines like Google to detect important relationships between messages and people. The technology takes advantage of inherent clues that exist in e-mail collections and then automatically creates a vivid and intuitive visual interface that uses spheres grouped in space to represent relationships. In an experimental exercise, USC researchers collected e-mail exchanges conducted between Reagan administration national security officials.The visualization showed some e-mail recipients closely packed toward the display’s center and their most frequent correspondents bunched into a tight cluster. Less frequent correspondents were literally out of the loop, with their spheres located far out on the display’s periphery. Besides correspondence activity, spheres representing people can also be arranged under other criteria, such as the content of the authored messages. The display configuration would then show communities of people who converse on the same topic and the relationships among those communities. With the eArchivarius system, selecting any e-mail recipient opens a new window, which provides a list of all the people with whom the selected person exchanged correspondence. A time-graphed record also shows when the FINDING INFORMATION 209 exchanges took place. “For a historian trying to understand the process by which a decision was made over a course of months, this kind of access will be extremely valuable,” says Leuski. The same interface can instantly return and display individual pieces of mail in the form of hypertext pages, with links to the people who sent and received the e-mail and with links to similar e-mail messages. “Similar messages” can be defined in terms of recipients, text keywords, or both. In a display produced using this capability, the spheres are the messages themselves. With message-oriented spheres, different colors indicate different topics, creating a map of how the information is distributed among the messages. “What we have in effect is a four-dimensional display, with color added to the three spatial dimensions,” says Douglas Oard, an associate professor of computer science from University of Maryland’s College of Information Studies and its Institute for Advanced Computer Studies. Leuski and Oard have demonstrated the ability to find interesting patterns in collections as small as a few hundred e-mails. The techniques they have developed are now being applied to thousands of e-mails sent and received by a single individual over 18 years. Scaling the system upward to process millions of e-mails involving thousands of people will be the researchers’ next challenge. The elements of eArchivarius’ flexible and useful interface, says Oard, may someday find their way into everyday e-mail client software. 9.10.1 Simplified Image Retrieval Penn State University has developed software that allows computer users to search for images more easily and accurately by eliminating the need to enter lengthy descriptive phrases. The technology could potentially help mobile device users who currently must deal with cramped displays as well as people who must routinely catalogue or access large numbers of images. The Automatic Linguistic Indexing of Pictures (ALIP) system builds a pictorial dictionary and then uses it to associate images with keywords. The technology functions like a human expert who annotates or classifies terms. “While the prototype is in its infancy, it has demonstrated great potential for use in biomedicine by reading x-rays and CT scans, as well as in digital libraries, business, Web searches and the military,” says Dr. James Z. Wang, an assistant professor at Penn State’s School of Information Sciences and Technology and the project’s lead researcher. Unlike other content-based retrieval systems that compare features of visually similar images, ALIP uses verbal cues that range from simple concepts such as “flowers” and “mushrooms” to higher-level terms such as “rural” and “European.” ALIP can also classify images into a larger number of categories than other systems, thereby broadening the uses of image databases. ALIP processes images the way people do. When someone sees a new kind of vehicle with two wheels—a seat and a handlebar, for example—it’s recog- 210 THE CRITICAL LAST INCH—INPUT AND OUTPUT TECHNOLOGIES nized as a bicycle from information about related images stored in the brain. ALIP has a similar bank of statistical models that “learn” from analyzing specific image features. Other advantages include ALIP’s ability to be trained with a relatively large number of concepts simultaneously and with images that are not necessarily visually similar. In one experiment, researchers trained ALIP with 24,000 photographs found on 600 CD-ROMs, with each CD-ROM collection assigned keywords to describe its content. After “learning” these images, the computer then automatically created a dictionary of concepts such as “building,” “landscape,” and “European.” Statistical modeling enabled ALIP to automatically index new or unlearned images with the dictionary’s linguistic terms. Future research will be aimed at improving ALIP’s accuracy and speed. ALIP’s reading of a beach scene with sailboats yielded the keyword annotations of “ocean,” “paradise,” “San Diego,” “Thailand,” “beach” and “fish.” Although the computer was intelligent enough to recognize the high-level concept of “paradise,” additional research will focus on making the technology more accurate, so that San Diego and Thailand will not appear in the annotation of the same picture, Wang says. “This system has the potential to change how we handle images in our daily life by giving us better and more access,” says Wang. 9.11 DISABLED ACCESS Disabled individuals are typically forgotten in discussions about input/output technologies. Mobile phones, for instance, are still a work in progress with regard to meeting the needs of individuals with disabilities, who are missing out on wireless communication opportunities because of usability problems. 9.11.1 Mobile Phone Interface Virginia Tech’s Tonya Smith-Jackson, assistant professor, and Maury Nussbaum, associate professor, both in the Grado Department of Industrial and Systems Engineering, are conducting research to improve the cell phone interface for users with disabilities. The Telecommunications Act of 1996 placed the demand on manufacturers of mobile phones to support accessibility for individuals with physical, visual, or cognitive disabilities. “Users with disabilities have been systematically marginalized in the information age because manufacturers and designers have either ignored their needs altogether or designed features in a haphazard manner that were intended to enhance accessibility, yet resulted in unusable products,” says Smith-Jackson. While trying to operate a mobile phone, users with disabilities typically encounter problems such as small and flat buttons that are difficult to push with bent fingers, keypads with no Braille or tactile feedback to assist with ori- DISABLED ACCESS 211 entation, or lack of voice activation capabilities. Sometimes, special features are available for disabled customers, but the features do not perform consistently, such as voice-activated phones failing to work in a noisy environment. People who have more than one type of disability have even greater difficulty operating mobile phones. The first goal of this research is to identify user requirements and challenges related to user interface designs of cell phones. The second research goal is to conduct usability tests with existing interfaces of selected Toshiba phones designed for the Japanese domestic market that will be marketed in the United States. As part of the study for Toshiba, the researchers and their graduate students are using product interactive focus groups and usability testing to target the needs of users with the following disabilities: legal blindness, cognitive disabilities, full blindness, and upper extremity physical disabilities. Information from these interviews is being used to extract design guidelines to enhance cell phone accessibility and to develop new features for future cell phone interfaces. 9.11.2 GPS Guidance Telecom technologies, when equipped with special interfaces, can also help disabled people cope better with the real world. A new GPS-based navigation developed by ONCE, the Organization of Spanish Blind people, is designed to guide blind people. The system, called “Tormes,” is a handheld computer with a Braille keyboard and satellite navigation technology that gives verbal directions. Tormes can be used in two ways: to guide the user to their destination or to tell them where they are as they walk around. Tormes is currently limited by GPS’s 15 to 20 meter accuracy. But ONCE and the European Space Agency are already working on how to improve the system. A new tool developed •• by ESA could be the breakthrough: the European Geostationary Navigation Overlay Service (EGNOS). It also warns the users of any problem with the signal thus giving integrity information. EGNOS is transmitted to the ground via geostationary satellites, so signals are sometimes blocked by buildings, called the canyon effect. To solve this problem, ESA engineers had the idea of getting the data through the Internet via a GSM connection, a project called SISNeT (Signal In Space through Internet). This makes EGNOS available anywhere downtown. As a result, blind people accessing information via Tormes will be able to distinguish individual streets as they approach them. Ruben Dominguez, a blind mathematician who has tried out the device, says, “This completes what exists for assisting blind people: the dog or the white cane, but furthermore it will really improve the life of the blind community by giving a lot more autonomy when moving around town, especially in unknown places.” EGNOS is scheduled to become operational by 2005. 212 9.11.3 THE CRITICAL LAST INCH—INPUT AND OUTPUT TECHNOLOGIES Speech-Controlled Arm Using two motors, speech-recognition software, and an exoskeleton inspired by science fiction, three Johns Hopkins University undergraduates have designed and built a muscle-enhancement device specifically for a disabled person that will help him lift a cup, a book, and other household items. By uttering commands such as “open” and “raise,” this user will receive mechanical help in moving his fingers and bending his elbow. The motorized plastic shell will fit over the right arm of the man, who has an extremely rare degenerative muscle disorder called inclusion body myositis. This device, which could be adapted for other people with disabilities, was developed by students in the Department of Mechanical Engineering’s Senior Design Project course. The project originated when the man with the muscle disease sought help from Volunteers for Medical Engineering, a nonprofit Baltimore group that uses technology to assist people with disabilities. The client explained that his nerves were intact, meaning that he could control the placement of his fingers around an object. But progressive muscle deterioration left him unable to grasp and lift even small objects. To help him, the Volunteers for Medical Engineering sponsored a project in the Johns Hopkins course. The task of designing and building the device went to a team consisting of three senior students: Jonathan Hofeller, a mechanical engineering student; Christina Peace, a biomedical engineering student; and Nathaniel Young; a biomedical engineering student. The students researched prosthetic limbs, and, taking a cue from props featured in the film “Aliens,” they designed a plastic exoskeleton that could slide over the client’s right hand and arm. To help move his fingers and elbow, the students tested and rejected systems using electromagnets and air pressure systems. They finally settled on two small but powerful stepper motors. These could move the fingers and elbow in small, slow increments, allowing the client to clasp a cup firmly without crushing it. In addition, these motors did not require continuous electrical current to stay in position, which preserves battery power. The students linked the motors to a series of cables and springs to enable the device to move the man’s arm into position and help his fingers grasp and release. The students opted for voice recognition software as an easy way for the disabled man to control the grasping device. After the software is trained to the client’s voice, the man will first say “arm” or “hand” to take command of one of the two motors. The elbow motor will then respond to “raise,” “down,” or “stop.” The hand motor will respond to “open,” close,” and “stop.” The device is hard-wired to a control box that contains a miniature computer and two programs that turn the voice commands into signals that tell the motors how to operate the bending and grasping motions. The unit is powered by a rechargeable 12-volt lead-acid battery commonly used for remote-control model boats and airplanes. The control box fits inside a small pack that the man can carry on his waist, making the grasping the device fully portable. DISABLED ACCESS 213 “[The students] came up with a very creative design for the device,” says Jan Hoffberger, executive director of Volunteers for Medical Engineering. “They purposely set it up to move very slowly, so that at any time in the grasping and lifting process, our client can tell it to stop. We believe he will find it very helpful.” The students had to work within a budget of $10,000; they ended up spending about $8,000 on the device. Designing and building it helped the undergraduates to understand some of the challenges that working engineers face. “In a textbook, there is always one right answer,” says Young. “In this project, there were many different ways we could go, but once we were committed we had to go in that direction.” His teammate, Hofeller, says, “The project involved a lot of trial and error, but it was fun to apply what we’ve been learning.” The third team member, Peace, added, “When you’re working out a problem in an engineering book, the conditions are ideal. In this project, the conditions were not perfect, but we still got the job done.” Glossary 1G: – See First-generation services. 2G: – See Second-generation services. 3G: – See Third-generation services. 4G: – See Fourth-generation services. 802.11x: – A series of IEEE standards for wireless LANs, including 80211.a, 80211.b, and numerous others. Algorithm: – A step-by-step mathematical procedure for solving a problem. Anechoic: – Free from echoes and reverberations. Asset tracking: – Technology that is used to follow the physical movements of objects and people. Baby Bell: – One of the original Bell System operating companies. Bandgap: – The energy difference in a material between its nonconductive state and its conductive state. Bell System: – Refers to AT&T and its Bell operating companies, which dominated the U.S. telephone industry until a court-ordered breakup in 1984. Bit: – The smallest element of computer information. Bits per second (bps): – A data network speed measurement. A 10-Mbps, network, for example, has a top data transfer speed of 10 million bits per second. Telecosmos: The Next Great Telecom Revolution, edited by John Edwards ISBN 0-471-65533-3 Copyright © 2005 by John Wiley & Sons, Inc. 214 GLOSSARY 215 Blackberry: – A line of wireless e-mail devices produced by Research In Motion. Bluetooth: – An open standard for the short-range transmission of digital voice and data between mobile devices. BPL: – See Broadband over power lines. bps: – See Bits per second. Broadband: – High-speed Internet access, faster than 56K bps dial-up service. Broadband over power lines (BPL): – An Internet access technology that use poker lines. Buckyball: – A spherical carbon molecule, also known as a “Fullerine,” composed of 60 atoms. Buckyballs are lighter than plastic and stronger than steel. Cable modem: – A device that connects a computer to a cable television system’s broadband Internet service. Carrier: – A telecommunications service provider. Cathode ray tube (CRT): – A vacuum tube that serves as a computer display. CDMA: – See Code division multiple access. CDMA 2000: – See Code division multiple access 2000. CLEC: – See Competitive local exchange carrier. Code division multiple access (CDMA): – A second-generation (2G) digital mobile phone technology that operates in the 800-MHz and 1.9-GHz PCS bands. Code division multiple access 2000 (CDMA 2000): – A CDMA version for third-generation (3G) networks. Competitive local exchange carrier (CLEC): – A local telephone carrier that was not one of the original Bell System operating companies. Constellation: – An array of satellites that is designed to provide continuous, or near-continuous, access from any point on earth. CRT: – See Cathode ray tube. Cybersecurity: – The protection of computers and networks. DARPA: – See Defense Advanced Research Projects Agency. Data hiding: – See Steganography. Defense Advanced Research Projects Agency (DARPA): – The central research and development organization for the U.S. Department of Defense (DoD). Dense wavelength division multiplexing (DWDM): – A higher capacity form of wavelength division multiplexing. Dielectric: – An insulator, such as glass or plastic. Digital radio: – A radio based on digital technology. Digital subscriber line (DSL): – High-speed Internet access service using phone lines.
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