The network and transmission of based on the principle of laser multipoint communication

NASA Astrophysics Data System (ADS)

Fu, Qiang; Liu, Xianzhu; Jiang, Huilin; Hu, Yuan; Jiang, Lun

2014-11-01

Space laser communication is the perfectly choose to the earth integrated information backbone network in the future. This paper introduces the structure of the earth integrated information network that is a large capacity integrated high-speed broadband information network, a variety of communications platforms were densely interconnected together, such as the land, sea, air and deep air users or aircraft, the technologies of the intelligent high-speed processing, switching and routing were adopt. According to the principle of maximum effective comprehensive utilization of information resources, get accurately information, fast processing and efficient transmission through inter-satellite, satellite earth, sky and ground station and other links. Namely it will be a space-based, air-based and ground-based integrated information network. It will be started from the trends of laser communication. The current situation of laser multi-point communications were expounded, the transmission scheme of the dynamic multi-point between wireless laser communication n network has been carefully studied, a variety of laser communication network transmission schemes the corresponding characteristics and scope described in detail , described the optical multiplexer machine that based on the multiport form of communication is applied to relay backbone link; the optical multiplexer-based on the form of the segmentation receiver field of view is applied to small angle link, the optical multiplexer-based form of three concentric spheres structure is applied to short distances, motorized occasions, and the multi-point stitching structure based on the rotation paraboloid is applied to inter-satellite communications in detail. The multi-point laser communication terminal apparatus consist of the transmitting and receiving antenna, a relay optical system, the spectroscopic system, communication system and communication receiver transmitter system. The communication forms of optical multiplexer more than four goals or more, the ratio of received power and volume weight will be Obvious advantages, and can track multiple moving targets in flexible.It would to provide reference for the construction of earth integrated information networks.

A chaotic secure communication scheme using fractional chaotic systems based on an extended fractional Kalman filter

NASA Astrophysics Data System (ADS)

Kiani-B, Arman; Fallahi, Kia; Pariz, Naser; Leung, Henry

2009-03-01

In recent years chaotic secure communication and chaos synchronization have received ever increasing attention. In this paper, for the first time, a fractional chaotic communication method using an extended fractional Kalman filter is presented. The chaotic synchronization is implemented by the EFKF design in the presence of channel additive noise and processing noise. Encoding chaotic communication achieves a satisfactory, typical secure communication scheme. In the proposed system, security is enhanced based on spreading the signal in frequency and encrypting it in time domain. In this paper, the main advantages of using fractional order systems, increasing nonlinearity and spreading the power spectrum are highlighted. To illustrate the effectiveness of the proposed scheme, a numerical example based on the fractional Lorenz dynamical system is presented and the results are compared to the integer Lorenz system.

VLSI Implementation of a 2.8 Gevent/s Packet-Based AER Interface with Routing and Event Sorting Functionality

PubMed Central

Scholze, Stefan; Schiefer, Stefan; Partzsch, Johannes; Hartmann, Stephan; Mayr, Christian Georg; Höppner, Sebastian; Eisenreich, Holger; Henker, Stephan; Vogginger, Bernhard; Schüffny, Rene

2011-01-01

State-of-the-art large-scale neuromorphic systems require sophisticated spike event communication between units of the neural network. We present a high-speed communication infrastructure for a waferscale neuromorphic system, based on application-specific neuromorphic communication ICs in an field programmable gate arrays (FPGA)-maintained environment. The ICs implement configurable axonal delays, as required for certain types of dynamic processing or for emulating spike-based learning among distant cortical areas. Measurements are presented which show the efficacy of these delays in influencing behavior of neuromorphic benchmarks. The specialized, dedicated address-event-representation communication in most current systems requires separate, low-bandwidth configuration channels. In contrast, the configuration of the waferscale neuromorphic system is also handled by the digital packet-based pulse channel, which transmits configuration data at the full bandwidth otherwise used for pulse transmission. The overall so-called pulse communication subgroup (ICs and FPGA) delivers a factor 25–50 more event transmission rate than other current neuromorphic communication infrastructures. PMID:22016720

49 CFR 1242.79 - Communication systems operations (account XX-55-77).

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 9 2010-10-01 2010-10-01 false Communication systems operations (account XX-55-77...-Transportation § 1242.79 Communication systems operations (account XX-55-77). Separate common expenses on bases of the percentages calculated for the separation of Communication Systems (account XX-19-20), § 1242...

Nonlinear filter based decision feedback equalizer for optical communication systems.

PubMed

Han, Xiaoqi; Cheng, Chi-Hao

2014-04-07

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.

Design of oil pipeline leak detection and communication system based on optical fiber technology

NASA Astrophysics Data System (ADS)

Tu, Yaqing; Chen, Huabo

1999-08-01

The integrity of oil pipeline is always a major concern of operators. Pipeline leak not only leads to loss of oil, but pollutes environment. A new pipeline leak detection and communication system based on optical fiber technology to ensure the pipeline reliability is presented. Combined direct leak detection method with an indirect one, the system will greatly reduce the rate of false alarm. According, to the practical features of oil pipeline,the pipeline communication system is designed employing the state-of-the-art optic fiber communication technology. The system has such feature as high location accuracy of leak detection, good real-time characteristic, etc. which overcomes the disadvantages of traditional leak detection methods and communication system effectively.

Advanced Approach of Multiagent Based Buoy Communication

PubMed Central

Gricius, Gediminas; Drungilas, Darius; Dzemydiene, Dale

2015-01-01

Usually, a hydrometeorological information system is faced with great data flows, but the data levels are often excessive, depending on the observed region of the water. The paper presents advanced buoy communication technologies based on multiagent interaction and data exchange between several monitoring system nodes. The proposed management of buoy communication is based on a clustering algorithm, which enables the performance of the hydrometeorological information system to be enhanced. The experiment is based on the design and analysis of the inexpensive but reliable Baltic Sea autonomous monitoring network (buoys), which would be able to continuously monitor and collect temperature, waviness, and other required data. The proposed approach of multiagent based buoy communication enables all the data from the costal-based station to be monitored with limited transition speed by setting different tasks for the agent-based buoy system according to the clustering information. PMID:26345197

System Models of Information, Communication and Mass Communication: Revaluation of Some Basic Concepts of Communication.

ERIC Educational Resources Information Center

Wiio, Osmo A.

A more unified approach to communication theory can evolve through systems modeling of information theory, communication modes, and mass media operations. Such systematic analysis proposes, as is the case care here, that information models be based upon combinations of energy changes and exchanges and changes in receiver systems. The mass media is…

Performance analysis of fiber-based free-space optical communications with coherent detection spatial diversity.

PubMed

Li, Kangning; Ma, Jing; Tan, Liying; Yu, Siyuan; Zhai, Chao

2016-06-10

The performances of fiber-based free-space optical (FSO) communications over gamma-gamma distributed turbulence are studied for multiple aperture receiver systems. The equal gain combining (EGC) technique is considered as a practical scheme to mitigate the atmospheric turbulence. Bit error rate (BER) performances for binary-phase-shift-keying-modulated coherent detection fiber-based free-space optical communications are derived and analyzed for EGC diversity receptions through an approximation method. To show the net diversity gain of a multiple aperture receiver system, BER performances of EGC are compared with a single monolithic aperture receiver system with the same total aperture area (same average total incident optical power on the aperture surface) for fiber-based free-space optical communications. The analytical results are verified by Monte Carlo simulations. System performances are also compared for EGC diversity coherent FSO communications with or without considering fiber-coupling efficiencies.

Free-space laser communication system with rapid acquisition based on astronomical telescopes.

PubMed

Wang, Jianmin; Lv, Junyi; Zhao, Guang; Wang, Gang

2015-08-10

The general structure of a free-space optical (FSO) communication system based on astronomical telescopes is proposed. The light path for astronomical observation and for communication can be easily switched. A separate camera is used as a star sensor to determine the pointing direction of the optical terminal's antenna. The new system exhibits rapid acquisition and is widely applicable in various astronomical telescope systems and wavelengths. We present a detailed analysis of the acquisition time, which can be decreased by one order of magnitude compared with traditional optical communication systems. Furthermore, we verify software algorithms and tracking accuracy.

Designing an IMAC system using TeraNet

NASA Astrophysics Data System (ADS)

Mun, In K.; Hilal, S. K.; Andrews, M. C.; Gidron, Rafael

1992-07-01

Even though considerable progresses have been made with communication technology, one of the more difficult problems facing in installing a comprehensive clinically effective Image Management and Communication (IMAC) system for a hospital is the communication problem. Most existing systems are based on Ethernet or Token-ring net. Some of the newer systems are being installed using FDDL. All these systems have inherent problems like communication speed, control of bandwidth usage, or/and poor performance under heavy traffic. In order to overcome these difficulties, we are designing a complete IMAC system based on a novel network known as TeraNet, being developed at Center for Telecommunication Research, Columbia University.

Effect of the incidence angle to free space optical communication based on cat-eye modulating retro-reflector

NASA Astrophysics Data System (ADS)

Zhang, Lai-xian; Sun, Hua-yan; Zhao, Yan-zhong; Zheng, Yong-hui; Shan, Cong-miao

2013-08-01

Based on the cat-eye effect of optical system, free space optical communication based on cat-eye modulating retro-reflector can build communication link rapidly. Compared to classical free space optical communication system, system based on cat-eye modulating retro-reflector has great advantages such as building communication link more rapidly, a passive terminal is smaller, lighter and lower power consuming. The incident angle is an important factor of cat-eye effect, so it will affect the retro-reflecting communication link. In this paper, the principle and work flow of free space optical communication based on cat-eye modulating retro-reflector were introduced. Then, using the theory of geometric optics, the equivalent model of modulating retro-reflector with incidence angle was presented. The analytical solution of active area and retro-reflected light intensity of cat-eye modulating retro-reflector were given. Noise of PIN photodetector was analyzed, based on which, bit error rate of free space optical communication based on cat-eye modulating retro-reflector was presented. Finally, simulations were done to study the effect of incidence angle to the communication. The simulation results show that the incidence angle has little effect on active area and retro-reflected light intensity when the incidence beam is in the active field angle of cat-eye modulating retro-reflector. With certain system and condition, the communication link can rapidly be built when the incidence light beam is in the field angle, and the bit error rate increases greatly with link range. When link range is smaller than 35Km, the bit error rate is less than 10-16.

[Design and realization of the communication system for the mobile medical terminal].

PubMed

Ji, Lei; Guo, Xu; Shi, Huayu

2013-01-01

Realizing wireless communication based on handset devices for medical staff; providing an instant messaging method. Constructing a set of communication protocols and standards; developing software both on server and client. Building an instant messaging system which follows the customized specification; based on Android the client provides functions like address book, message, voice service etc. As an independent module of the mobile medical terminal, the system can provide convenient communication for medical service with other mobile business.

Classical noise, quantum noise and secure communication

NASA Astrophysics Data System (ADS)

Tannous, C.; Langlois, J.

2016-01-01

Secure communication based on message encryption might be performed by combining the message with controlled noise (called pseudo-noise) as performed in spread-spectrum communication used presently in Wi-Fi and smartphone telecommunication systems. Quantum communication based on entanglement is another route for securing communications as demonstrated by several important experiments described in this work. The central role played by the photon in unifying the description of classical and quantum noise as major ingredients of secure communication systems is highlighted and described on the basis of the classical and quantum fluctuation dissipation theorems.

Compound synchronization of four memristor chaotic oscillator systems and secure communication.

PubMed

Sun, Junwei; Shen, Yi; Yin, Quan; Xu, Chengjie

2013-03-01

In this paper, a novel kind of compound synchronization among four chaotic systems is investigated, where the drive systems have been conceptually divided into two categories: scaling drive systems and base drive systems. Firstly, a sufficient condition is obtained to ensure compound synchronization among four memristor chaotic oscillator systems based on the adaptive technique. Secondly, a secure communication scheme via adaptive compound synchronization of four memristor chaotic oscillator systems is presented. The corresponding theoretical proofs and numerical simulations are given to demonstrate the validity and feasibility of the proposed control technique. The unpredictability of scaling drive systems can additionally enhance the security of communication. The transmitted signals can be split into several parts loaded in the drive systems to improve the reliability of communication.

A vision of network-centric military communications

NASA Astrophysics Data System (ADS)

Conklin, Ross, Jr.; Burbank, Jack; Nichols, Robert, Jr.

2005-05-01

This paper presents a vision for a future capability-based military communications system that considers user requirements. Historically, the military has developed and fielded many specialized communications systems. While these systems solved immediate communications problems, they were not designed to operate with other systems. As information has become more important to the execution of war, the "stove-pipe" nature of the communications systems deployed by the military is no longer acceptable. Realizing this, the military has begun the transformation of communications to a network-centric communications paradigm. However, the specialized communications systems were developed in response to the widely varying environments related to military communications. These environments, and the necessity for effective communications within these environments, do not disappear under the network-centric paradigm. In fact, network-centric communications allows for one message to cross many of these environments by transiting multiple networks. The military would also like one communications approach that is capable of working well in multiple environments. This paper presents preliminary work on the creation of a framework that allows for a reconfigurable device that is capable of adapting to the physical and network environments. The framework returns to the Open Systems Interconnect (OSI) architecture with the addition of a standardized intra-layer control interface for control information exchange, a standardized data interface and a proposed device architecture based on the software radio.

Data-Base for Communication Planning. The Basic and Statistical Data Required for the Elaboration of a Plan for a National Communication System.

ERIC Educational Resources Information Center

Rahim, Syed A.

Based in part on a list developed by the United Nations Educational, Scientific, and Cultural Organization (UNESCO) for use in Afghanistan, this document presents a comprehensive checklist of items of statistical and descriptive data required for planning a national communication system. It is noted that such a system provides the vital…

Realization of PLC to the Variable Frequency Speed Regulation System of Mine Local Ventilator based on RS-485 Communication

NASA Astrophysics Data System (ADS)

Ma, Kai; Li, Jian; Yun, Yichong

2018-03-01

The article first introduces the merits of serial communication in the PLC to the variable frequency speed regulation system of mine local ventilator, and then sets up a hardware application development platform of PLC and inverter based on RS-485 communication technology, next presents communication initialization of the PLC and Inverter. Finally according to the control requirements, PLC send run operation & monitoring instruction to Inverter, realizes the serial communication control between the PLC and Inverter.

Transceiver for Space Station Freedom

NASA Technical Reports Server (NTRS)

Fitzmaurice, M.; Bruno, R.

1990-01-01

This paper describes the design of the Laser Communication Transceiver (LCT) system which was planned to be flight tested as an attached payload on Space Station Freedom. The objective in building and flight-testing the LCT is to perform a broad class of tests addressing the critical aspects of space-based optical communications systems, providing a base of experience for applying laser communications technology toward future communications needs. The LCT's functional and performance requirements and capabilities with respect to acquisition, spatial tracking and pointing, communications, and attitude determination are discussed.

Transceiver for Space Station Freedom

NASA Astrophysics Data System (ADS)

Fitzmaurice, M.; Bruno, R.

1990-07-01

This paper describes the design of the Laser Communication Transceiver (LCT) system which was planned to be flight tested as an attached payload on Space Station Freedom. The objective in building and flight-testing the LCT is to perform a broad class of tests addressing the critical aspects of space-based optical communications systems, providing a base of experience for applying laser communications technology toward future communications needs. The LCT's functional and performance requirements and capabilities with respect to acquisition, spatial tracking and pointing, communications, and attitude determination are discussed.

An Experimental Study of a Micro-Projection Enabled Optical Terminal for Short-Range Bidirectional Multi-Wavelength Visible Light Communications

PubMed Central

Tsai, Cheng-Yu; Jiang, Jhih-Shan

2018-01-01

A micro-projection enabled short-range communication (SRC) approach using red-, green- and blue-based light-emitting diodes (RGB-LEDs) has experimentally demonstrated recently that micro-projection and high-speed data transmission can be performed simultaneously. In this research, a reconfigurable design of a polarization modulated image system based on the use of a Liquid Crystal on Silicon based Spatial Light Modulator (LCoS-based SLM) serving as a portable optical terminal capable of micro-projection and bidirectional multi-wavelength communications is proposed and experimentally demonstrated. For the proof of concept, the system performance was evaluated through a bidirectional communication link at a transmission distance over 0.65 m. In order to make the proposed communication system architecture compatible with the data modulation format of future possible wireless communication system, baseband modulation scheme, i.e., Non-Return-to-Zero On-Off-Keying (NRZ_OOK), M-ary Phase Shift Keying (M-PSK) and M-ary Quadrature Amplitude Modulation (M-QAM) were used to investigate the system transmission performance. The experimental results shown that an acceptable BER (satisfying the limitation of Forward Error Correction, FEC standard) and crosstalk can all be achieved in the bidirectional multi-wavelength communication scenario. PMID:29587457

Relating Communications Mode Choice and Teamwork Quality: Conversational versus Textual Communication in IT System and Software Development Teams

ERIC Educational Resources Information Center

Smith, James Robert

2012-01-01

This cross-sectional study explored how IT system and software development team members communicated in the workplace and whether teams that used more verbal communication (and less text-based communication) experienced higher levels of collaboration as measured using the Teamwork Quality (TWQ) scale. Although computer-mediated communication tools…

Roadside-based communication system and method

NASA Technical Reports Server (NTRS)

Bachelder, Aaron D. (Inventor)

2007-01-01

A roadside-based communication system providing backup communication between emergency mobile units and emergency command centers. In the event of failure of a primary communication, the mobile units transmit wireless messages to nearby roadside controllers that may take the form of intersection controllers. The intersection controllers receive the wireless messages, convert the messages into standard digital streams, and transmit the digital streams along a citywide network to a destination intersection or command center.

A Cross-Lingual Mobile Medical Communication System Prototype for Foreigners and Subjects with Speech, Hearing, and Mental Disabilities Based on Pictograms

PubMed Central

Wołk, Agnieszka; Glinkowski, Wojciech

2017-01-01

People with speech, hearing, or mental impairment require special communication assistance, especially for medical purposes. Automatic solutions for speech recognition and voice synthesis from text are poor fits for communication in the medical domain because they are dependent on error-prone statistical models. Systems dependent on manual text input are insufficient. Recently introduced systems for automatic sign language recognition are dependent on statistical models as well as on image and gesture quality. Such systems remain in early development and are based mostly on minimal hand gestures unsuitable for medical purposes. Furthermore, solutions that rely on the Internet cannot be used after disasters that require humanitarian aid. We propose a high-speed, intuitive, Internet-free, voice-free, and text-free tool suited for emergency medical communication. Our solution is a pictogram-based application that provides easy communication for individuals who have speech or hearing impairment or mental health issues that impair communication, as well as foreigners who do not speak the local language. It provides support and clarification in communication by using intuitive icons and interactive symbols that are easy to use on a mobile device. Such pictogram-based communication can be quite effective and ultimately make people's lives happier, easier, and safer. PMID:29230254

A Cross-Lingual Mobile Medical Communication System Prototype for Foreigners and Subjects with Speech, Hearing, and Mental Disabilities Based on Pictograms.

PubMed

Wołk, Krzysztof; Wołk, Agnieszka; Glinkowski, Wojciech

2017-01-01

People with speech, hearing, or mental impairment require special communication assistance, especially for medical purposes. Automatic solutions for speech recognition and voice synthesis from text are poor fits for communication in the medical domain because they are dependent on error-prone statistical models. Systems dependent on manual text input are insufficient. Recently introduced systems for automatic sign language recognition are dependent on statistical models as well as on image and gesture quality. Such systems remain in early development and are based mostly on minimal hand gestures unsuitable for medical purposes. Furthermore, solutions that rely on the Internet cannot be used after disasters that require humanitarian aid. We propose a high-speed, intuitive, Internet-free, voice-free, and text-free tool suited for emergency medical communication. Our solution is a pictogram-based application that provides easy communication for individuals who have speech or hearing impairment or mental health issues that impair communication, as well as foreigners who do not speak the local language. It provides support and clarification in communication by using intuitive icons and interactive symbols that are easy to use on a mobile device. Such pictogram-based communication can be quite effective and ultimately make people's lives happier, easier, and safer.

Secure communications of CAP-4 and OOK signals over MMF based on electro-optic chaos.

PubMed

Ai, Jianzhou; Wang, Lulu; Wang, Jian

2017-09-15

Chaos-based secure communication can provide a high level of privacy in data transmission. Here, we experimentally demonstrate secure signal transmission over two kinds of multimode fiber (MMF) based on electro-optic intensity chaos. High-quality synchronization is achieved in an electro-optic feedback configuration. Both 5  Gbit/s carrier-less amplitude/phase (CAP-4) modulation and 10  Gbit/s on-off key (OOK) signals are recovered efficiently in electro-optic chaos-based communication systems. Degradations of chaos synchronization and communication system due to mismatch of various hardware keys are also discussed.

Secure electronic commerce communication system based on CA

NASA Astrophysics Data System (ADS)

Chen, Deyun; Zhang, Junfeng; Pei, Shujun

2001-07-01

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.

CPP-TRS(C): On using visual cognitive symbols to enhance communication effectiveness

NASA Technical Reports Server (NTRS)

Tonfoni, Graziella

1994-01-01

Communicative Positioning Program/Text Representation Systems (CPP-TRS) is a visual language based on a system of 12 canvasses, 10 signals and 14 symbols. CPP-TRS is based on the fact that every communication action is the result of a set of cognitive processes and the whole system is based on the concept that you can enhance communication by visually perceiving text. With a simple syntax, CPP-TRS is capable of representing meaning and intention as well as communication functions visually. Those are precisely invisible aspects of natural language that are most relevant to getting the global meaning of a text. CPP-TRS reinforces natural language in human machine interaction systems. It complements natural language by adding certain important elements that are not represented by natural language by itself. These include communication intention and function of the text expressed by the sender, as well as the role the reader is supposed to play. The communication intention and function of a text and the reader's role are invisible in natural language because neither specific words nor punctuation conveys them sufficiently and unambiguously; they are therefore non-transparent.

Vision communications based on LED array and imaging sensor

NASA Astrophysics Data System (ADS)

Yoo, Jong-Ho; Jung, Sung-Yoon

2012-11-01

In this paper, we propose a brand new communication concept, called as "vision communication" based on LED array and image sensor. This system consists of LED array as a transmitter and digital device which include image sensor such as CCD and CMOS as receiver. In order to transmit data, the proposed communication scheme simultaneously uses the digital image processing and optical wireless communication scheme. Therefore, the cognitive communication scheme is possible with the help of recognition techniques used in vision system. By increasing data rate, our scheme can use LED array consisting of several multi-spectral LEDs. Because arranged each LED can emit multi-spectral optical signal such as visible, infrared and ultraviolet light, the increase of data rate is possible similar to WDM and MIMO skills used in traditional optical and wireless communications. In addition, this multi-spectral capability also makes it possible to avoid the optical noises in communication environment. In our vision communication scheme, the data packet is composed of Sync. data and information data. Sync. data is used to detect the transmitter area and calibrate the distorted image snapshots obtained by image sensor. By making the optical rate of LED array be same with the frame rate (frames per second) of image sensor, we can decode the information data included in each image snapshot based on image processing and optical wireless communication techniques. Through experiment based on practical test bed system, we confirm the feasibility of the proposed vision communications based on LED array and image sensor.

Performance Investigation of FSO-OFDM Communication Systems under the Heavy Rain Weather

NASA Astrophysics Data System (ADS)

Rashidi, Florence; He, Jing; Chen, Lin

2017-12-01

The challenge in the free-space optical (FSO) communication is the propagation of optical signal through different atmospheric conditions such as rain, snow and fog. In this paper, an orthogonal frequency-division multiplexing technique (OFDM) is proposed in the FSO communication system. Meanwhile, considering the rain attenuation models based on Marshal & Palmer and Carbonneau models, the performance of FSO communication system based on the OFDM is evaluated under the heavy-rain condition in Changsha, China. The simulation results show that, under a heavy-rainfall condition of 106.18 mm/h, with an attenuation factor of 7 dB/km based on the Marshal & Palmer model, the bit rate of 2.5 and 4.0 Gbps data can be transmitted over the FSO channels of 1.6 and 1.3 km, respectively, and the bit error rate of less than 1E - 4 can be achieved. In addition, the effect on rain attenuation over the FSO communication system based on the Marshal & Palmer model is less than that of the Carbonneau model.

Communications Based Train Control (CBTC) Before and After Cost Study

DOT National Transportation Integrated Search

2011-03-01

San Francisco Municipal Railway (Muni) undertook a retrofit of a fixed-block signaling system with a communications-based train control (CBTC) system in the subway portion of their light rail system (Muni Metro subway) in 1998. This report presents t...

Characterization Test Procedures for Intersection Collision Avoidance Systems Based on Vehicle-to-Vehicle Communications

DOT National Transportation Integrated Search

2015-12-01

Characterization test procedures have been developed to quantify the performance of intersection collision avoidance (ICA) systems based on vehicle-to-vehicle communications. These systems warn the driver of an imminent crossing-path collision at a r...

In-House Communication Support System Based on the Information Propagation Model Utilizes Social Network

NASA Astrophysics Data System (ADS)

Takeuchi, Susumu; Teranishi, Yuuichi; Harumoto, Kaname; Shimojo, Shinji

Almost all companies are now utilizing computer networks to support speedier and more effective in-house information-sharing and communication. However, existing systems are designed to support communications only within the same department. Therefore, in our research, we propose an in-house communication support system which is based on the “Information Propagation Model (IPM).” The IPM is proposed to realize word-of-mouth communication in a social network, and to support information-sharing on the network. By applying the system in a real company, we found that information could be exchanged between different and unrelated departments, and such exchanges of information could help to build new relationships between the users who are apart on the social network.

Space-Based Optical Communications with CubeSats

NASA Technical Reports Server (NTRS)

Ebert, Monica L.; Nguyen, Anh Ngoc; Frost, Chad

2017-01-01

Optical communication systems use lasers to encode and transmit data with higher speed and density than traditional radio frequency (RF)-based communications. Smaller antennas, lower power requirements, and increased spectrum availability enable optical communications to be integrated into CubeSats more easily than radios, enabling afford-able communications solutions for future NASA missions.

Development of a HTS transceiver sub-system for 3G mobile communication TD-SCDMA base station

NASA Astrophysics Data System (ADS)

Zhang, Xueqiang; He, Xiaofeng; Wang, Yuehui; Duan, Tao; Wang, Guizhen; Zhang, Yan; Li, Chunguang; Zhang, Qiang; Li, Hong; He, Yusheng

2010-02-01

A prototype of a high temperature superconducting (HTS) transceiver sub-system for applications in a TD-SCDMA, one of the third generation (3G) communication standards, base station has been developed. Both the HTS sub-system and the conventional counterpart have been implemented into a TD-SCDMA commercial communication network and comparison test studies were carried out. The measured results showed that the HTS sub-system could remarkably improve the RF performance of both transmitting and receiving chains.

A cost-effective traffic data collection system based on the iDEN mobile telecommunication network.

DOT National Transportation Integrated Search

2008-10-01

This report describes a cost-effective data collection system for Caltrans 170 traffic signal : controller. The data collection system is based on TCP/IP communication over existing : low-cost mobile communication networks and Motorola iDEN1 mobile...

A design proposal of a certain missile tactical command system based on Beidou satellite communication and GPS positioning techniques

NASA Astrophysics Data System (ADS)

Ma, Jian; Hao, Yongsheng; Miao, Jian; Zhang, Jianmao

2007-11-01

This paper introduced a design proposal of tactical command system that applied to a kind of anti-tank missile carriers. The tactical command system was made up of embedded computer system based on PC104 bus, Linux operating system, digital military map, Beidou satellite communication equipments and GPS positioning equipments. The geographic coordinates was measured by the GPS receiver, the positioning data, commands and information were transmitted real-time between tactical command systems, tactical command systems and command center, by the Beidou satellite communication systems. The Beidou satellite communication equipments and GPS positioning equipments were integrated to an independent module, exchanging data with embedded computer through RS232 serial ports and USB ports. The decision support system software based on information fusion, calculates positioning data, geography information and battle field information synthetically, shows the position of allies and the position of enemy on the military map, and assesses the various threats of different enemy objects, educes a situation assessment and threat assessment.

Airborne space laser communication system and experiments

NASA Astrophysics Data System (ADS)

Li, Xiao-Ming; Zhang, Li-zhong; Meng, Li-Xin

2015-11-01

Airborne space laser communication is characterized by its high speed, anti-electromagnetic interference, security, easy to assign. It has broad application in the areas of integrated space-ground communication networking, military communication, anti-electromagnetic communication. This paper introduce the component and APT system of the airborne laser communication system design by Changchun university of science and technology base on characteristic of airborne laser communication and Y12 plan, especially introduce the high communication speed and long distance communication experiment of the system that among two Y12 plans. In the experiment got the aim that the max communication distance 144Km, error 10-6 2.5Gbps - 10-7 1.5Gbps capture probability 97%, average capture time 20s. The experiment proving the adaptability of the APT and the high speed long distance communication.

Comparing Acquisition of Exchange-Based and Signed Mands with Children with Autism

ERIC Educational Resources Information Center

Barlow, Kathryn E.; Tiger, Jeffrey H.; Slocum, Sarah K.; Miller, Sarah J.

2013-01-01

Therapists and educators frequently teach alternative-communication systems, such as picture exchanges or manual signs, to individuals with developmental disabilities who present with expressive language deficits. Michael (1985) recommended a taxonomy for alternative communication systems that differentiated between selection-based systems in…

What Communication Theories Can Teach the Designer of Computer-Based Training.

ERIC Educational Resources Information Center

Larsen, Ronald E.

1985-01-01

Reviews characteristics of computer-based training (CBT) that make application of communication theories appropriate and presents principles from communication theory (e.g., general systems theory, symbolic interactionism, rule theories, and interpersonal communication theories) to illustrate how CBT developers can profitably apply them to…

Digital, Satellite-Based Aeronautical Communication

NASA Technical Reports Server (NTRS)

Davarian, F.

1989-01-01

Satellite system relays communication between aircraft and stations on ground. System offers better coverage with direct communication between air and ground, costs less and makes possible new communication services. Carries both voice and data. Because many data exchanged between aircraft and ground contain safety-related information, probability of bit errors essential.

Generalization of a pictorial alternative communication system across instructors and distance.

PubMed

Ganz, Jennifer B; Sigafoos, Jeff; Simpson, Richard L; Cook, Katherine E

2008-01-01

Nonverbal individuals with autism spectrum disorders (ASD) often require the use of picture-based, aided augmentative and alternative communication (AAC) systems. Such systems are used widely, but little research has investigated the generalization of these devices to a variety of communicative partners and under a variety of conditions. We investigated use of a modified Picture Exchange Communication System (PECS) protocol to teach AAC-supported functional communication skills to a 12-year-old boy with autism. Results indicate that the participant was able to generalize his communication skills across a variety of instructors and to use functional non-verbal strategies to respond to communication obstacles.

Display-based communications for advanced transport aircraft

NASA Technical Reports Server (NTRS)

Lee, Alfred T.

1989-01-01

The next generation of civil transport aircraft will depend increasingly upon ground-air-ground and satellite data link for information critical to safe and efficient air transportation. Previous studies which examined the concept of display-based communications in addition to, or in lieu of, conventional voice transmissions are reviewed. A full-mission flight simulation comparing voice and display-based communication modes in an advanced transport aircraft is also described. The results indicate that a display-based mode of information transfer does not result in significantly increased aircrew workload, but does result in substantially increased message acknowledgment times when compared to conventional voice transmissions. User acceptance of the display-based communication system was generally high, replicating the findings of previous studies. However, most pilots tested expressed concern over the potential loss of information available from frequency monitoring which might result from the introduction of discrete address communications. Concern was expressed by some pilots for the reduced time available to search for conflicting traffic when using the communications display system. The implications of the findings for the design of display-based communications are discussed.

Analysis of CPolSK-based FSO system working in space-to-ground channel

NASA Astrophysics Data System (ADS)

Su, Yuwei; Sato, Takuro

2018-03-01

In this article, the transmission performance of a circle polarization shift keying (CPolSK)-based free space optical (FSO) system working in space-to-ground channel is analyzed. Formulas describing the optical polarization distortion caused by the atmospheric turbulence and the communication qualities in terms of signal-to-noise-ratio (SNR), bit-error-ratio (BER) and outage probability of the proposed system are derived. Based on the Stokes parameters data measured by a Japanese optical communication satellite, we evaluate the space-to-ground FSO link and simulate the system performance under a varying regime of turbulence strength. The proposed system provides a more efficient way to compensate scintillation effects in a comparison with the on-off-keying (OOK)-based FSO system. These results are useful to the designing and evaluating of a deep space FSO communication system.

Research of home energy management system based on technology of PLC and ZigBee

NASA Astrophysics Data System (ADS)

Wei, Qi; Shen, Jiaojiao

2015-12-01

In view of the problem of saving effectively energy and energy management in home, this paper designs a home energy intelligent control system based on power line carrier communication and wireless ZigBee sensor networks. The system is based on ARM controller, power line carrier communication and wireless ZigBee sensor network as the terminal communication mode, and realizes the centralized and intelligent control of home appliances. Through the combination of these two technologies, the advantages of the two technologies complement each other, and provide a feasible plan for the construction of energy-efficient, intelligent home energy management system.

Interactive educational technologies as a method of communicative competency development of optical and fiber optic communication systems specialists

NASA Astrophysics Data System (ADS)

Matveeva, Tatiana U.; Osadchiy, Igor S.; Husnutdinova, Marina N.

2017-04-01

The article examines the process of formation of communicative competencies of optic and fiber optic communication systems specialists; the role of communicative competencies is examined in the structure of professionally important skills, together with the contents of professional activity. The stages of empirical research into formation of communicative competencies have been presented, and the values of statistical reliability of data have been provided. The model of formation of communicative competency using interactive technology has been developed based on the research done, and main stages of model implementation and motives of formation of communicative competency have been highlighted. A scheme of "Communicative competence as a base of future success" training session has been suggested as one of the basic interactive technologies. Main components of education that are used during the stages of the training cycle have been examined. The statistical data on the effectiveness of use of interactive educational technologies has been presented; it allowed development of communicative competency of specialists in the field of optical and fiber optic communication system.

Application of AirCell Cellular AMPS Network and Iridium Satellite System Dual Mode Service to Air Traffic Management

NASA Technical Reports Server (NTRS)

Shamma, Mohammed A.

2004-01-01

The AirCell/Iridium dual mode service is evaluated for potential applications to Air Traffic Management (ATM) communication needs. The AirCell system which is largely based on the Advanced Mobile Phone System (AMPS) technology, and the Iridium FDMA/TDMA system largely based on the Global System for Mobile Communications(GSM) technology, can both provide communication relief for existing or future aeronautical communication links. Both have a potential to serve as experimental platforms for future technologies via a cost effective approach. The two systems are well established in the entire CONUS and globally hence making it feasible to utilize in all regions, for all altitudes, and all classes of aircraft. Both systems have been certified for air usage. The paper summarizes the specifications of the AirCell/Iridium system, as well as the ATM current and future links, and application specifications. the paper highlights the scenarios, applications, and conditions under which the AirCell/Iridium technology can be suited for ATM Communication.

Communication and Gamification in the Web-Based Foreign Language Educational System: Web- Based Foreign Language Educational System

ERIC Educational Resources Information Center

Osipov, Ilya V.; Volinsky, Alex A.; Nikulchev, Evgeny; Prasikova, Anna Y.

2016-01-01

The paper describes development of the educational online web communication platform for teaching and learning foreign languages. The main objective was to develop a web application for teaching foreigners to understand casual fluent speech. The system is based on the time bank principle, allowing users to teach others their native language along…

Challenge Study: A Project-Based Learning on a Wireless Communication System at Technical High School

ERIC Educational Resources Information Center

Terasawa, Ikuo

2016-01-01

The challenge study is a project based learning curriculum at Technical High School aimed at the construction of a wireless communication system. The first period was engineering issues in the construction of an artificial satellite and the second period was a positional locating system based on the general purpose wire-less device--ZigBee device.…

Addressing Electronic Communications System Learning through a Radar-Based Active Learning Project

ERIC Educational Resources Information Center

Hernandez-Jayo, Unai; López-Garde, Juan-Manuel; Rodríguez-Seco, J. Emilio

2015-01-01

In the Master's of Telecommunication Engineering program at the University of Deusto, Spain, courses in communication circuit design, electronic instrumentation, advanced systems for signal processing and radiocommunication systems allow students to acquire concepts crucial to the fields of electronics and communication. During the educational…

Response to a Community-Based Information and Communication System.

ERIC Educational Resources Information Center

Trachtman, Leon E.; And Others

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…

Enhancing performance of next generation FSO communication systems using soft computing-based predictions.

PubMed

Kazaura, Kamugisha; Omae, Kazunori; Suzuki, Toshiji; Matsumoto, Mitsuji; Mutafungwa, Edward; Korhonen, Timo O; Murakami, Tadaaki; Takahashi, Koichi; Matsumoto, Hideki; Wakamori, Kazuhiko; Arimoto, Yoshinori

2006-06-12

The deterioration and deformation of a free-space optical beam wave-front as it propagates through the atmosphere can reduce the link availability and may introduce burst errors thus degrading the performance of the system. We investigate the suitability of utilizing soft-computing (SC) based tools for improving performance of free-space optical (FSO) communications systems. The SC based tools are used for the prediction of key parameters of a FSO communications system. Measured data collected from an experimental FSO communication system is used as training and testing data for a proposed multi-layer neural network predictor (MNNP) used to predict future parameter values. The predicted parameters are essential for reducing transmission errors by improving the antenna's accuracy of tracking data beams. This is particularly essential for periods considered to be of strong atmospheric turbulence. The parameter values predicted using the proposed tool show acceptable conformity with original measurements.

Mathematical modeling and measurement of electric fields of electrode-based through-the-earth (TTE) communication

NASA Astrophysics Data System (ADS)

Yan, Lincan; Zhou, Chenming; Reyes, Miguel; Whisner, Bruce; Damiano, Nicholas

2017-06-01

There are two types of through-the-earth (TTE) wireless communication in the mining industry: magnetic loop TTE and electrode-based (or linear) TTE. While the magnetic loop systems send signal through magnetic fields, the transmitter of an electrode-based TTE system sends signal directly through the mine overburden by driving an extremely low frequency (ELF) or ultralow frequency (ULF) AC current into the earth. The receiver at the other end (underground or surface) detects the resultant current and receives it as a voltage. A wireless communication link between surface and underground is then established. For electrode-based TTE communications, the signal is transmitted through the established electric field and is received as a voltage detected at the receiver. It is important to understand the electric field distribution within the mine overburden for the purpose of designing and improving the performance of the electrode-based TTE systems. In this paper, a complete explicit solution for all three electric field components for the electrode-based TTE communication was developed. An experiment was conducted using a prototype electrode-based TTE system developed by National Institute for Occupational Safety and Health. The mathematical model was then compared and validated with test data. A reasonable agreement was found between them.

Mathematical modeling and measurement of electric fields of electrode-based through-the-earth (TTE) communication.

PubMed

Yan, Lincan; Zhou, Chenming; Reyes, Miguel; Whisner, Bruce; Damiano, Nicholas

2017-07-12

There are two types of through-the-earth (TTE) wireless communication in the mining industry: magnetic loop TTE and electrode-based (or linear) TTE. While the magnetic loop systems send signal through magnetic fields, the transmitter of an electrode-based TTE system sends signal directly through the mine overburden by driving an extremely low frequency (ELF) or ultralow frequency (ULF) AC current into the earth. The receiver at the other end (underground or surface) detects the resultant current and receives it as a voltage. A wireless communication link between surface and underground is then established. For electrode-based TTE communications, the signal is transmitted through the established electric field and is received as a voltage detected at the receiver. It is important to understand the electric field distribution within the mine overburden for the purpose of designing and improving the performance of the electrode-based TTE systems. In this paper, a complete explicit solution for all three electric field components for the electrode-based TTE communication was developed. An experiment was conducted using a prototype electrode-based TTE system developed by National Institute for Occupational Safety and Health. The mathematical model was then compared and validated with test data. A reasonable agreement was found between them.

Mathematical modeling and measurement of electric fields of electrode-based through-the-earth (TTE) communication

PubMed Central

Yan, Lincan; Zhou, Chenming; Reyes, Miguel; Whisner, Bruce; Damiano, Nicholas

2017-01-01

There are two types of through-the-earth (TTE) wireless communication in the mining industry: magnetic loop TTE and electrode-based (or linear) TTE. While the magnetic loop systems send signal through magnetic fields, the transmitter of an electrode-based TTE system sends signal directly through the mine overburden by driving an extremely low frequency (ELF) or ultralow frequency (ULF) AC current into the earth. The receiver at the other end (underground or surface) detects the resultant current and receives it as a voltage. A wireless communication link between surface and underground is then established. For electrode-based TTE communications, the signal is transmitted through the established electric field and is received as a voltage detected at the receiver. It is important to understand the electric field distribution within the mine overburden for the purpose of designing and improving the performance of the electrode-based TTE systems. In this paper, a complete explicit solution for all three electric field components for the electrode-based TTE communication was developed. An experiment was conducted using a prototype electrode-based TTE system developed by National Institute for Occupational Safety and Health. The mathematical model was then compared and validated with test data. A reasonable agreement was found between them. PMID:28845062

Computation and Communication Evaluation of an Authentication Mechanism for Time-Triggered Networked Control Systems

PubMed Central

Martins, Goncalo; Moondra, Arul; Dubey, Abhishek; Bhattacharjee, Anirban; Koutsoukos, Xenofon D.

2016-01-01

In modern networked control applications, confidentiality and integrity are important features to address in order to prevent against attacks. Moreover, network control systems are a fundamental part of the communication components of current cyber-physical systems (e.g., automotive communications). Many networked control systems employ Time-Triggered (TT) architectures that provide mechanisms enabling the exchange of precise and synchronous messages. TT systems have computation and communication constraints, and with the aim to enable secure communications in the network, it is important to evaluate the computational and communication overhead of implementing secure communication mechanisms. This paper presents a comprehensive analysis and evaluation of the effects of adding a Hash-based Message Authentication (HMAC) to TT networked control systems. The contributions of the paper include (1) the analysis and experimental validation of the communication overhead, as well as a scalability analysis that utilizes the experimental result for both wired and wireless platforms and (2) an experimental evaluation of the computational overhead of HMAC based on a kernel-level Linux implementation. An automotive application is used as an example, and the results show that it is feasible to implement a secure communication mechanism without interfering with the existing automotive controller execution times. The methods and results of the paper can be used for evaluating the performance impact of security mechanisms and, thus, for the design of secure wired and wireless TT networked control systems. PMID:27463718

Computation and Communication Evaluation of an Authentication Mechanism for Time-Triggered Networked Control Systems.

PubMed

Martins, Goncalo; Moondra, Arul; Dubey, Abhishek; Bhattacharjee, Anirban; Koutsoukos, Xenofon D

2016-07-25

In modern networked control applications, confidentiality and integrity are important features to address in order to prevent against attacks. Moreover, network control systems are a fundamental part of the communication components of current cyber-physical systems (e.g., automotive communications). Many networked control systems employ Time-Triggered (TT) architectures that provide mechanisms enabling the exchange of precise and synchronous messages. TT systems have computation and communication constraints, and with the aim to enable secure communications in the network, it is important to evaluate the computational and communication overhead of implementing secure communication mechanisms. This paper presents a comprehensive analysis and evaluation of the effects of adding a Hash-based Message Authentication (HMAC) to TT networked control systems. The contributions of the paper include (1) the analysis and experimental validation of the communication overhead, as well as a scalability analysis that utilizes the experimental result for both wired and wireless platforms and (2) an experimental evaluation of the computational overhead of HMAC based on a kernel-level Linux implementation. An automotive application is used as an example, and the results show that it is feasible to implement a secure communication mechanism without interfering with the existing automotive controller execution times. The methods and results of the paper can be used for evaluating the performance impact of security mechanisms and, thus, for the design of secure wired and wireless TT networked control systems.

MSFC Skylab instrumentation and communication system mission evaluation

NASA Technical Reports Server (NTRS)

Adair, B. M.

1974-01-01

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.

NASA Lunar Base Wireless System Propagation Analysis

NASA Technical Reports Server (NTRS)

Hwu, Shian U.; Upanavage, Matthew; Sham, Catherine C.

2007-01-01

There have been many radio wave propagation studies using both experimental and theoretical techniques over the recent years. However, most of studies have been in support of commercial cellular phone wireless applications. The signal frequencies are mostly at the commercial cellular and Personal Communications Service bands. The antenna configurations are mostly one on a high tower and one near the ground to simulate communications between a cellular base station and a mobile unit. There are great interests in wireless communication and sensor systems for NASA lunar missions because of the emerging importance of establishing permanent lunar human exploration bases. Because of the specific lunar terrain geometries and RF frequencies of interest to the NASA missions, much of the published literature for the commercial cellular and PCS bands of 900 and 1800 MHz may not be directly applicable to the lunar base wireless system and environment. There are various communication and sensor configurations required to support all elements of a lunar base. For example, the communications between astronauts, between astronauts and the lunar vehicles, between lunar vehicles and satellites on the lunar orbits. There are also various wireless sensor systems among scientific, experimental sensors and data collection ground stations. This presentation illustrates the propagation analysis of the lunar wireless communication and sensor systems taking into account the three dimensional terrain multipath effects. It is observed that the propagation characteristics are significantly affected by the presence of the lunar terrain. The obtained results indicate the lunar surface material, terrain geometry and antenna location are the important factors affecting the propagation characteristics of the lunar wireless systems. The path loss can be much more severe than the free space propagation and is greatly affected by the antenna height, surface material and operating frequency. The results from this paper are important for the lunar wireless system link margin analysis in order to determine the limits on the reliable communication range, achievable data rate and RF coverage performance at planned lunar base work sites.

Interactive models of communication at the nanoscale using nanoparticles that talk to one another

PubMed Central

Llopis-Lorente, Antoni; Díez, Paula; Sánchez, Alfredo; Marcos, María D.; Sancenón, Félix; Martínez-Ruiz, Paloma; Villalonga, Reynaldo; Martínez-Máñez, Ramón

2017-01-01

‘Communication' between abiotic nanoscale chemical systems is an almost-unexplored field with enormous potential. Here we show the design and preparation of a chemical communication system based on enzyme-powered Janus nanoparticles, which mimics an interactive model of communication. Cargo delivery from one nanoparticle is governed by the biunivocal communication with another nanoparticle, which involves two enzymatic processes and the interchange of chemical messengers. The conceptual idea of establishing communication between nanodevices opens the opportunity to develop complex nanoscale systems capable of sharing information and cooperating. PMID:28556828

System Design for Nano-Network Communications

NASA Astrophysics Data System (ADS)

ShahMohammadian, Hoda

The potential applications of nanotechnology in a wide range of areas necessities nano-networking research. Nano-networking is a new type of networking which has emerged by applying nanotechnology to communication theory. Therefore, this dissertation presents a framework for physical layer communications in a nano-network and addresses some of the pressing unsolved challenges in designing a molecular communication system. The contribution of this dissertation is proposing well-justified models for signal propagation, noise sources, optimum receiver design and synchronization in molecular communication channels. The design of any communication system is primarily based on the signal propagation channel and noise models. Using the Brownian motion and advection molecular statistics, separate signal propagation and noise models are presented for diffusion-based and flow-based molecular communication channels. It is shown that the corrupting noise of molecular channels is uncorrelated and non-stationary with a signal dependent magnitude. The next key component of any communication system is the reception and detection process. This dissertation provides a detailed analysis of the effect of the ligand-receptor binding mechanism on the received signal, and develops the first optimal receiver design for molecular communications. The bit error rate performance of the proposed receiver is evaluated and the impact of medium motion on the receiver performance is investigated. Another important feature of any communication system is synchronization. In this dissertation, the first blind synchronization algorithm is presented for the molecular communication channels. The proposed algorithm uses a non-decision directed maximum likelihood criterion for estimating the channel delay. The Cramer-Rao lower bound is also derived and the performance of the proposed synchronization algorithm is evaluated by investigating its mean square error.

Self-homodyne free-space optical communication system based on orthogonally polarized binary phase shift keying.

PubMed

Cai, Guangyu; Sun, Jianfeng; Li, Guangyuan; Zhang, Guo; Xu, Mengmeng; Zhang, Bo; Yue, Chaolei; Liu, Liren

2016-06-10

A self-homodyne laser communication system based on orthogonally polarized binary phase shift keying is demonstrated. The working principles of this method and the structure of a transceiver are described using theoretical calculations. Moreover, the signal-to-noise ratio, sensitivity, and bit error rate are analyzed for the amplifier-noise-limited case. The reported experiment validates the feasibility of the proposed method and demonstrates its advantageous sensitivity as a self-homodyne communication system.

Developing an evidence base of best practices for integrating computerized systems into the exam room: a systematic review.

PubMed

Patel, Minal R; Vichich, Jennifer; Lang, Ian; Lin, Jessica; Zheng, Kai

2017-04-01

The introduction of health information technology systems, electronic health records in particular, is changing the nature of how clinicians interact with patients. Lack of knowledge remains on how best to integrate such systems in the exam room. The purpose of this systematic review was to (1) distill "best" behavioral and communication practices recommended in the literature for clinicians when interacting with patients in the presence of computerized systems during a clinical encounter, (2) weigh the evidence of each recommendation, and (3) rank evidence-based recommendations for electronic health record communication training initiatives for clinicians. We conducted a literature search of 6 databases, resulting in 52 articles included in the analysis. We extracted information such as study setting, research design, sample, findings, and implications. Recommendations were distilled based on consistent support for behavioral and communication practices across studies. Eight behavioral and communication practices received strong support of evidence in the literature and included specific aspects of using computerized systems to facilitate conversation and transparency in the exam room, such as spatial (re)organization of the exam room, maintaining nonverbal communication, and specific techniques that integrate the computerized system into the visit and engage the patient. Four practices, although patient-centered, have received insufficient evidence to date. We developed an evidence base of best practices for clinicians to maintain patient-centered communications in the presence of computerized systems in the exam room. Further work includes development and empirical evaluation of evidence-based guidelines to better integrate computerized systems into clinical care. © The Author 2016. Published by Oxford University Press on behalf of the American Medical Informatics Association. All rights reserved. For Permissions, please email: journals.permissions@oup.com

Asynchronous error-correcting secure communication scheme based on fractional-order shifting chaotic system

NASA Astrophysics Data System (ADS)

Chao, Luo

2015-11-01

In this paper, a novel digital secure communication scheme is firstly proposed. Different from the usual secure communication schemes based on chaotic synchronization, the proposed scheme employs asynchronous communication which avoids the weakness of synchronous systems and is susceptible to environmental interference. Moreover, as to the transmission errors and data loss in the process of communication, the proposed scheme has the ability to be error-checking and error-correcting in real time. In order to guarantee security, the fractional-order complex chaotic system with the shifting of order is utilized to modulate the transmitted signal, which has high nonlinearity and complexity in both frequency and time domains. The corresponding numerical simulations demonstrate the effectiveness and feasibility of the scheme.

A Review and Analysis of the Picture Exchange Communication System (PECS) for Individuals With Autism Spectrum Disorders Using a Paradigm of Communication Competence

ERIC Educational Resources Information Center

Ostryn, Cheryl; Wolfe, Pamela S.; Rusch, Frank R.

2008-01-01

Research related to the use of the Picture Exchange Communication System (PECS) with individuals having autism spectrum disorders (ASDs) was examined using a communication competence paradigm detailed by J. C. Light (1988, 1989, 2003). Communication components were operationalized based on skills identified in ASD research. A review was conducted…

A Systems Approach to Scaffold Communication Skills Development

PubMed Central

Er, Nelson L.

2008-01-01

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. PMID:18483601

Technology, Data Bases and System Analysis for Space-to-Ground Optical Communications

NASA Technical Reports Server (NTRS)

Lesh, James

1995-01-01

Optical communications is becoming an ever-increasingly important option for designers of space-to- ground communications links, whether it be for government or commercial applications. In this paper the technology being developed by NASA for use in space-to-ground optical communications is presented. Next, a program which is collecting a long term data base of atmospheric visibility statistics for optical propagation through the atmosphere will be described. Finally, a methodology for utilizing the statistics of the atmospheric data base in the analysis of space-to-ground links will be presented. This methodology takes into account the effects of station availability, is useful when comparing optical communications with microwave systems, and provides a rationale establishing the recommended link margin.

Transforming medical imaging applications into collaborative PACS-based telemedical systems

NASA Astrophysics Data System (ADS)

Maani, Rouzbeh; Camorlinga, Sergio; Arnason, Neil

2011-03-01

Telemedical systems are not practical for use in a clinical workflow unless they are able to communicate with the Picture Archiving and Communications System (PACS). On the other hand, there are many medical imaging applications that are not developed as telemedical systems. Some medical imaging applications do not support collaboration and some do not communicate with the PACS and therefore limit their usability in clinical workflows. This paper presents a general architecture based on a three-tier architecture model. The architecture and the components developed within it, transform medical imaging applications into collaborative PACS-based telemedical systems. As a result, current medical imaging applications that are not telemedical, not supporting collaboration, and not communicating with PACS, can be enhanced to support collaboration among a group of physicians, be accessed remotely, and be clinically useful. The main advantage of the proposed architecture is that it does not impose any modification to the current medical imaging applications and does not make any assumptions about the underlying architecture or operating system.

Research of real-time communication software

NASA Astrophysics Data System (ADS)

Li, Maotang; Guo, Jingbo; Liu, Yuzhong; Li, Jiahong

2003-11-01

Real-time communication has been playing an increasingly important role in our work, life and ocean monitor. With the rapid progress of computer and communication technique as well as the miniaturization of communication system, it is needed to develop the adaptable and reliable real-time communication software in the ocean monitor system. This paper involves the real-time communication software research based on the point-to-point satellite intercommunication system. The object-oriented design method is adopted, which can transmit and receive video data and audio data as well as engineering data by satellite channel. In the real-time communication software, some software modules are developed, which can realize the point-to-point satellite intercommunication in the ocean monitor system. There are three advantages for the real-time communication software. One is that the real-time communication software increases the reliability of the point-to-point satellite intercommunication system working. Second is that some optional parameters are intercalated, which greatly increases the flexibility of the system working. Third is that some hardware is substituted by the real-time communication software, which not only decrease the expense of the system and promotes the miniaturization of communication system, but also aggrandizes the agility of the system.

Channel coding for underwater acoustic single-carrier CDMA communication system

NASA Astrophysics Data System (ADS)

Liu, Lanjun; Zhang, Yonglei; Zhang, Pengcheng; Zhou, Lin; Niu, Jiong

2017-01-01

CDMA is an effective multiple access protocol for underwater acoustic networks, and channel coding can effectively reduce the bit error rate (BER) of the underwater acoustic communication system. For the requirements of underwater acoustic mobile networks based on CDMA, an underwater acoustic single-carrier CDMA communication system (UWA/SCCDMA) based on the direct-sequence spread spectrum is proposed, and its channel coding scheme is studied based on convolution, RA, Turbo and LDPC coding respectively. The implementation steps of the Viterbi algorithm of convolutional coding, BP and minimum sum algorithms of RA coding, Log-MAP and SOVA algorithms of Turbo coding, and sum-product algorithm of LDPC coding are given. An UWA/SCCDMA simulation system based on Matlab is designed. Simulation results show that the UWA/SCCDMA based on RA, Turbo and LDPC coding have good performance such that the communication BER is all less than 10-6 in the underwater acoustic channel with low signal to noise ratio (SNR) from -12 dB to -10dB, which is about 2 orders of magnitude lower than that of the convolutional coding. The system based on Turbo coding with Log-MAP algorithm has the best performance.

Picture Exchange Communication System with Individuals with Developmental Disabilities: A Meta-Analysis of Single Subject Studies

ERIC Educational Resources Information Center

Hart, Stephanie L.; Banda, Devender R.

2010-01-01

Picture Exchange Communication System (PECS) is a picture-based communication strategy used to teach communication skills to persons with developmental disabilities including autism. This article systematically reviews 13 published single-subject studies to examine the effectiveness of PECS, the effects of PECS on speech and problem behaviors,…

A comprehensive study of sampling-based optimum signal detection in concentration-encoded molecular communication.

PubMed

Mahfuz, Mohammad U; Makrakis, Dimitrios; Mouftah, Hussein T

2014-09-01

In this paper, a comprehensive analysis of the sampling-based optimum signal detection in ideal (i.e., free) diffusion-based concentration-encoded molecular communication (CEMC) system has been presented. A generalized amplitude-shift keying (ASK)-based CEMC system has been considered in diffusion-based noise and intersymbol interference (ISI) conditions. Information is encoded by modulating the amplitude of the transmission rate of information molecules at the TN. The critical issues involved in the sampling-based receiver thus developed are addressed in detail, and its performance in terms of the number of samples per symbol, communication range, and transmission data rate is evaluated. ISI produced by the residual molecules deteriorates the performance of the CEMC system significantly, which further deteriorates when the communication range and/or the transmission data rate increase(s). In addition, the performance of the optimum receiver depends on the receiver's ability to compute the ISI accurately, thus providing a trade-off between receiver complexity and achievable bit error rate (BER). Exact and approximate detection performances have been derived. Finally, it is found that the sampling-based signal detection scheme thus developed can be applied to both binary and multilevel (M-ary) ASK-based CEMC systems, although M-ary systems suffer more from higher BER.

Development of a demand assignment/TDMA system for international business satellite communications

NASA Astrophysics Data System (ADS)

Nohara, Mitsuo; Takeuchi, Yoshio; Takahata, Fumio; Hirata, Yasuo; Yamazaki, Yoshiharu

An experimental IBS (international business satellite) communications system based on a demand assignment and TDMA (time-division multiple-access) operation has been developed. The system utilizes a limited satellite resource efficiently and provides various kinds of ISDN services totally. A discussion is presented of the IBS network configurations suitable to international communications and describes the developed communications system from the viewpoint of the hardware and software implementation. The performance in terms of the transmission quality and call processing is also demonstrated.

Innovative telecommunications for law enforcement

NASA Technical Reports Server (NTRS)

Sohn, R. L.

1976-01-01

The operation of computer-aided dispatch, mobile digital communications, and automatic vehicle location systems used in law enforcement is discussed, and characteristics of systems used by different agencies are compared. With reference to computer-aided dispatch systems, the data base components, dispatcher work load, extent of usage, and design trends are surveyed. The capabilities, levels of communication, and traffic load of mobile digital communications systems are examined. Different automatic vehicle location systems are distinguished, and two systems are evaluated. Other aspects of the application of innovative technology to operational command, control, and communications systems for law enforcement agencies are described.

Communications and Intelligent Systems Division Overview

NASA Technical Reports Server (NTRS)

Emerson, Dawn

2017-01-01

Provides expertise, and plans, conducts and directs research and engineering development in the competency fields of advanced communications and intelligent systems technologies for applications in current and future aeronautics and space systems.Advances communication systems engineering, development and analysis needed for Glenn Research Center's leadership in communications and intelligent systems technology. Focus areas include advanced high frequency devices, components, and antennas; optical communications, health monitoring and instrumentation; digital signal processing for communications and navigation, and cognitive radios; network architectures, protocols, standards and network-based applications; intelligent controls, dynamics and diagnostics; and smart micro- and nano-sensors and harsh environment electronics. Research and discipline engineering allow for the creation of innovative concepts and designs for aerospace communication systems with reduced size and weight, increased functionality and intelligence. Performs proof-of-concept studies and analyses to assess the impact of the new technologies.

The Capacity Gain of Orbital Angular Momentum Based Multiple-Input-Multiple-Output System

PubMed Central

Zhang, Zhuofan; Zheng, Shilie; Chen, Yiling; Jin, Xiaofeng; Chi, Hao; Zhang, Xianmin

2016-01-01

Wireless communication using electromagnetic wave carrying orbital angular momentum (OAM) has attracted increasing interest in recent years, and its potential to increase channel capacity has been explored widely. In this paper, we compare the technique of using uniform linear array consist of circular traveling-wave OAM antennas for multiplexing with the conventional multiple-in-multiple-out (MIMO) communication method, and numerical results show that the OAM based MIMO system can increase channel capacity while communication distance is long enough. An equivalent model is proposed to illustrate that the OAM multiplexing system is equivalent to a conventional MIMO system with a larger element spacing, which means OAM waves could decrease the spatial correlation of MIMO channel. In addition, the effects of some system parameters, such as OAM state interval and element spacing, on the capacity advantage of OAM based MIMO are also investigated. Our results reveal that OAM waves are complementary with MIMO method. OAM waves multiplexing is suitable for long-distance line-of-sight (LoS) communications or communications in open area where the multi-path effect is weak and can be used in massive MIMO systems as well. PMID:27146453

The design and research of anti-color-noise chaos M-ary communication system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fu, Yongqing, E-mail: fuyongqing@hrbeu.edu.cn; Li, Xingyuan; Li, Yanan

Previously a novel chaos M-ary digital communication method based on spatiotemporal chaos Hamilton oscillator has been proposed. Without chaos synchronization circumstance, it has performance improvement in bandwidth efficiency, transmission efficiency and anti-white-noise performance compared with traditional communication method. In this paper, the channel noise influence on chaotic modulation signals and the construction problem of anti-color-noise chaotic M-ary communication system are studied. The formula of zone partition demodulator’s boundary in additive white Gaussian noise is derived, besides, the problem about how to determine the boundary of zone partition demodulator in additive color noise is deeply studied; Then an approach on constructingmore » anti-color-noise chaos M-ary communication system is proposed, in which a pre-distortion filter is added after the chaos baseband modulator in the transmitter and whitening filter is added before zone partition demodulator in the receiver. Finally, the chaos M-ary communication system based on Hamilton oscillator is constructed and simulated in different channel noise. The result shows that the proposed method in this paper can improve the anti-color-noise performance of the whole communication system compared with the former system, and it has better anti-fading and resisting disturbance performance than Quadrature Phase Shift Keying system.« less

AMPA experimental communications systems

NASA Technical Reports Server (NTRS)

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

1982-01-01

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.

Apollo experience report: Communications system flight evaluation and verification

NASA Technical Reports Server (NTRS)

Travis, D.; Royston, C. L., Jr.

1972-01-01

Flight tests of the synergetic operation of the spacecraft and earth based communications equipment were accomplished during Apollo missions AS-202 through Apollo 12. The primary goals of these tests were to verify that the communications system would adequately support lunar landing missions and to establish the inflight communications system performance characteristics. To attain these goals, a communications system flight verification and evaluation team was established. The concept of the team operations, the evolution of the evaluation processes, synopses of the team activities associated with each mission, and major conclusions and recommendations resulting from the performance evaluation are represented.

Experimental demonstration of OFDM/OQAM transmission with DFT-based channel estimation for visible laser light communications

NASA Astrophysics Data System (ADS)

He, Jing; Shi, Jin; Deng, Rui; Chen, Lin

2017-08-01

Recently, visible light communication (VLC) based on light-emitting diodes (LEDs) is considered as a candidate technology for fifth-generation (5G) communications, VLC is free of electromagnetic interference and it can simplify the integration of VLC into heterogeneous wireless networks. Due to the data rates of VLC system limited by the low pumping efficiency, small output power and narrow modulation bandwidth, visible laser light communication (VLLC) system with laser diode (LD) has paid more attention. In addition, orthogonal frequency division multiplexing/offset quadrature amplitude modulation (OFDM/OQAM) is currently attracting attention in optical communications. Due to the non-requirement of cyclic prefix (CP) and time-frequency domain well-localized pulse shapes, it can achieve high spectral efficiency. Moreover, OFDM/OQAM has lower out-of-band power leakage so that it increases the system robustness against inter-carrier interference (ICI) and frequency offset. In this paper, a Discrete Fourier Transform (DFT)-based channel estimation scheme combined with the interference approximation method (IAM) is proposed and experimentally demonstrated for VLLC OFDM/OQAM system. The performance of VLLC OFDM/OQAM system with and without DFT-based channel estimation is investigated. Moreover, the proposed DFT-based channel estimation scheme and the intra-symbol frequency-domain averaging (ISFA)-based method are also compared for the VLLC OFDM/OQAM system. The experimental results show that, the performance of EVM using the DFT-based channel estimation scheme is improved about 3dB compared with the conventional IAM method. In addition, the DFT-based channel estimation scheme can resist the channel noise effectively than that of the ISFA-based method.

Remote sensing using MIMO systems

DOEpatents

Bikhazi, Nicolas; Young, William F; Nguyen, Hung D

2015-04-28

A technique for sensing a moving object within a physical environment using a MIMO communication link includes generating a channel matrix based upon channel state information of the MIMO communication link. The physical environment operates as a communication medium through which communication signals of the MIMO communication link propagate between a transmitter and a receiver. A spatial information variable is generated for the MIMO communication link based on the channel matrix. The spatial information variable includes spatial information about the moving object within the physical environment. A signature for the moving object is generated based on values of the spatial information variable accumulated over time. The moving object is identified based upon the signature.

Experimental research and comparison of LDPC and RS channel coding in ultraviolet communication systems.

PubMed

Wu, Menglong; Han, Dahai; Zhang, Xiang; Zhang, Feng; Zhang, Min; Yue, Guangxin

2014-03-10

We have implemented a modified Low-Density Parity-Check (LDPC) codec algorithm in ultraviolet (UV) communication system. Simulations are conducted with measured parameters to evaluate the LDPC-based UV system performance. Moreover, LDPC (960, 480) and RS (18, 10) are implemented and experimented via a non-line-of-sight (NLOS) UV test bed. The experimental results are in agreement with the simulation and suggest that based on the given power and 10(-3)bit error rate (BER), in comparison with an uncoded system, average communication distance increases 32% with RS code, while 78% with LDPC code.

Electric vehicle equipment for grid-integrated vehicles

DOEpatents

Kempton, Willett

2013-08-13

Methods, systems, and apparatus for interfacing an electric vehicle with an electric power grid are disclosed. An exemplary apparatus may include a station communication port for interfacing with electric vehicle station equipment (EVSE), a vehicle communication port for interfacing with a vehicle management system (VMS), and a processor coupled to the station communication port and the vehicle communication port to establish communication with the EVSE via the station communication port, receive EVSE attributes from the EVSE, and issue commands to the VMS to manage power flow between the electric vehicle and the EVSE based on the EVSE attributes. An electric vehicle may interface with the grid by establishing communication with the EVSE, receiving the EVSE attributes, and managing power flow between the EVE and the grid based on the EVSE attributes.

Communication system modeling

NASA Technical Reports Server (NTRS)

Holland, L. D.; Walsh, J. R., Jr.; Wetherington, R. D.

1971-01-01

This report presents the results of work on communications systems modeling and covers three different areas of modeling. The first of these deals with the modeling of signals in communication systems in the frequency domain and the calculation of spectra for various modulations. These techniques are applied in determining the frequency spectra produced by a unified carrier system, the down-link portion of the Command and Communications System (CCS). The second modeling area covers the modeling of portions of a communication system on a block basis. A detailed analysis and modeling effort based on control theory is presented along with its application to modeling of the automatic frequency control system of an FM transmitter. A third topic discussed is a method for approximate modeling of stiff systems using state variable techniques.

Train integrity detection risk analysis based on PRISM

NASA Astrophysics Data System (ADS)

Wen, Yuan

2018-04-01

GNSS based Train Integrity Monitoring System (TIMS) is an effective and low-cost detection scheme for train integrity detection. However, as an external auxiliary system of CTCS, GNSS may be influenced by external environments, such as uncertainty of wireless communication channels, which may lead to the failure of communication and positioning. In order to guarantee the reliability and safety of train operation, a risk analysis method of train integrity detection based on PRISM is proposed in this article. First, we analyze the risk factors (in GNSS communication process and the on-board communication process) and model them. Then, we evaluate the performance of the model in PRISM based on the field data. Finally, we discuss how these risk factors influence the train integrity detection process.

NASA's K/Ka-Band Broadband Aeronautical Terminal for Duplex Satellite Video Communications

NASA Technical Reports Server (NTRS)

Densmore, A.; Agan, M.

1994-01-01

JPL has recently begun the development of a Broadband Aeronautical Terminal (BAT) for duplex video satellite communications on commercial or business class aircraft. The BAT is designed for use with NASA's K/Ka-band Advanced Communications Technology Satellite (ACTS). The BAT system will provide the systems and technology groundwork for an eventual commercial K/Ka-band aeronautical satellite communication system. With industry/government partnerships, three main goals will be addressed by the BAT task: 1) develop, characterize and demonstrate the performance of an ACTS based high data rate aeronautical communications system; 2) assess the performance of current video compression algorithms in an aeronautical satellite communication link; and 3) characterize the propagation effects of the K/Ka-band channel for aeronautical communications.

Video Feedforward for Rapid Learning of a Picture-Based Communication System

ERIC Educational Resources Information Center

Smith, Jemma; Hand, Linda; Dowrick, Peter W.

2014-01-01

This study examined the efficacy of video self modeling (VSM) using feedforward, to teach various goals of a picture exchange communication system (PECS). The participants were two boys with autism and one man with Down syndrome. All three participants were non-verbal with no current functional system of communication; the two children had long…

Communications interface for wireless communications headset

NASA Technical Reports Server (NTRS)

Culotta, Jr., Anthony Joseph (Inventor); Seibert, Marc A. (Inventor)

2004-01-01

A universal interface adapter circuit interfaces, for example, a wireless communications headset with any type of communications system, including those that require push-to-talk (PTT) signaling. The interface adapter is comprised of several main components, including an RF signaling receiver, a microcontroller and associated circuitry for decoding and processing the received signals, and programmable impedance matching and line interfacing circuitry for interfacing a wireless communications headset system base to a communications system. A signaling transmitter, which is preferably portable (e.g., handheld), is employed by the wireless headset user to send signals to the signaling receiver. In an embodiment of the invention directed specifically to push-to-talk (PTT) signaling, the wireless headset user presses a button on the signaling transmitter when they wish to speak. This sends a signal to the microcontroller which decodes the signal and recognizes the signal as being a PTT request. In response, the microcontroller generates a control signal that closes a switch to complete a voice connection between the headset system base and the communications system so that the user can communicate with the communications system. With this arrangement, the wireless headset can be interfaced to any communications system that requires PTT signaling, without modification of the headset device. In addition, the interface adapter can also be configured to respond to or deliver any other types of signals, such as dual-tone-multiple-frequency (DTMF) tones, and on/off hook signals. The present invention is also scalable, and permits multiple wireless users to operate independently in the same environment through use of a plurality of the interface adapters.

Energy efficiency in wireless communication systems

DOEpatents

Caffrey, Michael Paul; Palmer, Joseph McRae

2012-12-11

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.

NASA Hitchhiker Program Customer Payload Requirements (CPR)

NASA Technical Reports Server (NTRS)

Horan, Stephen

1998-01-01

The mission objective is to demonstrate each of the three types of technology intended for future small-satellite communications system design. Each experiment in the overall package is designed to exercise a different technology objective that may be found in the overall satellite communications and telemetry system design. The data communications through TORSS portion is designed to demonstrate that low-power communications systems with non-gimbaled antenna systems can transport significant quantities of data through TDRSS to the ground based on only transmitting through a TDRS when the experiment is near the TDRS subsatellite point. The remaining time. the payload communications system is not active. The demand access experiment is to demonstrate that the request for a demand access service can be transmitted through TDRS and received and decoded at the ground station. In this mode, the TDRS does not track the experiment but signal processing components at the White Sands Complex are used to detect and track the transmitted request. The laser communications experiment is designed to demonstrate passive transmission of telemetry data from the experiment. This mode uses a ground-based laser source to illuminate the experiment and modulate the beam with the data. Ground-based reception recovers the data from the reflected beam back to the ground station.

All-optical virtual private network and ONUs communication in optical OFDM-based PON system.

PubMed

Zhang, Chongfu; Huang, Jian; Chen, Chen; Qiu, Kun

2011-11-21

We propose and demonstrate a novel scheme, which enables all-optical virtual private network (VPN) and all-optical optical network units (ONUs) inter-communications in optical orthogonal frequency-division multiplexing-based passive optical network (OFDM-PON) system using the subcarrier bands allocation for the first time (to our knowledge). We consider the intra-VPN and inter-VPN communications which correspond to two different cases: VPN communication among ONUs in one group and in different groups. The proposed scheme can provide the enhanced security and a more flexible configuration for VPN users compared to the VPN in WDM-PON or TDM-PON systems. The all-optical VPN and inter-ONU communications at 10-Gbit/s with 16 quadrature amplitude modulation (16 QAM) for the proposed optical OFDM-PON system are demonstrated. These results verify that the proposed scheme is feasible. © 2011 Optical Society of America

Introduction of a guide to enhance risk communication among low-income and minority populations: a grassroots community engagement approach.

PubMed

Rowel, Randy; Sheikhattari, Payam; Barber, Tanyka M; Evans-Holland, Myrtle

2012-01-01

Low-income populations, especially those belonging to minority groups, are among the most vulnerable groups before, during, and after a natural disaster. One of the factors that can be attributed to their vulnerability is the ineffectiveness of traditional risk communication systems in reaching this population. Many low-income populations are distrustful of government agencies and those who typically communicate risk messages. Consequently, traditional systems are not as effective in reaching these communities. Furthermore, traditional systems have been based on the social media that the general population uses and not based on social networks of disadvantaged populations which are more important than formal channels in these communities for dissemination of information. To bridge the gap, an approach is needed that relies on trusted agencies and leaders to educate and warn low-income communities about possible public health threats. A grassroots approach can enhance the capacity of the risk communication systems to more effectively reach vulnerable populations by engaging grassroots organizations in risk communication activities. The Guide to Enhance Grassroots Risk Communication Among Low-Income Populations provides strategies and guidance that can assist agencies in upgrading their systems for risk communication by building partnerships with local community stakeholders.

Auto-Generated Semantic Processing Services

NASA Technical Reports Server (NTRS)

Davis, Rodney; Hupf, Greg

2009-01-01

Auto-Generated Semantic Processing (AGSP) Services is a suite of software tools for automated generation of other computer programs, denoted cross-platform semantic adapters, that support interoperability of computer-based communication systems that utilize a variety of both new and legacy communication software running in a variety of operating- system/computer-hardware combinations. AGSP has numerous potential uses in military, space-exploration, and other government applications as well as in commercial telecommunications. The cross-platform semantic adapters take advantage of common features of computer- based communication systems to enforce semantics, messaging protocols, and standards of processing of streams of binary data to ensure integrity of data and consistency of meaning among interoperating systems. The auto-generation aspect of AGSP Services reduces development time and effort by emphasizing specification and minimizing implementation: In effect, the design, building, and debugging of software for effecting conversions among complex communication protocols, custom device mappings, and unique data-manipulation algorithms is replaced with metadata specifications that map to an abstract platform-independent communications model. AGSP Services is modular and has been shown to be easily integrable into new and legacy NASA flight and ground communication systems.

Effectiveness of the Picture Exchange Communication System as a Functional Communication Intervention for Individuals with Autism Spectrum Disorders: A Practice-Based Research Synthesis

ERIC Educational Resources Information Center

Tien, Kai-Chien

2008-01-01

This research synthesis verifies the effectiveness of the Picture Exchange Communication System (PECS) for improving the functional communication skills of individuals with autism spectrum disorders (ASD). The research synthesis was focused on the degree to which variations in PECS training are associated with variations in functional…

A native IP satellite communications system

NASA Astrophysics Data System (ADS)

Koudelka, O.; Schmidt, M.; Ebert, J.; Schlemmer, H.; Kastner-Puschl, S.; Riedler, W.

2004-08-01

≪ In the framework of ESA's ARTES-5 program the Institute of Applied Systems Technology (Joanneum Research) in cooperation with the Department of Communications and Wave Propagation has developed a novel meshed satellite communications system which is optimised for Internet traffic and applications (L*IP—Local Network Interconnection via Satellite Systems Using the IP Protocol Suite). Both symmetrical and asymmetrical connections are supported. Bandwidth on demand and guaranteed quality of service are key features of the system. A novel multi-frequency TDMA access scheme utilises efficient methods of IP encapsulation. In contrast to other solutions it avoids legacy transport network techniques. While the DVB-RCS standard is based on ATM or MPEG transport cells, the solution of the L*IP system uses variable-length cells which reduces the overhead significantly. A flexible and programmable platform based on Linux machines was chosen to allow the easy implementation and adaptation to different standards. This offers the possibility to apply the system not only to satellite communications, but provides seamless integration with terrestrial fixed broadcast wireless access systems. The platform is also an ideal test-bed for a variety of interactive broadband communications systems. The paper describes the system architecture and the key features of the system.

Application of the Iridium Satellite System to Aeronautical Communications

NASA Technical Reports Server (NTRS)

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

2008-01-01

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.

Personal digital assistant-based, internet-enabled remote communication system for a wearable pneumatic biventricular assist device.

PubMed

Nam, Kyoung Won; Lee, Jung Joo; Hwang, Chang Mo; Choi, Seong Wook; Son, Ho Sung; Sun, Kyung

2007-11-01

Currently, personal mobile communication devices have become quite common, and the applications of such devices have expanded quickly. Remote communication systems might be employed for the telemonitoring of patients or the operating status of their medical devices. In this article, we describe the development of a mobile-based artificial heart telemanagement system for use in a wearable extracorporeal pneumatic biventricular assist device, which is capable of telemonitoring and telecontrolling the operating status of the ventricular assist device from any site. The system developed herein utilized small mobile phones for the client device and adopted a standard transmission control protocol/Internet protocol communication protocol for the purposes of telecommunication. The results of in vitro and animal experiments showed that the telemanagement system developed herein operated in accordance with the desired parameters.

Communications satellite systems operations with the space station, volume 2

NASA Technical Reports Server (NTRS)

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

1987-01-01

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.

1Mbps NLOS solar-blind ultraviolet communication system based on UV-LED array

NASA Astrophysics Data System (ADS)

Sun, Zhaotian; Zhang, Lijun; Li, Ping'an; Qin, Yu; Bai, Tingzhu

2018-01-01

We proposed and demonstrated a high data rate ultraviolet communication system based on a 266nm UV LED array with 50mW luminous power. The emitting source is driven by a three outputs constant-current control circuit, whose driving speed is up to 2Mbps. At the receiving side, in order to achieve the amplification for high-speed signal, a two-stage differential preamplifier is designed to make I-V conversion. The voltage-current gain is up to 140dB and bandwidth is 1.9MHz. An experiment is conducted to test the performance of the UV communication system. The effects of elevation angles and transmission distance are analyzed. It is shown that the ultraviolet communication system has high data rate of up to 921.6kbps and bit error rate of less than 10-7 in 150m, which can beat the best record created by UV-LED communication system in terms of the transmission rate.

Video feedforward for rapid learning of a picture-based communication system.

PubMed

Smith, Jemma; Hand, Linda; Dowrick, Peter W

2014-04-01

This study examined the efficacy of video self modeling (VSM) using feedforward, to teach various goals of a picture exchange communication system (PECS). The participants were two boys with autism and one man with Down syndrome. All three participants were non-verbal with no current functional system of communication; the two children had long histories of PECS failure. A series of replications, with different length baselines, was used to examine whether video self modeling could replace the PECS method of teaching to achieve the same goals. All three participants showed rapid learning of their target behavior when introduced to their self modeling videos, and effects generalized without the need for further intervention. We conclude that VSM, using feedforward, can provide a fast, simple way of teaching the use of a picture-based communication system without the need for prompts or intensive operant conditioning. VSM may provide an accessible, easy-to-use alternative to common methods of teaching augmentative and alternative communication systems.

Communication protocol in chassis detecting wireless transmission system based on WiFi

USDA-ARS?s Scientific Manuscript database

In chassis detecting wireless transmission system, the wireless network communication protocol plays a key role in the information exchange and synchronization between the host and chassis PDA. This paper presents a wireless network transmission protocol based on TCP/IP which makes the rules of info...

A web-based communication system for integrated care in cerebral palsy: design features, technical feasibility and usability.

PubMed

Gulmans, Jitske; Vollenbroek-Hutten, Miriam M R; Visser, Jacqueline J W; Nijeweme-d'Hollosy, Wendy Oude; van Gemert-Pijnen, J E W C Lisette; van Harten, Wim H

2010-01-01

We developed a secure, web-based system for parent-professional and inter-professional communication. The aim was to improve communication in the care of children with cerebral palsy. We conducted a six-month trial of the system in three Dutch health-care regions. The participants were the parents of 30 cerebral palsy patients and 120 professional staff involved in their care. Information about system usage was extracted from the system's database. The experience of the parents and professionals was evaluated by a questionnaire after six months. The system proved to be technically robust and reliable. A total of 21 parents (70%) and 66 professionals (55%) used the system. The parents submitted 111 questions and 59 responses, with a mean of 5 questions (range 1-17) and 3 responses (range 1-9) per parent. The professionals submitted 79 questions and 237 responses, with a mean of 2 questions (range 1-8) and 4 responses (range 1-23) per professional. Most parents (95%) and some professionals (30%) reported value in using the system, which ranged from efficiency and accessibility to flexibility and transparency. The web-based communication system was technically feasible and produced improved parent-professional and inter-professional communication. It may be especially valuable if frequent interventions or consultations about a child's care are required, involving complex care networks of different professionals and organisations.

Policy-based secure communication with automatic key management for industrial control and automation systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chernoguzov, Alexander; Markham, Thomas R.; Haridas, Harshal S.

A method includes generating at least one access vector associated with a specified device in an industrial process control and automation system. The specified device has one of multiple device roles. The at least one access vector is generated based on one or more communication policies defining communications between one or more pairs of devices roles in the industrial process control and automation system, where each pair of device roles includes the device role of the specified device. The method also includes providing the at least one access vector to at least one of the specified device and one ormore » more other devices in the industrial process control and automation system in order to control communications to or from the specified device.« less

High data rate modem simulation for the space station multiple-access communications system

NASA Technical Reports Server (NTRS)

Horan, Stephen

1987-01-01

The communications system for the space station will require a space based multiple access component to provide communications between the space based program elements and the station. A study was undertaken to investigate two of the concerns of this multiple access system, namely, the issues related to the frequency spectrum utilization and the possibilities for higher order (than QPSK) modulation schemes for use in possible modulators and demodulators (modems). As a result of the investigation, many key questions about the frequency spectrum utilization were raised. At this point, frequency spectrum utilization is seen as an area requiring further work. Simulations were conducted using a computer aided communications system design package to provide a straw man modem structure to be used for both QPSK and 8-PSK channels.

GLOBECOM '87 - Global Telecommunications Conference, Tokyo, Japan, Nov. 15-18, 1987, Conference Record. Volumes 1, 2, & 3

NASA Astrophysics Data System (ADS)

The present conference on global telecommunications discusses topics in the fields of Integrated Services Digital Network (ISDN) technology field trial planning and results to date, motion video coding, ISDN networking, future network communications security, flexible and intelligent voice/data networks, Asian and Pacific lightwave and radio systems, subscriber radio systems, the performance of distributed systems, signal processing theory, satellite communications modulation and coding, and terminals for the handicapped. Also discussed are knowledge-based technologies for communications systems, future satellite transmissions, high quality image services, novel digital signal processors, broadband network access interface, traffic engineering for ISDN design and planning, telecommunications software, coherent optical communications, multimedia terminal systems, advanced speed coding, portable and mobile radio communications, multi-Gbit/second lightwave transmission systems, enhanced capability digital terminals, communications network reliability, advanced antimultipath fading techniques, undersea lightwave transmission, image coding, modulation and synchronization, adaptive signal processing, integrated optical devices, VLSI technologies for ISDN, field performance of packet switching, CSMA protocols, optical transport system architectures for broadband ISDN, mobile satellite communications, indoor wireless communication, echo cancellation in communications, and distributed network algorithms.

BER Analysis of Coherent Free-Space Optical Communication Systems with a Focal-Plane-Based Wavefront Sensor

NASA Astrophysics Data System (ADS)

Cao, Jingtai; Zhao, Xiaohui; Liu, Wei; Gu, Haijun

2018-03-01

A wavefront sensor is one of most important units for an adaptive optics system. Based on our previous works, in this paper, we discuss the bit-error-rate (BER) performance of coherent free space optical communication systems with a focal-plane-based wavefront sensor. Firstly, the theory of a focal-plane-based wavefront sensor is given. Then the relationship between the BER and the mixing efficiency with a homodyne receiver is discussed on the basis of binary-phase-shift-keying (BPSK) modulation. Finally, the numerical simulation results are shown that the BER will be decreased obviously after aberrations correction with the focal-plane-based wavefront sensor. In addition, the BER will decrease along with increasing number of photons received within a single bit. These analysis results will provide a reference for the design of the coherent Free space optical communication (FSOC) system.

Experimental Evaluation of the Training Structure of the Picture Exchange Communication System (PECS)

ERIC Educational Resources Information Center

Cummings, Anne R.; Carr, James E.; LeBlanc, Linda A.

2012-01-01

The Picture Exchange Communication System (PECS) is a picture-based alternative communication method that is widely accepted and utilized with individuals with disabilities. Although prior studies have examined the clinical efficacy of PECS, none have experimentally evaluated its manualized training structure. We experimentally evaluated the…

Orthogonal frequency-division multiplexing access (OFDMA) based wireless visible light communication (VLC) system

NASA Astrophysics Data System (ADS)

Sung, Jiun-Yu; Yeh, Chien-Hung; Chow, Chi-Wai; Lin, Wan-Feng; Liu, Yang

2015-11-01

An orthogonal frequency-division multiplexing access (OFDMA) based visible light communication (VLC) system is proposed in this paper. The architecture of the proposed system is divided into several VLC cells, which is defined in this paper. The deployment and upgrade of the system involve only simple combination of the VLC cells. Hence it is economically advantageous. To guarantee smooth communication, nearly equal data rate is provided at every location within the system with no concern on the system scale. The user location monitor strategy is also discussed to solve the region division issues. The characteristics of the proposed system are analyzed in detail in this paper. A one-dimensional experiment was demonstrated with 13.6 Mb/s data rate.

[Communication subsystem design of tele-screening system for diabetic retinopathy].

PubMed

Chen, Jian; Pan, Lin; Zheng, Shaohua; Yu, Lun

2013-12-01

A design scheme of a tele-screening system for diabetic retinopathy (DR) has been proposed, especially the communication subsystem. The scheme uses serial communication module consisting of ARM 7 microcontroller and relays to connect remote computer and fundus camera, and also uses C++ programming language based on MFC to design the communication software consisting of therapy and diagnostic information module, video/audio surveillance module and fundus camera control module. The scheme possesses universal property in some remote medical treatment systems which are similar to the system.

Land mobile satellite communication system. Volume 2: Traffic analysis and market demand for the land mobile communications system in the European scenario

NASA Astrophysics Data System (ADS)

Carnebianca, C.; Pavesi, B.; Tuozzi, A.; Capone, R.

1986-06-01

The socioeconomic desirability in terms of market demand, technical economic feasibility, and price-performance for a Land Mobile Communication system ground based and/or satellite aided, able to satisfy the request of the traffic demand, foreseable in the 1995-2005 time frame, for the Western European countries was assessed. The criterion of economic value of the mobile system is considered as the driving element. The presence of gaps in the terrestrial system and reasonable traffic extrapolations suggest a very attractive role for a land mobile satellite communications mission.

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

NASA Technical Reports Server (NTRS)

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

2013-01-01

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.

Tone based command system for reception of very weak signals

NASA Technical Reports Server (NTRS)

Bokulic, Robert Steven (Inventor); Jensen, James Robert (Inventor)

2006-01-01

This disclosure presents a communication receiver system for spacecraft that includes an open loop receiver adapted to receive a communication signal. An ultrastable oscillator (USO) and a tone detector are connected to the open loop receiver. The open loop receiver translates the communication signal to an intermediate frequency signal using a highly stable reference frequency from the USO. The tone detector extracts commands from the communication signal by evaluating the difference between tones of the communication signal.

Towards ontology personalization to enrich social conversations on AAC systems

NASA Astrophysics Data System (ADS)

Mancilla V., Daniela; Sastoque H., Sebastian; Iregui G., Marcela

2015-01-01

Communication is one of the essential needs of human beings. Augmentative and Alternative Communication Systems (AAC) seek to help in the generation of oral and written language to people with physical disorders that limit their natural communication. These systems present significant challenges such as: the composition of consistent messages according to syntactic and semantic rules, the improvement of message production times, the application to social contexts and, consequently, the incorporation of user-specific information. This work presents an original ontology personalization approach for an AAC instant messaging system incorporating personalized information to improve the efficacy and efficiency of the message production. This proposal is based on a projection of a general ontology into a more specific one, avoiding storage redundancy and data coupling, representing a big opportunity to enrich communication capabilities of current AAC systems. The evaluation was performed for a study case based on an AAC system for assistance in composing messages. The results show that adding user-specific information allows generation of enriched phrases, so improving the accuracy of the message, facilitating the communication process.

4.5-Gb/s RGB-LED based WDM visible light communication system employing CAP modulation and RLS based adaptive equalization.

PubMed

Wang, Yiguang; Huang, Xingxing; Tao, Li; Shi, Jianyang; Chi, Nan

2015-05-18

Inter-symbol interference (ISI) is one of the key problems that seriously limit transmission data rate in high-speed VLC systems. To eliminate ISI and further improve the system performance, series of equalization schemes have been widely investigated. As an adaptive algorithm commonly used in wireless communication, RLS is also suitable for visible light communication due to its quick convergence and better performance. In this paper, for the first time we experimentally demonstrate a high-speed RGB-LED based WDM VLC system employing carrier-less amplitude and phase (CAP) modulation and recursive least square (RLS) based adaptive equalization. An aggregate data rate of 4.5Gb/s is successfully achieved over 1.5-m indoor free space transmission with the bit error rate (BER) below the 7% forward error correction (FEC) limit of 3.8x10(-3). To the best of our knowledge, this is the highest data rate ever achieved in RGB-LED based VLC systems.

The Picture Exchange Communication System.

PubMed

Bondy, A; Frost, L

2001-10-01

The Picture Exchange Communication System (PECS) is an alternative/augmentative communication system that was developed to teach functional communication to children with limited speech. The approach is unique in that it teaches children to initiate communicative interactions within a social framework. This article describes the advantages to implementing PECS over traditional approaches. The PECS training protocol is described wherein children are taught to exchange a single picture for a desired item and eventually to construct picture-based sentences and use a variety of attributes in their requests. The relationship of PECS's implementation to the development of speech in previously nonvocal students is reviewed.

Communication in a Web-Based Conferencing System: The Quality of Computer-Mediated Interactions.

ERIC Educational Resources Information Center

Angeli, Charoula; Valanides, Nicos; Bonk, Curtis J.

2003-01-01

Describes a study of undergraduates that investigated the extent to which an electronic conferencing system, COW (Conferencing on the Web) facilitated preservice teachers' communication outside their classroom when discussing teaching cases from their field experiences, and the potential of COW and case-based instruction to foster quality…

Microprocessor-Based Systems Control for the Rigidized Inflatable Get-Away-Special Experiment

DTIC Science & Technology

2004-03-01

communications and faster data throughput increase, satellites are becoming larger. Larger satellite antennas help to provide the needed gain to...increase communications in space. Compounding the performance and size trade-offs are the payload weight and size limit imposed by the launch vehicles...increased communications capacity, and reduce launch costs. This thesis develops and implements the computer control system and power system to

Social Information Processing Analysis (SIPA): Coding Ongoing Human Communication.

ERIC Educational Resources Information Center

Fisher, B. Aubrey; And Others

1979-01-01

The purpose of this paper is to present a new analytical system to be used in communication research. Unlike many existing systems devised ad hoc, this research tool, a system for interaction analysis, is embedded in a conceptual rationale based on modern systems theory. (Author)

A communication theoretical analysis of FRET-based mobile ad hoc molecular nanonetworks.

PubMed

Kuscu, Murat; Akan, Ozgur B

2014-09-01

Nanonetworks refer to a group of nanosized machines with very basic operational capabilities communicating to each other in order to accomplish more complex tasks such as in-body drug delivery, or chemical defense. Realizing reliable and high-rate communication between these nanomachines is a fundamental problem for the practicality of these nanonetworks. Recently, we have proposed a molecular communication method based on Förster Resonance Energy Transfer (FRET) which is a nonradiative excited state energy transfer phenomenon observed among fluorescent molecules, i.e., fluorophores. We have modeled the FRET-based communication channel considering the fluorophores as single-molecular immobile nanomachines, and shown its reliability at high rates, and practicality at the current stage of nanotechnology. In this study, for the first time in the literature, we investigate the network of mobile nanomachines communicating through FRET. We introduce two novel mobile molecular nanonetworks: FRET-based mobile molecular sensor/actor nanonetwork (FRET-MSAN) which is a distributed system of mobile fluorophores acting as sensor or actor node; and FRET-based mobile ad hoc molecular nanonetwork (FRET-MAMNET) which consists of fluorophore-based nanotransmitter, nanoreceivers and nanorelays. We model the single message propagation based on birth-death processes with continuous time Markov chains. We evaluate the performance of FRET-MSAN and FRET-MAMNET in terms of successful transmission probability and mean extinction time of the messages, system throughput, channel capacity and achievable communication rates.

MEMS-Based Communications Systems for Space-Based Applications

NASA Technical Reports Server (NTRS)

DeLosSantos, Hector J.; Brunner, Robert A.; Lam, Juan F.; Hackett, Le Roy H.; Lohr, Ross F., Jr.; Larson, Lawrence E.; Loo, Robert Y.; Matloubian, Mehran; Tangonan, Gregory L.

1995-01-01

As user demand for higher capacity and flexibility in communications satellites increases, new ways to cope with the inherent limitations posed by the prohibitive mass and power consumption, needed to satisfy those requirements, are under investigation. Recent studies suggest that while new satellite architectures are necessary to enable multi-user, multi-data rate, multi-location satellite links, these new architectures will inevitably increase power consumption, and in turn, spacecraft mass, to such an extent that their successful implementation will demand novel lightweight/low power hardware approaches. In this paper, following a brief introduction to the fundamentals of communications satellites, we address the impact of micro-electro-mechanical systems (MEMS) technology, in particular micro-electro-mechanical (MEM) switches to mitigate the above mentioned problems and show that low-loss/wide bandwidth MEM switches will go a long way towards enabling higher capacity and flexibility space-based communications systems.

Role-based access control permissions

DOEpatents

Staggs, Kevin P.; Markham, Thomas R.; Hull Roskos, Julie J.; Chernoguzov, Alexander

2017-04-25

Devices, systems, and methods for role-based access control permissions are disclosed. One method includes a policy decision point that receives up-to-date security context information from one or more outside sources to determine whether to grant access for a data client to a portion of the system and creates an access vector including the determination; receiving, via a policy agent, a request by the data client for access to the portion of the computing system by the data client, wherein the policy agent checks to ensure there is a session established with communications and user/application enforcement points; receiving, via communications policy enforcement point, the request from the policy agent, wherein the communications policy enforcement point determines whether the data client is an authorized node, based upon the access vector received from the policy decision point; and receiving, via the user/application policy enforcement point, the request from the communications policy enforcement point.

Free-space laser communication technologies; Proceedings of the Meeting, Los Angeles, CA, Jan. 11, 12, 1988

NASA Astrophysics Data System (ADS)

Koepf, Gerhard A.; Begley, David L.

1988-01-01

The present conference discusses topics in free-space laser communications, laser link characteristics, satellite laser communication systems, optoelectronic components for laser communications, and space laser subsystem technologies. Attention is given to Space Station-based deep-space communication experiments, the application of intersatellite links to operational satellite systems, high-power 0.87 micron channel substrate planar lasers for spaceborne communications, a ground experiment using a CO2 laser transceiver for free-space communications, studies of laser ranging to the TOPEX satellite, diffraction-limited tracking for space communications, and the compact implementation of a real-time, acoustooptic SAR processor.

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

Design of temperature monitoring system based on CAN bus

NASA Astrophysics Data System (ADS)

Zhang, Li

2017-10-01

The remote temperature monitoring system based on the Controller Area Network (CAN) bus is designed to collect the multi-node remote temperature. By using the STM32F103 as main controller and multiple DS18B20s as temperature sensors, the system achieves a master-slave node data acquisition and transmission based on the CAN bus protocol. And making use of the serial port communication technology to communicate with the host computer, the system achieves the function of remote temperature storage, historical data show and the temperature waveform display.

Wireless Headset Communication System

NASA Technical Reports Server (NTRS)

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

1995-01-01

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.

Research of the key technology in satellite communication networks

NASA Astrophysics Data System (ADS)

Zeng, Yuan

2018-02-01

According to the prediction, in the next 10 years the wireless data traffic will be increased by 500-1000 times. Not only the wireless data traffic will be increased exponentially, and the demand for diversified traffic will be increased. Higher requirements for future mobile wireless communication system had brought huge market space for satellite communication system. At the same time, the space information networks had been greatly developed with the depth of human exploration of space activities, the development of space application, the expansion of military and civilian application. The core of spatial information networks is the satellite communication. The dissertation presented the communication system architecture, the communication protocol, the routing strategy, switch scheduling algorithm and the handoff strategy based on the satellite communication system. We built the simulation platform of the LEO satellites networks and simulated the key technology using OPNET.

Implementing an Internet-based communication network for use during skilled nursing facility to emergency department care transitions: challenges and opportunities for improvement.

PubMed

Hustey, Fredric M; Palmer, Robert M

2012-03-01

To explore the feasibility of implementing an Internet-based communication network for communication of health care information during skilled nursing facility (SNF)-to-ED care transitions, and to identify potential barriers to system implementation. Qualitative. The largest SNF affiliated with the ED of an urban tertiary care center. Consecutive sample of all patients transferred from SNF to ED over 8 months between June 2007 and January 2008; ED and SNF care providers. The development and implementation of an Internet-based communication network for use during SNF-to-ED care transitions. This network was developed by adapting a preexisting Internet-based system that is widely used to facilitate placement of hospitalized patients into SNFs. Internet-based SNF and ED surveys were used to help identify barriers to implementation. There were 276/276 care transitions reviewed. The Internet-based communication network was used in 76 (28%) care transitions, with usage peaking at 40% near the end of the study. Barriers to success that were identified included lack of an electronic medical record (EMR) at the SNF; pervasive negative attitudes between ED and SNF personnel; time necessary for network use during care transitions; frustration by emergency physicians at low system usage rates by SNF personnel; and additional login requirements by ED personnel. Although implementing an Internet-based network for nursing home to ED communication may be feasible, significant barriers were identified in this study that are likely generalizable to other health care settings. Understanding such barriers is an essential first step toward building successful electronic communication networks in the future. Copyright © 2012 American Medical Directors Association, Inc. Published by Elsevier Inc. All rights reserved.

Simultaneous classical communication and quantum key distribution using continuous variables*

NASA Astrophysics Data System (ADS)

Qi, Bing

2016-10-01

Presently, classical optical communication systems employing strong laser pulses and quantum key distribution (QKD) systems working at single-photon levels are very different communication modalities. Dedicated devices are commonly required to implement QKD. In this paper, we propose a scheme which allows classical communication and QKD to be implemented simultaneously using the same communication infrastructure. More specially, we propose a coherent communication scheme where both the bits for classical communication and the Gaussian distributed random numbers for QKD are encoded on the same weak coherent pulse and decoded by the same coherent receiver. Simulation results based on practical system parameters show that both deterministic classical communication with a bit error rate of 10-9 and secure key distribution could be achieved over tens of kilometers of single-mode fibers. It is conceivable that in the future coherent optical communication network, QKD will be operated in the background of classical communication at a minimal cost.

A Communication-Based Intervention for Nonverbal Children with Autism: What Changes? Who Benefits?

ERIC Educational Resources Information Center

Gordon, Kate; Pasco, Greg; McElduff, Fiona; Wade, Angie; Howlin, Pat; Charman, Tony

2011-01-01

Objective: This article examines the form and function of spontaneous communication and outcome predictors in nonverbal children with autism following classroom-based intervention (Picture Exchange Communication System [PECS] training). Method: 84 children from 15 schools participated in a randomized controlled trial (RCT) of PECS (P. Howlin, R.…

Preschoolers with Autism Spectrum Disorders: Evaluating the Impact of a Home-Based Intervention to Promote Their Communication

ERIC Educational Resources Information Center

McConkey, Roy; Truesdale-Kennedy, Maria; Crawford, Heather; McGreevy, Elaine; Reavey, Michaela; Cassidy, Arlene

2010-01-01

The complexities that practitioners face in evaluating interventions are illustrated in this article. An early intervention programme (known as Keyhole), based mainly around Treatment and Education of Autistic and related Communications handicapped CHildren (TEACCH), Picture Exchange Communication System (PECS) and Hanen approaches, was delivered…

Next generation information communication infrastructure and case studies for future power systems

NASA Astrophysics Data System (ADS)

Qiu, Bin

As power industry enters the new century, powerful driving forces, uncertainties and new functions are compelling electric utilities to make dramatic changes in their information communication infrastructure. Expanding network services such as real time measurement and monitoring are also driving the need for more bandwidth in the communication network. These needs will grow further as new remote real-time protection and control applications become more feasible and pervasive. This dissertation addresses two main issues for the future power system information infrastructure: communication network infrastructure and associated power system applications. Optical networks no doubt will become the predominant data transmission media for next generation power system communication. The rapid development of fiber optic network technology poses new challenges in the areas of topology design, network management and real time applications. Based on advanced fiber optic technologies, an all-fiber network is investigated and proposed. The study will cover the system architecture and data exchange protocol aspects. High bandwidth, robust optical networks could provide great opportunities to the power system for better service and efficient operation. In the dissertation, different applications are investigated. One of the typical applications is the SCADA information accessing system. An Internet-based application for the substation automation system will be presented. VLSI (Very Large Scale Integration) technology is also used for one-line diagrams auto-generation. High transition rate and low latency optical network is especially suitable for power system real time control. In the dissertation, a new local area network based Load Shedding Controller (LSC) for isolated power system will be presented. By using PMU (Phasor Measurement Unit) and fiber optic network, an AGE (Area Generation Error) based accurate wide area load shedding scheme will also be proposed. The objective is to shed the load in the limited area with minimum disturbance.

THE INFLUENCE OF MATCHING AND MOTOR-IMITATION ABILITIES ON RAPID ACQUISITION OF MANUAL SIGNS AND EXCHANGE-BASED COMMUNICATIVE RESPONSES

PubMed Central

Gregory, Meagan K; DeLeon, Iser G; Richman, David M

2009-01-01

Establishing a relation between existing skills and acquisition of communicative responses may be useful in guiding selection of alternative communication systems. Matching and motor-imitation skills were assessed for 6 children with developmental disabilities, followed by training to request the same set of preferred items using exchange-based communication and manual signs. Three participants displayed both skills and rapidly acquired both communicative response forms. Three others displayed neither skill; 1 mastered exchange-based responses but not manual signs, and neither of the other 2 easily acquired either response form. PMID:19949531

Modular, Cost-Effective, Extensible Avionics Architecture for Secure, Mobile Communications

NASA Technical Reports Server (NTRS)

Ivancic, William D.

2006-01-01

Current onboard communication architectures are based upon an all-in-one communications management unit. This unit and associated radio systems has regularly been designed as a one-off, proprietary system. As such, it lacks flexibility and cannot adapt easily to new technology, new communication protocols, and new communication links. This paper describes the current avionics communication architecture and provides a historical perspective of the evolution of this system. A new onboard architecture is proposed that allows full use of commercial-off-the-shelf technologies to be integrated in a modular approach thereby enabling a flexible, cost-effective and fully deployable design that can take advantage of ongoing advances in the computer, cryptography, and telecommunications industries.

Modular, Cost-Effective, Extensible Avionics Architecture for Secure, Mobile Communications

NASA Technical Reports Server (NTRS)

Ivancic, William D.

2007-01-01

Current onboard communication architectures are based upon an all-in-one communications management unit. This unit and associated radio systems has regularly been designed as a one-off, proprietary system. As such, it lacks flexibility and cannot adapt easily to new technology, new communication protocols, and new communication links. This paper describes the current avionics communication architecture and provides a historical perspective of the evolution of this system. A new onboard architecture is proposed that allows full use of commercial-off-the-shelf technologies to be integrated in a modular approach thereby enabling a flexible, cost-effective and fully deployable design that can take advantage of ongoing advances in the computer, cryptography, and telecommunications industries.

Pilot-based parametric channel estimation algorithm for DCO-OFDM-based visual light communications

NASA Astrophysics Data System (ADS)

Qian, Xuewen; Deng, Honggui; He, Hailang

2017-10-01

Due to wide modulation bandwidth in optical communication, multipath channels may be non-sparse and deteriorate communication performance heavily. Traditional compressive sensing-based channel estimation algorithm cannot be employed in this kind of situation. In this paper, we propose a practical parametric channel estimation algorithm for orthogonal frequency division multiplexing (OFDM)-based visual light communication (VLC) systems based on modified zero correlation code (ZCC) pair that has the impulse-like correlation property. Simulation results show that the proposed algorithm achieves better performances than existing least squares (LS)-based algorithm in both bit error ratio (BER) and frequency response estimation.

Multi-Spacecraft Autonomous Positioning System

NASA Technical Reports Server (NTRS)

Anzalone, Evan

2015-01-01

As the number of spacecraft in simultaneous operation continues to grow, there is an increased dependency on ground-based navigation support. The current baseline system for deep space navigation utilizes Earth-based radiometric tracking, requiring long-duration observations to perform orbit determination and generate a state update. The age, complexity, and high utilization of the ground assets pose a risk to spacecraft navigation performance. In order to perform complex operations at large distances from Earth, such as extraterrestrial landing and proximity operations, autonomous systems are required. With increasingly complex mission operations, the need for frequent and Earth-independent navigation capabilities is further reinforced. The Multi-spacecraft Autonomous Positioning System (MAPS) takes advantage of the growing interspacecraft communication network and infrastructure to allow for Earth-autonomous state measurements to enable network-based space navigation. A notional concept of operations is given in figure 1. This network is already being implemented and routinely used in Martian communications through the use of the Mars Reconnaissance Orbiter and Mars Odyssey spacecraft as relays for surface assets. The growth of this communications architecture is continued through MAVEN, and future potential commercial Mars telecom orbiters. This growing network provides an initial Marslocal capability for inter-spacecraft communication and navigation. These navigation updates are enabled by cross-communication between assets in the network, coupled with onboard navigation estimation routines to integrate packet travel time to generate ranging measurements. Inter-spacecraft communication allows for frequent state broadcasts and time updates from trusted references. The architecture is a software-based solution, enabling its implementation on a wide variety of current assets, with the operational constraints and measurement accuracy determined by onboard systems.

Bluetooth based chaos synchronization using particle swarm optimization and its applications to image encryption.

PubMed

Yau, Her-Terng; Hung, Tzu-Hsiang; Hsieh, Chia-Chun

2012-01-01

This study used the complex dynamic characteristics of chaotic systems and Bluetooth to explore the topic of wireless chaotic communication secrecy and develop a communication security system. The PID controller for chaos synchronization control was applied, and the optimum parameters of this PID controller were obtained using a Particle Swarm Optimization (PSO) algorithm. Bluetooth was used to realize wireless transmissions, and a chaotic wireless communication security system was developed in the design concept of a chaotic communication security system. The experimental results show that this scheme can be used successfully in image encryption.

Utility of optical facial feature and arm movement tracking systems to enable text communication in critically ill patients who cannot otherwise communicate.

PubMed

Muthuswamy, M B; Thomas, B N; Williams, D; Dingley, J

2014-09-01

Patients recovering from critical illness especially those with critical illness related neuropathy, myopathy, or burns to face, arms and hands are often unable to communicate by writing, speech (due to tracheostomy) or lip reading. This may frustrate both patient and staff. Two low cost movement tracking systems based around a laptop webcam and a laser/optical gaming system sensor were utilised as control inputs for on-screen text creation software and both were evaluated as communication tools in volunteers. Two methods were used to control an on-screen cursor to create short sentences via an on-screen keyboard: (i) webcam-based facial feature tracking, (ii) arm movement tracking by laser/camera gaming sensor and modified software. 16 volunteers with simulated tracheostomy and bandaged arms to simulate communication via gross movements of a burned limb, communicated 3 standard messages using each system (total 48 per system) in random sequence. Ten and 13 minor typographical errors occurred with each system respectively, however all messages were comprehensible. Speed of sentence formation ranged from 58 to 120s with the facial feature tracking system, and 60-160s with the arm movement tracking system. The average speed of sentence formation was 81s (range 58-120) and 104s (range 60-160) for facial feature and arm tracking systems respectively, (P<0.001, 2-tailed independent sample t-test). Both devices may be potentially useful communication aids in patients in general and burns critical care units who cannot communicate by conventional means, due to the nature of their injuries. Copyright © 2014 Elsevier Ltd and ISBI. All rights reserved.

Scientific bases of human-machine communication by voice.

PubMed Central

Schafer, R W

1995-01-01

The scientific bases for human-machine communication by voice are in the fields of psychology, linguistics, acoustics, signal processing, computer science, and integrated circuit technology. The purpose of this paper is to highlight the basic scientific and technological issues in human-machine communication by voice and to point out areas of future research opportunity. The discussion is organized around the following major issues in implementing human-machine voice communication systems: (i) hardware/software implementation of the system, (ii) speech synthesis for voice output, (iii) speech recognition and understanding for voice input, and (iv) usability factors related to how humans interact with machines. PMID:7479802

Space shuttle Ku-band integrated rendezvous radar/communications system study

NASA Technical Reports Server (NTRS)

1976-01-01

The results are presented of work performed on the Space Shuttle Ku-Band Integrated Rendezvous Radar/Communications System Study. The recommendations and conclusions are included as well as the details explaining the results. The requirements upon which the study was based are presented along with the predicted performance of the recommended system configuration. In addition, shuttle orbiter vehicle constraints (e.g., size, weight, power, stowage space) are discussed. The tradeoffs considered and the operation of the recommended configuration are described for an optimized, integrated Ku-band radar/communications system. Basic system tradeoffs, communication design, radar design, antenna tradeoffs, antenna gimbal and drive design, antenna servo design, and deployed assembly packaging design are discussed. The communications and radar performance analyses necessary to support the system design effort are presented. Detailed derivations of the communications thermal noise error, the radar range, range rate, and angle tracking errors, and the communications transmitter distortion parameter effect on crosstalk between the unbalanced quadriphase signals are included.

Address-event-based platform for bioinspired spiking systems

NASA Astrophysics Data System (ADS)

Jiménez-Fernández, A.; Luján, C. D.; Linares-Barranco, A.; Gómez-Rodríguez, F.; Rivas, M.; Jiménez, G.; Civit, A.

2007-05-01

Address Event Representation (AER) is an emergent neuromorphic interchip communication protocol that allows a real-time virtual massive connectivity between huge number neurons, located on different chips. By exploiting high speed digital communication circuits (with nano-seconds timings), synaptic neural connections can be time multiplexed, while neural activity signals (with mili-seconds timings) are sampled at low frequencies. Also, neurons generate "events" according to their activity levels. More active neurons generate more events per unit time, and access the interchip communication channel more frequently, while neurons with low activity consume less communication bandwidth. When building multi-chip muti-layered AER systems, it is absolutely necessary to have a computer interface that allows (a) reading AER interchip traffic into the computer and visualizing it on the screen, and (b) converting conventional frame-based video stream in the computer into AER and injecting it at some point of the AER structure. This is necessary for test and debugging of complex AER systems. In the other hand, the use of a commercial personal computer implies to depend on software tools and operating systems that can make the system slower and un-robust. This paper addresses the problem of communicating several AER based chips to compose a powerful processing system. The problem was discussed in the Neuromorphic Engineering Workshop of 2006. The platform is based basically on an embedded computer, a powerful FPGA and serial links, to make the system faster and be stand alone (independent from a PC). A new platform is presented that allow to connect up to eight AER based chips to a Spartan 3 4000 FPGA. The FPGA is responsible of the network communication based in Address-Event and, at the same time, to map and transform the address space of the traffic to implement a pre-processing. A MMU microprocessor (Intel XScale 400MHz Gumstix Connex computer) is also connected to the FPGA to allow the platform to implement eventbased algorithms to interact to the AER system, like control algorithms, network connectivity, USB support, etc. The LVDS transceiver allows a bandwidth of up to 1.32 Gbps, around ~66 Mega events per second (Mevps).

From Fault-Diagnosis and Performance Recovery of a Controlled System to Chaotic Secure Communication

NASA Astrophysics Data System (ADS)

Hsu, Wen-Teng; Tsai, Jason Sheng-Hong; Guo, Fang-Cheng; Guo, Shu-Mei; Shieh, Leang-San

Chaotic systems are often applied to encryption on secure communication, but they may not provide high-degree security. In order to improve the security of communication, chaotic systems may need to add other secure signals, but this may cause the system to diverge. In this paper, we redesign a communication scheme that could create secure communication with additional secure signals, and the proposed scheme could keep system convergence. First, we introduce the universal state-space adaptive observer-based fault diagnosis/estimator and the high-performance tracker for the sampled-data linear time-varying system with unanticipated decay factors in actuators/system states. Besides, robustness, convergence in the mean, and tracking ability are given in this paper. A residual generation scheme and a mechanism for auto-tuning switched gain is also presented, so that the introduced methodology is applicable for the fault detection and diagnosis (FDD) for actuator and state faults to yield a high tracking performance recovery. The evolutionary programming-based adaptive observer is then applied to the problem of secure communication. Whenever the tracker induces a large control input which might not conform to the input constraint of some physical systems, the proposed modified linear quadratic optimal tracker (LQT) can effectively restrict the control input within the specified constraint interval, under the acceptable tracking performance. The effectiveness of the proposed design methodology is illustrated through tracking control simulation examples.

Communication Systems for Dual Mode Transportation

DOT National Transportation Integrated Search

1974-02-01

A program is underway to develop and demonstrate transportation systems based on vehicles which are capable of automatic operation on special guideways and manual operation on conventional roads. Adequate and reliable communications to and from vehic...

The research of adaptive-exposure on spot-detecting camera in ATP system

NASA Astrophysics Data System (ADS)

Qian, Feng; Jia, Jian-jun; Zhang, Liang; Wang, Jian-Yu

2013-08-01

High precision acquisition, tracking, pointing (ATP) system is one of the key techniques of laser communication. The spot-detecting camera is used to detect the direction of beacon in laser communication link, so that it can get the position information of communication terminal for ATP system. The positioning accuracy of camera decides the capability of laser communication system directly. So the spot-detecting camera in satellite-to-earth laser communication ATP systems needs high precision on target detection. The positioning accuracy of cameras should be better than +/-1μ rad . The spot-detecting cameras usually adopt centroid algorithm to get the position information of light spot on detectors. When the intensity of beacon is moderate, calculation results of centroid algorithm will be precise. But the intensity of beacon changes greatly during communication for distance, atmospheric scintillation, weather etc. The output signal of detector will be insufficient when the camera underexposes to beacon because of low light intensity. On the other hand, the output signal of detector will be saturated when the camera overexposes to beacon because of high light intensity. The calculation accuracy of centroid algorithm becomes worse if the spot-detecting camera underexposes or overexposes, and then the positioning accuracy of camera will be reduced obviously. In order to improve the accuracy, space-based cameras should regulate exposure time in real time according to light intensity. The algorithm of adaptive-exposure technique for spot-detecting camera based on metal-oxide-semiconductor (CMOS) detector is analyzed. According to analytic results, a CMOS camera in space-based laser communication system is described, which utilizes the algorithm of adaptive-exposure to adapting exposure time. Test results from imaging experiment system formed verify the design. Experimental results prove that this design can restrain the reduction of positioning accuracy for the change of light intensity. So the camera can keep stable and high positioning accuracy during communication.

An experimental model of an indigenous BCI based system to help disabled people to communicate

NASA Astrophysics Data System (ADS)

Kabir, Kazi Sadman; Rahman, Chowdhury M. Abid; Farayez, Araf; Ferdous, Mahbuba

2017-12-01

In this paper a Brain Computer Interface (BCI) system has been proposed to help patients suffering from motor disease, paralysis or locked in syndrome to communicate via eye blinking. In this proposed BCI system EEG data is fetched by NeuroSky Headset and then analyzed by the help of WPF (Windows Presentation Foundation) based serial monitor to detect the EEG signal when the eye gives a blink. This detection of eye blinking can be used to select predefined texts and those texts can be converted to speech. The experimental result shows that this system can be used as an effective and efficient tool to communicate through brain.

Using a Computer-based Messaging System at a High School To Increase School/Home Communication.

ERIC Educational Resources Information Center

Burden, Mitzi K.

Minimal communication between school and home was found to contribute to low performance by students at McDuffie High School (South Carolina). This report describes the experience of establishing a computer-based telephone messaging system in the high school and involving parents, teachers, and students in its use. Additional strategies employed…

Cognitive Communications Protocols for SATCOM

DTIC Science & Technology

2017-10-20

both inadvertent Radio Frequency Interference (RFI) and deliberate jammers. Cognitive satellite and space communications strategies based on the... communications protocols for satellite and space communications with possible broad applications in defense, homeland-security as well as consumer...proposed WACR as the basis for future space communication systems that will offer significant benefits to national war‐fighting and peacekeeping

Structural health monitoring system for bridges based on skin-like sensor

NASA Astrophysics Data System (ADS)

Loupos, Konstantinos; Damigos, Yannis; Amditis, Angelos; Gerhard, Reimund; Rychkov, Dmitry; Wirges, Werner; Schulze, Manuel; Lenas, Sotiris-Angelos; Chatziandreoglou, Christos; Malliou, Christina M.; Tsaoussidis, Vassilis; Brady, Ken; Frankenstein, Bernd

2017-09-01

Structural health monitoring activities are of primal importance for managing transport infrastructure, however most SHM methodologies are based on point-based sensors that have limitations in terms of their spatial positioning requirements, cost of development and measurement range. This paper describes the progress on the SENSKIN EC project whose objective is to develop a dielectric-elastomer and micro-electronics-based sensor, formed from a large highly extensible capacitance sensing membrane supported by advanced microelectronic circuitry, for monitoring transport infrastructure bridges. Such a sensor could provide spatial measurements of strain in excess of 10%. The actual sensor along with the data acquisition module, the communication module and power electronics are all integrated into a compact unit, the SENSKIN device, which is energy-efficient, requires simple signal processing and it is easy to install over various surface types. In terms of communication, SENSKIN devices interact with each other to form the SENSKIN system; a fully distributed and autonomous wireless sensor network that is able to self-monitor. SENSKIN system utilizes Delay-/Disruption-Tolerant Networking technologies to ensure that the strain measurements will be received by the base station even under extreme conditions where normal communications are disrupted. This paper describes the architecture of the SENSKIN system and the development and testing of the first SENSKIN prototype sensor, the data acquisition system, and the communication system.

Proportional fair scheduling algorithm based on traffic in satellite communication system

NASA Astrophysics Data System (ADS)

Pan, Cheng-Sheng; Sui, Shi-Long; Liu, Chun-ling; Shi, Yu-Xin

2018-02-01

In the satellite communication network system, in order to solve the problem of low system capacity and user fairness in multi-user access to satellite communication network in the downlink, combined with the characteristics of user data service, an algorithm study on throughput capacity and user fairness scheduling is proposed - Proportional Fairness Algorithm Based on Traffic(B-PF). The algorithm is improved on the basis of the proportional fairness algorithm in the wireless communication system, taking into account the user channel condition and caching traffic information. The user outgoing traffic is considered as the adjustment factor of the scheduling priority and presents the concept of traffic satisfaction. Firstly,the algorithm calculates the priority of the user according to the scheduling algorithm and dispatches the users with the highest priority. Secondly, when a scheduled user is the business satisfied user, the system dispatches the next priority user. The simulation results show that compared with the PF algorithm, B-PF can improve the system throughput, the business satisfaction and fairness.

HL7 and DICOM based integration of radiology departments with healthcare enterprise information systems.

PubMed

Blazona, Bojan; Koncar, Miroslav

2007-12-01

Integration based on open standards, in order to achieve communication and information interoperability, is one of the key aspects of modern health care information systems. However, this requirement represents one of the major challenges for the Information and Communication Technology (ICT) solutions, as systems today use diverse technologies, proprietary protocols and communication standards which are often not interoperable. One of the main producers of clinical information in healthcare settings represent Radiology Information Systems (RIS) that communicate using widely adopted DICOM (Digital Imaging and COmmunications in Medicine) standard, but in very few cases can efficiently integrate information of interest with other systems. In this context we identified HL7 standard as the world's leading medical ICT standard that is envisioned to provide the umbrella for medical data semantic interoperability, which amongst other things represents the cornerstone for the Croatia's National Integrated Healthcare Information System (IHCIS). The aim was to explore the ability to integrate and exchange RIS originated data with Hospital Information Systems based on HL7's CDA (Clinical Document Architecture) standard. We explored the ability of HL7 CDA specifications and methodology to address the need of RIS integration HL7 based healthcare information systems. We introduced the use of WADO service interconnection to IHCIS and finally CDA rendering in widely used Internet explorers. The outcome of our pilot work proves our original assumption of HL7 standard being able to adopt radiology data into the integrated healthcare systems. Uniform DICOM to CDA translation scripts and business processes within IHCIS is desired and cost effective regarding to use of supporting IHCIS services aligned to SOA.

Wireless device monitoring systems and monitoring devices, and associated methods

DOE Office of Scientific and Technical Information (OSTI.GOV)

McCown, Steven H; Derr, Kurt W; Rohde, Kenneth W

Wireless device monitoring systems and monitoring devices include a communications module for receiving wireless communications of a wireless device. Processing circuitry is coupled with the communications module and configured to process the wireless communications to determine whether the wireless device is authorized or unauthorized to be present at the monitored area based on identification information of the wireless device. Methods of monitoring for the presence and identity of wireless devices are also provided.

How to Analyze Verbal and Nonverbal Classroom Communication.

ERIC Educational Resources Information Center

Heger, Herbert K.

Based upon the communications process model of teaching and learning, the Miniaturized Total Interaction Analysis System (Mini-TIA) establishes a conceptual framework for observing symptomatic classroom behaviors. It provides a means for the evaluation of classroom communication. Interpersonal communication is defined as either verbal (using…

Threshold Based Stochastic Resonance for the Binary-Input Ternary-Output Discrete Memoryless Channels

DTIC Science & Technology

2012-05-01

noise (AGN) [1] and [11]. We focus on threshold communication systems due to the underwater environment, noncoherent communication techniques are...the threshold level. In the context of the underwater communications, where noncoherent communication techniques are affected both by noise and

Network security system for health and medical information using smart IC card

NASA Astrophysics Data System (ADS)

Kanai, Yoichi; Yachida, Masuyoshi; Yoshikawa, Hiroharu; Yamaguchi, Masahiro; Ohyama, Nagaaki

1998-07-01

A new network security protocol that uses smart IC cards has been designed to assure the integrity and privacy of medical information in communication over a non-secure network. Secure communication software has been implemented as a library based on this protocol, which is called the Integrated Secure Communication Layer (ISCL), and has been incorporated into information systems of the National Cancer Center Hospitals and the Health Service Center of the Tokyo Institute of Technology. Both systems have succeeded in communicating digital medical information securely.

Bridging the integration gap between imaging and information systems: a uniform data concept for content-based image retrieval in computer-aided diagnosis.

PubMed

Welter, Petra; Riesmeier, Jörg; Fischer, Benedikt; Grouls, Christoph; Kuhl, Christiane; Deserno, Thomas M

2011-01-01

It is widely accepted that content-based image retrieval (CBIR) can be extremely useful for computer-aided diagnosis (CAD). However, CBIR has not been established in clinical practice yet. As a widely unattended gap of integration, a unified data concept for CBIR-based CAD results and reporting is lacking. Picture archiving and communication systems and the workflow of radiologists must be considered for successful data integration to be achieved. We suggest that CBIR systems applied to CAD should integrate their results in a picture archiving and communication systems environment such as Digital Imaging and Communications in Medicine (DICOM) structured reporting documents. A sample DICOM structured reporting template adaptable to CBIR and an appropriate integration scheme is presented. The proposed CBIR data concept may foster the promulgation of CBIR systems in clinical environments and, thereby, improve the diagnostic process.

Bridging the integration gap between imaging and information systems: a uniform data concept for content-based image retrieval in computer-aided diagnosis

PubMed Central

Riesmeier, Jörg; Fischer, Benedikt; Grouls, Christoph; Kuhl, Christiane; Deserno (né Lehmann), Thomas M

2011-01-01

It is widely accepted that content-based image retrieval (CBIR) can be extremely useful for computer-aided diagnosis (CAD). However, CBIR has not been established in clinical practice yet. As a widely unattended gap of integration, a unified data concept for CBIR-based CAD results and reporting is lacking. Picture archiving and communication systems and the workflow of radiologists must be considered for successful data integration to be achieved. We suggest that CBIR systems applied to CAD should integrate their results in a picture archiving and communication systems environment such as Digital Imaging and Communications in Medicine (DICOM) structured reporting documents. A sample DICOM structured reporting template adaptable to CBIR and an appropriate integration scheme is presented. The proposed CBIR data concept may foster the promulgation of CBIR systems in clinical environments and, thereby, improve the diagnostic process. PMID:21672913

Research on APD-based non-line-of-sight UV communication system

NASA Astrophysics Data System (ADS)

Wang, Rongyang; Wang, Ling; Li, Chao; Zhang, Wenjing; Yuan, Yonggang; Xu, Jintong; Zhang, Yan; Li, Xiangyang

2010-10-01

In this paper, specific issues in designing an avalanche photodiode (APD)-based non-line-of-sight (NLOS) ultraviolet (UV) communication system are investigated. A proper wavelength of the UV LEDs and a system configuration should be considered carefully to assure the feasibility of this system. Using the single scattering model, the received optical power at the sensitive area of the APD can be calculated. According to the calculation, it revealed that the scattered ultraviolet signal level was very low; therefore, a post signal processing circuit was necessary. The authors put forward the key components of the circuit based on the compromise between signal bandwidth and gain. The performance of this circuit was evaluated by means of software simulation, and continued work was involved to improve its signal noise ratio (SNR). The transmitter used in this system was 365 nm UV LED array. Strictly speaking, this was not the practical outdoor UV communication system. Since the scattering coefficient of 365 nm UV only drops a little compared with solar blind UV, the research-grade UV communication could be carried out in a darkroom without a great influence. By combining an APD with a compound parabolic concentrator (CPC) optical system, the effective collection area and field of view (FOV) of the detector could be adjusted. Several issues were also raised to improve the performance of UV communication system, including using more powerful UV LEDs and choosing suitable modulation schemes.

C-Speak Aphasia Alternative Communication Program for People with Severe Aphasia: Importance of Executive Functioning and Semantic Knowledge

PubMed Central

Nicholas, Marjorie; Sinotte, Michele P.; Helm-Estabrooks, Nancy

2011-01-01

Learning how to use a computer-based communication system can be challenging for people with severe aphasia even if the system is not word-based. This study explored cognitive and linguistic factors relative to how they affected individual patients’ ability to communicate expressively using C-Speak Aphasia, (CSA), an alternative communication computer program that is primarily picture-based. Ten individuals with severe non-fluent aphasia received at least six months of training with CSA. To assess carryover of training, untrained functional communication tasks (i.e., answering autobiographical questions, describing pictures, making telephone calls, describing a short video, and two writing tasks) were repeatedly probed in two conditions: 1) using CSA in addition to natural forms of communication, and 2) using only natural forms of communication, e.g., speaking, writing, gesturing, drawing. Four of the ten participants communicated more information on selected probe tasks using CSA than they did without the computer. Response to treatment also was examined in relation to baseline measures of non-linguistic executive function skills, pictorial semantic abilities, and auditory comprehension. Only nonlinguistic executive function skills were significantly correlated with treatment response. PMID:21506045

User manual of the CATSS system (version 1.0) communication analysis tool for space station

NASA Technical Reports Server (NTRS)

Tsang, C. S.; Su, Y. T.; Lindsey, W. C.

1983-01-01

The Communication Analysis Tool for the Space Station (CATSS) is a FORTRAN language software package capable of predicting the communications links performance for the Space Station (SS) communication and tracking (C & T) system. An interactive software package was currently developed to run on the DEC/VAX computers. The CATSS models and evaluates the various C & T links of the SS, which includes the modulation schemes such as Binary-Phase-Shift-Keying (BPSK), BPSK with Direct Sequence Spread Spectrum (PN/BPSK), and M-ary Frequency-Shift-Keying with Frequency Hopping (FH/MFSK). Optical Space Communication link is also included. CATSS is a C & T system engineering tool used to predict and analyze the system performance for different link environment. Identification of system weaknesses is achieved through evaluation of performance with varying system parameters. System tradeoff for different values of system parameters are made based on the performance prediction.

C-Band Airport Surface Communications System Standards Development. Phase II Final Report. Volume 1: Concepts of Use, Initial System Requirements, Architecture, and AeroMACS Design Considerations

NASA Technical Reports Server (NTRS)

Hall, Edward; Isaacs, James; Henriksen, Steve; Zelkin, Natalie

2011-01-01

This report is provided as part of ITT s NASA Glenn Research Center Aerospace Communication Systems Technical Support (ACSTS) contract NNC05CA85C, Task 7: New ATM Requirements-Future Communications, C-Band and L-Band Communications Standard Development and was based on direction provided by FAA project-level agreements for New ATM Requirements-Future Communications. Task 7 included two subtasks. Subtask 7-1 addressed C-band (5091- to 5150-MHz) airport surface data communications standards development, systems engineering, test bed and prototype development, and tests and demonstrations to establish operational capability for the Aeronautical Mobile Airport Communications System (AeroMACS). Subtask 7-2 focused on systems engineering and development support of the L-band digital aeronautical communications system (L-DACS). Subtask 7-1 consisted of two phases. Phase I included development of AeroMACS concepts of use, requirements, architecture, and initial high-level safety risk assessment. Phase II builds on Phase I results and is presented in two volumes. Volume I (this document) is devoted to concepts of use, system requirements, and architecture, including AeroMACS design considerations. Volume II describes an AeroMACS prototype evaluation and presents final AeroMACS recommendations. This report also describes airport categorization and channelization methodologies. The purposes of the airport categorization task were (1) to facilitate initial AeroMACS architecture designs and enable budgetary projections by creating a set of airport categories based on common airport characteristics and design objectives, and (2) to offer high-level guidance to potential AeroMACS technology and policy development sponsors and service providers. A channelization plan methodology was developed because a common global methodology is needed to assure seamless interoperability among diverse AeroMACS services potentially supplied by multiple service providers.

Design and implementation of an Internet based effective controlling and monitoring system with wireless fieldbus communications technologies for process automation--an experimental study.

PubMed

Cetinceviz, Yucel; Bayindir, Ramazan

2012-05-01

The network requirements of control systems in industrial applications increase day by day. The Internet based control system and various fieldbus systems have been designed in order to meet these requirements. This paper describes an Internet based control system with wireless fieldbus communication designed for distributed processes. The system was implemented as an experimental setup in a laboratory. In industrial facilities, the process control layer and the distance connection of the distributed control devices in the lowest levels of the industrial production environment are provided with fieldbus networks. In this paper, the Internet based control system that will be able to meet the system requirements with a new-generation communication structure, which is called wired/wireless hybrid system, has been designed on field level and carried out to cover all sectors of distributed automation, from process control, to distributed input/output (I/O). The system has been accomplished by hardware structure with a programmable logic controller (PLC), a communication processor (CP) module, two industrial wireless modules and a distributed I/O module, Motor Protection Package (MPP) and software structure with WinCC flexible program used for the screen of Scada (Supervisory Control And Data Acquisition), SIMATIC MANAGER package program ("STEP7") used for the hardware and network configuration and also for downloading control program to PLC. Copyright © 2012 ISA. Published by Elsevier Ltd. All rights reserved.

Telesign: a videophone system for sign language distant communication

NASA Astrophysics Data System (ADS)

Mozelle, Gerard; Preteux, Francoise J.; Viallet, Jean-Emmanuel

1998-09-01

This paper presents a low bit rate videophone system for deaf people communicating by means of sign language. Classic video conferencing systems have focused on head and shoulders sequences which are not well-suited for sign language video transmission since hearing impaired people also use their hands and arms to communicate. To address the above-mentioned functionality, we have developed a two-step content-based video coding system based on: (1) A segmentation step. Four or five video objects (VO) are extracted using a cooperative approach between color-based and morphological segmentation. (2) VO coding are achieved by using a standardized MPEG-4 video toolbox. Results of encoded sign language video sequences, presented for three target bit rates (32 kbits/s, 48 kbits/s and 64 kbits/s), demonstrate the efficiency of the approach presented in this paper.

Student Involvement Through a Communication System

ERIC Educational Resources Information Center

Bromley, Phillip

1975-01-01

The communication system outlined in this article rests on the assumption that schools can operate on a rational, well-ordered, democratic base of shared involvement. Idealistic? Many schools have instituted or are interested in instituting a similar plan. (Editor)

Simulation platform of LEO satellite communication system based on OPNET

NASA Astrophysics Data System (ADS)

Zhang, Yu; Zhang, Yong; Li, Xiaozhuo; Wang, Chuqiao; Li, Haihao

2018-02-01

For the purpose of verifying communication protocol in the low earth orbit (LEO) satellite communication system, an Optimized Network Engineering Tool (OPNET) based simulation platform is built. Using the three-layer modeling mechanism, the network model, the node model and the process model of the satellite communication system are built respectively from top to bottom, and the protocol will be implemented by finite state machine and Proto-C language. According to satellite orbit parameters, orbit files are generated via Satellite Tool Kit (STK) and imported into OPNET, and the satellite nodes move along their orbits. The simulation platform adopts time-slot-driven mode, divides simulation time into continuous time slots, and allocates slot number for each time slot. A resource allocation strategy is simulated on this platform, and the simulation results such as resource utilization rate, system throughput and packet delay are analyzed, which indicate that this simulation platform has outstanding versatility.

Registering Names and Addresses for Information Technology.

ERIC Educational Resources Information Center

Knapp, Arthur A.

The identification of administrative authorities and the development of associated procedures for registering and accessing names and addresses of communications data systems are considered in this paper. It is noted that, for data communications systems using standards based on the Open Systems Interconnection (OSI) Reference Model specified by…

Research on target information optics communications transmission characteristic and performance in multi-screens testing system

NASA Astrophysics Data System (ADS)

Li, Hanshan

2016-04-01

To enhance the stability and reliability of multi-screens testing system, this paper studies multi-screens target optical information transmission link properties and performance in long-distance, sets up the discrete multi-tone modulation transmission model based on geometric model of laser multi-screens testing system and visible light information communication principle; analyzes the electro-optic and photoelectric conversion function of sender and receiver in target optical information communication system; researches target information transmission performance and transfer function of the generalized visible-light communication channel; found optical information communication transmission link light intensity space distribution model and distribution function; derives the SNR model of information transmission communication system. Through the calculation and experiment analysis, the results show that the transmission error rate increases with the increment of transmission rate in a certain channel modulation depth; when selecting the appropriate transmission rate, the bit error rate reach 0.01.

Implementation of a Publish-Subscribe Protocol in Microgrid Islanding and Resynchronization with Self-Discovery

DOE Office of Scientific and Technical Information (OSTI.GOV)

Starke, M.; Herron, A.; King, D.

Communications systems and protocols are becoming second nature to utilities operating distribution systems. Traditionally, centralized communication approaches are often used, while recently in microgrid applications, distributed communication and control schema emerge offering several advantages such as improved system reliability, plug-and-play operation and distributed intelligence. Still, operation and control of microgrids including distributed communication schema have been less of a discussion in the literature. To address the challenge of multiple-inverter microgrid synchronization, a publish-subscribe protocol based, Data Distribution Service (DDS), communication schema for microgrids is proposed in this paper. The communication schema is discussed in details for individual devices such asmore » generators, photovoltaic systems, energy storage systems, microgrid point of common coupling switch, and supporting applications. In conclusion, islanding and resynchronization of a microgrid are demonstrated on a test-bed utilizing this schema.« less

Implementation of a Publish-Subscribe Protocol in Microgrid Islanding and Resynchronization with Self-Discovery

DOE PAGES

Starke, M.; Herron, A.; King, D.; ...

2017-08-24

Communications systems and protocols are becoming second nature to utilities operating distribution systems. Traditionally, centralized communication approaches are often used, while recently in microgrid applications, distributed communication and control schema emerge offering several advantages such as improved system reliability, plug-and-play operation and distributed intelligence. Still, operation and control of microgrids including distributed communication schema have been less of a discussion in the literature. To address the challenge of multiple-inverter microgrid synchronization, a publish-subscribe protocol based, Data Distribution Service (DDS), communication schema for microgrids is proposed in this paper. The communication schema is discussed in details for individual devices such asmore » generators, photovoltaic systems, energy storage systems, microgrid point of common coupling switch, and supporting applications. In conclusion, islanding and resynchronization of a microgrid are demonstrated on a test-bed utilizing this schema.« less

Robust Control Techniques Enabling Duty Cycle Experiments Utilizing a 6-DOF Crewstation Motion Base, a Full Scale Combat Hybrid Electric Power System, and Long Distance Internet Communications

DTIC Science & Technology

2006-11-10

Electric Power System, and Long Distance Internet Communications Marc Compere , Jarrett Goodell, Miguel Simon, Wilford Smith Science Applications...System, and Long Distance Internet Communication 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Marc Compere ...Systems Symposium, NDIA, Traverse City, MI, June 2006. 3. Miguel Simon, Marc Compere , Thomas Connolly, Charles Lars, Wilford Smith, Mark Brudnak, "Hybrid

Optimal Power Allocation Strategy in a Joint Bistatic Radar and Communication System Based on Low Probability of Intercept

PubMed Central

Wang, Fei; Salous, Sana; Zhou, Jianjiang

2017-01-01

In this paper, we investigate a low probability of intercept (LPI)-based optimal power allocation strategy for a joint bistatic radar and communication system, which is composed of a dedicated transmitter, a radar receiver, and a communication receiver. The joint system is capable of fulfilling the requirements of both radar and communications simultaneously. First, assuming that the signal-to-noise ratio (SNR) corresponding to the target surveillance path is much weaker than that corresponding to the line of sight path at radar receiver, the analytically closed-form expression for the probability of false alarm is calculated, whereas the closed-form expression for the probability of detection is not analytically tractable and is approximated due to the fact that the received signals are not zero-mean Gaussian under target presence hypothesis. Then, an LPI-based optimal power allocation strategy is presented to minimize the total transmission power for information signal and radar waveform, which is constrained by a specified information rate for the communication receiver and the desired probabilities of detection and false alarm for the radar receiver. The well-known bisection search method is employed to solve the resulting constrained optimization problem. Finally, numerical simulations are provided to reveal the effects of several system parameters on the power allocation results. It is also demonstrated that the LPI performance of the joint bistatic radar and communication system can be markedly improved by utilizing the proposed scheme. PMID:29186850

Optimal Power Allocation Strategy in a Joint Bistatic Radar and Communication System Based on Low Probability of Intercept.

PubMed

Shi, Chenguang; Wang, Fei; Salous, Sana; Zhou, Jianjiang

2017-11-25

In this paper, we investigate a low probability of intercept (LPI)-based optimal power allocation strategy for a joint bistatic radar and communication system, which is composed of a dedicated transmitter, a radar receiver, and a communication receiver. The joint system is capable of fulfilling the requirements of both radar and communications simultaneously. First, assuming that the signal-to-noise ratio (SNR) corresponding to the target surveillance path is much weaker than that corresponding to the line of sight path at radar receiver, the analytically closed-form expression for the probability of false alarm is calculated, whereas the closed-form expression for the probability of detection is not analytically tractable and is approximated due to the fact that the received signals are not zero-mean Gaussian under target presence hypothesis. Then, an LPI-based optimal power allocation strategy is presented to minimize the total transmission power for information signal and radar waveform, which is constrained by a specified information rate for the communication receiver and the desired probabilities of detection and false alarm for the radar receiver. The well-known bisection search method is employed to solve the resulting constrained optimization problem. Finally, numerical simulations are provided to reveal the effects of several system parameters on the power allocation results. It is also demonstrated that the LPI performance of the joint bistatic radar and communication system can be markedly improved by utilizing the proposed scheme.

COMPIC--How To Create and Order Personalized Communication Layouts for Your Clients.

ERIC Educational Resources Information Center

Snelleman, Johanna; Dunne, Louise

The COMPIC Development Association, an organization based in Victoria, Australia, has developed techniques for publishing pictographic materials for use by individuals with severe communication impairments. The COMPIC (Computer Pictographs for Communication) system comprises a method of electronically publishing customized communication aids and…

Adaptive synchronisation of memristor-based neural networks with leakage delays and applications in chaotic masking secure communication

NASA Astrophysics Data System (ADS)

Liu, Jian; Xu, Rui

2018-04-01

Chaotic synchronisation has caused extensive attention due to its potential application in secure communication. This paper is concerned with the problem of adaptive synchronisation for two different kinds of memristor-based neural networks with time delays in leakage terms. By applying set-valued maps and differential inclusions theories, synchronisation criteria are obtained via linear matrix inequalities technique, which guarantee drive system being synchronised with response system under adaptive control laws. Finally, a numerical example is given to illustrate the feasibility of our theoretical results, and two schemes for secure communication are introduced based on chaotic masking method.

Design considerations for implementation of large scale automatic meter reading systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mak, S.; Radford, D.

1995-01-01

This paper discusses the requirements imposed on the design of an AMR system expected to serve a large (> 1 million) customer base spread over a large geographical area. Issues such as system throughput response time, and multi-application expendability are addressed, all of which are intimately dependent on the underlying communication system infrastructure, the local geography, the customer base, and the regulatory environment. A methodology for analysis, assessment, and design of large systems is presented. For illustration, two communication systems -- a low power RF/PLC system and a power frequency carrier system -- are analyzed and discussed.

Fiber-Optic Network Architectures for Onboard Avionics Applications Investigated

NASA Technical Reports Server (NTRS)

Nguyen, Hung D.; Ngo, Duc H.

2003-01-01

This project is part of a study within the Advanced Air Transportation Technologies program undertaken at the NASA Glenn Research Center. The main focus of the program is the improvement of air transportation, with particular emphasis on air transportation safety. Current and future advances in digital data communications between an aircraft and the outside world will require high-bandwidth onboard communication networks. Radiofrequency (RF) systems, with their interconnection network based on coaxial cables and waveguides, increase the complexity of communication systems onboard modern civil and military aircraft with respect to weight, power consumption, and safety. In addition, safety and reliability concerns from electromagnetic interference between the RF components embedded in these communication systems exist. A simple, reliable, and lightweight network that is free from the effects of electromagnetic interference and capable of supporting the broadband communications needs of future onboard digital avionics systems cannot be easily implemented using existing coaxial cable-based systems. Fiber-optical communication systems can meet all these challenges of modern avionics applications in an efficient, cost-effective manner. The objective of this project is to present a number of optical network architectures for onboard RF signal distribution. Because of the emergence of a number of digital avionics devices requiring high-bandwidth connectivity, fiber-optic RF networks onboard modern aircraft will play a vital role in ensuring a low-noise, highly reliable RF communication system. Two approaches are being used for network architectures for aircraft onboard fiber-optic distribution systems: a hybrid RF-optical network and an all-optical wavelength division multiplexing (WDM) network.

High-Level Data-Abstraction System

NASA Technical Reports Server (NTRS)

Fishwick, P. A.

1986-01-01

Communication with data-base processor flexible and efficient. High Level Data Abstraction (HILDA) system is three-layer system supporting data-abstraction features of Intel data-base processor (DBP). Purpose of HILDA establishment of flexible method of efficiently communicating with DBP. Power of HILDA lies in its extensibility with regard to syntax and semantic changes. HILDA's high-level query language readily modified. Offers powerful potential to computer sites where DBP attached to DEC VAX-series computer. HILDA system written in Pascal and FORTRAN 77 for interactive execution.

The wireless data acquisition system based on Bluetooth

NASA Astrophysics Data System (ADS)

Cheng, En; Xu, Xiao-na; Wu, Si-long

2013-03-01

Bluetooth is one of the wireless communication technology, which is developing rapidly in recent years. As a result of low cost and short distance, Bluetooth can set up a special connection for portable electronic devices and stationary electronic equipment communication environment. The paper studies a data acquisition system based on Bluetooth. The system can collect the angle of motor rotation and send it to the Receiver through the Bluetooth. The results show that the system can be run normal.[1

Nanoscale molecular communication networks: a game-theoretic perspective

NASA Astrophysics Data System (ADS)

Jiang, Chunxiao; Chen, Yan; Ray Liu, K. J.

2015-12-01

Currently, communication between nanomachines is an important topic for the development of novel devices. To implement a nanocommunication system, diffusion-based molecular communication is considered as a promising bio-inspired approach. Various technical issues about molecular communications, including channel capacity, noise and interference, and modulation and coding, have been studied in the literature, while the resource allocation problem among multiple nanomachines has not been well investigated, which is a very important issue since all the nanomachines share the same propagation medium. Considering the limited computation capability of nanomachines and the expensive information exchange cost among them, in this paper, we propose a game-theoretic framework for distributed resource allocation in nanoscale molecular communication systems. We first analyze the inter-symbol and inter-user interference, as well as bit error rate performance, in the molecular communication system. Based on the interference analysis, we formulate the resource allocation problem as a non-cooperative molecule emission control game, where the Nash equilibrium is found and proved to be unique. In order to improve the system efficiency while guaranteeing fairness, we further model the resource allocation problem using a cooperative game based on the Nash bargaining solution, which is proved to be proportionally fair. Simulation results show that the Nash bargaining solution can effectively ensure fairness among multiple nanomachines while achieving comparable social welfare performance with the centralized scheme.

The Telecommunications and Data Acquisition Report

NASA Technical Reports Server (NTRS)

Posner, E. C. (Editor)

1991-01-01

This quarterly reports on space communications, radio navigation, radio science, and ground based radio and radar astronomy in connection with the Deep Space Network (DSN) in planning, supporting research and technology, implementation, and in operations. Also included is standards activity at JPL for space data and information systems and DSN work. Specific areas of research are: Tracking and ground based navigation; Spacecraft and ground communications; Station control and system technology; DSN Systems Implementation; and DSN Operations.

Hybrid Communication Architectures for Distributed Smart Grid Applications

DOE PAGES

Zhang, Jianhua; Hasandka, Adarsh; Wei, Jin; ...

2018-04-09

Wired and wireless communications both play an important role in the blend of communications technologies necessary to enable future smart grid communications. Hybrid networks exploit independent mediums to extend network coverage and improve performance. However, whereas individual technologies have been applied in simulation networks, as far as we know there is only limited attention that has been paid to the development of a suite of hybrid communication simulation models for the communications system design. Hybrid simulation models are needed to capture the mixed communication technologies and IP address mechanisms in one simulation. To close this gap, we have developed amore » suite of hybrid communication system simulation models to validate the critical system design criteria for a distributed solar Photovoltaic (PV) communications system, including a single trip latency of 300 ms, throughput of 9.6 Kbps, and packet loss rate of 1%. In conclusion, the results show that three low-power wireless personal area network (LoWPAN)-based hybrid architectures can satisfy three performance metrics that are critical for distributed energy resource communications.« less

Hybrid Communication Architectures for Distributed Smart Grid Applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Jianhua; Hasandka, Adarsh; Wei, Jin

Wired and wireless communications both play an important role in the blend of communications technologies necessary to enable future smart grid communications. Hybrid networks exploit independent mediums to extend network coverage and improve performance. However, whereas individual technologies have been applied in simulation networks, as far as we know there is only limited attention that has been paid to the development of a suite of hybrid communication simulation models for the communications system design. Hybrid simulation models are needed to capture the mixed communication technologies and IP address mechanisms in one simulation. To close this gap, we have developed amore » suite of hybrid communication system simulation models to validate the critical system design criteria for a distributed solar Photovoltaic (PV) communications system, including a single trip latency of 300 ms, throughput of 9.6 Kbps, and packet loss rate of 1%. In conclusion, the results show that three low-power wireless personal area network (LoWPAN)-based hybrid architectures can satisfy three performance metrics that are critical for distributed energy resource communications.« less

A network control concept for the 30/20 GHz communication system baseband processor

NASA Technical Reports Server (NTRS)

Sabourin, D. J.; Hay, R. E.

1982-01-01

The architecture and system design for a satellite-switched TDMA communication system employing on-board processing was developed by Motorola for NASA's Lewis Research Center. The system design is based on distributed processing techniques that provide extreme flexibility in the selection of a network control protocol without impacting the satellite or ground terminal hardware. A network control concept that includes system synchronization and allows burst synchronization to occur within the system operational requirement is described. This concept integrates the tracking and control links with the communication links via the baseband processor, resulting in an autonomous system operational approach.

Techniques Analysis of the Interference Suppression Algorithm in Broadband Aeronautical Multi-carrier Communication System

NASA Astrophysics Data System (ADS)

Li, Dong-xia; Ye, Qian-wen

Out-of-band radiation suppression algorithm must be used efficiently for broadband aeronautical communication system in order not to interfere the operation of the existing systems in aviation L-Band. Based on the simple introduction of the broadband aeronautical multi-carrier communication (B-AMC) system model, several sidelobe suppression techniques in orthogonal frequency multiplexing (OFDM) system are presented and analyzed so as to find a suitable algorithm for B-AMC system in this paper. Simulation results show that raise-cosine function windowing can suppress the out-of-band radiation of B-AMC system effectively.

Communications for UAS Integration in the NAS Phase 2 Satellite Communications and Terrestrial Extension

NASA Technical Reports Server (NTRS)

Griner, Jim; Kerczewski, Bob

2017-01-01

In order to provide for the safe integration of unmanned aircraft systems (UAS) into the National Airspace System, the command and control communications link connecting the ground-based pilot with the unmanned aircraft must be highly reliable and robust, with national and international standards to enable interoperability and certification. Both line-of-sight (LOS) links using terrestrial-based communications and beyond-line-of-sight (BLOS) links using satellite communications, supported by national and international standards, are required for integrated UAS operations. The National Aeronautics and Space Administration (NASA) has undertaken an extensive technology development and test program in order to provide the required technical data needed to enable C2 standards development. NASAs UAS Integration in the National Airspace System (NAS), or UAS in the NAS Project, included as a major element the Command and Control Communications (C2) Subproject, based at NASAs Glenn Research Center. The successful first phase of the C2 Subproject, completed during 2012-2016, focused primarily on line-of-sight communications. Accomplishments included air-ground channel propagation characterization and modeling; CNPC prototype radio development; CNPC radio flight testing; satellite communications spectrum study and interference analysis; and development of C2 LOS communications standards development. The second phase of the C2 Subproject will focus primarily on beyond-line-of-sight communications, although a follow-on activity for terrestrial LOS communications, known as Terrestrial Extension, is also included. In addition to the terrestrial element, Phase 2 also includes technology development and testing activities for Ka-Band BLOS C2 Satellite Communications; Ku-Band BLOS C2 Satellite Communications; Ku-Band Interference and Propagation; and C-Band Satellite Communications. This paper will provide brief overviews of the C2 Subproject and its Phase I accomplishments, followed by a description of the plans for the C2 Subproject Phase 2.

Communications for UAS Integration in the NAS Phase 2 - Satellite Communications and Terrestrial Extension

NASA Technical Reports Server (NTRS)

Griner, James H.; Kerczewski, Robert J.

2017-01-01

In order to provide for the safe integration of unmanned aircraft systems (UAS) into the National Airspace System, the command and control communications link connecting the ground-based pilot with the unmanned aircraft must be highly reliable and robust, with national and international standards to enable interoperability and certification. Both line-of-sight (LOS) links using terrestrial-based communications and beyond-line-of-sight (BLOS) links using satellite communications, supported by national and international standards, are required for integrated UAS operations. The National Aeronautics and Space Administration (NASA) has undertaken an extensive technology development and test program in order to provide the required technical data needed to enable C2 standards development. NASAs UAS Integration in the National Airspace System (NAS), or UAS in the NAS Project, included as a major element the Command and Control Communications (C2) Subproject, based at NASAs Glenn Research Center. The successful first phase of the C2 Subproject, completed during 2012-2016, focused primarily on line-of-sight communications. Accomplishments included air-ground channel propagation characterization and modeling; CNPC prototype radio development; CNPC radio flight testing; satellite communications spectrum study and interference analysis; and development of C2 LOS communications standards development. The second phase of the C2 Subproject will focus primarily on beyond-line-of-sight communications, although a follow-on activity for terrestrial LOS communications, known as Terrestrial Extension, is also included. In addition to the terrestrial element, Phase 2 also includes technology development and testing activities for Ka-Band BLOS C2 Satellite Communications; Ku-Band BLOS C2 Satellite Communications; Ku-Band Interference and Propagation; and C-Band Satellite Communications. This paper will provide brief overviews of the C2 Subproject and its Phase I accomplishments, followed by a description of the plans for the C2 Subproject Phase 2.

Active tracking system for visible light communication using a GaN-based micro-LED and NRZ-OOK.

PubMed

Lu, Zhijian; Tian, Pengfei; Chen, Hong; Baranowski, Izak; Fu, Houqiang; Huang, Xuanqi; Montes, Jossue; Fan, Youyou; Wang, Hongyi; Liu, Xiaoyan; Liu, Ran; Zhao, Yuji

2017-07-24

Visible light communication (VLC) holds the promise of a high-speed wireless network for indoor applications and competes with 5G radio frequency (RF) system. Although the breakthrough of gallium nitride (GaN) based micro-light-emitting-diodes (micro-LEDs) increases the -3dB modulation bandwidth exceptionally from tens of MHz to hundreds of MHz, the light collected onto a fast photo receiver drops dramatically, which determines the signal to noise ratio (SNR) of VLC. To fully implement the practical high data-rate VLC link enabled by a GaN-based micro-LED, it requires focusing optics and a tracking system. In this paper, we demonstrate an active on-chip tracking system for VLC using a GaN-based micro-LED and none-return-to-zero on-off keying (NRZ-OOK). Using this novel technique, the field of view (FOV) was enlarged to 120° and data rates up to 600 Mbps at a bit error rate (BER) of 2.1×10 -4 were achieved without manual focusing. This paper demonstrates the establishment of a VLC physical link that shows enhanced communication quality by orders of magnitude, making it optimized for practical communication applications.

Ray-based approach to integrated 3D visual communication

NASA Astrophysics Data System (ADS)

Naemura, Takeshi; Harashima, Hiroshi

2001-02-01

For a high sense of reality in the next-generation communications, it is very important to realize three-dimensional (3D) spatial media, instead of existing 2D image media. In order to comprehensively deal with a variety of 3D visual data formats, the authors first introduce the concept of "Integrated 3D Visual Communication," which reflects the necessity of developing a neutral representation method independent of input/output systems. Then, the following discussions are concentrated on the ray-based approach to this concept, in which any visual sensation is considered to be derived from a set of light rays. This approach is a simple and straightforward to the problem of how to represent 3D space, which is an issue shared by various fields including 3D image communications, computer graphics, and virtual reality. This paper mainly presents the several developments in this approach, including some efficient methods of representing ray data, a real-time video-based rendering system, an interactive rendering system based on the integral photography, a concept of virtual object surface for the compression of tremendous amount of data, and a light ray capturing system using a telecentric lens. Experimental results demonstrate the effectiveness of the proposed techniques.

Non-flickering 100 m RGB visible light communication transmission based on a CMOS image sensor.

PubMed

Chow, Chi-Wai; Shiu, Ruei-Jie; Liu, Yen-Chun; Liu, Yang; Yeh, Chien-Hung

2018-03-19

We demonstrate a non-flickering 100 m long-distance RGB visible light communication (VLC) transmission based on a complementary-metal-oxide-semiconductor (CMOS) camera. Experimental bit-error rate (BER) measurements under different camera ISO values and different transmission distances are evaluated. Here, we also experimentally reveal that the rolling shutter effect- (RSE) based VLC system cannot work at long distance transmission, and the under-sampled modulation- (USM) based VLC system is a good choice.

Design of the Wind Tunnel Model Communication Controller Board. Degree awarded by Christopher Newport Univ. on Dec. 1998

NASA Technical Reports Server (NTRS)

Wilson, William C.

1999-01-01

The NASA Langley Research Center's Wind Tunnel Reinvestment project plans to shrink the existing data acquisition electronics to fit inside a wind tunnel model. Space limitations within a model necessitate a distributed system of Application Specific Integrated Circuits (ASICs) rather than a centralized system based on PC boards. This thesis will focus on the design of the prototype of the communication Controller board. A portion of the communication Controller board is to be used as the basis of an ASIC design. The communication Controller board will communicate between the internal model modules and the external data acquisition computer. This board is based around an Field Programmable Gate Array (FPGA), to allow for reconfigurability. In addition to the FPGA, this board contains buffer Random Access Memory (RAM), configuration memory (EEPROM), drivers for the communications ports, and passive components.

A satellite system for land-mobile communications in Europe

NASA Technical Reports Server (NTRS)

Bartholome, P.; Rogard, R.

1988-01-01

There exists a great unsatisified demand for land mobile communications in Europe, particularly in sectors of business activity such as the road transport industry. This demand could best be satisfied by means of satellite-based private networks providing voice and data communications in a hub configuration. The potential market is estimated to encompass several hundred thousand road vehicles and the transmission capacity required would be several thousand channels. ESA is currently demonstrating the potential of satellite communications for this type of application, using a system called PRODAT. System studies are being performed with the aim of defining the architecture of a regional satellite system for Europe.

Progress on the Development of the UAS C2 Link and Supporting Spectrum - from LOS to BLOS

NASA Technical Reports Server (NTRS)

Kerczewski, Robert J.; Griner, James H.; Bishop, William D.; Matolak, David W.; Wilson, Jeffrey D.

2017-01-01

In order to provide for the safe integration of unmanned aircraft systems (UAS) into the National Airspace System, the control and non-payload communications (CNPC) link connecting the ground-based pilot with the unmanned aircraft must be highly reliable and robust, based upon standards that enable certification. Both line-of-sight (LOS) links using terrestrial-based communications and beyond-line-of-sight (BLOS) links using satellite communications are required to support UAS operations. The development of standards has been undertaken by RTCA Special Committee 228 (SC-228), with supporting technical data developed by NASA under the UAS in the National Airspace (NAS) Project. As a result of this work minimum operational performance standards (MOPS) have been completed and published for the LOS CNPC system. The second phase of work, for both NASA and RTCA involves the BLOS CNPC systems. The development of technical data to support MOPS development for UAS BLOS satellite-based CNPC links has now been initiated by NASA, and RTCA SC-228 has organized itself to begin the MOPS development process. This paper will provide an overview of the work that has been completed to date by the Communications Subproject in support of LOS C2 communications for UAS followed by an update of plans and progress for the BLOS phase of the project, with the focus on the UAS C2 spectrum aspects.

Near Sun Free-Space Optical Communications from Space

NASA Technical Reports Server (NTRS)

Biswas, Abhijit; Khatri, F.; Boroson, D.

2006-01-01

Free-space optical communications offers expanded data return capacity, from probes distributed throughout the solar system and beyond. Space-borne and Earth-based optical transceivers used for communicating optically, will periodically encounter near Sun pointing. This will result in an increase in the scattered background light flux, often contributing to degraded link performance. The varying duration of near Sun pointing link operations relative to the location of space-probes, is discussed in this paper. The impact of near Sun pointing on link performance for a direct detection photon-counting communications system is analyzed for both ground- and space-based Earth receivers. Finally, impact of near Sun pointing on spaceborne optical transceivers is discussed.

The PLATO IV Communications System.

ERIC Educational Resources Information Center

Sherwood, Bruce Arne; Stifle, Jack

The PLATO IV computer-based educational system contains its own communications hardware and software for operating plasma-panel graphics terminals. Key echoing is performed by the central processing unit: every key pressed at a terminal passes through the entire system before anything appears on the terminal's screen. Each terminal is guaranteed…

Integrated communications and optical navigation system

NASA Astrophysics Data System (ADS)

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

2013-12-01

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.

Near field communication (NFC) model for arduino uno based security systems office system

NASA Astrophysics Data System (ADS)

Chairunnas, A.; Abdurrasyid, I.

2018-03-01

Currently, many offices or companies that start growing rapidly in a company or office should have a very limited room to enter only people entitled to enter the room and use the facilities contained in it, for example, Files in it must have many files and documents very important because to reduce the abuse of files and irresponsible person. Because it will be made room door security system by using Near Field Communication on android smartphone. Software used is Arduino IDE. The tools used in this system are Arduino Uno R3, NFC shield, pear sensor, bell, led, servo, 16 × 2 LCD, and Near Field Communication (NFC) in android smartphone. This system runs based on 2 inputs of a new technology that is Near Field Communication (NFC) in android smartphone. And also use pear sensor to detect unauthorized person entering the room. If the correct password is entered then the door will open and the pear sensor will light off if wrong then the bell will light up.

Imbalance detection in a manufacturing system: An agent-based model usage

NASA Astrophysics Data System (ADS)

Shevchuk, G. K.; Zvereva, O. M.; Medvedev, M. A.

2017-11-01

This paper delivers the results of the research work targeted at communications in a manufacturing system. A computer agent-based model which simulates manufacturing system functioning has been engineered. The system lifecycle consists of two recursively repeated stages: a communication stage and a production stage. Model data sets were estimated with the static Leontief's equilibrium equation usage. In experiments relationships between the manufacturing system lifecycle time and conditions of equilibrium violations have been identified. The research results are to be used to propose violation negative influence compensation methods.

C-Band Airport Surface Communications System Standards Development. Phase II Final Report. Volume 2: Test Bed Performance Evaluation and Final AeroMACS Recommendations

NASA Technical Reports Server (NTRS)

Hall, Edward; Magner, James

2011-01-01

This report is provided as part of ITT s NASA Glenn Research Center Aerospace Communication Systems Technical Support (ACSTS) contract NNC05CA85C, Task 7: New ATM Requirements-Future Communications, C-Band and L-Band Communications Standard Development and was based on direction provided by FAA project-level agreements for New ATM Requirements-Future Communications. Task 7 included two subtasks. Subtask 7-1 addressed C-band (5091- to 5150-MHz) airport surface data communications standards development, systems engineering, test bed and prototype development, and tests and demonstrations to establish operational capability for the Aeronautical Mobile Airport Communications System (AeroMACS). Subtask 7-2 focused on systems engineering and development support of the L-band digital aeronautical communications system (L-DACS). Subtask 7-1 consisted of two phases. Phase I included development of AeroMACS concepts of use, requirements, architecture, and initial high-level safety risk assessment. Phase II builds on Phase I results and is presented in two volumes. Volume I is devoted to concepts of use, system requirements, and architecture, including AeroMACS design considerations. Volume II (this document) describes an AeroMACS prototype evaluation and presents final AeroMACS recommendations. This report also describes airport categorization and channelization methodologies. The purposes of the airport categorization task were (1) to facilitate initial AeroMACS architecture designs and enable budgetary projections by creating a set of airport categories based on common airport characteristics and design objectives, and (2) to offer high-level guidance to potential AeroMACS technology and policy development sponsors and service providers. A channelization plan methodology was developed because a common global methodology is needed to assure seamless interoperability among diverse AeroMACS services potentially supplied by multiple service providers.

A Study on Cognitive Radio Coexisting with Cellular Systems

NASA Astrophysics Data System (ADS)

Tandai, Tomoya; Horiguchi, Tomoya; Deguchi, Noritaka; Tomizawa, Takeshi; Tomioka, Tazuko

Cognitive Radios (CRs) are expected to perform more significant role in the view of efficient utilization of the spectrum resources in the future wireless communication networks. In this paper, a cognitive radio coexisting with cellular systems is proposed. In the case that a cellular system adopts Frequency Division Duplex (FDD) as a multiplexing scheme, the proposed CR terminals communicate in local area on uplink channels of the cellular system with transmission powers that don't interfere with base stations of the cellular system. Alternatively, in the case that a cellular system adopts Time Division Duplex (TDD), the CR terminals communicate on uplink slots of the cellular system. However if mobile terminals in the cellular system are near the CR network, uplink signals from the mobile terminals may interfere with the CR communications. In order to avoid interference from the mobile terminals, the CR terminal performs carrier sense during a beginning part of uplink slot, and only when the level of detected signal is below a threshold, then the CR terminal transmits a signal during the remained period of the uplink slot. In this paper, both the single carrier CR network that uses one frequency channel of the cellular system and the multicarrier CR network that uses multiple frequency channels of the cellular system are considered. The probabilities of successful CR communications, the average throughputs of the CR communications according to the positions of the CR network, and the interference levels from cognitive radio network to base stations of the cellular system are evaluated in the computer simulation then the effectiveness of the proposed network is clarified.

ESA personal communications and digital audio broadcasting systems based on non-geostationary satellites

NASA Technical Reports Server (NTRS)

Logalbo, P.; Benedicto, J.; Viola, R.

1993-01-01

Personal Communications and Digital Audio Broadcasting are two new services that the European Space Agency (ESA) is investigating for future European and Global Mobile Satellite systems. ESA is active in promoting these services in their various mission options including non-geostationary and geostationary satellite systems. A Medium Altitude Global Satellite System (MAGSS) for global personal communications at L and S-band, and a Multiregional Highly inclined Elliptical Orbit (M-HEO) system for multiregional digital audio broadcasting at L-band are described. Both systems are being investigated by ESA in the context of future programs, such as Archimedes, which are intended to demonstrate the new services and to develop the technology for future non-geostationary mobile communication and broadcasting satellites.

Design of Remote Monitoring System of Irrigation based on GSM and ZigBee Technology

NASA Astrophysics Data System (ADS)

Xiao xi, Zheng; Fang, Zhao; Shuaifei, Shao

2018-03-01

To solve the problems of low level of irrigation and waste of water resources, a remote monitoring system for farmland irrigation based on GSM communication technology and ZigBee technology was designed. The system is composed of sensors, GSM communication module, ZigBee module, host computer, valve and so on. The system detects and closes the pump and the electromagnetic valve according to the need of the system, and transmits the monitoring information to the host computer or the user’s Mobile phone through the GSM communication network. Experiments show that the system has low power consumption, friendly man-machine interface, convenient and simple. It can monitor agricultural environment remotely and control related irrigation equipment at any time and place, and can better meet the needs of remote monitoring of farmland irrigation.

Automated alignment system for optical wireless communication systems using image recognition.

PubMed

Brandl, Paul; Weiss, Alexander; Zimmermann, Horst

2014-07-01

In this Letter, we describe the realization of a tracked line-of-sight optical wireless communication system for indoor data distribution. We built a laser-based transmitter with adaptive focus and ray steering by a microelectromechanical systems mirror. To execute the alignment procedure, we used a CMOS image sensor at the transmitter side and developed an algorithm for image recognition to localize the receiver's position. The receiver is based on a self-developed optoelectronic integrated chip with low requirements on the receiver optics to make the system economically attractive. With this system, we were able to set up the communication link automatically without any back channel and to perform error-free (bit error rate <10⁻⁹) data transmission over a distance of 3.5 m with a data rate of 3 Gbit/s.

Simultaneous classical communication and quantum key distribution using continuous variables

DOE Office of Scientific and Technical Information (OSTI.GOV)

Qi, Bing

Currently, classical optical communication systems employing strong laser pulses and quantum key distribution (QKD) systems working at single-photon levels are very different communication modalities. Dedicated devices are commonly required to implement QKD. In this paper, we propose a scheme which allows classical communication and QKD to be implemented simultaneously using the same communication infrastructure. More specially, we propose a coherent communication scheme where both the bits for classical communication and the Gaussian distributed random numbers for QKD are encoded on the same weak coherent pulse and decoded by the same coherent receiver. Simulation results based on practical system parameters showmore » that both deterministic classical communication with a bit error rate of 10 –9 and secure key distribution could be achieved over tens of kilometers of single-mode fibers. It is conceivable that in the future coherent optical communication network, QKD will be operated in the background of classical communication at a minimal cost.« less

Simultaneous classical communication and quantum key distribution using continuous variables

DOE PAGES

Qi, Bing

2016-10-26

Currently, classical optical communication systems employing strong laser pulses and quantum key distribution (QKD) systems working at single-photon levels are very different communication modalities. Dedicated devices are commonly required to implement QKD. In this paper, we propose a scheme which allows classical communication and QKD to be implemented simultaneously using the same communication infrastructure. More specially, we propose a coherent communication scheme where both the bits for classical communication and the Gaussian distributed random numbers for QKD are encoded on the same weak coherent pulse and decoded by the same coherent receiver. Simulation results based on practical system parameters showmore » that both deterministic classical communication with a bit error rate of 10 –9 and secure key distribution could be achieved over tens of kilometers of single-mode fibers. It is conceivable that in the future coherent optical communication network, QKD will be operated in the background of classical communication at a minimal cost.« less

MessageSpace: a messaging system for health research

NASA Astrophysics Data System (ADS)

Escobar, Rodrigo D.; Akopian, David; Parra-Medina, Deborah; Esparza, Laura

2013-03-01

Mobile Health (mHealth) has emerged as a promising direction for delivery of healthcare services via mobile communication devices such as cell phones. Examples include texting-based interventions for chronic disease monitoring, diabetes management, control of hypertension, smoking cessation, monitoring medication adherence, appointment keeping and medical test result delivery; as well as improving patient-provider communication, health information communication, data collection and access to health records. While existing messaging systems very well support bulk messaging and some polling applications, they are not designed for data collection and processing of health research oriented studies. For that reason known studies based on text-messaging campaigns have been constrained in participant numbers. In order to empower healthcare promotion and education research, this paper presents a system dedicated for healthcare research. It is designed for convenient communication with various study groups, feedback collection and automated processing.

Intuitive Tools for the Design and Analysis of Communication Payloads for Satellites

NASA Technical Reports Server (NTRS)

Culver, Michael R.; Soong, Christine; Warner, Joseph D.

2014-01-01

In an effort to make future communications satellite payload design more efficient and accessible, two tools were created with intuitive graphical user interfaces (GUIs). The first tool allows payload designers to graphically design their payload by using simple drag and drop of payload components onto a design area within the program. Information about each picked component is pulled from a database of common space-qualified communication components sold by commerical companies. Once a design is completed, various reports can be generated, such as the Master Equipment List. The second tool is a link budget calculator designed specifically for ease of use. Other features of this tool include being able to access a database of NASA ground based apertures for near Earth and Deep Space communication, the Tracking and Data Relay Satellite System (TDRSS) base apertures, and information about the solar system relevant to link budget calculations. The link budget tool allows for over 50 different combinations of user inputs, eliminating the need for multiple spreadsheets and the user errors associated with using them. Both of the aforementioned tools increase the productivity of space communication systems designers, and have the colloquial latitude to allow non-communication experts to design preliminary communication payloads.

PPM-based System for Guided Waves Communication Through Corrosion Resistant Multi-wire Cables

NASA Astrophysics Data System (ADS)

Trane, G.; Mijarez, R.; Guevara, R.; Pascacio, D.

Novel wireless communication channels are a necessity in applications surrounded by harsh environments, for instance down-hole oil reservoirs. Traditional radio frequency (RF) communication schemes are not capable of transmitting signals through metal enclosures surrounded by corrosive gases and liquids. As an alternative to RF, a pulse position modulation (PPM) guided waves communication system has been developed and evaluated using a corrosion resistant 4H18 multi-wire cable, commonly used to descend electronic gauges in down-hole oil applications, as the communication medium. The system consists of a transmitter and a receiver that utilizes a PZT crystal, for electrical/mechanical coupling, attached to each extreme of the multi-wire cable. The modulator is based on a microcontroller, which transmits60 kHz guided wave pulses, and the demodulator is based on a commercial digital signal processor (DSP) module that performs real time DSP algorithms. Experimental results are presented, which were obtained using a 1m corrosion resistant 4H18multi-wire cable, commonly used with downhole electronic gauges in the oil sector. Although there was significant dispersion and multiple mode excitations of the transmitted guided wave energy pulses, the results show that data rates on the order of 500 bits per second are readily available employing PPM and simple communications techniques.

A Methodical Development of Measures of Effectiveness for a Condition-Based Maintenance Management System

DTIC Science & Technology

2014-06-01

21 C . CMMS USE IN THE LCS PROGRAM ......................................................22 D. CBM+ MAINTENANCE MANAGEMENT SYSTEM...45 b. Plan Maintenance Budgeting .................................................45 c . Plan Maintenance Logistics... Maintenance Planning ...................................46 b. Communicate Maintenance Budget .......................................46 c . Communicate

49 CFR 661.11 - Rolling stock procurements.

Code of Federal Regulations, 2013 CFR

2013-10-01

... Devices; (21) Car Axle Counters; (22) Communication Based Train Control (CBTC). (u) Communication... components of a bus. This list is not all-inclusive. Car body shells, egines, transmissions, front axle... assemblies, air compressor and pneumatic systems, generator/alternator and electrical systems, steering...

49 CFR 661.11 - Rolling stock procurements.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Devices; (21) Car Axle Counters; (22) Communication Based Train Control (CBTC). (u) Communication... components of a bus. This list is not all-inclusive. Car body shells, egines, transmissions, front axle... assemblies, air compressor and pneumatic systems, generator/alternator and electrical systems, steering...

Two-way digital communications

NASA Astrophysics Data System (ADS)

Glenn, William E.; Daly, Ed

1996-03-01

The communications industry has been rapidly converting from analog to digital communications for audio, video, and data. The initial applications have been concentrating on point-to-multipoint transmission. Currently, a new revolution is occurring in which two-way point-to-point transmission is a rapidly growing market. The system designs for video compression developed for point-to-multipoint transmission are unsuitable for this new market as well as for satellite based video encoding. A new system developed by the Space Communications Technology Center has been designed to address both of these newer applications. An update on the system performance and design will be given.

A CSP-Based Agent Modeling Framework for the Cougaar Agent-Based Architecture

NASA Technical Reports Server (NTRS)

Gracanin, Denis; Singh, H. Lally; Eltoweissy, Mohamed; Hinchey, Michael G.; Bohner, Shawn A.

2005-01-01

Cognitive Agent Architecture (Cougaar) is a Java-based architecture for large-scale distributed agent-based applications. A Cougaar agent is an autonomous software entity with behaviors that represent a real-world entity (e.g., a business process). A Cougaar-based Model Driven Architecture approach, currently under development, uses a description of system's functionality (requirements) to automatically implement the system in Cougaar. The Communicating Sequential Processes (CSP) formalism is used for the formal validation of the generated system. Two main agent components, a blackboard and a plugin, are modeled as CSP processes. A set of channels represents communications between the blackboard and individual plugins. The blackboard is represented as a CSP process that communicates with every agent in the collection. The developed CSP-based Cougaar modeling framework provides a starting point for a more complete formal verification of the automatically generated Cougaar code. Currently it is used to verify the behavior of an individual agent in terms of CSP properties and to analyze the corresponding Cougaar society.

Orbital Angular Momentum Multiplexing over Visible Light Communication Systems

NASA Astrophysics Data System (ADS)

Tripathi, Hardik Rameshchandra

This thesis proposes and explores the possibility of using Orbital Angular Momentum multiplexing in Visible Light Communication system. Orbital Angular Momentum is mainly applied for laser and optical fiber transmissions, while Visible Light Communication is a technology using the light as a carrier for wireless communication. In this research, the study of the state of art and experiments showing some results on multiplexing based on Orbital Angular Momentum over Visible Light Communication system were done. After completion of the initial stage; research work and simulations were performed on spatial multiplexing over Li-Fi channel modeling. Simulation scenarios which allowed to evaluate the Signal-to-Noise Ratio, Received Power Distribution, Intensity and Illuminance were defined and developed.

Communication Technologies Preferred by School Based Administrators

ERIC Educational Resources Information Center

Weir, Paul

2012-01-01

The purpose of this study was to determine the communication technologies preferred by school based administrators. This study surveyed and interviewed 96 school based administrators in a mid-sized suburban school system. The data show that individual emails, email lists, and cell phone technologies had the highest percentage effectiveness ratings…

Experimental investigation of analog and digital dimming techniques on photometric performance of an indoor Visible Light Communication (VLC) system

NASA Astrophysics Data System (ADS)

Zafar, Fahad; Kalavally, Vineetha; Bakaul, Masuduzzaman; Parthiban, R.

2015-09-01

For making commercial implementation of light emitting diode (LED) based visible light communication (VLC) systems feasible, it is necessary to incorporate it with dimming schemes which will provide energy savings, moods and increase the aesthetic value of the places using this technology. There are two general methods which are used to dim LEDs commonly categorized as analog and digital dimming. Incorporating fast data transmission with these techniques is a key challenge in VLC. In this paper, digital and analog dimming for a 10 Mb/s non return to zero on-off keying (NRZ-OOK) based VLC system is experimentally investigated considering both photometric and communicative parameters. A spectrophotometer was used for photometric analysis and a line of sight (LOS) configuration in the presence of ambient light was used for analyzing communication parameters. Based on the experimental results, it was determined that digital dimming scheme is preferable for use in indoor VLC systems requiring high dimming precision and data transmission at lower brightness levels. On the other hand, analog dimming scheme is a cost effective solution for high speed systems where dimming precision is insignificant.

Global services systems - Space communication

NASA Technical Reports Server (NTRS)

Shepphird, F. H.; Wolbers, H. L.

1979-01-01

The requirements projected to the year 2000 for space-based global service systems, including both personal communications and innovative services, are developed based on historic trends and anticipated worldwide demographic and economic growth patterns. The growing demands appear to be best satisfied by developing larger, more sophisticated space systems in order to reduce the size, complexity, and expense of ground terminals. The availability of low-cost ground terminals will, in turn, further stimulate the generation of new services and new customers.

Integration, acceptance testing, and clinical operation of the Medical Information, Communication and Archive System, phase II.

PubMed

Smith, E M; Wandtke, J; Robinson, A

1999-05-01

The Medical Information, Communication and Archive System (MICAS) is a multivendor incremental approach to picture archiving and communications system (PACS). It is a multimodality integrated image management system that is seamlessly integrated with the radiology information system (RIS). Phase II enhancements of MICAS include a permanent archive, automated workflow, study caches, Microsoft (Redmond, WA) Windows NT diagnostic workstations with all components adhering to Digital Information Communications in Medicine (DICOM) standards. MICAS is designed as an enterprise-wide PACS to provide images and reports throughout the Strong Health healthcare network. Phase II includes the addition of a Cemax-Icon (Fremont, CA) archive, PACS broker (Mitra, Waterloo, Canada), an interface (IDX PACSlink, Burlington, VT) to the RIS (IDXrad) plus the conversion of the UNIX-based redundant array of inexpensive disks (RAID) 5 temporary archives in phase I to NT-based RAID 0 DICOM modality-specific study caches (ImageLabs, Bedford, MA). The phase I acquisition engines and workflow management software was uninstalled and the Cemax archive manager (AM) assumed these functions. The existing ImageLabs UNIX-based viewing software was enhanced and converted to an NT-based DICOM viewer. Installation of phase II hardware and software and integration with existing components began in July 1998. Phase II of MICAS demonstrates that a multivendor open-system incremental approach to PACS is feasible, cost-effective, and has significant advantages over a single-vendor implementation.

A GPS-based Real-time Road Traffic Monitoring System

NASA Astrophysics Data System (ADS)

Tanti, Kamal Kumar

In recent years, monitoring systems are astonishingly inclined towards ever more automatic; reliably interconnected, distributed and autonomous operation. Specifically, the measurement, logging, data processing and interpretation activities may be carried out by separate units at different locations in near real-time. The recent evolution of mobile communication devices and communication technologies has fostered a growing interest in the GIS & GPS-based location-aware systems and services. This paper describes a real-time road traffic monitoring system based on integrated mobile field devices (GPS/GSM/IOs) working in tandem with advanced GIS-based application software providing on-the-fly authentications for real-time monitoring and security enhancement. The described system is developed as a fully automated, continuous, real-time monitoring system that employs GPS sensors and Ethernet and/or serial port communication techniques are used to transfer data between GPS receivers at target points and a central processing computer. The data can be processed locally or remotely based on the requirements of client’s satisfaction. Due to the modular architecture of the system, other sensor types may be supported with minimal effort. Data on the distributed network & measurements are transmitted via cellular SIM cards to a Control Unit, which provides for post-processing and network management. The Control Unit may be remotely accessed via an Internet connection. The new system will not only provide more consistent data about the road traffic conditions but also will provide methods for integrating with other Intelligent Transportation Systems (ITS). For communication between the mobile device and central monitoring service GSM technology is used. The resulting system is characterized by autonomy, reliability and a high degree of automation.

Achievable Strength-Based Signal Detection in Quantity-Constrained PAM OOK Concentration-Encoded Molecular Communication.

PubMed

Mahfuz, Mohammad Upal

2016-10-01

In this paper, the expressions of achievable strength-based detection probabilities of concentration-encoded molecular communication (CEMC) system have been derived based on finite pulsewidth (FP) pulse-amplitude modulated (PAM) on-off keying (OOK) modulation scheme and strength threshold. An FP-PAM system is characterized by its duty cycle α that indicates the fraction of the entire symbol duration the transmitter remains on and transmits the signal. Results show that the detection performance of an FP-PAM OOK CEMC system significantly depends on the statistical distribution parameters of diffusion-based propagation noise and intersymbol interference (ISI). Analytical detection performance of an FP-PAM OOK CEMC system under ISI scenario has been explained and compared based on receiver operating characteristics (ROC) for impulse (i.e., spike)-modulated (IM) and FP-PAM CEMC schemes. It is shown that the effects of diffusion noise and ISI on ROC can be explained separately based on their communication range-dependent statistics. With full duty cycle, an FP-PAM scheme provides significantly worse performance than an IM scheme. The paper also analyzes the performance of the system when duty cycle, transmission data rate, and quantity of molecules vary.

Star Tracker Based ATP System Conceptual Design and Pointing Accuracy Estimation

NASA Technical Reports Server (NTRS)

Orfiz, Gerardo G.; Lee, Shinhak

2006-01-01

A star tracker based beaconless (a.k.a. non-cooperative beacon) acquisition, tracking and pointing concept for precisely pointing an optical communication beam is presented as an innovative approach to extend the range of high bandwidth (> 100 Mbps) deep space optical communication links throughout the solar system and to remove the need for a ground based high power laser as a beacon source. The basic approach for executing the ATP functions involves the use of stars as the reference sources from which the attitude knowledge is obtained and combined with high bandwidth gyroscopes for propagating the pointing knowledge to the beam pointing mechanism. Details of the conceptual design are presented including selection of an orthogonal telescope configuration and the introduction of an optical metering scheme to reduce misalignment error. Also, estimates are presented that demonstrate that aiming of the communications beam to the Earth based receive terminal can be achieved with a total system pointing accuracy of better than 850 nanoradians (3 sigma) from anywhere in the solar system.

Understanding the Psycho-Physiological Implications of Interaction With a Virtual Reality-Based System in Adolescents With Autism: A Feasibility Study.

PubMed

Kuriakose, Selvia; Lahiri, Uttama

2015-07-01

Individuals with Autism are characterized by deficits in socialization and communication. In recent years several assistive technologies, e.g., Virtual Reality (VR), have been investigated to address the socialization deficits in these individuals. Presently available VR-based systems address various aspects of social communication in an isolated manner and without monitoring one's affective state such as, anxiety. However, in conventional observation-based therapy, a therapist adjusts the intervention paradigm by monitoring one's anxiety level. But, often these individuals have an inherent inability to explicitly express their anxiety thereby inducing limitations on conventional techniques. Physiological signals being continuously available and not directly impacted by these communication difficulties can be alternatively used as markers of one's anxiety level. In our research we aim at designing a Virtual-reality bAsed Social-communication Task (VAST) system that can address the various aspects of social communication, e.g., social context, subtle social cues, emotional expression, etc., in a cumulative and structured way. In addition, we augment this with a capability to use one's physiological signals as markers of one's anxiety level. In our preliminary feasibility study we investigate the potential of VAST to cause variations in one's performance and anxiety level that can be mapped from one's physiological indices.

Spread Spectrum Based Energy Efficient Collaborative Communication in Wireless Sensor Networks.

PubMed

Ghani, Anwar; Naqvi, Husnain; Sher, Muhammad; Khan, Muazzam Ali; Khan, Imran; Irshad, Azeem

2016-01-01

Wireless sensor networks consist of resource limited devices. Most crucial of these resources is battery life, as in most applications like battle field or volcanic area monitoring, it is often impossible to replace or recharge the power source. This article presents an energy efficient collaborative communication system based on spread spectrum to achieve energy efficiency as well as immunity against jamming, natural interference, noise suppression and universal frequency reuse. Performance of the proposed system is evaluated using the received signal power, bit error rate (BER) and energy consumption. The results show a direct proportionality between the power gain and the number of collaborative nodes as well as BER and signal-to-noise ratio (Eb/N0). The analytical and simulation results of the proposed system are compared with SISO system. The comparison reveals that SISO perform better than collaborative communication in case of small distances whereas collaborative communication performs better than SISO in case of long distances. On the basis of these results it is safe to conclude that collaborative communication in wireless sensor networks using wideband systems improves the life time of nodes in the networks thereby prolonging the network's life time.

Trellis coding with Continuous Phase Modulation (CPM) for satellite-based land-mobile communications

NASA Technical Reports Server (NTRS)

1989-01-01

This volume of the final report summarizes the results of our studies on the satellite-based mobile communications project. It includes: a detailed analysis, design, and simulations of trellis coded, full/partial response CPM signals with/without interleaving over various Rician fading channels; analysis and simulation of computational cutoff rates for coherent, noncoherent, and differential detection of CPM signals; optimization of the complete transmission system; analysis and simulation of power spectrum of the CPM signals; design and development of a class of Doppler frequency shift estimators; design and development of a symbol timing recovery circuit; and breadboard implementation of the transmission system. Studies prove the suitability of the CPM system for mobile communications.

Augmentative Communication Services in the Schools.

ERIC Educational Resources Information Center

Blackstone, Sarah W.

1989-01-01

The article considers current issues concerning service delivery systems and practices concerning augmentative and alternative communication (AAC) services in U.S. schools. Concerns in AAC program development are noted and service delivery models (center-based, community-based, or collaborative) are compared. (DB)

Microstrip monopulse antenna for land mobile communications

NASA Technical Reports Server (NTRS)

Garcia, Q.; Martin, C.; Delvalle, J. C.; Jongejans, A.; Rinous, P.; Travers, M. N.

1993-01-01

Low cost is one of the main requirements in a communication system suitable for mass production, as it is the case for satellite land mobile communications. Microstrip technology fulfills this requirement which must be supported by a low cost tracking system design. The tradeoff led us to a prototype antenna composed of microstrip patches based on electromechanical closed-loop principle; the design and the results obtained are described.

An Experimental Realization of a Chaos-Based Secure Communication Using Arduino Microcontrollers.

PubMed

Zapateiro De la Hoz, Mauricio; Acho, Leonardo; Vidal, Yolanda

2015-01-01

Security and secrecy are some of the important concerns in the communications world. In the last years, several encryption techniques have been proposed in order to improve the secrecy of the information transmitted. Chaos-based encryption techniques are being widely studied as part of the problem because of the highly unpredictable and random-look nature of the chaotic signals. In this paper we propose a digital-based communication system that uses the logistic map which is a mathematically simple model that is chaotic under certain conditions. The input message signal is modulated using a simple Delta modulator and encrypted using a logistic map. The key signal is also encrypted using the same logistic map with different initial conditions. In the receiver side, the binary-coded message is decrypted using the encrypted key signal that is sent through one of the communication channels. The proposed scheme is experimentally tested using Arduino shields which are simple yet powerful development kits that allows for the implementation of the communication system for testing purposes.

Controller–Pilot Data Link Communication Security

PubMed Central

Polishchuk, Tatiana; Wernberg, Max

2018-01-01

The increased utilization of the new types of cockpit communications, including controller–pilot data link communications (CPDLC), puts the airplane at higher risk of hacking or interference than ever before. We review the technological characteristics and properties of the CPDLC and construct the corresponding threat model. Based on the limitations imposed by the system parameters, we propose several solutions for the improved security of the data messaging communication used in air traffic management (ATM). We discuss the applicability of elliptical curve cryptography (ECC), protected aircraft communications addressing and reporting systems (PACARs) and the Host Identity Protocol (HIP) as possible countermeasures to the identified security threats. In addition, we consider identity-defined networking (IDN) as an example of a genuine security solution which implies global changes in the whole air traffic communication system. PMID:29783791

Controller⁻Pilot Data Link Communication Security.

PubMed

Gurtov, Andrei; Polishchuk, Tatiana; Wernberg, Max

2018-05-20

The increased utilization of the new types of cockpit communications, including controller⁻pilot data link communications (CPDLC), puts the airplane at higher risk of hacking or interference than ever before. We review the technological characteristics and properties of the CPDLC and construct the corresponding threat model. Based on the limitations imposed by the system parameters, we propose several solutions for the improved security of the data messaging communication used in air traffic management (ATM). We discuss the applicability of elliptical curve cryptography (ECC), protected aircraft communications addressing and reporting systems (PACARs) and the Host Identity Protocol (HIP) as possible countermeasures to the identified security threats. In addition, we consider identity-defined networking (IDN) as an example of a genuine security solution which implies global changes in the whole air traffic communication system.

Differential phase-shift keying and channel equalization in free space optical communication system

NASA Astrophysics Data System (ADS)

Zhang, Dai; Hao, Shiqi; Zhao, Qingsong; Wan, Xiongfeng; Xu, Chenlu

2018-01-01

We present the performance benefits of differential phase-shift keying (DPSK) modulation in eliminating influence from atmospheric turbulence, especially for coherent free space optical (FSO) communication with a high communication rate. Analytic expression of detected signal is derived, based on which, homodyne detection efficiency is calculated to indicate the performance of wavefront compensation. Considered laser pulses always suffer from atmospheric scattering effect by clouds, intersymbol interference (ISI) in high-speed FSO communication link is analyzed. Correspondingly, the channel equalization method of a binormalized modified constant modulus algorithm based on set-membership filtering (SM-BNMCMA) is proposed to solve the ISI problem. Finally, through the comparison with existing channel equalization methods, its performance benefits of both ISI elimination and convergence speed are verified. The research findings have theoretical significance in a high-speed FSO communication system.

Ubiquitous Connected Train Based on Train-to-Ground and Intra-Wagon Communications Capable of Providing on Trip Customized Digital Services for Passengers

PubMed Central

Salaberria, Itziar; Perallos, Asier; Azpilicueta, Leire; Falcone, Francisco; Carballedo, Roberto; Angulo, Ignacio; Elejoste, Pilar; Bahillo, Alfonso; Astrain, José Javier; Villadangos, Jesús

2014-01-01

During the last years, the application of different wireless technologies has been explored in order to enable Internet connectivity from vehicles. In addition, the widespread adoption of smartphones by citizens represents a great opportunity to integrate such nomadic devices inside vehicles in order to provide new and personalized on trip services for passengers. In this paper, a proposal of communication architecture to provide the ubiquitous connectivity needed to enhance the smart train concept is presented and preliminarily tested. It combines an intra-wagon communication system based on nomadic devices connected through a Bluetooth Piconet Network with a highly innovative train-to-ground communication system. In order to validate this communication solution, several tests and simulations have been performed and their results are described in this paper. PMID:24803192

Airborne Visible Laser Optical Communications Program (AVLOC)

NASA Technical Reports Server (NTRS)

Ward, J. H.

1975-01-01

The design, development, and operation of airborne and ground-based laser communications and laser radar hardware is described in support of the Airborne Visible Laser Optical Communication program. The major emphasis is placed on the development of a highly flexible test bed for the evaluation of laser communications systems techniques and components in an operational environment.

Teaching Communication Skills to Radiology Residents.

PubMed

Itri, Jason N; Yacob, Sammy; Mithqal, Ayman

The transition of health care in the United States from volume to value requires a systems-based approach aligning clinical services across the continuum of care. The ability to communicate effectively and resolve conflict is a critical skill within the systems-based model. Recognizing the essential role of communication in medicine, the Accreditation Council of Graduate Medical Education has designated interpersonal and communication skills a core competency for all residents regardless of specialty. Yet, communication skills are often developed through on-the-job training or not at all. Traditional educational curricula use a predominantly didactic approach without opportunities for trainees to observe, actively experiment, or reflect on what is learned as a part of the learning process. In this article, we describe a 1-day experiential communication skills workshop customized for radiology residents that consists of Myers-Briggs Type Indicator and conflict management sessions designed to develop interpersonal, communication, and conflict management skills through group discussion, role-play, and simulation. The purpose of this educational initiative was to determine the perceived value of an experiential communication skills workshop designed for radiology trainees. Copyright © 2017 Elsevier Inc. All rights reserved.

Categories of Electronic Publications in a College Information System. AIR 1992 Annual Forum Paper.

ERIC Educational Resources Information Center

Taylor, Allan

This paper identifies and describes the categories of electronic publications (EPs) in a document-based communication and information system called JIMMY, developed by Queen Margaret College (Edinburgh, Scotland) for use by students and staff in general arts and paramedical courses. The use of computer-mediated communication systems like bulletin…

Intelligent fault isolation and diagnosis for communication satellite systems

NASA Technical Reports Server (NTRS)

Tallo, Donald P.; Durkin, John; Petrik, Edward J.

1992-01-01

Discussed here is a prototype diagnosis expert system to provide the Advanced Communication Technology Satellite (ACTS) System with autonomous diagnosis capability. The system, the Fault Isolation and Diagnosis EXpert (FIDEX) system, is a frame-based system that uses hierarchical structures to represent such items as the satellite's subsystems, components, sensors, and fault states. This overall frame architecture integrates the hierarchical structures into a lattice that provides a flexible representation scheme and facilitates system maintenance. FIDEX uses an inexact reasoning technique based on the incrementally acquired evidence approach developed by Shortliffe. The system is designed with a primitive learning ability through which it maintains a record of past diagnosis studies.

Wireless Communications in Smart Grid

NASA Astrophysics Data System (ADS)

Bojkovic, Zoran; Bakmaz, Bojan

Communication networks play a crucial role in smart grid, as the intelligence of this complex system is built based on information exchange across the power grid. Wireless communications and networking are among the most economical ways to build the essential part of the scalable communication infrastructure for smart grid. In particular, wireless networks will be deployed widely in the smart grid for automatic meter reading, remote system and customer site monitoring, as well as equipment fault diagnosing. With an increasing interest from both the academic and industrial communities, this chapter systematically investigates recent advances in wireless communication technology for the smart grid.

Evaluation of the impact of a CPOE system on nurse-physician communication--a mixed method study.

PubMed

Pirnejad, H; Niazkhani, Z; van der Sijs, H; Berg, M; Bal, R

2009-01-01

To assess the impact of a CPOE system on medication-related communication of nurses and physicians. In six internal medicine wards of an academic medical center, two questionnaires were used to evaluate nurses' attitudes toward the impact of a paper-based medication system and then a CPOE system on their communication in medication-related-activities (medication work). The questionnaires were analyzed using t-tests, followed by Bonferroni correction. Nine nurses and six physicians in the same wards were interviewed after the implementation to determine how their communication and their work have been impacted by the system. The total response rates were 54% and 52% for pre- and post-implementation questionnaires. It was shown that after implementation, the legibility and completeness of prescriptions were significantly improved (P <.001) and the administration system had a more intelligible layout (P <.001), with a more reliable overview (P <.001). The analysis of the interviews supported and confirmed the findings of the surveys. Moreover, they showed communication problems that caused difficulties in integrating medication work of nurses into physicians'. To compensate for these, nurses and physicians devised informal interactions and practices (workarounds), which often represented risks for medication errors. The introduction of CPOE system with paper-based medication administration system improved prescription legibility and completeness but introduced many workflow impediments and as a result error-inducing conditions. In order to prevent such an effect, CPOE systems have to support the level of communication which is necessary to integrate the work of nurses and physicians.

Leader-following control of multiple nonholonomic systems over directed communication graphs

NASA Astrophysics Data System (ADS)

Dong, Wenjie; Djapic, Vladimir

2016-06-01

This paper considers the leader-following control problem of multiple nonlinear systems with directed communication topology and a leader. If the state of each system is measurable, distributed state feedback controllers are proposed using neighbours' state information with the aid of Lyapunov techniques and properties of Laplacian matrix for time-invariant communication graph and time-varying communication graph. It is shown that the state of each system exponentially converges to the state of a leader. If the state of each system is not measurable, distributed observer-based output feedback control laws are proposed. As an application of the proposed results, formation control of wheeled mobile robots is studied. The simulation results show the effectiveness of the proposed results.

The Telecommunications and Data Acquisition Report

NASA Technical Reports Server (NTRS)

Yuen, Joseph H. (Editor)

1993-01-01

This quarterly publication provides archival reports on developments in programs managed by JPL's Office of Telecommunications and Data Acquisition (TDA). In space communications, radio navigation, radio science, and ground-based radio and radar astronomy, it reports on activities of the Deep Space Network (DSN) in planning, supporting research and technology, implementation, and operations. Also included are standards activity at JPL for space data and information systems and reimbursable DSN work performed for other space agencies through NASA. The papers included in this document cover satellite tracking and ground-based navigation, spacecraft-ground communications, and optical communication systems for the Deep Space Network.

Modeling of Adaptive Optics-Based Free-Space Communications Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wilks, S C; Morris, J R; Brase, J M

2002-08-06

We introduce a wave-optics based simulation code written for air-optic laser communications links, that includes a detailed model of an adaptive optics compensation system. We present the results obtained by this model, where the phase of a communications laser beam is corrected, after it propagates through a turbulent atmosphere. The phase of the received laser beam is measured using a Shack-Hartmann wavefront sensor, and the correction method utilizes a MEMS mirror. Strehl improvement and amount of power coupled to the receiving fiber for both 1 km horizontal and 28 km slant paths are presented.

TMS communications software. Volume 2: Bus interface unit

NASA Technical Reports Server (NTRS)

Gregor, P. J.

1979-01-01

A data bus communication system to support the space shuttle's Trend Monitoring System (TMS) and to provide a basis for evaluation of the bus concept is described. Installation of the system included developing both hardware and software interfaces between the bus and the specific TMS computers and terminals. The software written for the microprocessor-based bus interface units is described. The software implements both the general bus communications protocol and also the specific interface protocols for the TMS computers and terminals.

Deep convolutional neural network based antenna selection in multiple-input multiple-output system

NASA Astrophysics Data System (ADS)

Cai, Jiaxin; Li, Yan; Hu, Ying

2018-03-01

Antenna selection of wireless communication system has attracted increasing attention due to the challenge of keeping a balance between communication performance and computational complexity in large-scale Multiple-Input MultipleOutput antenna systems. Recently, deep learning based methods have achieved promising performance for large-scale data processing and analysis in many application fields. This paper is the first attempt to introduce the deep learning technique into the field of Multiple-Input Multiple-Output antenna selection in wireless communications. First, the label of attenuation coefficients channel matrix is generated by minimizing the key performance indicator of training antenna systems. Then, a deep convolutional neural network that explicitly exploits the massive latent cues of attenuation coefficients is learned on the training antenna systems. Finally, we use the adopted deep convolutional neural network to classify the channel matrix labels of test antennas and select the optimal antenna subset. Simulation experimental results demonstrate that our method can achieve better performance than the state-of-the-art baselines for data-driven based wireless antenna selection.

IpexT: Integrated Planning and Execution for Military Satellite Tele-Communications

NASA Technical Reports Server (NTRS)

Plaunt, Christian; Rajan, Kanna

2004-01-01

The next generation of military communications satellites may be designed as a fast packet-switched constellation of spacecraft able to withstand substantial bandwidth capacity fluctuation in the face of dynamic resource utilization and rapid environmental changes including jamming of communication frequencies and unstable weather phenomena. We are in the process of designing an integrated scheduling and execution tool which will aid in the analysis of the design parameters needed for building such a distributed system for nominal and battlefield communications. This paper discusses the design of such a system based on a temporal constraint posting planner/scheduler and a smart executive which can cope with a dynamic environment to make a more optimal utilization of bandwidth than the current circuit switched based approach.

Alternative Theoretical Bases for the Study of Human Communication: The Systems Perspective.

ERIC Educational Resources Information Center

Monge, Peter R.

Three potentially useful perspectives for the scientific development of human communication theory are the law model, the systems approach, and the rules paradigm. It is the purpose of this paper to indicate the utility of the systems approach. The first section of this paper provides a brief account of the systems view of the world. Outlined in…

SDR/STRS Flight Experiment and the Role of SDR-Based Communication and Navigation Systems

NASA Technical Reports Server (NTRS)

Reinhart, Richard C.

2008-01-01

This presentation describes an open architecture SDR (software defined radio) infrastructure, suitable for space-based radios and operations, entitled Space Telecommunications Radio System (STRS). SDR technologies will endow space and planetary exploration systems with dramatically increased capability, reduced power consumption, and less mass than conventional systems, at costs reduced by vigorous competition, hardware commonality, dense integration, minimizing the impact of parts obsolescence, improved interoperability, and software re-use. To advance the SDR architecture technology and demonstrate its applicability in space, NASA is developing a space experiment of multiple SDRs each with various waveforms to communicate with NASA s TDRSS satellite and ground networks, and the GPS constellation. An experiments program will investigate S-band and Ka-band communications, navigation, and networking technologies and operations.

High-fidelity video and still-image communication based on spectral information: natural vision system and its applications

NASA Astrophysics Data System (ADS)

Yamaguchi, Masahiro; Haneishi, Hideaki; Fukuda, Hiroyuki; Kishimoto, Junko; Kanazawa, Hiroshi; Tsuchida, Masaru; Iwama, Ryo; Ohyama, Nagaaki

2006-01-01

In addition to the great advancement of high-resolution and large-screen imaging technology, the issue of color is now receiving considerable attention as another aspect than the image resolution. It is difficult to reproduce the original color of subject in conventional imaging systems, and that obstructs the applications of visual communication systems in telemedicine, electronic commerce, and digital museum. To breakthrough the limitation of conventional RGB 3-primary systems, "Natural Vision" project aims at an innovative video and still-image communication technology with high-fidelity color reproduction capability, based on spectral information. This paper summarizes the results of NV project including the development of multispectral and multiprimary imaging technologies and the experimental investigations on the applications to medicine, digital archives, electronic commerce, and computer graphics.

Distributed On-line Monitoring System Based on Modem and Public Phone Net

NASA Astrophysics Data System (ADS)

Chen, Dandan; Zhang, Qiushi; Li, Guiru

In order to solve the monitoring problem of urban sewage disposal, a distributed on-line monitoring system is proposed. By introducing dial-up communication technology based on Modem, the serial communication program can rationally solve the information transmission problem between master station and slave station. The realization of serial communication program is based on the MSComm control of C++ Builder 6.0.The software includes real-time data operation part and history data handling part, which using Microsoft SQL Server 2000 for database, and C++ Builder6.0 for user interface. The monitoring center displays a user interface with alarm information of over-standard data and real-time curve. Practical application shows that the system has successfully accomplished the real-time data acquisition from data gather station, and stored them in the terminal database.

Characterizing Nanoscale Transient Communication.

PubMed

Chen, Yifan; Anwar, Putri Santi; Huang, Limin; Asvial, Muhamad

2016-04-01

We consider the novel paradigm of nanoscale transient communication (NTC), where certain components of the small-scale communication link are physically transient. As such, the transmitter and the receiver may change their properties over a prescribed lifespan due to their time-varying structures. The NTC systems may find important applications in the biomedical, environmental, and military fields, where system degradability allows for benign integration into life and environment. In this paper, we analyze the NTC systems from the channel-modeling and capacity-analysis perspectives and focus on the stochastically meaningful slow transience scenario, where the coherence time of degeneration Td is much longer than the coding delay Tc. We first develop novel and parsimonious models to characterize the NTC channels, where three types of physical layers are considered: electromagnetism-based terahertz (THz) communication, diffusion-based molecular communication (DMC), and nanobots-assisted touchable communication (TouchCom). We then revisit the classical performance measure of ϵ-outage channel capacity and take a fresh look at its formulations in the NTC context. Next, we present the notion of capacity degeneration profile (CDP), which describes the reduction of channel capacity with respect to the degeneration time. Finally, we provide numerical examples to demonstrate the features of CDP. To the best of our knowledge, the current work represents a first attempt to systematically evaluate the quality of nanoscale communication systems deteriorating with time.

C-Band Airport Surface Communications System Standards Development, Phase I

NASA Technical Reports Server (NTRS)

Hall, Edward; Isaacs, James; Zelkin, Natalie; Henriksen. Steve

2010-01-01

This document is being provided as part of ITT's NASA Glenn Research Center Aerospace Communication Systems Technical Support (ACSTS) contract NNC05CA85C, Task 7: "New ATM Requirements--Future Communications, C-Band and L-Band Communications Standard Development." The proposed future C-band (5091- to 5150-MHz) airport surface communication system, referred to as the Aeronautical Mobile Airport Communications System (AeroMACS), is anticipated to increase overall air-to-ground data communications systems capacity by using a new spectrum (i.e., not very high frequency (VHF)). Although some critical services could be supported, AeroMACS will also target noncritical services, such as weather advisory and aeronautical information services as part of an airborne System Wide Information Management (SWIM) program. AeroMACS is to be designed and implemented in a manner that will not disrupt other services operating in the C-band. This report defines the AeroMACS concepts of use, high-level system requirements, and architecture; the performance of supporting system analyses; the development of AeroMACS test and demonstration plans; and the establishment of an operational AeroMACS capability in support of C-band aeronautical data communications standards to be advanced in both international (International Civil Aviation Organization, ICAO) and national (RTCA) forums. This includes the development of system parameter profile recommendations for AeroMACS based on existing Institute of Electrical and Electronics Engineering (IEEE) 802.16e- 2009 standards

47 CFR 74.431 - Special rules applicable to remote pickup stations.

Code of Federal Regulations, 2010 CFR

2010-10-01

... system. (b) Remote pickup mobile or base stations may be used for communications related to production... pickup mobile or base stations may communicate with any other station licensed under this subpart. (d... additional frequency is limited to 2.5 watts. (f) Remote pickup base and mobile stations in Alaska, Guam...

Information Issues and Contexts that Impair Team Based Communication Workflow: A Palliative Sedation Case Study.

PubMed

Cornett, Alex; Kuziemsky, Craig

2015-01-01

Implementing team based workflows can be complex because of the scope of providers involved and the extent of information exchange and communication that needs to occur. While a workflow may represent the ideal structure of communication that needs to occur, information issues and contextual factors may impact how the workflow is implemented in practice. Understanding these issues will help us better design systems to support team based workflows. In this paper we use a case study of palliative sedation therapy (PST) to model a PST workflow and then use it to identify purposes of communication, information issues and contextual factors that impact them. We then suggest how our findings could inform health information technology (HIT) design to support team based communication workflows.

Modeling the Atmospheric Phase Effects of a Digital Antenna Array Communications System

NASA Technical Reports Server (NTRS)

Tkacenko, A.

2006-01-01

In an antenna array system such as that used in the Deep Space Network (DSN) for satellite communication, it is often necessary to account for the effects due to the atmosphere. Typically, the atmosphere induces amplitude and phase fluctuations on the transmitted downlink signal that invalidate the assumed stationarity of the signal model. The degree to which these perturbations affect the stationarity of the model depends both on parameters of the atmosphere, including wind speed and turbulence strength, and on parameters of the communication system, such as the sampling rate used. In this article, we focus on modeling the atmospheric phase fluctuations in a digital antenna array communications system. Based on a continuous-time statistical model for the atmospheric phase effects, we show how to obtain a related discrete-time model based on sampling the continuous-time process. The effects of the nonstationarity of the resulting signal model are investigated using the sample matrix inversion (SMI) algorithm for minimum mean-squared error (MMSE) equalization of the received signal

Crowdsourcing-Assisted Radio Environment Database for V2V Communication.

PubMed

Katagiri, Keita; Sato, Koya; Fujii, Takeo

2018-04-12

In order to realize reliable Vehicle-to-Vehicle (V2V) communication systems for autonomous driving, the recognition of radio propagation becomes an important technology. However, in the current wireless distributed network systems, it is difficult to accurately estimate the radio propagation characteristics because of the locality of the radio propagation caused by surrounding buildings and geographical features. In this paper, we propose a measurement-based radio environment database for improving the accuracy of the radio environment estimation in the V2V communication systems. The database first gathers measurement datasets of the received signal strength indicator (RSSI) related to the transmission/reception locations from V2V systems. By using the datasets, the average received power maps linked with transmitter and receiver locations are generated. We have performed measurement campaigns of V2V communications in the real environment to observe RSSI for the database construction. Our results show that the proposed method has higher accuracy of the radio propagation estimation than the conventional path loss model-based estimation.

Performance Comparison with Different Antenna Properties in Time Reversal Ultra-Wideband Communications for Sensor System Applications

PubMed Central

Ding, Shuai

2017-01-01

The complexity reduction of receivers in ultrawideband (UWB) communication when time reversal (TR) technique is applied makes it suitable for low-cost and low-power sensor systems. Larger antenna dispersion can generally lead to a less stable phase center and will increase the interference in UWB communications based on pulse radio, whereas a higher antenna gain will result in higher channel gain and further larger channel capacity. To find out the trade-off between antenna gain and dispersion, we performed the channel measurements using different antennas in a dense multipath environment and established the distribution of channel capacities based on the measured channel responses. The results show that the capacity loss caused by antenna dispersion cannot be compensated by antenna gain with line-of-sight transmission to some extent, the effect of phase center on the communication system is negligible, and antennas with smaller time dispersion will have a better energy focusing property and anti-interference performance in TR systems. PMID:29301195

Performance Comparison with Different Antenna Properties in Time Reversal Ultra-Wideband Communications for Sensor System Applications.

PubMed

Yang, Yu; Wang, Bing-Zhong; Ding, Shuai

2017-12-30

The complexity reduction of receivers in ultrawideband (UWB) communication when time reversal (TR) technique is applied makes it suitable for low-cost and low-power sensor systems. Larger antenna dispersion can generally lead to a less stable phase center and will increase the interference in UWB communications based on pulse radio, whereas a higher antenna gain will result in higher channel gain and further larger channel capacity. To find out the trade-off between antenna gain and dispersion, we performed the channel measurements using different antennas in a dense multipath environment and established the distribution of channel capacities based on the measured channel responses. The results show that the capacity loss caused by antenna dispersion cannot be compensated by antenna gain with line-of-sight transmission to some extent, the effect of phase center on the communication system is negligible, and antennas with smaller time dispersion will have a better energy focusing property and anti-interference performance in TR systems.

Nurse practitioner-based sign-out system to facilitate patient communication on a neurosurgical service: a pilot study with recommendations.

PubMed

Rabinovitch, Deborah L; Hamill, Melinda; Zanchetta, Clauda; Bernstein, Mark

2009-12-01

Failure to communicate important patient information between physicians causes medical errors and adverse patient events. On-call neurosurgery physicians at the Toronto Western Hospital do not know the medical details of all the patients that they are covering at night because they do not care for the entire service of patients during the day. Because there is no formal handover system to transfer patient information to the on-call physician, a nurse practitioner-based sign-out system was recently introduced. Its effectiveness for communication was evaluated with preintervention-postintervention questionnaires and by recording daily logins. There was a statistically significant decrease in number of logins after 8 weeks of use (p = .05, Fisher's exact test), and the tool was abandoned after 16 weeks. Modifications identified to improve the system include the ability to sort by attending physician and to automatically populate the list with new patients. Effective communication is important for reducing medical errors, and perhaps these modifications will facilitate this important endeavor.

Crowdsourcing-Assisted Radio Environment Database for V2V Communication †

PubMed Central

Katagiri, Keita; Fujii, Takeo

2018-01-01

In order to realize reliable Vehicle-to-Vehicle (V2V) communication systems for autonomous driving, the recognition of radio propagation becomes an important technology. However, in the current wireless distributed network systems, it is difficult to accurately estimate the radio propagation characteristics because of the locality of the radio propagation caused by surrounding buildings and geographical features. In this paper, we propose a measurement-based radio environment database for improving the accuracy of the radio environment estimation in the V2V communication systems. The database first gathers measurement datasets of the received signal strength indicator (RSSI) related to the transmission/reception locations from V2V systems. By using the datasets, the average received power maps linked with transmitter and receiver locations are generated. We have performed measurement campaigns of V2V communications in the real environment to observe RSSI for the database construction. Our results show that the proposed method has higher accuracy of the radio propagation estimation than the conventional path loss model-based estimation. PMID:29649174

An ontology-based telemedicine tasks management system architecture.

PubMed

Nageba, Ebrahim; Fayn, Jocelyne; Rubel, Paul

2008-01-01

The recent developments in ambient intelligence and ubiquitous computing offer new opportunities for the design of advanced Telemedicine systems providing high quality services, anywhere, anytime. In this paper we present an approach for building an ontology-based task-driven telemedicine system. The architecture is composed of a task management server, a communication server and a knowledge base for enabling decision makings taking account of different telemedical concepts such as actors, resources, services and the Electronic Health Record. The final objective is to provide an intelligent management of the different types of available human, material and communication resources.

Compact optical duplicate system for satellite-ground laser communications: application of averaging effects

NASA Astrophysics Data System (ADS)

Nakayama, Tomoko; Takayama, Yoshihisa; Fujikawa, Chiemi; Watanabe, Eriko; Kodate, Kashiko

2014-09-01

In recent years, there has been considerable interest in satellite-ground laser communication due to an increase in the quantity of data exchanged between satellites and the ground. However, improving the quality of this data communication is necessary as laser communication is vulnerable to air fluctuation. We first verify the spatial and temporal averaging effects using light beam intensity images acquired from middle-range transmission experiments between two ground positions and the superposition of these images using simulations. Based on these results, we propose a compact and lightweight optical duplicate system as a multi-beam generation device with which it is easy to apply the spatial averaging effect. Although an optical duplicate system is already used for optical correlation operations, we present optimum design solutions, design a compact optical duplicate system for satellite-ground laser communications, and demonstrate the efficacy of this system using simulations.

Whither Space Power? Forging a Strategy for the New Century

DTIC Science & Technology

2002-09-01

cyber dimension. The physical assets that comprise communications networks— Courtesy of NASA Advanced Communication Technology Satellite 90...location to the energy produc­ tion and use site. As long-distance energy transmission be- comes feasible, this physical transport will undoubtedly mi­ grate...to space-based transmission systems much as communications systems have done and are continuing to do. 96 WORDEN Once this happens, we will have

Earth Conductivity Estimation from Through-the-Earth Measurements of 94 Coal Mines Using Different Electromagnetic Models

PubMed Central

Yan, Lincan; Waynert, Joseph; Sunderman, Carl

2015-01-01

Through-the-Earth (TTE) communication systems require minimal infrastructure to operate. Hence, they are assumed to be more survivable and more conventional than other underground mine communications systems. This survivability is a major advantage for TTE systems. In 2006, Congress passed the Mine Improvement and New Emergency Response Act (MINER Act), which requires all underground coal mines to install wireless communications systems. The intent behind this mandate is for trapped miners to be able to communicate with surface personnel after a major accident-hence, the interest in TTE communications. To determine the likelihood of establishing a TTE communication link, it would be ideal to be able to predict the apparent conductivity of the overburden above underground mines. In this paper, all 94 mine TTE measurement data collected by Bureau of Mines in the 1970s and early 1980s, are analyzed for the first time to determine the apparent conductivity of the overburden based on three different models: a homogenous half-space model, a thin sheet model, and an attenuation factor or Q-factor model. A statistical formula is proposed to estimate the apparent earth conductivity for a specific mine based on the TTE modeling results given the mine depth and signal frequency. PMID:26213457

Earth Conductivity Estimation from Through-the-Earth Measurements of 94 Coal Mines Using Different Electromagnetic Models.

PubMed

Yan, Lincan; Waynert, Joseph; Sunderman, Carl

2014-10-01

Through-the-Earth (TTE) communication systems require minimal infrastructure to operate. Hence, they are assumed to be more survivable and more conventional than other underground mine communications systems. This survivability is a major advantage for TTE systems. In 2006, Congress passed the Mine Improvement and New Emergency Response Act (MINER Act), which requires all underground coal mines to install wireless communications systems. The intent behind this mandate is for trapped miners to be able to communicate with surface personnel after a major accident-hence, the interest in TTE communications. To determine the likelihood of establishing a TTE communication link, it would be ideal to be able to predict the apparent conductivity of the overburden above underground mines. In this paper, all 94 mine TTE measurement data collected by Bureau of Mines in the 1970s and early 1980s, are analyzed for the first time to determine the apparent conductivity of the overburden based on three different models: a homogenous half-space model, a thin sheet model, and an attenuation factor or Q-factor model. A statistical formula is proposed to estimate the apparent earth conductivity for a specific mine based on the TTE modeling results given the mine depth and signal frequency.

Services, architectures, and protocols for space data systems

NASA Technical Reports Server (NTRS)

Helgert, Hermann J.

1991-01-01

The author presents a comprehensive discussion of three major aspects of the work of the Consultative Committee for Space Data Systems (CCSDS), a worldwide cooperative effort of national space agencies. The author examines the CCSDS space data communications network concept on which the data communications facilities of future advanced orbiting systems will be based. He derives the specifications of an open communications architecture as a reference model for the development of services and protocols that support the transfer of information over space data communications networks. Detailed specifications of the communication services and information transfer protocols that have reached a high degree of maturity and stability are offered. The author also includes a complete list of currently available CCSDS standards and supporting documentation.

Data Collection for Mobile Group Consumption: An Asynchronous Distributed Approach.

PubMed

Zhu, Weiping; Chen, Weiran; Hu, Zhejie; Li, Zuoyou; Liang, Yue; Chen, Jiaojiao

2016-04-06

Mobile group consumption refers to consumption by a group of people, such as a couple, a family, colleagues and friends, based on mobile communications. It differs from consumption only involving individuals, because of the complex relations among group members. Existing data collection systems for mobile group consumption are centralized, which has the disadvantages of being a performance bottleneck, having single-point failure and increasing business and security risks. Moreover, these data collection systems are based on a synchronized clock, which is often unrealistic because of hardware constraints, privacy concerns or synchronization cost. In this paper, we propose the first asynchronous distributed approach to collecting data generated by mobile group consumption. We formally built a system model thereof based on asynchronous distributed communication. We then designed a simulation system for the model for which we propose a three-layer solution framework. After that, we describe how to detect the causality relation of two/three gathering events that happened in the system based on the collected data. Various definitions of causality relations based on asynchronous distributed communication are supported. Extensive simulation results show that the proposed approach is effective for data collection relating to mobile group consumption.

Data Collection for Mobile Group Consumption: An Asynchronous Distributed Approach †

PubMed Central

Zhu, Weiping; Chen, Weiran; Hu, Zhejie; Li, Zuoyou; Liang, Yue; Chen, Jiaojiao

2016-01-01

Mobile group consumption refers to consumption by a group of people, such as a couple, a family, colleagues and friends, based on mobile communications. It differs from consumption only involving individuals, because of the complex relations among group members. Existing data collection systems for mobile group consumption are centralized, which has the disadvantages of being a performance bottleneck, having single-point failure and increasing business and security risks. Moreover, these data collection systems are based on a synchronized clock, which is often unrealistic because of hardware constraints, privacy concerns or synchronization cost. In this paper, we propose the first asynchronous distributed approach to collecting data generated by mobile group consumption. We formally built a system model thereof based on asynchronous distributed communication. We then designed a simulation system for the model for which we propose a three-layer solution framework. After that, we describe how to detect the causality relation of two/three gathering events that happened in the system based on the collected data. Various definitions of causality relations based on asynchronous distributed communication are supported. Extensive simulation results show that the proposed approach is effective for data collection relating to mobile group consumption. PMID:27058544

Mold heating and cooling microprocessor conversion. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hoffman, D.P.

Conversion of the microprocessors and software for the Mold Heating and Cooling (MHAC) pump package control systems was initiated to allow required system enhancements and provide data communications capabilities with the Plastics Information and Control System (PICS). The existing microprocessor-based control systems for the pump packages use an Intel 8088-based microprocessor board with a maximum of 64 Kbytes of program memory. The requirements for the system conversion were developed, and hardware has been selected to allow maximum reuse of existing hardware and software while providing the required additional capabilities and capacity. The new hardware will incorporate an Intel 80286-based microprocessormore » board with an 80287 math coprocessor, the system includes additional memory, I/O, and RS232 communication ports.« less

An internet-based communication network for information transfer during patient transitions from skilled nursing facility to the emergency department.

PubMed

Hustey, Fredric M; Palmer, Robert M

2010-06-01

To determine whether the implementation of an Internet-based communication system improves the amount of essential information conveyed between a skilled nursing facility (SNF) and the emergency department (ED) during patient care transitions. Interventional; before and after. ED of an urban teaching hospital with approximately 55,000 visits per year and a 55-bed subacute free-standing rehabilitation facility (the SNF). All patients transferred from the SNF to the ED over 16 months. An Internet-based communication network with SNF-ED transfer form for communication during patient care transitions. Nine elements of patient information assessed before and after intervention through chart review. changes in efficiency of information transfer and staff satisfaction. Two hundred thirty-four of 237 preintervention and all 276 postintervention care transitions were reviewed. The Internet communication network was used in 78 (26%) of all care transitions, peaking at 40% by the end of the study. There was more critical patient information (1.85 vs 4.29 of 9 elements; P<.001) contained within fewer pages of transfer documents (24.47 vs 5.15; P<.001) after the intervention. Staff satisfaction with communication was higher among ED physicians after the intervention. The use of an Internet-based system increased the amount of information communicated during SNF-ED care transitions and significantly reduced the number of pages in which this information was contained.

Proceedings of the Fifth International Mobile Satellite Conference 1997

NASA Technical Reports Server (NTRS)

Jedrey, T. (Compiler); Rigley, J. (Compiler); Anderson, Louise (Editor)

1997-01-01

Satellite-based mobile communications systems provide voice and data communications to users over a vast geographic area. The users may communicate via mobile or hand-held terminals, which may also provide access to terrestrial communications services. While previous International Mobile Satellite Conferences have concentrated on technical advances and the increasing worldwide commercial activities, this conference focuses on the next generation of mobile satellite services. The approximately 80 papers included here cover sessions in the following areas: networking and protocols; code division multiple access technologies; demand, economics and technology issues; current and planned systems; propagation; terminal technology; modulation and coding advances; spacecraft technology; advanced systems; and applications and experiments.

Digital modulation and achievable information rates of thru-body haptic communications

NASA Astrophysics Data System (ADS)

Hanisch, Natalie; Pierobon, Massimiliano

2017-05-01

The ever increasing biocompatibility and pervasive nature of wearable and implantable devices demand novel sustainable solutions to realize their connectivity, which can impact broad application scenarios such as in the defense, biomedicine, and entertainment fields. Where wireless electromagnetic communications are facing challenges such as device miniaturization, energy scarcity, limited range, and possibility of interception, solutions not only inspired but also based on natural communication means might result into valid alternatives. In this paper, a communication paradigm where digital information is propagated through the nervous system is proposed and analyzed on the basis of achievable information rates. In particular, this paradigm is based on an analytical framework where the response of a system based on haptic (tactile) information transmission and ElectroEncephaloGraphy (EEG)-based reception is modeled and characterized. Computational neuroscience models of the somatosensory signal representation in the brain, coupled with models of the generation and propagation of somatosensory stimulation from skin mechanoreceptors, are employed in this paper to provide a proof-of-concept evaluation of achievable performance in encoding information bits into tactile stimulation, and decoding them from the recorded brain activity. Based on these models, the system is simulated and the resulting data are utilized to train a Support Vector Machine (SVM) classifier, which is finally used to provide a proof-of-concept validation of the system performance in terms of information rates against bit error probability at the reception.

Utilizing the ISS Mission as a Testbed to Develop Cognitive Communications Systems

NASA Technical Reports Server (NTRS)

Jackson, Dan

2016-01-01

The ISS provides an excellent opportunity for pioneering artificial intelligence software to meet the challenges of real-time communications (comm) link management. This opportunity empowers the ISS Program to forge a testbed for developing cognitive communications systems for the benefit of the ISS mission, manned Low Earth Orbit (LEO) science programs and future planetary exploration programs. In November, 1998, the Flight Operations Directorate (FOD) started the ISS Antenna Manager (IAM) project to develop a single processor supporting multiple comm satellite tracking for two different antenna systems. Further, the processor was developed to be highly adaptable as it supported the ISS mission through all assembly stages. The ISS mission mandated communications specialists with complete knowledge of when the ISS was about to lose or gain comm link service. The current specialty mandated cognizance of large sun-tracking solar arrays and thermal management panels in addition to the highly-dynamic satellite service schedules and rise/set tables. This mission requirement makes the ISS the ideal communications management analogue for future LEO space station and long-duration planetary exploration missions. Future missions, with their precision-pointed, dynamic, laser-based comm links, require complete autonomy for managing high-data rate communications systems. Development of cognitive communications management systems that permit any crew member or payload science specialist, regardless of experience level, to control communications is one of the greater benefits the ISS can offer new space exploration programs. The IAM project met a new mission requirement never previously levied against US space-born communications systems management: process and display the orientation of large solar arrays and thermal control panels based on real-time joint angle telemetry. However, IAM leaves the actual communications availability assessment to human judgment, which introduces unwanted variability because each specialist has a different core of experience with comm link performance. Because the ISS utilizes two different frequency bands, dynamic structure can be occasionally translucent at one frequency while it can completely interdict service at the other frequency. The impact of articulating structure on the comm link can depend on its orientation at the time it impinges on the link. It can become easy for a human specialist to cross-associate experience at one frequency with experience at the other frequency. Additionally, the specialist's experience is incremental, occurring one nine-hour shift at a time. Only the IAM processor experiences the complete 24x7x365 communications link performance for both communications links but, it has no "learning capability." If the IAM processor could be endowed with a cognitive ability to remember past structure-induced comm link outages, based on its knowledge of the ISS position, attitude, communications gear, array joint angles and tracking accuracy, it could convey such experience to the human operator. It could also use its learned communications link behaviors to accurately convey the availability of future communications sessions. Further, the tool could remember how accurately or inaccurately it predicted availability and correct future predictions based on past performance. The IAM tool could learn frequency-specific impacts due to spacecraft structures and pass that information along as "experience." Such development would provide a single artificial intelligence processor that could provide two different experience bases. If it also "knew" the satellite service schedule, it could distinguish structure blockage from schedule or planet blockage and then quickly switch to another satellite. Alternatively, just as a human operator could judge, a cognizant comm system based on the IAM model could "know" that the blockage is not going to last very long and continue tracking a comm satellite, waiting for it to track away from structure. Ultimately, once this capability was fully developed and tested in the Mission Control Center, it could be transferred on-orbit to support development of operations concepts that include more advanced cognitive communications systems. Future applications of this capability are easily foreseen because even more dynamic satellite constellations with more nodes and greater capability are coming. Currently, the ISS fully employs a 300 million bit-per-second (Mbps) return link for harvesting payload science. In the coming eighteen months, it will step up to 600 Mbps. Already there is talk of a 1.2 billion bit-per-second (Gbps) upgrade for the ISS and laser comm links have already been tested from the ISS. Every data rate upgrade mandates more complicated and sensitive communications equipment which implies greater expertise invested in the human operator. Future on-orbit cognizant comm systems will be needed to meet greater performance demands aboard larger, far more complicated spacecraft. In the LEO environment, the old-style one-satellite-per-spacecraft operations concept will give way to a new concept of a single customer spacecraft simultaneously using multiple comm satellites. Much more highly-dynamic manned LEO missions with decades of crew members potentially increase the demand for communications link performance. A cognizant on-board communications system will meet advanced communications demands from future LEO missions and future planetary missions. The ISS has fledgling components of future exploration programs, both LEO and planetary. Further, the Flight Operations Directorate, through the IAM project, has already begun to develop a communications management system that attempts to solve advanced problems ideally represented by dynamic structure impacting scheduled satellite service. With an earnest project to integrate artificial intelligence into the IAM processor, the ISS Program could develop a cognizant communications system that could be adapted and transferred to future on-orbit avionics designs.

Utilizing the ISS Mission as a Testbed to Develop Cognitive Communications Systems

NASA Technical Reports Server (NTRS)

Jackson, Dan

2016-01-01

The ISS provides an excellent opportunity for pioneering artificial intelligence software to meet the challenges of real-time communications (comm) link management. This opportunity empowers the ISS Program to forge a testbed for developing cognitive communications systems for the benefit of the ISS mission, manned Low Earth Orbit (LEO) science programs and future planetary exploration programs. In November, 1998, the Flight Operations Directorate (FOD) started the ISS Antenna Manager (IAM) project to develop a single processor supporting multiple comm satellite tracking for two different antenna systems. Further, the processor was developed to be highly adaptable as it supported the ISS mission through all assembly stages. The ISS mission mandated communications specialists with complete knowledge of when the ISS was about to lose or gain comm link service. The current specialty mandated cognizance of large sun-tracking solar arrays and thermal management panels in addition to the highly-dynamic satellite service schedules and rise/set tables. This mission requirement makes the ISS the ideal communications management analogue for future LEO space station and long-duration planetary exploration missions. Future missions, with their precision-pointed, dynamic, laser-based comm links, require complete autonomy for managing high-data rate communications systems. Development of cognitive communications management systems that permit any crew member or payload science specialist, regardless of experience level, to control communications is one of the greater benefits the ISS can offer new space exploration programs. The IAM project met a new mission requirement never previously levied against US space-born communications systems management: process and display the orientation of large solar arrays and thermal control panels based on real-time joint angle telemetry. However, IAM leaves the actual communications availability assessment to human judgement, which introduces unwanted variability because each specialist has a different core of experience with comm link performance. Because the ISS utilizes two different frequency bands, dynamic structure can be occasionally translucent at one frequency while it can completely interdict service at the other frequency. The impact of articulating structure on the comm link can depend on its orientation at the time it impinges on the link. It can become easy for a human specialist to cross-associate experience at one frequency with experience at the other frequency. Additionally, the specialist's experience is incremental, occurring one nine-hour shift at a time. Only the IAM processor experiences the complete 24x7x365 communications link performance for both communications links but, it has no "learning capability." If the IAM processor could be endowed with a cognitive ability to remember past structure-induced comm link outages, based on its knowledge of the ISS position, attitude, communications gear, array joint angles and tracking accuracy, it could convey such experience to the human operator. It could also use its learned communications link behaviors to accurately convey the availability of future communications sessions. Further, the tool could remember how accurately or inaccurately it predicted availability and correct future predictions based on past performance. The IAM tool could learn frequency-specific impacts due to spacecraft structures and pass that information along as "experience." Such development would provide a single artificial intelligence processor that could provide two different experience bases. If it also "knew" the satellite service schedule, it could distinguish structure blockage from schedule or planet blockage and then quickly switch to another satellite. Alternatively, just as a human operator could judge, a cognizant comm system based on the IAM model could "know" that the blockage is not going to last very long and continue tracking a comm satellite, waiting for it to track away from structure. Ultimately, once this capability was fully developed and tested in the Mission Control Center, it could be transferred on-orbit to support development of operations concepts that include more advanced cognitive communications systems. Future applications of this capability are easily foreseen because even more dynamic satellite constellations with more nodes and greater capability are coming. Currently, the ISS fully employs its high-data-rate return link for harvesting payload science. In the coming months, it will double that data rate and is forecast to fully utilize that capability. Already there is talk of an upgrade that quadruples the current data rate allocated to ISS payload science before the end of its mission and laser comm links have already been tested from the ISS. Every data rate upgrade mandates more complicated and sensitive communications equipment which implies greater expertise invested in the human operator. Future on-orbit cognizant comm systems will be needed to meet greater performance demands aboard larger, far more complicated spacecraft. In the LEO environment, the old-style one-satellite-per-spacecraft operations concept will give way to a new concept of a single customer spacecraft simultaneously using multiple comm satellites. Much more highly-dynamic manned LEO missions with decades of crew members potentially increase the demand for communications link performance. A cognizant on-board communications system will meet advanced communications demands from future LEO missions and future planetary missions. The ISS has fledgling components of future exploration programs, both LEO and planetary. Further, the Flight Operations Directorate, through the IAM project, has already begun to develop a communications management system that attempts to solve advanced problems ideally represented by dynamic structure impacting scheduled satellite service. With an earnest project to integrate artificial intelligence into the IAM processor, the ISS Program could develop a cognizant communications system that could be adapted and transferred to future on-orbit avionics designs.

Transmission monitoring and control of strategic communication systems

NASA Astrophysics Data System (ADS)

Farrow, J. E.; Skerjanec, R. E.

1986-03-01

This paper discusses a minicomputer-based communication system monitor used by the U.S. Department of Defense to improve the service availability and reduce the operating costs of the new multichannel digital transmission systems. A brief history of the development of the monitor and a general description of the present-generation hardware and software are included.

The Telecommunications and Data Acquisition Report

NASA Technical Reports Server (NTRS)

Posner, E. C. (Editor)

1984-01-01

Activities in space communication, radio navigation, radio science, and ground-based astronomy are reported. Advanced systems for the Deep Space Network and its Ground-Communications Facility are discussed including station control and system technology. Network sustaining as well as data and information systems are covered. Studies of geodynamics, investigations of the microwave spectrum, and the search for extraterrestrial intelligence are reported.

In-Space Internet-Based Communications for Space Science Platforms Using Commercial Satellite Networks

NASA Technical Reports Server (NTRS)

Kerczewski, Robert J.; Bhasin, Kul B.; Fabian, Theodore P.; Griner, James H.; Kachmar, Brian A.; Richard, Alan M.

1999-01-01

The continuing technological advances in satellite communications and global networking have resulted in commercial systems that now can potentially provide capabilities for communications with space-based science platforms. This reduces the need for expensive government owned communications infrastructures to support space science missions while simultaneously making available better service to the end users. An interactive, high data rate Internet type connection through commercial space communications networks would enable authorized researchers anywhere to control space-based experiments in near real time and obtain experimental results immediately. A space based communications network architecture consisting of satellite constellations connecting orbiting space science platforms to ground users can be developed to provide this service. The unresolved technical issues presented by this scenario are the subject of research at NASA's Glenn Research Center in Cleveland, Ohio. Assessment of network architectures, identification of required new or improved technologies, and investigation of data communications protocols are being performed through testbed and satellite experiments and laboratory simulations.

Scheduled Peripheral Component Interconnect Arbiter

NASA Technical Reports Server (NTRS)

Nixon, Scott Alan (Inventor)

2015-01-01

Systems and methods are described for arbitrating access of a communication bus. In one embodiment, a method includes performing steps on one or more processors. The steps include: receiving an access request from a device of the communication bus; evaluating a bus schedule to determine an importance of the device based on the access request; and selectively granting access of the communication bus to the device based on the importance of the device.

Near Field Communication and Health: Turning a Mobile Phone into an Interactive Multipurpose Assistant in Healthcare Scenarios

NASA Astrophysics Data System (ADS)

Benelli, Giuliano; Pozzebon, Alessandro

In this paper we discuss the introduction of the Near Field Communication (NFC) technology in the management of the assistance operations in the hospitals. NFC is a new short range communication system based on RFID technology.

Mobile-Based Dictionary of Information and Communication Technology

NASA Astrophysics Data System (ADS)

Liando, O. E. S.; Mewengkang, A.; Kaseger, D.; Sangkop, F. I.; Rantung, V. P.; Rorimpandey, G. C.

2018-02-01

This study aims to design and build mobile-based dictionary of information and communication technology applications to provide access to information in the form of glossary of terms in the context of information and communication technologies. Applications built in this study using the Android platform, with SQLite database model. This research uses prototype model development method which covers the stages of communication, Quick Plan, Quick Design Modeling, Construction of Prototype, Deployment Delivery & Feedback, and Full System Transformation. The design of this application is designed in such a way as to facilitate the user in the process of learning and understanding the new terms or vocabularies encountered in the world of information and communication technology. Mobile-based dictionary of Information And Communication Technology applications that have been built can be an alternative to learning literature. In its simplest form, this application is able to meet the need for a comprehensive and accurate dictionary of Information And Communication Technology function.

Secure steganographic communication algorithm based on self-organizing patterns.

PubMed

Saunoriene, Loreta; Ragulskis, Minvydas

2011-11-01

A secure steganographic communication algorithm based on patterns evolving in a Beddington-de Angelis-type predator-prey model with self- and cross-diffusion is proposed in this paper. Small perturbations of initial states of the system around the state of equilibrium result in the evolution of self-organizing patterns. Small differences between initial perturbations result in slight differences also in the evolving patterns. It is shown that the generation of interpretable target patterns cannot be considered as a secure mean of communication because contours of the secret image can be retrieved from the cover image using statistical techniques if only it represents small perturbations of the initial states of the system. An alternative approach when the cover image represents the self-organizing pattern that has evolved from initial states perturbed using the dot-skeleton representation of the secret image can be considered as a safe visual communication technique protecting both the secret image and communicating parties.

EEG-Based Brain–Computer Interfaces for Communication and Rehabilitation of People with Motor Impairment: A Novel Approach of the 21st Century

PubMed Central

Lazarou, Ioulietta; Nikolopoulos, Spiros; Petrantonakis, Panagiotis C.; Kompatsiaris, Ioannis; Tsolaki, Magda

2018-01-01

People with severe neurological impairments face many challenges in sensorimotor functions and communication with the environment; therefore they have increased demand for advanced, adaptive and personalized rehabilitation. During the last several decades, numerous studies have developed brain–computer interfaces (BCIs) with the goals ranging from providing means of communication to functional rehabilitation. Here we review the research on non-invasive, electroencephalography (EEG)-based BCI systems for communication and rehabilitation. We focus on the approaches intended to help severely paralyzed and locked-in patients regain communication using three different BCI modalities: slow cortical potentials, sensorimotor rhythms and P300 potentials, as operational mechanisms. We also review BCI systems for restoration of motor function in patients with spinal cord injury and chronic stroke. We discuss the advantages and limitations of these approaches and the challenges that need to be addressed in the future. PMID:29472849

Improving the Effectiveness of Electronic Health Record-Based Referral Processes

PubMed Central

2012-01-01

Electronic health records are increasingly being used to facilitate referral communication in the outpatient setting. However, despite support by technology, referral communication between primary care providers and specialists is often unsatisfactory and is unable to eliminate care delays. This may be in part due to lack of attention to how information and communication technology fits within the social environment of health care. Making electronic referral communication effective requires a multifaceted “socio-technical” approach. Using an 8-dimensional socio-technical model for health information technology as a framework, we describe ten recommendations that represent good clinical practices to design, develop, implement, improve, and monitor electronic referral communication in the outpatient setting. These recommendations were developed on the basis of our previous work, current literature, sound clinical practice, and a systems-based approach to understanding and implementing health information technology solutions. Recommendations are relevant to system designers, practicing clinicians, and other stakeholders considering use of electronic health records to support referral communication. PMID:22973874

Quick acquisition and recognition method for the beacon in deep space optical communications.

PubMed

Wang, Qiang; Liu, Yuefei; Ma, Jing; Tan, Liying; Yu, Siyuan; Li, Changjiang

2016-12-01

In deep space optical communications, it is very difficult to acquire the beacon given the long communication distance. Acquisition efficiency is essential for establishing and holding the optical communication link. Here we proposed a quick acquisition and recognition method for the beacon in deep optical communications based on the characteristics of the deep optical link. To identify the beacon from the background light efficiently, we utilized the maximum similarity between the collecting image and the reference image for accurate recognition and acquisition of the beacon in the area of uncertainty. First, the collecting image and the reference image were processed by Fourier-Mellin. Second, image sampling and image matching were applied for the accurate positioning of the beacon. Finally, the field programmable gate array (FPGA)-based system was used to verify and realize this method. The experimental results showed that the acquisition time for the beacon was as fast as 8.1s. Future application of this method in the system design of deep optical communication will be beneficial.

STBC AF relay for unmanned aircraft system

NASA Astrophysics Data System (ADS)

Adachi, Fumiyuki; Miyazaki, Hiroyuki; Endo, Chikara

2015-01-01

If a large scale disaster similar to the Great East Japan Earthquake 2011 happens, some areas may be isolated from the communications network. Recently, unmanned aircraft system (UAS) based wireless relay communication has been attracting much attention since it is able to quickly re-establish the connection between isolated areas and the network. However, the channel between ground station (GS) and unmanned aircraft (UA) is unreliable due to UA's swing motion and as consequence, the relay communication quality degrades. In this paper, we introduce space-time block coded (STBC) amplify-and-forward (AF) relay for UAS based wireless relay communication to improve relay communication quality. A group of UAs forms single frequency network (SFN) to perform STBC-AF cooperative relay. In STBC-AF relay, only conjugate operation, block exchange and amplifying are required at UAs. Therefore, STBC-AF relay improves the relay communication quality while alleviating the complexity problem at UAs. It is shown by computer simulation that STBC-AF relay can achieve better throughput performance than conventional AF relay.

Mutual-Information-Based Incremental Relaying Communications for Wireless Biomedical Implant Systems

PubMed Central

Liao, Yangzhe; Cai, Qing; Ai, Qingsong; Liu, Quan

2018-01-01

Network lifetime maximization of wireless biomedical implant systems is one of the major research challenges of wireless body area networks (WBANs). In this paper, a mutual information (MI)-based incremental relaying communication protocol is presented where several on-body relay nodes and one coordinator are attached to the clothes of a patient. Firstly, a comprehensive analysis of a system model is investigated in terms of channel path loss, energy consumption, and the outage probability from the network perspective. Secondly, only when the MI value becomes smaller than the predetermined threshold is data transmission allowed. The communication path selection can be either from the implanted sensor to the on-body relay then forwards to the coordinator or from the implanted sensor to the coordinator directly, depending on the communication distance. Moreover, mathematical models of quality of service (QoS) metrics are derived along with the related subjective functions. The results show that the MI-based incremental relaying technique achieves better performance in comparison to our previous proposed protocol techniques regarding several selected performance metrics. The outcome of this paper can be applied to intra-body continuous physiological signal monitoring, artificial biofeedback-oriented WBANs, and telemedicine system design. PMID:29419784

Mutual-Information-Based Incremental Relaying Communications for Wireless Biomedical Implant Systems.

PubMed

Liao, Yangzhe; Leeson, Mark S; Cai, Qing; Ai, Qingsong; Liu, Quan

2018-02-08

Network lifetime maximization of wireless biomedical implant systems is one of the major research challenges of wireless body area networks (WBANs). In this paper, a mutual information (MI)-based incremental relaying communication protocol is presented where several on-body relay nodes and one coordinator are attached to the clothes of a patient. Firstly, a comprehensive analysis of a system model is investigated in terms of channel path loss, energy consumption, and the outage probability from the network perspective. Secondly, only when the MI value becomes smaller than the predetermined threshold is data transmission allowed. The communication path selection can be either from the implanted sensor to the on-body relay then forwards to the coordinator or from the implanted sensor to the coordinator directly, depending on the communication distance. Moreover, mathematical models of quality of service (QoS) metrics are derived along with the related subjective functions. The results show that the MI-based incremental relaying technique achieves better performance in comparison to our previous proposed protocol techniques regarding several selected performance metrics. The outcome of this paper can be applied to intra-body continuous physiological signal monitoring, artificial biofeedback-oriented WBANs, and telemedicine system design.

Satellite Communications for Aeronautical Applications: Recent research and Development Results

NASA Technical Reports Server (NTRS)

Kerczewski, Robert J.

2001-01-01

Communications systems have always been a critical element in aviation. Until recently, nearly all communications between the ground and aircraft have been based on analog voice technology. But the future of global aviation requires a more sophisticated "information infrastructure" which not only provides more and better communications, but integrates the key information functions (communications, navigation, and surveillance) into a modern, network-based infrastructure. Satellite communications will play an increasing role in providing information infrastructure solutions for aviation. Developing and adapting satellite communications technologies for aviation use is now receiving increased attention as the urgency to develop information infrastructure solutions grows. The NASA Glenn Research Center is actively involved in research and development activities for aeronautical satellite communications, with a key emphasis on air traffic management communications needs. This paper describes the recent results and status of NASA Glenn's research program.

Group consensus control for networked multi-agent systems with communication delays.

PubMed

An, Bao-Ran; Liu, Guo-Ping; Tan, Chong

2018-05-01

This paper investigates group consensus problems in networked multi-agent systems (NMAS) with communication delays. Based on the sed state prediction scheme, the group consensus control protocol is designed to compensate the communication delay actively. In light of algebraic graph theories and matrix theories, necessary and(or) sufficient conditions of group consensus with respect to a given admissible control set are obtained for the NMAS with communication delays under mild assumptions. Finally, simulations are performed to demonstrate the effectiveness of the theoretical results. Copyright © 2018 ISA. All rights reserved.

Pilot-aided feedforward data recovery in optical coherent communications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Qi, Bing

2017-09-19

A method and a system for pilot-aided feedforward data recovery are provided. The method and system include a receiver including a strong local oscillator operating in a free running mode independent of a signal light source. The phase relation between the signal light source and the local oscillator source is determined based on quadrature measurements on pilot pulses from the signal light source. Using the above phase relation, information encoded in an incoming signal can be recovered, optionally for use in communication with classical coherent communication protocols and quantum communication protocols.

Comparative evaluation of the content and structure of communication using two handoff tools: implications for patient safety.

PubMed

Abraham, Joanna; Kannampallil, Thomas G; Almoosa, Khalid F; Patel, Bela; Patel, Vimla L

2014-04-01

Handoffs vary in their structure and content, raising concerns regarding standardization. We conducted a comparative evaluation of the nature and patterns of communication on 2 functionally similar but conceptually different handoff tools: Subjective, Objective, Assessment and Plan, based on a patient problem-based format, and Handoff Intervention Tool (HAND-IT), based on a body system-based format. A nonrandomized pre-post prospective intervention study supported by audio recordings and observations of 82 resident handoffs was conducted in a medical intensive care unit. Qualitative analysis was complemented with exploratory sequential pattern analysis techniques to capture the characteristics and types of communication events (CEs) and breakdowns. Use of HAND-IT led to fewer communication breakdowns (F1,80 = 45.66: P < .0001), greater number of CEs (t40 = 4.56; P < .001), with more ideal CEs than Subjective, Objective, Assessment and Plan (t40 = 9.27; P < .001). In addition, the use of HAND-IT was characterized by more request-response CE transitions. The HAND-IT's body system-based structure afforded physicians the ability to better organize and comprehend patient information and led to an interactive and streamlined communication, with limited external input. Our results also emphasize the importance of information organization using a medical knowledge hierarchical format for fostering effective communication. Copyright © 2014 Elsevier Inc. All rights reserved.

Taking the Politics Out of Satellite and Space-Based Communications Protocols

NASA Technical Reports Server (NTRS)

Ivancic, William D.

2006-01-01

After many years of studies, experimentation, and deployment, large amounts of misinformation and misconceptions remain regarding applicability of various communications protocols for use in satellite and space-based networks. This paper attempts to remove much of the politics, misconceptions, and misinformation that have plagued spacebased communications protocol development and deployment. This paper provides a common vocabulary for communications; a general discussion of the requirements for various communication environments; an evaluation of tradeoffs between circuit and packet-switching technologies, and the pros and cons of various link, network, transport, application, and security protocols. Included is the applicability of protocol enhancing proxies to NASA, Department of Defense (DOD), and commercial space communication systems.

Research on Formation of Microsatellite Communication with Genetic Algorithm

PubMed Central

Wu, Guoqiang; Bai, Yuguang; Sun, Zhaowei

2013-01-01

For the formation of three microsatellites which fly in the same orbit and perform three-dimensional solid mapping for terra, this paper proposes an optimizing design method of space circular formation order based on improved generic algorithm and provides an intersatellite direct spread spectrum communication system. The calculating equation of LEO formation flying satellite intersatellite links is guided by the special requirements of formation-flying microsatellite intersatellite links, and the transmitter power is also confirmed throughout the simulation. The method of space circular formation order optimizing design based on improved generic algorithm is given, and it can keep formation order steady for a long time under various absorb impetus. The intersatellite direct spread spectrum communication system is also provided. It can be found that, when the distance is 1 km and the data rate is 1 Mbps, the input wave matches preferably with the output wave. And LDPC code can improve the communication performance. The correct capability of (512, 256) LDPC code is better than (2, 1, 7) convolution code, distinctively. The design system can satisfy the communication requirements of microsatellites. So, the presented method provides a significant theory foundation for formation-flying and intersatellite communication. PMID:24078796

Research on formation of microsatellite communication with genetic algorithm.

PubMed

Wu, Guoqiang; Bai, Yuguang; Sun, Zhaowei

2013-01-01

For the formation of three microsatellites which fly in the same orbit and perform three-dimensional solid mapping for terra, this paper proposes an optimizing design method of space circular formation order based on improved generic algorithm and provides an intersatellite direct spread spectrum communication system. The calculating equation of LEO formation flying satellite intersatellite links is guided by the special requirements of formation-flying microsatellite intersatellite links, and the transmitter power is also confirmed throughout the simulation. The method of space circular formation order optimizing design based on improved generic algorithm is given, and it can keep formation order steady for a long time under various absorb impetus. The intersatellite direct spread spectrum communication system is also provided. It can be found that, when the distance is 1 km and the data rate is 1 Mbps, the input wave matches preferably with the output wave. And LDPC code can improve the communication performance. The correct capability of (512, 256) LDPC code is better than (2, 1, 7) convolution code, distinctively. The design system can satisfy the communication requirements of microsatellites. So, the presented method provides a significant theory foundation for formation-flying and intersatellite communication.

Dynamic Reconfiguration of a RGBD Sensor Based on QoS and QoC Requirements in Distributed Systems.

PubMed

Munera, Eduardo; Poza-Lujan, Jose-Luis; Posadas-Yagüe, Juan-Luis; Simó-Ten, José-Enrique; Noguera, Juan Fco Blanes

2015-07-24

The inclusion of embedded sensors into a networked system provides useful information for many applications. A Distributed Control System (DCS) is one of the clearest examples where processing and communications are constrained by the client's requirements and the capacity of the system. An embedded sensor with advanced processing and communications capabilities supplies high level information, abstracting from the data acquisition process and objects recognition mechanisms. The implementation of an embedded sensor/actuator as a Smart Resource permits clients to access sensor information through distributed network services. Smart resources can offer sensor services as well as computing, communications and peripheral access by implementing a self-aware based adaptation mechanism which adapts the execution profile to the context. On the other hand, information integrity must be ensured when computing processes are dynamically adapted. Therefore, the processing must be adapted to perform tasks in a certain lapse of time but always ensuring a minimum process quality. In the same way, communications must try to reduce the data traffic without excluding relevant information. The main objective of the paper is to present a dynamic configuration mechanism to adapt the sensor processing and communication to the client's requirements in the DCS. This paper describes an implementation of a smart resource based on a Red, Green, Blue, and Depth (RGBD) sensor in order to test the dynamic configuration mechanism presented.

An MPI-based MoSST core dynamics model

NASA Astrophysics Data System (ADS)

Jiang, Weiyuan; Kuang, Weijia

2008-09-01

Distributed systems are among the main cost-effective and expandable platforms for high-end scientific computing. Therefore scalable numerical models are important for effective use of such systems. In this paper, we present an MPI-based numerical core dynamics model for simulation of geodynamo and planetary dynamos, and for simulation of core-mantle interactions. The model is developed based on MPI libraries. Two algorithms are used for node-node communication: a "master-slave" architecture and a "divide-and-conquer" architecture. The former is easy to implement but not scalable in communication. The latter is scalable in both computation and communication. The model scalability is tested on Linux PC clusters with up to 128 nodes. This model is also benchmarked with a published numerical dynamo model solution.

Evaluation of components, subsystems, and networks for high rate, high frequency space communications

NASA Technical Reports Server (NTRS)

Kerczewski, Robert J.; Ivancic, William D.; Zuzek, John E.

1991-01-01

The development of new space communications technologies by NASA has included both commercial applications and space science requirements. NASA's Systems Integration, Test and Evaluation (SITE) Space Communication System Simulator is a hardware based laboratory simulator for evaluating space communications technologies at the component, subsystem, system, and network level, geared toward high frequency, high data rate systems. The SITE facility is well-suited for evaluation of the new technologies required for the Space Exploration Initiative (SEI) and advanced commercial systems. Described here are the technology developments and evaluation requirements for current and planned commercial and space science programs. Also examined are the capabilities of SITE, the past, present and planned future configurations of the SITE facility, and applications of SITE to evaluation of SEI technology.

A high-frequency warm shallow water acoustic communications channel model and measurements.

PubMed

Chitre, Mandar

2007-11-01

Underwater acoustic communication is a core enabling technology with applications in ocean monitoring using remote sensors and autonomous underwater vehicles. One of the more challenging underwater acoustic communication channels is the medium-range very shallow warm-water channel, common in tropical coastal regions. This channel exhibits two key features-extensive time-varying multipath and high levels of non-Gaussian ambient noise due to snapping shrimp-both of which limit the performance of traditional communication techniques. A good understanding of the communications channel is key to the design of communication systems. It aids in the development of signal processing techniques as well as in the testing of the techniques via simulation. In this article, a physics-based channel model for the very shallow warm-water acoustic channel at high frequencies is developed, which are of interest to medium-range communication system developers. The model is based on ray acoustics and includes time-varying statistical effects as well as non-Gaussian ambient noise statistics observed during channel studies. The model is calibrated and its accuracy validated using measurements made at sea.

Communication in Pipes Using Acoustic Modems that Provide Minimal Obstruction to Fluid Flow

NASA Technical Reports Server (NTRS)

Bar-Cohen, Yoseph (Inventor); Bao, Xiaoqi (Inventor); Sherrit, Stewart (Inventor); Archer, Eric D. (Inventor)

2016-01-01

A plurality of phased array acoustic communication devices are used to communicate data along a tubulation, such as a well. The phased array acoustic communication devices employ phased arrays of acoustic transducers, such as piezoelectric transducers, to direct acoustic energy in desired directions along the tubulation. The system is controlled by a computer-based controller. Information, including data and commands, is communicated using digital signaling.

Patients’ Data Management System Protected by Identity-Based Authentication and Key Exchange

PubMed Central

Rivero-García, Alexandra; Santos-González, Iván; Hernández-Goya, Candelaria; Caballero-Gil, Pino; Yung, Moti

2017-01-01

A secure and distributed framework for the management of patients’ information in emergency and hospitalization services is proposed here in order to seek improvements in efficiency and security in this important area. In particular, confidentiality protection, mutual authentication, and automatic identification of patients are provided. The proposed system is based on two types of devices: Near Field Communication (NFC) wristbands assigned to patients, and mobile devices assigned to medical staff. Two other main elements of the system are an intermediate server to manage the involved data, and a second server with a private key generator to define the information required to protect communications. An identity-based authentication and key exchange scheme is essential to provide confidential communication and mutual authentication between the medical staff and the private key generator through an intermediate server. The identification of patients is carried out through a keyed-hash message authentication code. Thanks to the combination of the aforementioned tools, a secure alternative mobile health (mHealth) scheme for managing patients’ data is defined for emergency and hospitalization services. Different parts of the proposed system have been implemented, including mobile application, intermediate server, private key generator and communication channels. Apart from that, several simulations have been performed, and, compared with the current system, significant improvements in efficiency have been observed. PMID:28362328

Patients' Data Management System Protected by Identity-Based Authentication and Key Exchange.

PubMed

Rivero-García, Alexandra; Santos-González, Iván; Hernández-Goya, Candelaria; Caballero-Gil, Pino; Yung, Moti

2017-03-31

A secure and distributed framework for the management of patients' information in emergency and hospitalization services is proposed here in order to seek improvements in efficiency and security in this important area. In particular, confidentiality protection, mutual authentication, and automatic identification of patients are provided. The proposed system is based on two types of devices: Near Field Communication (NFC) wristbands assigned to patients, and mobile devices assigned to medical staff. Two other main elements of the system are an intermediate server to manage the involved data, and a second server with a private key generator to define the information required to protect communications. An identity-based authentication and key exchange scheme is essential to provide confidential communication and mutual authentication between the medical staff and the private key generator through an intermediate server. The identification of patients is carried out through a keyed-hash message authentication code. Thanks to the combination of the aforementioned tools, a secure alternative mobile health (mHealth) scheme for managing patients' data is defined for emergency and hospitalization services. Different parts of the proposed system have been implemented, including mobile application, intermediate server, private key generator and communication channels. Apart from that, several simulations have been performed, and, compared with the current system, significant improvements in efficiency have been observed.

Developing and Evaluating Communication Strategies to Support Informed Decisions and Practice Based on Evidence (DECIDE): protocol and preliminary results.

PubMed

Treweek, Shaun; Oxman, Andrew D; Alderson, Philip; Bossuyt, Patrick M; Brandt, Linn; Brożek, Jan; Davoli, Marina; Flottorp, Signe; Harbour, Robin; Hill, Suzanne; Liberati, Alessandro; Liira, Helena; Schünemann, Holger J; Rosenbaum, Sarah; Thornton, Judith; Vandvik, Per Olav; Alonso-Coello, Pablo

2013-01-09

Healthcare decision makers face challenges when using guidelines, including understanding the quality of the evidence or the values and preferences upon which recommendations are made, which are often not clear. GRADE is a systematic approach towards assessing the quality of evidence and the strength of recommendations in healthcare. GRADE also gives advice on how to go from evidence to decisions. It has been developed to address the weaknesses of other grading systems and is now widely used internationally. The Developing and Evaluating Communication Strategies to Support Informed Decisions and Practice Based on Evidence (DECIDE) consortium (http://www.decide-collaboration.eu/), which includes members of the GRADE Working Group and other partners, will explore methods to ensure effective communication of evidence-based recommendations targeted at key stakeholders: healthcare professionals, policymakers, and managers, as well as patients and the general public. Surveys and interviews with guideline producers and other stakeholders will explore how presentation of the evidence could be improved to better meet their information needs. We will collect further stakeholder input from advisory groups, via consultations and user testing; this will be done across a wide range of healthcare systems in Europe, North America, and other countries. Targeted communication strategies will be developed, evaluated in randomized trials, refined, and assessed during the development of real guidelines. Results of the DECIDE project will improve the communication of evidence-based healthcare recommendations. Building on the work of the GRADE Working Group, DECIDE will develop and evaluate methods that address communication needs of guideline users. The project will produce strategies for communicating recommendations that have been rigorously evaluated in diverse settings, and it will support the transfer of research into practice in healthcare systems globally.

75 FR 2117 - Privacy Act of 1974; System of Records

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-14

... Force, 30 Space Communications Squadron, Building 12000, Room 104, 867 Washington Ave., Suite 205... Wing Space Communications Squadron, 867 Washington Avenue, Suite 200-1, Vandenberg Air Force Base... Superintendent, 30 Space Wing Command Post 867 Washington Ave, Suite 205, Vandenberg Air Force Base, California...

Heavy truck pre-crash scenarios for safety applications based on vehicle-to-vehicle communications

DOT National Transportation Integrated Search

2014-06-01

This report describes pre-crash scenarios involving at least one heavy truck (gross vehicle weight rating greater than 10,000 pounds), which might be addressed with crash-imminent warning systems based on short range vehicle-to-vehicle (V2V) communic...

Scheduling algorithm for data relay satellite optical communication based on artificial intelligent optimization

NASA Astrophysics Data System (ADS)

Zhao, Wei-hu; Zhao, Jing; Zhao, Shang-hong; Li, Yong-jun; Wang, Xiang; Dong, Yi; Dong, Chen

2013-08-01

Optical satellite communication with the advantages of broadband, large capacity and low power consuming broke the bottleneck of the traditional microwave satellite communication. The formation of the Space-based Information System with the technology of high performance optical inter-satellite communication and the realization of global seamless coverage and mobile terminal accessing are the necessary trend of the development of optical satellite communication. Considering the resources, missions and restraints of Data Relay Satellite Optical Communication System, a model of optical communication resources scheduling is established and a scheduling algorithm based on artificial intelligent optimization is put forwarded. According to the multi-relay-satellite, multi-user-satellite, multi-optical-antenna and multi-mission with several priority weights, the resources are scheduled reasonable by the operation: "Ascertain Current Mission Scheduling Time" and "Refresh Latter Mission Time-Window". The priority weight is considered as the parameter of the fitness function and the scheduling project is optimized by the Genetic Algorithm. The simulation scenarios including 3 relay satellites with 6 optical antennas, 12 user satellites and 30 missions, the simulation result reveals that the algorithm obtain satisfactory results in both efficiency and performance and resources scheduling model and the optimization algorithm are suitable in multi-relay-satellite, multi-user-satellite, and multi-optical-antenna recourses scheduling problem.

Streetlight Control System Based on Wireless Communication over DALI Protocol

PubMed Central

Bellido-Outeiriño, Francisco José; Quiles-Latorre, Francisco Javier; Moreno-Moreno, Carlos Diego; Flores-Arias, José María; Moreno-García, Isabel; Ortiz-López, Manuel

2016-01-01

Public lighting represents a large part of the energy consumption of towns and cities. Efficient management of public lighting can entail significant energy savings. This work presents a smart system for managing public lighting networks based on wireless communication and the DALI protocol. Wireless communication entails significant economic savings, as there is no need to install new wiring and visual impacts and damage to the facades of historical buildings in city centers are avoided. The DALI protocol uses bidirectional communication with the ballast, which allows its status to be controlled and monitored at all times. The novelty of this work is that it tackles all aspects related to the management of public lighting: a standard protocol, DALI, was selected to control the ballast, a wireless node based on the IEEE 802.15.4 standard with a DALI interface was designed, a network layer that considers the topology of the lighting network has been developed, and lastly, some user-friendly applications for the control and maintenance of the system by the technical crews of the different towns and cities have been developed. PMID:27128923

Deployable Propulsion, Power and Communications Systems for Solar System Exploration

NASA Technical Reports Server (NTRS)

Johnson, L.; Carr, J.; Boyd, D.

2017-01-01

NASA is developing thin-film based, deployable propulsion, power, and communication systems for small spacecraft that could provide a revolutionary new capability allowing small spacecraft exploration of the solar system. By leveraging recent advancements in thin films, photovoltaics, and miniaturized electronics, new mission-level capabilities will be enabled aboard lower-cost small spacecraft instead of their more expensive, traditional counterparts, enabling a new generation of frequent, inexpensive deep space missions. Specifically, thin-film technologies are allowing the development and use of solar sails for propulsion, small, lightweight photovoltaics for power, and omnidirectional antennas for communication.

Economic benefits of the Space Station to commercial communication satellite operators

NASA Technical Reports Server (NTRS)

Price, Kent M.; Dixson, John E.; Weyandt, Charles J.

1987-01-01

The economic and financial aspects of newly defined space-based activities, procedures, and operations (APOs) and associated satellite system designs are presented that have the potential to improve economic performance of future geostationary communications satellites. Launch insurance, launch costs, and the economics of APOs are examined. Retrieval missions and various Space Station scenarios are addressed. The potential benefits of the new APOs to the commercial communications satellite system operator are quantified.

Retro-detective control structures for free-space optical communication links.

PubMed

Jin, Xian; Barg, Jason E; Holzman, Jonathan F

2009-12-21

A corner-cube-based retro-detection photocell is introduced. The structure consists of three independent and mutually perpendicular photodiodes (PDs), whose differential photocurrents can be used to probe the alignment state of incident beams. These differential photocurrents are used in an actively-controlled triangulation procedure to optimize the communication channel alignment in a free-space optical (FSO) system. The active downlink and passive uplink communication capabilities of this system are demonstrated.

Environmental Assessment for the National Museum of the United States Air Force Addition, Wright-Patterson Air Force Base, Ohio

DTIC Science & Technology

2013-02-01

telephone, local computer systems, long-haul communications , and land mobile radio systems (WPAFB 2001). There are over 100 miles of communication cable...10. SPONSOR/MONITOR’S ACRONYM(S) 11 . SPONSOR/MONITOR’S REPORT NUMBER(S) 12. DISTRIBUTION/AVAILABILITY STATEMENT Approved for public release...Air Force technologies and would include unique characteristics in design, propulsion, payload capacity, buman factors, communication , range, speed

47 CFR 22.705 - Rural radiotelephone system configuration.

Code of Federal Regulations, 2010 CFR

2010-10-01

... not feasible, rural subscriber stations may be authorized to communicate with and through a base... configuration. Stations in the Rural Radiotelephone Service are authorized to communicate as follows: (a) Rural subscriber stations are authorized to communicate with and through the central office station(s) with which...

Communication: The Study of Human Interaction.

ERIC Educational Resources Information Center

Mortensen, C. David

Designed to provide a comprehensive and broadly based introduction to the study of human communication, this book presents the concept of communication as interrelated constituent processes that operate at varying levels of complexity and acquire significance only in the context of larger intrapersonal, interpersonal, or socio-cultural systems of…

Using Technology To Communicate, Cooperate and Collaborate.

ERIC Educational Resources Information Center

Holland, David G.

This paper outlines a process implemented at Mott Community College (Michigan) for building technology-based systems that would encourage collaboration among the staff. The first goal was communication, which included using the following technology to allow people to communicate and to make information available: e-mail, calendaring,…

Effects of atmospheric turbulence on microwave and millimeter wave satellite communications systems. [attenuation statistics and antenna design

NASA Technical Reports Server (NTRS)

Devasirvatham, D. M. J.; Hodge, D. B.

1981-01-01

A model of the microwave and millimeter wave link in the presence of atmospheric turbulence is presented with emphasis on satellite communications systems. The analysis is based on standard methods of statistical theory. The results are directly usable by the design engineer.

Information and Communication Technology in the Israeli Educational System: Past, Present and Future.

ERIC Educational Resources Information Center

Katz, Yaacov J.

2002-01-01

Describes the development of the use of information and communication technology (ICT) in the Israeli educational system. Discusses a behaviorist approach to computer assisted instruction; open-ended courseware; constructivist approaches to multimedia, including simulations, modeling, and virtual reality; technology-based distance learning; and…

7 CFR 1724.54 - Requirements for RUS approval of plans and specifications.

Code of Federal Regulations, 2012 CFR

2012-01-01

... specifications for transmission construction projects which are not based on RUS approved line design data or do...) Communications and control facilities. (1) This paragraph (g) covers microwave and powerline carrier communications systems, load control, and supervisory control and data acquisition (SCADA) systems. (2) The...

7 CFR 1724.54 - Requirements for RUS approval of plans and specifications.

Code of Federal Regulations, 2014 CFR

2014-01-01

... specifications for transmission construction projects which are not based on RUS approved line design data or do...) Communications and control facilities. (1) This paragraph (g) covers microwave and powerline carrier communications systems, load control, and supervisory control and data acquisition (SCADA) systems. (2) The...

7 CFR 1724.54 - Requirements for RUS approval of plans and specifications.

Code of Federal Regulations, 2013 CFR

2013-01-01

... specifications for transmission construction projects which are not based on RUS approved line design data or do...) Communications and control facilities. (1) This paragraph (g) covers microwave and powerline carrier communications systems, load control, and supervisory control and data acquisition (SCADA) systems. (2) The...

Information Communication Highways in the 1990s: An Analysis of Their Potential Impact on Library Automation.

ERIC Educational Resources Information Center

Kibirige, Harry M.

1991-01-01

Discussion of the potential effects of fiber optic-based communication technology on information networks and systems design highlights library automation. Topics discussed include computers and telecommunications systems, the importance of information in national economies, microcomputers, local area networks (LANs), national computer networks,…

Training Paraprofessionals to Implement the Picture Exchange Communication System (PECS)

ERIC Educational Resources Information Center

Sloman, Glenn Matthew

2010-01-01

Based on Skinner's "Verbal Behavior" (1957), the picture exchange communication system (PECS) was designed to teach children with autism functional verbal behavior. Much research has demonstrated the effectiveness and efficiency of PECS in building verbal behavior. However, because PECS training is typically presented in a group format and later…

Modeling and Analysis of Space Based Transceivers

NASA Technical Reports Server (NTRS)

Moore, Michael S.; Price, Jeremy C.; Reinhart, Richard; Liebetreu, John; Kacpura, Tom J.

2005-01-01

This paper presents the tool chain, methodology, and results of an on-going study being performed jointly by Space Communication Experts at NASA Glenn Research Center (GRC), General Dynamics C4 Systems (GD), and Southwest Research Institute (SwRI). The team is evaluating the applicability and tradeoffs concerning the use of Software Defined Radio (SDR) technologies for Space missions. The Space Telecommunications Radio Systems (STRS) project is developing an approach toward building SDR-based transceivers for space communications applications based on an accompanying software architecture that can be used to implement transceivers for NASA space missions. The study is assessing the overall cost and benefit of employing SDR technologies in general, and of developing a software architecture standard for its space SDR transceivers. The study is considering the cost and benefit of existing architectures, such as the Joint Tactical Radio Systems (JTRS) Software Communications Architecture (SCA), as well as potential new space-specific architectures.

A PC-based bus monitor program for use with the transport systems research vehicle RS-232 communication interfaces

NASA Technical Reports Server (NTRS)

Easley, Wesley C.

1991-01-01

Experiment critical use of RS-232 data busses in the Transport Systems Research Vehicle (TSRV) operated by the Advanced Transport Operating Systems Program Office at the NASA Langley Research Center has recently increased. Each application utilizes a number of nonidentical computer and peripheral configurations and requires task specific software development. To aid these development tasks, an IBM PC-based RS-232 bus monitoring system was produced. It can simultaneously monitor two communication ports of a PC or clone, including the nonstandard bus expansion of the TSRV Grid laptop computers. Display occurs in a separate window for each port's input with binary display being selectable. A number of other features including binary log files, screen capture to files, and a full range of communication parameters are provided.

Space Based Communications

NASA Technical Reports Server (NTRS)

Simpson, James; Denson, Erik; Valencia, Lisa; Birr, Richard

2003-01-01

Current space lift launches on the Eastern and Western Range require extensive ground-based real-time tracking, communications and command/control systems. These are expensive to maintain and operate and cover only limited geographical areas. Future spaceports will require new technologies to provide greater launch and landing opportunities, support simultaneous missions, and offer enhanced decision support models and simulation capabilities. These ranges must also have lower costs and reduced complexity while continuing to provide unsurpassed safety to the public, flight crew, personnel, vehicles and facilities. Commercial and government space-based assets for tracking and communications offer many attractive possibilities to help achieve these goals. This paper describes two NASA proof-of-concept projects that seek-to exploit the advantages of a space-based range: Iridium Flight Modem and Space-Based Telemetry and Range Safety (STARS). Iridium Flight Modem uses the commercial satellite system Iridium for extremely low cost, low rate two-way communications and has been successfully tested on four aircraft flights. A sister project at Goddard Space Flight Center's (GSFC) Wallops Flight Facility (WFF) using the Globalstar system has been tested on one rocket. The basic Iridium Flight Modem system consists of a L1 carrier Coarse/Acquisition (C/A)-Code Global Positioning System (GPS) receiver, an on-board computer, and a standard commercial satellite modem and antennas. STARS uses the much higher data rate NASA owned Tracking and Data Relay Satellite System (TDRSS), a C/A-Code GPS receiver, an experimental low-power transceiver, custom built command and data handler processor, and digitized flight termination system (FTS) commands. STARS is scheduled to fly on an F-15 at Dryden Flight Research Center in the spring of 2003, with follow-on tests over the next several years.

An Embedded Rule-Based Diagnostic Expert System in Ada

NASA Technical Reports Server (NTRS)

Jones, Robert E.; Liberman, Eugene M.

1992-01-01

Ada is becoming an increasingly popular programming language for large Government-funded software projects. Ada with it portability, transportability, and maintainability lends itself well to today's complex programming environment. In addition, expert systems have also assumed a growing role in providing human-like reasoning capability expertise for computer systems. The integration is discussed of expert system technology with Ada programming language, especially a rule-based expert system using an ART-Ada (Automated Reasoning Tool for Ada) system shell. NASA Lewis was chosen as a beta test site for ART-Ada. The test was conducted by implementing the existing Autonomous Power EXpert System (APEX), a Lisp-based power expert system, in ART-Ada. Three components, the rule-based expert systems, a graphics user interface, and communications software make up SMART-Ada (Systems fault Management with ART-Ada). The rules were written in the ART-Ada development environment and converted to Ada source code. The graphics interface was developed with the Transportable Application Environment (TAE) Plus, which generates Ada source code to control graphics images. SMART-Ada communicates with a remote host to obtain either simulated or real data. The Ada source code generated with ART-Ada, TAE Plus, and communications code was incorporated into an Ada expert system that reads the data from a power distribution test bed, applies the rule to determine a fault, if one exists, and graphically displays it on the screen. The main objective, to conduct a beta test on the ART-Ada rule-based expert system shell, was achieved. The system is operational. New Ada tools will assist in future successful projects. ART-Ada is one such tool and is a viable alternative to the straight Ada code when an application requires a rule-based or knowledge-based approach.

Economic communication model set

NASA Astrophysics Data System (ADS)

Zvereva, Olga M.; Berg, Dmitry B.

2017-06-01

This paper details findings from the research work targeted at economic communications investigation with agent-based models usage. The agent-based model set was engineered to simulate economic communications. Money in the form of internal and external currencies was introduced into the models to support exchanges in communications. Every model, being based on the general concept, has its own peculiarities in algorithm and input data set since it was engineered to solve the specific problem. Several and different origin data sets were used in experiments: theoretic sets were estimated on the basis of static Leontief's equilibrium equation and the real set was constructed on the basis of statistical data. While simulation experiments, communication process was observed in dynamics, and system macroparameters were estimated. This research approved that combination of an agent-based and mathematical model can cause a synergetic effect.

Air traffic management system design using satellite based geo-positioning and communications assets

NASA Technical Reports Server (NTRS)

Horkin, Phil

1995-01-01

The current FAA and ICAO FANS vision of Air Traffic Management will transition the functions of Communications, Navigation, and Surveillance to satellite based assets in the 21st century. Fundamental to widespread acceptance of this vision is a geo-positioning system that can provide worldwide access with best case differential GPS performance, but without the associated problems. A robust communications capability linking-up aircraft and towers to meet the voice and data requirements is also essential. The current GPS constellation does not provide continuous global coverage with a sufficient number of satellites to meet the precision landing requirements as set by the world community. Periodic loss of the minimum number of satellites in view creates an integrity problem, which prevents GPS from becoming the primary system for navigation. Furthermore, there is reluctance on the part of many countries to depend on assets like GPS and GLONASS which are controlled by military communities. This paper addresses these concerns and provides a system solving the key issues associated with navigation, automatic dependent surveillance, and flexible communications. It contains an independent GPS-like navigation system with 27 satellites providing global coverage with a minimum of six in view at all times. Robust communications is provided by a network of TDMA/FDMA communications payloads contained on these satellites. This network can support simultaneous communications for up to 30,000 links, nearly enough to simultaneously support three times the current global fleet of jumbo air passenger aircraft. All of the required hardware is directly traceable to existing designs.

The Role of the Built Environment: How Decentralized Nurse Stations Shape Communication, Patient Care Processes, and Patient Outcomes.

PubMed

Real, Kevin; Bardach, Shoshana H; Bardach, David R

2017-12-01

Increasingly, health communication scholars are attending to how hospital built environments shape communication, patient care processes, and patient outcomes. This multimethod study was conducted on two floors of a newly designed urban hospital. Nine focus groups interviews were conducted with 35 health care professionals from 10 provider groups. Seven of the groups were homogeneous by profession or level: nursing (three groups), nurse managers (two groups), and one group each of nurse care technicians ("techs") and physicians. Two mixed groups were comprised of staff from pharmacy, occupational therapy, patient care facilitators, physical therapy, social work, and pastoral care. Systematic qualitative analysis was conducted using a conceptual framework based on systems theory and prior health care design and communication research. Additionally, quantitative modeling was employed to assess walking distances in two different hospital designs. Results indicate nurses walked significantly more in the new hospital environment. Qualitative analysis revealed three insights developed in relationship to system structures, processes, and outcomes. First, decentralized nurse stations changed system interdependencies by reducing nurse-to-nurse interactions and teamwork while heightening nurse interdependencies and teamwork with other health care occupations. Second, many nursing-related processes remained centralized while nurse stations were decentralized, creating systems-based problems for nursing care. Third, nursing communities of practices were adversely affected by the new design. Implications of this study suggest that nurse station design shapes communication, patient care processes, and patient outcomes. Further, it is important to understand how the built environment, often treated as invisible in communication research, is crucial to understanding communication within complex health care systems.

A Hospital Local Area Communication Network—The First Year's Experience

PubMed Central

Simborg, D. W.; Chadwick, M.; Whiting-O'Keefe, Q. E.; Tolchin, S. G.; Stewart, R. L.; Kahn, S. A.; Bergan, E. S.; Gafke, G. P.

1982-01-01

A local area communications network has been implemented at the University of California, San Francisco Hospital to integrate major components of the hospital's information system. This microprocessor-based network technology was developed by The Applied Physics Laboratory of the Johns Hopkins University. The first year's experience has demonstrated the basic feasibility of this technology in simplifying the integration of diverse hardware and software systems. Four minicomputer-based UCSF systems now use the network to synchronize key patient identification and registration information among the systems. Clinical uses of the network will begin during the second year of the project.

Engineered cell-cell communication via DNA messaging

PubMed Central

2012-01-01

Background Evolution has selected for organisms that benefit from genetically encoded cell-cell communication. Engineers have begun to repurpose elements of natural communication systems to realize programmed pattern formation and coordinate other population-level behaviors. However, existing engineered systems rely on system-specific small molecules to send molecular messages among cells. Thus, the information transmission capacity of current engineered biological communication systems is physically limited by specific biomolecules that are capable of sending only a single message, typically “regulate transcription.” Results We have engineered a cell-cell communication platform using bacteriophage M13 gene products to autonomously package and deliver heterologous DNA messages of varying lengths and encoded functions. We demonstrate the decoupling of messages from a common communication channel via the autonomous transmission of various arbitrary genetic messages. Further, we increase the range of engineered DNA messaging across semisolid media by linking message transmission or receipt to active cellular chemotaxis. Conclusions We demonstrate decoupling of a communication channel from message transmission within engineered biological systems via the autonomous targeted transduction of user-specified heterologous DNA messages. We also demonstrate that bacteriophage M13 particle production and message transduction occurs among chemotactic bacteria. We use chemotaxis to improve the range of DNA messaging, increasing both transmission distance and communication bit rates relative to existing small molecule-based communication systems. We postulate that integration of different engineered cell-cell communication platforms will allow for more complex spatial programming of dynamic cellular consortia. PMID:22958599

Optical satellite communications in Europe

NASA Astrophysics Data System (ADS)

Sodnik, Zoran; Lutz, Hanspeter; Furch, Bernhard; Meyer, Rolf

2010-02-01

This paper describes optical satellite communication activities based on technology developments, which started in Europe more than 30 years ago and led in 2001 to the world-first optical inter-satellite communication link experiment (SILEX). SILEX proved that optical communication technologies can be reliably mastered in space and in 2006 the Japanese Space Agency (JAXA) joined the optical inter-satellite experiment from their own satellite. Since 2008 the German Space Agency (DLR) is operating an inter-satellite link between the NFIRE and TerraSAR-X satellites based on a second generation of laser communication technology, which will be used for the new European Data Relay Satellite (EDRS) system to be deployed in 2013.

Knowledge information management toolkit and method

DOEpatents

Hempstead, Antoinette R.; Brown, Kenneth L.

2006-08-15

A system is provided for managing user entry and/or modification of knowledge information into a knowledge base file having an integrator support component and a data source access support component. The system includes processing circuitry, memory, a user interface, and a knowledge base toolkit. The memory communicates with the processing circuitry and is configured to store at least one knowledge base. The user interface communicates with the processing circuitry and is configured for user entry and/or modification of knowledge pieces within a knowledge base. The knowledge base toolkit is configured for converting knowledge in at least one knowledge base from a first knowledge base form into a second knowledge base form. A method is also provided.

A new chaotic communication scheme based on adaptive synchronization.

PubMed

Xiang-Jun, Wu

2006-12-01

A new chaotic communication scheme using adaptive synchronization technique of two unified chaotic systems is proposed. Different from the existing secure communication methods, the transmitted signal is modulated into the parameter of chaotic systems. The adaptive synchronization technique is used to synchronize two identical chaotic systems embedded in the transmitter and the receiver. It is assumed that the parameter of the receiver system is unknown. Based on the Lyapunov stability theory, an adaptive control law is derived to make the states of two identical unified chaotic systems with unknown system parameters asymptotically synchronized; thus the parameter of the receiver system is identified. Then the recovery of the original information signal in the receiver is successfully achieved on the basis of the estimated parameter. It is noticed that the time required for recovering the information signal and the accuracy of the recovered signal very sensitively depends on the frequency of the information signal. Numerical results have verified the effectiveness of the proposed scheme.

The challenges of emerging HISs in bridging the communication gaps among physicians and nurses in China: an interview study.

PubMed

Wen, Dong; Zhang, Xingting; Wan, Jie; Fu, Jing; Lei, Jianbo

2017-06-12

To explore the current situation, existing problems and possible causes of said problems with regards to physician-nurse communication under an environment of increasingly widespread usage of Hospital Information Systems and to seek out new potential strategies in information technology to improve physician-nurse communication. Semi-structured interviews were conducted with 20 physicians and nurses in five leading tertiary grade A hospitals in Beijing, China (two physicians and two nurses in each hospital). The interviews primarily included three aspects comprising the current situation and problems of clinical physician-nurse communication, the application and problems of Hospital Information Systems, and assessments on the improvement of physician-nurse communication through the usage of information technology. The inductive conventional content analysis approach was employed. (1) Physicians and nurses are generally quite satisfied with the current situation of communication. However, the information needs of nurses are prone to being overlooked, and the communication methods are primarily synchronous communication such as face-to-face and phone communication. (2) Hospital Information Systems are gradually being used for physician-nurse communication; in the meantime, physicians and nurses face challenges with regards to the improvement of physician-nurse communication through the usage of information technology. Challenges differ based on the different stages of using the system and the different levels of understanding of physicians and nurses towards information technology. Their dissatisfaction mainly deals with system errors and the level of convenience in using the system. (3) In-depth interviews found that in general, physicians and nurses have a strong interest and trust in improving physician-nurse communication through appropriate information technology, e.g., communication methods such as information reminders for physicians and nurses through mobile devices and instant voice-to-text conversion methods. There are objective risks in physician-nurse communication in Chinese hospitals, and clinical information systems lack solutions to the relevant problems. Developing a dedicated, mobile, quick and convenient module for physician-nurse communication within existing hospital information system with automatic reminders for important information that segregates between synchronous and asynchronous communication according to the different types of information could help improve physician-nurse communication.

It's not about pager replacement: an in-depth look at the interprofessional nature of communication in healthcare.

PubMed

Quan, Sherman D; Wu, Robert C; Rossos, Peter G; Arany, Teri; Groe, Silvi; Morra, Dante; Wong, Brian M; Cavalcanti, Rodrigo; Coke, William; Lau, Francis Y

2013-03-01

Institutions have tried to replace the use of numeric pagers for clinical communication by implementing health information technology (HIT) solutions. However, failing to account for the sociotechnical aspects of HIT or the interplay of technology with existing clinical workflow, culture, and social interactions may create other unintended consequences. To evaluate a Web-based messaging system that allows asynchronous communication between health providers and identify the unintended consequences associated with implementing such technology. Intervention-a Web-based messaging system at the University Health Network to replace numeric paging practices in May 2010. The system facilitated clinical communication on the medical wards for coordinating patient care. Study design-pre-post mixed methods utilizing both quantitative and qualitative measures. Five residents, 8 nurses, 2 pharmacists, and 2 social workers were interviewed. Pre-post interruption-15 residents from 5 clinical teams in both periods. The study compared the type of messages sent to physicians before and after implementation of the Web-based messaging system; a constant comparative analysis of semistructured interviews was used to generate key themes related to unintended consequences. Interruptions increased 233%, from 3 pages received per resident per day pre-implementation to 10 messages received per resident per day post-implementation. Key themes relating to unintended consequences that emerged from the interviews included increase in interruptions, accountability, and tactics to improve personal productivity. Meaningful improvements in clinical communication can occur but require more than just replacing pagers. Introducing HIT without addressing the sociotechnical aspects of HIT that underlie clinical communication can lead to unintended consequences. Copyright © 2013 Society of Hospital Medicine.

Channel capacity of OAM based FSO communication systems with partially coherent Bessel-Gaussian beams in anisotropic turbulence

NASA Astrophysics Data System (ADS)

Peng, Juan; Zhang, Li; Zhang, Kecheng; Ma, Junxian

2018-07-01

Based on the Rytov approximation theory, the transmission model of an orbital angular momentum (OAM)-carrying partially coherent Bessel-Gaussian (BG) beams propagating in weak anisotropic turbulence is established. The corresponding analytical expression of channel capacity is presented. Influences of anisotropic turbulence parameters and beam parameters on channel capacity of OAM-based free-space optical (FSO) communication systems are discussed in detail. The results indicate channel capacity increases with increasing of almost all of the parameters except for transmission distance. Raising the values of some parameters such as wavelength, propagation altitude and non-Kolmogorov power spectrum index, would markedly improve the channel capacity. In addition, we evaluate the channel capacity of Laguerre-Gaussian (LG) beams and partially coherent BG beams in anisotropic turbulence. It indicates that partially coherent BG beams are better light sources candidates for mitigating the influences of anisotropic turbulence on channel capacity of OAM-based FSO communication systems.

Use of a Hands Free, Instantaneous, Closed-Loop Communication Device Improves Perception of Communication and Workflow Integration in an Academic Teaching Hospital: A Pilot Study.

PubMed

Fang, Daniel Z; Patil, Teja; Belitskaya-Levy, Ilana; Yeung, Marianne; Posley, Keith; Allaudeen, Nazima

2017-11-17

Efficient and effective communication between providers is critical to quality patient care within a hospital system. Hands free communication devices (HFCD) allow instantaneous, closed-loop communication between physicians and other members of a multidisciplinary team, providing a communication advantage over traditional pager systems. HFCD have been shown to decrease emergency room interruptions, improve nursing communication, improve speed of information flow, and eliminate health care waste. We evaluated the integration of an HFCD with an existing alphanumeric paging system on an acute inpatient medicine service. We conducted a prospective, observational, survey-based study over twenty-four weeks in an academic tertiary care center with attending physicians and residents. Our intervention involved the implementation of an HFCD alongside the existing paging system. Fifty-six pre and post surveys evaluated the perception of improvement in communication and the integration of the HFCD into existing workflow. We saw significant improvements in the ability of an HFCD to help physicians communicate thoughts clearly, communicate thoughts effectively, reach team members, reach ancillary staff, and stay informed about patients. Physicians also reported better workflow integration during admissions, rounds, discharge, and teaching sessions. Qualitative data from post surveys demonstrated that the greatest strengths of the HFCD included the ability to reach colleagues and staff quickly, provide instant access to individuals of the care team, and improve overall communication. Integration of an instantaneous, hands free, closed loop communication system alongside the existing pager system can provide improvements in the perceptions of communication and workflow integration in an academic medicine service. Future studies are needed to correlate these subjective findings with objective measures of quality and safety.

DAZZLE project: UAV to ground communication system using a laser and a modulated retro-reflector

NASA Astrophysics Data System (ADS)

Thueux, Yoann; Avlonitis, Nicholas; Erry, Gavin

2014-10-01

The advent of the Unmanned Aerial Vehicle (UAV) has generated the need for reduced size, weight and power (SWaP) requirements for communications systems with a high data rate, enhanced security and quality of service. This paper presents the current results of the DAZZLE project run by Airbus Group Innovations. The specifications, integration steps and initial performance of a UAV to ground communication system using a laser and a modulated retro-reflector are detailed. The laser operates at the wavelength of 1550nm and at power levels that keep it eye safe. It is directed using a FLIR pan and tilt unit driven by an image processing-based system that tracks the UAV in flight at a range of a few kilometers. The modulated retro-reflector is capable of a data rate of 20Mbps over short distances, using 200mW of electrical power. The communication system was tested at the Pershore Laser Range in July 2014. Video data from a flying Octocopter was successfully transmitted over 1200m. During the next phase of the DAZZLE project, the team will attempt to produce a modulated retro-reflector capable of 1Gbps in partnership with the research institute Acreo1 based in Sweden. A high speed laser beam steering capability based on a Spatial Light Modulator will also be added to the system to improve beam pointing accuracy.

Analysis of Vehicle-Based Security Operations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carter, Jason M; Paul, Nate R

Vehicle-to-vehicle (V2V) communications promises to increase roadway safety by providing each vehicle with 360 degree situational awareness of other vehicles in proximity, and by complementing onboard sensors such as radar or camera in detecting imminent crash scenarios. In the United States, approximately three hundred million automobiles could participate in a fully deployed V2V system if Dedicated Short-Range Communication (DSRC) device use becomes mandatory. The system s reliance on continuous communication, however, provides a potential means for unscrupulous persons to transmit false data in an attempt to cause crashes, create traffic congestion, or simply render the system useless. V2V communications mustmore » be highly scalable while retaining robust security and privacy preserving features to meet the intra-vehicle and vehicle-to-infrastructure communication requirements for a growing vehicle population. Oakridge National Research Laboratory is investigating a Vehicle-Based Security System (VBSS) to provide security and privacy for a fully deployed V2V and V2I system. In the VBSS an On-board Unit (OBU) generates short-term certificates and signs Basic Safety Messages (BSM) to preserve privacy and enhance security. This work outlines a potential VBSS structure and its operational concepts; it examines how a vehicle-based system might feasibly provide security and privacy, highlights remaining challenges, and explores potential mitigations to address those challenges. Certificate management alternatives that attempt to meet V2V security and privacy requirements have been examined previously by the research community including privacy-preserving group certificates, shared certificates, and functional encryption. Due to real-world operational constraints, adopting one of these approaches for VBSS V2V communication is difficult. Timely misbehavior detection and revocation are still open problems for any V2V system. We explore the alternative approaches that may be applicable to a VBSS, and suggest some additional research directions in order to find a practical solution that appropriately addresses security and privacy.« less

An Experimental Realization of a Chaos-Based Secure Communication Using Arduino Microcontrollers

PubMed Central

Zapateiro De la Hoz, Mauricio; Vidal, Yolanda

2015-01-01

Security and secrecy are some of the important concerns in the communications world. In the last years, several encryption techniques have been proposed in order to improve the secrecy of the information transmitted. Chaos-based encryption techniques are being widely studied as part of the problem because of the highly unpredictable and random-look nature of the chaotic signals. In this paper we propose a digital-based communication system that uses the logistic map which is a mathematically simple model that is chaotic under certain conditions. The input message signal is modulated using a simple Delta modulator and encrypted using a logistic map. The key signal is also encrypted using the same logistic map with different initial conditions. In the receiver side, the binary-coded message is decrypted using the encrypted key signal that is sent through one of the communication channels. The proposed scheme is experimentally tested using Arduino shields which are simple yet powerful development kits that allows for the implementation of the communication system for testing purposes. PMID:26413563

SpecialNet. A National Computer-Based Communications Network.

ERIC Educational Resources Information Center

Morin, Alfred J.

1986-01-01

"SpecialNet," a computer-based communications network for educators at all administrative levels, has been established and is managed by National Systems Management, Inc. Users can send and receive electronic mail, share information on electronic bulletin boards, participate in electronic conferences, and send reports and other documents to each…

Ratiometric Decoding of Pheromones for a Biomimetic Infochemical Communication System.

PubMed

Wei, Guangfen; Thomas, Sanju; Cole, Marina; Rácz, Zoltán; Gardner, Julian W

2017-10-30

Biosynthetic infochemical communication is an emerging scientific field employing molecular compounds for information transmission, labelling, and biochemical interfacing; having potential application in diverse areas ranging from pest management to group coordination of swarming robots. Our communication system comprises a chemoemitter module that encodes information by producing volatile pheromone components and a chemoreceiver module that decodes the transmitted ratiometric information via polymer-coated piezoelectric Surface Acoustic Wave Resonator (SAWR) sensors. The inspiration for such a system is based on the pheromone-based communication between insects. Ten features are extracted from the SAWR sensor response and analysed using multi-variate classification techniques, i.e., Linear Discriminant Analysis (LDA), Probabilistic Neural Network (PNN), and Multilayer Perception Neural Network (MLPNN) methods, and an optimal feature subset is identified. A combination of steady state and transient features of the sensor signals showed superior performances with LDA and MLPNN. Although MLPNN gave excellent results reaching 100% recognition rate at 400 s, over all time stations PNN gave the best performance based on an expanded data-set with adjacent neighbours. In this case, 100% of the pheromone mixtures were successfully identified just 200 s after they were first injected into the wind tunnel. We believe that this approach can be used for future chemical communication employing simple mixtures of airborne molecules.

Ratiometric Decoding of Pheromones for a Biomimetic Infochemical Communication System

PubMed Central

Wei, Guangfen; Thomas, Sanju; Cole, Marina; Rácz, Zoltán

2017-01-01

Biosynthetic infochemical communication is an emerging scientific field employing molecular compounds for information transmission, labelling, and biochemical interfacing; having potential application in diverse areas ranging from pest management to group coordination of swarming robots. Our communication system comprises a chemoemitter module that encodes information by producing volatile pheromone components and a chemoreceiver module that decodes the transmitted ratiometric information via polymer-coated piezoelectric Surface Acoustic Wave Resonator (SAWR) sensors. The inspiration for such a system is based on the pheromone-based communication between insects. Ten features are extracted from the SAWR sensor response and analysed using multi-variate classification techniques, i.e., Linear Discriminant Analysis (LDA), Probabilistic Neural Network (PNN), and Multilayer Perception Neural Network (MLPNN) methods, and an optimal feature subset is identified. A combination of steady state and transient features of the sensor signals showed superior performances with LDA and MLPNN. Although MLPNN gave excellent results reaching 100% recognition rate at 400 s, over all time stations PNN gave the best performance based on an expanded data-set with adjacent neighbours. In this case, 100% of the pheromone mixtures were successfully identified just 200 s after they were first injected into the wind tunnel. We believe that this approach can be used for future chemical communication employing simple mixtures of airborne molecules. PMID:29084158

Assessing distractors and teamwork during surgery: developing an event-based method for direct observation.

PubMed

Seelandt, Julia C; Tschan, Franziska; Keller, Sandra; Beldi, Guido; Jenni, Nadja; Kurmann, Anita; Candinas, Daniel; Semmer, Norbert K

2014-11-01

To develop a behavioural observation method to simultaneously assess distractors and communication/teamwork during surgical procedures through direct, on-site observations; to establish the reliability of the method for long (>3 h) procedures. Observational categories for an event-based coding system were developed based on expert interviews, observations and a literature review. Using Cohen's κ and the intraclass correlation coefficient, interobserver agreement was assessed for 29 procedures. Agreement was calculated for the entire surgery, and for the 1st hour. In addition, interobserver agreement was assessed between two tired observers and between a tired and a non-tired observer after 3 h of surgery. The observational system has five codes for distractors (door openings, noise distractors, technical distractors, side conversations and interruptions), eight codes for communication/teamwork (case-relevant communication, teaching, leadership, problem solving, case-irrelevant communication, laughter, tension and communication with external visitors) and five contextual codes (incision, last stitch, personnel changes in the sterile team, location changes around the table and incidents). Based on 5-min intervals, Cohen's κ was good to excellent for distractors (0.74-0.98) and for communication/teamwork (0.70-1). Based on frequency counts, intraclass correlation coefficient was excellent for distractors (0.86-0.99) and good to excellent for communication/teamwork (0.45-0.99). After 3 h of surgery, Cohen's κ was 0.78-0.93 for distractors, and 0.79-1 for communication/teamwork. The observational method developed allows a single observer to simultaneously assess distractors and communication/teamwork. Even for long procedures, high interobserver agreement can be achieved. Data collected with this method allow for investigating separate or combined effects of distractions and communication/teamwork on surgical performance and patient outcomes. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Development of network-based multichannel neuromuscular electrical stimulation system for stroke rehabilitation.

PubMed

Qu, Hongen; Xie, Yongji; Liu, Xiaoxuan; He, Xin; Hao, Manzhao; Bao, Yong; Xie, Qing; Lan, Ning

2016-01-01

Neuromuscular electrical stimulation (NMES) is a promising assistive technology for stroke rehabilitation. Here we present the design and development of a multimuscle stimulation system as an emerging therapy for people with paretic stroke. A network-based multichannel NMES system was integrated based on dual bus architecture of communication and an H-bridge current regulator with a power booster. The structure of the system was a body area network embedded with multiple stimulators and a communication protocol of controlled area network to transmit muscle stimulation parameter information to individual stimulators. A graphical user interface was designed to allow clinicians to specify temporal patterns and muscle stimulation parameters. We completed and tested a prototype of the hardware and communication software modules of the multichannel NMES system. The prototype system was first verified in nondisabled subjects for safety, and then tested in subjects with stroke for feasibility with assisting multijoint movements. Results showed that synergistic stimulation of multiple muscles in subjects with stroke improved performance of multijoint movements with more natural velocity profiles at elbow and shoulder and reduced acromion excursion due to compensatory trunk rotation. The network-based NMES system may provide an innovative solution that allows more physiological activation of multiple muscles in multijoint task training for patients with stroke.

Risk Interfaces to Support Integrated Systems Analysis and Development

NASA Technical Reports Server (NTRS)

Mindock, Jennifer; Lumpkins, Sarah; Shelhamer, Mark; Anton, Wilma; Havenhill, Maria

2016-01-01

Objectives for systems analysis capability: Develop integrated understanding of how a complex human physiological-socio-technical mission system behaves in spaceflight. Why? Support development of integrated solutions that prevent unwanted outcomes (Implementable approaches to minimize mission resources(mass, power, crew time, etc.)); Support development of tools for autonomy (need for exploration) (Assess and maintain resilience -individuals, teams, integrated system). Output of this exercise: -Representation of interfaces based on Human System Risk Board (HSRB) Risk Summary information and simple status based on Human Research Roadmap; Consolidated HSRB information applied to support communication; Point-of-Departure for HRP Element planning; Ability to track and communicate status of collaborations. 4

Adjustable Parameter-Based Distributed Fault Estimation Observer Design for Multiagent Systems With Directed Graphs.

PubMed

Zhang, Ke; Jiang, Bin; Shi, Peng

2017-02-01

In this paper, a novel adjustable parameter (AP)-based distributed fault estimation observer (DFEO) is proposed for multiagent systems (MASs) with the directed communication topology. First, a relative output estimation error is defined based on the communication topology of MASs. Then a DFEO with AP is constructed with the purpose of improving the accuracy of fault estimation. Based on H ∞ and H 2 with pole placement, multiconstrained design is given to calculate the gain of DFEO. Finally, simulation results are presented to illustrate the feasibility and effectiveness of the proposed DFEO design with AP.

A comparison of communication using the Apple iPad and a picture-based system.

PubMed

Flores, Margaret; Musgrove, Kate; Renner, Scott; Hinton, Vanessa; Strozier, Shaunita; Franklin, Susan; Hil, Doris

2012-06-01

Augmentative and alternative communication (AAC) interventions have been shown to improve both communication and social skills in children and youth with autism spectrum disorders and other developmental disabilities. AAC applications have become available for personal devices such as cell phones, MP3 Players, and personal computer tablets. It is critical that these new forms of AAC are explored and evaluated. The purpose of this study was to investigate the utility of the Apple iPad™ as a communication device by comparing its use to a communication system using picture cards. Five elementary students with autism spectrum disorders and developmental disabilities who used a picture card system participated in the study. The results were mixed; communication behaviors either increased when using the iPad or remained the same as when using picture cards. The implications of these findings are discussed.

A wireless medical monitoring over a heterogeneous sensor network.

PubMed

Yuce, Mehmet R; Ng, Peng Choong; Lee, Chin K; Khan, Jamil Y; Liu, Wentai

2007-01-01

This paper presents a heterogeneous sensor network system that has the capability to monitor physiological parameters from multiple patient bodies by means of different communication standards. The system uses the recently opened medical band called MICS (Medical Implant Communication Service) between the sensor nodes and a remote central control unit (CCU) that behaves as a base station. The CCU communicates with another network standard (the internet or a mobile network) for a long distance data transfer. The proposed system offers mobility to patients and flexibility to medical staff to obtain patient's physiological data on demand basis via Internet. A prototype sensor network including hardware, firmware and software designs has been implemented and tested by incorporating temperature and pulse rate sensors on nodes. The developed system has been optimized for power consumption by having the nodes sleep when there is no communication via a bidirectional communication.

Constructing, Consuming, and Complicating the Human-Nature Binary: Communication Practices in Forest Environmental Education

ERIC Educational Resources Information Center

Dickinson, Elizabeth A.

2010-01-01

This project combines interdisciplinary conversations within the field of communication to examine environmental meaning systems and communication practices in the context of forest environmental education. Due to concerns over children's environmental alienation, there has been a continued push toward place-based environmental education. One such…

Skills in Clinical Communication: Are We Correctly Assessing Them at Undergraduate Level?

ERIC Educational Resources Information Center

Zamora Cervantes, Alberto; Carrión Ribas, Carme; Cordón Granados, Ferran; Galí Pla, Bibiana; Balló Peña, Elisabet; Quesada Sabate, Miquel; Grau Martin, Armand; Castro Guardiola, Antoni; Torrent Goñi, Silvia; Vargas Vila, Susanna; Vilert Garrofa, Esther; Subirats Bayego, Enric; Coll de Tuero, Gabriel; Muñoz Ortiz, Laura; Cerezo Goyeneche, Carlos; Torán Monserrat, Pere

2014-01-01

Traditional learning and assessment systems are overwhelmed when it comes to addressing the complex and multi-dimensional problems of clinical communication and professional practice. This paper shows results of a training program in clinical communication under Problem Based Learning (PBL) methodology and correlation between student…

The Unusual Suspects: Myths and Misconceptions Associated with PECS

ERIC Educational Resources Information Center

Bondy, Andy

2012-01-01

The Picture Exchange Communication System (PECS) is an alternative/augmentative communication protocol designed to help children and adults with autism and related disabilities to engage in functional communication. The protocol was developed over a number of years and was based on Skinner's analysis of verbal behavior. Publications about the…

Implementation of a Prototype Generalized Network Technology for Hospitals *

PubMed Central

Tolchin, S. G.; Stewart, R. L.; Kahn, S. A.; Bergan, E. S.; Gafke, G. P.; Simborg, D. W.; Whiting-O'Keefe, Q. E.; Chadwick, M. G.; McCue, G. E.

1981-01-01

A demonstration implementation of a distributed data processing hospital information system using an intelligent local area communications network (LACN) technology is described. This system is operational at the UCSF Medical Center and integrates four heterogeneous, stand-alone minicomputers. The applications systems are PID/Registration, Outpatient Pharmacy, Clinical Laboratory and Radiology/Medical Records. Functional autonomy of these systems has been maintained, and no operating system changes have been required. The LACN uses a fiber-optic communications medium and provides extensive communications protocol support within the network, based on the ISO/OSI Model. The architecture is reconfigurable and expandable. This paper describes system architectural issues, the applications environment and the local area network.

Implementation of the Vocera Communication System in a Quaternary Perioperative Environment.

PubMed

Friend, Tynan H; Jennings, Samantha J; Copenhaver, Martin S; Levine, Wilton C

2017-01-01

In the hospital, fast and efficient communication among clinicians and other employees is paramount to ensure optimal patient care, workflow efficiency, patient safety and patient comfort. The implementation of the wireless Vocera® Badge, a hands-free wearable device distributed to perioperative team members, has increased communication efficiency across the perioperative environment at Massachusetts General Hospital (MGH). This quality improvement project, based upon identical pre- and post-implementation surveys, used qualitative and quantitative analysis to determine if and how the Vocera system affected the timeliness of information flow, ease of communication, and operating room noise levels throughout the perioperative environment. Overall, the system increased the speed of information flow and eased communication between coworkers yet was perceived to have raised the overall noise level in and around the operating rooms (ORs). The perceived increase in noise was outweighed by the closed-loop communication between clinicians. Further education of the system's features in regard to speech recognition and privacy along with expected conversation protocol are necessary to ensure hassle-free communication for all staff.

A development framework for artificial intelligence based distributed operations support systems

NASA Technical Reports Server (NTRS)

Adler, Richard M.; Cottman, Bruce H.

1990-01-01

Advanced automation is required to reduce costly human operations support requirements for complex space-based and ground control systems. Existing knowledge based technologies have been used successfully to automate individual operations tasks. Considerably less progress has been made in integrating and coordinating multiple operations applications for unified intelligent support systems. To fill this gap, SOCIAL, a tool set for developing Distributed Artificial Intelligence (DAI) systems is being constructed. SOCIAL consists of three primary language based components defining: models of interprocess communication across heterogeneous platforms; models for interprocess coordination, concurrency control, and fault management; and for accessing heterogeneous information resources. DAI applications subsystems, either new or existing, will access these distributed services non-intrusively, via high-level message-based protocols. SOCIAL will reduce the complexity of distributed communications, control, and integration, enabling developers to concentrate on the design and functionality of the target DAI system itself.

Unmanned Aviation Systems Models of the Radio Communications Links: Study Results - Appendices Annex 2. Volume 1 and Volume 2

NASA Technical Reports Server (NTRS)

Birr, Richard B.; Spencer, Roy; Murray, Jennifer; Lash, Andrew

2013-01-01

This report describes the analysis of communications between the Control Station and an Unmanned Aircraft (UA) flying in the National Airspace System (NAS). This work is based on the RTCA SC-203 Operational Services and Environment Description (OSED). The OSED document seeks to characterize the highly different attributes of all UAs navigating the airspace and define their relationship to airspace users, air traffic services, and operating environments of the NAS. One goal of this report is to lead to the development of Minimum Aviation System Performance Standards for Control and Communications. This report takes the nine scenarios found in the OSED and analyzes the communication links.

Technology developments integrating a space network communications testbed

NASA Technical Reports Server (NTRS)

Kwong, Winston; Jennings, Esther; Clare, Loren; Leang, Dee

2006-01-01

As future manned and robotic space explorations missions involve more complex systems, it is essential to verify, validate, and optimize such systems through simulation and emulation in a low cost testbed environment. The goal of such a testbed is to perform detailed testing of advanced space and ground communications networks, technologies, and client applications that are essential for future space exploration missions. We describe the development of new technologies enhancing our Multi-mission Advanced Communications Hybrid Environment for Test and Evaluation (MACHETE) that enables its integration in a distributed space communications testbed. MACHETE combines orbital modeling, link analysis, and protocol and service modeling to quantify system performance based on comprehensive considerations of different aspects of space missions.

Developing Systems Engineering Skills Through NASA Summer Intern Project

NASA Technical Reports Server (NTRS)

Bhasin, Kul; Barritt, Brian; Golden, Bert; Knoblock, Eric; Matthews, Seth; Warner, Joe

2010-01-01

During the Formulation phases of the NASA Project Life Cycle, communication systems engineers are responsible for designing space communication links and analyzing their performance to ensure that the proposed communication architecture is capable of satisfying high-level mission requirements. Senior engineers with extensive experience in communications systems perform these activities. However, the increasing complexity of space systems coupled with the current shortage of communications systems engineers has led to an urgent need for expedited training of new systems engineers. A pilot program, in which college-bound high school and undergraduate students studying various engineering disciplines are immersed in NASA s systems engineering practices, was conceived out of this need. This rapid summerlong training approach is feasible because of the availability of advanced software and technology tools and the students inherent ability to operate such tools. During this pilot internship program, a team of college-level and recently-hired engineers configured and utilized various software applications in the design and analysis of communication links for a plausible lunar sortie mission. The approach taken was to first design the direct-to-Earth communication links for the lunar mission elements, then to design the links between lunar surface and lunar orbital elements. Based on the data obtained from these software applications, an integrated communication system design was realized and the students gained valuable systems engineering knowledge. This paper describes this approach to rapidly training college-bound high school and undergraduate engineering students from various disciplines in NASA s systems engineering practices and tools. A summary of the potential use of NASA s emerging systems engineering internship program in broader applications is also described.

Concept and implementation of the Globalstar mobile satellite system

NASA Technical Reports Server (NTRS)

Schindall, Joel

1995-01-01

Globalstar is a satellite-based mobile communications system which provides quality wireless communications (voice and/or data) anywhere in the world except the polar regions. The Globalstar system concept is based upon technological advancements in Low Earth Orbit (LEO) satellite technology and in cellular telephone technology, including the commercial application of Code Division Multiple Access (CDMA) technologies. The Globalstar system uses elements of CDMA and Frequency Division Multiple Access (FDMA), combined with satellite Multiple Beam Antenna (MBA) technology and advanced variable-rate vocoder technology to arrive at one of the most efficient modulation and multiple access systems ever proposed for a satellite communications system. The technology used in Globalstar includes the following techniques in obtaining high spectral efficiency and affordable cost per channel: (1) CDMA modulation with efficient power control; (2) high efficiency vocoder with voice activity factor; (3) spot beam antenna for increased gain and frequency reuse; (4) weighted satellite antenna gain for broad geographic coverage; (5) multisatellite user links (diversity) to enhance communications reliability; and (6) soft hand-off between beams and satellites. Initial launch is scheduled in 1997 and the system is scheduled to be operational in 1998. The Globalstar system utilizes frequencies in L-, S- and C-bands which have the potential to offer worldwide availability with authorization by the appropriate regulatory agencies.

A TinyOS-based wireless neural interface.

PubMed

Farshchi, Shahin; Mody, Istvan; Judy, Jack W

2004-01-01

The overlay of a neural interface upon a TinyOS-based sensing and communication platform is described. The system amplifies, digitally encodes, and transmits two EEG channels of neural signals from an un-tethered subject to a remote gateway, which routes the signals to a client PC. This work demonstrates the viability of the TinyOS-based sensor technology as a foundation for chronic remote biological monitoring applications, and thus provides an opportunity to create a system that can leverage from the frequent networking and communications advancements being made by the global TinyOS-development community.

Research on a Banknote Printing Wastewater Monitoring System based on Wireless Sensor Network

NASA Astrophysics Data System (ADS)

Li, B. B.; Yuan, Z. F.

2006-10-01

In this paper, a banknote printing wastewater monitoring system based on WSN is presented in line with the system demands and actual condition of the worksite for a banknote printing factory. In Physical Layer, the network node is a nRF9e5-centric embedded instrument, which can realize the multi-function such as data collecting, status monitoring, wireless data transmission and so on. Limited by the computing capability, memory capability, communicating energy and others factors, it is impossible for the node to get every detail information of the network, so the communication protocol on WSN couldn't be very complicated. The competitive-based MACA (Multiple Access with Collision Avoidance) Protocol is introduced in MAC, which can decide the communication process and working mode of the nodes, avoid the collision of data transmission, hidden and exposed station problem of nodes. On networks layer, the routing protocol in charge of the transmitting path of the data, the networks topology structure is arranged based on address assignation. Accompanied with some redundant nodes, the network performances stabile and expandable. The wastewater monitoring system is a tentative practice of WSN theory in engineering. Now, the system has passed test and proved efficiently.

A Measurement and Power Line Communication System Design for Renewable Smart Grids

NASA Astrophysics Data System (ADS)

Kabalci, E.; Kabalci, Y.

2013-10-01

The data communication over the electric power lines can be managed easily and economically since the grid connections are already spread around all over the world. This paper investigates the applicability of Power Line Communication (PLC) in an energy generation system that is based on photovoltaic (PV) panels with the modeling study in Matlab/Simulink. The Simulink model covers the designed PV panels, boost converter with Perturb and Observe (P&O) control algorithm, full bridge inverter, and the binary phase shift keying (BPSK) modem that is utilized to transfer the measured data over the power lines. This study proposes a novel method to use the electrical power lines not only for carrying the line voltage but also to transmit the measurements of the renewable energy generation plants. Hence, it is aimed at minimizing the additional monitoring costs such as SCADA, Ethernet-based or GSM based systems by using the proposed technique. Although this study is performed with solar power plants, the proposed model can be applied to other renewable generation systems. Consequently, the usage of the proposed technique instead of SCADA or Ethernet-based systems eliminates additional monitoring costs.

An E-Hospital Security Architecture

NASA Astrophysics Data System (ADS)

Tian, Fang; Adams, Carlisle

In this paper, we introduce how to use cryptography in network security and access control of an e-hospital. We first define the security goal of the e-hospital system, and then we analyze the current application system. Our idea is proposed on the system analysis and the related regulations of patients' privacy protection. The security of the whole application system is strengthened through layered security protection. Three security domains in the e-hospital system are defined according to their sensitivity level, and for each domain, we propose different security protections. We use identity based cryptography to establish secure communication channel in the backbone network and policy based cryptography to establish secure communication channel between end users and the backbone network. We also use policy based cryptography in the access control of the application system. We use a symmetric key cryptography to protect the real data in the database. The identity based and policy based cryptography are all based on elliptic curve cryptography—a public key cryptography.

Concept for a Satellite-Based Advanced Air Traffic Management System : Volume 2. System Functional Description and System Specification.

DOT National Transportation Integrated Search

1973-02-01

The volume provides a functional description and specification for the Satellite-Based Advanced Air Traffic Management System. The system description is presented in terms of the surveillance, navigation, and communications functions along with the a...

An observation tool to study air traffic control and flightdeck collaboration.

PubMed

Cox, Gemma; Sharples, Sarah; Stedmon, Alex; Wilson, John

2007-07-01

The complex systems of the flightdeck (FD) and the Air Traffic Control Centre (ATC) are characterised by numerous concurrently operating and interacting communication channels between people and between people and machines/computer systems. This paper describes work in support of investigating the impact of changes to technologies and responsibilities within this system with respect to human factors. It focuses primarily on the introduction of datalink (text-based communication rather than traditional radio communication) and the move towards freeflight (pilot-mediated air traffic control). Air traffic management investigations have outlined these specific changes as strategies to enable further increases in the volume of air traffic. A systems approach was taken and field studies were conducted. Small numbers of domain experts such as air traffic controllers (ATCOs) were involved in the field-based observations of how people interact with systems and each other. This paper summarises the overall research approach taken and then specifically reports on the field-based observations including the justification, development, and findings of the observation tool used. The observation tool examined information propagation through the air traffic control-flightdeck (ATC-FD) system, and resulted in models of possible information trajectories through the system.

The effects of scenario-based simulation course training on nurses' communication competence and self-efficacy: a randomized controlled trial.

PubMed

Hsu, Li-Ling; Chang, Wen-Hui; Hsieh, Suh-Ing

2015-01-01

Studies have shown that an underappreciation of the importance of person-centered communication and inappropriate communication training could result in unsatisfactory communication performance from nurses. There are a large number of studies about communication training for nurses, but not so many about communication training in early stages of nursing career. The purpose of this study is to compare the effect of a traditional course versus scenario-based simulation training on nurses' communication competency, communication self-efficacy, and communication performance in discharge planning Objective Structured Clinical Examination (OSCE). A randomized controlled trial was used with a pretest and two posttests. The experimental group underwent the scenario-based simulation course, whereas the control group received the traditional course. A convenience sample of 116 nurses with qualifications ranging from N0 level (novice nurses) to N2 level (competent nurses) in Taiwan's clinical nursing ladder system was recruited from a medical center in northern Taiwan. Analysis of covariance was used to determine between-subjects effects on communication competency and self-efficacy, whereas independent t test and Mann-Whitney U test were used to examine between-subjects effects on learner satisfaction and discharge planning communication performance. Paired t test was used to determine communication self-efficacy. In this study, the nurses and independent raters found scenario-based simulation training more effective than traditional communication course. However, standardized patients reported no significant difference in communication performance between the two groups of nurses. Despite that traditional classroom lectures and simulation-based communication training could both produce enhanced communication competency and self-efficacy among nurses, this study has established that the latter may be better than the former in terms of learner satisfaction and communication performance improvement. Therefore, introduction of simulation-based training to in-service nursing education could enhance nurses' communication performance in clinical practice. Copyright © 2015 Elsevier Inc. All rights reserved.

Laser Communication Demonstration System (LCDS) and future mobile satellite services

NASA Technical Reports Server (NTRS)

Chen, Chien-Chung; Wilhelm, Michael D.; Lesh, James R.

1995-01-01

The Laser Communications Demonstration System (LCDS) is a proposed in-orbit demonstration of high data rate laser communications technology conceived jointly by NASA and U.S. industry. The program objectives are to stimulate industry development and to demonstrate the readiness of high data rate optical communications in Earth orbit. For future global satellite communication systems using intersatellite links, laser communications technology can offer reduced mass and power requirements and higher channel bandwidths without regulatory constraints. As currently envisioned, LCDS will consist of one or two orbiting laser communications terminals capable of demonstrating high data rate (greater than 750Mbps) transmission in a dynamic space environment. Two study teams led by Motorola and Ball Aerospace are currently in the process of conducting a Phase A/B mission definition study of LCDS under contracts with JPL/NASA. The studies consist of future application survey, concept and requirements definition, and a point design of the laser communications flight demonstration. It is planned that a single demonstration system will be developed based on the study results. The Phase A/B study is expected to be completed by the coming June, and the current results of the study are presented in this paper.

Beam width and transmitter power adaptive to tracking system performance for free-space optical communication.

PubMed

Arnon, S; Rotman, S; Kopeika, N S

1997-08-20

The basic free-space optical communication system includes at least two satellites. To communicate between them, the transmitter satellite must track the beacon of the receiver satellite and point the information optical beam in its direction. Optical tracking and pointing systems for free space suffer during tracking from high-amplitude vibration because of background radiation from interstellar objects such as the Sun, Moon, Earth, and stars in the tracking field of view or the mechanical impact from satellite internal and external sources. The vibrations of beam pointing increase the bit error rate and jam communication between the two satellites. One way to overcome this problem is to increase the satellite receiver beacon power. However, this solution requires increased power consumption and weight, both of which are disadvantageous in satellite development. Considering these facts, we derive a mathematical model of a communication system that adapts optimally the transmitter beam width and the transmitted power to the tracking system performance. Based on this model, we investigate the performance of a communication system with discrete element optical phased array transmitter telescope gain. An example for a practical communication system between a Low Earth Orbit Satellite and a Geostationary Earth Orbit Satellite is presented. From the results of this research it can be seen that a four-element adaptive transmitter telescope is sufficient to compensate for vibration amplitude doubling. The benefits of the proposed model are less required transmitter power and improved communication system performance.

Overview of the LINCS architecture

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fletcher, J.G.; Watson, R.W.

1982-01-13

Computing at the Lawrence Livermore National Laboratory (LLNL) has evolved over the past 15 years with a computer network based resource sharing environment. The increasing use of low cost and high performance micro, mini and midi computers and commercially available local networking systems will accelerate this trend. Further, even the large scale computer systems, on which much of the LLNL scientific computing depends, are evolving into multiprocessor systems. It is our belief that the most cost effective use of this environment will depend on the development of application systems structured into cooperating concurrent program modules (processes) distributed appropriately over differentmore » nodes of the environment. A node is defined as one or more processors with a local (shared) high speed memory. Given the latter view, the environment can be characterized as consisting of: multiple nodes communicating over noisy channels with arbitrary delays and throughput, heterogenous base resources and information encodings, no single administration controlling all resources, distributed system state, and no uniform time base. The system design problem is - how to turn the heterogeneous base hardware/firmware/software resources of this environment into a coherent set of resources that facilitate development of cost effective, reliable, and human engineered applications. We believe the answer lies in developing a layered, communication oriented distributed system architecture; layered and modular to support ease of understanding, reconfiguration, extensibility, and hiding of implementation or nonessential local details; communication oriented because that is a central feature of the environment. The Livermore Interactive Network Communication System (LINCS) is a hierarchical architecture designed to meet the above needs. While having characteristics in common with other architectures, it differs in several respects.« less

Music recommendation system for biofied building considering multiple residents

NASA Astrophysics Data System (ADS)

Ito, Takahiro; Mita, Akira

2012-04-01

This research presents a music recommendation system based on multiple users' communication excitement and productivity. Evaluation is conducted on following two points. 1, Does songA recommended by the system improve the situation of dropped down communication excitement? 2, Does songB recommended by the system improve the situation of dropped down and productivity of collaborative work? The objective of this system is to recommend songs which shall improve the situation of dropped down communication excitement and productivity. Songs are characterized according to three aspects; familiarity, relaxing and BPM(Beat Per Minutes). Communication excitement is calculated from speech data obtained by an audio sensor. Productivity of collaborative brainstorming is manually calculated by the number of time-series key words during mind mapping. First experiment was music impression experiment to 118 students. Based on 1, average points of familiarity, relaxing and BPM 2, cronbach alpha factor, songA(high familiarity, high relaxing and high BPM song) and songB(high familiarity, high relaxing and low BPM) are selected. Exploratory experiment defined dropped down communication excitement and dropped down and productivity of collaborative work. Final experiment was conducted to 32 first meeting students divided into 8 groups. First 4 groups had mind mapping 1 while listening to songA, then had mind mapping 2 while listening songB. Following 4 groups had mind mapping 1 while listening to songB, then had mind mapping 2 while listening songA. Fianl experiment shows two results. Firstly, ratio of communication excitement between music listening section and whole brain storming is 1.27. Secondly, this system increases 69% of average productivity.

Optical communication in free space

NASA Technical Reports Server (NTRS)

Plotkin, H. H.; Mcavoy, N.; Fitzmaurice, M. W.

1974-01-01

Two classes of laser communication systems for handling very high data rates across inter-satellite distances are considered that provide for high antenna gains, wide modulation bandwidths, and optical receiver sensitivities. System design considerations are based upon the carbon dioxide laser modulation to accommodate digital or analog information, and the neodymium doped YAG laser pulse for digital modulation.

A Diagnostic Study of Computer Application of Structural Communication Grid

ERIC Educational Resources Information Center

Bahar, Mehmet; Aydin, Fatih; Karakirik, Erol

2009-01-01

In this article, Structural communication grid (SCG), an alternative measurement and evaluation technique, has been firstly summarised and the design, development and implementation of a computer based SCG system have been introduced. The system is then tested on a sample of 154 participants consisting of candidate students, science teachers and…

Potential markets for a satellite-based mobile communications system

NASA Technical Reports Server (NTRS)

Jamieson, W. M.; Peet, C. S.; Bengston, R. J.

1976-01-01

The objective of the study was to define the market needs for improved land mobile communications systems. Within the context of this objective, the following goals were set: (1) characterize the present mobile communications industry; (2) determine the market for an improved system for mobile communications; and (3) define the system requirements as seen from the potential customer's viewpoint. The scope of the study was defined by the following parameters: (1) markets were confined to U.S. and Canada; (2) range of operation generally exceeded 20 miles, but this was not restrictive; (3) the classes of potential users considered included all private sector users, and non-military public sector users; (4) the time span examined was 1975 to 1985; and (5) highly localized users were generally excluded - e.g., taxicabs, and local paging.

Specific factors influencing information system/information and communication technology sourcing strategies in healthcare facilities.

PubMed

Potančok, Martin; Voříšek, Jiří

2016-09-01

Healthcare facilities use a number of information system/information and communication technologies. Each healthcare facility faces a need to choose sourcing strategies most suitable to ensure provision of information system/information and communication technology services, processes and resources. Currently, it is possible to observe an expansion of sourcing possibilities in healthcare informatics, which creates new requirements for sourcing strategies. Thus, the aim of this article is to identify factors influencing information system/information and communication technology sourcing strategies in healthcare facilities. The identification was based on qualitative research, namely, a case study. This study provides a set of internal and external factors with their impact levels. The findings also show that not enough attention is paid to these factors during decision-making. © The Author(s) 2015.

Monitoring of physiological parameters from multiple patients using wireless sensor network.

PubMed

Yuce, Mehmet R; Ng, Peng Choong; Khan, Jamil Y

2008-10-01

This paper presents a wireless sensor network system that has the capability to monitor physiological parameters from multiple patient bodies. The system uses the Medical Implant Communication Service band between the sensor nodes and a remote central control unit (CCU) that behaves as a base station. The CCU communicates with another network standard (the internet or a mobile network) for a long distance data transfer. The proposed system offers mobility to patients and flexibility to medical staff to obtain patient's physiological data on demand basis via Internet. A prototype sensor network including hardware, firmware and software designs has been implemented and tested. The developed system has been optimized for power consumption by having the nodes sleep when there is no communication via a bidirectional communication.

The Interactive Media Package for Assessment of Communication and Critical Thinking (IMPACCT[c]): Testing a Programmatic Online Communication Competence Assessment System

ERIC Educational Resources Information Center

Spitzberg, Brian H.

2011-01-01

IMPACCT is an online survey covering over 40 self-report types of student communication competency, as well as a test of critical thinking based on cognitive problem-solving. The student nominates two peers who rate the student's interpersonal, computer-mediated, group and leadership, and public speaking communication competence. The student takes…

System on a chip with MPEG-4 capability

NASA Astrophysics Data System (ADS)

Yassa, Fathy; Schonfeld, Dan

2002-12-01

Current products supporting video communication applications rely on existing computer architectures. RISC processors have been used successfully in numerous applications over several decades. DSP processors have become ubiquitous in signal processing and communication applications. Real-time applications such as speech processing in cellular telephony rely extensively on the computational power of these processors. Video processors designed to implement the computationally intensive codec operations have also been used to address the high demands of video communication applications (e.g., cable set-top boxes and DVDs). This paper presents an overview of a system-on-chip (SOC) architecture used for real-time video in wireless communication applications. The SOC specifications answer to the system requirements imposed by the application environment. A CAM-based video processor is used to accelerate data intensive video compression tasks such as motion estimations and filtering. Other components are dedicated to system level data processing and audio processing. A rich set of I/Os allows the SOC to communicate with other system components such as baseband and memory subsystems.

MedRapid--medical community & business intelligence system.

PubMed

Finkeissen, E; Fuchs, H; Jakob, T; Wetter, T

2002-01-01

currently, it takes at least 6 months for researchers to communicate their results. This delay is caused (a) by partial lacks of machine support for both representation as well as communication and (b) by media breaks during the communication process. To make an integrated communication between researchers and practitioners possible, a general structure for medical content representation has been set up. The procedure for data entry and quality management has been generalized and implemented in a web-based authoring system. The MedRapid-system supports the medical experts in entering their knowledge into a database. Here, the level of detail is still below that of current medical guidelines representation. However, the symmetric structure for an area-wide medical knowledge representation is highly retrievable and thus can quickly be communicated into daily routine for the improvement of the treatment quality. In addition, other sources like journal articles and medical guidelines can be references within the MedRapid-system and thus be communicated into daily routine. The fundamental system for the representation of medical reference knowledge (from reference works/books) itself is not sufficient for the friction-less communication amongst medical staff. Rather, the process of (a) representing medical knowledge, (b) refereeing the represented knowledge, (c) communicating the represented knowledge, and (d) retrieving the represented knowledge has to be unified. MedRapid will soon support the whole process on one server system.

[Supervised administration of Alzheimer's patients using information communication technology].

PubMed

Noda, Yasuha; Sakata, Yoshifumi; Kubota, Masakazu; Uemura, Kengo; Kihara, Takeshi; Kimura, Toru; Ino, Masashi; Tsuji, Teruyuki; Hayashi, Michiyuki; Kinoshita, Ayae

2014-12-01

Drug adherence is central to the treatment of dementia, which might reduce compliance due to memory loss, particularly among home-based patients with dementia. In order to improve drug adherence, we suggest the efficient and effective supervised administration by use of information communication technology(ICT). ICT makes face-to-face real-time communication possible, and it also enables picture sharing. Therefore, it might be useful to apply ICT to controlling and supervising medication for patients with dementia to improve drug adherence. Accordingly, we enrolled patients who were supposed to take a newly prescribed anti-dementia patch containing the choline esterase inhibitor rivastigmine(Rivastach®)and investigated the effect of ICT-based intervention for drug adherence, emotional change, and cognitive change, utilizing Skype, a free communication software program. Scheduled Skype interventions increased drug adherence ratio, levels of subjective satisfaction, and instrumental activities of daily living(IADL). Furthermore, we can provide patients and their caregivers with a feeling of safety through regular bidirectional communication, as patients can easily consult medical staff regarding the adverse effects of newly prescribed drugs. Instead of frequent visits to their primary physicians, ICT-based communications can be used as a substitute for supervision of medication, given the availability of the telecommunication system. By directly connecting the medical institution to the home, we expect that this ICT-based system will expand into the geriatric care field, including the care of elderly individuals living alone.

Central projections of sensory systems involved in honey bee dance language communication.

PubMed

Brockmann, Axel; Robinson, Gene E

2007-01-01

Honey bee dance language is a unique and complex form of animal communication used to inform nest mates in the colony about the specific location of food sources or new nest sites. Five different sensory systems have been implicated in acquiring and communicating the information necessary for dance language communication. We present results from neuronal tracer studies identifying the central projections from four of the five. Sensory neurons of the dorsal rim area of the compound eyes, involved in acquiring sun-compass based information, project to the dorsal-most part of the medulla. Sensory neurons of the neck hair plates, required to transpose sun-compass based information to gravity-based information in the dark hive, project to the dorsal labial neuromere of the subesophageal ganglion. Sensory neurons from the antennal joint hair sensilla and the Johnston's organ, which perceive information on dance direction and distance from mechanostimuli generated by abdomen waggling and wing vibration, project to the deutocerebral dorsal lobe and the subesophageal ganglion, and the posterior protocerebrum, respectively. We found no 'dance-specific' projections relative to those previously described for drone and queen honey bees and other insect species that do not exhibit dance communication. We suggest that the evolution of dance language communication was likely based on the modification of central neural pathways associated with path integration, the capability to calculate distance, and directional information during flight. Copyright 2007 S. Karger AG, Basel.

Trellis-coded CPM for satellite-based mobile communications

NASA Technical Reports Server (NTRS)

Abrishamkar, Farrokh; Biglieri, Ezio

1988-01-01

Digital transmission for satellite-based land mobile communications is discussed. To satisfy the power and bandwidth limitations imposed on such systems, a combination of trellis coding and continuous-phase modulated signals are considered. Some schemes based on this idea are presented, and their performance is analyzed by computer simulation. The results obtained show that a scheme based on directional detection and Viterbi decoding appears promising for practical applications.

Cooperating Expert Systems For Space Station Power Distribution Management

NASA Astrophysics Data System (ADS)

Nguyen, T. A.; Chiou, W. C.

1987-02-01

In a complex system such as the manned Space Station, it is deem necessary that many expert systems must perform tasks in a concurrent and cooperative manner. An important question arise is: what cooperative-task-performing models are appropriate for multiple expert systems to jointly perform tasks. The solution to this question will provide a crucial automation design criteria for the Space Station complex systems architecture. Based on a client/server model for performing tasks, we have developed a system that acts as a front-end to support loosely-coupled communications between expert systems running on multiple Symbolics machines. As an example, we use two ART*-based expert systems to demonstrate the concept of parallel symbolic manipulation for power distribution management and dynamic load planner/scheduler in the simulated Space Station environment. This on-going work will also explore other cooperative-task-performing models as alternatives which can evaluate inter and intra expert system communication mechanisms. It will be served as a testbed and a bench-marking tool for other Space Station expert subsystem communication and information exchange.

REACTOR - a Concept for establishing a System-of-Systems

NASA Astrophysics Data System (ADS)

Haener, Rainer; Hammitzsch, Martin; Wächter, Joachim

2014-05-01

REACTOR is a working title for activities implementing reliable, emergent, adaptive, and concurrent collaboration on the basis of transactional object repositories. It aims at establishing federations of autonomous yet interoperable systems (Systems-of-Systems), which are able to expose emergent behaviour. Following the principles of event-driven service-oriented architectures (SOA 2.0), REACTOR enables adaptive re-organisation by dynamic delegation of responsibilities and novel yet coherent monitoring strategies by combining information from different domains. Thus it allows collaborative decision-processes across system, discipline, and administrative boundaries. Interoperability is based on two approaches that implement interconnection and communication between existing heterogeneous infrastructures and information systems: Coordinated (orchestration-based) communication and publish/subscribe (choreography-based) communication. Choreography-based communication ensures the autonomy of the participating systems to the highest possible degree but requires the implementation of adapters, which provide functional access to information (publishing/consuming events) via a Message Oriented Middleware (MOM). Any interconnection of the systems (composition of service and message cascades) is established on the basis of global conversations that are enacted by choreographies specifying the expected behaviour of the participating systems with respect to agreed Service Level Agreements (SLA) required by e.g. national authorities. The specification of conversations, maintained in commonly available repositories also enables the utilisation of systems for purposes (evolving) other than initially intended. Orchestration-based communication additionally requires a central component that controls the information transfer via service requests or event processing and also takes responsibility of managing business processes. Commonly available transactional object repositories are well suited to establish brokers, which mediate metadata and semantic information about the resources of all involved systems. This concept has been developed within the project Collaborative, Complex, and Critical Decision-Support in Evolving Crises (TRIDEC) on the basis of semantic registries describing all facets of events and services utilisable for crisis management systems. The implementation utilises an operative infrastructure including an Enterprise Service Bus (ESB), adapters to proprietary sensor systems, a workflow engine, and a broker-based MOM. It also applies current technologies like actor-based frameworks for highly concurrent, distributed, and fault tolerant event-driven applications. Therefore REACTOR implementations are well suited to be hosted in a cloud that provides Infrastructure as a Service (IaaS). To provide low entry barriers for legacy and future systems, REACTOR adapts the principles of Design by Contract (DbC) as well as standardised and common information models like the Sensor Web Enablement (SWE) or the JavaScript Object Notation for geographic features (GeoJSON). REACTOR has been applied exemplarily within two different scenarios, Natural Crisis Management and Industrial Subsurface Development.

PAPR reduction based on tone reservation scheme for DCO-OFDM indoor visible light communications.

PubMed

Bai, Jurong; Li, Yong; Yi, Yang; Cheng, Wei; Du, Huimin

2017-10-02

High peak-to-average power ratio (PAPR) leads to out-of-band power and in-band distortion in the direct current-biased optical orthogonal frequency division multiplexing (DCO-OFDM) systems. In order to effectively reduce the PAPR with faster convergence and lower complexity, this paper proposes a tone reservation based scheme, which is the combination of the signal-to-clipping noise ratio (SCR) procedure and the least squares approximation (LSA) procedure. In the proposed scheme, the transmitter of the DCO-OFDM indoor visible light communication (VLC) system is designed to transform the PAPR reduced signal into real-valued positive OFDM signal without doubling the transmission bandwidth. Moreover, the communication distance and the light emitting diode (LED) irradiance angle are taking into consideration in the evaluation of the system bit error rate (BER). The PAPR reduction efficiency of the proposed scheme is remarkable for DCO-OFDM indoor VLC systems.

Realization of Real-Time Clinical Data Integration Using Advanced Database Technology

PubMed Central

Yoo, Sooyoung; Kim, Boyoung; Park, Heekyong; Choi, Jinwook; Chun, Jonghoon

2003-01-01

As information & communication technologies have advanced, interest in mobile health care systems has grown. In order to obtain information seamlessly from distributed and fragmented clinical data from heterogeneous institutions, we need solutions that integrate data. In this article, we introduce a method for information integration based on real-time message communication using trigger and advanced database technologies. Messages were devised to conform to HL7, a standard for electronic data exchange in healthcare environments. The HL7 based system provides us with an integrated environment in which we are able to manage the complexities of medical data. We developed this message communication interface to generate and parse HL7 messages automatically from the database point of view. We discuss how easily real time data exchange is performed in the clinical information system, given the requirement for minimum loading of the database system. PMID:14728271

Modeling convection-diffusion-reaction systems for microfluidic molecular communications with surface-based receivers in Internet of Bio-Nano Things

PubMed Central

Akan, Ozgur B.

2018-01-01

We consider a microfluidic molecular communication (MC) system, where the concentration-encoded molecular messages are transported via fluid flow-induced convection and diffusion, and detected by a surface-based MC receiver with ligand receptors placed at the bottom of the microfluidic channel. The overall system is a convection-diffusion-reaction system that can only be solved by numerical methods, e.g., finite element analysis (FEA). However, analytical models are key for the information and communication technology (ICT), as they enable an optimisation framework to develop advanced communication techniques, such as optimum detection methods and reliable transmission schemes. In this direction, we develop an analytical model to approximate the expected time course of bound receptor concentration, i.e., the received signal used to decode the transmitted messages. The model obviates the need for computationally expensive numerical methods by capturing the nonlinearities caused by laminar flow resulting in parabolic velocity profile, and finite number of ligand receptors leading to receiver saturation. The model also captures the effects of reactive surface depletion layer resulting from the mass transport limitations and moving reaction boundary originated from the passage of finite-duration molecular concentration pulse over the receiver surface. Based on the proposed model, we derive closed form analytical expressions that approximate the received pulse width, pulse delay and pulse amplitude, which can be used to optimize the system from an ICT perspective. We evaluate the accuracy of the proposed model by comparing model-based analytical results to the numerical results obtained by solving the exact system model with COMSOL Multiphysics. PMID:29415019

Modeling convection-diffusion-reaction systems for microfluidic molecular communications with surface-based receivers in Internet of Bio-Nano Things.

PubMed

Kuscu, Murat; Akan, Ozgur B

2018-01-01

We consider a microfluidic molecular communication (MC) system, where the concentration-encoded molecular messages are transported via fluid flow-induced convection and diffusion, and detected by a surface-based MC receiver with ligand receptors placed at the bottom of the microfluidic channel. The overall system is a convection-diffusion-reaction system that can only be solved by numerical methods, e.g., finite element analysis (FEA). However, analytical models are key for the information and communication technology (ICT), as they enable an optimisation framework to develop advanced communication techniques, such as optimum detection methods and reliable transmission schemes. In this direction, we develop an analytical model to approximate the expected time course of bound receptor concentration, i.e., the received signal used to decode the transmitted messages. The model obviates the need for computationally expensive numerical methods by capturing the nonlinearities caused by laminar flow resulting in parabolic velocity profile, and finite number of ligand receptors leading to receiver saturation. The model also captures the effects of reactive surface depletion layer resulting from the mass transport limitations and moving reaction boundary originated from the passage of finite-duration molecular concentration pulse over the receiver surface. Based on the proposed model, we derive closed form analytical expressions that approximate the received pulse width, pulse delay and pulse amplitude, which can be used to optimize the system from an ICT perspective. We evaluate the accuracy of the proposed model by comparing model-based analytical results to the numerical results obtained by solving the exact system model with COMSOL Multiphysics.

Another Way To View Child Development: An Interactive Approach to the Integration of the Sensorimotor System, Communication and Temperament. Project Ta-kos.

ERIC Educational Resources Information Center

Yoches, Betty; Luera, Margarita

The purpose of this training manual is to assist parents and professionals in understanding how a child's temperament, sensorimotor system, and communication system support each other in helping the child develop a solid foundation for normal growth and development. Training is based on the premise that awareness of the interaction and integration…

Performance analysis of Integrated Communication and Control System networks

NASA Technical Reports Server (NTRS)

Halevi, Y.; Ray, A.

1990-01-01

This paper presents statistical analysis of delays in Integrated Communication and Control System (ICCS) networks that are based on asynchronous time-division multiplexing. The models are obtained in closed form for analyzing control systems with randomly varying delays. The results of this research are applicable to ICCS design for complex dynamical processes like advanced aircraft and spacecraft, autonomous manufacturing plants, and chemical and processing plants.

Methods to prefetch comparison images in image management and communication system

NASA Astrophysics Data System (ADS)

Levin, Kenneth; Fielding, Robert

1990-08-01

A high-level description of a system to pre-fetch comparison radiographs in an Image Management and Communication System (IMAC) is presented. This rule based system estimates the relevance of previous examinations for comparison to the current examination arid uses this determination to pre-fetch comparison studies. A machine learning module should allow the system to improve its skill in pre-fetching examinations for each individual radiologist. This system could be tailored to fit the desires of individual radiologists.

Web-Based Cancer Communication and Decision Making Systems: Connecting Patients, Caregivers, and Clinicians for Improved Health Outcomes

PubMed Central

DuBenske, Lori L.; Gustafson, David H.; Shaw, Bret R.; Cleary, James F.

2011-01-01

Over the cancer disease trajectory, from diagnosis and treatment to remission or end of life, patients and their families face difficult decisions. The provision of information and support when most relevant can optimize cancer decision making and coping. An interactive health communication system (IHCS) offers the potential to bridge the communication gaps that occur among patients, family, and clinicians and to empower each to actively engage in cancer care and shared decision making. This is a report of the authors' experience (with a discussion of relevant literature) in developing and testing a Web-based IHCS—the Comprehensive Health Enhancement Support System (CHESS)—for patients with advanced lung cancer and their family caregivers. CHESS provides information, communication, and coaching resources as well as a symptom tracking system that reports health status to the clinical team. Development of an IHCS includes a needs assessment of the target audience and applied theory informed by continued stakeholder involvement in early testing. Critical issues of IHCS implementation include 1) need for interventions that accommodate a variety of format preferences and technology comfort ranges; 2) IHCS user training, 3) clinician investment in IHCS promotion, and 4) IHCS integration with existing medical systems. In creating such comprehensive systems, development strategies need to be grounded in population needs with appropriate use of technology that serves the target users, including the patient/family, clinical team, and health care organization. Implementation strategies should address timing, personnel, and environmental factors to facilitate continued use and benefit from IHCS. An interactive health communication system (IHCS) offers one platform for providing the information, communication, and coaching resources that cancer patients and their families need to understand the disease, find support, and develop decision-making and coping skills. One such IHCS—the Comprehensive Health Enhancement Support System (CHESS)—has evolved over the past 20 years. Based on our recent experience creating and testing a new version of CHESS—“Coping with Lung Cancer: A Network of Support”—this article outlines the issues faced in developing and implementing such a system within the cancer context. PMID:21041539

The synchronisation of fractional-order hyperchaos compound system

NASA Astrophysics Data System (ADS)

Noghredani, Naeimadeen; Riahi, Aminreza; Pariz, Naser; Karimpour, Ali

2018-02-01

This paper presents a new compound synchronisation scheme among four hyperchaotic memristor system with incommensurate fractional-order derivatives. First a new controller was designed based on adaptive technique to minimise the errors and guarantee compound synchronisation of four fractional-order memristor chaotic systems. According to the suitability of compound synchronisation as a reliable solution for secure communication, we then examined the application of the proposed adaptive compound synchronisation scheme in the presence of noise for secure communication. In addition, the unpredictability and complexity of the drive systems enhance the security of secure communication. The corresponding theoretical analysis and results of simulation validated the effectiveness of the proposed synchronisation scheme using MATLAB.

Neural Insights into the Relation between Language and Communication

PubMed Central

Willems, Roel M.; Varley, Rosemary

2010-01-01

The human capacity to communicate has been hypothesized to be causally dependent upon language. Intuitively this seems plausible since most communication relies on language. Moreover, intention recognition abilities (as a necessary prerequisite for communication) and language development seem to co-develop. Here we review evidence from neuroimaging as well as from neuropsychology to evaluate the relationship between communicative and linguistic abilities. Our review indicates that communicative abilities are best considered as neurally distinct from language abilities. This conclusion is based upon evidence showing that humans rely on different cortical systems when designing a communicative message for someone else as compared to when performing core linguistic tasks, as well as upon observations of individuals with severe language loss after extensive lesions to the language system, who are still able to perform tasks involving intention understanding. PMID:21151364

Design and application of the emergency response mobile phone-based information system for infectious disease reporting in the Wenchuan earthquake zone.

PubMed

Ma, Jiaqi; Zhou, Maigeng; Li, Yanfei; Guo, Yan; Su, Xuemei; Qi, Xiaopeng; Ge, Hui

2009-05-01

To describe the design and application of an emergency response mobile phone-based information system for infectious disease reporting. Software engineering and business modeling were used to design and develop the emergency response mobile phone-based information system for infectious disease reporting. Seven days after the initiation of the reporting system, the reporting rate in the earthquake zone reached the level of the same period in 2007, using the mobile phone-based information system. Surveillance of the weekly report on morbidity in the earthquake zone after the initiation of the mobile phone reporting system showed the same trend as the previous three years. The emergency response mobile phone-based information system for infectious disease reporting was an effective solution to transmit urgently needed reports and manage communicable disease surveillance information. This assured the consistency of disease surveillance and facilitated sensitive, accurate, and timely disease surveillance. It is an important backup for the internet-based direct reporting system for communicable disease. © 2009 Blackwell Publishing Asia Pty Ltd and Chinese Cochrane Center, West China Hospital of Sichuan University.

Design of a Physiology-Sensitive VR-Based Social Communication Platform for Children With Autism.

PubMed

Kuriakose, Selvia; Lahiri, Uttama

2017-08-01

Individuals with autism are often characterized by impairments in communication, reciprocal social interaction and explicit expression of their affective states. In conventional techniques, a therapist adjusts the intervention paradigm by monitoring the affective state e.g., anxiety of these individuals for effective floor-time-therapy. Conventional techniques, though powerful, are observation-based and face resource limitations. Technology-assisted systems can provide a quantitative, individualized rehabilitation platform. Presently-available systems are designed primarily to chain learning via aspects of one's performance alone restricting individualization. Specifically, these systems are not sensitive to one's anxiety. Our presented work seeks to bridge this gap by developing a novel VR-based interactive system with Anxiety-Sensitive adaptive technology. Specifically, such a system is capable of objectively identifying and quantifying one's anxiety level from real-time biomarkers, along with performance metrics. In turn it can adaptively respond in an individualized manner to foster improved social communication skills. In our present research, we have used Virtual Reality (VR) to design a proof-of-concept application that exposes participants to social tasks of varying challenges. Results of a preliminary usability study indicate the potential of our VR-based Anxiety-Sensitive system to foster improved task performance, thereby serving as a potent complementary tool in the hands of therapist.

Airport Surface Network Architecture Definition

NASA Technical Reports Server (NTRS)

Nguyen, Thanh C.; Eddy, Wesley M.; Bretmersky, Steven C.; Lawas-Grodek, Fran; Ellis, Brenda L.

2006-01-01

Currently, airport surface communications are fragmented across multiple types of systems. These communication systems for airport operations at most airports today are based dedicated and separate architectures that cannot support system-wide interoperability and information sharing. The requirements placed upon the Communications, Navigation, and Surveillance (CNS) systems in airports are rapidly growing and integration is urgently needed if the future vision of the National Airspace System (NAS) and the Next Generation Air Transportation System (NGATS) 2025 concept are to be realized. To address this and other problems such as airport surface congestion, the Space Based Technologies Project s Surface ICNS Network Architecture team at NASA Glenn Research Center has assessed airport surface communications requirements, analyzed existing and future surface applications, and defined a set of architecture functions that will help design a scalable, reliable and flexible surface network architecture to meet the current and future needs of airport operations. This paper describes the systems approach or methodology to networking that was employed to assess airport surface communications requirements, analyze applications, and to define the surface network architecture functions as the building blocks or components of the network. The systems approach used for defining these functions is relatively new to networking. It is viewing the surface network, along with its environment (everything that the surface network interacts with or impacts), as a system. Associated with this system are sets of services that are offered by the network to the rest of the system. Therefore, the surface network is considered as part of the larger system (such as the NAS), with interactions and dependencies between the surface network and its users, applications, and devices. The surface network architecture includes components such as addressing/routing, network management, network performance and security.

Effects of partitioning and scheduling sparse matrix factorization on communication and load balance

NASA Technical Reports Server (NTRS)

Venugopal, Sesh; Naik, Vijay K.

1991-01-01

A block based, automatic partitioning and scheduling methodology is presented for sparse matrix factorization on distributed memory systems. Using experimental results, this technique is analyzed for communication and load imbalance overhead. To study the performance effects, these overheads were compared with those obtained from a straightforward 'wrap mapped' column assignment scheme. All experimental results were obtained using test sparse matrices from the Harwell-Boeing data set. The results show that there is a communication and load balance tradeoff. The block based method results in lower communication cost whereas the wrap mapped scheme gives better load balance.

Prototype development and implementation of picture archiving and communications systems based on ISO-OSI standard

NASA Astrophysics Data System (ADS)

Martinez, Ralph; Nam, Jiseung

1992-07-01

Picture Archiving and Communication Systems (PACS) is an integration of digital image formation in a hospital, which encompasses various imaging equipment, image viewing workstations, image databases, and a high speed network. The integration requires a standardization of communication protocols to connect devices from different vendors. The American College of Radiology and the National Electrical Manufacturers Association (ACR- NEMA) standard Version 2.0 provides a point-to-point hardware interface, a set of software commands, and a consistent set of data formats for PACS. But, it is inadequate for PACS networking environments, because of its point-to-point nature and its inflexibility to allow other services and protocols in the future. Based on previous experience of PACS developments in The University of Arizona, a new communication protocol for PACS networks and an approach were proposed to ACR-NEMA Working Group VI. The defined PACS protocol is intended to facilitate the development of PACS''s capable of interfacing with other hospital information systems. Also, it is intended to allow the creation of diagnostic information data bases which can be interrogated by a variety of distributed devices. A particularly important goal is to support communications in a multivendor environment. The new protocol specifications are defined primarily as a combination of the International Organization for Standardization/Open Systems Interconnection (ISO/OSI), TCP/IP protocols, and the data format portion of ACR-NEMA standard. This paper addresses the specification and implementation of the ISO-based protocol into a PACS prototype. The protocol specification, which covers Presentation, Session, Transport, and Network layers, is summarized briefly. The protocol implementation is discussed based on our implementation efforts in the UNIX Operating System Environment. At the same time, results of performance comparison between the ISO and TCP/IP implementations are presented to demonstrate the implementation of defined protocol. The testing of performance analysis is done by prototyping PACS on available platforms, which are Micro VAX II, DECstation and SUN Workstation.

Secure Network-Centric Aviation Communication (SNAC)

NASA Technical Reports Server (NTRS)

Nelson, Paul H.; Muha, Mark A.; Sheehe, Charles J.

2017-01-01

The existing National Airspace System (NAS) communications capabilities are largely unsecured, are not designed for efficient use of spectrum and collectively are not capable of servicing the future needs of the NAS with the inclusion of new operators in Unmanned Aviation Systems (UAS) or On Demand Mobility (ODM). SNAC will provide a ubiquitous secure, network-based communications architecture that will provide new service capabilities and allow for the migration of current communications to SNAC over time. The necessary change in communication technologies to digital domains will allow for the adoption of security mechanisms, sharing of link technologies, large increase in spectrum utilization, new forms of resilience and redundancy and the possibly of spectrum reuse. SNAC consists of a long term open architectural approach with increasingly capable designs used to steer research and development and enable operating capabilities that run in parallel with current NAS systems.

Development and Validation of Performance Assessment Tools for Interprofessional Communication and Teamwork (PACT)

ERIC Educational Resources Information Center

Chiu, Chia-Ju

2014-01-01

Background: Medical errors caused by breakdowns in teamwork and interprofessional communication contribute to many deaths in the United States each year. Team Strategies and Tools to Enhance Performance and Patient Safety (TeamSTEPPS®) is an evidence-based teamwork system developed to improve communication and teamwork skills among health care…

Translating Face-to-Face Experiential Learning to Video for a Web-Based Communication Program

ERIC Educational Resources Information Center

Nelles, Laura Jayne; Smith, Cathy M.; Lax, Leila R.; Russell, Lynn

2011-01-01

The cultural, legal and ethical aspects of medical practice in Canada can be problematic for International Medical Graduates (IMGs) to access and learn. The professional behaviours that depend on effective communication often challenge IMGs as they attempt to enter the Canadian medical system. The Communication and Cultural Competence Program…

The transmission link of CAPS navigation and communication system

NASA Astrophysics Data System (ADS)

Cui, Junxia; Shi, Huli; Chen, Jibin; Pei, Jun

2009-03-01

The Chinese Area Positioning System (CAPS) is based on communication satellites with integrated capability, which is different from the Global Positioning System (GPS), the International Maritime Satellite Organization (Inmarsat) and so on. CAPS works at C-band, and its navigation information is not directly generated from the satellite, but from the master control station on the ground and transmitted to users via the satellite. The slightly inclined geostationary-satellite orbit (SIGSO) satellites are adopted in CAPS. All of these increase the difficulty in the design of the system and terminals. In this paper, the authors study the CAPS configuration parameters of the navigation master control station, information transmission capability, and the selection of the antenna aperture of the communication center station, as well as the impact of satellite parameters on the whole communication system from the perspective of the transmission link budget. The conclusion of availability of the CAPS navigation system is achieved. The results show that the CAPS inbound communication system forms a new low-data-rate satellite communication system, which can accommodate mass communication terminals with the transmission rate of no more than 1 kbps for every terminal. The communication center station should be configured with a large-aperture antenna (about 10-15 m); spread spectrum communication technology should be used with the spreading gain as high as about 40 dB; reduction of the satellite transponder gain attenuation is beneficial to improving the signal-to-noise ratio of the system, with the attenuation value of 0 or 2 dB as the best choice. The fact that the CAPS navigation system has been checked and accepted by the experts and the operation is stable till now clarifies the rationality of the analysis results. The fact that a variety of experiments and applications of the satellite communication system designed according to the findings in this paper have been successfully carried out confirms the correctness of the study results.

Low latency messages on distributed memory multiprocessors

NASA Technical Reports Server (NTRS)

Rosing, Matthew; Saltz, Joel

1993-01-01

Many of the issues in developing an efficient interface for communication on distributed memory machines are described and a portable interface is proposed. Although the hardware component of message latency is less than one microsecond on many distributed memory machines, the software latency associated with sending and receiving typed messages is on the order of 50 microseconds. The reason for this imbalance is that the software interface does not match the hardware. By changing the interface to match the hardware more closely, applications with fine grained communication can be put on these machines. Based on several tests that were run on the iPSC/860, an interface that will better match current distributed memory machines is proposed. The model used in the proposed interface consists of a computation processor and a communication processor on each node. Communication between these processors and other nodes in the system is done through a buffered network. Information that is transmitted is either data or procedures to be executed on the remote processor. The dual processor system is better suited for efficiently handling asynchronous communications compared to a single processor system. The ability to send data or procedure is very flexible for minimizing message latency, based on the type of communication being performed. The test performed and the proposed interface are described.

SpaceWire- Based Control System Architecture for the Lightweight Advanced Robotic Arm Demonstrator [LARAD

NASA Astrophysics Data System (ADS)

Rucinski, Marek; Coates, Adam; Montano, Giuseppe; Allouis, Elie; Jameux, David

2015-09-01

The Lightweight Advanced Robotic Arm Demonstrator (LARAD) is a state-of-the-art, two-meter long robotic arm for planetary surface exploration currently being developed by a UK consortium led by Airbus Defence and Space Ltd under contract to the UK Space Agency (CREST-2 programme). LARAD has a modular design, which allows for experimentation with different electronics and control software. The control system architecture includes the on-board computer, control software and firmware, and the communication infrastructure (e.g. data links, switches) connecting on-board computer(s), sensors, actuators and the end-effector. The purpose of the control system is to operate the arm according to pre-defined performance requirements, monitoring its behaviour in real-time and performing safing/recovery actions in case of faults. This paper reports on the results of a recent study about the feasibility of the development and integration of a novel control system architecture for LARAD fully based on the SpaceWire protocol. The current control system architecture is based on the combination of two communication protocols, Ethernet and CAN. The new SpaceWire-based control system will allow for improved monitoring and telecommanding performance thanks to higher communication data rate, allowing for the adoption of advanced control schemes, potentially based on multiple vision sensors, and for the handling of sophisticated end-effectors that require fine control, such as science payloads or robotic hands.

Design of compact off-axis four-mirror anastigmatic system for space communications

NASA Astrophysics Data System (ADS)

Zhao, Fa-cai; Sun, Quan-she; Chen, Kun-feng; Zhu, Xing-bang; Wang, Shao-shui; Wang, Guo-quan; Zheng, Xiang-liang

2013-08-01

The deployment of advanced hyperspectral imaging and other Earth sensing instruments onboard Earth observing satellites is driving the demand for high-data rate communications. Space laser communications technology offers the potential for significantly increasing in data return capability from space to Earth. Compared to the current state of the art radio frequency communications links, lasercom links operate at much higher carrier frequencies. The use of higher carrier frequencies implies a much smaller diffraction loss, which in turn, results in a much higher efficiency in delivering the signal energy. Optical communications meet the required data rates with small, low-mass, and low-power communications packages. The communications optical system assembly typically consists of a front aperture, reflection or refraction type telescope, with or without a solar rejection filter, aft optics, fine-pointing mirrors, and array detectors. Optical system used in space laser communications usually has long focal length, large aperture compared with common optical systems. So the reflective optical system is widely used. An unobstructed four-mirror anastigmatic telescope system was proposed, which was modified based on the theory about geometry optics of common-axis three-mirror systems. Intermediate image was between secondary and tertiary mirror. In order to fold the optical path, four-mirror was designed by adding the plane reflective mirror at intermediate image. The design was analyzed, then a system with effective aperture of 200mm and field of view of 1.0°x1.0° was designed, total length and magnification are 700mm and 20, respectively. The system has advantages of large magnification, relative short physical size and loose manufacturing tolerances.

Iridium: Global OTH data communications for high altitude scientific ballooning

NASA Astrophysics Data System (ADS)

Denney, A.

While the scientific community is no stranger to embracing commercially available technologies, the growth and availability of truly affordable cutting edge technologies is opening the door to an entirely new means of global communications. For many years high altitude ballooning has provided science an alternative to costly satellite based experimental platforms. As with any project, evolution becomes an integral part of development. Specifically in the NSBF ballooning program, where flight durations have evolved from the earlier days of hours to several weeks and plans are underway to provide missions up to 100 days. Addressing increased flight durations, the harsh operational environment, along with cumbersome and outdated systems used on existing systems, such as the balloon vehicles Support Instrumentation Package (SIP) and ground-based systems, a new Over-The-Horizon (OTH) communications medium is sought. Current OTH equipment planning to be phased-out include: HF commanding systems, ARGOS PTT telemetry downlinks and INMARSAT data terminals. Other aspects up for review in addition to the SIP to utilize this communications medium include pathfinder balloon platforms - thereby, adding commanding abilities and increased data rates, plus providing a package for ultra-small experiments to ride aloft. Existing communication systems employed by the National Scientific Balloon Facility ballooning program have been limited not only by increased cost, slow data rates and "special government use only" services such as TDRSS (Tracking and Data Relay Satellite System), but have had to make special provisions to geographical flight location. Development of the Support Instrumentation Packages whether LDB (Long Duration Balloon), ULDB (Ultra Long Duration Balloon) or conventional ballooning have been plagued by non-standard systems configurations requiring additional support equipment for different regions and missions along with a myriad of backup for redundancy. Several beneficial points provided by the Iridium platform include pure global accessibility (as well as polar), cost effectiveness because it is available as a COTS (Commercially Off The Shelf) technology, reliability in that the equipment must operate in extreme conditions (near space), integration and development time into current systems must be minimized. As a bonus Motorola and NAL Research Corporation are developing SBD (Short Burst Data) into the Iridium network. This may lead the way to a global IP (Internet Protocol) node based ballooning platform. The Iridium satellite data modems employ the Iridium Low-Earth Orbit (LEO) satellite network. The scope of this paper is to introduce an OTH communications alternative, albeit not necessarily a primary one, to existing ballooning platforms using COTS based emerging technologies. Design aspects, characteristics, actual flight testing statistics, principles of the Iridium modems and communication paths are described including payload and support instrumentation interfacing. Not limited to high altitude ballooning, the Iridium communications platform opens a new era in remote commanding and data retrieval.

Interoperative fundus image and report sharing in compliance with integrating the healthcare enterprise conformance and web access to digital imaging and communication in medicine persistent object protocol.

PubMed

Wu, Hui-Qun; Lv, Zheng-Min; Geng, Xing-Yun; Jiang, Kui; Tang, Le-Min; Zhou, Guo-Min; Dong, Jian-Cheng

2013-01-01

To address issues in interoperability between different fundus image systems, we proposed a web eye-picture archiving and communication system (PACS) framework in conformance with digital imaging and communication in medicine (DICOM) and health level 7 (HL7) protocol to realize fundus images and reports sharing and communication through internet. Firstly, a telemedicine-based eye care work flow was established based on integrating the healthcare enterprise (IHE) Eye Care technical framework. Then, a browser/server architecture eye-PACS system was established in conformance with the web access to DICOM persistent object (WADO) protocol, which contains three tiers. In any client system installed with web browser, clinicians could log in the eye-PACS to observe fundus images and reports. Multipurpose internet mail extensions (MIME) type of a structured report is saved as pdf/html with reference link to relevant fundus image using the WADO syntax could provide enough information for clinicians. Some functions provided by open-source Oviyam could be used to query, zoom, move, measure, view DICOM fundus images. Such web eye-PACS in compliance to WADO protocol could be used to store and communicate fundus images and reports, therefore is of great significance for teleophthalmology.

Portable Brain-Computer Interface for the Intensive Care Unit Patient Communication Using Subject-Dependent SSVEP Identification.

PubMed

Dehzangi, Omid; Farooq, Muhamed

2018-01-01

A major predicament for Intensive Care Unit (ICU) patients is inconsistent and ineffective communication means. Patients rated most communication sessions as difficult and unsuccessful. This, in turn, can cause distress, unrecognized pain, anxiety, and fear. As such, we designed a portable BCI system for ICU communications (BCI4ICU) optimized to operate effectively in an ICU environment. The system utilizes a wearable EEG cap coupled with an Android app designed on a mobile device that serves as visual stimuli and data processing module. Furthermore, to overcome the challenges that BCI systems face today in real-world scenarios, we propose a novel subject-specific Gaussian Mixture Model- (GMM-) based training and adaptation algorithm. First, we incorporate subject-specific information in the training phase of the SSVEP identification model using GMM-based training and adaptation. We evaluate subject-specific models against other subjects. Subsequently, from the GMM discriminative scores, we generate the transformed vectors, which are passed to our predictive model. Finally, the adapted mixture mean scores of the subject-specific GMMs are utilized to generate the high-dimensional supervectors. Our experimental results demonstrate that the proposed system achieved 98.7% average identification accuracy, which is promising in order to provide effective and consistent communication for patients in the intensive care.

High-speed photodetectors in optical communication system

NASA Astrophysics Data System (ADS)

Zhao, Zeping; Liu, Jianguo; Liu, Yu; Zhu, Ninghua

2017-12-01

This paper presents a review and discussion for high-speed photodetectors and their applications on optical communications and microwave photonics. A detailed and comprehensive demonstration of high-speed photodetectors from development history, research hotspots to packaging technologies is provided to the best of our knowledge. A few typical applications based on photodetectors are also illustrated, such as free-space optical communications, radio over fiber and millimeter terahertz signal generation systems. Project supported by the Preeminence Youth Fund of China (No. 61625504).

System concepts and design examples for optical communication with planetary spacecraft

NASA Astrophysics Data System (ADS)

Lesh, James R.

Systems concepts for optical communication with future deep-space (planetary) spacecraft are described. These include not only the optical transceiver package aboard the distant spacecraft, but the earth-vicinity optical-communications receiving station as well. Both ground-based, and earth-orbiting receivers are considered. Design examples for a number of proposed or potential deep-space missions are then presented. These include an orbital mission to Saturn, a Lander and Rover mission to Mars, and an astronomical mission to a distance of 1000 astronomical units.

Performance analysis of a coherent free space optical communication system based on experiment.

PubMed

Cao, Jingtai; Zhao, Xiaohui; Liu, Wei; Gu, Haijun

2017-06-26

Based on our previous study and designed experimental AO system with a 97-element continuous surface deformable mirror, we conduct the performance analysis of a coherent free space optical communication (FSOC) system for mixing efficiency (ME), bit error rate (BER) and outage probability under different Greenwood frequency and atmospheric coherent length. The results show that the influence of the atmospheric temporal characteristics on the performance is slightly stronger than that of the spatial characteristics when the receiving aperture and the number of sub-apertures are given. This analysis result provides a reference for the design of the coherent FSOC system.

An Online Banking System Based on Quantum Cryptography Communication

NASA Astrophysics Data System (ADS)

Zhou, Ri-gui; Li, Wei; Huan, Tian-tian; Shen, Chen-yi; Li, Hai-sheng

2014-07-01

In this paper, an online banking system has been built. Based on quantum cryptography communication, this system is proved unconditional secure. Two sets of GHZ states are applied, which can ensure the safety of purchase and payment, respectively. In another word, three trading participants in each triplet state group form an interdependent and interactive relationship. In the meantime, trading authorization and blind signature is introduced by means of controllable quantum teleportation. Thus, an effective monitor is practiced on the premise that the privacy of trading partners is guaranteed. If there is a dispute or deceptive behavior, the system will find out the deceiver immediately according to the relationship mentioned above.

Large Scale Portability of Hospital Information System Software

PubMed Central

Munnecke, Thomas H.; Kuhn, Ingeborg M.

1986-01-01

As part of its Decentralized Hospital Computer Program (DHCP) the Veterans Administration installed new hospital information systems in 169 of its facilities during 1984 and 1985. The application software for these systems is based on the ANS MUMPS language, is public domain, and is designed to be operating system and hardware independent. The software, developed by VA employees, is built upon a layered approach, where application packages layer on a common data dictionary which is supported by a Kernel of software. Communications between facilities are based on public domain Department of Defense ARPA net standards for domain naming, mail transfer protocols, and message formats, layered on a variety of communications technologies.

Performance Assessment of a Communicable Disease Surveillance System in Response to the Twin Earthquakes of East Azerbaijan.

PubMed

Babaie, Javad; Ardalan, Ali; Vatandoost, Hasan; Goya, Mohammad Mehdi; Akbari Sari, Ali

2015-08-01

Following the twin earthquakes on August 11, 2012, in the East Azerbaijan province of Iran, the provincial health center set up a surveillance system to monitor communicable diseases. This study aimed to assess the performance of this surveillance system. In this quantitative-qualitative study, performance of the communicable diseases surveillance system was assessed by using the updated guidelines of the Centers for Disease Control and Prevention (CDC). Qualitative data were collected through interviews with the surveillance system participants, and quantitative data were obtained from the surveillance system. The surveillance system was useful, simple, representative, timely, and flexible. The data quality, acceptability, and stability of the surveillance system were 65.6%, 10.63%, and 100%, respectively. The sensitivity and positive predictive value were not calculated owing to the absence of a gold standard. The surveillance system satisfactorily met the goals expected for its setup. The data obtained led to the control of communicable diseases in the affected areas. Required interventions based on the incidence of communicable disease were designed and implemented. The results also reassured health authorities and the public. However, data quality and acceptability should be taken into consideration and reviewed for implementation in future disasters.

Game theory-based mode cooperative selection mechanism for device-to-device visible light communication

NASA Astrophysics Data System (ADS)

Liu, Yuxin; Huang, Zhitong; Li, Wei; Ji, Yuefeng

2016-03-01

Various patterns of device-to-device (D2D) communication, from Bluetooth to Wi-Fi Direct, are emerging due to the increasing requirements of information sharing between mobile terminals. This paper presents an innovative pattern named device-to-device visible light communication (D2D-VLC) to alleviate the growing traffic problem. However, the occlusion problem is a difficulty in D2D-VLC. This paper proposes a game theory-based solution in which the best-response dynamics and best-response strategies are used to realize a mode-cooperative selection mechanism. This mechanism uses system capacity as the utility function to optimize system performance and selects the optimal communication mode for each active user from three candidate modes. Moreover, the simulation and experimental results show that the mechanism can attain a significant improvement in terms of effectiveness and energy saving compared with the cases where the users communicate via only the fixed transceivers (light-emitting diode and photo diode) or via only D2D.

Intersatellite Link (ISL) application to commercial communications satellites. Volume 1: Executive summary

NASA Technical Reports Server (NTRS)

Young, S. Lee

1987-01-01

Based on a comprehensive evaluation of the fundamental Intersatellite Link (ISL) systems characteristics, potential applications of ISLs to domestic, regional, and global commercial satellite communications were identified, and their cost-effectiveness and other systems benefits quantified wherever possible. Implementation scenarios for the cost-effective communications satellite systems employing ISLs were developed for the first launch in 1993 to 1994 and widespread use of ISLs in the early 2000's. Critical technology requirements for both the microwave (60 GHz) and optical (0.85 micron) ISL implementations were identified, and their technology development programs, including schedule and cost estimates, were derived.

A satellite-based personal communication system for the 21st century

NASA Technical Reports Server (NTRS)

Sue, Miles K.; Dessouky, Khaled; Levitt, Barry; Rafferty, William

1990-01-01

Interest in personal communications (PCOMM) has been stimulated by recent developments in satellite and terrestrial mobile communications. A personal access satellite system (PASS) concept was developed at the Jet Propulsion Laboratory (JPL) which has many attractive user features, including service diversity and a handheld terminal. Significant technical challenges addressed in formulating the PASS space and ground segments are discussed. PASS system concept and basic design features, high risk enabling technologies, an optimized multiple access scheme, alternative antenna coverage concepts, the use of non-geostationary orbits, user terminal radiation constraints, and user terminal frequency reference are covered.

Proceedings of the Mobile Satellite Conference

NASA Technical Reports Server (NTRS)

Rafferty, William

1988-01-01

A satellite-based mobile communications system provides voice and data communications to mobile users over a vast geographic area. The technical and service characteristics of mobile satellite systems (MSSs) are presented and form an in-depth view of the current MSS status at the system and subsystem levels. Major emphasis is placed on developments, current and future, in the following critical MSS technology areas: vehicle antennas, networking, modulation and coding, speech compression, channel characterization, space segment technology and MSS experiments. Also, the mobile satellite communications needs of government agencies are addressed, as is the MSS potential to fulfill them.

The Impact Of Multimode Fiber Chromatic Dispersion On Data Communications

NASA Astrophysics Data System (ADS)

Hackert, Michael J.

1990-01-01

Capability for the lowest cost is the goal of contemporary communications managers. With all of the competitive pressures that modern businesses are experiencing these days, communications needs must be met with the most information carrying capacity for the lowest cost. Optical fiber communication systems meet these requirements while providing reliability, system integrity, and potential future upgradability. Consequently, optical fiber is finding numerous applications in addition to its traditional telephony plant. Fiber based systems are meeting these requirements in building networks and computer interconnects at a lower cost than copper based systems. A fiber type being chosen by industry to meet these needs in standard systems such as FDDI, is multimode fiber. Multimode fiber systems offer cost advantages over single-mode fiber through lower fiber connection costs. Also, system designers can gain savings by using low cost, high reliability, wide spectral width sources such as LEDs instead of lasers and by operating at higher bit rates than used for multimode systems in the past. However, in order to maximize the cost savings while ensuring the system will operate as intended, the chromatic dispersion of the fiber must be taken into account. This paper explains how to do that and shows how to calculate multimode chromatic dispersion for each of the standard fiber sizes (50 μm, 62.5 μm, 85 μm, and 100μm core diameter).

Security Policy for a Generic Space Exploration Communication Network Architecture

NASA Technical Reports Server (NTRS)

Ivancic, William D.; Sheehe, Charles J.; Vaden, Karl R.

2016-01-01

This document is one of three. It describes various security mechanisms and a security policy profile for a generic space-based communication architecture. Two other documents accompany this document- an Operations Concept (OpsCon) and a communication architecture document. The OpsCon should be read first followed by the security policy profile described by this document and then the architecture document. The overall goal is to design a generic space exploration communication network architecture that is affordable, deployable, maintainable, securable, evolvable, reliable, and adaptable. The architecture should also require limited reconfiguration throughout system development and deployment. System deployment includes subsystem development in a factory setting, system integration in a laboratory setting, launch preparation, launch, and deployment and operation in space.

Proceedings of the Third International Mobile Satellite Conference (IMSC 1993)

NASA Technical Reports Server (NTRS)

Kwan, Robert (Compiler); Rigley, Jack (Compiler); Cassingham, Randy (Editor)

1993-01-01

Satellite-based mobile communications systems provide voice and data communications to users over a vast geographic area. The users may communicate via mobile or hand-held terminals, which may also provide access to terrestrial cellular communications services. While the first and second International Mobile Satellite Conferences (IMSC) mostly concentrated on technical advances, this Third IMSC also focuses on the increasing worldwide commercial activities in Mobile Satellite Services. Because of the large service areas provided by such systems, it is important to consider political and regulatory issues in addition to technical and user requirements issues. Topics covered include: the direct broadcast of audio programming from satellites; spacecraft technology; regulatory and policy considerations; advanced system concepts and analysis; propagation; and user requirements and applications.

Distributed-observer-based cooperative control for synchronization of linear discrete-time multi-agent systems.

PubMed

Liang, Hongjing; Zhang, Huaguang; Wang, Zhanshan

2015-11-01

This paper considers output synchronization of discrete-time multi-agent systems with directed communication topologies. The directed communication graph contains a spanning tree and the exosystem as its root. Distributed observer-based consensus protocols are proposed, based on the relative outputs of neighboring agents. A multi-step algorithm is presented to construct the observer-based protocols. In light of the discrete-time algebraic Riccati equation and internal model principle, synchronization problem is completed. At last, numerical simulation is provided to verify the effectiveness of the theoretical results. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

CHIMERA II - A real-time multiprocessing environment for sensor-based robot control

NASA Technical Reports Server (NTRS)

Stewart, David B.; Schmitz, Donald E.; Khosla, Pradeep K.

1989-01-01

A multiprocessing environment for a wide variety of sensor-based robot system, providing the flexibility, performance, and UNIX-compatible interface needed for fast development of real-time code is addressed. The requirements imposed on the design of a programming environment for sensor-based robotic control is outlined. The details of the current hardware configuration are presented, along with the details of the CHIMERA II software. Emphasis is placed on the kernel, low-level interboard communication, user interface, extended file system, user-definable and dynamically selectable real-time schedulers, remote process synchronization, and generalized interprocess communication. A possible implementation of a hierarchical control model, the NASA/NBS standard reference model for telerobot control system is demonstrated.

Building a gateway with open source software for secure-DICOM communication over insecure networks

NASA Astrophysics Data System (ADS)

Emmel, Dirk; Ricke, Jens; Stohlmann, Lutz; Haderer, Alexander; Felix, Roland

2002-05-01

For Teleradiology the exchange of DICOM-images is needed for several purposes. Existing solutions often don't consider about the needs for data security and data privacy. Communication is done without any encryption over insecure networks or with encryption using proprietary solutions, which reduces the data communication possibilities to partners with the same equipment. Our goal was to build a gateway, which offers a transparent solution for secure DICOM-communication in a heterogeneous environment We developed a PC-based gateway system with DICOM-communication to the in-house network and secure DICOM communication for the communication over the insecure network. One gateway installed at each location is responsible for encryption/decryption. The sender just transfers the image data over the DICOM protocol to the local gateway. The gateway forwards the data to the gateway on the destination site using the secure DICOM protocol, which is part of the DICOM standard. The receiving gateway forwards the image data to the final destination again using the DICOM-Protocol. The gateway is based on Open Source software and runs under several operating systems. Our experience shows a reliable solution, which solves security issues for DICOM communication of image data and integrates seamless into a heterogeneous DICOM environment.

Mars Laser Communication Demonstration, Artist's Concept

NASA Technical Reports Server (NTRS)

2005-01-01

This illustration depicts a concept for operation of an optical communications system on NASA's Mars Telecommunications Orbiter. The orbiter is in development for launch in September 2009 with a payload including the spacecraft terminal of the Mars Laser Communication Demonstration Project. This project will also include an Earth-based terminal for two-way, high-data-rate communication using infrared light. The orbiter's primary communications with Earth will use radio frequencies. The laser demonstration is intended to build experience for use in decisions about possible use of optical communications by later missions.

[Communication management of collaborative networks of science, technology and innovation in health].

PubMed

Martins, Wagner de Jesus; Artmann, Elizabeth; Rivera, Francisco Javier Uribe

2012-12-01

The objective of the article was to propose a model of communication management of networks for the Health Innovation System in Brazil. The health production complex and its relationship with the nation's development are addressed and some suggestions for operationalization of the proposed model are also presented. The discussion is based on Habermas' theory and similar cases from other countries. Communication strategies and approaches to commitment dialogue for concerted actions and consensus-building based on critical reasoning may help strengthen democratic networks.

Least mean square fourth based microgrid state estimation algorithm using the internet of things technology.

PubMed

Rana, Md Masud

2017-01-01

This paper proposes an innovative internet of things (IoT) based communication framework for monitoring microgrid under the condition of packet dropouts in measurements. First of all, the microgrid incorporating the renewable distributed energy resources is represented by a state-space model. The IoT embedded wireless sensor network is adopted to sense the system states. Afterwards, the information is transmitted to the energy management system using the communication network. Finally, the least mean square fourth algorithm is explored for estimating the system states. The effectiveness of the developed approach is verified through numerical simulations.

Flexible distributed architecture for semiconductor process control and experimentation

NASA Astrophysics Data System (ADS)

Gower, Aaron E.; Boning, Duane S.; McIlrath, Michael B.

1997-01-01

Semiconductor fabrication requires an increasingly expensive and integrated set of tightly controlled processes, driving the need for a fabrication facility with fully computerized, networked processing equipment. We describe an integrated, open system architecture enabling distributed experimentation and process control for plasma etching. The system was developed at MIT's Microsystems Technology Laboratories and employs in-situ CCD interferometry based analysis in the sensor-feedback control of an Applied Materials Precision 5000 Plasma Etcher (AME5000). Our system supports accelerated, advanced research involving feedback control algorithms, and includes a distributed interface that utilizes the internet to make these fabrication capabilities available to remote users. The system architecture is both distributed and modular: specific implementation of any one task does not restrict the implementation of another. The low level architectural components include a host controller that communicates with the AME5000 equipment via SECS-II, and a host controller for the acquisition and analysis of the CCD sensor images. A cell controller (CC) manages communications between these equipment and sensor controllers. The CC is also responsible for process control decisions; algorithmic controllers may be integrated locally or via remote communications. Finally, a system server images connections from internet/intranet (web) based clients and uses a direct link with the CC to access the system. Each component communicates via a predefined set of TCP/IP socket based messages. This flexible architecture makes integration easier and more robust, and enables separate software components to run on the same or different computers independent of hardware or software platform.

Evaluation of components, subsystems, and networks for high rate, high frequency space communications

NASA Technical Reports Server (NTRS)

Kerczewski, Robert J.; Ivancic, William D.; Zuzek, John E.

1991-01-01

The development of new space communications technologies by NASA has included both commercial applications and space science requirements. At NASA's Lewis Research Center, methods and facilities have been developed for evaluating these new technologies in the laboratory. NASA's Systems Integration, Test and Evaluation (SITE) Space Communication System Simulator is a hardware-based laboratory simulator for evaluating space communications technologies at the component, subsystem, system, and network level, geared toward high frequency, high data rate systems. The SITE facility is well-suited for evaluation of the new technologies required for the Space Exploration Initiative (SEI) and advanced commercial systems. This paper describes the technology developments and evaluation requirements for current and planned commercial and space science programs. Also examined are the capabilities of SITE, the past, present, and planned future configurations of the SITE facility, and applications of SITE to evaluation of SEI technology.

The picture exchange communication system.

PubMed

Bondy, A S; Frost, L A

1998-01-01

The Picture Exchange Communication System (PECS) was developed as a means to teach children with autism and related developmental disabilities a rapidly acquired, self-initiating, functional communication system. Its theoretical roots combine principles from applied behavior analysis and guidelines established within the field of alternative and augmentative communication. This approach has several potential advantages relative to imitation-based strategies (both vocal and gestural) and symbol selection strategies. The system begins with the exchange of simple icons but rapidly builds "sentence" structure. The system also emphasizes developing the request function prior to developing responding to simple questions and commenting. The development of requesting with a sentence structure also permits the rapid development of attributes more traditionally taught within a receptive mode. The relationship between the introduction of PECS and various other behavioral issues (i.e., social approach and behavior management) as well as its relationship to the codevelopment of speech are reviewed.

Concepts for image management and communication system for space vehicle health management

NASA Astrophysics Data System (ADS)

Alsafadi, Yasser; Martinez, Ralph

On a space vehicle, the Crew Health Care System will handle minor accidents or illnesses immediately, thereby eliminating the necessity of early mission termination or emergency rescue. For practical reasons, only trained personnel with limited medical experience can be available on space vehicles to render preliminary health care. There is the need to communicate with medical experts at different locations on earth. Interplanetary Image Management and Communication System (IIMACS) will be a bridge between worlds and deliver medical images acquired in space to physicians at different medical centers on earth. This paper discusses the implementation of IIMACS by extending the Global Picture Archiving and Communication System (GPACS) being developed to interconnect medical centers on earth. Furthermore, this paper explores system requirements of IIMACS and different user scenarios. Our conclusion is that IIMACS is feasible using the maturing technology base of GPACS.

Effects of Picture Exchange Communication System on Communication and Behavioral Anomalies in Autism

PubMed Central

Malhotra, Shahzadi; Rajender, Gaurav; Bhatia, Manjeet S.; Singh, Tej B.

2010-01-01

Communication skills deficits and stereotyped behaviors are frequently found among people with pervasive developmental disabilities like autism. These communication and behavioral oddities of autism are often considered to be difficult to treat and are challenging. Picture exchange communication system (PECS) is a six-phase picture system based on applied behavior analysis and is specially designed to overcome these communication difficulties in children with autism by encouraging the child to be the communication initiator. The present paper throws light on the process of using PECS along with other traditional behavioral approaches in managing communication deficits and behavioral stereotypies in a seven-year-old male child diagnosed as having childhood autism. The identified target behaviors of repeated head turning, flapping his hands, poor communication skills were assessed using various rating scales including visual analogue scale as per clinician observation and parental reports and managed using PECS as an adjunct to traditional behavioral techniques of contingency management, differential reinforcement, task direction and reprimand. Outcome was assessed using same tools after thirty-two sessions of interventions spread over three months. Significant improvements of around 60% were observed in the target behaviors. PMID:21716776

Effects of picture exchange communication system on communication and behavioral anomalies in autism.

PubMed

Malhotra, Shahzadi; Rajender, Gaurav; Bhatia, Manjeet S; Singh, Tej B

2010-07-01

Communication skills deficits and stereotyped behaviors are frequently found among people with pervasive developmental disabilities like autism. These communication and behavioral oddities of autism are often considered to be difficult to treat and are challenging. Picture exchange communication system (PECS) is a six-phase picture system based on applied behavior analysis and is specially designed to overcome these communication difficulties in children with autism by encouraging the child to be the communication initiator. The present paper throws light on the process of using PECS along with other traditional behavioral approaches in managing communication deficits and behavioral stereotypies in a seven-year-old male child diagnosed as having childhood autism. The identified target behaviors of repeated head turning, flapping his hands, poor communication skills were assessed using various rating scales including visual analogue scale as per clinician observation and parental reports and managed using PECS as an adjunct to traditional behavioral techniques of contingency management, differential reinforcement, task direction and reprimand. Outcome was assessed using same tools after thirty-two sessions of interventions spread over three months. Significant improvements of around 60% were observed in the target behaviors.

Hierarchy of conversational rule violations involving utterance-based augmentative and alternative communication systems.

PubMed

Hoag, Linda A; Bedrosian, Jan L; McCoy, Kathleen F; Johnson, Dallas E

2008-01-01

This study examined the effects of using messages with conversational rule violations on attitudes toward people who used utterance-based augmentative and alternative communication (AAC) systems in transactional interactions. Specifically, the ratings were compared across messages with relevance, informativeness, and brevity violations, when latency remained constant (i.e., short). The 96 participating sales clerks viewed scripted, videotaped bookstore conversations and completed an attitude questionnaire. Results indicated that the prestored message with repeated words/phrases was rated the highest, followed by the message with excessive information; next was the message with inadequate information, followed by the message with partly relevant information. The findings may be useful to those using utterance-based systems when making message choices during interactions with service providers. Technological implications point to the development of schema/script-based systems and intelligent editing.

Objective Metric Based Assessments for Efficient Evaluation of Auditory Situation Awareness Characteristics of Tactical Communications and Protective Systems (TCAPS) and Augmented Hearing Protective Devices (HPDs)

DTIC Science & Technology

2015-11-30

Assessments for Efficient Evaluation of Auditory Situation Awareness Characteristics of Tactical Communications and Protective Systems (TCAPS) and Augmented...Hearing Protective Devices (HPDs) W81XWH-13-C-0193 John G. Casali, Ph.D, CPE & Kichol Lee, Ph.D Auditory Systems Lab, Industrial and Systems ...Suite 1 JBSA Lackland, TX 78236-9908 Approved for public release: distribution unlimited. The Virginia Tech Auditory Systems Laboratory (ASL

Feasibility Study on a Portable Field Pest Classification System Design Based on DSP and 3G Wireless Communication Technology

PubMed Central

Han, Ruizhen; He, Yong; Liu, Fei

2012-01-01

This paper presents a feasibility study on a real-time in field pest classification system design based on Blackfin DSP and 3G wireless communication technology. This prototype system is composed of remote on-line classification platform (ROCP), which uses a digital signal processor (DSP) as a core CPU, and a host control platform (HCP). The ROCP is in charge of acquiring the pest image, extracting image features and detecting the class of pest using an Artificial Neural Network (ANN) classifier. It sends the image data, which is encoded using JPEG 2000 in DSP, to the HCP through the 3G network at the same time for further identification. The image transmission and communication are accomplished using 3G technology. Our system transmits the data via a commercial base station. The system can work properly based on the effective coverage of base stations, no matter the distance from the ROCP to the HCP. In the HCP, the image data is decoded and the pest image displayed in real-time for further identification. Authentication and performance tests of the prototype system were conducted. The authentication test showed that the image data were transmitted correctly. Based on the performance test results on six classes of pests, the average accuracy is 82%. Considering the different live pests’ pose and different field lighting conditions, the result is satisfactory. The proposed technique is well suited for implementation in field pest classification on-line for precision agriculture. PMID:22736996

Feasibility study on a portable field pest classification system design based on DSP and 3G wireless communication technology.

PubMed

Han, Ruizhen; He, Yong; Liu, Fei

2012-01-01

This paper presents a feasibility study on a real-time in field pest classification system design based on Blackfin DSP and 3G wireless communication technology. This prototype system is composed of remote on-line classification platform (ROCP), which uses a digital signal processor (DSP) as a core CPU, and a host control platform (HCP). The ROCP is in charge of acquiring the pest image, extracting image features and detecting the class of pest using an Artificial Neural Network (ANN) classifier. It sends the image data, which is encoded using JPEG 2000 in DSP, to the HCP through the 3G network at the same time for further identification. The image transmission and communication are accomplished using 3G technology. Our system transmits the data via a commercial base station. The system can work properly based on the effective coverage of base stations, no matter the distance from the ROCP to the HCP. In the HCP, the image data is decoded and the pest image displayed in real-time for further identification. Authentication and performance tests of the prototype system were conducted. The authentication test showed that the image data were transmitted correctly. Based on the performance test results on six classes of pests, the average accuracy is 82%. Considering the different live pests' pose and different field lighting conditions, the result is satisfactory. The proposed technique is well suited for implementation in field pest classification on-line for precision agriculture.

Learning Intercultural Communication Skills with Virtual Humans: Feedback and Fidelity

ERIC Educational Resources Information Center

Lane, H. Chad; Hays, Matthew Jensen; Core, Mark G.; Auerbach, Daniel

2013-01-01

In the context of practicing intercultural communication skills, we investigated the role of fidelity in a game-based, virtual learning environment as well as the role of feedback delivered by an intelligent tutoring system. In 2 experiments, we compared variations on the game interface, use of the tutoring system, and the form of the feedback.…

Encrypted IP video communication system

NASA Astrophysics Data System (ADS)

Bogdan, Apetrechioaie; Luminiţa, Mateescu

2010-11-01

Digital video transmission is a permanent subject of development, research and improvement. This field of research has an exponentially growing market in civil, surveillance, security and military aplications. A lot of solutions: FPGA, ASIC, DSP have been used for this purpose. The paper presents the implementation of an encrypted, IP based, video communication system having a competitive performance/cost ratio .

Communications and Tracking Distributed Systems Evolution Study

NASA Technical Reports Server (NTRS)

Culpepper, William

1990-01-01

The Communications and Tracking (C & T) techniques and equipment to support evolutionary space station concepts are being analyzed. Evolutionary space station configurations and operational concepts are used to derive the results to date. A description of the C & T system based on future capability needs is presented. Included are the hooks and scars currently identified to support future growth.

The Internet as a Medium of Training for Picture Archival and Communication Systems (PACS).

ERIC Educational Resources Information Center

Majid, Shaheen; Misra, Ramesh Kumar

2002-01-01

Explores the potential of Web-based training for PACS (Picture Archival and Communication Systems) used in radiology departments for the storage and archiving of patients' medical images. Reports results of studies in three hospitals in Malaysia, Singapore and the Philippines that showed that the Internet can be used effectively for training.…

Indoor visible light communication localization system utilizing received signal strength indication technique and trilateration method

NASA Astrophysics Data System (ADS)

Mousa, Farag I. K.; Almaadeed, Noor; Busawon, Krishna; Bouridane, Ahmed; Binns, Richard; Elliot, Ian

2018-01-01

Visible light communication (VLC) based on light-emitting diodes (LEDs) technology not only provides higher data rate for indoor wireless communications and offering room illumination but also has the potential for indoor localization. VLC-based indoor positioning using the received optical power levels from emitting LEDs is investigated. We consider both scenarios of line-of-sight (LOS) and LOS with non-LOS (LOSNLOS) positioning. The performance of the proposed system is evaluated under both noisy and noiseless channel as is the impact of different location codes on positioning error. The analytical model of the system with noise and the corresponding numerical evaluation for a range of signal-to-noise ratio (SNR) are presented. The results show that an accuracy of <10 cm on average is achievable at an SNR>12 dB.

An Evolvable Multi-Agent Approach to Space Operations Engineering

NASA Technical Reports Server (NTRS)

Mandutianu, Sanda; Stoica, Adrian

1999-01-01

A complex system of spacecraft and ground tracking stations, as well as a constellation of satellites or spacecraft, has to be able to reliably withstand sudden environment changes, resource fluctuations, dynamic resource configuration, limited communication bandwidth, etc., while maintaining the consistency of the system as a whole. It is not known in advance when a change in the environment might occur or when a particular exchange will happen. A higher degree of sophistication for the communication mechanisms between different parts of the system is required. The actual behavior has to be determined while the system is performing and the course of action can be decided at the individual level. Under such circumstances, the solution will highly benefit from increased on-board and on the ground adaptability and autonomy. An evolvable architecture based on intelligent agents that communicate and cooperate with each other can offer advantages in this direction. This paper presents an architecture of an evolvable agent-based system (software and software/hardware hybrids) as well as some plans for further implementation.

A review on technologies and their usage in solid waste monitoring and management systems: Issues and challenges.

PubMed

Hannan, M A; Abdulla Al Mamun, Md; Hussain, Aini; Basri, Hassan; Begum, R A

2015-09-01

In the backdrop of prompt advancement, information and communication technology (ICT) has become an inevitable part to plan and design of modern solid waste management (SWM) systems. This study presents a critical review of the existing ICTs and their usage in SWM systems to unfold the issues and challenges towards using integrated technologies based system. To plan, monitor, collect and manage solid waste, the ICTs are divided into four categories such as spatial technologies, identification technologies, data acquisition technologies and data communication technologies. The ICT based SWM systems classified in this paper are based on the first three technologies while the forth one is employed by almost every systems. This review may guide the reader about the basics of available ICTs and their application in SWM to facilitate the search for planning and design of a sustainable new system. Copyright © 2015 Elsevier Ltd. All rights reserved.

Line of sight pointing technology for laser communication system between aircrafts

NASA Astrophysics Data System (ADS)

Zhao, Xin; Liu, Yunqing; Song, Yansong

2017-12-01

In space optical communications, it is important to obtain the most efficient performance of line of sight (LOS) pointing system. The errors of position (latitude, longitude, and altitude), attitude angles (pitch, yaw, and roll), and installation angle among a different coordinates system are usually ineluctable when assembling and running an aircraft optical communication terminal. These errors would lead to pointing errors and make it difficult for the LOS system to point to its terminal to establish a communication link. The LOS pointing technology of an aircraft optical communication system has been researched using a transformation matrix between the coordinate systems of two aircraft terminals. A method of LOS calibration has been proposed to reduce the pointing error. In a flight test, a successful 144-km link was established between two aircrafts. The position and attitude angles of the aircraft have been obtained to calculate the pointing angle in azimuth and elevation provided by using a double-antenna GPS/INS system. The size of the field of uncertainty (FOU) and the pointing accuracy are analyzed based on error theory, and it has been also measured using an observation camera installed next to the optical LOS. Our results show that the FOU of aircraft optical communications is 10 mrad without a filter, which is the foundation to acquisition strategy and scanning time.

DDS as middleware of the Southern African Large Telescope control system

NASA Astrophysics Data System (ADS)

Maartens, Deneys S.; Brink, Janus D.

2016-07-01

The Southern African Large Telescope (SALT) software control system1 is realised as a distributed control system, implemented predominantly in National Instruments' LabVIEW. The telescope control subsystems communicate using cyclic, state-based messages. Currently, transmitting a message is accomplished by performing an HTTP PUT request to a WebDAV directory on a centralised Apache web server, while receiving is based on polling the web server for new messages. While the method works, it presents a number of drawbacks; a scalable distributed communication solution with minimal overhead is a better fit for control systems. This paper describes our exploration of the Data Distribution Service (DDS). DDS is a formal standard specification, defined by the Object Management Group (OMG), that presents a data-centric publish-subscribe model for distributed application communication and integration. It provides an infrastructure for platform- independent many-to-many communication. A number of vendors provide implementations of the DDS standard; RTI, in particular, provides a DDS toolkit for LabVIEW. This toolkit has been evaluated against the needs of SALT, and a few deficiencies have been identified. We have developed our own implementation that interfaces LabVIEW to DDS in order to address our specific needs. Our LabVIEW DDS interface implementation is built against the RTI DDS Core component, provided by RTI under their Open Community Source licence. Our needs dictate that the interface implementation be platform independent. Since we have access to the RTI DDS Core source code, we are able to build the RTI DDS libraries for any of the platforms on which we require support. The communications functionality is based on UDP multicasting. Multicasting is an efficient communications mechanism with low overheads which avoids duplicated point-to-point transmission of data on a network where there are multiple recipients of the data. In the paper we present a performance evaluation of DDS against the current HTTP-based implementation as well as the historical DataSocket implementation. We conclude with a summary and describe future work.

Wireless Control of Miniaturized Mobile Vehicle for Indoor Surveillance

NASA Astrophysics Data System (ADS)

Taha Saquib, Syed M.; Hameed, Sarmad; Usman Ali, Syed M.; Jafri, Raza; Amin, Imran

2013-12-01

This work is based upon electronic automation and Smart Control techniques, which constitute the basis of Control Area Network (CAN) and Personal Area Network (PAN). Bluetooth technology has been interfaced with a programmable controller to provide multi-dimensional vehicle control. A network is proposed which contains a remote, mobile host controller and an android operating system based mobile set (Client). The client communicates with a host controller through a Bluetooth device. The system incorporates duplex communication after successful confirmation between the host and the client; the android based mobile unit controls the vehicle through the Bluetooth module.

Underwater optical communications using orbital angular momentum-based spatial division multiplexing

NASA Astrophysics Data System (ADS)

Willner, Alan E.; Zhao, Zhe; Ren, Yongxiong; Li, Long; Xie, Guodong; Song, Haoqian; Liu, Cong; Zhang, Runzhou; Bao, Changjing; Pang, Kai

2018-02-01

In this paper, we review high-capacity underwater optical communications using orbital angular momentum (OAM)-based spatial division multiplexing. We discuss methods to generate and detect blue-green optical data-carrying OAM beams as well as various underwater effects, including attenuation, scattering, current, and thermal gradients on OAM beams. Attention is also given to the system performance of high-capacity underwater optical communication links using OAM-based space division multiplexing. The paper closes with a discussion of a digital signal processing (DSP) algorithm to mitigate the inter-mode crosstalk caused by thermal gradients.

Development of Communication Assistive Technology for Persons with Deaf-Blindness and Physical Limitation.

PubMed

Hatakeyama, Takuro; Watanabe, Takashi; Takahashi, Kiriko; Doi, Kouki; Fukuda, Akiko

2015-01-01

The purpose of this study was to develop a system that will provide communication assistance to persons with deaf-blindness and physical limitation, so that they will be able to communicate with others without the help of an interpreter. With this communication system, a person with deaf-blindness and physical limitation uses a control switch to perform input operations based on the duration of the operating time and combination of long and short pulses. When the input is correctly performed, the user receives a feedback from the tablet computer as vibratory stimuli. Similarly, the message that other person's input with a Bluetooth keyboard is transmitted to the user as vibration stimuli. Following the development, we conducted a one-year assessment of the developed communication system in an actual environment with the cooperation of one person with deaf-blindness and physical limitation. . We confirmed that our developed system was useful for such a person, and understood that we must improve upon several aspects. We shall pursue further study, and will aim at providing a better communication environment for persons with deaf-blindness and physical limitation in future.

Local search to improve coordinate-based task mapping

DOE PAGES

Balzuweit, Evan; Bunde, David P.; Leung, Vitus J.; ...

2015-10-31

We present a local search strategy to improve the coordinate-based mapping of a parallel job’s tasks to the MPI ranks of its parallel allocation in order to reduce network congestion and the job’s communication time. The goal is to reduce the number of network hops between communicating pairs of ranks. Our target is applications with a nearest-neighbor stencil communication pattern running on mesh systems with non-contiguous processor allocation, such as Cray XE and XK Systems. Utilizing the miniGhost mini-app, which models the shock physics application CTH, we demonstrate that our strategy reduces application running time while also reducing the runtimemore » variability. Furthermore, we further show that mapping quality can vary based on the selected allocation algorithm, even between allocation algorithms of similar apparent quality.« less

Design and implementation of a remote UAV-based mobile health monitoring system

NASA Astrophysics Data System (ADS)

Li, Songwei; Wan, Yan; Fu, Shengli; Liu, Mushuang; Wu, H. Felix

2017-04-01

Unmanned aerial vehicles (UAVs) play increasing roles in structure health monitoring. With growing mobility in modern Internet-of-Things (IoT) applications, the health monitoring of mobile structures becomes an emerging application. In this paper, we develop a UAV-carried vision-based monitoring system that allows a UAV to continuously track and monitor a mobile infrastructure and transmit back the monitoring information in real- time from a remote location. The monitoring system uses a simple UAV-mounted camera and requires only a single feature located on the mobile infrastructure for target detection and tracking. The computation-effective vision-based tracking solution based on a single feature is an improvement over existing vision-based lead-follower tracking systems that either have poor tracking performance due to the use of a single feature, or have improved tracking performance at a cost of the usage of multiple features. In addition, a UAV-carried aerial networking infrastructure using directional antennas is used to enable robust real-time transmission of monitoring video streams over a long distance. Automatic heading control is used to self-align headings of directional antennas to enable robust communication in mobility. Compared to existing omni-communication systems, the directional communication solution significantly increases the operation range of remote monitoring systems. In this paper, we develop the integrated modeling framework of camera and mobile platforms, design the tracking algorithm, develop a testbed of UAVs and mobile platforms, and evaluate system performance through both simulation studies and field tests.

A performance study of unmanned aerial vehicle-based sensor networks under cyber attack

NASA Astrophysics Data System (ADS)

Puchaty, Ethan M.

In UAV-based sensor networks, an emerging area of interest is the performance of these networks under cyber attack. This study seeks to evaluate the performance trade-offs from a System-of-Systems (SoS) perspective between various UAV communications architecture options in the context two missions: tracking ballistic missiles and tracking insurgents. An agent-based discrete event simulation is used to model a sensor communication network consisting of UAVs, military communications satellites, ground relay stations, and a mission control center. Network susceptibility to cyber attack is modeled with probabilistic failures and induced data variability, with performance metrics focusing on information availability, latency, and trustworthiness. Results demonstrated that using UAVs as routers increased network availability with a minimal latency penalty and communications satellite networks were best for long distance operations. Redundancy in the number of links between communication nodes helped mitigate cyber-caused link failures and add robustness in cases of induced data variability by an adversary. However, when failures were not independent, redundancy and UAV routing were detrimental in some cases to network performance. Sensitivity studies indicated that long cyber-caused downtimes and increasing failure dependencies resulted in build-ups of failures and caused significant degradations in network performance.

[Research and implementation of the TLS network transport security technology based on DICOM standard].

PubMed

Lu, Xiaoqi; Wang, Lei; Zhao, Jianfeng

2012-02-01

With the development of medical information, Picture Archiving and Communications System (PACS), Hospital Information System/Radiology Information System(HIS/RIS) and other medical information management system become popular and developed, and interoperability between these systems becomes more frequent. So, these enclosed systems will be open and regionalized by means of network, and this is inevitable. If the trend becomes true, the security of information transmission may be the first problem to be solved. Based on the need for network security, we investigated the Digital Imaging and Communications in Medicine (DICOM) Standard and Transport Layer Security (TLS) Protocol, and implemented the TLS transmission of the DICOM medical information with OpenSSL toolkit and DCMTK toolkit.

A CDMA system implementation with dimming control for visible light communication

NASA Astrophysics Data System (ADS)

Chen, Danyang; Wang, Jianping; Jin, Jianli; Lu, Huimin; Feng, Lifang

2018-04-01

Visible light communication (VLC), using solid-state lightings to transmit information, has become a complement technology to wireless radio communication. As a realistic multiple access scheme for VLC system, code division multiple access (CDMA) has attracted more and more attentions in recent years. In this paper, we address and implement an improved CDMA scheme for VLC system. The simulation results reveal that the improved CDMA scheme not only supports multi-users' transmission but also maintains dimming value at about 50% and enhances the system efficiency. It can also realize the flexible dimming control by adjusting some parameters of system structure, which rarely affects the system BER performance. A real-time experimental VLC system with improved CDMA scheme is performed based on field programmable gate array (FPGA), reaching a good BER performance.

Information and communication systems for the assistance of carers based on ACTION.

PubMed

Kraner, M; Emery, D; Cvetkovic, S R; Procter, P; Smythe, C

1999-01-01

Recent advances in telecommunication technologies allow the design of information and communication systems for people who are caring for others in the home as family members or as professionals in the health or community centres. The present paper analyses and classifies the information flow and maps it to an information life cycle, which governs the design of the deployed hardware, software and the data-structure. This is based on the initial findings of ACTION (assisting carers using telematics interventions to meet older persons' needs) a European Union funded project. The proposed information architecture discusses different designs such as centralized or decentralized Web and Client server solutions. A user interface is developed reflecting the special requirements of the targeted user group, which influences the functionality and design of the software, data architecture and the integrated communication system using video-conferencing. ACTION has engineered a system using plain Web technology based on HTML, extended with JavaScript and ActiveX and a software switch enabling the integration of different types of videoconferencing and other applications providing manufacturer independence.

Thought-based row-column scanning communication board for individuals with cerebral palsy.

PubMed

Scherer, Reinhold; Billinger, Martin; Wagner, Johanna; Schwarz, Andreas; Hettich, Dirk Tassilo; Bolinger, Elaina; Lloria Garcia, Mariano; Navarro, Juan; Müller-Putz, Gernot

2015-02-01

Impairment of an individual's ability to communicate is a major hurdle for active participation in education and social life. A lot of individuals with cerebral palsy (CP) have normal intelligence, however, due to their inability to communicate, they fall behind. Non-invasive electroencephalogram (EEG) based brain-computer interfaces (BCIs) have been proposed as potential assistive devices for individuals with CP. BCIs translate brain signals directly into action. Motor activity is no longer required. However, translation of EEG signals may be unreliable and requires months of training. Moreover, individuals with CP may exhibit high levels of spontaneous and uncontrolled movement, which has a large impact on EEG signal quality and results in incorrect translations. We introduce a novel thought-based row-column scanning communication board that was developed following user-centered design principles. Key features include an automatic online artifact reduction method and an evidence accumulation procedure for decision making. The latter allows robust decision making with unreliable BCI input. Fourteen users with CP participated in a supporting online study and helped to evaluate the performance of the developed system. Users were asked to select target items with the row-column scanning communication board. The results suggest that seven among eleven remaining users performed better than chance and were consequently able to communicate by using the developed system. Three users were excluded because of insufficient EEG signal quality. These results are very encouraging and represent a good foundation for the development of real-world BCI-based communication devices for users with CP. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Internet-Based System for Voice Communication With the ISS

NASA Technical Reports Server (NTRS)

Chamberlain, James; Myers, Gerry; Clem, David; Speir, Terri

2005-01-01

The Internet Voice Distribution System (IVoDS) is a voice-communication system that comprises mainly computer hardware and software. The IVoDS was developed to supplement and eventually replace the Enhanced Voice Distribution System (EVoDS), which, heretofore, has constituted the terrestrial subsystem of a system for voice communications among crewmembers of the International Space Station (ISS), workers at the Payloads Operations Center at Marshall Space Flight Center, principal investigators at diverse locations who are responsible for specific payloads, and others. The IVoDS utilizes a communication infrastructure of NASA and NASArelated intranets in addition to, as its name suggests, the Internet. Whereas the EVoDS utilizes traditional circuitswitched telephony, the IVoDS is a packet-data system that utilizes a voice over Internet protocol (VOIP). Relative to the EVoDS, the IVoDS offers advantages of greater flexibility and lower cost for expansion and reconfiguration. The IVoDS is an extended version of a commercial Internet-based voice conferencing system that enables each user to participate in only one conference at a time. In the IVoDS, a user can receive audio from as many as eight conferences simultaneously while sending audio to one of them. The IVoDS also incorporates administrative controls, beyond those of the commercial system, that provide greater security and control of the capabilities and authorizations for talking and listening afforded to each user.

Developing an Internet-based Communication System for Residency Training Programs

PubMed Central

Fortin, Auguste H; Luzzi, Kristina; Galaty, Leslie; Wong, Jeffrey G; Huot, Stephen J

2002-01-01

Administrative communication is increasingly challenging for residency programs as the number of training sites expands. The Internet provides a cost-effective opportunity to address these needs. Using the World Wide Web, we developed a single, reliable, accurate, and accessible source of administrative information for residents, faculty, and staff in a multisite internal medicine residency at reduced costs. Evaluation of the effectiveness of the website was determined by tracking website use, materials and personnel costs, and resident, staff, and faculty satisfaction. Office supply and personnel costs were reduced by 89% and personnel effort by 85%. All users were highly satisfied with the web communication tool and all reported increased knowledge of program information and a greater sense of “connectedness.” We conclude that an internet-based communication system that provides a single, reliable, accurate, and accessible source of information for residents, faculty, and staff can be developed with minimum resources and reduced costs. PMID:11972724

[Research on the High Efficiency Data Communication Repeater Based on STM32F103].

PubMed

Zhang, Yahui; Li, Zheng; Chen, Guangfei

2015-11-01

To improve the radio frequency (RF) transmission distance of the wireless terminal of the medical internet of things (LOT), to realize the real-time and efficient data communication, the intelligent relay system based on STM32F103 single chip microcomputer (SCM) is proposed. The system used nRF905 chip to achieve the collection, of medical and health information of patients in the 433 MHz band, used SCM to control the serial port to Wi-Fi module to transmit information from 433 MHz to 2.4 GHz wireless Wi-Fi band, and used table look-up algorithm of ready list to improve the efficiency of data communications. The design can realize real-time and efficient data communication. The relay which is easy to use with high practical value can extend the distance and mode of data transmission and achieve real-time transmission of data.

Strengthening of Indonesia school of management in the 21st century through the implementation of school management system based information technology and communications integrated

NASA Astrophysics Data System (ADS)

Setiawan, Wawan; Munir, Senen, Syamsul Hadi; Nugroho, Eddy Prasetyo; Wihardi, Yaya; Nugraha, Eki

2017-05-01

Indonesia strengthening school management through the implementation of School Management System Based Information Technology and Communications (SMS-ICT) is intended to improve the performance of schools to accommodate the complexities of management in a computerized system that is simple but comprehensive so that it aligns with the era of the 21st century. School Management System Based Information and Communication Technology-based standards developed 12 education, adapted from 8 national standards into the system components that support the characteristics of 21st century schools. Twelfth system components include curriculum, Personal Development, Recruitment of New Student Services and Student Development, Education Labor and Education, Infrastructure, Leadership, School Management, Financing, Evaluation, and Social Communications. Development of the system is done through the stages of systematically covering Need Assessment, System Design, System Development, Testing Limited, Reveiw and Improvement, Testing Expanded, Finalize, and Packaging. SMS-ICT has gained Copyright and had seminars both nationally and internationally, and have been published by national journals, and in a book chapter. SMS-ICT applied to several schools in districy/city of West Java is based on cooperation with the Education Department of West Java. Implementation of School Management System as strengthening school management Indonesia shows the essential matters of school management. SMS-ICT managed to bring changes not only bring substantial improvements to the school how it should be managed, but also change the mindset of school leaders and teachers in ways of thinking and acting more professional in carrying out their respective duties. SMS-ICT managed as a unified system of governance that is integrated schools overall strategic component in an integrated system that implements ICT that has the capacity to process data and information quickly, accurately and reliably. SMS-ICT as a mainstay to foster confidence that their school is a superior school that can be presented and demonstrated significantly. School leaders have the managerial instrument to control and develop all essential aspects in a comprehensive school. Empowering ICT appropriately and productively in school management processes, not only as a substitute for a typewriter and not only as a display.

Architecture Studies Done for High-Rate Duplex Direct Data Distribution (D4) Services

NASA Technical Reports Server (NTRS)

2002-01-01

A study was sponsored to investigate a set of end-to-end system concepts for implementing a high-rate duplex direct data distribution (D4) space-to-ground communications link. The NASA Glenn Research Center is investigating these systems (both commercial and Government) as a possible method of providing a D4 communications service between NASA spacecraft in low Earth orbit and the respective principal investigators using or monitoring instruments aboard these spacecraft. Candidate commercial services were assessed regarding their near-term potential to provide a D4 type of service. The candidates included K-band and V-band geostationary orbit and nongeostationary orbit satellite relay services and direct downlink (D3) services. Internet protocol (IP) networking technologies were evaluated to enable the user-directed distribution and delivery of science data. Four realistic, near-future concepts were analyzed: 1) A duplex direct link (uplink plus downlink communication paths) between a low-Earth-orbit spacecraft and a principal-investigator-based autonomous Earth station; 2) A space-based relay using a future K-band nongeosynchronous-orbit system to handle both the uplink and downlink communication paths; 3) A hybrid link using both direct and relay services to achieve full duplex capability; 4) A dual-mode concept consisting of both a duplex direct link and a space relay duplex link operating independently. The concepts were analyzed in terms of contact time between the NASA spacecraft and the communications service and the achievable data throughput. Throughput estimates for the D4 systems were based on the infusion of advanced communications technology products (single and multibeam K-band phased-arrays and digital modems) being developed by Glenn. Cost estimates were also performed using extrapolated information from both terrestrial and current satellite communications providers. The throughput and cost estimates were used to compare the concepts.

Evaluation of the communication quality of free-space laser communication based on the power-in-the-bucket method.

PubMed

Yin, Xianghui; Wang, Rui; Wang, Shaoxin; Wang, Yukun; Jin, Chengbin; Cao, Zhaoliang; Xuan, Li

2018-02-01

Atmospheric turbulence seriously affects the quality of free-space laser communication. The Strehl ratio (SR) is used to evaluate the effect of atmospheric turbulence on the receiving energy of free-space laser communication systems. However, the SR method does not consider the area of the laser-receiving end face. In this study, the power-in-the-bucket (PIB) method is demonstrated to accurately evaluate the effect of turbulence on the receiving energy. A theoretical equation is first obtained to calculate PIB. Simulated and experimental validations are then performed to verify the effectiveness of the theoretical equation. This work may provide effective guidance for the design and evaluation of free-space laser communication systems.

SMC: SCENIC Model Control

NASA Technical Reports Server (NTRS)

Srivastava, Priyaka; Kraus, Jeff; Murawski, Robert; Golden, Bertsel, Jr.

2015-01-01

NASAs Space Communications and Navigation (SCaN) program manages three active networks: the Near Earth Network, the Space Network, and the Deep Space Network. These networks simultaneously support NASA missions and provide communications services to customers worldwide. To efficiently manage these resources and their capabilities, a team of student interns at the NASA Glenn Research Center is developing a distributed system to model the SCaN networks. Once complete, the system shall provide a platform that enables users to perform capacity modeling of current and prospective missions with finer-grained control of information between several simulation and modeling tools. This will enable the SCaN program to access a holistic view of its networks and simulate the effects of modifications in order to provide NASA with decisional information. The development of this capacity modeling system is managed by NASAs Strategic Center for Education, Networking, Integration, and Communication (SCENIC). Three primary third-party software tools offer their unique abilities in different stages of the simulation process. MagicDraw provides UMLSysML modeling, AGIs Systems Tool Kit simulates the physical transmission parameters and de-conflicts scheduled communication, and Riverbed Modeler (formerly OPNET) simulates communication protocols and packet-based networking. SCENIC developers are building custom software extensions to integrate these components in an end-to-end space communications modeling platform. A central control module acts as the hub for report-based messaging between client wrappers. Backend databases provide information related to mission parameters and ground station configurations, while the end user defines scenario-specific attributes for the model. The eight SCENIC interns are working under the direction of their mentors to complete an initial version of this capacity modeling system during the summer of 2015. The intern team is composed of four students in Computer Science, two in Computer Engineering, one in Electrical Engineering, and one studying Space Systems Engineering.

Alternative Theoretical Bases for the Study of Human Communication: The Rules Perspective.

ERIC Educational Resources Information Center

Cushman, Donald P.

Three potentially useful perspectives for the scientific development of human communication theory are the law model, the systems approach, and the rules paradigm. It is the purpose of this paper to indicate the utility of the rules perspective. For the purposes of this analysis, human communication is viewed as the successful transfer of symbolic…

Phase-Quantized Block Noncoherent Communication

DTIC Science & Technology

2013-07-01

2828 IEEE TRANSACTIONS ON COMMUNICATIONS, VOL. 61, NO. 7, JULY 2013 Phase-Quantized Block Noncoherent Communication Jaspreet Singh and Upamanyu...in a carrier asynchronous system. Specifically, we consider transmission over the block noncoherent additive white Gaussian noise channel, and...block noncoherent channel. Several results, based on the symmetry inherent in the channel model, are provided to characterize this transition density

Design of a virtual reality based adaptive response technology for children with autism.

PubMed

Lahiri, Uttama; Bekele, Esubalew; Dohrmann, Elizabeth; Warren, Zachary; Sarkar, Nilanjan

2013-01-01

Children with autism spectrum disorder (ASD) demonstrate potent impairments in social communication skills including atypical viewing patterns during social interactions. Recently, several assistive technologies, particularly virtual reality (VR), have been investigated to address specific social deficits in this population. Some studies have coupled eye-gaze monitoring mechanisms to design intervention strategies. However, presently available systems are designed to primarily chain learning via aspects of one's performance only which affords restricted range of individualization. The presented work seeks to bridge this gap by developing a novel VR-based interactive system with Gaze-sensitive adaptive response technology that can seamlessly integrate VR-based tasks with eye-tracking techniques to intelligently facilitate engagement in tasks relevant to advancing social communication skills. Specifically, such a system is capable of objectively identifying and quantifying one's engagement level by measuring real-time viewing patterns, subtle changes in eye physiological responses, as well as performance metrics in order to adaptively respond in an individualized manner to foster improved social communication skills among the participants. The developed system was tested through a usability study with eight adolescents with ASD. The results indicate the potential of the system to promote improved social task performance along with socially-appropriate mechanisms during VR-based social conversation tasks.

Design of a Virtual Reality Based Adaptive Response Technology for Children With Autism

PubMed Central

Lahiri, Uttama; Bekele, Esubalew; Dohrmann, Elizabeth; Warren, Zachary; Sarkar, Nilanjan

2013-01-01

Children with autism spectrum disorder (ASD) demonstrate potent impairments in social communication skills including atypical viewing patterns during social interactions. Recently, several assistive technologies, particularly virtual reality (VR), have been investigated to address specific social deficits in this population. Some studies have coupled eye-gaze monitoring mechanisms to design intervention strategies. However, presently available systems are designed to primarily chain learning via aspects of one’s performance only which affords restricted range of individualization. The presented work seeks to bridge this gap by developing a novel VR-based interactive system with Gaze-sensitive adaptive response technology that can seamlessly integrate VR-based tasks with eye-tracking techniques to intelligently facilitate engagement in tasks relevant to advancing social communication skills. Specifically, such a system is capable of objectively identifying and quantifying one’s engagement level by measuring real-time viewing patterns, subtle changes in eye physiological responses, as well as performance metrics in order to adaptively respond in an individualized manner to foster improved social communication skills among the participants. The developed system was tested through a usability study with eight adolescents with ASD. The results indicate the potential of the system to promote improved social task performance along with socially-appropriate mechanisms during VR-based social conversation tasks. PMID:23033333

Piezo-Phototronic Effect Controlled Dual-Channel Visible light Communication (PVLC) Using InGaN/GaN Multiquantum Well Nanopillars.

PubMed

Du, Chunhua; Jiang, Chunyan; Zuo, Peng; Huang, Xin; Pu, Xiong; Zhao, Zhenfu; Zhou, Yongli; Li, Linxuan; Chen, Hong; Hu, Weiguo; Wang, Zhong Lin

2015-12-02

Visible light communication (VLC) simultaneously provides illumination and communication via light emitting diodes (LEDs). Keeping a low bit error rate is essential to communication quality, and holding a stable brightness level is pivotal for illumination function. For the first time, a piezo-phototronic effect controlled visible light communication (PVLC) system based on InGaN/GaN multiquantum wells nanopillars is demonstrated, in which the information is coded by mechanical straining. This approach of force coding is also instrumental to avoid LED blinks, which has less impact on illumination and is much safer to eyes than electrical on/off VLC. The two-channel transmission mode of the system here shows great superiority in error self-validation and error self-elimination in comparison to VLC. This two-channel PVLC system provides a suitable way to carry out noncontact, reliable communication under complex circumstances. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Via generalized function projective synchronization in nonlinear Schrödinger equation for secure communication

NASA Astrophysics Data System (ADS)

Zhao, L. W.; Du, J. G.; Yin, J. L.

2018-05-01

This paper proposes a novel secured communication scheme in a chaotic system by applying generalized function projective synchronization of the nonlinear Schrödinger equation. This phenomenal approach guarantees a secured and convenient communication. Our study applied the Melnikov theorem with an active control strategy to suppress chaos in the system. The transmitted information signal is modulated into the parameter of the nonlinear Schrödinger equation in the transmitter and it is assumed that the parameter of the receiver system is unknown. Based on the Lyapunov stability theory and the adaptive control technique, the controllers are designed to make two identical nonlinear Schrödinger equation with the unknown parameter asymptotically synchronized. The numerical simulation results of our study confirmed the validity, effectiveness and the feasibility of the proposed novel synchronization method and error estimate for a secure communication. The Chaos masking signals of the information communication scheme, further guaranteed a safer and secured information communicated via this approach.

Developing Low-Power Transceiver Technologies for In Situ Communication Applications

NASA Astrophysics Data System (ADS)

Lay, N.; Cheetham, C.; Mojaradi, H.; Neal, J.

2001-07-01

For future deep-space missions, significant reductions in the mass and power requirements for short-range telecommunication systems will be critical in enabling a wide variety of new mission concepts. These possibilities include penetrators, gliders, miniature rovers, balloons, and sensor networks. The recent development activity reported in this article has focused on the design of ultra-low-mass and -power transceiver systems and subsystems suitable for operation in a flight environment. Under these efforts, the basic functionality of the transceiver has been targeted towards a Mars microprobe communications scenario. However, the overall transceiver architecture is well suited to any short- or medium-range application where a remote probe will aperiodically communicate with a base station, possibly an orbiter, for the eventual purpose of relaying science information back to Earth. Additionally, elements of the radio architecture can be applied in situations involving surface-to-surface communications, thereby enabling different mission communications topologies. Through a system analysis of these channels, both the applicability and benefit of very low power communications will be quantitatively addressed.

Software-Implemented Fault Tolerance in Communications Systems

NASA Technical Reports Server (NTRS)

Gantenbein, Rex E.

1994-01-01

Software-implemented fault tolerance (SIFT) is used in many computer-based command, control, and communications (C(3)) systems to provide the nearly continuous availability that they require. In the communications subsystem of Space Station Alpha, SIFT algorithms are used to detect and recover from failures in the data and command link between the Station and its ground support. The paper presents a review of these algorithms and discusses how such techniques can be applied to similar systems found in applications such as manufacturing control, military communications, and programmable devices such as pacemakers. With support from the Tracking and Communication Division of NASA's Johnson Space Center, researchers at the University of Wyoming are developing a testbed for evaluating the effectiveness of these algorithms prior to their deployment. This testbed will be capable of simulating a variety of C(3) system failures and recording the response of the Space Station SIFT algorithms to these failures. The design of this testbed and the applicability of the approach in other environments is described.

Electro-mechanical probe positioning system for large volume plasma device

NASA Astrophysics Data System (ADS)

Sanyasi, A. K.; Sugandhi, R.; Srivastava, P. K.; Srivastav, Prabhakar; Awasthi, L. M.

2018-05-01

An automated electro-mechanical system for the positioning of plasma diagnostics has been designed and implemented in a Large Volume Plasma Device (LVPD). The system consists of 12 electro-mechanical assemblies, which are orchestrated using the Modbus communication protocol on 4-wire RS485 communications to meet the experimental requirements. Each assembly has a lead screw-based mechanical structure, Wilson feed-through-based vacuum interface, bipolar stepper motor, micro-controller-based stepper drive, and optical encoder for online positioning correction of probes. The novelty of the system lies in the orchestration of multiple drives on a single interface, fabrication and installation of the system for a large experimental device like the LVPD, in-house developed software, and adopted architectural practices. The paper discusses the design, description of hardware and software interfaces, and performance results in LVPD.

High Temperature Wireless Communication And Electronics For Harsh Environment Applications

NASA Technical Reports Server (NTRS)

Hunter, G. W.; Neudeck, P. G.; Beheim, G. M.; Ponchak, G. E.; Chen, L.-Y

2007-01-01

In order for future aerospace propulsion systems to meet the increasing requirements for decreased maintenance, improved capability, and increased safety, the inclusion of intelligence into the propulsion system design and operation becomes necessary. These propulsion systems will have to incorporate technology that will monitor propulsion component conditions, analyze the incoming data, and modify operating parameters to optimize propulsion system operations. This implies the development of sensors, actuators, and electronics, with associated packaging, that will be able to operate under the harsh environments present in an engine. However, given the harsh environments inherent in propulsion systems, the development of engine-compatible electronics and sensors is not straightforward. The ability of a sensor system to operate in a given environment often depends as much on the technologies supporting the sensor element as the element itself. If the supporting technology cannot handle the application, then no matter how good the sensor is itself, the sensor system will fail. An example is high temperature environments where supporting technologies are often not capable of operation in engine conditions. Further, for every sensor going into an engine environment, i.e., for every new piece of hardware that improves the in-situ intelligence of the components, communication wires almost always must follow. The communication wires may be within or between parts, or from the engine to the controller. As more hardware is added, more wires, weight, complexity, and potential for unreliability is also introduced. Thus, wireless communication combined with in-situ processing of data would significantly improve the ability to include sensors into high temperature systems and thus lead toward more intelligent engine systems. NASA Glenn Research Center (GRC) is presently leading the development of electronics, communication systems, and sensors capable of prolonged stable operation in harsh 500C environments. This has included world record operation of SiC-based transistor technology (including packaging) that has demonstrated continuous electrical operation at 500C for over 2000 hours. Based on SiC electronics, development of high temperature wireless communication has been on-going. This work has concentrated on maturing the SiC electronic devices for communication purposes as well as the passive components such as resistors and capacitors needed to enable a high temperature wireless system. The objective is to eliminate wires associated with high temperature sensors which add weight to a vehicle and can be a cause of sensor unreliability. This paper discusses the development of SiC based electronics and wireless communications technology for harsh environment applications such as propulsion health management systems and in Venus missions. A brief overview of the future directions in sensor technology is given including maturing of near-room temperature "Lick and Stick" leak sensor technology for possible implementation in the Crew Launch Vehicle program. Then an overview of high temperature electronics and the development of high temperature communication systems is presented. The maturity of related technologies such as sensor and packaging will also be discussed. It is concluded that a significant component of efforts to improve the intelligence of harsh environment operating systems is the development and implementation of high temperature wireless technology

Radiation-Hardened Electronics for Advanced Communications Systems

NASA Technical Reports Server (NTRS)

Whitaker, Sterling

2015-01-01

Novel approach enables high-speed special-purpose processors Advanced reconfigurable and reprogrammable communication systems will require sub-130-nanometer electronics. Legacy single event upset (SEU) radiation-tolerant circuits are ineffective at speeds greater than 125 megahertz. In Phase I of this project, ICs, LLC, demonstrated new base-level logic circuits that provide SEU immunity for sub-130-nanometer high-speed circuits. In Phase II, the company developed an innovative self-restoring logic (SRL) circuit and a system approach that provides high-speed, SEU-tolerant solutions that are effective for sub-130-nanometer electronics scalable to at least 22-nanometer processes. The SRL system can be used in the design of NASA's next-generation special-purpose processors, especially reconfigurable communication processors.

A new precoding scheme for spectral efficient optical OFDM systems

NASA Astrophysics Data System (ADS)

Hardan, Saad Mshhain; Bayat, Oguz; Abdulkafi, Ayad Atiyah

2018-07-01

Achieving high spectral efficiency is the key requirement of 5G and optical wireless communication systems and has recently attracted much attention, aiming to satisfy the ever increasing demand for high data rates in communications systems. In this paper, we propose a new precoding/decoding algorithm for spectral efficient optical orthogonal frequency division multiplexing (OFDM) scheme based visible light communication (VLC) systems. The proposed coded modulated optical (CMO) based OFDM system can be applied for both single input single output (SISO) and multiple input multiple-output (MIMO) architectures. Firstly, the real OFDM time domain signal is obtained through invoking the precoding/decoding algorithm without the Hermitian symmetry. After that, the positive signal is achieved either by adding a DC-bias or by using the spatial multiplexing technique. The proposed CMO-OFDM scheme efficiently improves the spectral efficiency of the VLC system as it does not require the Hermitian symmetry constraint to yield real signals. A comparison of the performance improvement of the proposed scheme with other OFDM approaches is also presented in this work. Simulation results show that the proposed CMO-OFDM scheme can not only enhance the spectral efficiency of OFDM-based VLC systems but also improve bit error rate (BER) performance compared with other optical OFDM schemes.

Integrating radiology information systems with healthcare delivery environments using DICOM and HL7 standards.

PubMed

Blazona, Bojan; Koncar, Miroslav

2006-01-01

Integration based on open standards, in order to achieve communication and information interoperability, is one of the key aspects of modern health care information systems. Interoperability presents data and communication layer interchange. In this context we identified the HL7 standard as the world's leading medical Information and communication technology (ICT) standard for the business layer in healthcare information systems and we tried to explore the ability to exchange clinical documents with minimal integrated healthcare information systems (IHCIS) change. We explored HL7 Clinical Document Architecture (CDA) abilities to achieve radiology information system integration (DICOM) to IHCIS (HL7). We introduced the use of WADO service interconnection to IHCIS and finally CDA rendering in widely used Internet explorers.

A Software Defined Radio Based Airplane Communication Navigation Simulation System

NASA Astrophysics Data System (ADS)

He, L.; Zhong, H. T.; Song, D.

2018-01-01

Radio communication and navigation system plays important role in ensuring the safety of civil airplane in flight. Function and performance should be tested before these systems are installed on-board. Conventionally, a set of transmitter and receiver are needed for each system, thus all the equipment occupy a lot of space and are high cost. In this paper, software defined radio technology is applied to design a common hardware communication and navigation ground simulation system, which can host multiple airplane systems with different operating frequency, such as HF, VHF, VOR, ILS, ADF, etc. We use a broadband analog frontend hardware platform, universal software radio peripheral (USRP), to transmit/receive signal of different frequency band. Software is compiled by LabVIEW on computer, which interfaces with USRP through Ethernet, and is responsible for communication and navigation signal processing and system control. An integrated testing system is established to perform functional test and performance verification of the simulation signal, which demonstrate the feasibility of our design. The system is a low-cost and common hardware platform for multiple airplane systems, which provide helpful reference for integrated avionics design.

History and structures of telecommunication in pathology, focusing on open access platforms.

PubMed

Kayser, Klaus; Borkenfeld, Stephan; Djenouni, Amina; Kayser, Gian

2011-11-07

Telecommunication has matured to a broadly applied tool in diagnostic pathology. Contemporary with the development of fast electronic communication lines (Integrated digital network services (ISDN), broad band connections, and fibre optics, as well as the digital imaging technology (digital camera), telecommunication in tissue--based diagnosis (telepathology) has matured. Open access (internet) and server--based communication have induced the development of specific medical information platforms, such as iPATH, UICC-TPCC (telepathology consultation centre of the Union International against Cancer), or the Armed Forces Institute of Pathology (AFIP) teleconsultation system. They have been closed, and are subject to be replaced by specific open access forums (Medical Electronic Expert Communication System (MECES) with embedded virtual slide (VS) technology). MECES uses php language, data base driven mySqL architecture, X/L-AMPP infrastructure, and browser friendly W3C conform standards. The server--based medical communication systems (AFIP, iPATH, UICC-TPCC) have been reported to be a useful and easy to handle tool for expert consultation. Correct sampling and evaluation of transmitted still images by experts reported revealed no or only minor differences to the original images and good practice of the involved experts. β tests with the new generation medical expert consultation systems (MECES) revealed superior results in terms of performance, still image viewing, and system handling, especially as this is closely related to the use of so--called social forums (facebook, youtube, etc.). In addition to the acknowledged advantages of the former established systems (assistance of pathologists working in developing countries, diagnosis confirmation, international information exchange, etc.), the new generation offers additional benefits such as acoustic information transfer, assistance in image screening, VS technology, and teaching in diagnostic sampling, judgement, and verification.

47 CFR 90.691 - Emission mask requirements for EA-based systems.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 5 2010-10-01 2010-10-01 false Emission mask requirements for EA-based systems. 90.691 Section 90.691 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND... of Ea-Based Smr Systems in the 809-824/851-869 Mhz Band § 90.691 Emission mask requirements for EA...

Bio-Terrorism: Steps to Effective Public Health Risk Communication and Fear Management

DTIC Science & Technology

2004-06-01

outline the challenges of communicating risk prior to, during and following a bio-terrorism event as well as the relationship between the content of...particularly challenging for a system based on thorough research and data analysis. Risk communication in a bio-terrorism event will involve...Ultimately, the Anthrax events confirmed the difficulty in communicating risk when scientific data is not available. Adding to the challenges imposed by an

A mobile robots experimental environment with event-based wireless communication.

PubMed

Guinaldo, María; Fábregas, Ernesto; Farias, Gonzalo; Dormido-Canto, Sebastián; Chaos, Dictino; Sánchez, José; Dormido, Sebastián

2013-07-22

An experimental platform to communicate between a set of mobile robots through a wireless network has been developed. The mobile robots get their position through a camera which performs as sensor. The video images are processed in a PC and a Waspmote card sends the corresponding position to each robot using the ZigBee standard. A distributed control algorithm based on event-triggered communications has been designed and implemented to bring the robots into the desired formation. Each robot communicates to its neighbors only at event times. Furthermore, a simulation tool has been developed to design and perform experiments with the system. An example of usage is presented.

Communication scheme based on evolutionary spatial 2×2 games

NASA Astrophysics Data System (ADS)

Ziaukas, Pranas; Ragulskis, Tautvydas; Ragulskis, Minvydas

2014-06-01

A visual communication scheme based on evolutionary spatial 2×2 games is proposed in this paper. Self-organizing patterns induced by complex interactions between competing individuals are exploited for hiding and transmitting secret visual information. Properties of the proposed communication scheme are discussed in details. It is shown that the hiding capacity of the system (the minimum size of the detectable primitives and the minimum distance between two primitives) is sufficient for the effective transmission of digital dichotomous images. Also, it is demonstrated that the proposed communication scheme is resilient to time backwards, plain image attacks and is highly sensitive to perturbations of private and public keys. Several computational experiments are used to demonstrate the effectiveness of the proposed communication scheme.

Novel Web-based Education Platforms for Information Communication utilizing Gamification, Virtual and Immersive Reality

NASA Astrophysics Data System (ADS)

Demir, I.

2015-12-01

Recent developments in internet technologies make it possible to manage and visualize large data on the web. Novel visualization techniques and interactive user interfaces allow users to create realistic environments, and interact with data to gain insight from simulations and environmental observations. This presentation showcase information communication interfaces, games, and virtual and immersive reality applications for supporting teaching and learning of concepts in atmospheric and hydrological sciences. The information communication platforms utilizes latest web technologies and allow accessing and visualizing large scale data on the web. The simulation system is a web-based 3D interactive learning environment for teaching hydrological and atmospheric processes and concepts. The simulation systems provides a visually striking platform with realistic terrain and weather information, and water simulation. The web-based simulation system provides an environment for students to learn about the earth science processes, and effects of development and human activity on the terrain. Users can access the system in three visualization modes including virtual reality, augmented reality, and immersive reality using heads-up display. The system provides various scenarios customized to fit the age and education level of various users.

Web-Based Evaluation System for Learning Management Systems

ERIC Educational Resources Information Center

Momani, Alaa

2010-01-01

E-learning systems have become an issue in recent years. A learning management system (LMS) is an electronic environment helps the educational society to communicate, exchange information, manage, and schedule the learning process. This study has provided a web-based evaluation system that may help the users to choose the convenient system…

47 CFR 90.656 - Responsibilities of base station licensees of Specialized Mobile Radio systems.

Code of Federal Regulations, 2011 CFR

2011-10-01

... operate mobile units on a particular Specialized Mobile Radio system will be licensed to that system. A... Specialized Mobile Radio systems. 90.656 Section 90.656 Telecommunication FEDERAL COMMUNICATIONS COMMISSION... Bands § 90.656 Responsibilities of base station licensees of Specialized Mobile Radio systems. (a) The...

10 m/25 Gbps LiFi transmission system based on a two-stage injection-locked 680 nm VCSEL transmitter.

PubMed

Lu, Hai-Han; Li, Chung-Yi; Chu, Chien-An; Lu, Ting-Chien; Chen, Bo-Rui; Wu, Chang-Jen; Lin, Dai-Hua

2015-10-01

A 10  m/25  Gbps light-based WiFi (LiFi) transmission system based on a two-stage injection-locked 680 nm vertical-cavity surface-emitting laser (VCSEL) transmitter is proposed. A LiFi transmission system with a data rate of 25 Gbps is experimentally demonstrated over a 10 m free-space link. To the best of our knowledge, it is the first time a two-stage injection-locked 680 nm VCSEL transmitter in a 10  m/25  Gbps LiFi transmission system has been employed. Impressive bit error rate performance and a clear eye diagram are achieved in the proposed systems. Such a 10  m/25  Gbps LiFi transmission system provides the advantage of a communication link for higher data rates that could accelerate the deployment of visible laser light communication.