| The Federal Communications Commission: Current Structure and Its Role in the Changing Telecommunications Landscape |
14-May-2009 |
15 pages |
| Authors:
Patricia M Figliola; LIBRARY OF CONGRESS WASHINGTON DC CONGRESSIONAL RESEARCH SERVICE
|
 | The Federal Communications Commission (FCC) is an independent Federal agency with its five members appointed by the President, subject to confirmation by the Senate. It was established by the Communications Act of 1934 (1934 Act) and is charged with regulating interstate and international communications by radio, television, wire, satellite, and cable. The mission of the FCC is to ensure that the American people have available -- at reasonable cost and ... |
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| Tethered Antennas for Unmanned Underwater Vehicles |
27-Apr-2009 |
40 pages |
| Authors:
Roger E Race; Jacob C Piskura; BROOKE OCEAN TECHNOLOGY USA NEW BEDFORD MA
|
| The Small Business Innovation Research (SBIR) Program has funded the development of a system that will allow UUVs to communicate through RF communication and collect GPS location while below the surface and travelling at speed. Under this effort, Brooke Ocean Technology USA, Inc. (BOT USA) has conducted a Phase I study to develop, evaluate, and select innovative concepts for a Towed Antenna System (TAS). Based on this study, a functional ... |
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| Surveying through Text Message: Planning, Programming, and Analyzing |
Apr-2009 |
33 pages |
| Authors:
Zannette A Uriell; Evangeline M Clewis; NAVY PERSONNEL RESEARCH STUDIES AND TECHNOLOGY MILLINGTON TN
|
| Surveys conducted through text messaging, or Short Message Service (SMS), are a relatively new phenomenon, since SMS text messaging has only existed since 1992. SMS surveys are even more recent for the military population, with the first known military-population SMS survey being conducted in 2008. This report provides the method used for the early SMS surveys, named Lightning Polls when conducted by NPRST, and includes suggestions on planning for an ... |
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| Use of Text Messaging by Navy Recruiters |
Apr-2009 |
81 pages |
| Authors:
Zannette A Uriell; Evangeline M Clewis; NAVY PERSONNEL RESEARCH STUDIES AND TECHNOLOGY MILLINGTON TN
|
| In Summer 2008, Navy recruiters were invited to participate in the first known survey conducted through cell phone text message. Recruiters received two text message questions, one about their use of text messaging for contacting potential applicants and a second about the usefulness of text messaging for staying in contact with those in the Delayed Entry Program (DEP). In addition, recruiters received a paper-based survey asking about their weekly use ... |
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| MIMO-UAC for Rate Enhancement and Range Extension |
Dec-2008 |
14 pages |
| Authors:
Jian Li; Liuqing Yang; FLORIDA UNIV GAINESVILLE DEPT OF ELECTRICAL AND COMPUTER ENGINEERING
|
| Our research focuses on the horizontal underwater acoustic communications. During this year, our research on multi-input multi-output underwater acoustic communications (MIMO-UAC) can be categorized into two thrusts: (1) Robust MIMO-UAC with Low-Complexity Receivers and (2) Enhanced Channel Estimation and Symbol Detection for High Speed MIMO-UAC. In terms of MIMO-UAC with low-complexity receivers, we have established a simple windowed least squares (LS) channel estimator, developed a differential MIMO scheme obviating channel ... |
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| Robustness and Survivability Issues in Wireless Ad Hoc Networks |
30-Nov-2008 |
17 pages |
| Authors:
Guoliang Xue; ARIZONA STATE UNIV TEMPE
|
| Significant contributions have been made in the course of this project. These results are published in 14 journal papers and 18 refereed conference papers. The journal papers appeared in prestigious journals such as IEEE/ACM Transactions on Networking, IEEE Transactions on Computers, IEEE Transactions on Wireless Communications, and IEEE Transactions on Vehicular Technology. The Conference papers appeared in IEEE INFOCOM (2005, 2006, 2007, 2008), ACM MobiHoc (2005), IEEE Military Communication Conference ... |
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| Livespace Technical Overview |
Oct-2008 |
70 pages |
| Authors:
Matthew Phillips; DEFENCE SCIENCE AND TECHNOLOGY ORGANISATION EDINBURGH (AUSTRALIA) COMMAND CONTROL COMMUNICATIONS AND INTELLIGENCE DIV
|
| This report describes Livespaces, a technology framework developed by DSTO to support advanced meeting spaces and distributed multi-site collaboration. It discusses the rationale behind the Livespace concept, the history of the research and development that led up to the Livespaces approach, and, in particular, its roots in providing support for the intense collaboration sessions often required by ADF operational planning specialists. The novel technical architecture employed by the Livespaces operating ... |
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| Statistical Modeling of Radiometric Error Propagation in Support of Hyperspectral Imaging Inversion and Optimized Ground Sensor Network Design |
04-Sep-2008 |
326 pages |
| Authors:
Scott Klempner; ROCHESTER INST OF TECH NY
|
| A method is presented that attempts to isolate the relative magnitudes of various error sources present in common algorithms for inverting the effects of atmospheric scattering and absorption on solar irradiance and determine in what ways, if any, operational ground truth measurement systems can be employed to reduce the overall error in retrieved reflectance factor. Error modeling and propagation methodology is developed for each link in the imaging chain, and ... |
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| Smart Caching for Efficient Information Sharing in Distributed Information Systems |
01-Sep-2008 |
67 pages |
| Authors:
Dirk Ableiter; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| Remarkable technical advances in cell phones and smart phones have resulted in a worldwide marketplace permeated by mobile devices. These capabilities, in combination with increasing consumers demand to share information show the need for utilizing the mobile devices more efficiently. But, within a distributed network of mobile devices like TwiddleNet, the two most limiting resources are still battery power and bandwidth. By distributing only small sets of data that represent ... |
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| Functional Requirements Study |
Jul-2008 |
52 pages |
| Authors:
G W Johnson; I M Gonin; L Alexander; B J Tetreault; ALION SCIENCES AND TECHNOLOGY NEW LONDON CT
|
| Automatic Identification System (AIS) is an autonomous broadcast that exchanges maritime safety/security information between participating vessels and shore stations. In addition to providing a means for maritime administrations to track the movement of vessels in coastal waters, AIS can be used to transmit information to ships while inport or underway to ensure safety-of-navigation and protection of the marine environment. In the USA, it is intended that this capability will enhance ... |
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| Development of a Night Vision Goggle Heads-Up Display for Paratrooper Guidance |
01-Jun-2008 |
140 pages |
| Authors:
AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH GRADUATE SCHOOL OF ENGINEERING AND MANAGEMENT
|
| This thesis provides the proof of concept for the development and implementation of a Global Positioning System (GPS) display via Night Vision Goggles (NVG) Heads-Up Display (HUD) for paratroopers. The system has been designed for soldiers who will be able to utilize the technology in the form of a processing system worn in an ammo pouch and displayed via NVG HUD as a tunnel in the sky. The tunnel in ... |
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| Multiple-User Quantum Information Theory for Optical Communication Channels |
Jun-2008 |
240 pages |
| Authors:
Saikat Guha; MASSACHUSETTS INST OF TECH CAMBRIDGE DEPT OF ELECTRICAL ENGINEERING AND COMPUTER SCIENCE
|
| Research has established capacity theorems for point-to-point bosonic channels with additive thermal noise, under the presumption of a conjecture on the minimum output von Neumann entropy. In the first part of this thesis, we evaluate the optimum capacity for free-space line-of-sight optical communication using Gaussian-attenuation apertures. Optimal power allocation across all the spatio-temporal modes is studied, in both the far-field and near-field propagation regimes. We establish the gap between ultimate ... |
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| Research and Demonstration of Video Streaming on Unmanned Aerial Vehicles (UAV) Networks |
01-May-2008 |
16 pages |
| Authors:
H T Kung; HARVARD UNIV CAMBRIDGE MA
|
| This project has led to a number of findings and conclusions. The main results concern the task of using one or more Unmanned Aerial Vehicles (UAVs) to relay messages or videos between two distant ground nodes. A protocol, called load-carry-and-deliver (LCAD), has been developed and implemented, where a UAV load from a source ground node, carries the data while flying to the destination, and finally delivers the data to a ... |
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| Evaluation of Head Mounted and Head Down Information Displays During Simulated Mine-Countermeasures Dives to 42 msw |
01-Apr-2008 |
57 pages |
| Authors:
J B Morrison; J K Zander; SHEARWATER HUMAN ENGINEERING NORTH VANCOUVER (BRITISH COLUMBIA)
|
| Despite recent advancements in diver communications, there is little information on the ability of divers to use a multi-function head down display (HDD) or head mounted display (HMD) for routine underwater tasks. Three information displays (HDD, and a monocular and binocular HMD) were tested by nine mine counter-measures (MCM) divers at the surface and during simulated dives to 42 metres in 6 deg C water. Divers used the displays to ... |
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| VoIP Softphones |
01-Apr-2008 |
5 pages |
| Authors:
David Premeaux; ARMY INFORMATION SYSTEMS ENGINEERING COMMAND FORT HUACHUCA AZ
|
| Voice over Internet Protocol (VoIP) provides the user with an opportunity to combine the use of a telephone with a personal computer (PC) into what is known as a Softphone. A Softphone allows users to place and receive calls using a PC. This article covers what a Softphone is and its issues, such as quality of service and security, which affect Softphones. The Technical Integration Center (TIC) currently does not ... |
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| Quantum Communication Systems |
15-Mar-2008 |
21 pages |
| Authors:
Ian A Walmsley; OXFORD UNIV (UNITED KINGDOM)
|
| This report results from a contract tasking University of Oxford as follows: The Grantee will investigate ....... Photonic quantum sources for scalable Linear Optics Quantum Communications (LOQC). The objective of this work package is to develop photonic sources suitable for linear optical quantum communications. This requires the efficient preparation and utilization of single- and multiple photons in pure states, with good modal quality, compatible with guided wave optics |
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| Internet Protocol (IP): The Key to Joint Communications |
19-Feb-2008 |
17 pages |
| Authors:
W W Manning; MARINE CORPS COMMAND AND STAFF COLL QUANTICO VA
|
| Internet Protocol-based systems are the answer to the continuing demands for instant communication and information sharing of today's joint warfighting challenges. The IP systems that have been implemented and are in use in Iraq and Afghanistan are performing exceptionally well. Although warfighters have previously accomplished their missions without IP technology, the implementation of IP-based systems will enhance capabilities, is cost efficient, and will enable a networked force. Robert Ackerman, SIGNAL ... |
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| Cyberspace Coercion in Phase 0/I: How to Deter Armed Conflict |
06-Nov-2007 |
25 pages |
| Authors:
Russell F Mathers; NAVAL WAR COLL NEWPORT RI JOINT MILITARY OPERATIONS DEPT
|
| Cyberspace is a war fighting domain and can be used by joint force commanders (JFC) in Phase 0 (Shape) and Phase 1 (Deter) of their operation to prevent escalation to armed conflict. This paper outlines Byman and Waxman's four coercion mechanisms of power base erosion, civil unrest, decapitation and denial and uses them and Boyd's OODA Loop as a framework to examine how a JFC can use cyberspace capabilities to ... |
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| Intelligent Advanced Communications IP Telephony Feasibility for the U.S. Navy. Volume 1 |
OCT 2007 |
456 pages |
| Authors:
Todd D. Binns; Bill Naas; L-3 COMMUNICATIONS HENSCHEL NEWBURYPORT MA
|
| The purpose of this research paper is to research technologies and solutions supporting the communications infrastructure necessary to implement an integrated VoIP (IP telephony), Video and Data infrastructure on U.S. Naval vessels. This report is based on a collection of extensive research topics: * L3 Henschel internal research * Commissioned research papers * Vendor responses to a formal questionnaire * U.S. Navy vessel specifications * Government documents focusing on network ... |
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| Energy-Efficient Querying of Wireless Sensor Networks |
SEP 2007 |
212 pages |
| Authors:
Christopher R. Mann; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT
|
| Due to the distributed nature of information collection in wireless sensor networks and the inherent limitations of the component devices, the ability to store, locate, and retrieve data and services with minimum energy expenditure is a critical network function. Additionally, effective search protocols must scale efficiently and consume a minimum of network energy and memory reserves. A novel search protocol, the Trajectory-based Selective Broadcast Query protocol, is proposed. An analytical ... |
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| A Modular Approach to Time-Based UAN Simulation Development |
SEP 2007 |
133 pages |
| Authors:
Richard Betancourt; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| The necessity to project naval combat power throughout the littorals has resulted in the explosion of growth in the development and implementation of wireless underwater networks. Contrary to the terrestrial wireless signal, which uses electromagnetic (radio) signals as a medium for the transfer of data, an underwater network utilizes acoustic signals to carry data. Additionally, unlike the terrestrial counterpart, the underwater acoustic network operates in a dynamic, ever changing environment ... |
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| RADAR Imaging Transformation for Heads Up Display Utility |
SEP 2007 |
27 pages |
| Authors:
Brian Wilson; Nikola Subotic; ALTARUM INST ANN ARBOR MI
|
| The following report discusses the display and sensor requirements for a heads up display (HUD) capable of presenting a 3-Dimensional (3-D) scene to a pilot during instrument landing that provides data indicative of barriers and obscurations in the flight path and intended landing area. The necessary equations for relating common electro-optic sensor parameters to the equivalent RADAR parameterization are provided such that a cross-sensor analysis can be performed to determine ... |
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| Effect of Reminder Telephone Calls on Mammography Compliance in High Risk Women |
01 JUN 2007 |
14 pages |
| Authors:
Carrie L. Synder; CREIGHTON UNIV OMAHA NE
|
| Even though mammography has been proven to be effective in reducing breast cancer mortality this simple screening measure is underutilized by women who are at an inordinately high risk for developing breast cancer. The effect of a reminder telephone call intervention has not been studied in this high-risk population where the need for compliance is crucial. The hypothesis for this study is that a simple reminder telephone call will significantly ... |
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| Architectures for Secure and Robust Distributed Infrastructures |
02 APR 2007 |
35 pages |
| Authors:
Sanjay Lall; Carolyn Beck; Stephen Boyd; John Doyle; Geir Dullerud; Chris Hadjicostis; Muriel Medard; Balaji Prabhakar; Rayadurgam Srikant; George Verghese; STANFORD UNIV CA DEPT OF AERONAUTICS AND ASTRONAUTICS
|
| The major barrier constraining the successful management and design of large-scale distributed infrastructures is the conspicuous lack of knowledge about their dynamical features and behaviors. Up until very recently analysis of systems such as the Internet, or the national electricity distribution system, have primarily relied on the use of non-dynamical models, which neglect their complex, and frequently subtle, inherent dynamical properties. These traditional approaches have enjoyed considerable success while systems ... |
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| Bit Error Rate Minimizing Channel Shortening Equalizers for Single Carrier Cyclic Prefixed Systems |
Apr-2007 |
5 pages |
| Authors:
Richard K Martin; Koen Vanbleu; Geert Ysebaert; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH DEPT OF ELECTRICAL AND COMPUTER ENGINEERING
|
| Single carrier cyclic prefixed (SCCP) communications are a close relative of multicarrier communications. Both types of systems are robust to multipath, provided that the channel delay spread is shorter than the guard interval between transmitted blocks. If this condition is not met, a channel shortening equalizer can be used to shorten the channel to the desired length. Previous work on channel shortening has largely been in the context of digital ... |
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| Accelerating the Kill Chain via Future Unmanned Aircraft |
Apr-2007 |
89 pages |
| Authors:
Julian C Cheater; AIR WAR COLL MAXWELL AFB AL CENTER FOR STRATEGY AND TECHNOLOGY
|
| Unmanned aircraft (UA) have evolved from simple reconnaissance assets into capable and persistent strike platforms in a short period of time. Looking ahead to the year 2025, what technologies will help the U.S. military reduce the time it takes to find, track, and neutralize a target with UA? The United States can have the greatest impact in accelerating the kill chain by investing in research that advances autonomous UA operations ... |
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| Development of a Quantum Repeater for Long-Distance Quantum Communication Using Photonic Information Storage |
14 MAR 2007 |
17 pages |
| Authors:
Mikhail Lukin; PRESIDENT AND FELLOWS OF HARVARD COLL CAMBRIDGE MA OFFICE OF SPONSORED RESEARCH
|
| In this project, we have carried out the pioneering work for long-distance quantum communication using atomic ensembles for photon-state storage and for implementation of quantum repeaters. This work was followed by many groups and is now considered as one of the most promising approaches to overcoming photon losses in long-distance quantum communication. Specific highlights include theoretical proposals for quantum repeaters based on atomic ensembles (Nature, 414, 413, 2001), atom-atom correlations ... |
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| Hybrid Steering Systems for Free-Space Quantum Communication |
MAR 2007 |
50 pages |
| Authors:
Vladimir V. Nikulin; NIKULIN (VLADIMIR V)ENDICOTT NY
|
| The proposed research will utilize a mechanical gimbal for extended range of optical connectivity, and a fast beam deflector to create a hybrid beam steering system capable of exercising a very high positioning bandwidth over a full hemisphere of steering angles. System design process will include the solution of such underlying problems as the development of the mechanical and optical subsystems, mathematical description of the hybrid device, optimal task distribution ... |
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| Analysis of United States' Broadband Policy |
MAR 2007 |
163 pages |
| Authors:
Joel S. Uzarski; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| Broadband Internet access has become an important service that affects the economic and social makeup of a country. Broadband penetration is becoming extremely important as globalization starts to interweave the economies and policies of nations around the world. With every month that passes, the United States fails to close the gap in the digital divide both inside its borders as well as among the other countries that lead the world ... |
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| Fundamentals of Combinatorial Optimization and Algorithm Design: Report for April 1 2006-March 31 2007 |
MAR 2007 |
14 pages |
| Authors:
Bruce Shepherd; Matthew Andrews; Chandra Chekuri; Gordon Wilfong; Lisa Zhang; LUCENT TECHNOLOGIES INC MURRAY HILL NJ
|
| The main research output this year included work on degree-constrained network flows which was accepted by STOC 2007. Shepherd will give a plenary talk on this topic at CANADAM. Lucent has also applied for a patent based on this work, Work was also done on protected buy-at-bulk network design problems by Antonakopoulos, Chekuri Shepherd, and Zhang resulting in a manuscript, April 2007. Work was done by Andrews and Zhang on ... |
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| Lithographically-Scribed Planar Holographic Optical CDMA Devices and Systems |
15 FEB 2007 |
58 pages |
| Authors:
Thomas Mossberg; LIGHTSMYTH TECHNOLOGIES INC EUGENE OR
|
| Recent advances in photo lithographic fabrication and planar waveguides have created a powerful opportunity. For the First time it is possible to generate arbitrary computer-designed. waveguide volume holograms and to do so robustly and at low cost. Holographic Bragg Reflectors (HBRs) comprise an exemplary lithographically scribed fully integrated holographic device useful for multiplexing of wavelength differentiated optical signals and general purpose spectral filtering. HBRs provide both a flexible spectral filtering ... |
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| Binocular Rivalry and Attention in Helmet-Mounted Display Applications |
FEB 2007 |
8 pages |
| Authors:
Marc D. Winterbottom; Robert Patterson; Byron J. Pierce; Christin Covas; Jason Rogers; LINK SIMULATION AND TRAINING MESA AZ
|
| As monocular head-mounted displays (HMDs) are introduced into existing flight simulators for training and mission rehearsal it will be important to determine whether binocular rivalry affects the visibility of HMD presented symbology or the out-the-window (OTW) flight simulator display imagery. In the present study, we examined whether rivalry suppression could be objectively measured under conditions that simulated a monocular HMD and OTW display, and whether voluntary attention and moving imagery ... |
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| The Influence of Depth of Focus on Visibility of Monocular Head-Mounted Display Symbology in Simulation and Training Applications |
FEB 2007 |
12 pages |
| Authors:
Marc D. Winterbottom; Robert Patterson; Byron J. Pierce; Christine Covas; Jennifer Winner; LINK SIMULATION AND TRAINING MESA AZ
|
| The Joint Helmet Mounted Cueing System (JHMCS) is being considered for integration into the F-15, F-16, and F-18 aircraft. If this integration occurs, similar monocular head-mounted displays (HMDs) will need to be integrated with existing out-the-window simulator systems for training purposes. One such system is the Mobile Modular Display for Advanced Research and Training (M2DART), which is constructed with flat-panel rear-projection screens around a nominal eye-point. Because the panels are ... |
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| Depth of Focus and Perceived Blurring of Simultaneously-Viewed Displays |
FEB 2007 |
12 pages |
| Authors:
Marc D. Winterbottom; Robert Patterson; Byron J. Pierce; Christine Covas; Jennifer Winner; LINK SIMULATION AND TRAINING MESA AZ
|
| Head-mounted displays (HMDs) have not previously been combined with flat-panel display systems and it was unknown whether viewing two displays at differing focal plane distances would lead to perceived blurring or visual discomfort. This is now a concern as the Joint Helmet Mounted Cueing System (JHMCS) is integrated with existing flat-panel display systems such as the Mobile Modular Display for Advanced Research and Training (M2DART). The degree of blurring that ... |
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| Chip-Scale Controlled Storage All-Optical Memory |
FEB 2007 |
28 pages |
| Authors:
Constance Chang-Hasnain; Shun Lien Chuang; CALIFORNIA UNIV BERKELEY
|
| Goal of the project was to demonstrate a semiconductor waveguide device suitable for use as an all-optical buffer with a slow down factor of 1000 at room temperature. Theoretical and experimental research was performed to show the feasibility of slow light in semiconductor quantum wells. Prototype GaAs quantum well devices were fabricated, and characterized at both cryogenic and ambient laboratory temperatures. Mechanisms such as coherent population oscillation (CPO) and electromagnetically ... |
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| Helmet Tracker Requirements and Measurement Verification |
FEB 2007 |
22 pages |
| Authors:
Gary Martinsen; Judson Shattuck; Jeffrey Craig; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH HUMAN EFFECTIVENESS DIRECTORATE
|
| A helmet tracker is a critical element in the path that delivers targeting and other sensor data to the user of a helmet-mounted display (HMD) in a military aircraft. This paper reviews helmet tracker technology with respect to use in military aviation. The human factors limitations of helmet tracker systems for delivering both targeting and flight reference information to a military pilot are also discussed. This paper also presents data ... |
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| Government Access to Phone Calling Activity and Related Records: Legal Authorities |
25 JAN 2007 |
|
| Authors:
Elizabeth B. Bazan; Gina M. Stevens; Brian T. Yeh; LIBRARY OF CONGRESS WASHINGTON DC CONGRESSIONAL RESEARCH SERVICE
|
 | Media disclosures regarding an alleged National Security Agency (NSA) program designed to collect and analyze information on telephone calling patterns within the United States have raised interest in the means by which the Government may collect such information. The factual information available in the public domain with respect to any such alleged program is limited and in some instances inconsistent, and the application, if at all, of any possibly relevant ... |
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| Future Naval Concepts -- Crew Reductions through Improved Damage Control Communications (FNC-CRIDCC), Triad Test 2 Report (18-22 Sep 2006) |
12 JAN 2007 |
70 pages |
| Authors:
Thomas T. Street; Frederick W. Williams; L. S. Cooper; III Halloway Kenneth E.; Michael Rininger; Charles Miller; Bradley Shirley; Samuel Genovese; Rendell Perry; Kenney McCombs; NAVY TECHNOLOGY CENTER FOR SAFETY AND SURVIVABILITY WASHINGTON DC
|
| The object of Triad Test 2 was to conduct and document an RF coverage survey of the installed WLAN aboard ex-USS Shadwell in a benign environment, obtain RF WLA data during fire events, and evaluate the ability of the communications equipment to continue to provide a communication capability. The fire events were used to determine the ability of the equipment to provide voice and data communications over Voice over Internet ... |
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| Wavefront Aberration Correction Using Zernike Polynomial Parameterizations of Optical Phased Arrays (PREPRINT) |
2007 |
7 pages |
| Authors:
Jeffrey A. Butterworth; Charles Hindman; Seth Lacy; AIR FORCE RESEARCH LAB KIRTLAND AFB NM SPACE VEHICLES DIRECTORATE
|
| High performance laser communication systems require adaptive optics based wavefront correction systems to correct aberrations that result from imperfections in optical hardware and atmospheric conditions. Traditionally, deformable membrane mirrors are used for wavefront correction. These mirrors are bulky and require excessive amounts of power, both of which can be detrimental to a space application. Liquid crystal based optical phased arrays (OPAs) offer an attractive alternative to these traditional devices. This ... |
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| Large Diameter, High Speed InGaAs Receivers for Free-Space Lasercom |
2007 |
13 pages |
| Authors:
H. R. Burris; M. S. Ferraro; C. I. Moore; P. G. Goetz; W. D. Waters; W. R. Clark; W. S. Rabinovich; L. M. Wasiczko; M. R. Suite; R. Mahon; NAVAL RESEARCH LAB WASHINGTON DC ADVANCED SYSTEMS TECHNOLOGY BRANCH
|
| The U. S. Naval Research Laboratory (NRL) and OptoGration, Inc. have collaborated in the development and testing of large area, high speed InGaAs avalanche photodiode (APD) receivers for use in free-space lasercom systems. A 200 micron diameter InGaAs APD receiver has been tested in a free-space lasercom testbed and has demonstrated sensitivities of -42.4 dBm at 622 Mbps and -44.8 dBm at 155 Mbps. A 100 micron diameter receiver has ... |
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| News Media Industry |
2007 |
29 pages |
| Authors:
Janet Anderson; Florentin Buhos; Ed Celentano; Yadmaa Choijamts; Iris Cooper; Ed Daniel; Nhu-Nga Do; Tara Feret-Erath; Yori R. Escalante; Paul Guinee; INDUSTRIAL COLL OF THE ARMED FORCES WASHINGTON DC
|
| The ability of US citizens to freely express their views and opinions is a gift we must never take for granted. A key means by which our government and citizens communicate is the News Media. This critical industry is now experiencing tremendous change. Technological advances have led to an explosion in communication media that now provide consumers more news options than ever before. Traditional media such as newspapers, television and ... |
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| Coordinating Initiation and Response in Computer-Mediated Communication |
DEC 2006 |
207 pages |
| Authors:
Laura A. Dabbish; CARNEGIE-MELLON UNIV PITTSBURGH PA HUMAN COMPUTER INTERACTION INST
|
| Communication interruptions make work sociable and interesting, and they support flexibility and knowledge transfer in the workplace. However, interruptions also delay task completion and degrade performance, with negative consequences for organizational effectiveness. When communication is technologically mediated, how can we maintain connectivity while reducing the potential disruption associated with informal interaction? This thesis examines factors influencing the decision to initiate and respond to communication, and the impacts of communication interactions ... |
|
| Neck Muscle Fatigue with Helmet-Mounted Systems |
SEP 2006 |
8 pages |
| Authors:
Edward S. Eveland; Joseph A. Pellettiere; HUMAN EFFECTIVENESS DIRECTORATE WRIGHT-PATTERSON AFB OH AIRCREW PROTECTION BRANCH
|
| Helmet-mounted systems (HMS) allow aircrew to perform more efficiently in poor conditions. Optics allow improved visibility, night vision, helmet-mounted displays, and targeting capability. The cost to use them in high performance aircraft is unknown. Test flights were made with pilots wearing HMS and neck muscles were evaluated. Objectives were to test the functionality of the helmet-mounted devices and to determine the impact on pilots using them during high G acceleration. ... |
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| Critical Infrastructure Protection: How to Assess and Provide Remedy to Vulnerabilities in Telecom Hotels |
SEP 2006 |
109 pages |
| Authors:
Michael A. Ordonez; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| America's open society includes a vast array of critical infrastructure and key resources that are vulnerable to terrorist attacks. While it is not possible to protect or eliminate vulnerabilities of all critical infrastructures in the United States, strategic improvements can be made to harden these assets and mitigate any damaging effects if an attack were to occur. Current network assessment methods and protective measures are inadequate. As a consequence, the ... |
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| Performance Effects of Mounting a Helmet-Mounted Display on the ANVIS Mount of the HGU-56P Helmet (Reprint) |
SEP 2006 |
11 pages |
| Authors:
Thomas H. Harding; John S. Martin; Clarence E. Rash; ARMY AEROMEDICAL RESEARCH LAB FORT RUCKER AL
|
| The U.S. Army, under the auspices of the Air Warrior Product Office, is developing a modular helmet-mounted display (HMD) for four aircraft series within its helicopter fleet. A design consideration is mounting the HMDs to the HGU-56P Aviator's Night Vision Imaging System (ANVIS) mount. This particular mount is being considered, presumably due to its inherent cost savings, as the mount is already part of the helmet. Mounting the HMD in ... |
|
| Field Tests of Acoustic Telemetry for a Portable Coastal Observatory |
Sep-2006 |
7 pages |
| Authors:
Marinna Martini; Bradford Butman; Jonathan Ware; Dan Frye; GEOLOGICAL SURVEY WOODS HOLE MA
|
| Long-term field tests of a low-cost acoustic telemetry system were carried out at two sites in Massachusetts Bay. At each site, an acoustic Doppler current profiler mounted on a bottom tripod was fitted with an acoustic modem to transmit data to a surface buoy; electronics mounted on the buoy relayed these data to shore via radio modem. The mooring at one site (24 m water depth) was custom-designed for the ... |
|
| Remote, Aerial, Trans-Layer, Linear and Non-Linear Downlink Underwater Acoustic Communication |
Sep-2006 |
8 pages |
| Authors:
Fletcher Blackmon; Lynn Antonelli; NAVAL UNDERSEA WARFARE CENTER DIV NEWPORT RI
|
| Abstract-Both the linear mechanism for optical to acoustic energy conversion are explored for opto-acoustic communication from an in-air platform to a submerged vessel such as a submarine or unmanned undersea vehicle. This downlink communication can take the form of a bell ringer function for submerged platforms or for the transmission of text and/or data. The linear conversion mechanism, also known as the linear opto-acoustic regime where laser energy is converted ... |
|
| Modeling and Interpretation of Beamforming Gain and Diversity Gain for Underwater Acoustic Communications |
Sep-2006 |
6 pages |
| Authors:
T C Yang; NAVAL RESEARCH LAB WASHINGTON DC
|
| Output signal-to-noise ratios for a multichannel decision feedback equalizer were measured from experimental BPSK data as a function of the receiver spacing, number of receivers used, and array aperture and reported in a paper in OCEANS 2005 by the author. This paper discusses the theory and reports numerical modeling results to compare with the data. |
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| Effects of Multiple Scattering on the Implementation of an Underwater Wireless Optical Communications Link |
Sep-2006 |
7 pages |
| Authors:
Alan Laux; Brandon Cochenour; Linda Mullen; Tom Curran; NAVAL AIR SYSTEMS COMMAND PATUXENT RIVER MD
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| Recent interest in ocean exploration has brought about a desire for developing wireless communication techniques in this challenging environment. Due to its high attenuation in water, a radio frequency (RF) carrier is not the optimum choice. Acoustic techniques have made tremendous progress in establishing wireless underwater links, but they are ultimately limited in bandwidth. A third option is optical radiation, which is discussed in this paper. One drawback of underwater ... |
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| Error Rate Improvement in Underwater MIMO Communications Using Sparse Partial Response Equalization |
Sep-2006 |
7 pages |
| Authors:
Vincent McDonald; Subhadeep Roy; Tolga M Duman; ARIZONA STATE UNIV TEMPE DEPT OF ELECTRICAL AND COMPUTER ENGINEERING
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| Point-to-point links using multiple transmitters and receivers or MIMO (multiple input, multiple output) configurations and associated signal processing at the receiver, can provide significant improvements in both data rate and reliability and is a promising technology for enhancing communications in the band-limited and highly-dynamic underwater acoustic (UWA) channel. Although the underwater channel impulse response extent can span tens to hundreds of symbols, it is generally sparse in nature and well ... |
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Non-radio Communications
