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1

ANIMAL COMMUNICATION.  

PubMed

Semiotics and ethology have converged in a new behavioral science, zoosemiotics. Those who are interested in the theoretical analysis of the complex problems of non-verbal behavior that arise where these two disciplines interact aim to treat comprehensively animal communication systems by the aid of representations that have proved illuminating in the study of sentences of human language. Students of zoosemiotics are concerned with codes and messages much as linguists are concerned with competence, or language, and performance, or speech. They thus face the twin tasks of constructing a model for the addresser to specify how a message is encoded and transformed into a signal carried by a variety of channels to the addressee; and of constructing a model for the addressee to specify the ways in which animals utilize their knowledge of their code to recognize the messages they receive. Finally, they assess the context of the communicative event in the hope of dissecting that which is relevant to the selection process from the rest of the background, a program for which there is as yet neither a procedural eliciting technique nor a satisfactory theoretical solution in sight. PMID:14245775

SEBEOK, T A

1965-02-26

2

Ways Animals Communicate  

ERIC Educational Resources Information Center

The authors describe a set of upper-elementary activities that focuses on how animals communicate. The activities describe procedures that students working in groups can use to investigate the topic of animal communication. An initial information sheet, resource list, and grading rubric are provided. The lesson plan was field-tested in an…

Curry, Kristen; Sumrall, William J.; Moore, Jerilou; Daniels, Anniece

2008-01-01

3

Animal Communication: What Do Animals Say?  

ERIC Educational Resources Information Center

Discusses the nature of animal communication, including possible relationships between the physical structure of vocalizations and their functions in communicating. Provides tables of mammalian and avian sounds (by species/family) used in hostile and friendly appeasing contexts. (JN)

Morton, Eugene S.

1983-01-01

4

Song type matching is an honest early threat signal in a hierarchical animal communication system  

PubMed Central

Aggressive encounters between animals often involve significant amounts of signalling before or in lieu of physical fights. When, as is often the case, these apparent threat signals are neither inherently costly nor inherently indicative of fighting ability, we should ask whether they are in fact honest signals, i.e. do they predict that escalation is imminent? While signalling theories have indicated that such ‘conventional’ threat signals can honestly predict escalation, attempts to gather supporting empirical evidence have mostly failed. For example, recent studies in songbirds of song type matching (replying to an opponent's song with the same song type he has just sung) have failed to confirm that it predicts an eventual attack by the signaller. In the present study of song sparrows (Melospiza melodia), we tested the hypothesis that song type matching is an early threat signal in a hierarchical signalling system. We used an improved model-playback design that simulated an escalating intrusion onto the subject's territory: the simulated opponent first sang in hiding from the boundary before moving to the centre of the territory, where he revealed himself and continued to sing. We found that type matching beginning in the boundary phase and continuing into the escalation phase, or beginning immediately after the escalation, reliably predicted both subsequent escalated signalling (soft songs and wing waves) and subsequent attack on the model, supporting the hypothesis that type matching is a reliable early threat signal.

Akcay, Cag?lar; Tom, Mari E.; Campbell, S. Elizabeth; Beecher, Michael D.

2013-01-01

5

The use of network analysis to study complex animal communication systems: a study on nightingale song.  

PubMed

The singing of song birds can form complex signal systems comprised of numerous subunits sung with distinct combinatorial properties that have been described as syntax-like. This complexity has inspired inquiries into similarities of bird song to human language; but the quantitative analysis and description of song sequences is a challenging task. In this study, we analysed song sequences of common nightingales (Luscinia megarhynchos) by means of a network analysis. We translated long nocturnal song sequences into networks of song types with song transitions as connectors. As network measures, we calculated shortest path length and transitivity and identified the 'small-world' character of nightingale song networks. Besides comparing network measures with conventional measures of song complexity, we also found a correlation between network measures and age of birds. Furthermore, we determined the numbers of in-coming and out-going edges of each song type, characterizing transition patterns. These transition patterns were shared across males for certain song types. Playbacks with different transition patterns provided first evidence that these patterns are responded to differently and thus play a role in singing interactions. We discuss potential functions of the network properties of song sequences in the framework of vocal leadership. Network approaches provide biologically meaningful parameters to describe the song structure of species with extremely large repertoires and complex rules of song retrieval. PMID:24807258

Weiss, Michael; Hultsch, Henrike; Adam, Iris; Scharff, Constance; Kipper, Silke

2014-01-01

6

Information theory, animal communication, and the search for extraterrestrial intelligence  

Microsoft Academic Search

We present ongoing research in the application of information theory to animal communication systems with the goal of developing additional detectors and estimators for possible extraterrestrial intelligent signals. Regardless of the species, for intelligence (i.e., complex knowledge) to be transmitted certain rules of information theory must still be obeyed. We demonstrate some preliminary results of applying information theory to socially

Laurance R. Doyle; Brenda McCowan; Simon Johnston; Sean F. Hanser

2011-01-01

7

Communication across the curriculum in animal science.  

PubMed

The growing movement toward the integration of communications in science-based courses has been taken to the heart of the curriculum at Berea College. New college-wide general education requirements initiated a review of student abilities, departmental expectations, and the use of writing and speaking skills in all courses. Agriculture graduates require highly developed reading and speaking skills as well as fundamental control of language to succeed in industry today. Depending only on the English department to teach students writing and speaking skills can lead to graduates ill-prepared for communication in their chosen profession. The inclusion of communication skills in an animal science course not only improves such skills, but it also increases the ability of students to apply and use animal science concepts. The benefits of broadening the teaching curriculum to include reading, writing, speaking, and listening skills can provide improved academic achievement, attitude, confidence levels, and self-images. Students can become active participants rather than note-takers. Curriculum changes of such magnitude require faculty development opportunities and administrative support. PMID:8923197

Orr, C L

1996-11-01

8

Digital Communication System.  

National Technical Information Service (NTIS)

A closed-loop, digital data communication system utilizing an optimum number of interconnecting wires is described. The system has particular application in a space vehicle where it may be desired to communicate voice or other transducer-derived informati...

L. G. Monford

1972-01-01

9

Personal communication systems (PCS)  

Microsoft Academic Search

Personal communication systems (PCS) represent a rapidly growing and increasingly important segment of the telecommunication industry. The goal of PCS is to provide truly personal, cost-efficient communication services to users through portable handsets. In this paper, we present a survey on the research and development in PCS, emphasizing several important aspects such as the PCS concept, service requirements, system architecture,

V. O. K. Li; Xiaoxin Qiu

1995-01-01

10

Animal Communication and Its Cognitive Indications.  

ERIC Educational Resources Information Center

Various examples of communication in species ranging from bumble bees to dolphins are examined in this paper. Focus is directed to indications of the cognitive ability of each species. The signals of cognition include evidence of: adaptability to a new situation; long term memory; and the property of displacement. Most of the sources reviewed…

McLean, Laura L.

11

Military Satellite Communications Systems.  

National Technical Information Service (NTIS)

MILSATCOM systems consist of three primary segments: earth terminal (airborne, ground, sea) segment, sp segment, and control segment. MILSATCOM systems are vital to Department of Defense as they satisfy certain essential communications connectivity needs ...

1992-01-01

12

Digital communication systems  

NASA Astrophysics Data System (ADS)

The fundamental principles of digital communication and the design of practical digital communication systems are explored in an introductory textbook for senior and graduate students of electrical engineering. Chapters are devoted to sampling principles, baseband digital waveforms, baseband digital systems, bandpass binary digital systems, and M-ary digital systems. Deterministic signals, networks, and random-signal theory are reviewed in extensive appendices, and graphs, flow charts, diagrams, and problems are provided.

Peebles, Peyton Z., Jr.

13

Secure Sonar Communication System.  

National Technical Information Service (NTIS)

A secure sonar communication system for transmitting and receiving intelligence signals within an aqueous medium comprising in combination means for generating an electrical pseudo random noise signal within a predetermined bandwidth, means connected to s...

R. D. Isaak W. E. Klund W. H. Littrell R. G. Stephenson

1980-01-01

14

AMPA experimental communications systems  

NASA Technical Reports Server (NTRS)

The program was conducted to demonstrate the satellite communication advantages of Adaptive Phased Array Technology. A laboratory based experiment was designed and implemented to demonstrate a low earth orbit satellite communications system. Using a 32 element, L-band phased array augmented with 4 sets of weights (2 for reception and 2 for transmission) a high speed digital processing system and operating against multiple user terminals and interferers, the AMPA system demonstrated: communications with austere user terminals, frequency reuse, communications in the face of interference, and geolocation. The program and experiment objectives are described, the system hardware and software/firmware are defined, and the test performed and the resultant test data are presented.

Beckerman, D.; Fass, S.; Keon, T.; Sielman, P.

1982-01-01

15

Communicating Networked Control Systems.  

National Technical Information Service (NTIS)

This report describes research conducted over a twelve month period under support from a multi-university research grant whose focus is the technological foundations of Communicating Networked Control Systems. Coordinated efforts at four participating ins...

J. Baillieul P. R. Kumar P. S. Krishnaprasad R. W. Brockett

2007-01-01

16

Airborne wireless communication systems, airborne communication methods, and communication methods  

DOEpatents

An airborne wireless communication system includes circuitry configured to access information describing a configuration of a terrestrial wireless communication base station that has become disabled. The terrestrial base station is configured to implement wireless communication between wireless devices located within a geographical area and a network when the terrestrial base station is not disabled. The circuitry is further configured, based on the information, to configure the airborne station to have the configuration of the terrestrial base station. An airborne communication method includes answering a 911 call from a terrestrial cellular wireless phone using an airborne wireless communication system.

Deaton, Juan D. (Menan, ID); Schmitt, Michael J. (Idaho Falls, ID); Jones, Warren F. (Idaho Falls, ID)

2011-12-13

17

Refining Interfaces of Communicating Systems.  

National Technical Information Service (NTIS)

There are now several theories for describing and reasoning about the behavior of communicating systems, where the behavior of a communicating system is described in terms of its capabilities to perform communication actions in cooperation with its enviro...

E. Brinksma B. Jonsson F. Orava

1991-01-01

18

Digital communication system  

NASA Technical Reports Server (NTRS)

A digital communication system is reported for parallel operation of 16 or more transceiver units with the use of only four interconnecting wires. A remote synchronization circuit produces unit address control words sequentially in data frames of 16 words. Means are provided in each transceiver unit to decode calling signals and to transmit calling and data signals. The transceivers communicate with each other over one data line. The synchronization unit communicates the address control information to the transceiver units over an address line and further provides the timing information over a clock line. A reference voltage level or ground line completes the interconnecting four wire hookup.

Monford, L. G., Jr. (inventor)

1974-01-01

19

Serial interprocessor communications system  

SciTech Connect

A serial communications system based on the EIA RS232-C standard with modem control lines has been developed. The DLV11-E interface is used for this purpose. All handshaking is done with the modem control lines. This allows totally independent full duplex communication. The message format consists of eight bit data with odd parity and a sixteen bit checksum on the whole message. All communications are fully interrupt driven. A program was written to load a program into a remote LSI-11 using the serial line without bootstrap ROM.

Labiak, W.; Siemens, P.; Bailey, C.

1980-04-03

20

The risk communication challenges of mass animal destruction.  

PubMed

Mass animal destruction strategies present a major risk communication challenge. While mass culling, stamping out, and depopulation may be scientifically and economically justified during emergency response to exotic disease incursions and eradication programmes, their use may be limited in the future due to public concerns over animal welfare, environmental contamination and unintended social consequences. To address this dilemma, official veterinary services must move from unidirectional communications strategies to active engagement of all potentially affected stakeholders. Case studies of recent disease outbreaks demonstrate the critical role that communications play in influencing public reaction to disease management strategies. An evaluation of these case studies provides support for the implementation of risk communication best practices: incorporating risk communications into the policy-development process, conducting pre-event planning, fostering partnerships with the public, collaborating with credible sources, meeting the needs of the media, listening to and addressing public concerns, communicating with compassion and empathy, demonstrating honesty and openness, acknowledging uncertainty and providing messages that give people meaningful things to do. Implementing the risk communication best practices requires veterinary services to move from a more technocratic approach to a participatory model where the potentially affected public play an active role in risk assessment and policy making. PMID:20411519

Hueston, William D

2007-01-01

21

DYMAC communications system  

SciTech Connect

The DYMAC Communications System is part of a nuclear safeguards system called DYMAC - short for DYnamic Materials ACcountability - that gathers accountability information at the Los Alamos Scientific Laboratory (LASL) Plutonium Processing Facility. The communications system handles transmissions between data-entry terminals and nondestructive assay (NDA) instruments located in the facility, and a computer located in an adjacent building. System design emphasizes reliability rather than high speed to ensure the integrity of data transmissions. This manual is directed toward the person responsible for maintaining the DYMAC Communication System. It describes the components that make up the communications network, explains how they operate, and gives detailed information about all of the connections. Many of the system components are commercially available; some have been modified at LASL for DYMAC purposes; others were designed and fabricated at LASL. This manual provides circuit diagrams for all of the LASL modifications and LASL-fabricated equipment. In addition, it provides a series of procedures for tracing cables, reconfiguring various parts of the system, testing data transmissions, and troubleshooting malfunctions.

Lindsey, K.A.

1980-01-01

22

INCO shuttle communication system  

NASA Technical Reports Server (NTRS)

In a previous work we have defined a general architectural model for autonomous systems, which can be mapped easily to describe the functions of any automated system (SDAG-86-01). In this note, we use the model to describe the Shuttle communication system. First we briefly review the architecture, then we present the environment of our application, and finally we detail the specific function for each functional block of the architecture for that environment.

Dikshit, Piyush; Guimaraes, Katia; Ramamurthy, Maya; Agrawala, Ashok K.; Larsen, Ronald L.

1989-01-01

23

Communication Systems. Laboratory Activities.  

ERIC Educational Resources Information Center

This communication systems guide provides teachers with learning activities for secondary students. Introductory materials include an instructional planning outline and worksheet, an outline of essential elements, a list of objectives, a course description, and a content outline. The guide contains 32 modules on the following topics: story…

Sutherland, Barbara, Ed.

24

Wireless Headset Communication System  

NASA Technical Reports Server (NTRS)

System combines features of pagers, walkie-talkies, and cordless telephones. Wireless headset communication system uses digital modulation on spread spectrum to avoid interference among units. Consists of base station, 4 radio/antenna modules, and as many as 16 remote units with headsets. Base station serves as network controller, audio-mixing network, and interface to such outside services as computers, telephone networks, and other base stations. Developed for use at Kennedy Space Center, system also useful in industrial maintenance, emergency operations, construction, and airport operations. Also, digital capabilities exploited; by adding bar-code readers for use in taking inventories.

Lau, Wilfred K.; Swanson, Richard; Christensen, Kurt K.

1995-01-01

25

Space Launch System Animation  

NASA Video Gallery

NASA is ready to move forward with the development of the Space Launch System -- an advanced heavy-lift launch vehicle that will provide an entirely new national capability for human exploration be...

26

Emergency Medical Services Communications Systems.  

National Technical Information Service (NTIS)

A booklet on emergency medical services (EMS) communications systems is presented as an aid for communities interested in developing a communications network to serve their emergency medical care needs. The material is intended for use by persons with som...

1972-01-01

27

A system for algorithm animation  

Microsoft Academic Search

A software environment is described which provides facilities at a variety of levels for “animating” algorithms: exposing properties of programs by displaying multiple dynamic views of the program and associated data structures. The system is operational on a network of graphics-based, personal workstations and has been used successfully in several applications for teaching and research in computer science and mathematics.

Marc H. Brown; Robert Seclgewick

1984-01-01

28

Intersputnik communications systems  

NASA Astrophysics Data System (ADS)

The legal and technical bases for "Intersputnik" were developed within the framework of cooperation among the socialist countries in the sphere of conquering and using outer space for peaceful purposes in the "Intercosmos" program. Its activities are based on respect of sovereignty, noninterference in internal affairs, mutual assistance, and mutual benefit. "Intercosmos" is an open intergovernmental organization in which any state may become a member that recognizes its aims and principles of activity, and undertakes the obligations which ensue from the agreement. Its ruling body is the Council, composed of one individual per number nation. The executive and administrative body is the Directorate. The "Intersputnik" system of communications consists of a space complex and Earth stations. Under lease agreements, Soviet artificial Earth satellites of the "Statsionar" type are used. They are located on a geocentric, circular orbit at points 14 degrees west longitude (Atlantic region) and 53 degrees east longitude (Indian region). The orbit lies in the plane of the equator at an altitude of about 36,000 km from the Earth's surface.

Romantsov, V.

1982-03-01

29

Adaptive Digital Communication System.  

National Technical Information Service (NTIS)

Variable rate, bidirectional digital communication is provided by an apparatus composed of a variable rate Manchester encoder/decoder coupled to a modulator which produces signals appropriate for transmission, and to a demodulator which extracts informati...

R. L. Gowan H. A. Quesnell

1980-01-01

30

Quantum Communications Systems.  

National Technical Information Service (NTIS)

This project supported research activities for making quantum- enhanced communications and metrology practical. The strategy was to develop robust photonic quantum states and sensors serving as an archetype for loss- tolerant information acquisition beyon...

I. A. Walmsley

2012-01-01

31

A New Underwater Communication System.  

National Technical Information Service (NTIS)

A functional prototype of a new sonar modem is undergoing preliminary testing. The leading edge technologies being used to implement the system allow programmable modifications of the system to suit a range of data communication needs. The studies reporte...

N. Doelling

1980-01-01

32

Voice communication research evaluation system  

NASA Astrophysics Data System (ADS)

Aircraft voice communications may be degraded by a variety of sources such as electrical and/or acoustical noise, radio interference, jamming and various other forms of distraction. The Voice Communication Research and Evaluation System, located in the Biodynamics and Bioengineering Division of the Aerospace Medical Research Laboratory, has been developed for the comprehensive analysis and enhancement of operational voice communication. The basic system is comprised of a multi-station voice communication network consisting of the USAF standard aircraft intercommunication system, a standard A-19 diluter-demand oxygen regulation system and an on line computer data collection and data analysis system that displays results in real time. The system is housed in a large reverberation chamber containing a programmable sound source capable of reproducing the spectrum and level of any AF operational noise environment. Standardized voice communication effectiveness test materials are used to assess the performance of any aspect of the total voice communication link, however, emphasis is usually placed upon the performance of the aircrew members. This paper will descibe the salient features of this unique system and provide examples of its application to voice communication problems.

McKinley, R. L.

1980-05-01

33

Communication, Work Systems and HRD  

ERIC Educational Resources Information Center

Purpose: The purpose of this article is to show the foundational place that communication theory and its practice occupies in functioning work systems. Design/methodology/approach: This paper defines the word communication in terms of the creation and interpretation of displays, describes what it means to have a theoretical foundation for a…

Pace, R. Wayne

2013-01-01

34

Natural communication with information systems  

Microsoft Academic Search

Pervasive networking and sophisticated computing open opportunities for collaborative information processing independent of time and space. In this instance the information system becomes an enhancer of human intellect, as well as a mediator for communication among participants. The human user favors the sensory dimensions of sight, sound, and touch as primary channels of communication. Machines that can accommodate these modes

IVAN MARSIC; ATTILA MEDL; JAMES FLANAGAN

2000-01-01

35

Remote Adaptive Communication System.  

National Technical Information Service (NTIS)

This paper presents a new approach to the development of communication tools for handicapped people. The aim is to provide with a set of capabilities which allows them to interact with their environment. The new methodology that we are presenting is inspi...

F. Fernandez L. Roa

2001-01-01

36

Animation-Based Interactive Storytelling System  

Microsoft Academic Search

This paper introduces an animation story generation system called WordsAnime using the animation database provided by animation\\u000a Consumer Generated Media. A user generates a story by repeating the steps of inputting scenarios and viewing animations. The\\u000a system presents manual, semiautomatic, and fully automatic modes of creating scenarios using a common knowledge base that\\u000a links different scenarios with each other.

Kaoru Sumi

2008-01-01

37

Patient Communication: A Multidisciplinary Approach Using Animated Cartoons  

ERIC Educational Resources Information Center

Communication is a major problem in the management of patients. Miscommunication occurs frequently in populations with low reading skills, illiteracy does not completely account for the observed low rates of recall of communicated information. Transmission of the message also plays an important role. Successful strategies to improve communication

Leiner, Marie; Handal, Gilbert; Williams, Darryl

2004-01-01

38

An impulse radio communications system  

NASA Astrophysics Data System (ADS)

Pulson Communications has built a prototype impulse radio. The transmitter has an average power of 450 microwatts as measured out of the antenna. This prototype, transmitting high quality audio, was tested to ranges in excess of 7 kilometers. The potential range of this type of system at this power level may exceed 20 kilometers. The prototype had a center frequency of 675 MHz and an approximately equal bandwidth. We used a small wideband omni-directional antenna. While Pulson's laboratory hardware has been optimized for short range, there is no theoretical reason it could not be used for longer range communications, e.g., satellite-to-ground communications or interplanetary probes.

Withington, Paul, II; Fullerton, Larry W.

1993-01-01

39

Meteor burst communication system  

NASA Astrophysics Data System (ADS)

A meteor burst communication network is disclosed that consists of a plurality of meteor burst communication stations that relay radio messages off of meteor burst trails from one station to another. Each station includes an antenna operably coupled to a receiver and transmitter, a display, a message input device, a computer operably connected to the aforementioned equipment, and a clock that provides a time base to the computer. The computer provides instructions to the transmitter and outputs to a display. The program determines if a message has been received by the receiver. If a message has been received, it is stored in the computer memory. The computer then instructs the transmitter to transmit a probing message for a predetermined period of time. If a response to the probing message has been detected by the receiver, the computer directs the transmitter to cease transmitting the probing message, transmit the message, and purge the message from memory after an acknowledgement message is received that the message was received. In cases where the probing message has been transmitted for a period in excess of the predetermined period, the computer directs the transmitter to cease transmitting and purge the message from memory. Messages may also be input into the station through the message input device.

Bickel, John E.

1992-06-01

40

Three Corner Sat Communications System  

NASA Technical Reports Server (NTRS)

Three Corner Satellite is a constellation of three nanosatellites designed and built by students. New Mexico State University has taken on the design of the communications system for this constellation. The system includes the forward link, return link, and the crosslink. Due to size, mass, power, and financial constraints, we must design a small, light, power efficient, and inexpensive communications system. This thesis presents the design of a radio system to accomplish the data transmission requirements in light of the system constraints. In addition to the hardware design, the operational commands needed by the satellite's on-board computer to control and communicate with the communications hardware will be presented. In order for the hardware to communicate with the ground stations, we will examine the link budgets derived from the radiated power of the transmitters, link distance, data modulation, and data rate for each link. The antenna design for the constellation is analyzed using software and testing the physical antennas on a model satellite. After the analysis and testing, a combination of different systems will meet and exceed the requirements and constraints of the Three Corner Satellite constellation.

Anderson, Bobby; Horan, Stephen

2000-01-01

41

Advanced satellite communication system  

NASA Technical Reports Server (NTRS)

The objective of this research program was to develop an innovative advanced satellite receiver/demodulator utilizing surface acoustic wave (SAW) chirp transform processor and coherent BPSK demodulation. The algorithm of this SAW chirp Fourier transformer is of the Convolve - Multiply - Convolve (CMC) type, utilizing off-the-shelf reflective array compressor (RAC) chirp filters. This satellite receiver, if fully developed, was intended to be used as an on-board multichannel communications repeater. The Advanced Communications Receiver consists of four units: (1) CMC processor, (2) single sideband modulator, (3) demodulator, and (4) chirp waveform generator and individual channel processors. The input signal is composed of multiple user transmission frequencies operating independently from remotely located ground terminals. This signal is Fourier transformed by the CMC Processor into a unique time slot for each user frequency. The CMC processor is driven by a waveform generator through a single sideband (SSB) modulator. The output of the coherent demodulator is composed of positive and negative pulses, which are the envelopes of the chirp transform processor output. These pulses correspond to the data symbols. Following the demodulator, a logic circuit reconstructs the pulses into data, which are subsequently differentially decoded to form the transmitted data. The coherent demodulation and detection of BPSK signals derived from a CMC chirp transform processor were experimentally demonstrated and bit error rate (BER) testing was performed. To assess the feasibility of such advanced receiver, the results were compared with the theoretical analysis and plotted for an average BER as a function of signal-to-noise ratio. Another goal of this SBIR program was the development of a commercial product. The commercial product developed was an arbitrary waveform generator. The successful sales have begun with the delivery of the first arbitrary waveform generator.

Staples, Edward J.; Lie, Sen

1992-01-01

42

The evolving defense communications system  

NASA Astrophysics Data System (ADS)

Command, control, and communications (C3) systems 'help lift the fog of war that adds uncertainty to any military operation.' They multiply the effectiveness of weapon systems and are critical components of our nation's warfighting capability. One of these critical systems is the Defense Communications System (DCS) which evolved over the past 30 years. Several factors drove this evolution, including constrained budgets, the need to improve the effectiveness and efficiency of the service provided, compatibility and interoperability, and technological advances. Based on lessons learned from Desert Shield/Desert Storm and the changing environment, force structure, and strategy, it is time to advance the DCS to its next stage. The future DCS must be flexible enough to adapt to any situation anywhere in the world. Mobile, modular building block packages of communications equipment must be available to provide effective communications capability to deployed units immediately upon arrival. Total integration and interoperability among military, commercial, and other government agencies' communication systems is a must if survivable, robust connectivity is going to be available when needed. Integration planning must begin now.

Testa, Ann M.; Jones, Walter I.

1992-05-01

43

A new underwater communication system  

Microsoft Academic Search

A functional prototype of a sonar modem was tested. The leading edge technologies were used to implement the system to allow programmable modifications of the system to suit a range of data communication needs. Questions concerning user needs and applications were addressed. Bibtex entry for this abstract Preferred format for this abstract (see Preferences) Find Similar Abstracts: Use: Authors Title

N. Doelling

1980-01-01

44

Progressive Communication Satellite Systems Design  

Microsoft Academic Search

This paper describes the progressive design, on a phased basis, of a typical communication satellite system capable of meeting a variety of military and civilian applications, The system philosophy stresses reliability and flexibility of operation, with provision for both point-to-point and area coverage, to serve both fixed and mobile ground terminals, and to operate in either a military or nonmilitary

J. E. Bartow; D. L. Jacoby; G. N. Krassner

1960-01-01

45

Video database system for studying animal behavior  

NASA Astrophysics Data System (ADS)

Classification of farm animal behaviors are based upon oral or written descriptions of the activity that an animal is engaged in. The quantification of animal behavior for research requires that an individual recognize and code the behavior of the animal under study. The classification of these behaviors can be subjective and may differ among observers. Illustrated guides to animal behavior do not convey the motion associated with most behaviors. Video based guides offer a subjective method of quantifying behaviors with real time demonstrations of the components that make up a behavior. In this paper, we propose an animal behavior video database system which can automatically extract animal motion information from the input animal activity video clip by a multi-object tracking and reasoning system. The extracted information is then analyzed and described using a set of standard animal behavior terms we are developing. The behavior description is used to automatically annotate the given video clip, and serves as the content-based index. The user of the system is able to use a keywork description of the behavior to retrieve the corresponding video object. The intended applications of the system are animal and veterinary science education, and animal behavior research. The prototype system is built for swine and will be extended to other farm animal species.

Jiang, Haitao; Dailey, Jeffery W.

1996-11-01

46

Secure communications system  

NASA Technical Reports Server (NTRS)

System employs electronically randomized variant of quadraphase modulation and demodulation between two synchronized transceivers. System uses off-the-shelf components. It may be used with digital data, command signals, delta-modulated voice signals, digital television signals, or other data converted to digital form.

Doland, G. D.

1977-01-01

47

The ORBCOMM data communications system  

NASA Technical Reports Server (NTRS)

The ORBCOMM system is designed to provide low-cost, two-way data communications for mobile and remote users. The communications system is ideally configured for low data rate applications where communicating devices are geographically dispersed and two-way communications through terrestrial means is cumbersome and not cost effective. The remote terminals use VHF frequencies which allow for the use of very small, low-cost terminals. ORBCOMM has entered into joint development agreements with several large manufacturers of both consumer and industrial electronics to design and build the remote terminals. Based on prototype work, the estimated retail cost of these units will range from $50 to $400 depending on the complexity of the design. Starting in the fall of 1993, ORBCOMM will begin service with a demonstration network consisting of two operating satellites. By the end of 1994, a full operating network of 26 satellites, four Gateway Earth Stations, and a Network Control Center will be in place. The full constellation will provide full coverage of the entire world with greater than 94 percent communications availability for the continental U.S. This paper describes the ORBCOMM system, the technology used in its implementation, and its applications.

Schoen, David C.; Locke, Paul A.

1993-01-01

48

Communication Concepts for Mobile Agent Systems  

Microsoft Academic Search

Driven by the question how to identify potential communication partners and the need for well-suited communication schemes in agent-based systems, we discuss two communication concepts: sessions and global event management.

Joachim Baumann; Fritz Hohl; Nikolaos Radouniklis; Kurt Rothermel; Markus Straßer

1997-01-01

49

Considerations for Lunar Colony Communications Systems.  

National Technical Information Service (NTIS)

This paper addresses system aspects of communications for a lunar colony. Human factors are particularly noted. The practical aspects of communications infrastructure are emphasized rather than specific technologies. Communications needs for mission suppo...

R. P. Dowling

1992-01-01

50

Animal communication: reading lizards' body language in context.  

PubMed

A recent study has shown that Jacky lizards adjust their movement-based visual signaling in response to the varying environmental conditions; the results indicate that this species has highly sophisticated communication and sensory processing strategies. PMID:17878050

Zanker, Johannes M

2007-09-18

51

Time reversal communication system  

DOEpatents

A system of transmitting a signal through a channel medium comprises digitizing the signal, time-reversing the digitized signal, and transmitting the signal through the channel medium. The channel medium may be air, earth, water, tissue, metal, and/or non-metal.

Candy, James V. (Danville, CA); Meyer, Alan W. (Danville, CA)

2008-12-02

52

Communication synthesis for distributed embedded systems  

Microsoft Academic Search

Abstract: Communication synthesis is an essential step in hardware-software co-synthesis: many embedded systems use custom communication topologies and the communication links are often a significant part of the system cost. This paper describes new techniques for the analysis and synthesis of the communication requirements of embedded systems during co-synthesis. Our analysis algorithm derives delay bounds on communication in the system

Ti-Yen Yen; Wayne Wolf

1995-01-01

53

Analyzer communications with control systems  

SciTech Connect

Analyzer systems can be interfaced directly to the high-speed data bus of a digital distributed control system as a means of improving reliability and cost-effectiveness. Composition information from multiple chromatographs and other continuous analyzers can be collected and relayed over a single high-speed link directly to the data bus of the control system. This system provides the advantages of a high-speed digital link to a host computer and the reliability of direct communications with the control system. Two process applications are discussed which demonstrate the effectiveness of direct process analyzer interface to a communications network, particularly when analyzers are used for closed-loop control. Cost can be reduced, while loop security is considerably increased.

Earle, W.; Hall, G.F.; Williams, R.A.; Villalobos, R.

1986-12-01

54

A Digital Loop Communication System  

Microsoft Academic Search

In this concise paper, we describe the concept of a local loop communication system with distributed control. Digital signals offered by the subscribers are parceled and transmitted in blocks to their destination using address-coding. Access of the terminals to the loop is gained by switching a delay network (shift register, containing the message block to be transmitted) into the loop

E. Hafner; Z. Nenadal; M. Tschanz

1974-01-01

55

Digital Chaotic Synchronized Communication System  

Microsoft Academic Search

The experimental study of a secure chaotic synchronized communication system is presented. The synchronization between two digital chaotic oscillators, serving as a transmitter-receiver scheme, is studied. The oscillators exhibit rich chaotic be- havior and are unidirectionally coupled, forming a master-slave topology. Both the input information signal and the trans- mitted chaotic signal are digital ones.

S. G. Stavrinides; A. N. Anagnostopoulos; A. N. Miliou; A. Valaristos; L. Magafas; K. Kosmatopoulos; S. Papaioannou

2009-01-01

56

The HTV Proximity Communication System  

NASA Astrophysics Data System (ADS)

National Space Development Agency of Japan (NASDA) is developing the H-II Transfer Vehicle (HTV) as an unmanned logistic support vehicle for the International Space Station (ISS). The HTV, which is launched by the H-IIA rocket, transports both pressurized and un-pressurized cargoes to the ISS, reloads disposal items from the ISS and performs destructive reentry over ocean area. NASDA plans the first flight of HTV in 2005 for demonstration. The HTV will contribute the ISS assembly and logistic re-supply operations with international commonality. For unmanned vehicle operation, communication link is critical with commanding and control, especially in proximity region to the ISS. As for the HTV operation, NASDA is developing dedicated communication system installed on the Japanese Experiment Module (JEM) of the ISS, which is called the Proximity Communication System (PROX). The HTV receives commands and transmits telemetry data through the PROX in its proximity operation to the ISS. To achieve this, the PROX can communicate with the HTV on its nominal trajectory within 23km of the ISS. Especially within 3km of the ISS, the PROX has capability to perform omni-directional communication to the HTV. The PROX also has GPS receiver and send GPS data to the HTV to support the HTV navigation for relative GPS navigation used in "far" range (500m away from the ISS). In addition to the above fundamental functions, the PROX has a capability of range and range-rate measurement between the ISS and the HTV by the pseudo noise (PN) code epoch and the Doppler shift frequency. This provides a reference data independent of "main" navigation methods (rendezvous sensor navigation or GPS navigation) of the HTV. The PROX also assists the ISS crew with its commanding device, called the Hardware Command Panel (HCP), to issue time-dependent safety-related critical commands for HTV berthing/un-berthing operation. When a failure occurs somewhere on "communication path" from the PROX Base Band Processor (BBP) to the HTV Guidance and Control Computer (GCC) including data handling and communication equipments, the PROX detects it by monitoring interruption of the "heartbeat" signal and conducts automatic redundancy switching of all the equipments on that "communication path" including those of the HTV. This paper describes the PROX functions such as communication, data handling and GPS navigation and some unique functions for the HTV proximity operation to the ISS.

Harada, Motoyuki; Takahashi, Tetsuo; Tanaka, Tetsuo

2002-01-01

57

wildCENSE: GPS based animal tracking system  

Microsoft Academic Search

wildCENSE is a Wireless Sensor Network (WSN) system which attempts to monitor the behaviour and migration patterns of Barasingha (Swamp Deer). The system would collect the micro-climatic as well as positional information of the animal and communicate it to a base station through flooding of data using peer-to-peer network. The base station, using a gateway, will upload all the collected

V. R. Jain; R. Bagree; A. Kumar; P. Ranjan

2008-01-01

58

A multilevel soliton communication system  

Microsoft Academic Search

A multilevel soliton communication system is proposed and assessed. In this system, at the transmitter end each channel transmits its data via fundamental solitons with a pre-specified amplitude (i.e., soliton width). At the receiver end we take advantage of the sensitive relationship between the amount or fundamental soliton self-wavelength shift and the width of the soliton in the subpicosecond region.

Hamid Hatami-Hanza; Amir Mostofi; Pak L. Chu

1997-01-01

59

NASA advanced communications systems analysis  

NASA Technical Reports Server (NTRS)

The purpose of the paper is to investigate and study in-depth market and system analysis for improving satellite communications. The analyses fall into two categories: the broad, scoping efforts intended to screen potential candidates and studies to develop viable operational system configurations and identify critical technology elements. To illustrate the approach, the results of 30/20 GHz study efforts which have been under way in the past few years are reviewed in detail.

Ward, J. J.

1979-01-01

60

Information Communication System at Tsukuba EXPO'85  

NASA Astrophysics Data System (ADS)

At Tsukuba EXPO'85 information communication system which employs the most advanced technology such as optical technology, is operated to conduct EXPO information guide, environmental and security control at the site, and office management, which is effective for smooth management of Exposition and appropriate service to visitors. The author outlines the characteristics of the whole communication system, and also describes how communication system using optical technology is located in the whole communication system, and the system outline.

Sakagami, Yasuhiko

61

Animal and\\/as Medium: Symbolic Work in Communicative Regimes  

Microsoft Academic Search

This paper addresses the widespread imagery of animals in contemporary media culture. Focusing on advertising for cell phones, it suggests that dogs and monkeys mediating between phones and users carry pedagogical messages that work across and underneath the surfaces of corporate advertising. Images from this well orchestrated campaign reveal a shift in how technologies are marketed to youths. Analyzing first

Jody Berland

2009-01-01

62

How plant–animal interactions signal new insights in communication  

Microsoft Academic Search

Fundamental concepts about the diversity and evolution of signals have been developed mainly in the context of sexual selection. Here, we review the functional ecology of signals in a different context, that of plant-animal interactions. The visual signals of fruits and flowers are relatively constant and clear in the message that they convey. Thus, plant signals present a particularly suitable,

H. Martin Schaefer; Veronika Schaefer; Douglas J. Levey

2004-01-01

63

Short-range communication system  

NASA Technical Reports Server (NTRS)

A short-range communication system includes an antenna, a transmitter, and a receiver. The antenna is an electrical conductor formed as a planar coil with rings thereof being uniformly spaced. The transmitter is spaced apart from the plane of the coil by a gap. An amplitude-modulated and asynchronous signal indicative of a data stream of known peak amplitude is transmitted into the gap. The receiver detects the coil's resonance and decodes same to recover the data stream.

Alhorn, Dean C. (Inventor); Howard, David E. (Inventor); Smith, Dennis A. (Inventor)

2012-01-01

64

System Study of Coal Mine Communications.  

National Technical Information Service (NTIS)

The research involved a three-phase program to establish a data base, perform communication system analysis and optimization, and prepare equipment specifications to be included in this final report. Communication system requirements and constraints were ...

1974-01-01

65

Complexity in Animal Communication: Estimating the Size of N-Gram Structures  

NASA Astrophysics Data System (ADS)

In this paper, new techniques that allow conditional entropy to estimate the combinatorics of symbols are applied to animal communication studies to estimate the communication's repertoire size. By using the conditional entropy estimates at multiple orders, the paper estimates the total repertoire sizes for animal communication across bottlenose dolphins, humpback whales, and several species of birds for N-grams length one to three. In addition to discussing the impact of this method on studies of animal communication complexity, the reliability of these estimates is compared to other methods through simulation. While entropy does undercount the total repertoire size due to rare N-grams, it gives a more accurate picture of the most frequently used repertoire than just repertoire size alone.

Smith, Reginald

2014-01-01

66

Animal Welfare in organic framing systems  

Microsoft Academic Search

The concept of farm animal welfare can, for practical purposes, be translated into the so-called Five Freedoms.[1] Organic farming aims to meet animal welfare needs and should therefore comply with these Freedoms. The first Freedom, from hunger and thirst, is met in any system properly managed to organic standards. The Freedom from thermal and physical discomfort is challenged as organic

Hans AM Spoolder

2007-01-01

67

Communications Systems for Mobile Robotics  

SciTech Connect

Performance Confirmation is the activity by which the Yucca Mountain Project confirms that the engineered and natural containment barriers of this national nuclear waste repository are performing as predicted, so that an eventual decision to close the repository can be made. This activity involves systems that must be inspected and, in some cases, serviced by mobile robots. This paper discusses systems for underground mobile robot communications, including requirements, environments, options, issues, and down-select criteria. We reviewed a variety of systems, including Slotted Waveguide, Powerline Carrier, Leaky Feeder, Photonic Bandgap Fiber, Free-Space Optics, Millimeter Waves, Terahertz Systems, and RF Systems (including IEEE 802.11 a,b, and g, and Ultra-Wideband radio).

Futterman, J A; Pao, H

2003-12-08

68

Core systems of geometry in animal minds  

PubMed Central

Research on humans from birth to maturity converges with research on diverse animals to reveal foundational cognitive systems in human and animal minds. The present article focuses on two such systems of geometry. One system represents places in the navigable environment by recording the distance and direction of the navigator from surrounding, extended surfaces. The other system represents objects by detecting the shapes of small-scale forms. These two systems show common signatures across animals, suggesting that they evolved in distant ancestral species. As children master symbolic systems such as maps and language, they come productively to combine representations from the two core systems of geometry in uniquely human ways; these combinations may give rise to abstract geometric intuitions. Studies of the ontogenetic and phylogenetic sources of abstract geometry therefore are illuminating of both human and animal cognition. Research on animals brings simpler model systems and richer empirical methods to bear on the analysis of abstract concepts in human minds. In return, research on humans, relating core cognitive capacities to symbolic abilities, sheds light on the content of representations in animal minds.

Spelke, Elizabeth S.; Lee, Sang Ah

2012-01-01

69

Communications satellite system for Africa  

NASA Astrophysics Data System (ADS)

Earlier established requirement estimations were improved upon by contacting African administrations and organizations. An enormous demand is shown to exist for telephony and teletype services in rural areas. It is shown that educational television broadcasting should be realized in the current African transport and communications decade (1978-1987). Radio broadcasting is proposed in order to overcome illiteracy and to improve educational levels. The technical and commercial feasibility of the system is provided by computer simulations which demonstrate how the required objectives can be fulfilled in conjunction with ground networks.

Kriegl, W.; Laufenberg, W.

1980-09-01

70

ISS Update: High Rate Communications System  

NASA Video Gallery

ISS Update Commentator Pat Ryan interviews Diego Serna, Communications and Tracking Officer, about the High Rate Communications System. Questions? Ask us on Twitter @NASA_Johnson and include the ha...

71

Control Perspective on Communication Using Chaotic Systems.  

National Technical Information Service (NTIS)

Secure communication using chaotic systems is considered from a control point of view. It is shown that a synchronization-based scheme for secure communication described in the literature may in fact be interpreted as an adaptive identification scheme. Tw...

H. J. Huijberts R. Nijmeijer R. M. A. Willems

1998-01-01

72

Digestive Systems in Different Animals  

NSDL National Science Digital Library

From the ThinkQuest Library archives, the fifth site - titled La Casa de Comida - was created by a team of high school students for elementary school children. This section of the site offers a brief and basic comparison of digestive systems in birds, horses, insects, snakes, crustaceans, and mollusks.

1969-12-31

73

Picture archiving and communication systems.  

PubMed

Picture archiving and communication systems (PACS) are extremely versatile systems that facilitate the transfer of digital images and patient data throughout a healthcare enterprise. PACS are most commonly used in radiology departments to process images from diagnostic imaging modalities, such as digital radiography devices and magnetic resonance imaging (MRI) systems. In this article, we evaluate three such systems from three of the largest PACS suppliers--the Agfa IMPAX, GE PathSpeed, and Siemens Sienet. The ultimate goal of any PACS is to improve workflow within the enterprise. Our testing focused on whether, and to what degree, the systems could meet this goal. We found that all three PACS are fairly complete and able to support image distribution and improve workflow compared with film-based processes. However, we did identify significant differences--along with some noteworthy limitations--with respect to system design and operation, external integration capabilities, and supplier support and professional services. We have ranked the systems for each of these factors to help healthcare facilities identify the system that will best meet their needs. Also in this Evaluation, we present an overview of the technology, a Glossary of PACS terminology (see page 400), selection guidance, and discussions of PACS-related topics, including data compression options, the role of the DICOM standard, and concerns about data security in many of today's systems. PMID:11126821

2000-11-01

74

A Reconfigurable Communications System for Small Spacecraft  

NASA Technical Reports Server (NTRS)

Two trends of NASA missions are the use of multiple small spacecraft and the development of an integrated space network. To achieve these goals, a robust and agile communications system is needed. Advancements in field programmable gate array (FPGA) technology have made it possible to incorporate major communication and network functionalities in FPGA chips; thus this technology has great potential as the basis for a reconfigurable communications system. This report discusses the requirements of future space communications, reviews relevant issues, and proposes a methodology to design and construct a reconfigurable communications system for small scientific spacecraft.

Chu, Pong P.; Kifle, Muli

2004-01-01

75

A communication system using magnetic fields  

Microsoft Academic Search

A new wireless communication system using a low frequency signal transmitted by current loop antennas is proposed. The communication range is relatively small (about several meters) so that the range is included in near field of a carrier signal. The use of magnetic fields makes it possible to provide high quality communication in an unfavorable environment where metal or fluids

Yun-Jae Won; Shin-Jae Kang; Sun-Hee Kim; David Choi; Seung-Ok Lim

2009-01-01

76

Spacecraft Multiple Array Communication System Performance Analysis  

NASA Technical Reports Server (NTRS)

The Communication Systems Simulation Laboratory (CSSL) at the NASA Johnson Space Center is tasked to perform spacecraft and ground network communication system simulations, design validation, and performance verification. The CSSL has developed simulation tools that model spacecraft communication systems and the space and ground environment in which the tools operate. In this paper, a spacecraft communication system with multiple arrays is simulated. Multiple array combined technique is used to increase the radio frequency coverage and data rate performance. The technique is to achieve phase coherence among the phased arrays to combine the signals at the targeting receiver constructively. There are many technical challenges in spacecraft integration with a high transmit power communication system. The array combining technique can improve the communication system data rate and coverage performances without increasing the system transmit power requirements. Example simulation results indicate significant performance improvement can be achieved with phase coherence implementation.

Hwu, Shian U.; Desilva, Kanishka; Sham, Catherine C.

2010-01-01

77

Space Shuttle communications and tracking system  

NASA Technical Reports Server (NTRS)

This paper is intended to provide a comprehensive description of the Space Shuttle communications and tracking system design, development, and system operations. Areas of special innovative communications techniques implemented by the Space Shuttle such as source encoding, channel encoding, spread spectrum, and digital modulation are emphasized. In addition, the role of the Electronics Systems Test Laboratory in the development of the system is discussed.

Tu, Kwei; Cravey, Donald N.; Kuo, Yeng S.; Johnson, John H.; Teasdale, William E.

1987-01-01

78

Communications and control for electric power systems  

Microsoft Academic Search

The first section of the report describes the AbNET system, a hardware and software communications system designed for distribution automation (it can also find application in substation monitoring and control). The topology of the power system fixes the topology of the communications network, which can therefore be expected to include a larger number of branch points, tap points, and interconnections.

H. Kirkham; A. Goettsche; D. Niebur; H. Friend; A. Johnston

1991-01-01

79

A Future of Communication Theory: Systems Theory.  

ERIC Educational Resources Information Center

Concepts of general systems theory, cybernetics and the like may provide the methodology for communication theory to move from a level of technology to a level of pure science. It was the purpose of this paper to (1) demonstrate the necessity of applying systems theory to the construction of communication theory, (2) review relevant systems

Lindsey, Georg N.

80

COSMOS: a codesign approach for communicating systems  

Microsoft Academic Search

This paper presents COSMOS, a method for modeling and synthesis of complex communicating systems. COSMOS starts from a system-level specification based on an extended finite state machine model allowing for the specification of complex protocols. System-level synthesis is composed of three tasks: partitioning systems into inter-dependent sub-systems, inter-sub-system communication synthesis and architecture generation. The output is a flexible architecture model

Tarek Ben Ismail; Mohamed Abid; Ahmed Amine Jerraya

1994-01-01

81

The Roles of Mental Animations and External Animations in Understanding Mechanical Systems  

Microsoft Academic Search

The effects of computer animations and mental animation on people's mental mod- els of a mechanical system are examined. In 3 experiments, students learned how a mechanical system works from various instructional treatments including viewing a static diagram of the machine, predicting motion from static diagrams, viewing computer animations, and viewing static and animated diagrams accompanied by verbal commentaries. Although

Mary Hegarty; Sarah Kriz; Christina Cate

2003-01-01

82

Multivariate classification of animal communication signals: A simulation-based comparison of alternative signal processing procedures using electric fishes  

Microsoft Academic Search

Evolutionary studies of communication can benefit from classification procedures that allow individual animals to be assigned to groups (e.g. species) on the basis of high-dimension data representing their signals. Prior to classification, signals are usually transformed by a signal processing procedure into structural features. Applications of these signal processing procedures to animal communication have been largely restricted to the manual

William G. R. Crampton; Justin K. Davis; Nathan R. Lovejoy; Marianna Pensky

2008-01-01

83

Rewiring Your Organization's Learning and Communication System.  

ERIC Educational Resources Information Center

Discusses how to improve an organization's training and communications system, both philosophically and technically, and highlights activities conducive to a rewired communication system. Lists online sources on the topic and freeware packages that can be downloaded, and includes job aid forms designed to be copied and posted in the organization.…

Gayeski, Diane

1997-01-01

84

A Wireless Communications Systems Laboratory Course  

ERIC Educational Resources Information Center

A novel wireless communications systems laboratory course is introduced. The course teaches students how to design, test, and simulate wireless systems using modern instrumentation and computer-aided design (CAD) software. One of the objectives of the course is to help students understand the theoretical concepts behind wireless communication

Guzelgoz, Sabih; Arslan, Huseyin

2010-01-01

85

Communication Architectures for System-on-Chip  

Microsoft Academic Search

Abstract: The analysis of the communication architecture and its associated synthesis process has grown in importance in the era of System-On-Chip devices, since one is moving towards more complex systems, made by several processing elements (cores), with heterogeneous behavior. In many cases, the choice for a communication architecture can be the most crucial factor to meet design constraints. This work

Miircio E. Kreutz; Luigi Carro; Cesar A. Zeferino; Altamiro A. Susin

2001-01-01

86

Organization of Communication in Information Systems.  

ERIC Educational Resources Information Center

Organization of communication between the center of an automated system of information exchange and the subscribers to the system is described. The three requirements are: (1) those technical communication means must be chosen which will provide effective and convenient avenues for calls from the subscribers to the center, (2) the required…

Datsenko, V. P.; Zaytsev, N. G.

87

Communications Interface Driver (CID) System User's Manual.  

National Technical Information Service (NTIS)

This user's manual for the Communications Interface Driver (CID) systems is used to describe the operating procedures of the CID. The CID system is a test tool intended to supply or receive a capacity level of communications messages to and from the air t...

T. Bratton C. Dudas M. Schoenthal J. Davis A. Leone

1989-01-01

88

Towards a seamless hybrid communication system  

NASA Astrophysics Data System (ADS)

By synergistically capitalizing emerging communication technologies from both the RF and the optical domains, this paper proposes a hybrid system architecture by leveraging the emerging programmable/cognitive radio technology and free space optical communication. We identify some key research issues to enable such a system with high data rate, mobility and ubiquitous coverage, and heterogeneous QoS support.

Ye, Yinghua; Zang, Hui

2009-11-01

89

Ant colony system with communication strategies  

Microsoft Academic Search

In this paper an ant colony system (ACS) with communication strategies is devel- oped. The artificial ants are partitioned into several groups. Seven communication methods for updating the pheromone level between groups in ACS are proposed and work on the traveling salesman problem using our system is presented. Experimental results based on three well-known traveling salesman data sets demonstrate the

Shu-chuan Chu; John F. Roddick; Jeng-shyang Pan

2004-01-01

90

Advances in Small Animal Imaging Systems  

NASA Astrophysics Data System (ADS)

The rapid growth in genetics and molecular biology combined with the development of techniques for genetically engineering small animals has led to an increased interest in in vivo laboratory animal imaging during the past few years. For this purpose, new instrumentation, data acquisition strategies, and image processing and reconstruction techniques are being developed, researched and evaluated. The aim of this article is to give a short overview of the state of the art technologies for high resolution and high sensitivity molecular imaging techniques, primarily positron emission tomography (PET) and single photon emission computed tomography (SPECT). The basic needs of small animal imaging will be described. The evolution in instrumentation in the past two decades, as well as the commercially available systems will be overviewed. Finally, the new trends in detector technology and preliminary results from challenging applications will be presented. For more details a number of references are provided.

Loudos, George K.

2007-11-01

91

Data warehouse for assessing animal health, welfare, risk management and -communication  

PubMed Central

The objective of this paper is to give an overview of existing databases in Denmark and describe some of the most important of these in relation to establishment of the Danish Veterinary and Food Administrations’ veterinary data warehouse. The purpose of the data warehouse and possible use of the data are described. Finally, sharing of data and validity of data is discussed. There are databases in other countries describing animal husbandry and veterinary antimicrobial consumption, but Denmark will be the first country relating all data concerning animal husbandry, -health and -welfare in Danish production animals to each other in a data warehouse. Moreover, creating access to these data for researchers and authorities will hopefully result in easier and more substantial risk based control, risk management and risk communication by the authorities and access to data for researchers for epidemiological studies in animal health and welfare.

2011-01-01

92

An animal model of the interpersonal communication of interoceptive (private) states.  

PubMed Central

Pigeons were taught to interact communicatively (i.e., exchange discriminative stimuli) based on 1 pigeon's internal state, which varied as a function of cocaine, pentobarbital, and saline administration. These performances generalized to untrained pharmacological agents (d-amphetamine and chlordiazepoxide) and were observed in the absence of aversive stimulation, deprivation, and unconditioned reinforcement. The training procedure used in this study appears similar to that by which humans learn to report on (tact) their internal environments and may be construed as a rudimentary animal model of the interpersonal communication of private events.

Lubinski, D; Thompson, T

1987-01-01

93

A satellite communications system for electric utilities  

NASA Technical Reports Server (NTRS)

This paper presents the results of a study into the feasibility of using satellite communications for a country-wide system of electric distribution system monitoring and control. The concept selected for study involves the use of a geostationary satellite with a large multi-beam antenna to provide a major part of the communications and control network between participating utilities and various elements of their power distribution networks, including customer loads. Electric utility communications requirements are projected through 1995 in order to size the required capacity of the system. Two basic systems are examined: a one-way system for load control, and a two-way system for distribution system monitoring and control, including customer meter reading. An operating protocol is proposed for each system. Preliminary cost estimates are identified element by element. Finally, expansion of the basic system to include a set of ancillary communications functions is briefly discussed.

Vaisnys, A.; Bergen, L.

1980-01-01

94

Network Management in an Emergency Communications System.  

National Technical Information Service (NTIS)

This thesis begins with a synopsis of contemporary knowledge concerning network management as it has been implemented in a modern communications network, and as it has been postulated by experts in the fields of systems engineering and systems management....

R. L. DeLorey

1986-01-01

95

Radiation-hardened microwave communications system.  

National Technical Information Service (NTIS)

To develop a wireless communication system to meet the stringent requirements for a nuclear hot cell and similar environments, including control of advanced servomanipulators, a microwave signal transmission system development program was established to p...

S. F. Smith D. W. Bible R. I. Crutcher J. H. Hannah J. A. Moore

1993-01-01

96

Improved protection for alarm communications systems.  

National Technical Information Service (NTIS)

Sandia National Laboratories has initiated efforts to identify systems and concepts which are promising for enhanced protection of the alarm communications system against both the insider and outsider adversary. Modules from commercial vendors are being d...

C. D. Jaeger A. Y. Liang

1991-01-01

97

A Millimetre communication system for IVC  

Microsoft Academic Search

Millimetre-wave devices for intelligent transport systems (ITS) are among the research topics for road-vehicle communications (RVC) and inter-vehicle communications (IVC). Up to now, the only commercialized millimetre wave ITS devices are automotive cruise control radars (ACC), as those manufactured in France by Autocruise Company. The idea which we are working on is to implement a communication function on the AC20

I. Yattoun; T. Labia; A. Peden; G. Landrac; M. Ney; M. Resibois; J. M. Bonnin; A. Baghdadi; N. Montavont; M. Fujise; Y. Le Roux

2007-01-01

98

A Distributed Logistic Support Communication System  

Microsoft Academic Search

Abstract: This paper presents a communication architecture to provide an optimizedsupport for communication within a logistic company. Truckage companiesneed continuous and up-to-date information about their business processes in orderto respond quickly to customers' needs and problems emerging during transportprocesses. A reliable and user-friendly communication system is required, whichimproves the relationship between drivers and dispatchers. The main goals areintegration with legacy

V. Gruhn; M. Hlder; R. Ijioui; F. m Schleif; L. Schpe

2003-01-01

99

Collaborative Networked Communication: MUDs as Systems Tools  

Microsoft Academic Search

A systems administration group is only as effective as its internal communication mechanisms. On-line communication has traditionally been managed via electronic mail or news, which are neither real-time nor truly collaborative. Communication tools which let multiple parties work together in real-time have become widespread on the Internet in the last several years. In an effort to keep a physically disjoint

Rémy Evard

1993-01-01

100

Millimeter-wave personal satellite communication system  

NASA Astrophysics Data System (ADS)

This paper describes the system concept of a millimeter-wave personal satellite communication, which includes the configuration of the communication system, the satellite system, and the earth terminal system. The system has a large channel capacity and achieves high performance through a flexible channel set-up method, efficient frequency reuse, and onboard communication equipment such as a baseband channel switching processor and a modulator and demodulator (Modem). Two examples of communication systems are shown, in which the information bit rate, the number of multi-beams, and the antenna diameters are different. On the assumption that a 2 ton class satellite will be used, rough estimates are made of the size, weight, and power consumption of the onboard communication system and bus system of the satellite. In addition, details are given regarding the specifications and performance of trial productions of communication equipment such as the switching processor, the Modem, the TWTA, and the LNA. Finally, the key technical issues for establishing a millimeter-wave personal satellite communication system are also discussed.

Kashiki, Kanshiro; Kuri, Takaki; Maruyama, Hideyuki; Kikuchi, Takaaki; Yamamoto, Tetsuo

1993-10-01

101

Millimeter-wave personal satellite communication system  

NASA Astrophysics Data System (ADS)

This paper describes the system concept of a millimeter-wave personal satellite communication, which includes the configuration of the communication system, the satellite system, and the earth terminal system. The system has a large channel capacity and achieves high performance through a flexible channel set-up method, efficient frequency reuse, and onboard communication equipment such as a baseband channel switching processor and a modulator and demodulator (Modem). Two examples of communication systems are shown, in which the information bit rate, the number of multi-beams, and the antenna diameters are different. On the assumption that a 2 ton class satellite will be used, rough estimates are made of the size, weight, and power consumption of the onboard communication system and bus system of the satellite. In addition, details are given regarding the specifications and performance of trial productions of communication equipment such as the switching processor, the Modem, the TWTA, and the LNA. Finally, the key technical issues for establishing a millimeter-wave personal satellite communication system are also discussed.

Kashiki, Kanshiro; Kuri, Takaki; Maruyama, Hideyuki; Kikuchi, Takaaki; Yamamoto, Tetsuo

102

Integrated Tactical Communications System. Task V. Candidate Mid-Range Communication Systems. Volume III. Appendixes.  

National Technical Information Service (NTIS)

Contents: CP communications alternatives; Demand assigned TDMA TACSATCOM system; Tactical satellite communications for special ammunition storage; Cost constraint analysis; INTAC C-E assets addendum to October 1974 task IV appendix C; Audit trails; INTACS...

1975-01-01

103

Economics of satellite communications systems  

NASA Astrophysics Data System (ADS)

This paper is partly a tutorial, telling systematically how one goes about calculating the total annual costs of a satellite communications system, and partly the expression of some original ideas on the choice of parameters so as to minimize these costs. The calculation of costs can be divided into two broad categories. The first is technical and is concerned with estimating what particular equipment will cost and what will be the annual expense to maintain and operate it. One starts in the estimation of any new system by listing the principal items of equipment, such as satellites, earth stations of various sizes and functions, telemetry and tracking equipment and terrestrial interfaces, and then estimating how much each item will cost. Methods are presented for generating such estimates, based on a knowledge of the gross parameters, such as antenna size, coverage area, transmitter power and information rate. These parameters determine the system performance and it is usually possible, knowing them, to estimate the costs of the equipment rather well. Some formulae based on regression analyses are presented. Methods are then given for estimating closely related expenses, such as maintenance and operation, and then an approximate method is developed for estimating terrestrial interconnection costs. It is pointed out that in specific cases when tariff and geographical information are available, it is usually better to work with specific data, but nonetheless it is often desirable, especially in global system estimating, to approximate these interconnect costs without recourse to individual tariffs. The procedure results in a set of costs for the purchase of equipment and its maintenance, and a schedule of payments. Some payments will be incurred during the manufacture of the satellite and before any systems operation, but many will not be incurred until the system is no longer in use, e.g. incentives. In any case, with the methods presented in the first section, one arrives at a schedule of costs and payments for all the items and the years in which they will be incurred. The second category of costing problems is one of financing or engineering economics. All the costs are first "present valued" to some reference period using rates of return appropriate to the particular situation. One finally arrives at sets of annual costs which can be used as the basis for setting lease costs or revenue requirements and tariffs. The correspondence between methods using discounted rates of return and capital recovery formulae on one hand and those using various depreciation schedules, such as is typical of regulated industries on the other hand, is discussed. The remainder of the paper is devoted to discussing the relationship between critical parameters, such as replacement schedules, design lifetime, satellite power and Earth station antenna size, and the overall costs. It is shown that optima for these parameters may exist and can be calculated. In particular, the optimization of satellite replacement schedules to minimize the present value of total investment over a very long period is presented, along with simplified versions of the theory suitable for system planning. The choice of EIRP is also discussed and a procedure for choosing the value that minimizes the costs is shown.

Pritchard, Wilbur L.

104

A 1000+ channel bionic communication system.  

PubMed

The wireless electronic nervous system interface known as the functional electrical stimulation-battery powered bion system is being developed at the Alfred Mann Foundation. It contains a real-time propagated wave micro-powered multichannel communication system. This system is designed to send bi-directional messages between an external master controller unit (MCU), and each one of a group of injectable stimulator-sensor battery powered bion implants (BPB). The system is capable of communicating in each direction about 90 times per second using a structure of 850 time slots within a repeating 11 millisecond time window. The system's total Time Division Multiple Access (TDMA) communication capability is about 77,000 two-way communications per second on a single 5 MHz wide radio channel. Each time slot can be used by one BPB, or shared alternately by two or more BPBs. Each bidirectional communication consists of a 15 data bit message sent from the MCU sequentially to each BPB and 10 data bit message sent sequentially from each BPB to the MCU. Redundancy bits are included to provide error detection and correction. This communication system is designed to draw only a few microamps from the 3.6 volt, 3.0 mAHr lithium ion (LiIon) battery contained in each BPB, and the majority of the communications circuitry is contained within a 1.4x5 mm integrated circuit. PMID:17947078

Schulman, Joseph H; Mobley, J Phil; Wolfe, James; Stover, Howard; Krag, Adrian

2006-01-01

105

How to Bootstrap a Human Communication System  

ERIC Educational Resources Information Center

How might a human communication system be bootstrapped in the absence of conventional language? We argue that motivated signs play an important role (i.e., signs that are linked to meaning by structural resemblance or by natural association). An experimental study is then reported in which participants try to communicate a range of pre-specified…

Fay, Nicolas; Arbib, Michael; Garrod, Simon

2013-01-01

106

Tags, wireless communication systems, tag communication methods, and wireless communications methods  

DOEpatents

Tags, wireless communication systems, tag communication methods, and wireless communications methods are described. In one aspect, a tag includes a plurality of antennas configured to receive a plurality of first wireless communication signals comprising data from a reader, a plurality of rectifying circuits coupled with. respective individual ones of the antennas and configured to provide rectified signals corresponding to the first wireless communication signals, wherein the rectified signals are combined to produce a composite signal, an adaptive reference circuit configured to vary a reference signal responsive to the composite signal, a comparator coupled with the adaptive reference circuit and the rectifying circuits and configured to compare the composite signal with respect to the reference signal and to output the data responsive to the comparison, and processing circuitry configured to receive the data from the comparator and to process the data.

Scott; Jeff W. (Pasco, WA), Pratt; Richard M. (Richland, WA)

2006-09-12

107

Preliminary Thoughts on Netted Cable Communication Systems.  

ERIC Educational Resources Information Center

There are five categories of cable communication systems: Conventional Community Antenna Television (CATV), Pay-TV, Subscriber Response Systems, Electronic Information Handling Systems, and Two-Way Audio/Visual Systems. CATV and Pay-TV systems are designed for the one-way transmission of programs, the former providing for better quality…

Eldridge, Frank; Mason, William

108

Voice communication research and evaluation system  

NASA Astrophysics Data System (ADS)

The basic system is comprised of a multistation voice communication network consisting of the USAF standard aircraft intercommunication system, a standard A-19 diluter demand oxygen regulation system and an on line computer data collection and data analysis system that displays results in real time. The system is housed in a large reverberation chamber containing a programmable sound source capable of reproducing the spectrum and level of any AF operational noise environment. Standardized voice communication effectiveness test materials are used to assess the performance of any aspect of the total voice communication link, however, emphasis is usually placed upon the performance of the aircrew members. Examples of its application to voice communication problems are provided.

McKinley, R. L.

1981-06-01

109

Molecular communication: Harnessing biochemical materials to engineer biomimetic communication systems  

Microsoft Academic Search

Molecular communication uses molecules (i.e., biochemical signals) as an information medium and allows biologically and artificially created nano- or microscale entities to communicate over a short distance. It is a new communication paradigm; it is different from the traditional communication paradigm, which uses electromagnetic waves (i.e., electronic and optical signals) as an information medium. Key research challenges in molecular communication

Satoshi Hiyama; Yuki Moritani

2010-01-01

110

Automobile inspection system based on wireless communication  

NASA Astrophysics Data System (ADS)

This paper aims to research the Automobile Inspection System based on Wireless Communication, and suggests an overall design scheme which uses GPS for speed detection and Bluetooth and GPRS for communication. The communication between PDA and PC was realized by means of GPRS and TCP/IP; and the hardware circuit and software for detection terminal were devised by means of JINOU-3264 Bluetooth Module after analyzing the Bluetooth and its communication protocol. According to the results of debugging test, this system accomplished GPRS based data communication and management as well as the real-time detection on auto safety performance parameters in crash test via PC, whereby the need for mobility and reliability was met and the efficiency and level of detection was improved.

Miao, Changyun; Ye, Chunqing

2010-07-01

111

Unique features of animal mitochondrial translation systems  

PubMed Central

In animal mitochondria, several codons are non-universal and their meanings differ depending on the species. In addition, the tRNA structures that decipher codons are sometimes unusually truncated. These features seem to be related to the shortening of mitochondrial (mt) genomes, which occurred during the evolution of mitochondria. These organelles probably originated from the endosymbiosis of an aerobic eubacterium into an ancestral eukaryote. It is plausible that these events brought about the various characteristic features of animal mt translation systems, such as genetic code variations, unusually truncated tRNA and rRNA structures, unilateral tRNA recognition mechanisms by aminoacyl-tRNA synthetases, elongation factors and ribosomes, and compensation for RNA deficits by enlarged proteins. In this article, we discuss molecular mechanisms for these phenomena. Finally, we describe human mt diseases that are caused by modification defects in mt tRNAs.

Watanabe, Kimitsuna

2010-01-01

112

Scripting Affective Communication with Life-Like Characters in Web-Based Interaction Systems  

Microsoft Academic Search

In this paper, we discuss scripting tools that aim at facilitating the design of web-based interactions with animated characters capable of afiective communication. Speciflcally, two systems are developed. The SCREAM system is a scripting tool that enables au- thors to create emotionally and socially appropriate responses of animated characters. Content authors may design the mental make-up of a character by

Helmut Prendinger; Sylvain Descamps; Mitsuru Ishizuka

2002-01-01

113

Energy-aware portable video communication system design for wildlife activity monitoring  

Microsoft Academic Search

In this paper, we introduce our recent research and development effort on energy-efficient portable video communication system design for wildlife activity monitoring. The capability of seeing what an animal sees in the field is very important for wildlife activity monitoring and research. We design an integrated video and sensor system, called DeerCam and mount it on animals so as to

Zhihai He; Jay Eggert; Wenye Cheng; Xiwen Zhao; Joshua Millspaugh; Remington Moll; Jeff Beringer; Joel Sartwell

2008-01-01

114

The Roles of Mental Animations and External Animations in Understanding Mechanical Systems  

ERIC Educational Resources Information Center

The effects of computer animations and mental animation on people's mental models of a mechanical system are examined. In 3 experiments, students learned how a mechanical system works from various instructional treatments including viewing a static diagram of the machine, predicting motion from static diagrams, viewing computer animations, and…

Hegarty, Mary; Kriz, Sarah; Cate, Christina

2003-01-01

115

Cyclostationary Signal Processing in Digital Communication Systems.  

National Technical Information Service (NTIS)

Our focus in this ARO research project is to investigate and study the application of cyclostationary signal processing in digital communication systems. We consider several important areas of application including channel equalization, co-channel interfe...

Z. Ding

1999-01-01

116

Systems Theory and Communication. Annotated Bibliography.  

ERIC Educational Resources Information Center

This annotated bibliography presents annotations of 31 books and journal articles dealing with systems theory and its relation to organizational communication, marketing, information theory, and cybernetics. Materials were published between 1963 and 1992 and are listed alphabetically by author. (RS)

Covington, William G., Jr.

117

Advanced Semiconductor Devices for Optical Communication Systems.  

National Technical Information Service (NTIS)

The paper describes high-speed distributed feedback laser diodes (DFB-LDs), heterobipolar transistors (HBTs), and optoelectronic integrated circuits (OEICs), all of which are key semiconductor devices used in the high-speed optical communication systems r...

M. Nakamura M. Obara

1989-01-01

118

Nutrition Implementation Programs as Communication Systems  

ERIC Educational Resources Information Center

Description of a model nutrition implementation program as a communication system. Focus is on developing countries where, author maintains, there is an over-emphasis on surveys and collection of data. Problems on program implementation are discussed. (LK)

Fugelsang, Andreas

1972-01-01

119

Satellite multiple access systems for mobile communication  

NASA Technical Reports Server (NTRS)

This paper considers multiple access techniques for a mobile radio system which incorporates a geosynchronous orbiting satellite repeater through which mobile terminals communicate. The communication capacities of FDMA, TDMA and CDMA systems are examined for a 4 MHz bandwidth system to serve up to 10,000 users. An FDMA system with multibeam coverage is analyzed in detail. The system includes an order-wire network for demand-access control and reassignment of satellite channels. Satellite and terminal configurations are developed to a block diagram level and system costs and implementation requirements are discussed.

Lewis, J. L.

1979-01-01

120

Geographically distributed multiprocessor time-shared communication processing system  

Microsoft Academic Search

This patent describes a multiprocessor communication processing system for use in a communication or telephone network wherein in the system each processor supports processes, a communication system having communication connections between processes for transferring data in accordance with communication parameters, and means invoked by each process requesting a connection to the other processes in the same and different processors for

G. R. Babecki; F. Kaplan; H. R. Liu; G. F. MacLachlan; J. F. McDonald; J. D. Palframan; M. J. Welt; T. A. Wendt; G. S. Yates

1986-01-01

121

Strategies for encouraging successful adoption of office communication systems  

Microsoft Academic Search

The adoption of new computer communication systems into organizations requires behavioral change. Planning for successful adoption requires knowledge of individual organizational communication patterns and the relationship between those patterns and particular communication system solutions. This paper documents a sequence of studies of organizational communication. Needs for office communication systems were identified, as were social and psychological factors temporarily inhibiting their

Susan F. Ehrlich

1987-01-01

122

Rugged Video System For Inspecting Animal Burrows  

NASA Technical Reports Server (NTRS)

Video system designed for examining interiors of burrows of gopher tortoises, 5 in. (13 cm) in diameter or greater, to depth of 18 ft. (about 5.5 m), includes video camera, video cassette recorder (VCR), television monitor, control unit, and power supply, all carried in backpack. Polyvinyl chloride (PVC) poles used to maneuver camera into (and out of) burrows, stiff enough to push camera into burrow, but flexible enough to bend around curves. Adult tortoises and other burrow inhabitants observable, young tortoises and such small animals as mice obscured by sand or debris.

Triandafils, Dick; Maples, Art; Breininger, Dave

1992-01-01

123

[Develop mine communications system]. Final technical report  

SciTech Connect

The objective of this project was to develop, design, and build a system prototype to demonstrate the practicality of two-way, wireless through-the-earth communications between the interior of a mine and the surface. The system was to communicate data for process and environment monitoring and control, and provide real-time voice communication for emergency situations and for daily operations use. Transmitters and receivers were designed, built, and tested in actual mines. A wireless in-mine communications system was also developed. The feasibility of the concept and the marketability of the product were successfully demonstrated. Additional work must be done to make the product suitable for, and marketable to, the coal mining industry.

Meiksin, Z.H.

1998-09-15

124

Design for communications center monitor & control system  

Microsoft Academic Search

Communications center monitor & control system, including power supply sub-system, environment sub-system, fire sub-system, security sub-system and so on, is widely used in school, enterprise, government and other areas. The control system designed by this paper can get temperature and humidity information from RS485 sensor of temperature-humidity. From measuring gate sensor, smoke sensor and leak-water senor, the control system can

Zhigang Lv; Cuixia Liu

2010-01-01

125

Simultaneous use of different communication mechanisms leads to spatial sorting and unexpected collective behaviours in animal groups.  

PubMed

Communication among individuals forms the basis of social interactions in every animal population. In general, communication is influenced by the physiological and psychological constraints of each individual, and in large aggregations this means differences in the reception and emission of communication signals. However, studies on the formation and movement of animal aggregations usually assume that all individuals communicate with neighbours in the same manner. Here, we take a new approach on animal aggregations and use a nonlocal mathematical model to investigate theoretically the simultaneous use of two communication mechanisms by different members of a population. We show that the use of multiple communication mechanisms can lead to behaviours that are not necessarily predicted by the behaviour of subpopulations that use only one communication mechanism. In particular, we show that while the use of one communication mechanism by the entire population leads to deterministic movement, the use of multiple communication mechanisms can lead in some cases to chaotic movement. Finally, we show that the use of multiple communication mechanisms leads to the sorting of individuals inside aggregations: individuals that are aware of the location and the movement direction of all their neighbours usually position themselves at the centre of the groups, while individuals that are aware of the location and the movement direction of only some neighbours position themselves at the edges of the groups. PMID:23938233

Eftimie, Raluca

2013-11-21

126

Molecular Communication - A Biochemically-Engineered Communication System  

Microsoft Academic Search

Molecular communication uses molecules (i.e., chemical signals) as an information carrier and allows biological and artificially-created nano- or cell-scale devices to communicate over a short distance. It is a new communication paradigm and is different from the existing communication paradigm that uses electromagnetic waves (i.e., electronic and optical signals) as an information carrier. Key research challenges in molecular communication include

Yuki Moritani; Satoshi Hiyama; Tatsuya Suda

2007-01-01

127

Security Communication Systems for Nuclear Fixed Site Facilities.  

National Technical Information Service (NTIS)

This report presents a basic discussion of communication techniques and factors relevant to designing communication systems for nuclear fixed site facility security systems. The reader is provided communication fundamentals, design considerations, and spe...

L. C. Howington L. L. Taylor

1980-01-01

128

Full-duplex optical communication system  

NASA Technical Reports Server (NTRS)

A method of full-duplex electromagnetic communication wherein a pair of data modulation formats are selected for the forward and return data links respectively such that the forward data electro-magnetic beam serves as a carrier for the return data. A method of encoding optical information is used wherein right-hand and left-hand circular polarizations are assigned to optical information to represent binary states. An application for an earth to low earth orbit optical communications system is presented which implements the full-duplex communication and circular polarization keying modulation format.

Shay, Thomas M. (Inventor); Hazzard, David A. (Inventor); Horan, Stephen (Inventor); Payne, Jason A. (Inventor)

2004-01-01

129

Analysis of maritime mobile satellite communication systems  

NASA Astrophysics Data System (ADS)

The communication channel between a satellite and a ship earth station (SES) is described by a model which includes multipath fading, Doppler shift and noise. Multipath fading is caused by reflections from the sea surface. These reflections can affect the system performance, especially at low elevation angles or when SES is using low gain antennas. Doppler shift is a very important effect when using low altitude satellites, because of the high velocities involved. A software simulator is described and a simulator is presented for multipath fading in the maritime communications environment. Analysis of throughput of an unslotted Aloha maritime mobile satellite communication channel is also presented.

Zapata, Augusto J.

1988-12-01

130

Iterative design of video communication systems  

Microsoft Academic Search

This paper reviews the design and implementation of several video telephony systems at Bellcore as a case study in iterative design. In contrast to single user compuer applications, communication systems consists of both the interconnection technology and the people who are interconnected. From a user’s point of view, the capabilities provided by the system, the rules for its use, and

Colleen Cool; Robert S. Fish; Robert E. Kraut; C. M. Lowery

1992-01-01

131

Scout: a communications-oriented operating system  

Microsoft Academic Search

Scout is new communication-centric operating system. The principle scout abstraction (the path) is an attempt to capture all of the operating system infrastructure necessary to insure that a given network connection can achieve high and predictable performance in the face of other connections and other system loads

Allen B. Montz; David Mosberger; S. W. O'Mally; Larry L. Peterson; Todd A. Proebsting

1995-01-01

132

A high sensitivity small animal SPECT system  

PubMed Central

Medical imaging using single gamma ray emitting radionuclides typically makes use of parallel hole collimators or pinholes in order to achieve good spatial resolution. However, a tradeoff in sensitivity is inherent in the use of a collimator, and modern preclinical SPECT (single photon emission computed tomography) systems detect a very small fraction of emitted gamma rays, often less than 0.1%. A system for small animal SPECT imaging which uses no collimators could potentially achieve very high sensitivity—several tens of percent—with reasonably sized detectors. This would allow two significant improvements in preclinical studies: images could be obtained more rapidly, allowing higher throughput for screening applications, or for dynamic processes to be observed with very good time resolution; and images could be obtained with less radioactive tracer, making possible the in vivo imaging of low-capacity receptor systems, aiding research into new tracer compounds, and reducing the cost and easing the regulatory burden of an experiment. Of course, a system with no collimator will not be able to approach the sub-millimeter spatial resolutions produced by the most advanced pinhole and collimated systems, but a high sensitivity system with resolution of order one centimeter could nonetheless find significant and new use in the many molecular imaging applications which do not require good spatial resolution—for example, screening applications for drug development or new imaging agents. Rather than as an alternative to high resolution SPECT systems, the high sensitivity system is proposed as a radiotracer alternative to optical imaging for small animals. We have developed a prototype system for mouse imaging applications. The scanner consists of two large, thin, closely spaced scintillation detectors. Simulation studies indicate that a FWHM spatial resolution of 7 mm is possible. In an in vivo mouse imaging study using the 99mTc labeled tracer MAG-3, the sensitivity of the system is measured to be 40%. Simple projection images created by analytically combining the two detectors' data show sufficient resolution to observe the dynamic distribution of the radiotracer in the mouse.

Mitchell, Gregory S; Cherry, Simon R

2009-01-01

133

Interactive communications systems simulation model (ICSSM)  

NASA Astrophysics Data System (ADS)

The Interactive Communication Systems Simulation Model (ICSSM) developed for Rome Air Development Center is capable of simulating a point-to-point communication system including its functional elements, components, propagation effects, and transmission media. The ICSSM is a flexible, expandable, sophisticated and easy-to-use computerized means to develop or configure communication system specific simulation models; specify and validate system requirements; evaluate new techniques and assess the performance of existing and proposed conventional and ECCM communications systems and equipment. The ICSSM's preconfigured programming structure frees the analyst from the burden of constructing a special simulation framework for each model effort, thus permitting him to concentrate on the model formulation itself. Further, the analyst may benefit from the legacy of previous modeling via the ICSSM library of communication model elements which are supported by computerized tutorials and guides. The development of the initial ICSSM concentrated on efficient system structure, a generalized simulation capability and on making the system easy to use. The ICSSM increases in utility with continued use as additional modeling elements are incorporated in the expandable library.

Paolicelli, J.; Griese, W. F.

1980-12-01

134

Interactive communication systems simulation model (ICSSM) extension  

NASA Astrophysics Data System (ADS)

The Interactive Communication System Simulation Model (ICSSM), developed for the Rome Air Development Center, is capable of simulating a point-to-point communication system including its functional elements, components, propagation effects, and transmission media. The ICSSM is a flexible, expandable, sophisticated and easy-to-use computerized means to develop or configure communication system specific simulation models; specify and validate system requirements; evaluate new techniques and assess the performance of existing and proposed conventional and ECCM communications systems and equipment. The ICSSM's preconfigured programming structure frees the analyst from the burden of constructing a special simulation framework for each model effort, thus permitting him to concentrate on the model formulation itself. Further, the analyst may benefit from the legacy of previous modeling via the ICSSM library of communication model elements which are supported by computerized tutorials and guides. The development of the initial ICSSM concentrated on efficient system structure, a generalized simulation capability and on making the system easy to use. The ICSSM increases in utility with continued use as additional modeling elements are incorporated into the expandable library.

Gerry, I.; Mammone, M.; Wade, W. D.

1983-07-01

135

African satellite communication systems and their implications  

NASA Astrophysics Data System (ADS)

Because of the size of the African continent and the, in general, poor conditions of its communication facilities, a number of solutions involving the use of satellites have been considered. The present investigation is concerned with the Afsat project. This project has been promoted and studied by Eurospace, which represents the Organization of the European Space Industry, founded in 1961. The current situation and needs of communication in Africa are considered along with a feasibility study of the system, the economic aspects, a comparison of Afsat with alternative solutions, and problems of space segment financing and organization. It is concluded that a dedicated African communication satellite system would make a decisive contribution to the improvement of the continent's communications in terms of increased capacity and better availability and quality of circuits.

Demerliac, Y.

1984-07-01

136

Animal biocalorimeter and waste management system  

NASA Technical Reports Server (NTRS)

A biocalorimeter and waste management system is provided for making metabolic heat release measurements of animals or humans in a calorimeter (enclosure) using ambient air as a low velocity source of ventilating air through the enclosure. A shroud forces ventilating air to pass over the enclosure from an end open to ambient air at the end of the enclosure opposite its ventilating air inlet end and closed around the inlet end of the enclosure in order to obviate the need for regulating ambient air temperature. Psychrometers for measuring dry- and wet-bulb temperature of ventilating air make it possible to account for the sensible and latent heat additions to the ventilating air. A waste removal system momentarily recirculates high velocity air in a closed circuit through the calorimeter wherein a sudden rise in moisture is detected in the ventilating air from the outlet.

Poppendiek, Heinz F. (Inventor); Trimailo, William R. (Inventor)

1995-01-01

137

Communication Middleware for Reliable Workflow Management Systems  

Microsoft Academic Search

In distributed workflow management systems (WfMSs) many workflow servers and clients should work together cooperatively using client\\/server communication. Depending on the communication partners, different characteristics are required for a client\\/server interaction. In this paper we introduce a middleware service for WfMSs which supports client\\/server interaction qualities. These qualities characterize the behavior of client and server in case of failure and

Hans Schuster

1996-01-01

138

Early Communication System (ECOMM) for ISS  

NASA Technical Reports Server (NTRS)

The International Space Station (ISS) Early Communications System (ECOMM) was a Johnson Space Center (JSC) Avionic Systems Division (ASD) in-house developed communication system to provide early communications between the ISS and the Mission Control Center-Houston (MCC-H). This system allows for low rate commands (link rate of 6 kbps) to be transmitted through the Tracking and Data Relay Satellite System (TDRSS) from MCC-H to the ISS using TDRSS's S-band Single Access Forward (SSA/) link service. This system also allows for low rate telemetry (link rate of 20.48 kbps) to be transmitted from ISS to MCC-H through the TDRSS using TDRSS's S-band Single Access Return (SSAR) link service. In addition this system supports a JSC developed Onboard Communications Adapter (OCA) that allows for a two-way data exchange of 128 kbps between MCC-H and the ISS through TDRSS. This OCA data can be digital video/audio (two-way videoconference), and/or file transfers, and/or "white board". The key components of the system, the data formats used by the system to insure compatibility with the future ISS S-Band System, as well as how other vehicles may be able to use this system for their needs are discussed in this paper.

Gaylor, Kent; Tu, Kwei

1999-01-01

139

SRS Computer Animation and Drive Train System  

NASA Technical Reports Server (NTRS)

The spinning rocket simulator (SRS) is an ongoing project at Oral Roberts University. The goal of the SRS is to gather crucial data concerning a spinning rocket under thrust for the purpose of analysis and correction of the coning motion experienced by this type of spacecraft maneuver. The computer animation simulates a virtual, scale model of the component of the SRS that represents the spacecraft itself. This component is known as the (VSM), or virtual spacecraft model. During actual physical simulation, this component of the SRS will experience a coning. The goal of the animation is to cone the VSM within that range to accurately represent the motion of the actual simulator. The drive system of the SRS is the apparatus that turns the actual simulator. It consists of a drive motor, motor mount and chain to power the simulator into motion. The motor mount is adjustable and rigid for high torque application. A digital stepper motor controller actuates the main drive motor for linear acceleration. The chain transfers power from the motor to the simulator via sprockets on both ends.

Arthun, Daniel; Schachner, Christian

2001-01-01

140

Crop-animal systems in Asia: future perspectives  

Microsoft Academic Search

In the next two decades, the demand for animal products will more than double. The concluding paper provides some considered predictions on the future for crop-animal systems in Asia, as a consequence of this trend. Although meat and eggs from non-ruminants in industrial systems will continue to be the main source of animal proteins, it is unlikely that these systems

C. Devendra

2002-01-01

141

Communication Theory of Secrecy Systems?  

Microsoft Academic Search

detailed study is made of the many standard types of codes and ciphers, and of the ways of breaking them. We will be more concerned with the general mathematical structure and properties of secrecy systems. The treatment is limited in certain ways. First, there are three general types of secrecy system: (1) concealment systems, including such methods as invisible ink,

C. E. SHANNON

142

Dust inhalation system for small laboratory animals.  

PubMed

In order to stabilize the dust concentration for animal inhalation studies, two feedback systems were introduced. Dusts generated were passed through two cyclone separators and stored first in a storage chamber. Then they were aspirated into an ejector by compressed carrier air, mixed with filtered room air in a mixing box, and introduced into an exposure chamber. The first feedback system was for dust generation. Dusts were reaerosolized by on-off control using the output signals from a light-scattering dust detector connected to a storage chamber. The second system was for the control of compressed carrier air flow into an ejector. Compressed air flow was automatically regulated by a PID-controller in combination with a mass flow controller. The PID-controller processed continuous signals from another dust detector connected to an exposure chamber and fed control signals to a mass flow controller for regulation of the compressed air flow. This automatic control system could not only reduce hunchings of dust concentration following on-off control of a dust generator but also reduce overshooting of dust concentration in the exposure chamber following the detachment and dispersion of dusts adhering to the inner walls of the dust-supplying route. The system could also maintain a desired dust concentration in the exposure chamber for up to 180 days (20 hr/day, 7 days/week). In addition, this system could simultaneously introduce different doses of dust to other exposure chambers stably while maintaining similar size distribution of the dusts if additional identical exposure units were used. These results indicate that this dust inhalation system is suitable both for long-term studies and for investigating a dose-response relationship. PMID:8519290

Negishi, T; Nishimura, I

1993-04-01

143

Second generation picture archiving and communication systems  

Microsoft Academic Search

A modern radiology department utilizes multimedia technologies to facilitate its operation. Multimedia technologies include hardware platform, information systems, databases, communication protocols, display technology and system interface and integration. Current existing PACS can not handle this multimedia information because of its closed architectural design. This paper describes the concept of second generation PACS and its design and implementation at the University

H. K. Huang; Ronald L. Arenson; Shyh-Liang Lou; Albert W. Wong; Katherine P. Andriole; Todd M. Bazzill; David A. Avrin; Robert G. Gould

1994-01-01

144

Communication and Synchronization in Distributed Systems  

Microsoft Academic Search

Recent advances in technology have made the construction of general-purpose systems out of many small independent microprocessors feasible. One of the issue's concerning distributed systems is the question of appropriate language constructs for the handling of communication and synchronization. In his paper, \\

Abraham Silberschatz

1979-01-01

145

Radiation-hardened microwave communications system  

Microsoft Academic Search

To develop a wireless communication system to meet the stringent requirements for a nuclear hot cell and similar environments, including control of advanced servomanipulators, a microwave signal transmission system development program was established to produce a demonstration prototype for the Consolidated Fuel Reprocessing Program at Oak Ridge National Laboratory (ORNL). Proof-of-principle tests in a partially metal lined enclosure at ORNL

S. F. Smith; D. W. Bible; R. I. Crutcher; J. H. Hannah; J. A. Moore; C. H. Nowlin; R. I. Vandermolen; D. Chagnot; A. Leroy

1993-01-01

146

On Variants of Communicating Distributed H Systems  

Microsoft Academic Search

A recent result shows that a variant of communicating distri buted H system with two components can generate recursive enumerable languages. In this variant the filters are a finite union of sets whose number depends upon the simulated system. We prove here that it is possible to obtain the same result usi ng filters testing the presence of couples of

Pierluigi Frisco; Claudio Zandron

2001-01-01

147

Southern Maine's Emergency Medical Communications System.  

National Technical Information Service (NTIS)

A new concept in the coordination of an emergency medical services (EMS) system on both a statewide and local area level is presented in this operations manual. The new system provides a 'Backbone' communications network across the State for requesting an...

1973-01-01

148

Inter-vehicle communication systems: A survey  

Microsoft Academic Search

Inter-vehicle communication (IVC) systems (i.e., systems not relying on roadside infrastructure) have the potential to radically improve the safety, efficiency, and comfort of everyday road travel. Their main advantage is that they bypass the need for expensive infrastructure; their major drawback is the comparatively complex networking protocols and the need for significant penetration before their applications can become effective. In

Mihail L. Sichitiu; Maria Kihl

2008-01-01

149

AN APPROACH FOR NETWORK COMMUNICATIONS SYSTEMS RECOVERY  

Microsoft Academic Search

In this paper we e xamine the problem of f ailures within network communications and telecom systems and outline a localised Invisible Recovery solution to such systems. We introduce a new approach that makes use of an envelope surrounding an unchanged software protocol layer, which is running as an independent process. This envelope stores just sufficient information on each connection

GEORGE G. MITCHELL; STEPHEN BROWN

2000-01-01

150

National Airspace System Communications Operational Concept.  

National Technical Information Service (NTIS)

A requirement for the National Airspace System (NAS) is to provide for communications, as identified in the NAS System Requirement Specification, NAS-SR-1000 (NASSRS). This document presents a concept of operation for air-ground, ground-ground communicati...

H. Nelson, T. Pickerell, W. Trent

1991-01-01

151

Chaotic signals and systems for communications  

Microsoft Academic Search

The authors propose and demonstrate two approaches to communications based on synchronized chaotic signals and systems. In the first approach, a chaotic masking signal is added at the transmitter and regenerated and subtracted at the receiver. The second approach utilizes modulation of the coefficients of the chaotic system in the transmitter and corresponding detection of synchronization error in the receiver

K. M. Cuomo; Alan V. Oppenheim

1993-01-01

152

Digital secure communication via chaotic systems  

Microsoft Academic Search

This paper presents a novel secure communication system for digital signal transmissions. It contains four important parts: modulation, chaotic transmitter, chaotic receiver, and demodulation. The modulation mechanism is to modulate each of delivered bit information to be a carrier signal in the continuous form. Then this carrier signal is taken as a parameter of the chaotic system, called the unified

Wei-Der Chang

2009-01-01

153

Network Security: Synchronization in Chaotic Communication Systems  

Microsoft Academic Search

As the number of communication security violations and the sophistication of intruders and bad actors increases, complex processes such as chaos and quantum theory become applicable to cryptographic systems and to network security. In this paper we demystify chaos and chaotic processes with simple examples; we provide examples of using chaos in cryptographic systems, and we identify synchronization issues in

Stamatios V. Kartalopoulos

2009-01-01

154

Communication Simulations for Power System Applications  

SciTech Connect

New smart grid technologies and concepts, such as dynamic pricing, demand response, dynamic state estimation, and wide area monitoring, protection, and control, are expected to require considerable communication resources. As the cost of retrofit can be high, future power grids will require the integration of high-speed, secure connections with legacy communication systems, while still providing adequate system control and security. While considerable work has been performed to create co-simulators for the power domain with load models and market operations, limited work has been performed in integrating communications directly into a power domain solver. The simulation of communication and power systems will become more important as the two systems become more inter-related. This paper will discuss ongoing work at Pacific Northwest National Laboratory to create a flexible, high-speed power and communication system co-simulator for smart grid applications. The framework for the software will be described, including architecture considerations for modular, high performance computing and large-scale scalability (serialization, load balancing, partitioning, cross-platform support, etc.). The current simulator supports the ns-3 (telecommunications) and GridLAB-D (distribution systems) simulators. Ongoing and future work will be described, including planned future expansions for a traditional transmission solver. A test case using the co-simulator, utilizing a transactive demand response system created for the Olympic Peninsula and AEP gridSMART demonstrations, requiring two-way communication between distributed and centralized market devices, will be used to demonstrate the value and intended purpose of the co-simulation environment.

Fuller, Jason C.; Ciraci, Selim; Daily, Jeffrey A.; Fisher, Andrew R.; Hauer, Matthew L.

2013-05-29

155

NOVANET: communications network for a control system  

SciTech Connect

NOVANET is a control system oriented fiber optic local area network that was designed to meet the unique and often conflicting requirements of the Nova laser control system which will begin operation in 1984. The computers and data acquisition devices that form the distributed control system for a large laser fusion research facility need reliable, high speed communications. Both control/status messages and experimental data must be handled. A subset of NOVANET is currently operating on the two beam Novette laser system.

Hill, J.R.; Severyn, J.R.; VanArsdall, P.J.

1983-05-23

156

A 1000+ Channel Bionic Communication System  

Microsoft Academic Search

The wireless electronic nervous system interface known as the functional electrical stimulation-battery powered bionreg system is being developed at the Alfred Mann Foundation. It contains a real-time propagated wave micro-powered multichannel communication system. This system is designed to send bi-directional messages between an external master controller unit (MCU), and each one of a group of injectable stimulator-sensor battery powered bionreg

Joseph H. Schulman; J. Phil Mobley; James Wolfe; Howard Stover; Adrian Krag

2006-01-01

157

Shuttle payload S-band communications system  

NASA Technical Reports Server (NTRS)

The Shuttle payload S-band communications system design, operational capabilities, and performance are described in detail. System design requirements, overall system and configuration and operation, and laboratory/flight test results are presented. Payload communications requirements development is discussed in terms of evolvement of requirements as well as the resulting technical challenges encountered in meeting the initial requirements. Initial design approaches are described along with cost-saving initiatives that subsequently had to be made. The resulting system implementation that was finally adopted is presented along with a functional description of the system operation. A description of system test results, problems encountered, how the problems were solved, and the system flight experience to date is presented. Finally, a summary of the advancements made and the lessons learned is discussed.

Batson, B. H.; Teasdale, W. E.; Pawlowski, J. F.; Schmidt, O. L.

1985-01-01

158

Polychannel systems for mass digital communication  

NASA Astrophysics Data System (ADS)

We describe a new type of distributed computer system that looks beyond workstation and local area network assumptions towards the time when computers will be used by everyone at both home and the office. This new system is designed to provide sophisticated information services to an entire metropolitan area. We have combined digital broadcast channels and duplex communication channels in a polychannel system that uses predicate based database content labels to automatically route queries. Our thesis is that a polychannel system produces substantial cost and system scaling advantages while retaining the flexibility of client-server style duplex communication. Experimental data from a two year test of the Boson Community Information System system with hundreds of users supports this thesis.

Gifford, David K.

1988-07-01

159

A small terminal for satellite communication systems  

NASA Technical Reports Server (NTRS)

A small portable, low-cost satellite communications terminal system incorporating a modulator/demodulator and convolutional-Viterbi coder/decoder is described. Advances in signal processing and error-correction techniques in combination with higher power and higher frequencies aboard satellites allow for more efficient use of the space segment. This makes it possible to design small economical earth stations. The Advanced Communications Technology Satellite (ACTS) was chosen to test the system. ACTS, operating at the Ka band incorporates higher power, higher frequency, frequency and spatial reuse using spot beams and polarization.

Xiong, Fuqin; Wu, Dong; Jin, Min

1994-01-01

160

Applications of Wireless Communication Technologies for Intelligent Transport Systems  

Microsoft Academic Search

The DSRC (Dedicated Short Range Communication) system based on the wireless communication technologies is essential to provide ITS (Intelligent Transport Systems) services using the information and communication network which is named Smart Gateway. Focusing on the DSRC system, the RVC (Road-to-Vehicle Communication) system and IVC (Inter-Vehicle Communication) system are studied in this paper. The priority technical issues come out for

Kiyohito Tokuda

2001-01-01

161

Optical communication systems and applications in railway transportation systems  

Microsoft Academic Search

In this study, signalling in railway transportation systems are considered and their working mechanism is investigated. The applications and structures of the communications systems in railway transportation industry where high speed communications are essential for safety are assessed, within the framework of the broad band and high data transmission rates of optical fibers due to their operation in THz level.

N. Ozlem Unverdi; N. Aydin Unverdi

2012-01-01

162

System and Method of Animal Identification and Animal Transaction Authorization Using Iris Patterns.  

National Technical Information Service (NTIS)

A system and method of identification of an animal based on features of the iris of an eye are disclosed. An image of the animal's eye is captured using an iris acquisition device that combines a camera, an optical system, an illumination source, and a vi...

C. Musgrave J. L. Cambier

1999-01-01

163

Benefit-Cost Analysis of the National Animal Identification System.  

National Technical Information Service (NTIS)

The purpose of this study was to conduct a benefit-cost analysis of the United States National Animal Identification System (NAIS). The NAIS is a voluntary federal animal identification system operated by the Animal and Plant Health Inspection Service (AP...

2009-01-01

164

TANGO: A FRAMEWORK AND SYSTEM FOR ALGORITHM ANIMATION  

Microsoft Academic Search

Algorithm animation is the process of abstracting the data, operations, and semantics of computer programs, and then creating animated graphical views of those abstractions. Although a handful of algorithm animation systems have been developed in recent years, relatively little work has been done on the theoretical foundations of such systems. In this work we develop a conceptual framework with formal

John T. Stasko

1990-01-01

165

Linear Type Systems for Communication  

Microsoft Academic Search

Enhancing the type system of a programming language brings benets on many fronts. We dene and explore a simple concurrent functional language in a linear typing discipline, showing how more powerful types can lead to more controlled interaction between threads.

Tom Murphy VII

166

Integrated Formation Optical Communication and Estimation System  

NASA Technical Reports Server (NTRS)

An architecture has been designed that integrates formation estimation methodologies, precision formation sensing, and high-bandwidth formation communication into a robust, strap-on system that meets knowledge and communication requirements for the majority of planned, precision formation missions. Specifically, the integrated system supports (a) sub-millimeter metrology, (b) multiple greater than 10 Mbps communication channels over a large, 10 deg field-of-view (FOV), and (c) generalized formation estimation methodologies. The sensing sub-system consists of several absolute, metrology gauges with up to 0.1 mm precision that use amplitude-modulated lasers and a LISA-heritage phase meter. Since amplitude modulation is used, inexpensive and robust diode lasers may be used instead of complex, frequency-stabilized lasers such as for nanometer-level metrology. The metrology subsystem laser transceivers consist of a laser diode, collecting optics, and an avalanche photo diode (APD) for detecting incoming laser signals. The APD is necessary since received power is small due to the large (for optical applications) FOV. The phase meter determines the phase of the incoming amplitude modulations as measured by the APD. This phase is equivalent to time-of-flight and, therefore, distance. By placing three laser transceivers on each spacecraft, 18 clock-offset-corrupted distances are calculated. These measurements are communicated and averaged to obtain nine correct distances between the transceivers. From these correct distances, the range and bearing between spacecraft and their relative attitude are determined. Next, communication is integrated on the laser carrier through spectral separation. Metrology amplitude modulations are limited to the 45-50 MHz band, leaving 0-45 MHz for communication. Through careful design of coding scheme, error correction, and filters, six independent 10 Mbps receive channels are possible. Hence, a spacecraft can simultaneously broadcast at 10 Mbps and listen to six other spacecraft. The integrated sensing and communication architecture has been developed, as have formation estimation methodologies that allow the sensing topology to reconfigure as spacecraft maneuver. A bench-top implementation of the integrated sensing and communication architecture is in progress. The final, multiple sensing/communication systems will be tied together via formation estimation algorithms that are also undergoing further development.

Scharf, Daniel; Kuhnert, Andreas; Kovalik, Joseph; Hadaegh, Fred; Shaddock, Daniel

2008-01-01

167

Animation  

NSDL National Science Digital Library

Animation is making a splash with the recent box office hit, Shrek 2. This Topic in Depth explores how animation works, it's history and the entertaining as well as academic applications of animation. The first website provides a basic overview of digital cinema (1). More information on animation can be found on the second website (2). Digital Media FX provides this history (3 ) of animation. The Library of Congress has also put together a nice website (4 ) with some historical artifacts that for demonstrating a "a variety of elements that go into the creative process of developing and interpreting animated motion pictures." The fourth website provides an extensive list of online resources and academic uses for animation such as Chemistry, Evolution, Genetics, and Physics. (5 ). This fifth website posts the winners of the 2004 Character Animation Technologies competition (6 ). And finally, Slashdot has a nice expose on the Mathematics of Futurama (7).

168

Multimedia Communication System for the Blind  

Microsoft Academic Search

A Multimedia communication system for blind users is developed. The system is named MIMIZU and its terminal is composed of\\u000a a refreshable tactile graphic display and a stylus pen device that utilizes ultrasonic technologies. Blind users can make\\u000a drawings directly on the tactile display surface with the stylus pen. It was originally developed as a drawing system with\\u000a an erasing

Makoto Kobayashi; Tetsuya Watanabe

2006-01-01

169

Rewriting P Systems with Conditional Communication  

Microsoft Academic Search

A membrane system (P system) is a model of computation inspired by some basic features of the structure and behaviour of living\\u000a cells. In this paper we consider systems with string-objects processed by rewriting, with the communication controlled by\\u000a conditions on the contents of the strings. Symbols, substrings (in an arbitrary place, or as a prefix\\/suffix), or the shape\\u000a of

Paolo Bottoni; Anna Labella; Carlos Martín-vide; Gheorghe Paun

2002-01-01

170

A packet switched communications system for GRO  

NASA Technical Reports Server (NTRS)

This paper describes the packet switched Instrumenters Communication System (ICS) that was developed for the Command Management Facility at GSFC to support the Gamma Ray Observatory (GRO) spacecraft. The GRO ICS serves as a vital science data acquisition link to the GRO scientists to initiate commands for their spacecraft instruments. The system is ready to send and receive messages at any time, 24 hours a day and seven days a week. The system is based on X.25 and the International Standard Organization's (ISO) 7-layer Open Systems Interconnection (OSI) protocol model and has client and server components. The components of the GRO ICS are discussed along with how the Communications Subsystem for Interconnection (CSFI) and Network Control Program Packet Switching Interface (NPSI) software are used in the system.

Husain, Shabu; Yang, Wen-Hsing; Vadlamudi, Rani; Valenti, Joseph

1993-01-01

171

Propagation prediction models for wireless communication systems  

Microsoft Academic Search

A comprehensive review of the propagation prediction models for terrestrial wireless communication systems is presented in this paper. The classic empirical models are briefly described and the focus is placed on the application of ray-tracing techniques to the development of deterministic propagation models. Schemes to increase the computational efficiency and accuracy are discussed. Traditional statistical models are also briefly reviewed

Magdy F. Iskander; Zhengqing Yun

2002-01-01

172

Toward a System Model of Human Communication.  

National Technical Information Service (NTIS)

A model of a minimum set of subsystems contributing to the total system of human communication is hypothesized in which are identified four 'domains': a referent world, a formulator, an interpreter, and signs. The usefulness of the model relies on its app...

L. Schultz

1964-01-01

173

A Communication-Rich Systems Design Project.  

ERIC Educational Resources Information Center

Describes a Computer Information Systems course in which verbal communication processes are thoroughly integrated into the course without disturbing the technical content. Discusses the speaking, listening, writing, and reading activities associated with the course. Describes the challenges (for instructors as well as students) associated with the…

Darter, Marvin E.; Hoff, Katharine T.

1993-01-01

174

CAMAC based inter-compter communications system  

SciTech Connect

We have used CAMAC hardware to provide communications between dissimilar computers for the ELMO Bumpy Torus (EBT) experiment. The software supports file and individual message transfers. The system has proven to be both reliable and fast, with transmission rates of about 36,000 baud.

Greenwood, D.E.; Burris, R.D.; Young, K.G.

1981-10-01

175

Method and System for Pipeline Communication.  

National Technical Information Service (NTIS)

A pipeline communication system and method includes a pipeline having a surface extending along at least a portion of the length of the pipeline. A conductive bus is formed to and extends along a portion of the surface of the pipeline. The conductive bus ...

J. G. Richarson

2004-01-01

176

Mobility of a Disaster Recover Communication System  

Microsoft Academic Search

What is the best platform to build a Disaster Management Communication System (DMCS)? There is a need to investigate how to best use a DMCS. The two most important uses of a DMCS for any size disaster, is the need for information and getting relief to those that need it. The DMCS needs to collect information from the people affected

Edward Sobanski; Barbara Nicolai

2011-01-01

177

A Proof System for Communicating Sequential Processes  

Microsoft Academic Search

An axiomatic proof system is presented for proving partial correctness and absence of deadlock (and failure) of communicating sequential processes. The key (meta) rule introduces cooperation between proofs, a new concept needed to deal with proofs about synchronization by message passing. CSP's new convention for distributed termination of loops is dealt with. Applications of the method involve correctness proofs for

Krzysztof R. Apt; Nissim Francez; Willem P. de Roever

1980-01-01

178

Land-mobile satellite communication system  

NASA Technical Reports Server (NTRS)

A satellite communications system includes an orbiting communications satellite for relaying communications to and from a plurality of ground stations, and a network management center for making connections via the satellite between the ground stations in response to connection requests received via the satellite from the ground stations, the network management center being configured to provide both open-end service and closed-end service. The network management center of one embodiment is configured to provides both types of service according to a predefined channel access protocol that enables the ground stations to request the type of service desired. The channel access protocol may be configured to adaptively allocate channels to open-end service and closed-end service according to changes in the traffic pattern and include a free-access tree algorithm that coordinates collision resolution among the ground stations.

Yan, Tsun-Yee (Inventor); Rafferty, William (Inventor); Dessouky, Khaled I. (Inventor); Wang, Charles C. (Inventor); Cheng, Unjeng (Inventor)

1993-01-01

179

Energy efficiency in wireless communication systems  

DOEpatents

Wireless communication systems and methods utilize one or more remote terminals, one or more base terminals, and a communication channel between the remote terminal(s) and base terminal(s). The remote terminal applies a direct sequence spreading code to a data signal at a spreading factor to provide a direct sequence spread spectrum (DSSS) signal. The DSSS signal is transmitted over the communication channel to the base terminal which can be configured to despread the received DSSS signal by a spreading factor matching the spreading factor utilized to spread the data signal. The remote terminal and base terminal can dynamically vary the matching spreading factors to adjust the data rate based on an estimation of operating quality over time between the remote terminal and base terminal such that the amount of data being transmitted is substantially maximized while providing a specified quality of service.

Caffrey, Michael Paul; Palmer, Joseph McRae

2012-12-11

180

Parallel processing spacecraft communication system  

NASA Technical Reports Server (NTRS)

An uplink controlling assembly speeds data processing using a special parallel codeblock technique. A correct start sequence initiates processing of a frame. Two possible start sequences can be used; and the one which is used determines whether data polarity is inverted or non-inverted. Processing continues until uncorrectable errors are found. The frame ends by intentionally sending a block with an uncorrectable error. Each of the codeblocks in the frame has a channel ID. Each channel ID can be separately processed in parallel. This obviates the problem of waiting for error correction processing. If that channel number is zero, however, it indicates that the frame of data represents a critical command only. That data is handled in a special way, independent of the software. Otherwise, the processed data further handled using special double buffering techniques to avoid problems from overrun. When overrun does occur, the system takes action to lose only the oldest data.

Bolotin, Gary S. (Inventor); Donaldson, James A. (Inventor); Luong, Huy H. (Inventor); Wood, Steven H. (Inventor)

1998-01-01

181

Therapeutic Ultrasound to Non-Invasively Create Intra-Cardiac Communications in an Intact Animal Model  

PubMed Central

Objective To determine if pulsed cavitational ultrasound therapy (histotripsy) can accurately and safely generate ventricular septal defects (VSDs) through the intact chest of a neonatal animal, with the eventual goal of developing a non-invasive technique of creating intra-cardiac communications in patients with congenital heart disease. Background Histotripsy is an innovative ultrasonic technique that generates demarcated, mechanical tissue fractionation utilizing high intensity ultrasound pulses. Previous work has shown that histotripsy can create atrial septal defects in a beating heart in an open-chest canine model. Methods Nine neonatal pigs were treated with transcutaneous histotripsy targeting the ventricular septum. Ultrasound pulses of 5?s duration at a peak negative pressure of 13 MPa and a pulse repetition frequency of 1 kHz were generated by a 1 MHz focused transducer. The procedure was guided by real-time ultrasound imaging. Results VSDs were created in all pigs with diameters ranging from 2–6.5mm. Six pigs were euthanized within 2 hrs of treatment, while 3 were recovered and maintained for 2–3 days to evaluate lesion maturation and clinical side effects. There were only transient clinical effects and pathology revealed mild collateral damage around the VSD with no significant damage to other cardiac or extra-cardiac structures. Conclusions Histotripsy can accurately and safely generate VSDs through the intact chest in a neonatal animal model. These results suggest that with further advances, histotripsy can be a useful, non-invasive technique to create intra-cardiac communications, which currently require invasive catheter-based or surgical procedures, to clinically stabilize newborn infants with complex congenital heart disease.

Owens, Gabe E.; Miller, Ryan M.; Ensing, Greg; Ives, Kimberly; Gordon, David; Ludomirsky, Achi; Xu, Zhen

2010-01-01

182

Introduction to ELCOM. A Power Utility Oriented Data Communication System.  

National Technical Information Service (NTIS)

The power utility oriented data communication system ELCOM was developed to meet the need to communicate in a hierarchical process control system, which consists of both hardware (computers) and software from different manufacturers. The ISO Open Systems ...

R. Conrad N. Eggen T. Grytting J. Hegge H. Magnus

1988-01-01

183

46 CFR 169.713 - Engineroom communication system.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 false Engineroom communication system. 169.713 Section 169.713 Shipping COAST GUARD, DEPARTMENT OF HOMELAND...Vessel Control, Miscellaneous Systems, and Equipment § 169.713 Engineroom communication system. An...

2013-10-01

184

Outlining a Conception of Animal Welfare for Organic Farming Systems  

Microsoft Academic Search

The concept of animal welfare refersto the animal's quality of life. The choice ofdefinition always reflects some basicvaluation. This makes a particular conceptionof welfare value-dependent. Also, the animalhusbandry system reflects certain values oraims. The values reflected in the chosenconception of animal welfare ought tocorrespond to values aimed for in the husbandrysystem. The IFOAM Basic Standards and otherwritings dealing with organic

Vonne Lund; Helena Röcklinsberg

2001-01-01

185

Animation  

Microsoft Academic Search

\\u000a Ah, animation! Where would we be without the likes of Disney, Warner Bros., Walter Lanz, Hanna-Barbera, and dozens more like\\u000a them? For many people, animation is the reason to get involved with Flash as a creative outlet. This makes perfect sense, because Flash began life more than a decade ago\\u000a as an animation tool. Supplemental features like ActionScript, XML parsing,

Tom Green; David Stiller

186

Vocal corollary discharge communicates call duration to vertebrate auditory system.  

PubMed

Corollary discharge is essential to an animal's ability to filter self-generated from external stimuli. This includes acoustic communication, although direct demonstration of a corollary discharge that both conveys a vocal motor signal and informs the auditory system about the physical attributes of a self-generated vocalization has remained elusive for vertebrates. Here, we show the underlying synaptic activity of a neuronal vocal corollary discharge pathway in the hindbrain of a highly vocal species of fish. Neurons carrying the vocal corollary discharge are specifically adapted for the transmission of duration information, a predominant acoustic cue. The results reveal that vertebrates, like some insects, have a robust corollary discharge conveying call duration. Along with evidence for the influence of vocal duration on auditory encoding in mammals, these new findings suggest that linking vocal motor and corollary discharge pathways with pattern generating, call duration neurons is a shared network character across the animal kingdom. PMID:24285884

Chagnaud, Boris P; Bass, Andrew H

2013-11-27

187

Vocal Corollary Discharge Communicates Call Duration to Vertebrate Auditory System  

PubMed Central

Corollary discharge is essential to an animal's ability to filter self-generated from external stimuli. This includes acoustic communication, although direct demonstration of a corollary discharge that both conveys a vocal motor signal and informs the auditory system about the physical attributes of a self-generated vocalization has remained elusive for vertebrates. Here, we show the underlying synaptic activity of a neuronal vocal corollary discharge pathway in the hindbrain of a highly vocal species of fish. Neurons carrying the vocal corollary discharge are specifically adapted for the transmission of duration information, a predominant acoustic cue. The results reveal that vertebrates, like some insects, have a robust corollary discharge conveying call duration. Along with evidence for the influence of vocal duration on auditory encoding in mammals, these new findings suggest that linking vocal motor and corollary discharge pathways with pattern generating, call duration neurons is a shared network character across the animal kingdom.

2013-01-01

188

Acoustic system for communication in pipelines  

DOEpatents

A system for communication in a pipe, or pipeline, or network of pipes containing a fluid. The system includes an encoding and transmitting sub-system connected to the pipe, or pipeline, or network of pipes that transmits a signal in the frequency range of 3-100 kHz into the pipe, or pipeline, or network of pipes containing a fluid, and a receiver and processor sub-system connected to the pipe, or pipeline, or network of pipes containing a fluid that receives said signal and uses said signal for a desired application.

Martin, II, Louis Peter (San Ramon, CA); Cooper, John F. (Oakland, CA)

2008-09-09

189

Animator  

ERIC Educational Resources Information Center

Art and animation work is the most significant part of electronic game development, but is also found in television commercials, computer programs, the Internet, comic books, and in just about every visual media imaginable. It is the part of the project that makes an abstract design idea concrete and visible. Animators create the motion of life in…

Tech Directions, 2008

2008-01-01

190

Towards an interactive high visual complexity animation system  

Microsoft Academic Search

A computer animation system is discussed which employs interactive techniques and presents a unified approach to the graphical display of complex three dimensional data. The system facilitates the generation, manipulation and display of highly detailed data with the aid of interactive devices and a video interface to a standard color TV monitor. The system enables the animator to create a

C. Csuri; R. Hackathorn; R. Parent; W. Carlson; M. Howard

1979-01-01

191

Orbiter Interface Unit and Early Communication System  

NASA Technical Reports Server (NTRS)

This report describes the Orbiter Interface Unit (OIU) and the Early Communication System (ECOMM), which are systems of electronic hardware and software that serve as the primary communication links for the International Space Station (ISS). When a space shuttle is at or near the ISS during assembly and resupply missions, the OIU sends groundor crew-initiated commands from the space shuttle to the ISS and relays telemetry from the ISS to the space shuttle s payload data systems. The shuttle then forwards the telemetry to the ground. In the absence of a space shuttle, the ECOMM handles communications between the ISS and Johnson Space Center via the Tracking and Data Relay Satellite System (TDRSS). Innovative features described in the report include (1) a "smart data-buffering algorithm that helps to preserve synchronization (and thereby minimize loss) of telemetric data between the OIU and the space-shuttle payload data interleaver; (2) an ECOMM antenna-autotracking algorithm that selects whichever of two phased-array antennas gives the best TDRSS signal and electronically steers that antenna to track the TDRSS source; and (3) an ECOMM radiation-latchup controller, which detects an abrupt increase in current indicative of radiation-induced latchup and temporarily turns off power to clear the latchup, restoring power after the charge dissipates.

Cobbs, Ronald M.; Cooke, Michael P.; Cox, Gary L.; Ellenberger, Richard; Fink, Patrick W.; Haynes, Dena S.; Hyams, Buddy; Ling, Robert Y.; Neighbors, Helen M.; Phan, Chau T.; Prendergast, Kelly M.; Siekierski, James D.; Wade, Randall S.; Weisskopf, George A.; Yim, Hester J.; Adkins, Antha A.; Carl, James R..; Loh, Y. C.; Roberts, Charles; Steele, Douglas J.; DeSilva, Buveneka Kanishka; Killenb, Harold B.; Williams, Robert M.

2004-01-01

192

Integrated communications and optical navigation system  

NASA Astrophysics Data System (ADS)

The Integrated Communications and Optical Navigation System (ICONS) is a flexible navigation system for spacecraft that does not require global positioning system (GPS) measurements. The navigation solution is computed using an Unscented Kalman Filter (UKF) that can accept any combination of range, range-rate, planet chord width, landmark, and angle measurements using any celestial object. Both absolute and relative orbit determination is supported. The UKF employs a full nonlinear dynamical model of the orbit including gravity models and disturbance models. The ICONS package also includes attitude determination algorithms using the UKF algorithm with the Inertial Measurement Unit (IMU). The IMU is used as the dynamical base for the attitude determination algorithms. This makes the sensor a more capable plug-in replacement for a star tracker, thus reducing the integration and test cost of adding this sensor to a spacecraft. Recent additions include an integrated optical communications system which adds communications, and integrated range and range rate measurement and timing. The paper includes test results from trajectories based on the NASA New Horizons spacecraft.

Mueller, J.; Pajer, G.; Paluszek, M.

2013-12-01

193

NATO III satellite communications system control  

NASA Astrophysics Data System (ADS)

The System Control concepts to improve channel utilization and the recent progress of the design, development and integration of the Control Subsystem for the NATO III network are reported. The network operates with a large number of single destination TDM/QPSK/FDMA carriers to provide voice, low speed telegraph and medium speed data circuits. A power control algorithm to keep the link quality at the desired nominal level as well as improve satellite capacity and a traffic control algorithm allowing reconfiguration of the network to accommodate fluctuating traffic are presented. The System Control Software development cycle, consisting of top level design, which includes functional decomposition and software module structure, detailed design, integration and testing phases, is discussed. Various functional flow diagrams are provided illustrating the information interfaces to external communications, inter-component communications, the network database and the physical devices. An example illustrating the performance of power control and traffic control software is presented.

Sanli, N.; Lo, S. C.; Kota, S. L.; Aronson, M. H.

1984-04-01

194

The NATO III satellite communications system control  

NASA Astrophysics Data System (ADS)

The System Control concepts to improve channel utilization and the recent progress of the design, development and integration of the Control Subsystem for the NATO III network are reported. The network operates with a large number of single destination TDM/QPSK/FDMA carriers to provide voice, low speed telegraph and medium speed data circuits. A power control algorithm to keep the link quality at the desired nominal level as well as improve satellite capacity and a traffic control algorithm allowing reconfiguration of the network to accommodate fluctuating traffic are presented. The System Control Software development cycle, consisting of top level design, which includes functional decomposition and software module structure, detailed design, integration and testing phases, is discussed. Various functional flow diagrams are provided illustrating the information interfaces to external communications, inter-component communications, the network database and the physical devices. An example illustrating the performance of power control and traffic control software is presented.

Sanli, N.; Lo, S. C.; Kota, S. L.; Aronson, M. H.

195

Building intelligent communication systems for handicapped aphasiacs.  

PubMed

This paper presents an intelligent system allowing handicapped aphasiacs to perform basic communication tasks. It has the following three key features: (1) A 6-sensor data glove measures the finger gestures of a patient in terms of the bending degrees of his fingers. (2) A finger language recognition subsystem recognizes language components from the finger gestures. It employs multiple regression analysis to automatically extract proper finger features so that the recognition model can be fast and correctly constructed by a radial basis function neural network. (3) A coordinate-indexed virtual keyboard allows the users to directly access the letters on the keyboard at a practical speed. The system serves as a viable tool for natural and affordable communication for handicapped aphasiacs through continuous finger language input. PMID:22315546

Fu, Yu-Fen; Ho, Cheng-Seen

2010-01-01

196

VHF downline communication system for SLAR data  

NASA Technical Reports Server (NTRS)

A real time VHF downlink communication system is described for transmitting side-looking airborne radar (SLAR) data directly from an aircraft to a portable ground/shipboard receiving station. Use of this receiving station aboard the U.S. Coast Guard icebreaker Mackinaw for generating real-time photographic quality radar images is discussed. The system was developed and demonstrated in conjunction with the U.S Coast Guard and NOAA National Weather Service as part of the Project Icewarn all weather ice information system for the Great Lakes Winter Navigation Program.

Schertler, R. J.; Chase, T. L.; Mueller, R. A.; Kramarchuk, I.; Jirberg, R. J.; Gedney, R. T.

1979-01-01

197

Power variations of wireless communication systems.  

PubMed

The use of wireless digital communication devices like GSM, WCDMA, HSPA, DECT, and WiFi changes the exposure of electromagnetic waves toward the user. Concentrating on the power variations on a slow and fast time scale, these new systems are discussed. Experimental results for both uplink and downlink are included for a sample of systems. The spectrum of the power fluctuations is seen as a convenient and compact way of describing very complex system behavior. The results are of interest for scientific studies of epidemiology and biological effects, and for general electromagnetic compatibility (EMC) aspects. PMID:20112260

Andersen, J B; Mogensen, P E; Pedersen, G F

2010-05-01

198

Electronic circuits for communications systems: A compilation  

NASA Technical Reports Server (NTRS)

The compilation of electronic circuits for communications systems is divided into thirteen basic categories, each representing an area of circuit design and application. The compilation items are moderately complex and, as such, would appeal to the applications engineer. However, the rationale for the selection criteria was tailored so that the circuits would reflect fundamental design principles and applications, with an additional requirement for simplicity whenever possible.

1972-01-01

199

Emerging system for affectively charged interpersonal communication  

Microsoft Academic Search

The paper focuses on a novel system iFeel_IM! that integrates 3D virtual world Second Life, intelligent component for automatic emotion recognition from text messages, and innovative affective haptic interfaces providing additional nonverbal communication channels through simulation of emotional feedback and social touch (physical co-presence). The motivation behind our work is to enrich social interaction and emotional involvement of online interpersonal

Alena Neviarouskaya; Dzmitry Tsetserukou; Helmut Prendinger; Naoki Kawakami; Susumu Tachi; Mitsuru Ishizuka

2009-01-01

200

RESTRAINING SYSTEM FOR PLETHYSMOGRAPHY IN SMALL ANIMALS  

EPA Science Inventory

A restraining technique for immobilizing awake guinea pigs and rats during physiological measurements is described. The basic device consists of an adjustable acrylic holder that supports the animal in a standing position while restricting movement of the four legs. The holder al...

201

Secure communication using chaotic systems and Markovian jump systems  

Microsoft Academic Search

In this paper, a secure communication system using chaotic systems and Markovian jump systems (MJS) is proposed. MJS evolve by switching from one model to another according to a finite state Markov chain. In the proposed system the chaotic transmitter jumps from one chaotic map (model) to another while transmitting. This feature makes it difficult for someone to track the

T. Sathyan; T. Kirubarajan

2003-01-01

202

Satellite communications systems and technology. Volume 1: Analytical chapters  

Microsoft Academic Search

This is Volume 1 (Analytical Chapters) of the final report of the NASA\\/NSF Panel Satellite Communications Systems and Technology. The panel surveyed advanced technology being developed for commercial use in the satellite communications field in Europe, Japan, and Russia. All aspects of satellite communications were considered, including fixed, broadcast, mobile, personal communications, navigation, low earth orbit, and small satellites. The

Burton I. Edelson; Joseph N. Pelton; Charles W. Bostian; William T. Brandon; Vincent W. S. Chan; E. Paul Hager; Neil R. Helm; Raymond D. Jennings; Robert K. Kwan; Christoph E. Mahle

1993-01-01

203

Optical Data Communication for Earth Observation Satellite Systems.  

National Technical Information Service (NTIS)

The current development status of optical communication engineering in comparison to the conventional microwave systems and the different configurations of the optical data communication for Earth observation satellite systems are described. An outlook to...

J. Fischer E. Loecherbach

1991-01-01

204

Some Useful Coding Techniques for Binary Communication Systems.  

National Technical Information Service (NTIS)

An introduction to coding theory and a discussion of specific coding techniques are given as applied to digital communication systems. The place of coding in a communication system is illustrated and the various approaches to coding are discussed. The inf...

J. C. Hancock J. L. Holsinger

1964-01-01

205

Medium Frequency Wireless Communication System for Underground Mines.  

National Technical Information Service (NTIS)

A medium-frequency (MF) wireless communication system for underground mines, a new telecommunication system, works on low loss electromagnetic wave propagation modes that allow it to provide quality radio communications almost anywhere in a mine. The repo...

L. G. Stolarczyk

1984-01-01

206

Natural Disasters Prevention of Power Communications System  

Microsoft Academic Search

Natural disasters of China mainland mainly include earthquake disaster, geological disaster, sandstorm, typhoon, flood, thunderbolt, snowstorm, low-temperature sleet and freezing. For enhancing the emergency response capacity of power communication network, impact of the natural disasters on power communication facilities was analyzed. The disasters categories and distribution were introduced. China power communication network includes wire communication and wireless communication technology. For

Xin Miao; Xi Chen

2010-01-01

207

Computer Animation System Based on Rough Sets and Fuzzy Logic  

Microsoft Academic Search

\\u000a A fuzzy logic inference system was created, based on the analysis of animated motion features. The objective of the system\\u000a is to facilitate the creation of high quality animation by analyzing personalized styles contained in numerous animations.\\u000a Sequences portraying a virtual character acting with a differentiating personalized style (natural or exaggerated) and various\\u000a levels of fluidity were prepared and subjectively

Piotr Szczuko

2010-01-01

208

Emerging infectious diseases and animal social systems  

Microsoft Academic Search

Emerging infectious diseases threaten a wide diversity of animals, and important questions remain concerning disease emergence\\u000a in socially structured populations. We developed a spatially explicit simulation model to investigate whether—and under what\\u000a conditions—disease-related mortality can impact rates of pathogen spread in populations of polygynous groups. Specifically,\\u000a we investigated whether pathogen-mediated dispersal (PMD) can occur when females disperse after the resident

Charles L. Nunn; Peter H. Thrall; Kelly Stewart; Alexander H. Harcourt

2008-01-01

209

Delivery and Scavenging System for Small Animal Inhalational Anesthesia  

Microsoft Academic Search

Background. Inhalational agents have been widely used for anesthesia in laboratory animals. However, the safe use of inhalational agents in small laboratory animals has been limited by the lack of a suitable and effective scavenging system for the removal of waste anesthetic gases. The aim of the present study is to develop an anesthetic system that can be manufactured using

Wen Li; John Y. Tse; Anthony E. James; Lam Lik-Wang; Yip Chi-Kwan; Chan Man-Po; S. C. Sydney Chung

2001-01-01

210

A novel telemetry system for recording EEG in small animals  

Microsoft Academic Search

It has become increasingly evident that continuous EEG monitoring is necessary to observe the development of epilepsy in animals, and to determine the effect of drugs on spontaneous seizures. Telemetric recording systems have been increasingly used to monitor EEG in freely moving animals. One challenge faced by such systems is to monitor frequencies above 80Hz continuously for weeks. We present

Pishan Chang; Kevan S. Hashemi; Matthew C. Walker

2011-01-01

211

Social-Communicative Effects of the Picture Exchange Communication System (PECS) in Autism Spectrum Disorders  

ERIC Educational Resources Information Center

Background: The Picture Exchange Communication System (PECS) is a common treatment choice for non-verbal children with autism. However, little empirical evidence is available on the usefulness of PECS in treating social-communication impairments in autism. Aims: To test the effects of PECS on social-communicative skills in children with autism,…

Lerna, Anna; Esposito, Dalila; Conson, Massimiliano; Russo, Luigi; Massagli, Angelo

2012-01-01

212

Satellite communications systems and technology. Executive Summary  

NASA Technical Reports Server (NTRS)

NASA and the National Science Foundation (NSF) commissioned a panel of US experts to study the international status of satellite communications systems and technology. The study covers emerging systems concepts, applications, services, and the attendant technologies. The panel members travelled to Europe, Japan, and Russia to gather information first-hand. They visited 17 sites in Europe, 20 sites in Japan, and four in Russia. These included major manufacturers, government organizations, service providers, and associated R&D facilities. The panel's report was reviewed by the sites visited, by the panel, and by representatives of US industry. The report details the information collected and compares it to US activities.

Edelson, Burton I.; Pelton, Joseph N.; Bostian, Charles W.; Brandon, William T.; Chan, Vincent W. S.; Hager, E. Paul; Helm, Neil R.; Jennings, Raymond D.; Kwan, Robert; Mahle, Christoph E.

1993-01-01

213

Pilot-Tone System for Mobile Communications  

NASA Technical Reports Server (NTRS)

In mobile communication system called tone-calibrated technique, pilot tone provides phase- and amplitude-calibration reference to enable coherent demodulation of signal at receiver despite fading. Signal received by or from mobile terminal faded due to motion of terminal and propagation of signal along multiple paths. Fading introduces random amplitude modulation and phase modulation with bandwidth of twice Doppler frequency shift. Degrading effects of multipath fading reduced. Tonecalibrated technique for use with phase-modulated data or telephony systems using Manchester digital pulse-code modulation.

Davarian, F.

1986-01-01

214

Shuttle/TDRSS communications system performance analysis  

NASA Technical Reports Server (NTRS)

The results of the performance analysis performed on the Shuttle/Tracking and Data Relay Satellite System (TDRSS) communications system are presented. The existing Shuttle/TDRSS link simulation program were modified and refined to model the post-radio frequency interference TDRS hardware and to evaluate the performance degradation due to RFI effects. The refined link models were then used to determine, evaluate and assess expected S-band and Ku-band link performance. Parameterization results are presented for the ground station carrier and timing recovery circuits

Braun, W. R.

1980-01-01

215

Odyssey, an optimized personal communications satellite system  

NASA Astrophysics Data System (ADS)

Personal communications places severe demands on service providers and transmission facilities. Customers are not satisfied with the current levels of service and want improvements. Among the characteristics that users seek are: lower service rates, hand held convenience, acceptable time delays, ubiquitous service, high availability, reliability, and high quality. The space industry is developing commercial space systems for providing mobile communications to personal telephones. Provision of land mobile satellite service is fundamentally different from the fixed satellite service provided by geostationary satellites. In fixed service, the earth based antennas can depend on a clear path from user to satellite. Mobile users in a terrestrial environment commonly encounter blockage due to vegetation, terrain or buildings. Consequently, high elevation angles are of premium value. TRW studied the issues and concluded that a Medium Earth Orbit constellation is the best solution for Personal Communications Satellite Service. TRW has developed Odyssey, which uses twelve satellites in medium altitude orbit to provide personal communications satellite service. The Odyssey communications system projects a multibeam antenna pattern to the Earth. The attitude control system orients the satellites to ensure constant coverage of land mass and coastal areas. Pointing can be reprogrammed by ground control to ensure optimized coverage of the desired service areas. The payload architecture features non-processing, "bent pipe" transponders and matrix amplifiers to ensure dynamic power delivery to high demand areas. Circuit capacity is 3000 circuits per satellite. Each satellite weighs 1917 kg (4226 pounds) at launch and the solar arrays provide 3126 Watts of power. Satellites are launched in pairs on Ariane, Atlas, or other vehicles. Each satellite is placed in a circular orbit at an altitude of 10,354 km. There are three orbit planes inclined at 55° to the equatorial plane. Deployment of the satellites permits phased introduction of service. After only three launches, in which two satellites are launched into each plane, continuous service can be provided to most of the world. After three more launches for a total of 12 satellites, service can be expanded to all populated regions of the Earth with path diversity to most regions. The Odyssey system is superior to both geostationary satellites and low earth orbiting satellites. Odyssey provides many benefits to the end user which are described in the paper. These include: low cost, convenience, high availability, reliability, and acceptable time delay. Odyssey exhibits benefits for telecommunications operators: simple operations, incremental, phased startup, long space segment life-time, high profitability, dynamic flexibility for adjustment and short time to market. Since submission of an FCC application in 1991, TRW has continued to explore ways to further improve the Odyssey approach by expanding coverage to the entire world and reducing the initial investment while maintaining high quality service.

Rusch, Roger J.

216

Dynamic communication models in embedded system co-simulation  

Microsoft Academic Search

Many co-simulation techniques either suffer from poor performancewhen simulating communications intensive systems, or theyrepresent communications with a uniformly low level of detail.This paper presents a technique which allows communication tobe represented at multiple levels of detail and which gives a designerthe ability to dynamically choose the appropriate level fordifferent parts of the system. This paper also presents a tool whichuses

Ken Hines; Gaetano Borriello

1997-01-01

217

Emergency Communication for Electric Power System Based on Airship  

Microsoft Academic Search

The problems facing the communication for electric power system safety were recently highlighted by ice disaster in southern China and Wenchuan earthquake. The existing communication systems in the Yunnan power grid are far from adequate. Terrestrial networks are disabled by serious natural disaster. Satellite communication network is deficient in bandwidth, and has high propagation delay, which cannot satisfy the demand

Ming Huang; Jiang Yu; Jinsong Hu; Ling Zhao; Rong Zong

2009-01-01

218

Antenna technology for advanced mobile communication systems  

NASA Technical Reports Server (NTRS)

The onboard antenna front end is the key subsystem conditioning configuration and performance of mobile communication satellites. The objectives of this paper are to demonstrate this key role and to review L-band satellite antenna technology for earth coverage and regional applications. Multibeam arrays are first discussed, then unfurlable and inflatable reflector antennas are described. These technologies are now qualified in Europe for future mobile systems, for which the optimum choice of antenna technology has been found to be the key to efficient use of spectrum and power resources.

Rammos, Emmanuel; Roederer, Antoine; Rogard, Roger

1988-01-01

219

A Simple Fiber-Optic Communications System  

NSDL National Science Digital Library

In this video adapted from the ICT Center, students will "learn how rise-time analysis is performed to determine the maximum data range of a fiber optic communications system." The video also demonstrates how a transmitter, fiber, and receiver work together. The material is intended for students in grades 11-12. Running time for the video is 5:31.The lesson is accompanied by discussion questions, teaching tips and state educational standards. Users who sign up for a free account can save the resource and download the video as well.

2012-10-16

220

Antenna technology for advanced mobile communication systems  

NASA Astrophysics Data System (ADS)

The onboard antenna front end is the key subsystem conditioning configuration and performance of mobile communication satellites. The objectives of this paper are to demonstrate this key role and to review L-band satellite antenna technology for earth coverage and regional applications. Multibeam arrays are first discussed, then unfurlable and inflatable reflector antennas are described. These technologies are now qualified in Europe for future mobile systems, for which the optimum choice of antenna technology has been found to be the key to efficient use of spectrum and power resources.

Rammos, Emmanuel; Roederer, Antoine; Rogard, Roger

1988-05-01

221

Adaptive communication in animals and robots 1 This project was supported in part by a contract from the Office of Naval Research. 1  

Microsoft Academic Search

We present a real-time description of animal communication and cooperation in terms of the interaction between two identical models of operant behavior. Each model has been shown capable of describing many features of avoidance behavior in animals. In order to describe adaptive communication, it is assumed that the same mechanisms that control the generation of responses control the generation of

N. A Schmajuk; W. A Szymanski; E Axelrad Weaver

1999-01-01

222

GAS MAIN SENSOR AND COMMUNICATIONS NETWORK SYSTEM  

SciTech Connect

Automatika, Inc. was contracted by the Department of Energy (DOE) and with co-funding from the New York Gas Group (NYGAS), to develop an in-pipe natural gas prototype measurement and wireless communications system for assessing and monitoring distribution networks. A prototype system was built for low-pressure cast-iron mains and tested in a spider- and serial-network configuration in a live network in Long Island with the support of Keyspan Energy, Inc. The prototype unit combined sensors capable of monitoring pressure, flow, humidity, temperature and vibration, which were sampled and combined in data-packages in an in-pipe master-slave architecture to collect data from a distributed spider-arrangement, and in a master-repeater-slave configuration in serial or ladder-network arrangements. It was found that the system was capable of performing all data-sampling and collection as expected, yielding interesting results as to flow-dynamics and vibration-detection. Wireless in-pipe communications were shown to be feasible and valuable data was collected in order to determine how to improve on range and data-quality in the future.

Hagen Schempf, Ph.D.

2003-02-27

223

Animating operating systems algorithms with XTANGO  

Microsoft Academic Search

In operating systems courses, students study the major algorithmsused in operating systems to manage the variousobjects and resources in a computing system: processes,files, buffer space, processors, messages, main memory,semaphores, and disk storage. Various classical synchronizationproblems such as the dining philosophers, thereaders and writers, and the producers and consumers withbounded buffer are also analyzed. Even though the computingsystems being studied are

Stephen J. Hartley

1994-01-01

224

Computer animated digital arc diagnostic system  

Microsoft Academic Search

An arc diagnostic system has been developed for analyzing arc motion, structure, and intensity in electrical components such as molded case circuit breakers and contactors. The system utilizes an array of fiber-optic cables and matching photodiode receivers to monitor the light from an arc and convert the light into electrical signals, which are acquired by a high-speed transient digitizing system.

John J. Shea; David Boles; Yun-Ko Chien; Rod Zeigler

1994-01-01

225

Static and Animated Presentations in Learning Dynamic Mechanical Systems  

ERIC Educational Resources Information Center

In two experiments, we investigated how learners comprehend the functioning of a three-pulley system from a presentation on a computer screen. In the first experiment (N = 62) we tested the effect of static vs. animated presentations on comprehension. In the second experiment (N = 45), we tested the effect of user-control of an animated

Boucheix, Jean-Michel; Schneider, Emmanuel

2009-01-01

226

Effects of gravity perturbation on developing animal systems  

NASA Technical Reports Server (NTRS)

The use of developing animal systems to analyze the effects of microgravity on animals is discussed. Some of the key features of developing systems, especially embryos, are reviewed and relevant space data are summarized. Issues to be addressed in the design of future space experiments are discussed. It is noted that an embryo which exhibits ground based gravity effects should be selected for use as a model system and individual variation in gravity response among batches of embryos should be taken into account.

Malacinski, G. M.; Neff, A. W.

1986-01-01

227

An advanced domestic satellite communications system  

NASA Technical Reports Server (NTRS)

An updated traffic projection for U.S. domestic satellite communications service covering a period of 15 years; mid-1980 to mid-1995 was prepared. This model takes into account expected technology advances and reductions in transmission costs, legislative and regulatory changes permitting increased competition, and rising energy costs which will encourage more extensive substitution of telecommunications for travel. The historical development and current status of satellite systems are discussed as well as the characteristics of follow-on systems. Orbital arc utilization, spacecraft configuration for single shuttle launch, Earth station configuration, and system costs are examined. Areas which require technology development include multiple beam frequency reuse antennas, on-board switching, intersatellite links, and ka-band operation. Packing and deployment schemes for enclosing the satellite within the shuttle orbiter bay must also be devised.

1980-01-01

228

Random digital encryption secure communication system  

NASA Technical Reports Server (NTRS)

The design of a secure communication system is described. A product code, formed from two pseudorandom sequences of digital bits, is used to encipher or scramble data prior to transmission. The two pseudorandom sequences are periodically changed at intervals before they have had time to repeat. One of the two sequences is transmitted continuously with the scrambled data for synchronization. In the receiver portion of the system, the incoming signal is compared with one of two locally generated pseudorandom sequences until correspondence between the sequences is obtained. At this time, the two locally generated sequences are formed into a product code which deciphers the data from the incoming signal. Provision is made to ensure synchronization of the transmitting and receiving portions of the system.

Doland, G. D. (inventor)

1982-01-01

229

Systems for animal exposure in full-scale fire tests  

NASA Technical Reports Server (NTRS)

Two systems for exposing animals in full-scale fire tests are described. Both systems involve the simultaneous exposure of two animal species, mice and rats, in modular units; determination of mortality, morbidity, and behavioral response; and analysis of the blood for carboxyhemoglobin. The systems described represent two of many possible options for obtaining bioassay data from full-scale fire tests. In situations where the temperatures to which the test animals are exposed can not be controlled, analytical techniques may be more appropriate than bioassay techniques.

Hilado, C. J.; Cumming, H. J.; Kourtides, D. A.; Parker, J. A.

1977-01-01

230

GAS MAIN SENSOR AND COMMUNICATIONS NETWORK SYSTEM  

SciTech Connect

Automatika, Inc. was contracted by the Department of Energy (DOE) and with co-funding from the New York Gas Group (NYGAS), to develop an in-pipe natural gas prototype measurement and wireless communications system for assessing and monitoring distribution networks. In Phase II of this three-phase program, an improved prototype system was built for low-pressure cast-iron and high-pressure steel (including a no-blow installation system) mains and tested in a serial-network configuration in a live network in Long Island with the support of Keyspan Energy, Inc. The experiment was carried out in several open-hole excavations over a multi-day period. The prototype units (3 total) combined sensors capable of monitoring pressure, flow, humidity, temperature and vibration, which were sampled and combined in data-packages in an in-pipe master-repeater-slave configuration in serial or ladder-network arrangements. It was verified that the system was capable of performing all data-sampling, data-storage and collection as expected, yielding interesting results as to flow-dynamics and vibration-detection. Wireless in-pipe communications were shown to be feasible and the system was demonstrated to run off in-ground battery- and above-ground solar power. The remote datalogger access and storage-card features were demonstrated and used to log and post-process system data. Real-time data-display on an updated Phase-I GUI was used for in-field demonstration and troubleshooting.

Hagen Schempf

2004-09-30

231

Diablo Canyon plant information management system and integrated communication system  

SciTech Connect

The implementation of a comprehensive maintenance system called the plant information management system (PIMS) at the Diablo Canyon plant, together with its associated integrated communication system (ICS), is widely regarded as the most comprehensive undertaking of its kind in the nuclear industry. This paper provides an overview of the program at Diablo Canyon, an evaluation of system benefits, and highlights the future course of PIMS.

Stanley, J.W.; Groff, C.

1990-06-01

232

Geographically distributed multiprocessor time-shared communication processing system  

SciTech Connect

This patent describes a multiprocessor communication processing system for use in a communication or telephone network wherein in the system each processor supports processes, a communication system having communication connections between processes for transferring data in accordance with communication parameters, and means invoked by each process requesting a connection to the other processes in the same and different processors for selecting a connection therebetween and passing data defining communication parameters to the selected connection, at least a portion of the communication parameter data being defined by the means invoked by the requesting process independent of the requesting process program code and at least a portion of the communication parameter data being supplied to the means invoked by the requesting process by means responsive to program code being executed by the requesting process.

Babecki, G.R.; Kaplan, F.; Liu, H.R.; MacLachlan, G.F.; McDonald, J.F.; Palframan, J.D.; Welt, M.J.; Wendt, T.A.; Yates, G.S.

1986-09-30

233

Ultrasonic speech translator and communications system  

DOEpatents

A wireless communication system undetectable by radio frequency methods for converting audio signals, including human voice, to electronic signals in the ultrasonic frequency range, transmitting the ultrasonic signal by way of acoustical pressure waves across a carrier medium, including gases, liquids, or solids, and reconverting the ultrasonic acoustical pressure waves back to the original audio signal. The ultrasonic speech translator and communication system includes an ultrasonic transmitting device and an ultrasonic receiving device. The ultrasonic transmitting device accepts as input an audio signal such as human voice input from a microphone or tape deck. The ultrasonic transmitting device frequency modulates an ultrasonic carrier signal with the audio signal producing a frequency modulated ultrasonic carrier signal, which is transmitted via acoustical pressure waves across a carrier medium such as gases, liquids or solids. The ultrasonic receiving device converts the frequency modulated ultrasonic acoustical pressure waves to a frequency modulated electronic signal, demodulates the audio signal from the ultrasonic carrier signal, and conditions the demodulated audio signal to reproduce the original audio signal at its output. 7 figs.

Akerman, M.A.; Ayers, C.W.; Haynes, H.D.

1996-07-23

234

Integrated source and channel encoded digital communication system design study  

NASA Technical Reports Server (NTRS)

This study investigated the configuration and integration of a wideband communication system with a Ku-band rendezvous radar system. The goal of the study was to provide as much commonality between the two systems as possible. The antenna design was described with the only change being the requirement for dual polarization (linear for the radar system and circular for the communication system).

Huth, G. K.; Udalov, S.

1974-01-01

235

India's domestic satellite communication system - INSAT  

NASA Astrophysics Data System (ADS)

The Indian National Satellite System (INSAT-I) possesses two multipurpose satellites in geostationary orbit, each of which has twelve 36 MHz-wide C-band channels, two 36 MHz-wide S-band channels, a Very High Resolution Radiometer for earth observation in the visible and IR bands, and a 200 kHz-wide Data Relay Transponder. The ground segment of INSAT-I consists of five large earth stations, 13 medium earth stations, 10 remote area terminals, and one mobile emergency communications terminal. C-band channels are to be used for thick and thin route telephony, while S-band channels are devoted to TV broadcasts to community receivers, radio networking, and Disaster Warning System services, using low level injected carriers. Data Collection Platforms relay meteorological and hydrological data via the Data Relay Transponder to a central station.

Kibe, S. V.; Thomas, G.

236

SAW based systems for mobile communications satellites  

NASA Technical Reports Server (NTRS)

Modern mobile communications satellites, such as INMARSAT 3, EMS, and ARTEMIS, use advanced onboard processing to make efficient use of the available L-band spectrum. In all of these cases, high performance surface acoustic wave (SAW) devices are used. SAW filters can provide high selectivity (100-200 kHz transition widths), combined with flat amplitude and linear phase characteristics; their simple construction and radiation hardness also makes them especially suitable for space applications. An overview of the architectures used in the above systems, describing the technologies employed, and the use of bandwidth switchable SAW filtering (BSSF) is given. The tradeoffs to be considered when specifying a SAW based system are analyzed, using both theoretical and experimental data. Empirical rules for estimating SAW filter performance are given. Achievable performance is illustrated using data from the INMARSAT 3 engineering model (EM) processors.

Peach, R. C.; Miller, N.; Lee, M.

1993-01-01

237

Adaptive noise reduction in aircraft communication systems  

NASA Astrophysics Data System (ADS)

In many military environments, such as fighter jet cockpits, the increasing use of digital communication systems has created a need for robust vocoders and speech recognition systems. However, the high level of ambient noise in such environments makes vocoders less intelligible and makes reliable speech recognition more difficult. One method of enhancing the noise-corrupted speech is adaptive noise cancellation. In previous research, this method was tested in a simulated cockpit environment, yielding impressive results. However, in new simulations, reflecting more realistic conditions, adaptive noise cancellation has been less successful. Spectral analysis of the data shows that the spectral concentration of the ambient noise, along with the microphone characteristics, has a significant effect on the performance of adaptive noise cancellation.

Rodriguez, Jeffrey J.

1987-01-01

238

Odyssey, an optimized personal communications satellite system  

NASA Astrophysics Data System (ADS)

Personal communications places severe demands on service providers and transmission facilities. Customers are not satisfied with the current levels of service and want improvements. Among the characteristics that users seek are: lower service rates, hand held convenience, acceptable time delays, ubiquitous service, high availability, reliability, and high quality. The space industry in developing commercial space systems for providing mobile communications to personal telephones. Provision of land mobile satellite service is fundamentally different from the fixed satellite service provided by geostationary satellites. In fixed service, the earth based antennas can depend on a clear path from user to satellite. Mobile users in a terrestrial environment commonly encounter blockage due to vegetation, terrain or buildings. Consequently, high elevation angles are of premium value. TRW studied the issues and concluded that a Medium Earth Orbit constellation is the best solution for Personal Communications Satellite Service. TRW has developed Odyssey, which uses twelve satellites in medium altitude orbit to provide personal communications satellite service. The Odyssey communications system projects a multibeam antenna pattern to the Earth. The attitude control system orients the satellites to ensure constant coverage of land mass and coastal areas. Pointing can be reprogrammed by ground control to ensure optimized coverage of the desired service areas. The payload architecture features non-processing, 'bent pipe' transponders and matrix amplifiers to ensure dynamic power delivery to high demand areas. Circuit capacity is 3000 circuits per satellite. Each satellite weighs 1917 kg (4226 pounds) at launch and the solar arrays provide 3126 watts of power. Satellites are launched in pairs on Ariane, Atlas, or other vehicles. Each satellite is placed in a circular orbit at an altitude of 10,354 km. system is superior to both geostationary satellites and low earth orbiting satellites. -Odyssey provides many benefits to the end user which are described in the paper. These include: low cost, convenience, high availability, reliability, and acceptable time delay. Odyssey exhibits benefits for telecommunications operators: simple operations, incremental, phased startup, long space segment life-time, high profitability, dynamic flexibility for adjustment and short time to market. %Since submission of an FCC application in 1991, TRW has continued to explore ways to further improve the Odyssey approach by expanding coverage to the entire world and reducing the initial investment while maintaining high quality service.

Rusch, Roger J.

239

Design Parameters for Animal Waste Treatment Systems.  

National Technical Information Service (NTIS)

Laboratory, pilot plant, and full-scale studies evaluated design parameters for liquid aeration systems treating livestock waste. Of the various approaches tested, the mass balance approach is the preferred approach since it yielded results comparable to ...

T. B. S. Prakasam R. C. Loehr P. Y. Yang T. W. Scott T. W. Bateman

1974-01-01

240

Survey of Satellite Communications System Vulnerabilities.  

National Technical Information Service (NTIS)

The U.S. military's increasing reliance on commercial and military communications satellites to enable widely-dispersed, mobile forces to communicate makes these space assets increasingly vulnerable to attack by adversaries. Attacks on these satellites co...

J. A. Steinberger

2008-01-01

241

Tone-activated, remote, alert communication system  

NASA Technical Reports Server (NTRS)

Pocket sized transmitter, frequency modulated by crystal derived tones, with integral loop antenna provides police with easy operating alert signal communicator which uses patrol car radio to relay signal. Communication channels are time shared by several patrol units.

Baker, C. D.; Couvillon, L. A.; Hubbard, W. P.; Kollar, F. J.; Postal, R. B.; Tegnelia, C. R.

1971-01-01

242

Compact CT\\/SPECT small-animal imaging system  

Microsoft Academic Search

We have developed a dual-modality CT\\/SPECT imaging system for small-animal imaging applications. The X-ray system comprises a commercially available micro-focus X-ray tube and a CCD-based X-ray camera. X-ray transmission measurements are performed based on cone-beam geometry. Individual projections are acquired by rotating the animal about a vertical axis in front of the CCD detector. A high-resolution CT image is obtained

George A. Kastis; Lars R. Furenlid; Donald W. Wilson; Todd E. Peterson; H. Bradford Barber; Harrison H. Barrett

2004-01-01

243

A Fast Individual Face Modeling and Facial Animation System  

Microsoft Academic Search

\\u000a In this paper, we present a fast individual face modeling and animation system. The input of the system is a single frontal\\u000a face image, which is captured by an ordinary video camera. And the output is 3D individual facial animation. Firstly, an Adaboost\\u000a method is used to detect the face in the image. Then the key points of the face

Bin Ding; Yangsheng Wang; Jian Yao; Peng Lu

2006-01-01

244

Communication in reactive multiagent robotic systems  

Microsoft Academic Search

Multiple cooperating robots are able to complete many tasks more quickly and reliably than one robot alone. Communication between the robots can multiply their capabilities and effectiveness, but to what extent? In this research, the importance of communication in robotic societies is investigated through experiments on both simulated and real robots. Performance was measured for three different types of communication

Tucker R. Balch; Ronald C. Arkin

1994-01-01

245

Communications technology guidelines for EMS\\/SCADA systems  

Microsoft Academic Search

The purpose of this Guideline Technical Paper is to provide a summary of the different communications technologies available for use or application with EMS\\/SCADA system projects. All of the various communication media are addressed with a brief description along with tables of the advantages and disadvantages of each and recommendations for choosing the most appropriate communication technology. The technologies discussed

Donald J. Marihart

2001-01-01

246

Application of the Iridium Satellite System to Aeronautical Communications  

NASA Technical Reports Server (NTRS)

The next generation air transportation system will require greater air-ground communications capacity to accommodate more air traffic with increased safety and efficiency. Communications will remain primarily terrestrially based, but satellite communications will have an increased role. Inmarsat s aeronautical services have been approved and are in use for aeronautical safety communications provided by geostationary satellites. More recently the approval process for the Iridium low earth orbit constellation is nearing completion. The current Iridium system will be able to provide basic air traffic services communications suitable for oceanic, remote and polar regions. The planned second generation of the Iridium system, called Iridium NEXT, will provide enhanced capabilities and enable a greater role in the future of aeronautical communications. This paper will review the potential role of satellite communications in the future of air transportation, the Iridium approval process and relevant system testing, and the potential role of Iridium NEXT.

Kerczewski, Robert J.; Meza, Mike; Gupta, Om

2008-01-01

247

A Micro Satellite Communication System Architecture  

NASA Astrophysics Data System (ADS)

In 2000 the European Space Agency's (ESA) Office for Educational Project Outreach Activities has started the Student Space Exploration &Technology Initiative (SSETI). The main objective of this project is to construct and to launch a microsatellite developed by a network of European students. The microsatellite will be mainly used to transmit pictures of the space to earth, to perform plasma experiments and to test all the subsystems for further missions. The data transfer from on-board the satellite to the ground station will be ensued through an innovative communication system composed of two different channels alternatively used to built a connection with the earth. A low data rate channel has to be activated to download telemetry and upload telecommand during the stabilisation mode or when the satellite is not visible from the earth. During the microsatellite nominal operation mode, pictures and data of scientific interest have to be sent from space to the ground station through an additional high data rate channel. As the satellite operation mode changes, a switching system optimizes the onboard power budget selecting the most convenient option between a directive and an omnidirectional antenna, designed to implement the high and low data rate channels respectively. The low gain channel uses two circular polarised patches while a 2x2 microstrip array has been chosen for realising the high rate communication link. Both the antennas are low profile radiators and they have been designed to be conformally mounted onto the microsatellite surface. Prototypes of the two antennas have been realised and tested. A description of the antenna's design process will be given together with a review of the entire system architecture rationale.

Fragale, Francesco; Boccia, Luigi

2002-01-01

248

Space-to-Space Communications System  

NASA Technical Reports Server (NTRS)

The Space-to-Space Communications System (SSCS) is an Ultra High Frequency (UHF) Time-Division-Multiple Access (TDMA) system that is designed, developed, and deployed by the NASA Johnson Space Center (JSC) to provide voice, commands, telemetry and data services in close proximity among three space elements: International Space Station (ISS), Space Shuttle Orbiter, and Extravehicular Mobility Units (EMU). The SSCS consists of a family of three radios which are, Space-to-Space Station Radio (SSSR), Space-to-Space Orbiter Radio (SSOR), and Space-to-Space Extravehicular Mobility Radio (SSER). The SSCS can support up to five such radios at a time. Each user has its own time slot within which to transmit voice and data. Continuous Phase Frequency Shift Keying (CPFSK) carrier modulation with a burst data rate of 695 kbps and a frequency deviation of 486.5 kHz is employed by the system. Reed-Solomon (R-S) coding is also adopted to ensure data quality. In this paper, the SSCS system requirements, operational scenario, detailed system architecture and parameters, link acquisition strategy, and link performance analysis will be presented and discussed

Tu, Kwei; Gaylor, Kent; Vitalpur, Sharada; Sham, Cathy

1999-01-01

249

Radiation-hardened microwave communications system  

SciTech Connect

To develop a wireless communication system to meet the stringent requirements for a nuclear hot cell and similar environments, including control of advanced servomanipulators, a microwave signal transmission system development program was established to produce a demonstration prototype for the Consolidated Fuel Reprocessing Program at Oak Ridge National Laboratory (ORNL). Proof-of-principle tests in a partially metal lined enclosure at ORNL successfully demonstrated the feasibility of directed microwave signal transmission techniques for remote systems applications. The potential for much more severe radio-frequency (RF) multipath propagation conditions in fully metal lined cells led to a programmatic decision to conduct additional testing in more typical hot-cell environments at other sites. Again, the test results were excellent. Based on the designs of the earlier systems, an advanced microwave signal transmission system configuration was subsequently developed that, in highly reflective environments, will support both high-performance video channels and high baud-rate digital data links at total gamma dose tolerance levels exceeding 10[sup 7] rads and at elevated ambient temperatures.

Smith, S.F.; Bible, D.W.; Crutcher, R.I.; Hannah, J.H.; Moore, J.A.; Nowlin, C.H.; Vandermolen, R.I. (Oak Ridge National Lab., TN (United States)); Chagnot, D.; LeRoy, A. (CEA Centre d'Etudes Nucleaires de Grenoble, 38 (France))

1993-01-01

250

Radiation-hardened microwave communications system  

SciTech Connect

To develop a wireless communication system to meet the stringent requirements for a nuclear hot cell and similar environments, including control of advanced servomanipulators, a microwave signal transmission system development program was established to produce a demonstration prototype for the Consolidated Fuel Reprocessing Program at Oak Ridge National Laboratory (ORNL). Proof-of-principle tests in a partially metal lined enclosure at ORNL successfully demonstrated the feasibility of directed microwave signal transmission techniques for remote systems applications. The potential for much more severe radio-frequency (RF) multipath propagation conditions in fully metal lined cells led to a programmatic decision to conduct additional testing in more typical hot-cell environments at other sites. Again, the test results were excellent. Based on the designs of the earlier systems, an advanced microwave signal transmission system configuration was subsequently developed that, in highly reflective environments, will support both high-performance video channels and high baud-rate digital data links at total gamma dose tolerance levels exceeding 10{sup 7} rads and at elevated ambient temperatures.

Smith, S.F.; Bible, D.W.; Crutcher, R.I.; Hannah, J.H.; Moore, J.A.; Nowlin, C.H.; Vandermolen, R.I. [Oak Ridge National Lab., TN (United States); Chagnot, D.; LeRoy, A. [CEA Centre d`Etudes Nucleaires de Grenoble, 38 (France)

1993-03-01

251

Radiation-hardened microwave communications system  

NASA Astrophysics Data System (ADS)

To develop a wireless communication system to meet the stringent requirements for a nuclear hot cell and similar environments, including control of advanced servomanipulators, a microwave signal transmission system development program was established to produce a demonstration prototype for the Consolidated Fuel Reprocessing Program at Oak Ridge National Laboratory (ORNL). Proof-of-principle tests in a partially metal lined enclosure at ORNL successfully demonstrated the feasibility of directed microwave signal transmission techniques for remote systems applications. The potential for much more severe radio-frequency (RF) multipath propagation conditions in fully metal lined cells led to a programmatic decision to conduct additional testing in more typical hot-cell environments at other sites. Again, the test results were excellent. Based on the designs of the earlier systems, an advanced microwave signal transmission system configuration was subsequently developed that, in highly reflective environments, will support both high-performance video channels and high baud-rate digital data links at total gamma dose tolerance levels exceeding 10(exp 7) rads and at elevated ambient temperatures.

Smith, S. F.; Bible, D. W.; Crutcher, R. I.; Hannah, J. H.; Moore, J. A.; Nowlin, C. H.; Vandermolen, R. I.; Chagnot, D.; Leroy, A.

1993-03-01

252

Digital Autonomous Terminal Access Communication (DATAC) system  

NASA Technical Reports Server (NTRS)

In order to accommodate the increasing number of computerized subsystems aboard today's more fuel efficient aircraft, the Boeing Co. has developed the DATAC (Digital Autonomous Terminal Access Control) bus to minimize the need for point-to-point wiring to interconnect these various systems, thereby reducing total aircraft weight and maintaining an economical flight configuration. The DATAC bus is essentially a local area network providing interconnections for any of the flight management and control systems aboard the aircraft. The task of developing a Bus Monitor Unit was broken down into four subtasks: (1) providing a hardware interface between the DATAC bus and the Z8000-based microcomputer system to be used as the bus monitor; (2) establishing a communication link between the Z8000 system and a CP/M-based computer system; (3) generation of data reduction and display software to output data to the console device; and (4) development of a DATAC Terminal Simulator to facilitate testing of the hardware and software which transfer data between the DATAC's bus and the operator's console in a near real time environment. These tasks are briefly discussed.

Novacki, Stanley M., III

1987-01-01

253

Using Sequence Diagrams to Detect Communication Problems Between Systems  

NASA Technical Reports Server (NTRS)

Many software systems are evolving complex system of systems (SoS) for which inter-system communication is both mission-critical and error-prone. Such communication problems ideally would be detected before deployment. In a NASA-supported Software Assurance Research Program (SARP) project, we are researching a new approach addressing such problems. In this paper, we show that problems in the communication between two systems can be detected by using sequence diagrams to model the planned communication and by comparing the planned sequence to the actual sequence. We identify different kinds of problems that can be addressed by modeling the planned sequence using different level of abstractions.

Lindvall, Mikael; Ackermann, Chris; Stratton, William C.; Sibol, Deane E.; Ray, Arnab; Yonkwa, Lyly; Kresser, Jan; Godfrey, Sally H.; Knodel, Jens

2008-01-01

254

Worldwide Seamless Cellular Satellite Communications: The Global Mobile Communication by Globalstar System.  

National Technical Information Service (NTIS)

Presentation viewgraphs are presented that describe the need and technology requirements for a worldwide cellular satellite communication system. Specific services provided by such a system are outlined and the role of the service provider is described.

A. J. Navarra

1992-01-01

255

Method and system for pipeline communication  

DOEpatents

A pipeline communication system and method includes a pipeline having a surface extending along at least a portion of the length of the pipeline. A conductive bus is formed to and extends along a portion of the surface of the pipeline. The conductive bus includes a first conductive trace and a second conductive trace with the first and second conductive traces being adapted to conformally couple with a pipeline at the surface extending along at least a portion of the length of the pipeline. A transmitter for sending information along the conductive bus on the pipeline is coupled thereto and a receiver for receiving the information from the conductive bus on the pipeline is also couple to the conductive bus.

Richardson; John G. (Idaho Falls, ID) [Idaho Falls, ID

2008-01-29

256

An Object Oriented Design of a Graphics Animation System  

Microsoft Academic Search

The software literature has many papers expounding the benefits of object oriented systems for developing complex software systems. Some feel that object oriented programming will be in the 80's what structured pro- gramming was in the 70's. This paper investigates the application of the object oriented philosophy to the design of a 3D computer graphics animation system currently under development

William Lorensen

257

COMPUTER VIRUS EDUCATIONAL SYSTEM USING ANIMATED PEDAGOGICAL AGENT TECHNOLOGY  

Microsoft Academic Search

This paper describes a framework for practical application of interface agent technology as means of solving some persistent problems in educational environments. The system has been developed is called a Computer Virus Educational System Using Animated Pedagogical Agent or CAPA. CAPA will cover range of subjects from learning the basics computer virus to handling and management of computer system in

Zasriati Azla Sabot; Abdul Razak; Iznora Aini Zolkifly; Tan Teik Lew

258

A passive integrated transponder system for tracking animal movements  

USGS Publications Warehouse

We describe an automated system that uses passive integrated transponder (PIT) tags to track movements of animals past specific locations. The system was designed to operate maintenance free for several months, be secure from vandalism and environmental damage, and record the identity, date, and time of passage of animals past a 2.4-m wide area. We used the system to monitor effectively the movements of 172 desert tortoises (Gopherus agassizii) through 2 storm drain culverts that pass beneath a state highway in the Mojave Desert, California. Four tortoises entered or passed through the culverts on 60 occasions. The system can be easily adapted to other species.

Boarman, W. I.; Beigel, M. L.; Goodlett, G. C.; Sazaki, M.

1999-01-01

259

Heterogeneous personal communications services: integration of PCS systems  

Microsoft Academic Search

Personal communications services (PCS) are being introduced to offer ubiquitous communication. In its first phase PCS consists of a plethora of systems that address cellular, vehicular, cordless phone, and a variety of other services. The integration of these different systems is referred to as “heterogeneous PCS (HPCS)”. We describe the various PCS systems available and address in detail the issue

Yi-Bing Lin; I. Chlamtac

1996-01-01

260

COSMO: a communication scheme for cooperative knowledge-based systems  

Microsoft Academic Search

The purpose of this paper is to present the design principles and features of a communication scheme that has been used to support cooperative problem solving within a network of knowledge-based systems. In presenting this account, we attempt to answer a set of critical yet unsettled questions of cooperative systems communication, such as when and how a knowledge-based system knows

Stephen T. C. Wong

1993-01-01

261

The Study of Human Communication from Three Systems Paradigms.  

ERIC Educational Resources Information Center

There are three general scientific methods for studying the communication process: mechanistic, organic, and systemic. After reviewing the characteristics and research implications of each method, it can be concluded that the systems paradigm is most appropriate to the logic of communication theory. The systems method is defined as a process of…

Monge, Peter R.

262

Trends in Global Nitrous Oxide Emissions from Animal Production Systems  

Microsoft Academic Search

Wastes from animal production systems contribute as much as 30–50% to the global N2O emissions from agriculture, but relatively little attention has been given on improving the accuracy of the estimates and on developing mitigation options. This paper discusses trends and uncertainties in global N2O emission from animal waste and discusses possible mitigation strategies, on the basis of literature data

Oene Oenema; Nicole Wrage; Gerard L. Velthof; Jan Willem van Groenigen; Jan Dolfing; Peter J. Kuikman

2005-01-01

263

Superconductors and cryogenics for future communication systems  

Microsoft Academic Search

In the framework of a German research program on “superconductors and ceramics for future communication technology”, efforts are undertaken to demonstrate the feasibility of cryogenic and high-temperature superconductor technology for applications in communication satellites and base transceiver stations (BTS's) for terrestrial mobile communication. For the receiver front end of C-band satellites, noise reduction filters as well as input-multiplexer channel filters

Matthias Klauda; T. Kasser; B. Mayer; C. Neumann; F. Schnell; B. Aminov; A. Baumfalk; H. Chaloupka; S. Kolesov; H. Piel; N. Klein; S. Schornstein; M. Bareiss

2000-01-01

264

Future Aeronautical Communication System (FACS): Report  

NASA Astrophysics Data System (ADS)

The feasibility of a FACS design, particularly with regard to application possibilities of satellites, was investigated. It was assumed that communication between airborne stations and air traffic control centers is exclusively possible via satellites using mainly voice communication (possibly completed by data communication). It is concluded that integration possibilities of satellites are mainly limited by the airborne antenna chosen. As a solution, phase steered microstrip antenna arrays are presented. However, the use of these antennas is limited to large (long-distance) aircraft. For operational feasibility, it is concluded that communication should take place in the high frequency band.

Hof, H. J.

1985-06-01

265

Expression Systems and Species Used for Transgenic Animal Bioreactors  

PubMed Central

Transgenic animal bioreactors can produce therapeutic proteins with high value for pharmaceutical use. In this paper, we compared different systems capable of producing therapeutic proteins (bacteria, mammalian cells, transgenic plants, and transgenic animals) and found that transgenic animals were potentially ideal bioreactors for the synthesis of pharmaceutical protein complexes. Compared with other transgenic animal expression systems (egg white, blood, urine, seminal plasma, and silkworm cocoon), the mammary glands of transgenic animals have enormous potential. Compared with other mammalian species (pig, goat, sheep, and cow) that are currently being studied as bioreactors, rabbits offer many advantages: high fertility, easy generation of transgenic founders and offspring, insensitivity to prion diseases, relatively high milk production, and no transmission of severe diseases to humans. Noticeably, for a small- or medium-sized facility, the rabbit system is ideal to produce up to 50?kg of protein per year, considering both economical and hygienic aspects; rabbits are attractive candidates for the mammary-gland-specific expression of recombinant proteins. We also reviewed recombinant proteins that have been produced by targeted expression in the mammary glands of rabbits and discussed the limitations of transgenic animal bioreactors.

Wang, Yanli; Zhao, Sihai; Bai, Liang; Fan, Jianglin; Liu, Enqi

2013-01-01

266

Information Retrieval as a ReceiverControlled Communication System.  

National Technical Information Service (NTIS)

Information storage and retrieval systems are characterized as receiver-controlled systems for the communication of information through space and time. The conclusion is reached that in designing, evaluating, or operating an information retrieval system, ...

W. J. Paisley E. B. Parker

1965-01-01

267

Suitability of ANSI standards for quantifying communication satellite system performance  

NASA Technical Reports Server (NTRS)

A study on the application of American National Standards X3.102 and X3.141 to various classes of communication satellite systems from the simple analog bent-pipe to NASA's Advanced Communications Technology Satellite (ACTS) is discussed. These standards are proposed as means for quantifying the end-to-end communication system performance of communication satellite systems. An introductory overview of the two standards are given followed by a review of the characteristics, applications, and advantages of using X3.102 and X3.141 to quantify with a description of the application of these standards to ACTS.

Cass, Robert D.

1988-01-01

268

MSFC Skylab instrumentation and communication system mission evaluation  

NASA Technical Reports Server (NTRS)

An evaluation of the in-orbit performance of the instrumentation and communications systems installed on Skylab is presented. Performance is compared with functional requirements and the fidelity of communications. In-orbit performance includes processing engineering, scientific, experiment, and biomedical data, implementing ground-generated commands, audio and video communication, generating rendezvous ranging information, and radio frequency transmission and reception. A history of the system evolution based on the functional requirements and a physical description of the launch configuration is included. The report affirms that the instrumentation and communication system satisfied all imposed requirements.

Adair, B. M.

1974-01-01

269

Application of Modified ICA to Secure Communications in Chaotic Systems  

Microsoft Academic Search

Along with the increasingly quick development of modern communication system technologies, secure communication has become\\u000a increasingly important. We propose a new method for secure communication systems. Independent component analysis (ICA) is\\u000a employed to retrieve the message signal encrypted by a mixture of Gaussian white noise and chaotic noise. Unlike the traditional\\u000a chaotic synchronization method, this method does not require knowing

Shih-lin Lin; Pi-cheng Tung

2007-01-01

270

The SEA Language for System Engineering and Animation  

Microsoft Academic Search

This paper describes the hierarchical, graphical SEA Language. The SEA Language relies on extended Predicate Transition Nets that unambiguously define the semantics of graphical system specifications. These nets are also used as a basis for simulating\\/animating system specifications. The SEA Language allows to easily incorporate several user defined or standardized graphical symbols and their behaviour. Via this approach a unified

Bernd Kleinjohann; E. Kleinjohann; Jürgen Tacken

1996-01-01

271

Communications and control for electric power systems  

NASA Technical Reports Server (NTRS)

A long-term strategy for the integration of new control technologies for power generation and delivery is proposed: the industry would benefit from an evolutionary approach that would adapt to its needs future technologies as well as those that it has so far not heeded. The integrated operation of the entire system, including the distribution system, was proposed as a future goal. The AbNET communication protocols are reviewed, and additions that were made in 1991 are described. In the original network, traffic was controlled by polling at the master station, located at the substation, and routed by a flooding algorithm. In a revised version, the polling and flooding are modified. The question of interfacing low-energy measurement transducers or instrument transformers is considered. There is presently little or no agreement on what the output of optical current transducers (CT's) should be. Appendices deal with the calibration of current transducers; with Delta modulation, a simple means of serially encoding the output of an OCT; and with noise shaping, a method of digital signal processing that trades off the number of bits in a digital sample for a higher number of samples.

Kirkham, H.

1992-01-01

272

Human body communication system with FSBT  

Microsoft Academic Search

There are some leakage radiations from human body depending on incoming signals to it. As there are many noises in the frequency band spanning several MHz, human body communication (HBC), which is a technique to transfer various information through the human body as a communication channel, requires a limitation of frequencies and data rates to support a reliable network that

Hyung-il Park; In-gi Lim; Sungweon Kang; Whan-woo Kim

2010-01-01

273

Communication architecture tuners: a methodology for the design of high-performance communication architectures for systems-on-chips  

Microsoft Academic Search

In this chapter, we present a general methodology for the design of custom system-on-chip communication architectures. Our technique is based on the addition of a layer of circuitry, called the Communication Architecture Tuner (CAT), around any existing communication architecture topology. The added layer enhances the ability of the system to adapt to changing communication needs of its constituent components. For

Kanishka Lahiri; Anand Raghunathan; Ganesh Lakshminarayana; Sujit Dey

2000-01-01

274

Gas Main Sensor and Communications Network System  

SciTech Connect

Automatika, Inc. was contracted by the Department of Energy (DOE) and with co-funding from the Northeast Gas Association (NGA), to develop an in-pipe natural gas prototype measurement and wireless communications system for assessing and monitoring distribution networks. This projected was completed in April 2006, and culminated in the installation of more than 2 dozen GasNet nodes in both low- and high-pressure cast-iron and steel mains owned by multiple utilities in the northeastern US. Utilities are currently logging data (off-line) and monitoring data in real time from single and multiple networked sensors over cellular networks and collecting data using wireless bluetooth PDA systems. The system was designed to be modular, using in-pipe sensor-wands capable of measuring, flow, pressure, temperature, water-content and vibration. Internal antennae allowed for the use of the pipe-internals as a waveguide for setting up a sensor network to collect data from multiple nodes simultaneously. Sensor nodes were designed to be installed with low- and no-blow techniques and tools. Using a multi-drop bus technique with a custom protocol, all electronics were designed to be buriable and allow for on-board data-collection (SD-card), wireless relaying and cellular network forwarding. Installation options afforded by the design included direct-burial and external polemounted variants. Power was provided by one or more batteries, direct AC-power (Class I Div.2) and solar-array. The utilities are currently in a data-collection phase and intend to use the collected (and processed) data to make capital improvement decisions, compare it to Stoner model predictions and evaluate the use of such a system for future expansion, technology-improvement and commercialization starting later in 2006.

Hagen Schempf

2006-05-31

275

Social media and its dual use in biopreparedness: communication and visualization tools in an animal bioterrorism incident.  

PubMed

This article focuses on social media and interactive challenges for emergency organizations during a bioterrorism or agroterrorism incident, and it outlines the dual-use dilemma of social media. Attackers or terrorists can use social media as their modus operandi, and defenders, including emergency organizations in law enforcement and public and animal health, can use it for peaceful purposes. To get a better understanding of the uses of social media in these situations, a workshop was arranged in Stockholm, Sweden, to raise awareness about social media and animal bioterrorism threats. Fifty-six experts and crisis communicators from international and national organizations participated. As a result of the workshop, it was concluded that emergency organizations can collect valuable information and monitor social media before, during, and after an outbreak. In order to make use of interactive communication to obtain collective intelligence from the public, emergency organizations must adapt to social networking technologies, requiring multidisciplinary knowledge in the fields of information, communication, IT, and biopreparedness. Social network messaging during a disease outbreak can be visualized in stream graphs and networks showing clusters of Twitter and Facebook users. The visualization of social media can be an important preparedness tool in the response to bioterrorism and agroterrorism. PMID:23971817

Sjöberg, Elisabeth; Barker, Gary C; Landgren, Jonas; Griberg, Isaac; Skiby, Jeffrey E; Tubbin, Anna; von Stapelmohr, Anne; Härenstam, Malin; Jansson, Mikael; Knutsson, Rickard

2013-09-01

276

Bonneville Power Administration Communication Alarm Processor expert system:  

SciTech Connect

This report describes the Communications Alarm Processor (CAP), a prototype expert system developed for the Bonneville Power Administration by Oak Ridge National Laboratory. The system is designed to receive and diagnose alarms from Bonneville's Microwave Communications System (MCS). The prototype encompasses one of seven branches of the communications network and a subset of alarm systems and alarm types from each system. The expert system employs a backward chaining approach to diagnosing alarms. Alarms are fed into the expert system directly from the communication system via RS232 ports and sophisticated alarm filtering and mailbox software. Alarm diagnoses are presented to operators for their review and concurrence before the diagnoses are archived. Statistical software is incorporated to allow analysis of archived data for report generation and maintenance studies. The delivered system resides on a Digital Equipment Corporation VAX 3200 workstation and utilizes Nexpert Object and SAS for the expert system and statistical analysis, respectively. 11 refs., 23 figs., 7 tabs.

Goeltz, R.; Purucker, S.; Tonn, B. (Oak Ridge National Lab., TN (USA)); Wiggen, T. (Oak Ridge Associated Universities, Inc., TN (USA)); MacGregor, D. (MacGregor-Bates, Inc., Eugene, OR (USA))

1990-06-01

277

Response to a Community-Based Information and Communication System.  

ERIC Educational Resources Information Center

A study investigated the introduction of an experimental school-centered and neighborhood-oriented communication system in a small midwestern town. It was anticipated that normal parent-teacher-school communication would be enhanced by the electronic messaging potential of the system. Researchers observed the entire adoption process from the…

Trachtman, Leon E.; And Others

278

Documenting Changes in Communication Behaviours Using a Structured Observation System  

ERIC Educational Resources Information Center

The Structured Observation System (SOS) is a data collection method developed to document changes in the communication behaviours of children identified with speech and language delays. The system employs a rating scale which reflects the occurrence of communication behaviours as well as the amount of assistance needed for behaviours to occur.…

Reading, Suzanne; Richie, Carolyn

2007-01-01

279

Optical Fiber Feeder for Microcellular Mobile Communication Systems (H-015)  

Microsoft Academic Search

The authors investigate the feasibility of using an optical fiber feeder for microcellular mobile communication systems. The optical feeder enables compact and low-cost base stations, easy radio channel control, and flexible mobile communication systems. Basic transmission characteristics were investigated through optical transmission experiments. Using these results, it is estimated that the optical feeder can transmit 880 telephone channels for digital

Makoto Shibutani; Toshihito Kanai; Watani Domom; Katsumi Emura; Junji Namiki

1993-01-01

280

Putting innovation to work: adoption strategies for multimedia communication systems  

Microsoft Academic Search

Multimedia communication systems promise better support for widely distributed workgroups. Their benefits for complex communication—problem-solving, negotiating, planning, and design —seem obvious, introducing appealing new technologies into the marketplace, however, can require years of Investment [13, 22]. In particular, finding productive uses for new systems takes time. Adoption strategies are needed to guide and accelerate the process.

Ellen Francik; Susan Ehrlich Rudman; Donna Cooper; Stephen Levine

1991-01-01

281

Timing acquisition in ultra-wideband communication systems  

Microsoft Academic Search

The goal of this paper is to highlight the significance of the timing acquisition problem in ultra-wideband (UWB) communication systems and discuss efficient solutions to the problem. We discuss how the distinguishing features of UWB communication systems, such as their wide bandwidth and low transmission power constraints, are responsible for making the acquisition of UWB signals a difficult task. A

Sandeep R. Aedudodla; Saravanan Vijayakumaran; Tan F. Wong

2005-01-01

282

An optimal estimation algorithm for multiuser chaotic communications systems  

Microsoft Academic Search

In a multiuser chaotic communications scheme, each user's information is modulated with a different chaotic system and then transmitted independently. However, the receiver sees the superposition of these signals with additional noise. In this paper, a novel optimal estimation algorithm for such multiuser chaotic communications systems is presented. The goal is to estimate the chaotic signal being sent by each

M. Cifici; Douglas B. Williams

2002-01-01

283

The Cost of Adding Security Services to Group Communication Systems  

Microsoft Academic Search

Numerous applications requiring information delivery from one sender to many receivers are based on a group communication model. Group communication systems are used in industry and military systems where relia- bility and high-availability are required. With the growth of the Internet, the number of applications that can take advantage of a group communicationinfrastructure increased (teleconferences, white-boards, video confer- ences, distributed

Cristina Nita-Rotaru; Yair Amir

2000-01-01

284

The global minima of the communicative energy of natural communication systems  

NASA Astrophysics Data System (ADS)

Until recently, models of communication have explicitly or implicitly assumed that the goal of a communication system is just maximizing the information transfer between signals and 'meanings'. Recently, it has been argued that a natural communication system not only has to maximize this quantity but also has to minimize the entropy of signals, which is a measure of the cognitive cost of using a word. The interplay between these two factors, i.e. maximization of the information transfer and minimization of the entropy, has been addressed previously using a Monte Carlo minimization procedure at zero temperature. Here we derive analytically the globally optimal communication systems that result from the interaction between these factors. We discuss the implications of our results for previous studies within this framework. In particular we prove that the emergence of Zipf's law using a Monte Carlo technique at zero temperature in previous studies indicates that the system had not reached the global optimum.

Cancho, Ramon Ferrer i.; Díaz-Guilera, Albert

2007-06-01

285

Transgenic animal assay system for anti-cholinesterase substances  

US Patent & Trademark Office Database

The present invention provides a transgenic animal assay system which provides a model system for testing for, and treatment of, cholinergic deficits and imbalances in mammals such as cognitive functioning in Alzheimer's patients, certain types of retinal photoreceptor degeneration, hematopoietic disorders, and screening for and susceptibility to anti-cholinesterase compounds. The transgenic animals and progeny thereof are transformed with a recombinant expression vector of the present invention. The recombinant expression vector comprises a DNA sequence encoding a heterologous cholinesterase (ChE) enzyme and promoter.

2000-02-15

286

Iridium{reg_sign} worldwide personal communication system  

SciTech Connect

The IRIDIUM system is a personal worldwide communication system designed to support portable, low power subscriber units through the use of a constellation of satellites in low earth polar orbit. The satellites are networked together to form a system which provides continuous line-of-sight communications between the IRIDIUM system and any point within 30 km of the earth{close_quote}s surface. The system architecture and operation are described. {copyright} {ital 1997 American Institute of Physics.}

Helm, J. [Senior Systems Engineer Motorola Mobile Satellite Systems Division 1600 W. Chandler Blvd., Suite 150 Chandler, Arizona85224 (United States)

1997-01-01

287

ASTP communications systems analyses and performance predictions  

NASA Technical Reports Server (NTRS)

A research program was conducted to provide ASTP mission communication coverage and performance analyses and to analyze anomalies and special compatibility problems as they arise. The end product of the contract was spacecraft-to-ground communications performance predictions for the ASTP mission, both for direct communication links to ground and for those links via the ATS-6 relay satellite to ground. Solutions are given for the special mission anomalies and compatibility problems encountered. A brief summary describing the work activities expended is given.

1975-01-01

288

Defense satellite communications system - Past, present, and future  

NASA Astrophysics Data System (ADS)

This is a critical point in the long history of the Defense Satellite Communications System. This workhorse communications system has developed from the humble beginnings in the 1960s into today's highly capable backbone of U.S. Government Communications. After a long delay these satellites are being launched again and plan to quickly rebuild this critical national asset which has been held together by determination and sweat following the Challenger disaster. The critical issue is what services shall DSCS provide in the future. The process of defining the SHF communications capability of the next generation of these satellites to support the military needs of the next century is under way.

Cook, Robert G.

1992-03-01

289

LAN based data communication in modern energy management systems (EMS)  

SciTech Connect

The use of energy management systems (EMS) demands high reliability, real-time behavior and more and more economical systems. The last demand requires use of inexpensive standard components, whenever possible. The following article discusses realization of EMS, especially system communication, with respect to these constraints. Problems due to conventional use of standardized communication protocols in distributed supervisory systems in general and highly-reliable systems in particular are shown. Multicast communication concepts are presented as solutions, using standardized protocols in a problem specific way. The presented concepts fulfill the necessity of using standard components as well as the specific demands towards EMS.

Dieterle, W.; Kochs, H.D. [Univ. of Duisburg (Germany). Dept. of Computer Science] [Univ. of Duisburg (Germany). Dept. of Computer Science; Dittmar, E. [ABB Netzleittechnik Gmbh, Ladenburg (Germany)] [ABB Netzleittechnik Gmbh, Ladenburg (Germany)

1996-02-01

290

The Communications link analysis and simulation system (CLASS)  

NASA Technical Reports Server (NTRS)

The Communications Link Analysis and Simulation System (CLASS) is a comprehensive, computerized communications and tracking system analysis tool under development by the Networks Directorate of the NASA/GSFC. The primary use of this system is to provide the capability to predict the performance of the Tracking and Data Relay Satellite system (TDRSS) User Communications and Tracking links through the TDRSS. The general capabilities and operational philosophy of the current and final versions of the CLASS are described along with some examples of analyses which have been performed utilizing the capabilities of this system.

Godfrey, R. D.

1985-01-01

291

The ESA technological development activity for domestic communications satellite systems  

NASA Astrophysics Data System (ADS)

Domestic and rural satellite communications, when compared to more traditional satellite systems such as Intelsat and Eutelsat, present different system requirements which result in different technological solutions both for the space segment and the ground segment. In view of preparing European industry to be competitive in an international 'Call for Tenders' expected for such systems, especially from less developed countries, the European Space Agency started in 1982 a program of technological development of specific components, subsystems, and systems described in this communication. After introducing background concepts of Domestic Communication Satellite Systems, the article reviews the technological developments in both the space segment and the earth segment.

Bichi, A. F.

1986-10-01

292

Electrical Protection of Tactical Communication Systems.  

National Technical Information Service (NTIS)

The manual covers the subject of electrical protection with sufficient thoroughness to enable the communications engineer to evaluate the probable extent of a protection problem and to develop protection measures that are not only effective but also in ec...

D. W. Bodie J. B. Hays

1964-01-01

293

Analysis of Maritime Mobile Satellite Communication Systems.  

National Technical Information Service (NTIS)

The communication channel between a satellite and a ship earth station (SES) is described by a model which includes multipath fading, doppler shift and noise. Multipath fading is caused by reflections from the sea surface. These reflections can affect the...

A. J. Zapata

1988-01-01

294

The modeling and Analysis of Data Communication System (DCS) in Communication Based Train Control (CBTC) with Colored Petri Nets  

Microsoft Academic Search

Communication based train control (CBTC) system was based on mobile communication and overcome fixed blocks in order to increase track utilization and train safety. As an intelligent autonomous decentralized systems (IADS), data communication system (DCS) between trains and zone center (ZC) are crucial factors for the safe and efficient operation of CBTC system. The real-time behavior under various transmission conditions

Tianhua Xu; Tao Tang

2007-01-01

295

Developing an Approach for Analyzing and Verifying System Communication  

NASA Technical Reports Server (NTRS)

This slide presentation reviews a project for developing an approach for analyzing and verifying the inter system communications. The motivation for the study was that software systems in the aerospace domain are inherently complex, and operate under tight constraints for resources, so that systems of systems must communicate with each other to fulfill the tasks. The systems of systems requires reliable communications. The technical approach was to develop a system, DynSAVE, that detects communication problems among the systems. The project enhanced the proven Software Architecture Visualization and Evaluation (SAVE) tool to create Dynamic SAVE (DynSAVE). The approach monitors and records low level network traffic, converting low level traffic into meaningful messages, and displays the messages in a way the issues can be detected.

Stratton, William C.; Lindvall, Mikael; Ackermann, Chris; Sibol, Deane E.; Godfrey, Sally

2009-01-01

296

Performance of Digital Communication Systems with Adaptive Arrays.  

National Technical Information Service (NTIS)

This report examines the protection offered to digital communication systems by the LMS adaptive array. The performances of systems that use binary phase-shift-keyed (BPSK), quadrature phase-shifted-keyed (QPSK), binary differential phase-shift-keyed (DPS...

M. W. Ganz

1986-01-01

297

PM: An Operating System Coordinated High Performance Communication Library  

Microsoft Academic Search

. We have developed a new communication library, called PM,for the Myrinet gigabit LAN card, that has a dedicated processor andon-board memory to handle a communication protocol. In order to obtainhigh performance communication and support a multi-user environment,we have co-desgined PM, an operating system realized by adaemon process, and the run-time routine for a programming language.Several unique features, e.g., network

Hiroshi Tezuka; Atsushi Hori; Yutaka Ishikawa; Mitsuhisa Sato

1997-01-01

298

Communication and remote control approaches to road surface carrying system  

NASA Astrophysics Data System (ADS)

In this paper, we present a novel control approach which is fusion techniques of factory automation/management and functions of hardware for computer communication. We describe the communication techniques between computer and programmable logic controller based on special system protocols. The developed controller innovated prior knowledge from some files, is considered as guides for the relevant controller designers and programmers, and a reference on establishing practical database for intelligent agents and on communication tasks.

Wang, Xin; Wang, Jin

2013-07-01

299

Coded error probability evaluation for antijam communication systems  

NASA Technical Reports Server (NTRS)

We present a general union-Chernoff bound on the bit error probability for coded communication systems and apply it to examples of antijam systems. The key feature of this bound is the decoupling of the coding aspects of the system from the remaining part of the communication system which includes jamming, suboptimum detectors, and arbitrary decoding metrics which may or may not use jammer state knowledge

Omura, J. K.; Levitt, B. K.

1982-01-01

300

An Efficient Symbolic Interface to Constraint Based Animation Systems  

Microsoft Academic Search

Symbolic methods have been used to provide a general user interface in optimization based animation systems. However, previous methods suffer from the exponential growth in the length of the symbolic expressions of the objectives, constraints and their derivatives. In this paper,we present a symbolic language which is general enough to represent common kinematic and dynamic quantities. The evaluation of these

Zi-cheng Liu; Michael F. Cohen

1994-01-01

301

An Efficient Symbolic Interface to Constraint Based Animation Systems  

Microsoft Academic Search

Symbolic methods have been used to provide a general user interface in optimization based animation systems. However, previous methods suffer from the exponential growth in the length of the symbolic expressions of the objectives, constraints and their derivatives. In this paper, we present a symbolic language which is general enough to represent common kinematic and dynamic quantities. The evaluation of

Michael F. Cohen; Zicheng Liu

1995-01-01

302

A System for Developing Microwave Induced Hyperthermia in Small Animals  

Microsoft Academic Search

A system for developing microwave induced hyperthermia in small animals is described, for the purpose of assessing the effects of heat alone and heat plus ionizing radiation on normal tissue and tumors. The temperature is monitored using thermistors, and with the use of a scanner, recorded on a single channel recorder. The thermometry technique is still under review. Thermographic studies

Robert J. Baker; Vernon Smith; Theodore L. Phillips; Lan Kobe; Larry Kane

1977-01-01

303

Virtual Mechanics Simulation and Animation of Rigid Body Systems  

Microsoft Academic Search

The animation system AERO is presented in this paper. It allows the creation of virtual envi- ronments from scenes with simple three-dimensional geometrical objects (sphere, cylinder, box, point, plane). Objects can be linked to each other by a variety of methods (rod, spring, damper, joint). Realistic object movements are achieved by a simulation procedure, where forces can be applied to

Hartmut Keller; Horst Stolz; Andreas Ziegler; Thomas Bräunl

1994-01-01

304

DESIGN PARAMETERS FOR ANIMAL WASTE TREATMENT SYSTEMS - NITROGEN CONTROL  

EPA Science Inventory

The objectives of this study were to: (a) Develop design criteria for nitrogen and odor control in animal waste stabilization systems; (b) demonstrate the feasibility of nitrogen control using the oxidation ditch; (c) determine the rate, form, and time of manure application permi...

305

Small Animal PET: A Review of Commercially Available Imaging Systems  

Microsoft Academic Search

More than ten years ago, several research groups started to develop Positron Emission Tomography (PET) systems dedicated to animal studies. The growing interest in pre-clinical imaging studies, both in biological and medical basic research, and in pharmaceutica l industry, has recently induced the world-leading manufacturers of medical image equipment to invest in this market. Some of the proposed scanner prototypes

Michele Larobina; Arturo Brunetti; Marco Salvatore

2006-01-01

306

Satellite communications systems and technology. Volume 1: Analytical chapters  

NASA Technical Reports Server (NTRS)

This is Volume 1 (Analytical Chapters) of the final report of the NASA/NSF Panel Satellite Communications Systems and Technology. The panel surveyed advanced technology being developed for commercial use in the satellite communications field in Europe, Japan, and Russia. All aspects of satellite communications were considered, including fixed, broadcast, mobile, personal communications, navigation, low earth orbit, and small satellites. The focus was on experimental and advanced technology being developed in R&D and demonstration programs rather than on today's production capabilities. Focus was on commercial satellite technology, and does not review defense-related or other confidential satellite communications capabilities. The NASA/NSF panel concluded that the United States has lost its leading position in many critical satellite communications technologies. Although U.S. industry retains a leading position in today's marketplace for satellite communications systems and services, this position is largely founded on technologies and capabilities developed in the 1960's and 1970's. Because the United States is losing ground with respect to a wide range of technologies and systems that will be key to future communications markets, the market share of the U.S. satellite communications industry is at risk.

Edelson, Burton I. (editor); Pelton, Joseph N. (editor); Bostian, Charles W.; Brandon, William T.; Chan, Vincent W. S.; Hager, E. Paul; Helm, Neil R.; Jennings, Raymond D.; Kwan, Robert K.; Mahle, Christoph E.

1993-01-01

307

Satellite communications systems and technology. Volume 1; Analytic Chapters  

NASA Technical Reports Server (NTRS)

Volume 1 (Analytical Chapters) of the final report of the NASA/NSF Panel Satellite Communications Systems and Technology is presented. The panel surveyed advanced technology being developed for commercial use in the satellite communications field in Europe, Japan, and Russia. All aspects of satellite communications were considered, including fixed, broadcast, mobile, personal communications, navigation, low earth orbit, and small satellites. The focus of the study was on experimental and advanced technology being developed in R&D and demonstration programs rather than on today's production capabilities. The report focuses on commercial satellite technology, and does not review defense-related or other confidential satellite communications capabilities. The NASA/NSF panel concluded that the United States has lost its leading position in many critical satellite communications technologies. Although U.S. industry retains a leading position in today's marketplace for satellite communications systems and services, this position is largely founded on technologies and capabilities developed in the 1960s and 1970s. Because the United States is losing ground with respect to a wide range of technologies and systems that will be key to future communications markets, the market share of the U.S. satellite communications industry is at risk.

Jennings, Raymond D.; Mahle, Christoph E.; Miller, Edward F.; Riley, Lance; Pelton, Joseph N.; Bostian, Charles W.; Brandon, William T.; Chan, Vincent W. S.; Hager, E. Paul; Edelson, Burton I.; Kwan, Robert K.; Helm, Neil R.

1993-01-01

308

Satellite communications systems and technology. Volume 1: Analytical chapters  

NASA Astrophysics Data System (ADS)

This is Volume 1 (Analytical Chapters) of the final report of the NASA/NSF Panel Satellite Communications Systems and Technology. The panel surveyed advanced technology being developed for commercial use in the satellite communications field in Europe, Japan, and Russia. All aspects of satellite communications were considered, including fixed, broadcast, mobile, personal communications, navigation, low earth orbit, and small satellites. The focus was on experimental and advanced technology being developed in R&D and demonstration programs rather than on today's production capabilities. Focus was on commercial satellite technology, and does not review defense-related or other confidential satellite communications capabilities. The NASA/NSF panel concluded that the United States has lost its leading position in many critical satellite communications technologies. Although U.S. industry retains a leading position in today's marketplace for satellite communications systems and services, this position is largely founded on technologies and capabilities developed in the 1960's and 1970's. Because the United States is losing ground with respect to a wide range of technologies and systems that will be key to future communications markets, the market share of the U.S. satellite communications industry is at risk.

Edelson, Burton I.; Pelton, Joseph N.; Bostian, Charles W.; Brandon, William T.; Chan, Vincent W. S.; Hager, E. Paul; Helm, Neil R.; Jennings, Raymond D.; Kwan, Robert K.; Mahle, Christoph E.

1993-07-01

309

Communications system having optical transmission line switching system  

US Patent & Trademark Office Database

A communications system includes a plurality of optical transmission lines in an active system and an optical transmission line in a protection system, and transmitter/receiver devices connected to respective ends of the optical transmission lines. The transmitter/receiver devices respectively include a first interface unit for establishing a first interface with signal transmission lines, a second interface unit for establishing a second interface with one of the optical transmission lines, a first multiplexer/demultiplexer unit for executing a first multiplexing and demultiplexing operation, and a second multiplexer/demultiplexer unit for executing a second multiplexing and demultiplexing operation. Further, the transmitter/receiver devices respectively include a switching unit, which is provided between the first and second multiplexer/demultiplexer units, for selectively coupling the first multiplexer/demultiplexer units in the active system with the first multiplexer/demultiplexer units in the protection system by means of optical fiber cables.

1995-07-18

310

Satellite communications systems and technology. Volume 2; Site Reports  

NASA Technical Reports Server (NTRS)

Volume 2 of the final report of the NASA/NSF Panel on Satellite Communications Systems and Technology is presented. It consists of the site reports from the panel's visits to satellite communications facilities and laboratories in Europe, Japan, and Russia.

Edelson, Burton I.; Pelton, Joseph N.; Bostian, Carles W.; Brandon, William T.; Chan, Vincent W. S.; Hager, E. Paul; Helm, Neil R.; Jennings, Raymond D.; Kwan, Robert K.; Mahle, Christoph E.; Miller, Edward F.; Riley, Lance

1993-01-01

311

The Use of Multiple Communication in Systemic Couples Therapy.  

ERIC Educational Resources Information Center

Presents a clinical technique for working with troubled couples based on a particular theory of multiple communication in therapy. The technique, a "systemic couples reversal," prescribes a way of managing the multiple communications of stability, change, and meaningful Rorschach. Provides a theoretical map, clinical procedure, and clinical case…

Keeney, Bradford P.; Siegel, Stanley

1986-01-01

312

An Experimental Study of the Emergence of Human Communication Systems  

ERIC Educational Resources Information Center

The emergence of human communication systems is typically investigated via 2 approaches with complementary strengths and weaknesses: naturalistic studies and computer simulations. This study was conducted with a method that combines these approaches. Pairs of participants played video games requiring communication. Members of a pair were…

Galantucci, Bruno

2005-01-01

313

Solar-Powered Laser Communications System for Space.  

National Technical Information Service (NTIS)

Space communications with the Nd:YAG laser offers extended operating life due to the use of direct solar pumping of the laser. Solar radiation is converted directly to laser light. A laser communications system now in final development will allow the tran...

J. D. Barry

1977-01-01

314

Systemic indicators of inorganic arsenic toxicity in four animal species.  

PubMed

The effect of arsenic compounds depends on the chemical form and is specific for certain organs. The lack of specific biological indicators for the effects of each arsenic species makes it difficult to differentiate their toxicity. Five prospective biological indicators of systemic toxicity were examined at time points ranging from 15 min to 24 h using male Sprague-Dawley rats, B6C3F1 mice, Golden-Syrian hamsters, and Hartley guinea pigs, following intraperitoneal dosing with 0.1 and 1 mg/kg sodium arsenite. Rats and mice were also dosed with 1 mg/kg sodium arsenate. Total blood arsenic levels were determined in all animal species to show that exposure occurred and as an index of the severity of the change is an indicator of toxicity. Total blood arsenic levels were increased in all animal species. This increase was dose, arsenic species, and animal dependent. Renal pyruvate dehydrogenase activity was significantly decreased at early time points in mice, hamsters, and guinea pigs, and at later time points in rats dosed with arsenite. Rats and mice dosed with arsenate also exhibited PDH decrease at early time points. Blood hematocrit and glucose were increased in the rat and guinea pig, respectively, after arsenite administration. Creatinine and urea nitrogen were found to be unresponsive to arsenic in most animal species. Data suggested that the mouse and secondly the hamster appear to be the most appropriate animal models for the study of acute arsenic toxicity. PMID:10653439

Mitchell, R D; Ayala-Fierro, F; Carter, D E

2000-01-28

315

Theatre of the Mind: A Project to Animate the Language of thought and Communication  

ERIC Educational Resources Information Center

Human language is a rich and complex part of human behaviour that can be studied in many ways. The author and his colleagues are developing an application that accepts simple texts as input and presents an animated display of characters acting out the text. It mimics the human visualization of texts, the so-called Theatre of the Mind. In so doing,…

Wheeler, Eric S.

2009-01-01

316

ATCOM: Automatically Tuned Collective Communication System for SMP Clusters  

SciTech Connect

Conventional implementations of collective communications are based on point-to-point communications, and their optimizations have been focused on efficiency of those communication algorithms. However, point-to-point communications are not the optimal choice for modern computing clusters of SMPs due to their two-level communication structure. In recent years, a few research efforts have investigated efficient collective communications for SMP clusters. This dissertation is focused on platform-independent algorithms and implementations in this area. There are two main approaches to implementing efficient collective communications for clusters of SMPs: using shared memory operations for intra-node communications, and overlapping inter-node/intra-node communications. The former fully utilizes the hardware based shared memory of an SMP, and the latter takes advantage of the inherent hierarchy of the communications within a cluster of SMPs. Previous studies focused on clusters of SMP from certain vendors. However, the previously proposed methods are not portable to other systems. Because the performance optimization issue is very complicated and the developing process is very time consuming, it is highly desired to have self-tuning, platform-independent implementations. As proven in this dissertation, such an implementation can significantly out-perform the other point-to-point based portable implementations and some platform-specific implementations. The dissertation describes in detail the architecture of the platform-independent implementation. There are four system components: shared memory-based collective communications, overlapping mechanisms for inter-node and intra-node communications, a prediction-based tuning module and a micro-benchmark based tuning module. Each component is carefully designed with the goal of automatic tuning in mind.

Meng-Shiou Wu

2005-12-17

317

Secure electronic commerce communication system based on CA  

NASA Astrophysics Data System (ADS)

In this paper, we introduce the situation of electronic commercial security, then we analyze the working process and security for SSL protocol. At last, we propose a secure electronic commerce communication system based on CA. The system provide secure services such as encryption, integer, peer authentication and non-repudiation for application layer communication software of browser clients' and web server. The system can implement automatic allocation and united management of key through setting up the CA in the network.

Chen, Deyun; Zhang, Junfeng; Pei, Shujun

2001-07-01

318

60GHz Monolithic LTCC Module for Wireless Communication Systems  

Microsoft Academic Search

A highly integrated RF module, the so-called system-on-package module, which employs a multi-layer structure, is effective in achieving high-speed wireless communication systems that have a transmission rate higher than 1 Gb\\/s at millimeter-wave frequencies. We present a 12times12times1.2 mm3 compact monolithic low temperature co-fired ceramic (LTCC) transmitter module for 60-GHz wireless communication systems. The MMIC includes the power amplifier circuit,

T. Seki; K. Nishikawa; Y. Suzuki; I. Toyoda; K. Tsunekawa

2006-01-01

319

A Study on Communication Issues for Systems-on-Chip  

Microsoft Academic Search

Present days cores composing a System-on-Chip might be interconnected by means of both dedicated channels or shared buses. Nevertheless, future systems will have strong requirements on reusability and communication performance, which will constrain the use of such interconnect systems. An emerging approach, the Networks-on-Chip (NOCs), will potentially fulfill those requirements, because NOCs are reusable and their communication performance gracefully scales

Cesar A. Zeferino; Márcio E. Kreutz; Luigi Carro; Altamiro A. Susin

2002-01-01

320

Multiple-antenna communication systems: an emerging technology  

Microsoft Academic Search

A recent development in wireless communications is the application of multiple-input multiple-output (MIMO) systems to radio communications via use of multiple antennas. In order to investigate the technologys potential, an experimental MIMO system containing two four-element antenna arrays (4x4) has been developed at the University of Alberta. The system is used to obtain MIMO channel measurements in a typical indoor

Paul Goud Jr; Christian Schlegel; W. A. Krzymien; Robert Hang

2004-01-01

321

Towards the next generation of nanosatellite communication systems  

NASA Astrophysics Data System (ADS)

The communication systems currently used on nanosatellites are usually well-proven commercial-off-the-shelf units with data rates up to 9.6 kbit/s. A careful analysis shows that by using advancements in microelectronics, a higher communication performance can be achieved, even within the power and mass limitations of a nanosatellite. This paper presents a new approach to maximize the performance of nanosatellite communication systems by taking a systems engineer's perspective and by regarding the entire satellite instead of the communication system only. It is found that efficiency can be gained by also including the electrical power subsystem in the design and having a strong interaction between the communication subsystem and the electrical power subsystem. The parameters that influence the performance of the communication system are identified. It is shown how these parameters can be tuned such that the limited resources on a nanosatellite are used most effectively. The results are used in designing the communication system of Delfi-n3Xt, the next nanosatellite mission of Delft University of Technology. The results presented in the paper can be used as a guideline to designing a nanosatellite of the next generation.

de Milliano, Martijn; Verhoeven, Chris

2010-05-01

322

Facility for the evaluation of space communications and related systems  

NASA Technical Reports Server (NTRS)

NASA Lewis Research Center's Communications Projects Branch has developed a facility for the evaluation of space communications systems and related types of systems, called the Advanced Space Communications (ASC) Laboratory. The ASC Lab includes instrumentation, testbed hardware, and experiment control and monitor software for the evaluation of components, subsystems, systems, and networks. The ASC lab has capabilities to perform radiofrequency (RF), microwave, and millimeter-wave characterizations as well as measurements using low, medium, or high data rate digital signals. In addition to laboratory measurements, the ASC Lab also includes integrated satellite ground terminals allowing experimentation and measurements accessing operational satellites through real space links.

Kerczewski, Robert J.; Svoboda, James S.; Kachmar, Brian A.

1995-01-01

323

High capacity satellite communication system and key technologies  

NASA Astrophysics Data System (ADS)

A high-capacity satellite communication system for Japan, with multiple beams and key technologies for onboard equipment, is described. The system will provide trunk transmission, digital business communication, and mobile communication. Advantages of the multibeam system include increased transmission capacity, reduction in earth-station antenna diameter, and frequency reuse. Onboard technologies discussed include cluster-feed horn design, reflector deployment, antenna pointing control (accurate to 0.015 degree with 0.3-degree spot width for the 12 beams), satellite switch, and onboard receiver and transmitter.

Nagai, Y.; Okasaka, S.; Nakagawa, K.

324

Synchronization of randomly multiplexed chaotic systems with application to communication.  

PubMed

Synchronized chaotic systems have recently been applied to the area of secure communications in a variety of ways. At the same time, there have also been significant advances in deciphering messages masked by chaotic signals. It is important, therefore, to explore more secure approaches to using chaos in communication. We show that multiple chaotic systems can be synchronized through a scalar coupling which carries a stochastic signal generated by random multiplexing of the source systems. This approach, which is a variant of the active-passive decomposition method, promises enhanced security in chaos-based communication. PMID:11136020

Sundar, S; Minai, A A

2000-12-18

325

Ship-Shore Packet Switched Communications System.  

National Technical Information Service (NTIS)

This thesis presents an architecture for ship-shore sea service communications. Starting with the ARPANET packet switching model (TCP/IP), Network and Logical Link layers are defined which deal with the following problems: (1) Many ship-shore links are on...

R. A. Buddenberg

1986-01-01

326

Communication System for Remote Processor Control.  

National Technical Information Service (NTIS)

The PDP11/35 computer is well suited to time-sharing operations but not long numerical analysis problems. Since an Interdata 7/32 has strengths complementary to the PDP11, a communications link between the two computers would have numerous advantages. Thi...

P. R. Bernstein

1977-01-01

327

A Systems Approach to Scaffold Communication Skills Development  

PubMed Central

Objectives To implement a communication skills development (CSD) system and evaluate its effectiveness in a clinical communications course. Design Students conducted baseline interviews and wrote SOAP notes, and based on faculty, patient, self- and peer assessments, set goals for improvement of their communication skills. Students participated in various activities to scaffold their learning, several of which took place in a web-based environment to enhance access and function for both students and faculty members. Quantitative and qualitative analyses were performed. Assessment Students' communication skills improved as evidenced by assessment scores. Student and faculty comments offered additional evidence of the effectiveness of standardized patient interviews, learning strategies, and assessment methods. Conclusion The CSD system effectively integrated various types of learning activities and feedback processes. The use of scaffolding strategies appeared to enhance the development of students' communication skills.

Er, Nelson L.

2008-01-01

328

75 FR 8400 - In the Matter of Certain Wireless Communications System Server Software, Wireless Handheld...  

Federal Register 2010, 2011, 2012, 2013

...Wireless Communications System Server Software, Wireless Handheld Devices and Battery...wireless communications system server software, wireless handheld devices and battery...wireless communications system server software, wireless handheld devices or...

2010-02-24

329

78 FR 31576 - Enforcement Proceeding; Certain Two-Way Global Satellite Communication Devices, System and...  

Federal Register 2010, 2011, 2012, 2013

...Proceeding; Certain Two-Way Global Satellite Communication Devices, System and Components...importation of certain two-way global satellite communication devices, system and components...after importation any two-way global satellite communication devices, system,...

2013-05-24

330

NASA Workshop on Animal Gravity-Sensing Systems  

NASA Technical Reports Server (NTRS)

The opportunity for space flight has brought about the need for well-planned research programs that recognize the significance of space flight as a scientific research tool for advancing knowledge of life on Earth, and that utilize each flight opportunity to its fullest. For the first time in history, gravity can be almost completely eliminated. Thus, studies can be undertaken that will help to elucidate the importance of gravity to the normal functioning of living organisms, and to determine the effects microgravity may have on an organism. This workshop was convened to organize a plan for space research on animal gravity-sensing systems and the role that gravity plays in the development and normal functioning of these systems. Scientists working in the field of animal gravity-sensing systems use a wide variety of organisms in their research. The workshop presentations dealt with topics which ranged from the indirect gravity receptor of the water flea, Daphnia (whose antennal setae apparently act as current-sensing receptors as the animal moves up and down in water), through specialized statocyst structures found in jellyfish and gastropods, to the more complex vestibular systems that are characteristic of amphibians, avians, and mammals.

Corcoran, M. L. (editor)

1986-01-01

331

National Animal Identification System (NAIS): Why Animal Identification; Why Now; What First.  

National Technical Information Service (NTIS)

A rational, cost-effective animal identification program will enhance foreign animal disease surveillance, control, and eradication; facilitate epidemiologic investigations; improve biosecurity protection of the national livestock population; distinguish ...

2004-01-01

332

21 CFR 892.2050 - Picture archiving and communications system.  

Code of Federal Regulations, 2011 CFR

... Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.2050 Picture archiving and communications system. (a)...

2011-04-01

333

21 CFR 892.2050 - Picture archiving and communications system.  

Code of Federal Regulations, 2012 CFR

... Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.2050 Picture archiving and communications system. (a)...

2012-04-01

334

21 CFR 892.2050 - Picture archiving and communications system.  

... Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.2050 Picture archiving and communications system. (a)...

2014-04-01

335

7. Survivable low frequency communication system pathway, looking east ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

7. Survivable low frequency communication system pathway, looking east - Ellsworth Air Force Base, Delta Flight, Launch Control Facility, County Road CS23A, North of Exit 127, Interior, Jackson County, SD

336

80. Survivable lowfrequency communications system receiver, teletypewriter set, radio, teleprinter, ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

80. Survivable low-frequency communications system receiver, teletypewriter set, radio, teleprinter, south side - Ellsworth Air Force Base, Delta Flight, Launch Control Facility, County Road CS23A, North of Exit 127, Interior, Jackson County, SD

337

Structuring computer-mediated communication systems to avoid information overload  

Microsoft Academic Search

Unless computer-mediated communication systems are structured, users will be overloaded with information. But structure should be imposed by individuals and user groups according to their needs and abilities, rather than through general software features.

Starr Roxanne Hiltz; Murray Turoff

1985-01-01

338

Some Stochastic Control Problems in Manufacturing, Communications and Computer Systems.  

National Technical Information Service (NTIS)

This document examined the following problems: 1) Routing and optimal scheduling in communication networks; 2) Optimal scheduling of failure prone flexible manufacturing systems; 3) Determining when zero-inventory policies are optimal; 4) Characterizing w...

P. R. Kumar

1988-01-01

339

46 CFR 121.602 - Internal communications systems.  

Code of Federal Regulations, 2013 CFR

...station to the location where the means of controlling the propulsion machinery, required by § 121.620(a), is located. Twin screw vessels with pilothouse control for both engines are not required to have a fixed communications system. (b)...

2013-10-01

340

Spatial Transmit/Receive Isolation Method for Optical Communication Systems.  

National Technical Information Service (NTIS)

Apparatus, and a corresponding method, for spatially isolating a transmit beam and a receive beam, which, in satellite communication systems, are inherently separated by a look ahead angle. A receive beam separation mirror is positioned in the receive bea...

D. P. Dixon K. D. Ngo S. B. Schrier

2004-01-01

341

S-Band Antenna Phased Array Communications System.  

National Technical Information Service (NTIS)

The development of an S-band antenna phased array for spacecraft to spacecraft communication is discussed. The system requirements, antenna array subsystem design, and hardware implementation are examined. It is stated that the phased array approach offer...

D. R. Delzer J. E. Chapman R. A. Griffin

1975-01-01

342

National Science Foundation Division Plan: Electrical, Communications and Cyber Systems.  

National Technical Information Service (NTIS)

The Division of Electrical, Communications and Cyber Systems (ECCS) of the National Science Foundation (NSF) addresses fundamental research issues underlying device and component technologies, power and energy, controls, computation, networks, communicati...

U. Varshney

2008-01-01

343

21 CFR 892.2050 - Picture archiving and communications system.  

Code of Federal Regulations, 2013 CFR

... Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.2050 Picture archiving and communications system. (a)...

2013-04-01

344

Cultural selection drives the evolution of human communication systems.  

PubMed

Human communication systems evolve culturally, but the evolutionary mechanisms that drive this evolution are not well understood. Against a baseline that communication variants spread in a population following neutral evolutionary dynamics (also known as drift models), we tested the role of two cultural selection models: coordination- and content-biased. We constructed a parametrized mixed probabilistic model of the spread of communicative variants in four 8-person laboratory micro-societies engaged in a simple communication game. We found that selectionist models, working in combination, explain the majority of the empirical data. The best-fitting parameter setting includes an egocentric bias and a content bias, suggesting that participants retained their own previously used communicative variants unless they encountered a superior (content-biased) variant, in which case it was adopted. This novel pattern of results suggests that (i) a theory of the cultural evolution of human communication systems must integrate selectionist models and (ii) human communication systems are functionally adaptive complex systems. PMID:24966310

Tamariz, Monica; Ellison, T Mark; Barr, Dale J; Fay, Nicolas

2014-08-01

345

A multipinhole small animal SPECT system with submillimeter spatial resolution  

SciTech Connect

Single photon emission computed tomography (SPECT) is an important technology for molecular imaging studies of small animals. In this arena, there is an increasing demand for high performance imaging systems that offer improved spatial resolution and detection efficiency. We have designed a multipinhole small animal imaging system based on position sensitive avalanche photodiode (PSAPD) detectors with the goal of submillimeter spatial resolution and high detection efficiency, which will allow us to minimize the radiation dose to the animal and to shorten the time needed for the imaging study. Our design will use 8x24 mm{sup 2} PSAPD detector modules coupled to thallium-doped cesium iodide [CsI(Tl)] scintillators, which can achieve an intrinsic spatial resolution of 0.5 mm at 140 keV. These detectors will be arranged in rings of 24 modules each; the animal is positioned in the center of the 9 stationary detector rings which capture projection data from the animal with a cylindrical tungsten multipinhole collimator. The animal is supported on a bed which can be rocked about the central axis to increase angular sampling of the object. In contrast to conventional SPECT pinhole systems, in our design each pinhole views only a portion of the object. However, the ensemble of projection data from all of the multipinhole detectors provide angular sampling that is sufficient to reconstruct tomographic data from the object. The performance of this multipinhole PSAPD imaging system was simulated using a ray tracing program that models the appropriate point spread functions and then was compared against the performance of a dual-headed pinhole SPECT system. The detection efficiency of both systems was simulated and projection data of a hot rod phantom were generated and reconstructed to assess spatial resolution. Appropriate Poisson noise was added to the data to simulate an acquisition time of 15 min and an activity of 18.5 MBq distributed in the phantom. Both sets of data were reconstructed with an ML-EM reconstruction algorithm. In addition, the imaging performance of both systems was evaluated with a uniformity phantom and a realistic digital mouse phantom. Simulations show that our proposed system produces a spatial resolution of 0.8 mm and an average detection efficiency of 630 cps/MBq. In contrast, simulations of the dual-headed pinhole SPECT system produce a spatial resolution of 1.1 mm and an average detection efficiency of 53 cps/MBq. These results suggest that our novel design will achieve high spatial resolution and will improve the detection efficiency by more than an order of magnitude compared to a dual-headed pinhole SPECT system. We expect that this system can perform SPECT with submillimeter spatial resolution, high throughput, and low radiation dose suitable for in vivo imaging of small animals.

Funk, Tobias; Despres, Philippe; Barber, William C.; Shah, Kanai S.; Hasegawa, Bruce H. [Department of Radiology, University of California, San Francisco, California 94107 (United States); Radiation Monitoring Devices, Inc., Watertown, Massachusetts 02472 (United States); Department of Radiology, University of California, San Francisco, California 94107, Joint Bioengineering Graduate Group, University of California, San Francisco and Berkeley, California 94107 and Department of Nuclear Engineering, University of California, Berkeley, Berkeley, California (United States)

2006-05-15

346

Research of a portable atmospheric laser communication system  

NASA Astrophysics Data System (ADS)

A kind of portable atmosphere laser communication system based on fiber technology is designed by using Ethernet transceiver terminal and video-audio transceiver terminal with diode laser module and PIN diode, while a flexible connection is built between the terminal and the optical antenna connected by laser fiber. The application of EDFA technology, which realizes the amplification of the power of the 1550nm laser diode module, brings forth a more stable structure and easier deployment and testing in wild environment, and the communication distance can reach 2 kilometers with a transmission bandwidth of 100 MBit/s. Prototype experiments prove the good communication performance of this system.

Zeng, Wen-feng; Li, Dong; Li, Shen-peng; Tan, Wei; Yi, Zhigang

2013-08-01

347

Workload characterization for the space station data communications system  

NASA Technical Reports Server (NTRS)

NASA plans to launch a permanent manned space station in the early 1990's. The station will be used to support a wide variety of activities involving Earth and space observation, satellite maintenance, scientific experimentation, and commercial manufacturing. The control and monitoring of many of these activities will require extensive computer and communications system support. In order to identify an appropriate computer and communication system for supporting the space station, an attempt to characterize the space station's data communications subsystem workload is currently underway. Some of the special aspects of the workload characterization problem are discussed in connection with the space station, and some possible approaches are presented.

Sevcik, K. C.

1986-01-01

348

Bioluminescent system for dynamic imaging of cell and animal behavior  

SciTech Connect

Highlights: Black-Right-Pointing-Pointer We combined a yellow variant of GFP and firefly luciferase to make ffLuc-cp156. Black-Right-Pointing-Pointer ffLuc-cp156 showed improved photon yield in cultured cells and transgenic mice. Black-Right-Pointing-Pointer ffLuc-cp156 enabled video-rate bioluminescence imaging of freely-moving animals. Black-Right-Pointing-Pointer ffLuc-cp156 mice enabled tracking real-time drug delivery in conscious animals. -- Abstract: The current utility of bioluminescence imaging is constrained by a low photon yield that limits temporal sensitivity. Here, we describe an imaging method that uses a chemiluminescent/fluorescent protein, ffLuc-cp156, which consists of a yellow variant of Aequorea GFP and firefly luciferase. We report an improvement in photon yield by over three orders of magnitude over current bioluminescent systems. We imaged cellular movement at high resolution including neuronal growth cones and microglial cell protrusions. Transgenic ffLuc-cp156 mice enabled video-rate bioluminescence imaging of freely moving animals, which may provide a reliable assay for drug distribution in behaving animals for pre-clinical studies.

Hara-Miyauchi, Chikako [Department of Physiology, Keio University School of Medicine, Tokyo 160-8582 (Japan) [Department of Physiology, Keio University School of Medicine, Tokyo 160-8582 (Japan); Laboratory for Cell Function Dynamics, Brain Science Institute, RIKEN, Saitama 351-0198 (Japan); Department of Biophysics and Biochemistry, Graduate School of Health Care Sciences, Tokyo Medical and Dental University, Tokyo 113-8510 (Japan); Tsuji, Osahiko [Department of Physiology, Keio University School of Medicine, Tokyo 160-8582 (Japan) [Department of Physiology, Keio University School of Medicine, Tokyo 160-8582 (Japan); Department of Orthopedic Surgery, Keio University School of Medicine, Tokyo 160-8582 (Japan); Hanyu, Aki [Division of Biochemistry, The Cancer Institute of the Japanese Foundation for Cancer Research, Tokyo 135-8550 (Japan)] [Division of Biochemistry, The Cancer Institute of the Japanese Foundation for Cancer Research, Tokyo 135-8550 (Japan); Okada, Seiji [Department of Advanced Medical Initiatives, Faculty of Medical Sciences, Kyushu University, Fukuoka 812-8582 (Japan)] [Department of Advanced Medical Initiatives, Faculty of Medical Sciences, Kyushu University, Fukuoka 812-8582 (Japan); Yasuda, Akimasa [Department of Physiology, Keio University School of Medicine, Tokyo 160-8582 (Japan) [Department of Physiology, Keio University School of Medicine, Tokyo 160-8582 (Japan); Department of Orthopedic Surgery, Keio University School of Medicine, Tokyo 160-8582 (Japan); Fukano, Takashi [Laboratory for Cell Function Dynamics, Brain Science Institute, RIKEN, Saitama 351-0198 (Japan)] [Laboratory for Cell Function Dynamics, Brain Science Institute, RIKEN, Saitama 351-0198 (Japan); Akazawa, Chihiro [Department of Biophysics and Biochemistry, Graduate School of Health Care Sciences, Tokyo Medical and Dental University, Tokyo 113-8510 (Japan)] [Department of Biophysics and Biochemistry, Graduate School of Health Care Sciences, Tokyo Medical and Dental University, Tokyo 113-8510 (Japan); Nakamura, Masaya [Department of Orthopedic Surgery, Keio University School of Medicine, Tokyo 160-8582 (Japan)] [Department of Orthopedic Surgery, Keio University School of Medicine, Tokyo 160-8582 (Japan); Imamura, Takeshi [Department of Molecular Medicine for Pathogenesis, Ehime University Graduate School of Medicine, Toon, Ehime 791-0295 (Japan) [Department of Molecular Medicine for Pathogenesis, Ehime University Graduate School of Medicine, Toon, Ehime 791-0295 (Japan); Core Research for Evolutional Science and Technology, The Japan Science and Technology Corporation, Tokyo 135-8550 (Japan); Matsuzaki, Yumi [Department of Physiology, Keio University School of Medicine, Tokyo 160-8582 (Japan)] [Department of Physiology, Keio University School of Medicine, Tokyo 160-8582 (Japan); Okano, Hirotaka James, E-mail: hjokano@jikei.ac.jp [Department of Physiology, Keio University School of Medicine, Tokyo 160-8582 (Japan); Division of Regenerative Medicine Jikei University School of Medicine, Tokyo 150-8461 (Japan); and others

2012-03-09

349

Nonlinear filter based decision feedback equalizer for optical communication systems.  

PubMed

Nonlinear impairments in optical communication system have become a major concern of optical engineers. In this paper, we demonstrate that utilizing a nonlinear filter based Decision Feedback Equalizer (DFE) with error detection capability can deliver a better performance compared with the conventional linear filter based DFE. The proposed algorithms are tested in simulation using a coherent 100 Gb/sec 16-QAM optical communication system in a legacy optical network setting. PMID:24718240

Han, Xiaoqi; Cheng, Chi-Hao

2014-04-01

350

Validation of the communications link analysis and simulation system (CLASS)  

NASA Technical Reports Server (NTRS)

CLASS (Communication Link Analysis and Simulation System) is a software package developed for NASA to predict the communication and tracking performance of the Tracking and Data Relay Satellite System (TDRSS) services. The methods used to verify CLASS are described. The usefulness of a software tool such as CLASS depends strongly on the reliability and accuracy of the results it produces. For this reason, considerable attention was paid to validation throughout the CLASS development.

Braun, W. R.; Mckenzie, T. M.

1985-01-01

351

Markov-jump-system-based secure chaotic communication  

Microsoft Academic Search

In this paper, a new Markov-jump-system (MJS)-based secure chaotic communication technique is proposed. An MJS evolves by switching from one state evolution model to another according to a finite state Markov chain. The transmitter in the proposed communication system is an MJS consisting of multiple transmission maps, that is, the transmitter switches from one chaotic map to another during the

Thuraiappah Sathyan; Thiagaligam Kirubarajan

2006-01-01

352

Assessment of communication system susceptibility to the PAVE PAWS radar  

NASA Astrophysics Data System (ADS)

This paper summarizes the results of a program directed to an assessment of the potential for interference to Georgia Power Company communications systems from the PAVE PAWS radar at Robins Air Force Base, GA. Susceptibility data were recorded on selected UHF and microwave receivers and compared to predicted PAVE PAWS field strength levels to identify potential interference problems. Several potential problems were identified which must be addressed to preclude PAVE PAWS related interference effects on communication system performance.

Donaldson, Ernest E., Jr.; Burdett, Robert P., Jr.

353

Communication architecture tuners: a methodology for the design of high-performance communication architectures for system-on-chips  

Microsoft Academic Search

In this paper, we present a general methodology for the design of custom system-on-chip communication architectures. Our technique is based on the addition of a layer of circuitry, called the Communica- tion Architecture Tuner (CAT), around any existing communication architecture topology. The added layer enhances the ability of the system to adapt to changing communication needs of its constituent components.

Kanishka Lahiri; Anand Raghunathan; Ganesh Lakshminarayana; Sujit Dey

2000-01-01

354

Communications for a picture archiving communications system with a parallel operating image data base.  

PubMed

In cooperation with BAZIS (Support Group Hospital Information Systems at Leiden, The Netherlands), we started the design of a Picture Archiving and Communications System (PACS) a few years ago that contains a centralized image data base. By means of system modeling and measuring some performance parameters, we have discovered that such a system cannot provide the required response times. This is mainly because of equipment communications interfaces that are not fast enough and have a throughput that does not generally exceed 16 Mbits/second. By providing a parallel operating image buffer system, the problems related to the limited speed of the communication interfaces can be overcome. Moreover, by splitting the network into a number of subnets connected to each other by means of "bridges," the communications load can be locally reduced, improving in this manner the response times. Our PACS contains a supervisor and one relational data base that relates patient data with image locations. A significant part of the report is concerned with the design of the high speed American College of Radiology-National Electronic Manufacturing Association transmission control protocol/internet protocol (ACR-NEMA TCP/IP) communications interface. The use of such an interface eliminates the need for a Network Interface Unit, reducing in this manner communication delays and complexity. We have developed and have in operation for experimental purposes a small-scale PACS, consisting of a number of workstations, a relational data base and image buffers, all connected to a network that uses the ACR-NEMA TCP/IP protocols. This experimental PACS is used to provide input data to a PACS performance model, to validate this model, and to investigate alternative system configurations. PMID:8439584

Reijns, G L; Kayser, A

1993-02-01

355

Estimation of the demand for public services communications. [market research and economic analysis for a communications satellite system  

NASA Technical Reports Server (NTRS)

Market analyses and economic studies are presented to support NASA planning for a communications satellite system to provide public services in health, education, mobile communications, data transfer, and teleconferencing.

1976-01-01

356

Study and design of laser communications system for space shuttle  

NASA Technical Reports Server (NTRS)

The design, development and operation are described of the laser communications system developed for potential space shuttle application. A brief study was conducted to identify the need, if any, for narrow bandwidth space-to-space communication on the shuttle vehicles. None have been specifically identified that could not be accommodated with existing equipments. The key technical features developed in this hardware are the conically scanned tracker for optimized track while communicating with a single detector, and the utilization of a common optical carrier frequency for both transmission and detection. This latter feature permits a multiple access capability so that several transceivers can communicate with one another. The conically scanned tracker technique allows the received signal energy to be efficiently divided between the tracking and communications functions within a common detector.

1973-01-01

357

Synthesis of system-level communication by an allocation-based approach  

Microsoft Academic Search

Abstract: Communication synthesis aims to transform a system with processes that communicate via high level primitives through channels into interconnected processes that communicate via signals and share communication control. We present a new algorithm that performs binding\\/allocation of communication units. This algorithm makes use of a cost function to evaluate different allocation alternatives. The proposed communication synthesis approach deals with

Jean-Marc Daveau; Tarek Ben Ismail; Ahmed Amine Jerraya

1995-01-01

358

An all digital low data rate communication system  

NASA Technical Reports Server (NTRS)

The advent of digital hardwares has made it feasible to implement many communication system components digitally. With the exception of frequency down conversion, the proposed low data rate communication system uses digital hardwares completely. Although the system is designed primarily for deep space communications with large frequency uncertainty and low signal-to-noise ratio, it is also suitable for other low data rate applications with time-shared operation among a number of channels. Emphasis is placed on the fast Fourier transform receiver and the automatic frequency control via digital filtering. The speed available from the digital system allows sophisticated signal processing to reduce frequency uncertainty and to increase the signal-to-noise ratio. The practical limitations of the system such as the finite register length are examined. It is concluded that the proposed all-digital system is not only technically feasible but also has potential cost reduction over the existing receiving systems.

Chen, C.; Fan, M.

1973-01-01

359

Integrated communication/environmental controller system for the physically disabled.  

PubMed

A wireless integrated communication/environmental controller system (ICECS) is described, which offers total communication as well as environmental control for the disabled person. The system is flexible and simple enough to be used from the wheelchair by patients with spinal cord injuries. The system has three parts: the mobile unit, the base unit, and a set of remote-control receiver modules. The mobile unit and the base unit are linked together by radio, while the base unit and the remote receiver modules communicate over a power line carrier. The telephone mode allows telephone calls to be placed and received. Different electrical devices are controlled by the environmental control mode. The intercom mode permits two-way communication with an attendant or the nursing station. The modes can be switched simply by pressing a button on the mobile unit. Sixteen soft-touch switches arranged in a 4 X 4 matrix allow operation by hand or mouthstick. PMID:2950838

Fatehi, M T; Balmaseda, M T; Koozekanani, S H

1987-03-01

360

DOE Integrated Security System (DISS) preliminary communication security analysis  

SciTech Connect

The purpose of this analysis is to document a technical approach to improve DOE Integrated Security System (DISS) dial-up communications security and the requirements to address them. This document is not intended as a comprehensive analysis of the security aspects of the DISS computer system but rather as an analysis of the dial-up communications security as it pertains to the use of the DISS database in the new DOE Automated Visitors Access Control System (DAVACS) procedures. Current access controls into the DISS will be discussed with emphasis on the DAVACS procedures. Recommendations will be provided for increasing the dial-up communications security into DISS as it relates to the automated visit procedures. Finally a design for an encrypted dial-up communication link to DISS will be given.

Sweeney, D.J.

1993-10-01

361

A systems engineering initiative for NASA's space communications  

NASA Technical Reports Server (NTRS)

In addition to but separate from the Red and Blue Teams commissioned by the NASA Administrator, NASA's Associate Administrator for Space Communications commissioned a Blue Team to review the Office of Space Communications (Code O) Core Program and determine how the program could be conducted faster, better, and cheaper, without compromising safety. Since there was no corresponding Red Team for the Code O Blue Team, the Blue Team assumed a Red Team independent attitude and challenged the status quo. The Blue Team process and results are summarized. The Associate Administrator for Space Communications subsequently convened a special management session to discuss the significance and implications of the Blue Team's report and to lay the groundwork and teamwork for the next steps, including the transition from engineering systems to systems engineering. The methodology and progress toward realizing the Code O Family vision and accomplishing the systems engineering initiative for NASA's space communications are presented.

Hornstein, Rhoda S.; Hei, Donald J., Jr.; Kelly, Angelita C.; Lightfoot, Patricia C.; Bell, Holland T.; Cureton-Snead, Izeller E.; Hurd, William J.; Scales, Charles H.

1993-01-01

362

Field experiment on digital maritime satellite communication systems  

NASA Astrophysics Data System (ADS)

The system configuration and results are presented for a field experiment on digital maritime satellite communication systems carried out in December 1986, using the INMARSAT Indian Ocean satellite (INTELSAT-V with maritime communication subsystem). The digital communication subsystem used for the experiment consists of a 16-kb/s APC (adaptive predictive coding) voice codec and a rate-3/4 FEC (forward-error correcting) codec using Viterbi decoding for punctured code to utilize the satellite power and bandwidth as efficiently as possible. For the ship earth station, a high-gain antenna with G/T (gain to temperature) of -4 dBK and a low-gain antenna with G/T of -10 dBK were used. The effectiveness of the digital ship earth station system was verified under the actual maritime satellite communication environment with multipath fading.

Yasuda, Yutaka; Ohashi, Masayoshi; Sugaya, Fumiaki; Hirata, Yasuo; Okinaka, Hideo

363

Availability Improvement for WLAN-Based Train-Ground Communication Systems in Communication-Based Train Control (CBTC)  

Microsoft Academic Search

Train-ground communication technology is one of the key technologies for communication-based train control (CBTC), which is an automated train control system for railways that ensures safe operation of rail vehicles using data communications. In CBTC systems, less service availability could cause train derailment, collision or even catastrophic loss of lives or assets. Therefore, the availability of train-ground communication should be

Li Zhu; F. Richard Yu; Bing Ning

2010-01-01

364

Methods for operating parallel computing systems employing sequenced communications  

DOEpatents

A parallel computing system and method are disclosed having improved performance where a program is concurrently run on a plurality of nodes for reducing total processing time, each node having a processor, a memory, and a predetermined number of communication channels connected to the node and independently connected directly to other nodes. The present invention improves performance of the parallel computing system by providing a system which can provide efficient communication between the processors and between the system and input and output devices. A method is also disclosed which can locate defective nodes with the computing system. 15 figs.

Benner, R.E.; Gustafson, J.L.; Montry, G.R.

1999-08-10

365

Programmable modular joint tactical radio in a communications system environment  

NASA Astrophysics Data System (ADS)

The Joint Tactical Radio System (JTRS) is a software programmable and modular communications system that will be interoperable with legacy waveforms. It will also be capable of satisfying new communication system requirements for a multitude of military and civilian land, air, and maritime platforms. A Systems Reference Model has been developed to guide a systems architecture design that will use families of common hardware and software configurations to support requirements of different users. The JTRS is a cost-effective approach that allows users to dynamically change capability by reinitializing application software.

Dyson, Richard M.; Newman, Alfred V.; Noll, Bruce T.; Russell, Victor C.

1998-08-01

366

All-optical animation projection system with rotating fieldstone.  

PubMed

A simple and compact rewritable holographic memory system using a fieldstone of Ulexite is proposed. The role of the fieldstone is to impose random patterns on the reference beam to record plural images with the random-reference multiplexing scheme. The operations for writing and reading holograms are carried out by simply rotating the fieldstone in one direction. One of the features of this approach is found in a way to generate random patterns without computer drawings. The experimental study confirms that our system enables the smooth readout of the stored images one after another so that the series of reproduced images are projected as an animation. PMID:19547042

Ishii, Yuko; Takayama, Yoshihisa; Kodate, Kashiko

2007-06-11

367

All-optical animation projection system with rotating fieldstone  

NASA Astrophysics Data System (ADS)

A simple and compact rewritable holographic memory system using a fieldstone of Ulexite is proposed. The role of the fieldstone is to impose random patterns on the reference beam to record plural images with the random-reference multiplexing scheme. The operations for writing and reading holograms are carried out by simply rotating the fieldstone in one direction. One of the features of this approach is found in a way to generate random patterns without computer drawings. The experimental study confirms that our system enables the smooth readout of the stored images one after another so that the series of reproduced images are projected as an animation.

Ishii, Yuko; Takayama, Yoshihisa; Kodate, Kashiko

2007-06-01

368

Bioluminescent system for dynamic imaging of cell and animal behavior.  

PubMed

The current utility of bioluminescence imaging is constrained by a low photon yield that limits temporal sensitivity. Here, we describe an imaging method that uses a chemiluminescent/fluorescent protein, ffLuc-cp156, which consists of a yellow variant of Aequorea GFP and firefly luciferase. We report an improvement in photon yield by over three orders of magnitude over current bioluminescent systems. We imaged cellular movement at high resolution including neuronal growth cones and microglial cell protrusions. Transgenic ffLuc-cp156 mice enabled video-rate bioluminescence imaging of freely moving animals, which may provide a reliable assay for drug distribution in behaving animals for pre-clinical studies. PMID:22333570

Hara-Miyauchi, Chikako; Tsuji, Osahiko; Hanyu, Aki; Okada, Seiji; Yasuda, Akimasa; Fukano, Takashi; Akazawa, Chihiro; Nakamura, Masaya; Imamura, Takeshi; Matsuzaki, Yumi; Okano, Hirotaka James; Miyawaki, Atsushi; Okano, Hideyuki

2012-03-01

369

Integrated source and channel encoded digital communication system design study  

NASA Technical Reports Server (NTRS)

The particular Ku-band carrier, PN despreading, and symbol synchronization strategies, which were selected for implementation in the Ku-band transponder aboard the orbiter, were assessed and evaluated from a systems performance viewpoint, verifying that system specifications were met. A study was performed of the design and implementation of tracking techniques which are suitable for incorporation into the Orbiter Ku-band communication system. Emphasis was placed on maximizing tracking accuracy and communication system flexibility while minimizing cost, weight, and system complexity of Orbiter and ground systems hardware. The payload communication study assessed the design and performance of the forward link and return link bent-pipe relay modes for attached and detached payloads. As part of this study, a design for a forward link bent-pipe was proposed which employs a residual carrier but which is tracked by the existing Costas loop.

Alem, W. K.; Huth, G. K.; Simon, M. K.

1978-01-01

370

Effect of latrogenic trauma on the bone scintigram: an animal study. Concise communication. [Rabbits  

SciTech Connect

An animal study was performed to assess the effect on the Tc-99m phosphate bone scintigram of injury by needle aspiration or drill hole to metaphyseal and diaphyseal areas in immature and mature bones. Results showed that in 12 immature rabbits such trauma to metaphyseal regions had no effect on the bone image. Similar metaphyseal trauma in two mature dogs showed definite abnormalities on the bone image, but in one mature rabbit, no abnormality could be identified by scintigram. Diaphyseal trauma always gave a definitely abnormal bone image. Extrapolation of these results to humans should be cautious, but it suggests that needling or drilling in metaphyseal regions in neonates or young children probably does not affect later bone images.

Alazraki, N.; Moitoza, J.; Heaphy, J.; Taylor, A. Jr.

1984-09-01

371

Communicating emotions in online chat using physiological sensors and animated text  

Microsoft Academic Search

We present a chat system that uses animateddynamic text associated with emotional information to show the affective state of the user. The system obtains the affective state of a chat user from a physiological sensor attached to the user's body. This paper describes preliminary experiments and provides examples of possible applications of our chat system. Observations from informal experiments comparing

Hua Wang; Helmut Prendinger; Takeo Igarashi

2004-01-01

372

26 CFR 49.4253-9 - Exemption for certain interior communication systems.  

Code of Federal Regulations, 2013 CFR

... Exemption for certain interior communication systems. 49.4253-9 Section...FACILITIES AND SERVICES EXCISE TAXES Communications § 49.4253-9 Exemption for certain interior communication systems. (a) In...

2013-04-01

373

Support systems: older adults with neurogenic communication disorders.  

PubMed

As the population of older adults increases, there is a corresponding increase in the number of individuals with communication disorders resulting from brain damage. The purpose of this article was to describe the effects of aphasia and dementia on language and communication, and to suggest support systems for improving communication and maximizing residual language abilities. For both these disorders, we address the psychosocial environment, the roles of professionals and caregivers, individual versus group therapy, and support groups. Finally, we report on 2 specific support groups, one for aphasia and one for Alzheimer's dementia, with which the authors have been involved for many years. PMID:15495748

Goldfarb, Robert; Pietro, Mary Jo Santo

2004-01-01

374

The Flexible Bus Systems Using Zigbee as a Communication Medium  

Microsoft Academic Search

This paper describes a research on The Flexible Bus Systems (FBS) using Zigbee as a communication medium. The Flexible Bus System is a demand responsive transit (DRT) but it is more efficient and convenient in a sense that it entertains passenger's demands and gives bus locations in real time. The real time synchronization of The Flexible Bus System makes it

Razi Iqbal; Kenichi Yukimatsu; Tatsuya Ichikawa

2011-01-01

375

Secure Communication with Chaotic Systems of Difference Equations  

Microsoft Academic Search

The paper presents chaotic systems of difference equations that can effectively encrypt information. Two classes of systems are presented: The first one (Class 1) is optimized for secure communications over reliable channels, while the second (Class 2) tolerates transmission noise at the expense of reduced parameter space size. The nonlinearity of these systems is achieved by designing proper piecewise linear

Stergios Papadimitriou; Anastasios Bezerianos; Tassos Bountis

1997-01-01

376

Performance analysis of communication network for the CBTC system  

Microsoft Academic Search

Communication based train control (CBTC) system is a safety critical system, and several factors in the system demand for new design and implementation solutions. Combining some software or hardware errors, a dual redundant network is proposed. Moreover, framework and working mode of the network are introduced. The paper evaluates the reliability in theory. A simulation is realized to test how

Yufei Xie; Tao Tang

2009-01-01

377

Towards a Systematic Test for Embedded Automotive Communication Systems  

Microsoft Academic Search

The introduction of computer-controlled intelligent safety and comfort features has turned cars into complex distri- buted computing systems. In such a system the proper operation of the communication backbone as well as the proper interaction of components from different vendors must be ensured for all configurations and operating conditions. This system-level test goes far beyond the (isolated) test of single

Eric Armengaud; Andreas Steininger; Martin Horauer

2008-01-01

378

The research on tactical communication network simulative training system  

Microsoft Academic Search

In order to meet the educating and training requirements of tactical communication network (TCN), one advanced means is to develop its simulative training system. Firstly, the general framework of TCN simulative training system was designed, which included the system constitution, software structure and application manner. Secondly, a single federation and multi federation architecture were proposed, which solved the distributed interactive

Jian-jun Shen; Jing-jing Li; Xiao-hu Yu

2010-01-01

379

Remotely controlled communication and control system for limited mobility individuals  

Microsoft Academic Search

Design improvements to a remotely controlled system for patients with limited mobility are described. This system provides communication and control of the room environment with mouse control that can be adapted to the functional need of the user. Analysis is provided on the selection and integration of components within the system as well as an overview of the simulated access

Matthew Goldman; Ettore Cervo; Alexander Melle; Bryan Wilson; Seyitriza Tigrek; Frank Agyei-Ntim; Kimberly E. Newman; Frank Barnes; Michael Blei

2011-01-01

380

Secure communication via one-dimensional chaotic inverse systems  

Microsoft Academic Search

in chaotic secure communications, even one-dimensional discrete chaotic systems are able to provide a high level of security. This paper demonstrates that in the way of chaotic inverse system approach, a class of piecewise linear chaotic systems can provide better encryption performances than most other chaotic cryptosystems, such as uniform distribution, ?-like correlation function, sensitivity to parameter mismatch, and high

Hong Zhou; Xie-Tang Ling; Juii Yu

1997-01-01

381

Building reliable, high-performance communication systems from components  

Microsoft Academic Search

Although building systems from components has attractions, this approach also has problems. Can we be sure that a certain configuration of components is correct? Can it perform as well as a monolithic system? Our paper answers these questions for the Ensemble communication architecture by showing how, with help of the Nuprl formal system, configurations may be checked against specifications, and

Xiaoming Liu; Christoph Kreitz; Robbert van Renesse; Jason Hickey; Mark Hayden; Kenneth P. Birman; Robert L. Constable

1999-01-01

382

A Dynamic System for Personal Communications: The Opportunistic Chat  

Microsoft Academic Search

Most of currently available inter-personal instant messaging systems are client-server based. Users of such systems need to be connected to some centralized entity which goal is to supply them with information needed to make the communication possible, such as the list of connected users, their status, and the address of their devices. Our proposed system for an \\

Salvatore Sorce; Francesco Cinquegrani; Salvatore Maria Anzalone; Dario Caccìa; Antonio Gentile; Alessandro Genco

2007-01-01

383

Simulation system architecture design for generic communications link  

NASA Technical Reports Server (NTRS)

This paper addresses a computer simulation system architecture design for generic digital communications systems. It addresses the issues of an overall system architecture in order to achieve a user-friendly, efficient, and yet easily implementable simulation system. The system block diagram and its individual functional components are described in detail. Software implementation is discussed with the VAX/VMS operating system used as a target environment.

Tsang, Chit-Sang; Ratliff, Jim

1986-01-01

384

Simulation system architecture design for generic communications link  

NASA Astrophysics Data System (ADS)

This paper addresses a computer simulation system architecture design for generic digital communications systems. It addresses the issues of an overall system architecture in order to achieve a user-friendly, efficient, and yet easily implementable simulation system. The system block diagram and its individual functional components are described in detail. Software implementation is discussed with the VAX/VMS operating system used as a target environment.

Tsang, Chit-Sang; Ratliff, Jim

385

Chaos-based communication systems in non-ideal channels  

NASA Astrophysics Data System (ADS)

Recently, many chaos-based communication systems have been proposed. They can present the many interesting properties of spread spectrum modulations. Besides, they can represent a low-cost increase in security. However, their major drawback is to have a Bit Error Rate (BER) general performance worse than their conventional counterparts. In this paper, we review some innovative techniques that can be used to make chaos-based communication systems attain lower levels of BER in non-ideal environments. In particular, we succinctly describe techniques to counter the effects of finite bandwidth, additive noise and delay in the communication channel. Although much research is necessary for chaos-based communication competing with conventional techniques, the presented results are auspicious.

Eisencraft, M.; Fanganiello, R. D.; Grzybowski, J. M. V.; Soriano, D. C.; Attux, R.; Batista, A. M.; Macau, E. E. N.; Monteiro, L. H. A.; Romano, J. M. T.; Suyama, R.; Yoneyama, T.

2012-12-01

386

Random Matrix Methods for Design of Multiuser Communication Systems  

NASA Astrophysics Data System (ADS)

A short review on multiuser communication systems is given. System design for iterative multiuser decoding is improved by means of large system results from statistical physics and random matrix theory. With the application of multiuser detection for wireless communications in mind, it is shown how a system of linear equations with random coefficients can be solved efficiently exploiting the asymptotic convergence of its eigenvalue spectrum. In addition, the conditional convergence of the diagonal elements of a power of a random matrix drawn from a Marchenko--Pastur ensemble is established.

Mueller, R. R.

2005-09-01

387

Communication.  

ERIC Educational Resources Information Center

This theme issue on communication includes annotated listings of Web sites, CD-ROM and computer software, videos, books, and professional resources that deal with various methods of communication. Sidebars discuss mythology, photojournalism, sharing ideas on the Web, and songs of protest. Suggestions for class activities are also included. (LRW)

Online-Offline, 1998

1998-01-01

388

Use of 2.4 GHz frequency band for Communications Based Train Control data communications systems  

Microsoft Academic Search

The increasing deployment of CBTC by public transit agencies that use a data communications systems based in the 2.4 GHz ISM band has raised the concern of RF interference between CBTC equipped trains and the variety of new and existing users of this band. The vast number of RF devices that currently operate in this band (like microwave ovens, cordless

M. Fitzmaurice

2006-01-01

389

The effects of hands-free communication device systems: communication changes in hospital organizations  

Microsoft Academic Search

Objective To analyze the effects that hands-free communication device (HCD) systems have on healthcare organizations from multiple user perspectives. Design This exploratory qualitative study recruited 26 subjects from multiple departments in two research sites located in Portland, Oregon: an academic medical center and a community hospital. Interview and observation data were gathered January through March, 2007. Measurements Data were analyzed

Joshua E Richardson; Joan S Ash

2010-01-01

390

A dual micro-CT system for small animal imaging  

PubMed Central

Micro-CT is a non-invasive imaging modality usually used to assess morphology in small animals. In our previous work, we have demonstrated that functional micro-CT imaging is also possible. This paper describes a dual micro-CT system with two fixed x-ray/detectors developed to address such challenging tasks as cardiac or perfusion studies in small animals. A two-tube/detector system ensures simultaneous acquisition of two projections, thus reducing scanning time and the number of contrast injections in perfusion studies by a factor of two. The system is integrated with software developed in-house for cardio-respiratory monitoring and gating. The sampling geometry was optimized for 88 microns in such a way that the geometric blur of the focal spot matches the Nyquist sample at the detector. A geometric calibration procedure allows one to combine projection data from the two chains into a single reconstructed volume. Image quality was measured in terms of spatial resolution, uniformity, noise, and linearity. The modulation transfer function (MTF) at 10% is 3.4 lp/mm for single detector reconstructions and 2.3 lp/mm for dual tube/detector reconstructions. We attribute this loss in spatial resolution to the compounding of slight errors in the separate single chain calibrations. The dual micro-CT system is currently used in studies for morphological and functional imaging of both rats and mice.

Badea, C.T.; Johnston, S.; Johnson, B.; Lin, M.; Hedlund, L.W.; Johnson, G. Allan

2011-01-01

391

A dual micro-CT system for small animal imaging  

NASA Astrophysics Data System (ADS)

Micro-CT is a non-invasive imaging modality usually used to assess morphology in small animals. In our previous work, we have demonstrated that functional micro-CT imaging is also possible. This paper describes a dual micro-CT system with two fixed x-ray/detectors developed to address such challenging tasks as cardiac or perfusion studies in small animals. A two-tube/detector system ensures simultaneous acquisition of two projections, thus reducing scanning time and the number of contrast injections in perfusion studies by a factor of two. The system is integrated with software developed in-house for cardio-respiratory monitoring and gating. The sampling geometry was optimized for 88 microns in such a way that the geometric blur of the focal spot matches the Nyquist sample at the detector. A geometric calibration procedure allows one to combine projection data from the two chains into a single reconstructed volume. Image quality was measured in terms of spatial resolution, uniformity, noise, and linearity. The modulation transfer function (MTF) at 10% is 3.4 lp/mm for single detector reconstructions and 2.3 lp/mm for dual tube/detector reconstructions. We attribute this loss in spatial resolution to the compounding of slight errors in the separate single chain calibrations. The dual micro-CT system is currently used in studies for morphological and functional imaging of both rats and mice.

Badea, C. T.; Johnston, S.; Johnson, B.; Lin, M.; Hedlund, L. W.; Johnson, G. Allan

2008-04-01

392

Satellite communications systems and technology. Volume 2: Site reports  

NASA Technical Reports Server (NTRS)

This is volume 2 of the final report of the NASA/NSF Panel on Satellite Communications Systems and Technology. It consists of the site reports from the panel's visits to satellite communications facilities and laboratories in Europe, Japan, and Russia. The Executive Summary of the panel's final report is published separately. Volume 1, also published separately, consists of the panel's analytical chapters. Information on ordering the Executive Summary and Volume 1 from the National Technical Information Service is included.

Edelson, Burton I. (editor); Pelton, Joseph N. (editor); Bostian, Charles W.; Brandon, William T.; Chan, Vincent W. S.; Hager, E. Paul; Helm, Neil R.; Jennings, Raymond D.; Kwan, Robert K.; Mahle, Christoph E.

1993-01-01

393

MLCD: Overview of NASA's Mars Laser Communications Demonstration System  

Microsoft Academic Search

NASA is presently overseeing a project to create the world's first free-space laser communications system that can be operated over a range much larger than the near-earth ranges that have been demonstrated to date. To be flown on the Mars Telecom Orbiter, planned for launch by NASA in 2009, it will demonstrate high-rate laser communications from Mars orbit to one

D. M. Boroson; A. Biswas; B. L. Edwards

394

MAC for dedicated short range communications in intelligent transport system  

Microsoft Academic Search

The need for critical improvements to the North American surface transportation infrastructure vis-a-vis alleviation of congestion while enhancing public safety has led to new intelligent transportation system (ITS) infrastructure based on vehicle-to-vehicle (v2v) wireless communications. The allocation of 75 MHz in the 5.9 GHz band for dedicated short-range communications (DSRC) may also enable future delivery of rich media content to

Jing Zhu; S. Roy

2003-01-01

395

Animal Bioacoustics  

NASA Astrophysics Data System (ADS)

Animals rely upon their acoustic and vibrational senses and abilities to detect the presence of both predators and prey and to communicate with members of the same species. This chapter surveys the physical bases of these abilities and their evolutionary optimization in insects, birds, and other land animals, and in a variety of aquatic animals other than cetaceans, which are treated in Chap. 20. While there are many individual variations, and some animals devote an immense fraction of their time and energy to acoustic communication, there are also many common features in their sound production and in the detection of sounds and vibrations. Excellent treatments of these matters from a biological viewpoint are given in several notable books [19.1,2] and collections of papers [19.3,4,5,6,7,8], together with other more specialized books to be mentioned in the following sections, but treatments from an acoustical viewpoint [19.9] are rare. The main difference between these two approaches is that biological books tend to concentrate on anatomical and physiological details and on behavioral outcomes, while acoustical books use simplified anatomical models and quantitative analysis to model whole-system behavior. This latter is the approach to be adopted here.

Fletcher, Neville

396

Guidebook for Selecting Cost-Effective Wireless Communication Technologies for Intelligent Transportation Systems  

Microsoft Academic Search

The advances of modern communication technologies have changed the way the roadway information is collected. Innovative surveillance systems powered by various communication technologies have been installed to support various transportation operations. The abundance of available communication technologies and multiple available communication system configurations presents overwhelming challenges for traffic engineers in selecting proper communication technologies for users of various traffic operation

Yi-Chang Chiu; Haitham Logman; Mo-Ning Chiu; Analsoni Sunkara; Carl Haas

397

Enterprise resource planning systems and communicative action  

Microsoft Academic Search

Enterprise resource planning (ERP) systems represent a quantum leap in integrated, entity-wide information systems. Managers are implementing these enterprise-wide systems in organizations of all sizes and types. Ironically, by implementing such all-encompassing and prespecified systems, organizational managers in effect lose control of the strategic and operational processes and models that frame and instantiate the enterprise's management information system and ultimately

Jesse F. Dillard; Kristi Yuthas

2006-01-01

398

Solar heating of integrated greenhouse-animal shelter systems  

SciTech Connect

An analytical procedure to determine the effectiveness of greenhouses as solar collectors was presented. This procedure was used to predict the effect of several construction parameters on solar radiation input to greenhouses. The orientation of the greenhouse was found to be the most effective construction parameter controlling solar radiation input to greenhouses. The effective albedo of the plant canopy was also found to be a significant factor. A new solar greenhouse design, suitable for high latitude regions was developed. The results showed that an internal solar collector could be incorporated as an integral part of the greenhouse design. The concept developed could be used as a free-standing greenhouse or in a combination with livestock building. The efficiency of the solar input was investigated for the conventional and the shed greenhouses, both as a free-standing unit and a greenhouse-animal shelter system, using computer simulation analyses. The results indicated that the efficiency of solar input is highly dependent on location; the effect of location on the shed type design is more profound. A typical case of a greenhouse-hog barn production system was investigated using computer simulation analyses. The results showed that such a food production system achieves a significant reduction in conventional fuel consumption due to both animal waste heat recovery and solar energy utilization.

Ben-Abdallah, N.

1983-01-01

399

Process chromatograph/continuous analyzer communications with distributed control systems  

SciTech Connect

A microprocessor-based system which interfaces multiple chromatographs and continuous analyzers directly to the communications network of a digital control system is described. The system provides an alternative to traditional analog signal links to the control system and to digital links to an associated host computer. Composition information is processed and relayed to the control system along with the validity messages for data security. Application examples of the use of analyzer data for catalytic reformer octane control and fractionation control are given.

Earle, W.; Hall, G.F.; Williams, R.A.; Villalobos, R.

1986-01-01

400

A New Remote-controlled Animal Robot Training System  

Microsoft Academic Search

This paper presents a new scatheless platform for training remote-controlled animal robot, which can be used to analyze the relations between electrical stimulation and animal behavior. It will not only provide a convenient platform and method to research the controllability of animal behavior and the possibility of training animal robots, but also open new possibilities for biomedical, artificial intelligence and

Yongling Wang; Kui Yuan; Jianfeng Li; Weiguo Song

2007-01-01

401

Short communication: renal tubular vacuolation in animals treated with polyethylene-glycol-conjugated proteins.  

PubMed

During toxicologic evaluation of a dimeric PEG-linked protein, tumor necrosis factor binding protein (TNF-bp), vacuolation of renal cortical tubular epithelium was seen in male and female Sprague-Dawley rats (200-300 g) given i.v. doses of 40, 20, or 10 mg/kg every other day for 3 months. Tubular lesions in rats treated with 20 or 40 mg/kg for 3 months were only partially reversible after a 2-month recovery period. Despite the presence of marked vacuolation, there were no changes in BUN, creatinine, urinalysis parameters, urinary NAG, urinary B2-microglobulin, or fractional sodium excretion. Single i.v. doses > or = 20 mg/kg TNF-bp caused similar but milder changes. However, equivalent doses of PEG alone or the non-PEG-linked TNF-bp did not cause light microscopic evidence of vacuolation. Treatment of rats with another PEG-linked protein of similar molecular weight resulted in similar changes. Immunostaining for TNF-bp revealed positivity in the apical cytoplasm of renal tubular epithelium within 1 h of i.v. dosing. Immunostaining of kidneys from chronically dosed rats indicated that protein was present in some vacuoles as long as dosing continued; however, kidneys from animals on a reversibility study had vacuoles but no immunostaining for TNF-bp. These results, along with a study that showed more severe lesions with PEG-linked proteins of lower molecular weight and minimal if any lesions with PEG-linked proteins > 70 kDa, suggest that TNF-bp is filtered through the glomerulus and that the protein with attached PEG is reabsorbed by the proximal tubules. Vacuolation may be a result of fluid distension of lysosomes due to the hygroscopic nature of PEG. These studies demonstrated that PEG-linked proteins have the capacity to induce renal tubular vacuolation at high doses. However, the change was not associated with alteration of clinical pathology or functional markers. PMID:9579027

Bendele, A; Seely, J; Richey, C; Sennello, G; Shopp, G

1998-04-01

402

Communications satellite systems operations with the space station, volume 2  

NASA Technical Reports Server (NTRS)

A financial model was developed which described quantitatively the economics of the space segment of communication satellite systems. The model describes the economics of the space system throughout the lifetime of the satellite. The expected state-of-the-art status of communications satellite systems and operations beginning service in 1995 were assessed and described. New or enhanced space-based activities and associated satellite system designs that have the potential to achieve future communications satellite operations in geostationary orbit with improved economic performance were postulated and defined. Three scenarios using combinations of space-based activities were analyzed: a spin stabilized satellite, a three axis satellite, and assembly at the Space Station and GEO servicing. Functional and technical requirements placed on the Space Station by the scenarios were detailed. Requirements on the satellite were also listed.

Price, K.; Dixon, J.; Weyandt, C.

1987-01-01

403

Communication system facilitates integrated patient-centred care.  

PubMed

At the Wellesley Hospital in Toronto, a unit designed to house patients awaiting placement developed a communication system to facilitate integrated patient-centred care. The system included a patient and family orientation brochure, an interdisciplinary kardex and an interdisciplinary patient goal sheet. Patient care improved under the new system, as staff was easily able to access current assessment data and establish and document integrated patient goals. Other outcomes included improved communication among team members, enhanced team member accountability, cohesiveness and satisfaction, and increased patient and family satisfaction. PMID:10144378

Escaf, M

1995-01-01

404

[Animals (Animalia) in system of organisms. 2. Phylogenetic understanding of animals].  

PubMed

The development of systematics in last decade has shown that typological classifications of five-six Kingdoms is not adequate for describing the diversity of organisms. Information from the sequences of small subunit rRNA is not sufficient to reconstruct the position of eukaryotes on the phylogenetic tree due to the effect of long branches. Totally new reconstruction of eukaryotic phylogeny was built upon the analysis of many new molecular markers. Evolution of eukaryotes had two mainstreams. One has been connected with diversification of ancestral biciliate forms (Bikonta). Sister-group of Bikonta (Unikonta) includes some originally uniciliate amoebae and moulds (Amoebozoa), and uniciliate eukaryotes with posterior cilium (Opisthokonta). The taxon Opisthokonta unites Fungi, Nuclearimorpha, Mesomycetozoa, Choanozoa and Metazoa. The latter three groups or only Metazoa are attributes to animals. The following differentiation of the groups used in systematic for the description of diversity of organisms is proposed. (1) Taxon is a group which is defined on the basis of ancestry: taxon includes all species descended from one ancestor. Taxon differs from logic classes of typology at an ontologic level. Taxon arises and exists, and its composition and occupied niches can constantly change; taxon can flourish or, on the contrary, fade up to full disappearance. Thus, the predicative characteristic of taxon, including characters which are considered significant, are not absolute. It is significant only at the moment of consideration. But characters (synapomorphies) are important as the practical tool for discerning taxa at given time period. Taxa unite species into unique classification. This understanding of taxon corresponds to monophyletic group sensu Willi Hennig. (2) Class of organisms is a group which is defined on the basis of characters: class includes all species having the given character. The class is only a logic object. Unlike taxa grouping species into classes may be through different and crossed classifications. Inside the given category of groups it is possible to distinguish: (2.1) Level of the organization (grade) described by the differences on the levels of organization: for example prokaryotic and eukaryotic levels of the organization. Eukaryotes can be divided into unicellular (Protoctista, Protista) and multicelluar (tissue-specific-Histonia) forms. (2.2) Types of the organization distinguishing groups of one level: for example, amoedoid type (Sarcodina), naked (Gymnamoebia), and testate (Testacea) amoebas. (2.3) Taxonomic groups as set-theoretical approximations of taxa. (2.4) Groups of the mixed nature. For example, Haeckel has recognized Protophyta and Protozoa describing the unicellular level of the organization inside plants and animals accordingly. Protozoa in Cavalier-Smith's system (2002, 2004) is also an example of groups of the mixed nature. PMID:16245570

Shatalkin, A I

2005-01-01

405

A Seamless Handoff Scheme for Train-Ground Communication Systems in CBTC  

Microsoft Academic Search

Communication-based train control (CBTC) system is an automated control system for railways that ensures the safe operation of rail vehicles using wireless data communications. The train-ground communication system is one of the key subsystem of CBTC. CBTC systems have stringent requirements for wireless communication availability and latency. In this paper, we propose a seamless handoff scheme based on stream control

Li Zhu; F. Richard Yu; Bing Ning

2010-01-01

406

Communication synthesis for distributed embedded systems  

Microsoft Academic Search

Designers of distributed embedded systems face many challenges in determining the appropriate tradeoffs to make when defining a system architecture or retargeting an existing design. Communica- tion synthesis, the automatic generation of the necessary software and hardware needed for system components to exchange data, is required to more effectively explore the design space and automate what are very error-prone tasks.

Ross B. Ortega; Gaetano Borriello

1998-01-01

407

A Low Cost Communication Sattelite Educational System.  

ERIC Educational Resources Information Center

The report discusses the potential of satellites for education and applies the principles of system engineering to studies of system implementation and cost effectiveness. The proposed system makes use of television and of a space vehicle, and excels in the modesty of its transmitter and receiver requirements on the ground and on the spacecraft.…

Dlugatch, Irving

408

A Simple Method for Reliability Evaluation of a Communication System  

Microsoft Academic Search

Very few techniques exist for reliability evaluation of communication systems where links as well as nodes have certain probability of failure. This correspondence describes a technique by which the reliability expression for such a system can be conveniently derived. It is also shown that using the concept of this correspondence, it is possible to extend all the existing reliability-evaluation algorithms

K. K. AGGARWAL; J. S. GUPTA; K. B. MISRA

1975-01-01

409

An asynchronous multiplex communication system for data collection  

Microsoft Academic Search

The paper describes and analyzes an asynchronous multiplex communication system which achieves a reduction in synchronization time by using asynchronous sampling reception of a digital burst signal with a short duty cycle. Transmit signal loss probability is considered and an optimum signal receiving system is derived by treating the bit decision process as a composite statistical hypothesis test problem. The

S. Tasaka; Y. Yasuda

1975-01-01

410

Present and future trends in military satellite communication systems  

Microsoft Academic Search

Recent years have seen a phenomenal growth in the field of satellite communications. Satcom systems offer many advantages for military applications which include wide area coverage, rapid deployment, flexible networking and long range service to moving platforms like ships, aircraft and vehicles. This paper gives an overview of the special features and future trends in military satcom systems. A brief

C. K. Chatterjee; Surendra Pal

1993-01-01

411

Automatic restart for communication based train control systems  

Microsoft Academic Search

Existing, fully automated, communication based train control (CBTC) system designs are facing a significant issue relative to system recovery due to a complete wayside automatic train protection (ATP) computer outage, (i.e. both primary and backup). This paper describes the problems related to CBTC automatic recovery and presents how the problem is handled with the Bombardier* CITYFLO* 450 and 650 automatic

A. Mirtchev

2005-01-01

412

A reduced complexity digital multicarrier demodulator for satellite communication systems  

Microsoft Academic Search

The design of a completely digital multicarrier demodulator (MCD) for application in advanced satellite communication systems is presented. The MCD represents a complete solution for a processing system interfacing FDMA and TDM links. Its design is in particular aimed at possible implementation by means of custom VLSI digital circuits. The proposed MCD has two parts: the demultiplexer and the coherent

E. del Re; R. Fantacci

1988-01-01

413

On the Power of Deterministic and Sequential Communicating P Systems  

Microsoft Academic Search

Abstract. We characterize the computational power of several restricted variants of communicating P systems. We show that 2-deterministic com- municating P systems with 2 membranes, working in either minimally or maximally parallel mode, are computationally universal. Considering the sequential mode, 2 membranes are shown to characterize the power of partially blind multicounter machines. Next, a characterization of the power of

Ludek Cienciala; Lucie Ciencialová; Pierluigi Frisco; Petr Sosík

2007-01-01

414

On the Power of Deterministic and Sequential Communicating P Systems  

Microsoft Academic Search

We characterize the computational power of several restricted variants of communicating P systems. We show that 2-deterministic com- municating P systems with 2 membranes, working in either minimally or maximally parallel mode, are computationally universal. Considering the sequential mode, 2 membranes are shown to characterize the power of partially blind multicounter machines. Next, a characterization of the power of 1-deterministic

Ludek Cienciala; Lucie Ciencialova; Pierluigi Frisco; Petr Sos ´ ik

415

Replicated document management in a group communication system  

Microsoft Academic Search

This paper is about the design and implementatbn of a repllwted database that forms the basis for the N&s*gray, communication system The system supports groups of people working on shared sets of donunents and is intended jor use in a perso~l computer network enulronment in which the database servers are 'tarely connected\\

Leonard Kawell Jr.; Steven Beckhardt; Timothy Halvorsen; Raymond Ozzie; Irene Greif

1988-01-01

416

Multiple CFOs compensation and BER analysis for cooperative communication systems  

Microsoft Academic Search

In cooperative communication systems, multiple carrier frequency offsets (MCFO) appear due to the different accuracy of the nodes' oscillators and Doppler spreads, which drastically degrades the performance of space-frequency block coded (SFBC) cooperative systems. In this paper, a MCFO compensation algorithm including modified SFBC decoder, minimum Euclidean distance decision criterion and interference reconstructing eliminator is proposed. Besides, the bit error

Yanyan Zhang; Jianhua Zhang

2009-01-01

417

Kansas Communication and Instruction System through Fiber-Optic Transmission.  

ERIC Educational Resources Information Center

Schools and communities will restructure as they move into the next decade. The success of this restructuring will be dependent upon access to and sharing of quality teaching and information through an expanded communication system. One of the major two-way interactive technologies is the fiber-optic cable: a delivery system that will provide…

Kansas State Dept. of Education, Topeka.

418

An OFDM system Optimization for Satellite Communication in Ka Band  

Microsoft Academic Search

An OFDM system optimization for satellite communication in Ka band is estimated in terms of the Shannon theory. The analysis covers a novel closed-form expression for the optimal subcarriers, with respect to the maximization of the achieved spectral efficiency, expressed in terms of the theoretically Shannon channel capacity available to each system's user.

Da Xin-yu; Zhu Hai-feng

2008-01-01

419

[An integrated system of blood pressure measurement with bluetooth communication].  

PubMed

The development of the integrated blood pressure system with bluetooth communication function is introduced. Experimental results show that the system can complete blood pressure measurement and data transmission wireless effectively, which can be used in m-Health in future. PMID:23189635

Wang, Wei; Wang, Jing; Sun, Hongyang; Xu, Zuyang; Chai, Xinyu

2012-07-01

420

Theory Construction in the Study of Communication: The System Paradigm.  

ERIC Educational Resources Information Center

The process of explanation as defined by the covering law model of science contains stringent criteria which often cannot be met by communication scientists. An alternative model, less powerful but more obtainable--the system paradigm--should be adopted. Four types of explanation provide a context for a discussion of the system paradigm…

Monge, Peter R.

421

An overview of limited feedback in wireless communication systems  

Microsoft Academic Search

It is now well known that employing channel adaptive signaling in wireless communication systems can yield large improvements in almost any performance metric. Unfortunately, many kinds of channel adaptive techniques have been deemed impractical in the past because of the problem of obtaining channel knowledge at the transmitter. The transmitter in many systems (such as those using frequency division duplexing)

David James Love; Robert W. Heath Jr.; Vincent K. N. Lau; David Gesbert; Bhaskar D. Rao; Matthew Andrews

2008-01-01

422

Computer communications through telecommunications satellite systems - The NADIR project  

Microsoft Academic Search

Current developments in satellite digital communication in Europe are surveyed, and the status of the French NADIR project begun in 1980 is reported. The geographic coverage, transmission rates, propagation delays, broadcasting and multidestination channels, and error rates characteristic of present satellite systems are discussed, and the specific performance parameters of the Telecom-1 system, comprising three geosynchronous satellites (one operational and

J.-L. Grange

1983-01-01

423

Employing cooperative diversity for performance enhancement in UWB communication systems  

Microsoft Academic Search

Due to limitation on transmitted power level, any UWB system faces major design challenges in achieving wide coverage while assuring an adequate system performance. In this paper, an employment of cooperative communications in UWB is proposed to enhance the performance and the coverage of UWB by exploiting the broadcasting nature of wireless channels and the cooperation among UWB devices. Symbol-error-rate

W. Pam Siriwongpairat; Weifeng Su; Zhu Han; K. J. Ray Liu

2006-01-01

424

Floating avatar: telepresence system using blimps for communication and entertainment  

Microsoft Academic Search

We developed a floating avatar system that integrates a blimp with a virtual avatar to create a unique telepresence system. Our blimp works as an avatar and contains several pieces of equipment, including a projector and a speaker as the output functions. Users can communicate with others by transmitting their facial image through the projector and voice through the speaker.

Hiroaki Tobita; Shigeaki Maruyama; Takuya Kuzi

2011-01-01

425

A queuing model for meteor burst packet communication systems  

Microsoft Academic Search

A discrete-time queuing model for the performance of a meteor-burst packet communication system is analyzed using matrix analytic methods. Not only is the system subject to interruptions due to the intermittence of the ionization layer, but its analysis is further complicated by the necessity to retransmit packets that have error or that occur at the tail end of a period

Y. Chandramouli; M. F. Neuts; V. Ramaswami

1989-01-01

426

Secure Vehicular Communication Systems: Implementation, Performance, and Research Challenges  

Microsoft Academic Search

Vehicular Communication (VC) systems are on the verge of practical deployment. Nonetheless, their security and privacy protection is one of the problems that have been addressed only recently. In order to show the feasibility of secure VC, certain implementations are required. In [1] we discuss the design of a VC security system that has emerged as a result of the

Frank Kargl; Panagiotis Papadimitratos; Levente Buttyán; M. Muter; Björn Wiedersheim; Elmar Schoch; Ta-Vinh Thong; Giorgio Calandriello; Albert Held; Antonio Kung; Jean-pierre Hubaux

2008-01-01

427

Breaking two secure communication systems based on chaotic masking  

Microsoft Academic Search

This paper describes the security weakness of two generalized nonlinear state-space observers-based approaches for both chaos synchronization and secure communication, using chaotic masking and chaotic modulation of a Lorenz system. We show that the security is compromised without any knowledge of the chaotic system parameter values and even without knowing the transmitter structure.

G. Alvarez; F. Montoya; M. Romera; G. Pastor

2004-01-01

428

Wireless Secure Communication Systems Design Based on Chaotic Synchronization  

Microsoft Academic Search

In order to solve security of data transmission in wireless network, a secure communication method based on chaotic synchronization is presented. By designing nonlinear state observer, two chaotic systems are constructed and kept synchronized, realizing the complete recovery of the encrypted signal; the stability of the synchronized system is being analyzed at the same time. Simulation results show that the

Zhi-cheng Dai; Bing-wen Wang; Peng Li

2006-01-01

429

Timing requirements for the Sanguine ELF communications system  

NASA Technical Reports Server (NTRS)

The development of an extremely low frequency (ELF) communications system for command and control of naval forces is discussed. The basic requirements for the system are defined. Emphasis is placed on the clock requirements based on phase or time rather than frequency. The time and frequency requirements at the transmitter stations are tabulated.

Kruger, B.

1972-01-01

430

Systems analysis of the space shuttle. [communication systems, computer systems, and power distribution  

NASA Technical Reports Server (NTRS)

Developments in communications systems, computer systems, and power distribution systems for the space shuttle are described. The use of high speed delta modulation for bit rate compression in the transmission of television signals is discussed. Simultaneous Multiprocessor Organization, an approach to computer organization, is presented. Methods of computer simulation and automatic malfunction detection for the shuttle power distribution system are also described.

Schilling, D. L.; Oh, S. J.; Thau, F.

1975-01-01

431

Communication  

Microsoft Academic Search

\\u000a Communication impairment is a core deficit associated with autism spectrum disorder (ASD). Therefore, it should not be surprising\\u000a that this topic has become a major thrust of assessment and treatment in applied behavior analysis (ABA). The types of communication\\u000a skills to target for intervention and the behavioral assessment methods that can be used to identify these target behaviors\\u000a are reviewed

Jeff Sigafoos; Mark F. O’Reilly; Giulio E. Lancioni

432

Engineering calculations for communications satellite systems planning  

NASA Technical Reports Server (NTRS)

Computer-based techniques for optimizing communications-satellite orbit and frequency assignments are discussed. A gradient-search code was tested against a BSS scenario derived from the RARC-83 data. Improvement was obtained, but each iteration requires about 50 minutes of IBM-3081 CPU time. Gradient-search experiments on a small FSS test problem, consisting of a single service area served by 8 satellites, showed quickest convergence when the satellites were all initially placed near the center of the available orbital arc with moderate spacing. A transformation technique is proposed for investigating the surface topography of the objective function used in the gradient-search method. A new synthesis approach is based on transforming single-entry interference constraints into corresponding constraints on satellite spacings. These constraints are used with linear objective functions to formulate the co-channel orbital assignment task as a linear-programming (LP) problem or mixed integer programming (MIP) problem. Globally optimal solutions are always found with the MIP problems, but not necessarily with the LP problems. The MIP solutions can be used to evaluate the quality of the LP solutions. The initial results are very encouraging.

Reilly, C. H.; Levis, C. A.; Mount-Campbell, C.; Gonsalvez, D. J.; Wang, C. W.; Yamamura, Y.

1985-01-01

433

A high-sensitivity small animal SPECT system  

NASA Astrophysics Data System (ADS)

Medical imaging using single gamma-ray-emitting radionuclides typically makes use of parallel hole collimators or pinholes in order to achieve good spatial resolution. However, a tradeoff in sensitivity is inherent in the use of a collimator, and modern preclinical single photon emission computed tomography (SPECT) systems detect a very small fraction of emitted gamma rays, often less than 0.1%. A system for small animal SPECT imaging which uses no collimators could potentially achieve very high sensitivity—several tens of percent—with reasonably sized detectors. This would allow two significant improvements in preclinical studies: images could be obtained more rapidly, allowing higher throughput for screening applications, or for dynamic processes to be observed with very good time resolution; and images could be obtained with less radioactive tracer, making possible the in vivo imaging of low-capacity receptor systems, aiding research into new tracer compounds, and reducing the cost and easing the regulatory burden of an experiment. Of course, a system with no collimator will not be able to approach the submillimeter spatial resolutions produced by the most advanced pinhole and collimated systems, but a high-sensitivity system with resolution of order 1 cm could nonetheless find significant and new use in the many molecular imaging applications which do not require good spatial resolution—for example, screening applications for drug development or new imaging agents. Rather than as an alternative to high-resolution SPECT systems, the high-sensitivity system is proposed as a radiotracer alternative to optical imaging for small animals. We have developed a prototype system for mouse imaging applications. The scanner consists of two large, thin, closely spaced scintillation detectors. Simulation studies indicate that a FWHM spatial resolution of 7 mm is possible. In an in vivo mouse imaging study using the 99mTc labeled tracer MAG-3, the sensitivity of the system is measured to be 40%. Simple projection images created by analytically combining the two detectors' data show sufficient resolution to observe the dynamic distribution of the radiotracer in the mouse.

Mitchell, Gregory S.; Cherry, Simon R.

2009-03-01

434

A Broadcast Vehicle to Vehicle Communication System in Railway Environments  

Microsoft Academic Search

Current statistics in railway transportation systems show that the number of accidents is still too high, despite of huge investments in infrastructure-based safety systems. We show that a infrastructure-less cross-layer train-to-train commu- nication system exploiting all characteristics of a pervasive computing system, like direct communication in mobile ad- hoc networks (MANETs), exchange of location and other relevant context information provided

Cristina Rico García; Thomas Strang; Andreas Lehner

2008-01-01

435

Secure optical communication system utilizing deformable MEMS mirrors  

NASA Astrophysics Data System (ADS)

An optical communication system suitable for voice, data retrieval from remote sensors and identification is described. The system design allows operation at ranges of several hundred meters. The heart of the system is a modulated MEMS mirror that is electrostatically actuated and changes between a flat reflective state and a corrugated diffractive state. A process for mass producing these mirrors at low cost was developed and is described. The mirror was incorporated as a facet in a hollow retro-reflector, allowing temporal modulation of an interrogating beam and the return of the modulated beam to the interrogator. This system thus consists of a low power, small and light communication node with large (about 60°) angular extent. The system's range and pointing are determined by the interrogator /detector/demodulator (Transceiver) unit. The transceiver is comprised of an optical channel to establish line of sight communication, an interrogating laser at 1550nm, an avalanche photo diode to detect the return signal and electronics to drive the laser and demodulate the detected signal and convert it to an audio signal. A functional prototype system was built using a modified compact optical sight as the transceiver. Voice communication in free space was demonstrated. The design and test of major components and the complete system are discussed.

Ziph-Schatzberg, Leah; Bifano, Thomas; Cornelissen, Steven; Stewart, Jason; Bleier, Zvi

2009-02-01

436

Multiple-antenna communication systems: An emerging technology Syst` emes de communications multi-antennes: une technologie ´ emergeante  

Microsoft Academic Search

A recent development in wireless communications is the application of multiple-input multiple-output (MIMO) systems to radio communications via use of multiple antennas. In order to investigate the technology's potential, an experimental MIMO system containing two four-element antenna arrays ( ) has been developed at the University of Alberta. The system is used to obtain MIMO channel measurements in a typical

Paul Goud Jr; Christian Schlegel; Witold A. Krzymien; Robert Hang

437

Integrated Hybrid-Simulation of Electric Power and Communications Systems  

SciTech Connect

The modern power grid is strongly integrated with its communication network. While a power system primarily consists of elements that are modeled by continuous equations, a communication system has discrete event dynamics. We model the integrated operation of these two systems with a hybrid modeling and simulation technique. Systematically combining continuous and discrete event system models is necessary for correctly simulating critical system behaviors. This paper discusses an approach based on the discrete event system specification (DEVS) that characterizes the interaction of the two systems formally to preserve simulation correctness. We demonstrate the implementation of our integrated hybrid simulation technique with detailed generator and network models in a wide-area cooperative automatic load-control scenario.

Nutaro, James J [ORNL; Kuruganti, Phani Teja [ORNL; Miller, Laurie E [ORNL; Mullen, Sara [ORNL; Shankar, Mallikarjun [ORNL

2007-01-01

438

Satellite systems requirements for land mobile communications  

NASA Technical Reports Server (NTRS)

The system design objective is to provide a satellite link through a gateway station, connecting mobile users in areas not served by a terrestrial cellular system to the switched telephone network (STN). The proposed frequency allocation comprises a pair of 10-MHz bands in the 806-890 MHz range specified by the 1979 World Administrative Radio Conference (WARC) for land-mobile satellite service (LMSS). The satellite design is constrained by projected STS capability with an upper stage of the wide-body Centaur or Integral Propulsion System (IPS) type. For the latter (a TRW design), the payload is limited to approximately 10,400 lb. The design is to be based on 1990's technology, with initial operating capability scheduled for 1995. The satellite should be designed for a 7-year life. Mobile-unit compatibility with cellular system specifications is desirable, if consistent with other system requirements.

Horstein, M.

1983-01-01

439

Low level communication management for e-health systems  

NASA Astrophysics Data System (ADS)

The heterogeneity of e-health systems encourages the use of standards such as Health Level 7 (HL7v3) to ensure interoperability. Many actual implementations address this problem by unoptimized high level programming of top-range portable computing platforms. However, this approach could pose excessive demands on battery-powered mid-range terminals. In this work, we propose low-level support for portable HL7v3-compatible embedded systems in order to better exploit their limited processing and communications capabilities. In particular, we present our experience in mobile communication management through two different approaches, which proves the feasibility of this proposal.

Riva, Guillermo; Zerbini, Carlos; Voos, Javier; Centeno, Carlos; González, Eduardo

2011-12-01

440

Design and evaluation of control systems for large communications satellites  

NASA Technical Reports Server (NTRS)

Control techniques for future large flexible spacecraft are developed. Control design and analysis are supported by a comprehensive CAD system. The proposed operational mobile communications satellite (OMSAT) featuring a 44 m offset fed antenna is used as target application. Requirements for satellite attitude control and communications beam pointing are defined. The following control methods are applied to the system: standard linear optimal regulator (LOR) with Luenberger observer, LOR/observer with selective spill-over suppression, frequency shaped LOR, LOR with closed-loop order reduction by cost decoupling, and robust servomechanism.

Steiber, M. E.

1985-01-01

441

Study and design on USB wireless laser communication system  

NASA Astrophysics Data System (ADS)

We give the definition of USB wireless laser communication system (WLCS) and the brief introduction to the protocol of USB, the standard of hardware is also given. The paper analyses the hardware and software of USB WLCS. Wireless laser communication part and USB interface circuit part are discussed in detail. We also give the periphery design of the chip AN2131Q, the control circuit to realize the transformation from parallel port to serial bus, and the circuit of laser sending and receiving of laser communication part, which are simply, cheap and workable. And then the four part of software are analyzed as followed. We have consummated the ISR in the firmware frame to develop the periphery device of USB. We have debugged and consummated the 'ezload,' and the GPD of the drivers. Windows application performs functions and schedules the corresponding API functions to let the interface practical and beautiful. The system can realize USB wireless laser communication between computers, which distance is farther than 50 meters, and top speed can be bigger than 8 Mbps. The system is of great practical sense to resolve the issues of high-speed communication among increasing districts without fiber trunk network.

Wang, Aihua; Zheng, Jiansheng; Ai, Yong

2004-04-01

442

ROBUS-2: A Fault-Tolerant Broadcast Communication System  

NASA Technical Reports Server (NTRS)

The Reliable Optical Bus (ROBUS) is the core communication system of the Scalable Processor-Independent Design for Enhanced Reliability (SPIDER), a general-purpose fault-tolerant integrated modular architecture currently under development at NASA Langley Research Center. The ROBUS is a time-division multiple access (TDMA) broadcast communication system with medium access control by means of time-indexed communication schedule. ROBUS-2 is a developmental version of the ROBUS providing guaranteed fault-tolerant services to the attached processing elements (PEs), in the presence of a bounded number of faults. These services include message broadcast (Byzantine Agreement), dynamic communication schedule update, clock synchronization, and distributed diagnosis (group membership). The ROBUS also features fault-tolerant startup and restart capabilities. ROBUS-2 is tolerant to internal as well as PE faults, and incorporates a dynamic self-reconfiguration capability driven by the internal diagnostic system. This version of the ROBUS is intended for laboratory experimentation and demonstrations of the capability to reintegrate failed nodes, dynamically update the communication schedule, and tolerate and recover from correlated transient faults.

Torres-Pomales, Wilfredo; Malekpour, Mahyar R.; Miner, Paul S.

2005-01-01

443

Experimental millimeter-wave personal satellite communications system  

NASA Technical Reports Server (NTRS)

Communications Research Laboratory (CRL) has investigated an advanced millimeter (mm)-wave satellite communications system for personal use. Experiments in mm-wave personal satellite communication are to be conducted for 3 years using Japan's Engineering Test Satellite VI (ETS-VI). This paper describes an experimental mm-wave (43/38 GHz) personal satellite communication system, including an onboard transponder and an earth terminal. The on-board transponder is almost completed, and the ground experiment system is still in the design stage. The transponder employs advanced mm-wave solid state technology. It uses 38 GHz high power solid state amplifiers to accelerate the development of mm-wave solid state devices which are indispensable to personal earth terminals. The transponder consists of a 43 GHz receiver with a built-in low noise amplifier, an IF filter section with very narrow bandwidth to improve the carrier-to-noise power ratio of the weak personal communication signal, and two high power amplifiers using newly developed high power Gallium Arsenide (GaAs) metal-semiconductor field effect transistors (MESFETs).

Suzuki, Yoshiaki; Kimura, Shigeru; Shimada, Masaaki; Tanaka, Masato; Takahashi, Yasuhiro

1991-01-01

444

Optical data communication for Earth observation satellite systems  

NASA Astrophysics Data System (ADS)

The current development status of optical communication engineering in comparison to the conventional microwave systems and the different configurations of the optical data communication for Earth observation satellite systems are described. An outlook to future optical communication satellite systems is given. During the last decade Earth observation became more and more important for the extension of the knowledge about our planet and the human influence on nature. Today pictures taken by satellites are used, for example, to discover mineral resources or to predict harvest, crops, climate, and environment variations and their influence on the population. A new and up to date application for Earth observation satellites can be the verification of disarmament arrangements and the control of crises areas. To solve these tasks a system of Earth observing satellites with sensors tailored to the envisaged mission is necessary. Besides these low Earth orbiting satellites, a global Earth observation system consists of at least two data relay satellites. The communication between the satellites will be established via Inter-Satellite Links (ISL) and Inter-Orbit Links (IOL). On these links, bitrates up to 1 Gbit/s must be taken into account. Due to the increasing scarcity of suitable frequencies, higher carrier frequencies must probably be considered, and possible interference with terrestrial radio relay systems are two main problems for a realization in microwave technique. One important step to tackle these problems is the use of optical frequencies for IOL's and ISL's.

Fischer, J.; Loecherbach, E.

1991-10-01

445

Applying Model Based Systems Engineering to NASA's Space Communications Networks  

NASA Technical Reports Server (NTRS)

System engineering practices for complex systems and networks now require that requirement, architecture, and concept of operations product development teams, simultaneously harmonize their activities to provide timely, useful and cost-effective products. When dealing with complex systems of systems, traditional systems engineering methodology quickly falls short of achieving project objectives. This approach is encumbered by the use of a number of disparate hardware and software tools, spreadsheets and documents to grasp the concept of the network design and operation. In case of NASA's space communication networks, since the networks are geographically distributed, and so are its subject matter experts, the team is challenged to create a common language and tools to produce its products. Using Model Based Systems Engineering methods and tools allows for a unified representation of the system in a model that enables a highly related level of detail. To date, Program System Engineering (PSE) team has been able to model each network from their top-level operational activities and system functions down to the atomic level through relational modeling decomposition. These models allow for a better understanding of the relationships between NASA's stakeholders, internal organizations, and impacts to all related entities due to integration and sustainment of existing systems. Understanding the existing systems is essential to accurate and detailed study of integration options being considered. In this paper, we identify the challenges the PSE team faced in its quest to unify complex legacy space communications networks and their operational processes. We describe the initial approaches undertaken and the evolution toward model based system engineering applied to produce Space Communication and Navigation (SCaN) PSE products. We will demonstrate the practice of Model Based System Engineering applied to integrating space communication networks and the summary of its results and impact. We will highlight the insights gained by applying the Model Based System Engineering and provide recommendations for its applications and improvements.

Bhasin, Kul; Barnes, Patrick; Reinert, Jessica; Golden, Bert

2013-01-01

446

Research on Agent Communication Model and Its Application in Electric System  

Microsoft Academic Search

It is important of Agent communication for the reality of coordination, cooperation and consistency in multi-Agent system. In this paper, an architecture of Agent communication is given. In order to decrease the working capacity to maintain the communication protocol, using the KQML as the basic Agent communication language, the paper proposes an Agent communication model based on dynamic modification to

TAOW EI WANG; QIN W ANG; KUN GAO; YIBO REN; Taowei Wang; Qin Wang

447

Integrated communication and control systems. I - Analysis  

NASA Technical Reports Server (NTRS)

The paper presents the results of an ICCS analysis focusing on discrete-time control systems subject to time-varying delays. The present analytical technique is applicable to integrated dynamic systems such as those encountered in advanced aircraft, spacecraft, and the real-time control of robots and machine tools via a high-speed network within an autonomous manufacturing environment. The significance of data latency and missynchronization between individual system components in ICCS networks is discussed in view of the time-varying delays.

Halevi, Yoram; Ray, Asok

1988-01-01

448

Dependability analysis of the data communication system in train control system  

Microsoft Academic Search

Communication based train control (CBTC) system is based on mobile communication and overcomes fixed blocks in order to increase\\u000a track utilization and train safety. The data communication system (DCS) between trains and wayside equipment is a crucial\\u000a factor for the safe and efficient operation of CBTC system. The dependability under various transmission conditions needs\\u000a to be modeled and evaluated. In

TianHua Xu; Tao Tang; ChunHai Gao; BaiGen Cai

2009-01-01

449

Method and apparatus for animal positioning in imaging systems  

DOEpatents

An apparatus for imaging an animal includes a first mounting surface, a bed sized to support the animal and releasably secured to or integral with the first mounting surface. The apparatus also includes a plurality of straps, each having a first end in a fixed position relative to the bed and a second end for tightening around a limb of the animal. A method for in-vivo imaging of an animal includes providing an animal that has limbs, providing a first mounting surface, and providing a bed removably secured to or integral with the mounting surface and sized to support the animal as well as being coupled to a plurality of straps. The method also includes placing the animal on the bed between the plurality of straps and tightening at least two of the plurality of straps around at least two of the limbs such that the animal is substantially secured in place relative to the bed.

Hadjioannou, Arion-Xenofon; Stout, David B.; Silverman, Robert W.

2013-01-01

450

Improved communication system for large operations center  

NASA Technical Reports Server (NTRS)

When several microphones are fed into a common system, sound originating at any given source results in poor articulation. Introduction of an automatic microphone priority control suppresses echo and reverberation.

Draper, M. S.

1968-01-01

451

Performance Information Management System (PIMS) Communication.  

National Technical Information Service (NTIS)

The objective of this project is to modify and enhance the capabilities of the Mailnet telephonic bulletin board system and create 'hooks' for accessing a performance database remotely.... Telecommunications, Bulletin board, RA V, Performance, Analysis.

K. P. Winter

1992-01-01

452

Parallel communicating grammar systems with terminal transmission  

Microsoft Academic Search

Summary.   We introduce a new variant of PC grammar systems, called PC grammar systems with terminal transmission, PCGSTT for short.\\u000a We show that right-linear centralized PCGSTT have nice formal language theoretic properties: they are closed under gsm mappings\\u000a (in particular, under intersection with regular sets and under homomorphisms) and union; a slight variant is, in addition,\\u000a closed under concatenation and

Henning Fernau

2001-01-01

453

Development of a triple modality small animal planar imaging system  

SciTech Connect

Recently small animal research utilizing nuclear medicine based imaging has been combined with structural anatomical imaging from x-ray radiography providing a powerful tool for animal researchers. The addition of a third modality is the goal of our instrumentation development. Thomas Jefferson National Accelerator Facility and Case Western Reserve University have been collaborating on the development of a planar imaging system which in addition to radiopharmaceutical based functional imaging and x-ray radiography structural imaging also allows for the in vivo bioluminescence imaging thus providing another functional imaging modality. For the gamma camera we use is a Hamamatsu position sensitive photomultiplier tube coupled to a pixellated NaI(TI) scintillator array with individual crystal elements 1 mm × 1 mm × 5 mm in size and a 0.25 mm septum between each element. The gamma camera has a 10 cm diameter active area and can be used for 125I, 99mT and 111In radionuclide imaging. To acquire anatomical information we are using a Rad-Icon Shad-o-Box X-ray detector that provides a field of view of 5 cm × 10 cm. The x-ray source is a Source-Ray compact x-ray generator. We are using a Princeton Instruments cooled CCD based detector for the imaging of the bio-distribution of bioluminescence. All three imaging instruments will be integrated into a single light tight / x-ray tight enclosure.

A. G. Weisenberger, Z. Lee, S. Majewski, B. Kross, V. Popov, B. Welch, R. Wojcik, C. Zorn

2006-02-01

454

Low-power FLC-based retromodulator communications system  

NASA Astrophysics Data System (ADS)

On September 15, 1996, researchers from Utah State University/Space Dynamics Lab in conjunction with Phillips Lab/Starfire Optical Range and Kjome Research successfully flew and tested a retromodulator laser communication package on a high altitude balloon. This paper addresses the layout and hardware used for the communication link, as well as presenting some preliminary data collected during the 6 hour flight of the balloon. The package was a proof of concept demonstration system for a low-power laser communications systems for small, low Earth orbiting satellites. The ferroelectric liquid crystal based retromodulator design of Utah State provided test patterns for modulation rates up to 20 kilo bits per second. Data was successfully downlinked using a 1200 bps RS232 format and a simplistic receiver. The Starfire Optical Range 1.5-meter telescope located on Kirtland AFB, tracked the balloon, which reached a float altitude of 31 km and collected the modulated light reflected from the payload.

Swenson, Charles M.; Steed, Clark A.; de La Rue, Imelda A.; Fugate, Robert Q.

1997-05-01

455

Plastic optical fiber serial communications link for distributed control system  

NASA Astrophysics Data System (ADS)

One of the most common interface for communications specified is RS 232C standard. Though widely accepted, RS232 has limited transmission speed, range and networking capabilities. RS 422 standard overcomes limitations by using differential signal lines. In automation of the operation of gas discharge lasers, multiple processors are used for control of lasers, cooling system, vacuum system etc. High EMI generated by lasers interfere through galvanic transmission or by radiation over the length of cables, and hang up operation of processors or control PC. A serial communications link was designed eliminating copper transmission media, using plastic optical fiber cables and components, to connect local controllers with the master PC working on RS232 protocols. The paper discusses the design and implementation of a high ly reliable EMI harden serial communications link.

Saxena, Piyush; Sharangpani, K. K.; Vora, H. S.; Nakhe, S. V.; Jain, R.; Shenoy, N. M.; Bhatnagar, R.; Shirke, N. D.

2001-09-01

456

Aeronautical Mobile Airport Communications System (AeroMACS)  

NASA Technical Reports Server (NTRS)

To help increase the capacity and efficiency of the nation s airports, a secure wideband wireless communications system is proposed for use on the airport surface. This paper provides an overview of the research and development process for the Aeronautical Mobile Airport Communications System (AeroMACS). AeroMACS is based on a specific commercial profile of the Institute of Electrical and Electronics Engineers (IEEE) 802.16 standard known as Wireless Worldwide Interoperability for Microwave Access or WiMAX (WiMax Forum). The paper includes background on the need for global interoperability in air/ground data communications, describes potential AeroMACS applications, addresses allocated frequency spectrum constraints, summarizes the international standardization process, and provides findings and recommendations from the world s first AeroMACS prototype implemented in Cleveland, Ohio, USA.

Budinger, James M.; Hall, Edward

2011-01-01

457

Reactive system verification case study: Fault-tolerant transputer communication  

NASA Technical Reports Server (NTRS)

A reactive program is one which engages in an ongoing interaction with its environment. A system which is controlled by an embedded reactive program is called a reactive system. Examples of reactive systems are aircraft flight management systems, bank automatic teller machine (ATM) networks, airline reservation systems, and computer operating systems. Reactive systems are often naturally modeled (for logical design purposes) as a composition of autonomous processes which progress concurrently and which communicate to share information and/or to coordinate activities. Formal (i.e., mathematical) frameworks for system verification are tools used to increase the users' confidence that a system design satisfies its specification. A framework for reactive system verification includes formal languages for system modeling and for behavior specification and decision procedures and/or proof-systems for verifying that the system model satisfies the system specifications. Using the Ostroff framework for reactive system verification, an approach to achieving fault-tolerant communication between transputers was shown to be effective. The key components of the design, the decoupler processes, may be viewed as discrete-event-controllers introduced to constrain system behavior such that system specifications are satisfied. The Ostroff framework was also effective. The expressiveness of the modeling language permitted construction of a faithful model of the transputer network. The relevant specifications were readily expressed in the specification language. The set of decision procedures provided was adequate to verify the specifications of interest. The need for improved support for system behavior visualization is emphasized.

Crane, D. Francis; Hamory, Philip J.

1993-01-01

458

A general analysis of anti-jam communication systems  

NASA Technical Reports Server (NTRS)

A general error bound is derived for a general anti-jam communication system which will serve as the basis for evaluating the performance of all such complex communication systems. The two most common spread spectrum techniques, coherent DS/BPSK and noncoherent FH/MFSK, are analyzed. Pulse jamming represents the worst type of jammer for DS/BPSK systems, and several receiver structures against such a jammer are examined. It is found that for low values of chip energy-to-noise ratios of O dB or less there is little difference between having or not having jammer state knowledge with a hard decision receiver. Soft decision receivers are shown to be useless against very narrow pulses without jammer state knowledge. Partial band jammers are close to the worst case jammer for FH/MFSK systems. The conclusions found for these systems are similar to those for the DS/BPSK systems.

Omura, J. K.; Levitt, B. K.

1981-01-01

459

Physical Geography: Science and Systems of the Human Environment; Animations  

NSDL National Science Digital Library

This website contains Flash animations and real footage movies (QuickTime format) from a physical geography textbook. Animations show phenomena associated with the atmosphere, biosphere, lithosphere, and hydrosphere/cryosphere. Animations are slow to download and cannot be rewound to stress important points. Users may also follow links to PowerPoint slides, interactive activities, an image library and an instructor's manual.

Strahler, Alan H.; University, Boston; Education, Wiley H.

460

Making recombinant proteins in animals – different systems, different applications  

Microsoft Academic Search

Transgenic animal bioreactors represent a powerful tool to address the growing need for therapeutic recombinant proteins. The ability of transgenic animals to produce complex, biologically active recombinant proteins in an efficient and economic manner has stimulated a great deal of interest in this area. As a result, genetically modified animals of several species, expressing foreign proteins in various tissues, are

Michael K. Dyck; Dan Lacroix; François Pothier; Marc-André Sirard

2003-01-01

461

Solid state laser communications in space (SOLACOS) high data rate satellite communication system verification program  

NASA Astrophysics Data System (ADS)

This paper gives an overview on the current development status of the SOLACOS program and presents the highlights of the program. SOLACOS (Solid State Laser Communications in Space) is the national German program to develop a high performance laser communication system for high data rate transmission between LEO and GEO satellites (Inter Orbit Link, IOL). Two experimental demonstrator terminals are designed and developed in the SOLACOS program. The main development objectives are the Pointing Acquisition and Tracking subsystem (PAT) and the high data rate communication system. All key subsystems and components are straightway developed to be upgraded in follow- on projects to full space qualification. The main design objective for the system is a high degree of modularity which allows to easily upgrade the system with new upcoming technologies. Therefore, all main subsystems are interconnected via fibers to ease replacement of subsystems. The system implements an asymmetric data link with a 650 MBit/s return channel and a 10 MBit/s forward channel. The 650 MBit/s channel is based on a diode pumped Nd:YAG, Integrated Optics Modulator and uses the syncbit transmission scheme. In the syncbit system synchronization information which is necessary to maintain phase lock of the local oscillator of the coherent receiver is transmitted time multiplexed into the data stream. The PAT system comprises two beam detection sensors and three beam steering elements. For initial acquisition and tracking of the remote satellite a high speed CCD camera with an integrated image processing unit, the Acquisition and Tracking Sensor (ATS) is used. In the tacking mode the beam position is sensed via the Fibernutator sensor which is also used to couple the incoming signal into the receiver fiber. Incoming and outgoing beams are routed through the telescopes which are positioned with a 2 axis gimbal mechanism and a high speed beam steering mirror. The PAT system is controlled by a digital signal processor. For beam control advanced PAT algorithms are under development.

Pribil, Klaus; Flemmig, Joerg

1994-09-01

462

The Globalstar mobile satellite system for worldwide personal communications  

NASA Technical Reports Server (NTRS)

Loral Aerospace Corporation along with Qualcomm Inc. have developed a satellite system which offers global mobile voice and data services to and from handheld and mobile user terminals with omni-directional antennas. By combining the use of low-earth orbit (LEO) satellites with existing terrestrial communications systems and innovative, highly efficient spread spectrum techniques, the Globalstar system provides users with low-cost, reliable communications throughout the world. The Globalstar space segment consists of a constellation of 48 LEO satellites in circular orbits with 750 NM (1389 km) altitude. Each satellite communicates with the mobile users via the satellite-user links and with gateway stations. The gateway stations handle the interface between the Globalstar network and the OSTN/PLMN systems. Globalstar transceivers are similar to currently proposed digital cellular telephones in size and have a serial number that will allow the end user to make and receive calls from or to that device anywhere in the world. The Globalstar system is designed to operate as a complement to existing local, long-distance, public, private and specialized telecommunications networks. Service is primarily designed to serve the rural and thin route communications needs of consumers, government users, and private networks.

Wiedeman, Robert A.; Viterbi, Andrew J.

1993-01-01

463

A Low Earth Orbit satellite marine communication system demonstration  

NASA Technical Reports Server (NTRS)

An application of Low Earth Orbit (LEO) satellite communications technology was investigated during a joint Canadian/American scientific expedition to the north pole in the summer of 1994. The Canadian ice breaker involved, was equipped with a store-and-forward LEO satellite terminal which was linked to a ground station in St. John's, Newfoundland, via the near-polar-orbiting satellite, HealthSat-l. The objective was to evaluate the performance of such a system while providing an alternate means of communications in the far north. The system performed well, given its inherent limitations. All 151 attempts to send data files to the ship were successful. Only two (2) of the 35 attempts to send files from the ship were unsuccessful. The files ranged in size from 0.1 to 60 Kbytes. In the high arctic, above 80 deg north, this system often provided the only practical means of data communications. This experiment demonstrated the potential of such a system for not-real-time communications with remote and/or mobile stations, and highlighted the many issues involved. This paper describes the project objectives, system configuration and experimental procedure used, related technical issues, trial results, future work, and conclusions.

Elms, T. Keith; Butt, Kenneth A.; Asmus, Ken W.

1995-01-01

464

Underwater acoustic communication experimentation: The acoustic communications and data storage (ACDS) system  

NASA Astrophysics Data System (ADS)

The Naval Research laboratory has developed a sea-going system, currently consisting of three acoustic communications and data storage (ACDS) buoys. The buoys can be deployed in the water column, moored to the ocean floor, or towed behind a ship to emulate an autonomous underwater vehicle (AUV). The system is intended for semi-real-time acoustic communications in situ and continuous recording of the raw acoustic data in the water for postexperiment analysis. The purpose is to study environmental issues affecting high data rate point-to-point acoustic communications as well as multiple-in-multiple-out acoustic networking. Each ACDS has an acoustic projector and an array of eight hydrophones. It is designed for two frequency bands: 2-5 kHz and 15-25 kHz. The system has been deployed in several oceans. Modulation signals used include binary and quadrature phase-shifted keying (BPSK/QPSK), frequency-hopped frequency-shifted keying (FH FSK), orthogonal frequency division multiplexing (OFDM) and code division multiple access (CDMA) signals. The acoustic modem is based on the Acoustic Modem Software developed by WHOI and improved by the Naval Underwater Warfare Center, Newport, RI. Acoustic networking signals are used to aid vehicle navigation. [Work supported by ONR.

McCord, M.; Schindall, J.; Yang, T. C.; Gendron, P.; Yang, W.-B.

2001-05-01

465

Optical communication system performance with tracking error induced signal fading.  

NASA Technical Reports Server (NTRS)

System performance is determined for an optical communication system using noncoherent detection in the presence of tracking error induced signal fading assuming (1) binary on-off modulation (OOK) with both fixed and adaptive threshold receivers, and (2) binary polarization modulation (BPM). BPM is shown to maintain its inherent 2- to 3-dB advantage over OOK when adaptive thresholding is used, and to have a substantially greater advantage when the OOK system is restricted to a fixed decision threshold.

Tycz, M.; Fitzmaurice, M. W.; Premo, D. A.

1973-01-01

466

A Picture Archiving and Communication System Module for Radiology  

PubMed Central

This paper presents the design and implementation of a clinical picture archiving and communication system (PACS) module within the radiology department of a 700-bed teaching hospital. The system is composed of an integrated network of digital devices used to electronically acquire, store, manage, and display radiological text and image information. Preliminary evaluation based on formal survey and usage statistics show that the system is rapidly being accepted by radiologists and clinicians for the review and processing of pediatric digital images.

Taira, Ricky K.

1988-01-01

467

Simulator study of multiterminal HVDC transmission system without fast communication  

SciTech Connect

AC/DC simulator studies for a 4-terminal HVDC system have been carried out to demonstrate the operating performance of the multi-terminal HVDC control scheme, ''the 2-ACR method'', which does not require fast communication systems. A microcomputer is used for converter control. Satisfactory operations have been confirmed through various types of simulations. Examples of an effective and economical DC circuit breaker application, for an AC system fault at the inverter and a DC line fault, are described.

Ishikawa, M.; Horiuchi, S.; Irokawa, S.; Imai, K.; Hirose, S.; Sekiya, K.

1986-07-01

468

Economics of buffer space provisioning in data communication systems  

Microsoft Academic Search

In data communication systems, system designers often face the quintessential dilemma of how much buffer space for storing packet or cell data is to be provided to satisfy performance requirements cost effectively. The dilemma is created by the pitfalls associated with the over-provisioning and the under-provisioning of buffer space. Over-provisioning of buffer space triggers increased system cost in terms of

S. Varada

2001-01-01

469

Domestic multibeam satellite communication system design and performance  

Microsoft Academic Search

The design and performance of a 1000-kg-class Ka\\/S-band multibeam satellite communications system for Japan are discussed. The Ka-band fixed multibeam satellite system includes a 4-beam antenna and 14 transponders switched at the intermediate frequency stage; the S-band mobile satellite system includes a 5-beam antenna and 5 transponders. The output power of the transponders is 10 W for the Ka-band and

Kazuhiro Miyauchi; Heiichi Yamamoto; Kozo Morita; Ken Kondo; Tetsuo Yasaka

1986-01-01

470

Bit Error Rate Calculation for Satellite Communication Systems  

Microsoft Academic Search

Simulations are mandatory to infer the performance of land mobile satellite (LMS) communication systems. For system availability calculations a versatile two-level simulation approach is proposed, which separates link- level and system-level simulations (1). The former aims at deriving statistics of coded bit error rate (BER) from propagation models, whereas the latter uses the results of the link-level simulation to calculate

Simon Saunders

471

Reconfigurability in future communication satellite systems  

NASA Astrophysics Data System (ADS)

Reconfigurability in the Broadcasting Satellite Service (BSS) and in the Fixed Satellite Service (FSS) is examined. The use in BSS of a common spare for different European national satellites is addressed, showing the feasibility of this solution for a system with three satellites in orbit. Solutions involving a repointable antenna with few feed horns and a fixed antenna with more feed horns are described. The use in FSS of a European system at Ku band for the latter 1990s is considered, describing a simplified reconfigurable FSS transmit front end.

Berretta, G.; Roederer, A.

472

Specification for installation of the crew activity planning system coaxial cable communication system  

NASA Technical Reports Server (NTRS)

The specification used to install a broadband coaxial cable communication system to support remote terminal operations on the Crew Activity Planning system at the Lyndon B. Johnson Space Center are reported. The system supports high speed communications between a Harris Slash 8 computer and one or more Sanders Graphic 7 displays.

Allen, M. A.; Roman, G. S.

1979-01-01

473

THROUGH-THE-EARTH (TTE) COMMUNICATIONS SYSTEM AND THE IN-MINE POWER LINE (IMPL) COMMUNICATIONS SYSTEM  

SciTech Connect

Work has progressed on both subsystems: the Through-the-Earth (TTE) Communications system and the In-Mine Power Line (IMPL) Communications system. The TTE system: The system was fabricated and repackaged as an industrial product enclosed in a commercial rugged, waterproof housing suitable for installation in mines. Features were added to the system to appeal to the preferences of different mine managers. Arrangements were made with NIOSH to install the system in the Lake Lynn underground mine for evaluation and demonstration to potential users. The IMPL system: Voice compression was successfully implemented and incorporated into the laboratory model. Compressed voice was transmitted through a power line, expanded at the receiving end, and received with high clarity.

Zvi H. Meiksin

2002-01-01

474

Comprehending emergent systems phenomena through direct-manipulation animation  

NASA Astrophysics Data System (ADS)

This study seeks to understand the type of interaction mode that best supports learning and comprehension of emergent systems phenomena. Given that the literature has established that students hold robust misconceptions of such phenomena, this study investigates the influence of using three types of interaction; speed-manipulation animation (SMN), post-manipulation animation (PMA) and direct-manipulation animation (DMA) for increasing comprehension and testing transfer of the phenomena, by looking at the effect of simultaneous interaction of haptic and visual channels on long term and working memories when seeking to comprehend emergent phenomena. The questions asked were: (1) Does the teaching of emergent phenomena, with the aid of a dynamic interactive modeling tool (i.e., SMA, PMA or DMA), improve students' mental model construction of systems, thus increasing comprehension of this scientific concept? And (2) does the teaching of emergent phenomena, with the aid of a dynamic interactive modeling tool, give the students the necessary complex cognitive skill which can then be applied to similar (near transfer) and/or novel, but different, (far transfer) scenarios? In an empirical study undergraduate and graduate students were asked to participate in one of three experimental conditions: SMA, PMA, or DMA. The results of the study found that it was the participants of the SMA treatment condition that had the most improvement in post-test scores. Students' understanding of the phenomena increased most when they used a dynamic model with few interactive elements (i.e., start, stop, and speed) that allowed for real time visualization of one's interaction on the phenomena. Furthermore, no indication was found that the learning of emergent phenomena, with the aid of a dynamic interactive modeling tool, gave the students the necessary complex cognitive skill which could then be applied to similar (near transfer) and/or novel, but different, (far transfer) scenarios. Finally, besides treatment condition, gender and age were also shown to be predictors of score differences; overall, males did better than females, and younger students did better than older students.

Aguirre, Priscilla Abel

475

Program Support Communications Network (PSCN) facsimile system directory  

NASA Technical Reports Server (NTRS)

This directory provides a system description, a station listing, and operating procedures for the Program Support Communications Network (PSCN) NASA Facsimile System. The NASA Facsimile System is a convenient and efficient means of spanning the distance, time, and cost of transmitting documents from one person to another. In the spectrum of communication techniques, facsimile bridges the gap between mail and data transmission. Facsimile can transmit in a matter of minutes or seconds what would take a day or more by mail delivery. The NASA Facsimile System is composed of several makes and models of facsimile machines. The system also supports the 3M FaxXchange network controllers located at Marshall Space Flight Center (MSFC).

1992-01-01

476

SYSTID - A flexible tool for the analysis of communication systems.  

NASA Technical Reports Server (NTRS)

Description of the System Time Domain Simulation (SYSTID) computer-aided analysis program which is specifically structured for communication systems analysis. The SYSTID program is user oriented so that very little knowledge of computer techniques and very little programming ability are required for proper application. The program is designed so that the user can go from a system block diagram to an accurate simulation by simply programming a single English language statement for each block in the system. The mathematical and functional models available in the SYSTID library are presented. An example problem is given which illustrates the ease of modeling communication systems. Examples of the outputs available are presented, and proposed improvements are summarized.

Dawson, C. T.; Tranter, W. H.

1972-01-01

477

Communications.  

ERIC Educational Resources Information Center

Five articles discussing communications in vocational education include "The Golden Rule of Administration" by Ben Mortensen; "Vital Link with Parents" by Richard Sullivan; "An Interpersonal Exercise" by John Villiers; "Face to Face with Employers" by Gregg Bosak; and "Recruitment Strategies" by Susan Miller. (SK)

Mortensen, Ben F.; And Others

1981-01-01

478

Auto tracking system for free space optical communications  

Microsoft Academic Search

This paper proposes a transceiver system for automatic tracking and dynamic routing for free space optical (FSO) communication. The proposed transceiver architecture has M transmitters and M receivers in a M x M configuration that can dynamically orient themselves at different angles to establish a link between two transceivers. A request to setup a lightpath is blocked if a free

Rabindra Ghimire; Seshadri Mohan

2011-01-01

479

Sensor and transmitter system for communication in pipelines  

DOEpatents

A system for sensing and communicating in a pipeline that contains a fl