Distributed reservation control protocols for random access broadcasting channels

NASA Technical Reports Server (NTRS)

Greene, E. P.; Ephremides, A.

1981-01-01

Attention is given to a communication network consisting of an arbitrary number of nodes which can communicate with each other via a time-division multiple access (TDMA) broadcast channel. The reported investigation is concerned with the development of efficient distributed multiple access protocols for traffic consisting primarily of single packet messages in a datagram mode of operation. The motivation for the design of the protocols came from the consideration of efficient multiple access utilization of moderate to high bandwidth (4-40 Mbit/s capacity) communication satellite channels used for the transmission of short (1000-10,000 bits) fixed length packets. Under these circumstances, the ratio of roundtrip propagation time to packet transmission time is between 100 to 10,000. It is shown how a TDMA channel can be adaptively shared by datagram traffic and constant bandwidth users such as in digital voice applications. The distributed reservation control protocols described are a hybrid between contention and reservation protocols.

Some Protocols For Optical-Fiber Digital Communications

NASA Technical Reports Server (NTRS)

Yeh, Cavour; Gerla, Mario

1989-01-01

One works best in heavy traffic, another, in light traffic. Three protocols proposed for digital communications among stations connected by passive taps to pair of uni-directional optical-fiber buses. Mediate round-robin, bounded-delay access to buses by all stations and particularly suited to fast transmission. Partly because transmission medium passive (no relay stations) and partly because protocols distribute control of network among all stations with provision for addition and deletion of stations (no control stations), communication network able to resist and recover from failures. Implicit token propagates in one direction on one bus and in opposite direction on other bus, minimizing interval of silence between end of one round and beginning of next.

Energy Efficient Medium Access Control Protocol for Clustered Wireless Sensor Networks with Adaptive Cross-Layer Scheduling.

PubMed

Sefuba, Maria; Walingo, Tom; Takawira, Fambirai

2015-09-18

This paper presents an Energy Efficient Medium Access Control (MAC) protocol for clustered wireless sensor networks that aims to improve energy efficiency and delay performance. The proposed protocol employs an adaptive cross-layer intra-cluster scheduling and an inter-cluster relay selection diversity. The scheduling is based on available data packets and remaining energy level of the source node (SN). This helps to minimize idle listening on nodes without data to transmit as well as reducing control packet overhead. The relay selection diversity is carried out between clusters, by the cluster head (CH), and the base station (BS). The diversity helps to improve network reliability and prolong the network lifetime. Relay selection is determined based on the communication distance, the remaining energy and the channel quality indicator (CQI) for the relay cluster head (RCH). An analytical framework for energy consumption and transmission delay for the proposed MAC protocol is presented in this work. The performance of the proposed MAC protocol is evaluated based on transmission delay, energy consumption, and network lifetime. The results obtained indicate that the proposed MAC protocol provides improved performance than traditional cluster based MAC protocols.

Energy Efficient Medium Access Control Protocol for Clustered Wireless Sensor Networks with Adaptive Cross-Layer Scheduling

PubMed Central

Sefuba, Maria; Walingo, Tom; Takawira, Fambirai

2015-01-01

This paper presents an Energy Efficient Medium Access Control (MAC) protocol for clustered wireless sensor networks that aims to improve energy efficiency and delay performance. The proposed protocol employs an adaptive cross-layer intra-cluster scheduling and an inter-cluster relay selection diversity. The scheduling is based on available data packets and remaining energy level of the source node (SN). This helps to minimize idle listening on nodes without data to transmit as well as reducing control packet overhead. The relay selection diversity is carried out between clusters, by the cluster head (CH), and the base station (BS). The diversity helps to improve network reliability and prolong the network lifetime. Relay selection is determined based on the communication distance, the remaining energy and the channel quality indicator (CQI) for the relay cluster head (RCH). An analytical framework for energy consumption and transmission delay for the proposed MAC protocol is presented in this work. The performance of the proposed MAC protocol is evaluated based on transmission delay, energy consumption, and network lifetime. The results obtained indicate that the proposed MAC protocol provides improved performance than traditional cluster based MAC protocols. PMID:26393608

Bidirectional and Asymmetric Controlled Quantum Information Transmission via Five-qubit Brown State

NASA Astrophysics Data System (ADS)

Fang, Sheng-hui; Jiang, Min

2017-05-01

We put forward a new protocol of deterministic controlled bidirectional quantum information transmission, using a five-qubit Brown state. That is to say Alice wants to teleport an arbitrary single-qubit state to Bob and Bob wants to remotely prepare a known state for Alice via the control of the supervisor Charlie. In terms of physical implementations, only a CNOT gate, one Bell-state measurement and one qubit measurement are used in our protocol. Compared with previous study for solely bidirectional quantum teleportation and solely bidirectional remote state preparation schemes, our protocol is a kind of hybrid approach of information communication which makes the quantum channel multipurpose, i.e., no matter whether the transmitted state is known or unknown, the state information can be transmitted with each other via a five-qubit Brown state under the control of the third party as a supervisor.

Energy Consumption Research of Mobile Data Collection Protocol for Underwater Nodes Using an USV.

PubMed

Lv, Zhichao; Zhang, Jie; Jin, Jiucai; Li, Qi; Gao, Baoru

2018-04-16

The Unmanned Surface Vehicle (USV) integrated with an acoustic modem is a novel mobile vehicle for data collection, which has an advantage in terms of mobility, efficiency, and collection cost. In the scenario of data collection, the USV is controlled autonomously along the planning trajectory and the data of underwater nodes are dynamically collected. In order to improve the efficiency of data collection and extend the life of the underwater nodes, a mobile data collection protocol for underwater nodes using the USV was proposed. In the protocol, the stop-and-wait ARQ transmission mechanism is adopted, where the duty cycle is designed considering the ratio between the sleep mode and the detection mode, and the transmission ratio is defined by the duty cycle, wake-up signal cycles, and USV’s speed. According to protocol, the evaluation index for energy consumption is constructed based on the duty cycle and the transmission ratio. The energy consumption of the protocol is simulated and analyzed using the mobile communication experiment data of USV, taking into consideration USV’s speed, data sequence length, and duty cycle. Optimized protocol parameters are identified, which in turn denotes the proposed protocol’s feasibility and effectiveness.

SACFIR: SDN-Based Application-Aware Centralized Adaptive Flow Iterative Reconfiguring Routing Protocol for WSNs.

PubMed

Aslam, Muhammad; Hu, Xiaopeng; Wang, Fan

2017-12-13

Smart reconfiguration of a dynamic networking environment is offered by the central control of Software-Defined Networking (SDN). Centralized SDN-based management architectures are capable of retrieving global topology intelligence and decoupling the forwarding plane from the control plane. Routing protocols developed for conventional Wireless Sensor Networks (WSNs) utilize limited iterative reconfiguration methods to optimize environmental reporting. However, the challenging networking scenarios of WSNs involve a performance overhead due to constant periodic iterative reconfigurations. In this paper, we propose the SDN-based Application-aware Centralized adaptive Flow Iterative Reconfiguring (SACFIR) routing protocol with the centralized SDN iterative solver controller to maintain the load-balancing between flow reconfigurations and flow allocation cost. The proposed SACFIR's routing protocol offers a unique iterative path-selection algorithm, which initially computes suitable clustering based on residual resources at the control layer and then implements application-aware threshold-based multi-hop report transmissions on the forwarding plane. The operation of the SACFIR algorithm is centrally supervised by the SDN controller residing at the Base Station (BS). This paper extends SACFIR to SDN-based Application-aware Main-value Centralized adaptive Flow Iterative Reconfiguring (SAMCFIR) to establish both proactive and reactive reporting. The SAMCFIR transmission phase enables sensor nodes to trigger direct transmissions for main-value reports, while in the case of SACFIR, all reports follow computed routes. Our SDN-enabled proposed models adjust the reconfiguration period according to the traffic burden on sensor nodes, which results in heterogeneity awareness, load-balancing and application-specific reconfigurations of WSNs. Extensive experimental simulation-based results show that SACFIR and SAMCFIR yield the maximum scalability, network lifetime and stability period when compared to existing routing protocols.

SACFIR: SDN-Based Application-Aware Centralized Adaptive Flow Iterative Reconfiguring Routing Protocol for WSNs

PubMed Central

Hu, Xiaopeng; Wang, Fan

2017-01-01

Smart reconfiguration of a dynamic networking environment is offered by the central control of Software-Defined Networking (SDN). Centralized SDN-based management architectures are capable of retrieving global topology intelligence and decoupling the forwarding plane from the control plane. Routing protocols developed for conventional Wireless Sensor Networks (WSNs) utilize limited iterative reconfiguration methods to optimize environmental reporting. However, the challenging networking scenarios of WSNs involve a performance overhead due to constant periodic iterative reconfigurations. In this paper, we propose the SDN-based Application-aware Centralized adaptive Flow Iterative Reconfiguring (SACFIR) routing protocol with the centralized SDN iterative solver controller to maintain the load-balancing between flow reconfigurations and flow allocation cost. The proposed SACFIR’s routing protocol offers a unique iterative path-selection algorithm, which initially computes suitable clustering based on residual resources at the control layer and then implements application-aware threshold-based multi-hop report transmissions on the forwarding plane. The operation of the SACFIR algorithm is centrally supervised by the SDN controller residing at the Base Station (BS). This paper extends SACFIR to SDN-based Application-aware Main-value Centralized adaptive Flow Iterative Reconfiguring (SAMCFIR) to establish both proactive and reactive reporting. The SAMCFIR transmission phase enables sensor nodes to trigger direct transmissions for main-value reports, while in the case of SACFIR, all reports follow computed routes. Our SDN-enabled proposed models adjust the reconfiguration period according to the traffic burden on sensor nodes, which results in heterogeneity awareness, load-balancing and application-specific reconfigurations of WSNs. Extensive experimental simulation-based results show that SACFIR and SAMCFIR yield the maximum scalability, network lifetime and stability period when compared to existing routing protocols. PMID:29236031

Dynamical jumping real-time fault-tolerant routing protocol for wireless sensor networks.

PubMed

Wu, Guowei; Lin, Chi; Xia, Feng; Yao, Lin; Zhang, He; Liu, Bing

2010-01-01

In time-critical wireless sensor network (WSN) applications, a high degree of reliability is commonly required. A dynamical jumping real-time fault-tolerant routing protocol (DMRF) is proposed in this paper. Each node utilizes the remaining transmission time of the data packets and the state of the forwarding candidate node set to dynamically choose the next hop. Once node failure, network congestion or void region occurs, the transmission mode will switch to jumping transmission mode, which can reduce the transmission time delay, guaranteeing the data packets to be sent to the destination node within the specified time limit. By using feedback mechanism, each node dynamically adjusts the jumping probabilities to increase the ratio of successful transmission. Simulation results show that DMRF can not only efficiently reduce the effects of failure nodes, congestion and void region, but also yield higher ratio of successful transmission, smaller transmission delay and reduced number of control packets.

High-Bandwidth Tactical-Network Data Analysis in a High-Performance-Computing (HPC) Environment: Transport Protocol (Transmission Control Protocol/User Datagram Protocol [TCP/UDP]) Analysis

DTIC Science & Technology

2015-09-01

the network Mac8 Medium Access Control ( Mac ) (Ethernet) address observed as destination for outgoing packets subsessionid8 Zero-based index of...15. SUBJECT TERMS tactical networks, data reduction, high-performance computing, data analysis, big data 16. SECURITY CLASSIFICATION OF: 17...Integer index of row cts_deid Device (instrument) Identifier where observation took place cts_collpt Collection point or logical observation point on

Performance comparison of token ring protocols for hard-real-time communication

NASA Technical Reports Server (NTRS)

Kamat, Sanjay; Zhao, Wei

1992-01-01

The ability to guarantee the deadlines of synchronous messages while maintaining a good aggregate throughput is an important consideration in the design of distributed real-time systems. In this paper, we study two token ring protocols, the priority driven protocol and the timed token protocol, for their suitability for hard real-time systems. Both these protocols use a token to control access to the transmission medium. In a priority driven protocol, messages are assigned priorities and the protocol ensures that messages are transmitted in the order of their priorities. Timed token protocols do not provide for priority arbitration but ensure that the maximum access delay for a station is bounded. For both protocols, we first derive the schedulability conditions under which the transmission deadlines of a given set of synchronous messages can be guaranteed. Subsequently, we use these schedulability conditions to quantitatively compare the average case behavior of the protocols. This comparison demonstrates that each of the protocols has its domain of superior performance and neither dominates the other for the entire range of operating conditions.

Continuous-variable quantum key distribution in uniform fast-fading channels

NASA Astrophysics Data System (ADS)

Papanastasiou, Panagiotis; Weedbrook, Christian; Pirandola, Stefano

2018-03-01

We investigate the performance of several continuous-variable quantum key distribution protocols in the presence of uniform fading channels. These are lossy channels whose transmissivity changes according to a uniform probability distribution. We assume the worst-case scenario where an eavesdropper induces a fast-fading process, where she chooses the instantaneous transmissivity while the remote parties may only detect the mean statistical effect. We analyze coherent-state protocols in various configurations, including the one-way switching protocol in reverse reconciliation, the measurement-device-independent protocol in the symmetric configuration, and its extension to a three-party network. We show that, regardless of the advantage given to the eavesdropper (control of the fading), these protocols can still achieve high rates under realistic attacks, within reasonable values for the variance of the probability distribution associated with the fading process.

Low-cost Cognitive Electronics Technology for Enhanced Communications and Situational Awareness for Networks of Small Unmanned Aerial Vehicles (UAV)

DTIC Science & Technology

2013-03-01

series of checkpoints in a complex route network,” while observing standard traffic etiquette and regulations [17]. The rules for the 2012 RoboCup...structure or protocols above the PHY. To support AVEP operation, we developed a packet structure based on the transmission control protocol (TCP...Control Protocol .” 1981. [37] F. Ge, Q. Chen, Y. Wang, C. W. Bostian, T. W. Rondeau, and B. Le, “Cognitive radio: from spectrum sharing to adaptive

Data transmission optical link for RF-GUN project

NASA Astrophysics Data System (ADS)

Olowski, Krzysztof; Zielinski, Jerzy; Jalmuzna, Wojciech; Pozniak, Krzysztof; Romaniuk, Ryszard

2005-09-01

Today, the fast optical data transmission is one of the fundamentals of modern distributed control systems. The fibers are widely use as multi-gigabit data stream medium. For a short range transmission, the multimode fibers are in common use. The data rate for this kind of transmission exceeds 10 Gbps for 10 Gigabit Ethernet and 10G Fibre Channel protocols. The Field Programmable Gate Arrays are one of the opportunities of managing the optical transmission. This article is concerning a synchronous optical transmission system via a multimode fiber. The transmission is controlled by the FPGA of two manufacturers: Xilinx and Altera. This paper contains the newest technology overview and market device parameters. It also describes a board for the optical transmission, technical details of the transmission and optical transmission results.

Multi-protocol header generation system

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

Roberts, David A.; Ignatowski, Michael; Jayasena, Nuwan

A communication device includes a data source that generates data for transmission over a bus, and a data encoder that receives and encodes outgoing data. An encoder system receives outgoing data from a data source and stores the outgoing data in a first queue. An encoder encodes outgoing data with a header type that is based upon a header type indication from a controller and stores the encoded data that may be a packet or a data word with at least one layered header in a second queue for transmission. The device is configured to receive at a payload extractor,more » a packet protocol change command from the controller and to remove the encoded data and to re-encode the data to create a re-encoded data packet and placing the re-encoded data packet in the second queue for transmission.« less

Intranets: Just Another Bandwagon?

ERIC Educational Resources Information Center

Lynch, Gary

1997-01-01

Discusses intranets--the deployment and use of Internet technologies such as the World Wide Web, electronic mail, and Transmission Control Protocol/Internet Protocol (TCP/IP) on a closed network. Considers the "hype," benefits, standards, implementation, and problems of intranets, and concludes that while intranets can be beneficial,…

Internet and Intranet Use with a PC: Effects of Adapter Cards, Windows Versions and TCP/IP Software on Networking Performance.

ERIC Educational Resources Information Center

Nieuwenhuysen, Paul

1997-01-01

Explores data transfer speeds obtained with various combinations of hardware and software components through a study of access to the Internet from a notebook computer connected to a local area network based on Ethernet and TCP/IP (transmission control protocol/Internet protocol) network protocols. Upgrading is recommended for higher transfer…

SVANET: A smart vehicular ad hoc network for efficient data transmission with wireless sensors.

PubMed

Sahoo, Prasan Kumar; Chiang, Ming-Jer; Wu, Shih-Lin

2014-11-25

Wireless sensors can sense any event, such as accidents, as well as icy roads, and can forward the rescue/warning messages through intermediate vehicles for any necessary help. In this paper, we propose a smart vehicular ad hoc network (SVANET) architecture that uses wireless sensors to detect events and vehicles to transmit the safety and non-safety messages efficiently by using different service channels and one control channel with different priorities. We have developed a data transmission protocol for the vehicles in the highway, in which data can be forwarded with the help of vehicles if they are connected with each other or data can be forwarded with the help of nearby wireless sensors. Our data transmission protocol is designed to increase the driving safety, to prevent accidents and to utilize channels efficiently by adjusting the control and service channel time intervals dynamically. Besides, our protocol can transmit information to vehicles in advance, so that drivers can decide an alternate route in case of traffic congestion. For various data sharing, we design a method that can select a few leader nodes among vehicles running along a highway to broadcast data efficiently. Simulation results show that our protocol can outperform the existing standard in terms of the end to end packet delivery ratio and latency.

SVANET: A Smart Vehicular Ad Hoc Network for Efficient Data Transmission with Wireless Sensors

PubMed Central

Sahoo, Prasan Kumar; Chiang, Ming-Jer; Wu, Shih-Lin

2014-01-01

Wireless sensors can sense any event, such as accidents, as well as icy roads, and can forward the rescue/warning messages through intermediate vehicles for any necessary help. In this paper, we propose a smart vehicular ad hoc network (SVANET) architecture that uses wireless sensors to detect events and vehicles to transmit the safety and non-safety messages efficiently by using different service channels and one control channel with different priorities. We have developed a data transmission protocol for the vehicles in the highway, in which data can be forwarded with the help of vehicles if they are connected with each other or data can be forwarded with the help of nearby wireless sensors. Our data transmission protocol is designed to increase the driving safety, to prevent accidents and to utilize channels efficiently by adjusting the control and service channel time intervals dynamically. Besides, our protocol can transmit information to vehicles in advance, so that drivers can decide an alternate route in case of traffic congestion. For various data sharing, we design a method that can select a few leader nodes among vehicles running along a highway to broadcast data efficiently. Simulation results show that our protocol can outperform the existing standard in terms of the end to end packet delivery ratio and latency. PMID:25429409

Running TCP/IP over ATM Networks.

ERIC Educational Resources Information Center

Witt, Michael

1995-01-01

Discusses Internet protocol (IP) and subnets and describes how IP may operate over asynchronous transfer mode (ATM). Topics include TCP (transmission control protocol), ATM cells and adaptation layers, a basic architectural model for IP over ATM, address resolution, mapping IP to a subnet technology, and connection management strategy. (LRW)

Bidirectional Controlled Quantum Information Transmission by Using a Five-Qubit Cluster State

NASA Astrophysics Data System (ADS)

Sang, Zhi-wen

2017-11-01

We demonstrate that an entangled five-qubit cluster state can be used to realize the deterministic bidirectional controlled quantum information transmission by performing only Bell-state measurement and single-qubit measurements. In our protocol, Alice can teleport an arbitrary unknown single-qubit state to Bob and at the same time Bob can remotely prepare an arbitrary known single-qubit state for Alice via the control of the supervisor Charlie.

Telemetry Standards, RCC Standard 106-17. Chapter 21. Telemetry Network Standard Introduction

DTIC Science & Technology

2017-07-01

Critical RF radio frequency RFC Request for Comment SNMP Simple Network Management Protocol TA test article TCP Transmission Control Protocol...chapters might be of most interest for a particular reader. In order to guide the reader toward the chapters of further interest , the applicable... Simple Network Management Protocol (SNMP) to pass management information through the system. The SNMP management information bases (MIBs) provide

Securing TCP/IP and Dial-up Access to Administrative Data.

ERIC Educational Resources Information Center

Conrad, L. Dean

1992-01-01

This article describes Arizona State University's solution to security risk inherent in general access systems such as TCP/IP (Transmission Control Protocol/INTERNET Protocol). Advantages and disadvantages of various options are compared, and the process of selecting a log-on authentication approach involving generation of a different password at…

The Internet and Education: Some Lessons on Privacy and Pitfalls.

ERIC Educational Resources Information Center

Descy, Don E.

1997-01-01

Most users have misconceptions about how the Internet works. Provides a brief history of the Internet and Transmission Control Protocol/Internet Protocol (TCP/IP); discusses electronic mail, privacy, and voluntary and involuntary information gathering; and contrasts the Internet and libraries, focusing on the Internet's lack of consistent…

NASA STI Program Coordinating Council Twelfth Meeting: Standards

NASA Technical Reports Server (NTRS)

1994-01-01

The theme of this NASA Scientific and Technical Information Program Coordinating Council Meeting was standards and their formation and application. Topics covered included scientific and technical information architecture, the Open Systems Interconnection Transmission Control Protocol/Internet Protocol, Machine-Readable Cataloging (MARC) open system environment procurement, and the Government Information Locator Service.

Flight related tuberculosis contact investigations in the United States: comparative risk and economic analysis of alternate protocols.

PubMed

Marienau, Karen J; Cramer, Elaine H; Coleman, Margaret S; Marano, Nina; Cetron, Martin S

2014-01-01

In-flight transmission risk of Mycobacterium tuberculosis is not well defined, although studies suggest it is low. The impact of flight-related tuberculosis (TB) contact investigations (TBCIs) on TB prevention and control is not well established, and they compete for resources with activities with established benefits. We sought to determine the risks and cost-benefits of using more restrictive criteria in comparison to the Centers for Disease Control and Prevention (CDC) 2008 protocol for TBCIs. The risk-benefits of a modified CDC protocol were analyzed in comparison to the 2008 CDC protocol using data from flight-related TBCIs conducted in the United States from 2007 through 2009. We predicted the numbers and characteristics of case-travelers that would be identified using each protocol's criteria, and results of the associated passenger-contacts' TB screening tests. The economic analysis compared the costs of TBCIs to avoided costs of TB treatment and mortality using a Return on Investment model. The estimated in-flight transmission risk using a modified CDC protocol was 1.4%-19% versus 1.1%-24% for the 2008 protocol. Numbers of TBCIs and immediate costs to health departments were reduced by half. Long-term cost-benefits were comparable. CDC's modified protocol appears to be a feasible alternative that will conserve public health resources without jeopardizing the public's health. Published by Elsevier Ltd.

Design and Development of Layered Security: Future Enhancements and Directions in Transmission

PubMed Central

Shahzad, Aamir; Lee, Malrey; Kim, Suntae; Kim, Kangmin; Choi, Jae-Young; Cho, Younghwa; Lee, Keun-Kwang

2016-01-01

Today, security is a prominent issue when any type of communication is being undertaken. Like traditional networks, supervisory control and data acquisition (SCADA) systems suffer from a number of vulnerabilities. Numerous end-to-end security mechanisms have been proposed for the resolution of SCADA-system security issues, but due to insecure real-time protocol use and the reliance upon open protocols during Internet-based communication, these SCADA systems can still be compromised by security challenges. This study reviews the security challenges and issues that are commonly raised during SCADA/protocol transmissions and proposes a secure distributed-network protocol version 3 (DNP3) design, and the implementation of the security solution using a cryptography mechanism. Due to the insecurities found within SCADA protocols, the new development consists of a DNP3 protocol that has been designed as a part of the SCADA system, and the cryptographically derived security is deployed within the application layer as a part of the DNP3 stack. PMID:26751443

Design and Development of Layered Security: Future Enhancements and Directions in Transmission.

PubMed

Shahzad, Aamir; Lee, Malrey; Kim, Suntae; Kim, Kangmin; Choi, Jae-Young; Cho, Younghwa; Lee, Keun-Kwang

2016-01-06

Today, security is a prominent issue when any type of communication is being undertaken. Like traditional networks, supervisory control and data acquisition (SCADA) systems suffer from a number of vulnerabilities. Numerous end-to-end security mechanisms have been proposed for the resolution of SCADA-system security issues, but due to insecure real-time protocol use and the reliance upon open protocols during Internet-based communication, these SCADA systems can still be compromised by security challenges. This study reviews the security challenges and issues that are commonly raised during SCADA/protocol transmissions and proposes a secure distributed-network protocol version 3 (DNP3) design, and the implementation of the security solution using a cryptography mechanism. Due to the insecurities found within SCADA protocols, the new development consists of a DNP3 protocol that has been designed as a part of the SCADA system, and the cryptographically derived security is deployed within the application layer as a part of the DNP3 stack.

Intelligent Local Avoided Collision (iLAC) MAC Protocol for Very High Speed Wireless Network

NASA Astrophysics Data System (ADS)

Hieu, Dinh Chi; Masuda, Akeo; Rabarijaona, Verotiana Hanitriniala; Shimamoto, Shigeru

Future wireless communication systems aim at very high data rates. As the medium access control (MAC) protocol plays the central role in determining the overall performance of the wireless system, designing a suitable MAC protocol is critical to fully exploit the benefit of high speed transmission that the physical layer (PHY) offers. In the latest 802.11n standard [2], the problem of long overhead has been addressed adequately but the issue of excessive colliding transmissions, especially in congested situation, remains untouched. The procedure of setting the backoff value is the heart of the 802.11 distributed coordination function (DCF) to avoid collision in which each station makes its own decision on how to avoid collision in the next transmission. However, collision avoidance is a problem that can not be solved by a single station. In this paper, we introduce a new MAC protocol called Intelligent Local Avoided Collision (iLAC) that redefines individual rationality in choosing the backoff counter value to avoid a colliding transmission. The distinguishing feature of iLAC is that it fundamentally changes this decision making process from collision avoidance to collaborative collision prevention. As a result, stations can avoid colliding transmissions with much greater precision. Analytical solution confirms the validity of this proposal and simulation results show that the proposed algorithm outperforms the conventional algorithms by a large margin.

Asymmetric Bidirectional Controlled Quantum Information Transmission via Seven-Particle Entangled State

NASA Astrophysics Data System (ADS)

Sang, Ming-huang; Nie, Li-ping

2017-11-01

We demonstrate that a seven-particle entangled state can be used to realize the deterministic asymmetric bidirectional controlled quantum information transmission by performing only Bell-state measurement and two-particle projective measurement and single-particle measurement. In our protocol, Alice can teleport an arbitrary unknown single-particle state to Bob and at the same time Bob can remotely prepare an arbitrary known two-particle state for Alice via the control of the supervisor Charlie.

Issues in designing transport layer multicast facilities

NASA Technical Reports Server (NTRS)

Dempsey, Bert J.; Weaver, Alfred C.

1990-01-01

Multicasting denotes a facility in a communications system for providing efficient delivery from a message's source to some well-defined set of locations using a single logical address. While modem network hardware supports multidestination delivery, first generation Transport Layer protocols (e.g., the DoD Transmission Control Protocol (TCP) (15) and ISO TP-4 (41)) did not anticipate the changes over the past decade in underlying network hardware, transmission speeds, and communication patterns that have enabled and driven the interest in reliable multicast. Much recent research has focused on integrating the underlying hardware multicast capability with the reliable services of Transport Layer protocols. Here, we explore the communication issues surrounding the design of such a reliable multicast mechanism. Approaches and solutions from the literature are discussed, and four experimental Transport Layer protocols that incorporate reliable multicast are examined.

Self-Learning Power Control in Wireless Sensor Networks.

PubMed

Chincoli, Michele; Liotta, Antonio

2018-01-27

Current trends in interconnecting myriad smart objects to monetize on Internet of Things applications have led to high-density communications in wireless sensor networks. This aggravates the already over-congested unlicensed radio bands, calling for new mechanisms to improve spectrum management and energy efficiency, such as transmission power control. Existing protocols are based on simplistic heuristics that often approach interference problems (i.e., packet loss, delay and energy waste) by increasing power, leading to detrimental results. The scope of this work is to investigate how machine learning may be used to bring wireless nodes to the lowest possible transmission power level and, in turn, to respect the quality requirements of the overall network. Lowering transmission power has benefits in terms of both energy consumption and interference. We propose a protocol of transmission power control through a reinforcement learning process that we have set in a multi-agent system. The agents are independent learners using the same exploration strategy and reward structure, leading to an overall cooperative network. The simulation results show that the system converges to an equilibrium where each node transmits at the minimum power while respecting high packet reception ratio constraints. Consequently, the system benefits from low energy consumption and packet delay.

Self-Learning Power Control in Wireless Sensor Networks

PubMed Central

Liotta, Antonio

2018-01-01

Current trends in interconnecting myriad smart objects to monetize on Internet of Things applications have led to high-density communications in wireless sensor networks. This aggravates the already over-congested unlicensed radio bands, calling for new mechanisms to improve spectrum management and energy efficiency, such as transmission power control. Existing protocols are based on simplistic heuristics that often approach interference problems (i.e., packet loss, delay and energy waste) by increasing power, leading to detrimental results. The scope of this work is to investigate how machine learning may be used to bring wireless nodes to the lowest possible transmission power level and, in turn, to respect the quality requirements of the overall network. Lowering transmission power has benefits in terms of both energy consumption and interference. We propose a protocol of transmission power control through a reinforcement learning process that we have set in a multi-agent system. The agents are independent learners using the same exploration strategy and reward structure, leading to an overall cooperative network. The simulation results show that the system converges to an equilibrium where each node transmits at the minimum power while respecting high packet reception ratio constraints. Consequently, the system benefits from low energy consumption and packet delay. PMID:29382072

Open Source Cybersecurity for the 21st Century

DTIC Science & Technology

2013-03-01

would eventually develop into Transmission Control Protocol/Internet Protocol ( TCP /IP) based on the following ground rules:12  Each distinct...The internet’s design permits any device conforming to modern day protocol standards ( TCP /IP being the most prevalent) to communicate across the... factors , coupled with the internet’s global reach and low cost of entry, are what make securing the cyber domain one of the most complex challenges we

Transport Protocols for Wireless Mesh Networks

NASA Astrophysics Data System (ADS)

Eddie Law, K. L.

Transmission control protocol (TCP) provides reliable connection-oriented services between any two end systems on the Internet. With TCP congestion control algorithm, multiple TCP connections can share network and link resources simultaneously. These TCP congestion control mechanisms have been operating effectively in wired networks. However, performance of TCP connections degrades rapidly in wireless and lossy networks. To sustain the throughput performance of TCP connections in wireless networks, design modifications may be required accordingly in the TCP flow control algorithm, and potentially, in association with other protocols in other layers for proper adaptations. In this chapter, we explain the limitations of the latest TCP congestion control algorithm, and then review some popular designs for TCP connections to operate effectively in wireless mesh network infrastructure.

Internet-Protocol-Based Satellite Bus Architecture Designed

NASA Technical Reports Server (NTRS)

Slywczak, Richard A.

2004-01-01

NASA is designing future complex satellite missions ranging from single satellites and constellations to space networks and sensor webs. These missions require more interoperability, autonomy, and coordination than previous missions; in addition, a desire exists to have scientists retrieve data directly from the satellite rather than a central distribution source. To meet these goals, NASA has been studying the possibility of extending the Transmission Control Protocol/Internet Protocol (TCP/IP) suite for spacebased applications.

Traffic Generator (TrafficGen) Version 1.4.2: Users Guide

DTIC Science & Technology

2016-06-01

events, the user has to enter them manually . We will research and implement a way to better define and organize the multicast addresses so they can be...the network with Transmission Control Protocol and User Datagram Protocol Internet Protocol traffic. Each node generating network traffic in an...TrafficGen Graphical User Interface (GUI) 3 3.1 Anatomy of the User Interface 3 3.2 Scenario Configuration and MGEN Files 4 4. Working with

Advanced information processing system: Authentication protocols for network communication

NASA Technical Reports Server (NTRS)

Harper, Richard E.; Adams, Stuart J.; Babikyan, Carol A.; Butler, Bryan P.; Clark, Anne L.; Lala, Jaynarayan H.

1994-01-01

In safety critical I/O and intercomputer communication networks, reliable message transmission is an important concern. Difficulties of communication and fault identification in networks arise primarily because the sender of a transmission cannot be identified with certainty, an intermediate node can corrupt a message without certainty of detection, and a babbling node cannot be identified and silenced without lengthy diagnosis and reconfiguration . Authentication protocols use digital signature techniques to verify the authenticity of messages with high probability. Such protocols appear to provide an efficient solution to many of these problems. The objective of this program is to develop, demonstrate, and evaluate intercomputer communication architectures which employ authentication. As a context for the evaluation, the authentication protocol-based communication concept was demonstrated under this program by hosting a real-time flight critical guidance, navigation and control algorithm on a distributed, heterogeneous, mixed redundancy system of workstations and embedded fault-tolerant computers.

Intelligent QoS routing algorithm based on improved AODV protocol for Ad Hoc networks

NASA Astrophysics Data System (ADS)

Huibin, Liu; Jun, Zhang

2016-04-01

Mobile Ad Hoc Networks were playing an increasingly important part in disaster reliefs, military battlefields and scientific explorations. However, networks routing difficulties are more and more outstanding due to inherent structures. This paper proposed an improved cuckoo searching-based Ad hoc On-Demand Distance Vector Routing protocol (CSAODV). It elaborately designs the calculation methods of optimal routing algorithm used by protocol and transmission mechanism of communication-package. In calculation of optimal routing algorithm by CS Algorithm, by increasing QoS constraint, the found optimal routing algorithm can conform to the requirements of specified bandwidth and time delay, and a certain balance can be obtained among computation spending, bandwidth and time delay. Take advantage of NS2 simulation software to take performance test on protocol in three circumstances and validate the feasibility and validity of CSAODV protocol. In results, CSAODV routing protocol is more adapt to the change of network topological structure than AODV protocol, which improves package delivery fraction of protocol effectively, reduce the transmission time delay of network, reduce the extra burden to network brought by controlling information, and improve the routing efficiency of network.

Using a CLIPS expert system to automatically manage TCP/IP networks and their components

NASA Technical Reports Server (NTRS)

Faul, Ben M.

1991-01-01

A expert system that can directly manage networks components on a Transmission Control Protocol/Internet Protocol (TCP/IP) network is described. Previous expert systems for managing networks have focused on managing network faults after they occur. However, this proactive expert system can monitor and control network components in near real time. The ability to directly manage network elements from the C Language Integrated Production System (CLIPS) is accomplished by the integration of the Simple Network Management Protocol (SNMP) and a Abstract Syntax Notation (ASN) parser into the CLIPS artificial intelligence language.

OSI and TCP/IP

NASA Technical Reports Server (NTRS)

Randolph, Lynwood P.

1994-01-01

The Open Systems Interconnection Transmission Control Protocol/Internet Protocol (OSI TCP/IP) and the Government Open Systems Interconnection Profile (GOSIP) are compared and described in terms of Federal internetworking. The organization and functions of the Federal Internetworking Requirements Panel (FIRP) are discussed and the panel's conclusions and recommendations with respect to the standards and implementation of the National Information Infrastructure (NII) are presented.

TCP Performance Enhancement Over Iridium

NASA Technical Reports Server (NTRS)

Torgerson, Leigh; Hutcherson, Joseph; McKelvey, James

2007-01-01

In support of iNET maturation, NASA-JPL has collaborated with NASA-Dryden to develop, test and demonstrate an over-the-horizon vehicle-to-ground networking capability, using Iridium as the vehicle-to-ground communications link for relaying critical vehicle telemetry. To ensure reliability concerns are met, the Space Communications Protocol Standards (SCPS) transport protocol was investigated for its performance characteristics in this environment. In particular, the SCPS-TP software performance was compared to that of the standard Transmission Control Protocol (TCP) over the Internet Protocol (IP). This paper will report on the results of this work.

A Java Applet for Illustrating Internet Error Control

ERIC Educational Resources Information Center

Holliday, Mark A.

2004-01-01

This paper discusses the author's experiences developing a Java applet that illustrates how error control is implemented in the Transmission Control Protocol (TCP). One section discusses the concepts which the TCP error control Java applet is intended to convey, while the nature of the Java applet is covered in another section. The author…

A new, ultra-low latency data transmission protocol for Earthquake Early Warning Systems

NASA Astrophysics Data System (ADS)

Hill, P.; Hicks, S. P.; McGowan, M.

2016-12-01

One measure used to assess the performance of Earthquake Early Warning Systems (EEWS) is the delay time between earthquake origin and issued alert. EEWS latency is dependent on a number of sources (e.g. P-wave propagation, digitisation, transmission, receiver processing, triggering, event declaration). Many regional seismic networks use the SEEDlink protocol; however, packet size is fixed to 512-byte miniSEED records, resulting in transmission latencies of >0.5 s. Data packetisation is seen as one of the main sources of delays in EEWS (Brown et al., 2011). Optimising data-logger and telemetry configurations is a cost-effective strategy to improve EEWS alert times (Behr et al., 2015). Digitisers with smaller, selectable packets can result in faster alerts (Sokos et al., 2016). We propose a new seismic protocol for regional seismic networks benefiting low-latency applications such as EEWS. The protocol, based on Güralp's existing GDI-link format is an efficient and flexible method to exchange data between seismic stations and data centers for a range of network configurations. The main principle is to stream data sample-by-sample instead of fixed-length packets to minimise transmission latency. Self-adaptive packetisation with compression maximises available telemetry bandwidth. Highly flexible metadata fields within GDI-link are compatible with existing miniSEED definitions. Data is sent as integers or floats, supporting a wide range of data formats, including discrete parameters such as Pd & τC for on-site earthquake early warning. Other advantages include: streaming station state-of-health information, instrument control, support of backfilling and fail-over strategies during telemetry outages. Based on tests carried out on the Güralp Minimus data-logger, we show our new protocol can reduce transmission latency to as low as 1 ms. The low-latency protocol is currently being implemented with common processing packages. The results of these tests will help to highlight latency levels that can be achieved with next-generation EEWS.

A reliable transmission protocol for ZigBee-based wireless patient monitoring.

PubMed

Chen, Shyr-Kuen; Kao, Tsair; Chan, Chia-Tai; Huang, Chih-Ning; Chiang, Chih-Yen; Lai, Chin-Yu; Tung, Tse-Hua; Wang, Pi-Chung

2012-01-01

Patient monitoring systems are gaining their importance as the fast-growing global elderly population increases demands for caretaking. These systems use wireless technologies to transmit vital signs for medical evaluation. In a multihop ZigBee network, the existing systems usually use broadcast or multicast schemes to increase the reliability of signals transmission; however, both the schemes lead to significantly higher network traffic and end-to-end transmission delay. In this paper, we present a reliable transmission protocol based on anycast routing for wireless patient monitoring. Our scheme automatically selects the closest data receiver in an anycast group as a destination to reduce the transmission latency as well as the control overhead. The new protocol also shortens the latency of path recovery by initiating route recovery from the intermediate routers of the original path. On the basis of a reliable transmission scheme, we implement a ZigBee device for fall monitoring, which integrates fall detection, indoor positioning, and ECG monitoring. When the triaxial accelerometer of the device detects a fall, the current position of the patient is transmitted to an emergency center through a ZigBee network. In order to clarify the situation of the fallen patient, 4-s ECG signals are also transmitted. Our transmission scheme ensures the successful transmission of these critical messages. The experimental results show that our scheme is fast and reliable. We also demonstrate that our devices can seamlessly integrate with the next generation technology of wireless wide area network, worldwide interoperability for microwave access, to achieve real-time patient monitoring.

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...

Photonic-based liquid level transmitter using Mach-Zehnder interferometer for industrial application

NASA Astrophysics Data System (ADS)

Singh, Yadvendra; Raghuwanshi, Sanjeev K.; Kumar, Manish

2018-02-01

In the present scenario the process control industries mainly uses 1-5 Volt or 4-20 mA protocol for transmitting the measured signal to remote location operators. These types of protocol prone to interference and limited data transfer rate. To overcome these types of limitation we proposed photonic based transmitter for liquid level measurement which will enhance data transfer rate and interference reduction to eliminate noise signal in the channel during transmission to make transmission more reliable, accurate and consistent in performance. The required mathematical derivation and the principle of operation of the transmitter are shown in the paper.

Point-to-Point Multicast Communications Protocol

NASA Technical Reports Server (NTRS)

Byrd, Gregory T.; Nakano, Russell; Delagi, Bruce A.

1987-01-01

This paper describes a protocol to support point-to-point interprocessor communications with multicast. Dynamic, cut-through routing with local flow control is used to provide a high-throughput, low-latency communications path between processors. In addition multicast transmissions are available, in which copies of a packet are sent to multiple destinations using common resources as much as possible. Special packet terminators and selective buffering are introduced to avoid a deadlock during multicasts. A simulated implementation of the protocol is also described.

A History of the Improvement of Internet Protocols Over Satellites Using ACTS

NASA Technical Reports Server (NTRS)

Allman, Mark; Kruse, Hans; Ostermann, Shawn

2000-01-01

This paper outlines the main results of a number of ACTS experiments on the efficacy of using standard Internet protocols over long-delay satellite channels. These experiments have been jointly conducted by NASAs Glenn Research Center and Ohio University over the last six years. The focus of our investigations has been the impact of long-delay networks with non-zero bit-error rates on the performance of the suite of Internet protocols. In particular, we have focused on the most widely used transport protocol, the Transmission Control Protocol (TCP), as well as several application layer protocols. This paper presents our main results, as well as references to more verbose discussions of our experiments.

Distance bounded energy detecting ultra-wideband impulse radio secure protocol.

PubMed

Hedin, Daniel S; Kollmann, Daniel T; Gibson, Paul L; Riehle, Timothy H; Seifert, Gregory J

2014-01-01

We present a demonstration of a novel protocol for secure transmissions on a Ultra-wideband impulse radio that includes distance bounding. Distance bounding requires radios to be within a certain radius to communicate. This new protocol can be used in body area networks for medical devices where security is imperative. Many current wireless medical devices were not designed with security as a priority including devices that can be life threatening if controlled by a hacker. This protocol provides multiple levels of security including encryption and a distance bounding test to prevent long distance attacks.

An Efficient and QoS Supported Multichannel MAC Protocol for Vehicular Ad Hoc Networks

PubMed Central

Tan, Guozhen; Yu, Chao

2017-01-01

Vehicular Ad Hoc Networks (VANETs) employ multichannel to provide a variety of safety and non-safety (transport efficiency and infotainment) applications, based on the IEEE 802.11p and IEEE 1609.4 protocols. Different types of applications require different levels Quality-of-Service (QoS) support. Recently, transport efficiency and infotainment applications (e.g., electronic map download and Internet access) have received more and more attention, and this kind of applications is expected to become a big market driver in a near future. In this paper, we propose an Efficient and QoS supported Multichannel Medium Access Control (EQM-MAC) protocol for VANETs in a highway environment. The EQM-MAC protocol utilizes the service channel resources for non-safety message transmissions during the whole synchronization interval, and it dynamically adjusts minimum contention window size for different non-safety services according to the traffic conditions. Theoretical model analysis and extensive simulation results show that the EQM-MAC protocol can support QoS services, while ensuring the high saturation throughput and low transmission delay for non-safety applications. PMID:28991217

Transitioning the Tactical Marine Corps to IPv6

DTIC Science & Technology

2011-09-01

SUT System Under Test SYSCOM Systems Command (synonymous with MCSC) TCP Transmission Control Protocol TDS Tactical Data Systems TDN...capability to provide services to the Marine Corps Tactical Data Systems ( TDS ) and other DDS-M systems. The 2 DDS-M can function as the file server...Intelligence ( ATI ) program provides comprehensive application protocols and attacks, as well as feature updates and responsive service and support with

Active Computer Network Defense: An Assessment

DTIC Science & Technology

2001-04-01

sufficient base of knowledge in information technology can be assumed to be working on some form of computer network warfare, even if only defensive in...the Defense Information Infrastructure (DII) to attack. Transmission Control Protocol/ Internet Protocol (TCP/IP) networks are inherently resistant to...aims to create this part of information superiority, and computer network defense is one of its fundamental components. Most of these efforts center

Development of a Protocol for Automated Glucose Measurement Transmission Used in Clinical Decision Support Systems Based on the Continua Design Guidelines.

PubMed

Meyer, Markus; Donsa, Klaus; Truskaller, Thomas; Frohner, Matthias; Pohn, Birgit; Felfernig, Alexander; Sinner, Frank; Pieber, Thomas

2018-01-01

A fast and accurate data transmission from glucose meter to clinical decision support systems (CDSSs) is crucial for the management of type 2 diabetes mellitus since almost all therapeutic interventions are derived from glucose measurements. Aim was to develop a prototype of an automated glucose measurement transmission protocol based on the Continua Design Guidelines and to embed the protocol into a CDSS used by healthcare professionals. A literature and market research was performed to analyze the state-of-the-art and thereupon develop, integrate and validate an automated glucose measurement transmission protocol in an iterative process. Findings from literature and market research guided towards the development of a standardized glucose measurement transmission protocol using a middleware. The interface description to communicate with the glucose meter was illustrated and embedded into a CDSS. A prototype of an interoperable transmission of glucose measurements was developed and implemented in a CDSS presenting a promising way to reduce medication errors and improve user satisfaction.

Medium Access Control for Opportunistic Concurrent Transmissions under Shadowing Channels

PubMed Central

Son, In Keun; Mao, Shiwen; Hur, Seung Min

2009-01-01

We study the problem of how to alleviate the exposed terminal effect in multi-hop wireless networks in the presence of log-normal shadowing channels. Assuming node location information, we propose an extension of the IEEE 802.11 MAC protocol that sched-ules concurrent transmissions in the presence of log-normal shadowing, thus mitigating the exposed terminal problem and improving network throughput and delay performance. We observe considerable improvements in throughput and delay achieved over the IEEE 802.11 MAC under various network topologies and channel conditions in ns-2 simulations, which justify the importance of considering channel randomness in MAC protocol design for multi-hop wireless networks. PMID:22408556

A data transmission method for particle physics experiments based on Ethernet physical layer

NASA Astrophysics Data System (ADS)

Huang, Xi-Ru; Cao, Ping; Zheng, Jia-Jun

2015-11-01

Due to its advantages of universality, flexibility and high performance, fast Ethernet is widely used in readout system design for modern particle physics experiments. However, Ethernet is usually used together with the TCP/IP protocol stack, which makes it difficult to implement readout systems because designers have to use the operating system to process this protocol. Furthermore, TCP/IP degrades the transmission efficiency and real-time performance. To maximize the performance of Ethernet in physics experiment applications, a data readout method based on the physical layer (PHY) is proposed. In this method, TCP/IP is replaced with a customized and simple protocol, which makes it easier to implement. On each readout module, data from the front-end electronics is first fed into an FPGA for protocol processing and then sent out to a PHY chip controlled by this FPGA for transmission. This kind of data path is fully implemented by hardware. From the side of the data acquisition system (DAQ), however, the absence of a standard protocol causes problems for the network related applications. To solve this problem, in the operating system kernel space, data received by the network interface card is redirected from the traditional flow to a specified memory space by a customized program. This memory space can easily be accessed by applications in user space. For the purpose of verification, a prototype system has been designed and implemented. Preliminary test results show that this method can meet the requirements of data transmission from the readout module to the DAQ with an efficient and simple manner. Supported by National Natural Science Foundation of China (11005107) and Independent Projects of State Key Laboratory of Particle Detection and Electronics (201301)

Lightweight SIP/SDP compression scheme (LSSCS)

NASA Astrophysics Data System (ADS)

Wu, Jian J.; Demetrescu, Cristian

2001-10-01

In UMTS new IP based services with tight delay constraints will be deployed over the W-CDMA air interface such as IP multimedia and interactive services. To integrate the wireline and wireless IP services, 3GPP standard forum adopted the Session Initiation Protocol (SIP) as the call control protocol for the UMTS Release 5, which will implement next generation, all IP networks for real-time QoS services. In the current form the SIP protocol is not suitable for wireless transmission due to its large message size which will need either a big radio pipe for transmission or it will take far much longer to transmit than the current GSM Call Control (CC) message sequence. In this paper we present a novel compression algorithm called Lightweight SIP/SDP Compression Scheme (LSSCS), which acts at the SIP application layer and therefore removes the information redundancy before it is sent to the network and transport layer. A binary octet-aligned header is added to the compressed SIP/SDP message before sending it to the network layer. The receiver uses this binary header as well as the pre-cached information to regenerate the original SIP/SDP message. The key features of the LSSCS compression scheme are presented in this paper along with implementation examples. It is shown that this compression algorithm makes SIP transmission efficient over the radio interface without losing the SIP generality and flexibility.

Robot formation control in stealth mode with scalable team size

NASA Astrophysics Data System (ADS)

Yu, Hongjun; Shi, Peng; Lim, Cheng-Chew

2016-11-01

In situations where robots need to keep electromagnetic silent in a formation, communication channels become unavailable. Moreover, as passive displacement sensors are used, limited sensing ranges are inevitable due to power insufficiency and limited noise reduction. To address the formation control problem for a scalable team of robots subject to the above restrictions, a flexible strategy is necessary. In this paper, under the assumption that the data transmission among the robots is not available, a novel controller and a protocol are designed that do not rely on communication. As the controller only drives the robots to a partially desired formation, a distributed coordination protocol is proposed to resolve the imperfections. It is shown that the effectiveness of the controller and the protocol rely on the formation connectivity, and a condition is given on the sensing range. Simulations are conducted to illustrate the feasibility and advantages of the new design scheme developed.

Deployment of 802.15.4 Sensor Networks for C4ISR Operations

DTIC Science & Technology

2006-06-01

43 Figure 20.MSP410CA Dense Grid Monitoring (Crossbow User’s Manual, 2005). ....................................44 Figure 21.(a)MICA2 without...Deployment of Sensor Grid (COASTS OPORD, 2006). ...56 Figure 27.Topology View of Two Nodes and Base Station .......57 Figure 28.Nodes Employing Multi...Random Access Memory TCP/IP Transmission Control Protocol/Internet Protocol TinyOS Tiny Micro Threading Operating System UARTs Universal

An Energy Efficient Power Control Protocol for Ad Hoc Networks Using Directional Antennas

NASA Astrophysics Data System (ADS)

Quiroz-Perez, Carlos; Gulliver, T. Aaron

A wireless ad hoc network is a collection of mobile nodes that can communicate with each other. Typically, nodes employ omnidirectional antennas. The use of directional antennas can increase spatial reuse, reduce the number of hops to a destination, reduce interference, and increase the transmission range in a specific direction. This is because omnidirectional antennas radiate equally in all directions, limiting the transmission range.

A Routing Protocol for Multisink Wireless Sensor Networks in Underground Coalmine Tunnels

PubMed Central

Xia, Xu; Chen, Zhigang; Liu, Hui; Wang, Huihui; Zeng, Feng

2016-01-01

Traditional underground coalmine monitoring systems are mainly based on the use of wired transmission. However, when cables are damaged during an accident, it is difficult to obtain relevant data on environmental parameters and the emergency situation underground. To address this problem, the use of wireless sensor networks (WSNs) has been proposed. However, the shape of coalmine tunnels is not conducive to the deployment of WSNs as they are long and narrow. Therefore, issues with the network arise, such as extremely large energy consumption, very weak connectivity, long time delays, and a short lifetime. To solve these problems, in this study, a new routing protocol algorithm for multisink WSNs based on transmission power control is proposed. First, a transmission power control algorithm is used to negotiate the optimal communication radius and transmission power of each sink. Second, the non-uniform clustering idea is adopted to optimize the cluster head selection. Simulation results are subsequently compared to the Centroid of the Nodes in a Partition (CNP) strategy and show that the new algorithm delivers a good performance: power efficiency is increased by approximately 70%, connectivity is increased by approximately 15%, the cluster interference is diminished by approximately 50%, the network lifetime is increased by approximately 6%, and the delay is reduced with an increase in the number of sinks. PMID:27916917

A Routing Protocol for Multisink Wireless Sensor Networks in Underground Coalmine Tunnels.

PubMed

Xia, Xu; Chen, Zhigang; Liu, Hui; Wang, Huihui; Zeng, Feng

2016-11-30

Traditional underground coalmine monitoring systems are mainly based on the use of wired transmission. However, when cables are damaged during an accident, it is difficult to obtain relevant data on environmental parameters and the emergency situation underground. To address this problem, the use of wireless sensor networks (WSNs) has been proposed. However, the shape of coalmine tunnels is not conducive to the deployment of WSNs as they are long and narrow. Therefore, issues with the network arise, such as extremely large energy consumption, very weak connectivity, long time delays, and a short lifetime. To solve these problems, in this study, a new routing protocol algorithm for multisink WSNs based on transmission power control is proposed. First, a transmission power control algorithm is used to negotiate the optimal communication radius and transmission power of each sink. Second, the non-uniform clustering idea is adopted to optimize the cluster head selection. Simulation results are subsequently compared to the Centroid of the Nodes in a Partition (CNP) strategy and show that the new algorithm delivers a good performance: power efficiency is increased by approximately 70%, connectivity is increased by approximately 15%, the cluster interference is diminished by approximately 50%, the network lifetime is increased by approximately 6%, and the delay is reduced with an increase in the number of sinks.

L2-LBMT: A Layered Load Balance Routing Protocol for underwater multimedia data transmission

NASA Astrophysics Data System (ADS)

Lv, Ze; Tang, Ruichun; Tao, Ye; Sun, Xin; Xu, Xiaowei

2017-12-01

Providing highly efficient underwater transmission of mass multimedia data is challenging due to the particularities of the underwater environment. Although there are many schemes proposed to optimize the underwater acoustic network communication protocols, from physical layer, data link layer, network layer to transport layer, the existing routing protocols for underwater wireless sensor network (UWSN) still cannot well deal with the problems in transmitting multimedia data because of the difficulties involved in high energy consumption, low transmission reliability or high transmission delay. It prevents us from applying underwater multimedia data to real-time monitoring of marine environment in practical application, especially in emergency search, rescue operation and military field. Therefore, the inefficient transmission of marine multimedia data has become a serious problem that needs to be solved urgently. In this paper, A Layered Load Balance Routing Protocol (L2-LBMT) is proposed for underwater multimedia data transmission. In L2-LBMT, we use layered and load-balance Ad Hoc Network to transmit data, and adopt segmented data reliable transfer (SDRT) protocol to improve the data transport reliability. And a 3-node variant of tornado (3-VT) code is also combined with the Ad Hoc Network to transmit little emergency data more quickly. The simulation results show that the proposed protocol can balance energy consumption of each node, effectively prolong the network lifetime and reduce transmission delay of marine multimedia data.

Protocol independent transmission method in software defined optical network

NASA Astrophysics Data System (ADS)

Liu, Yuze; Li, Hui; Hou, Yanfang; Qiu, Yajun; Ji, Yuefeng

2016-10-01

With the development of big data and cloud computing technology, the traditional software-defined network is facing new challenges (e.i., ubiquitous accessibility, higher bandwidth, more flexible management and greater security). Using a proprietary protocol or encoding format is a way to improve information security. However, the flow, which carried by proprietary protocol or code, cannot go through the traditional IP network. In addition, ultra- high-definition video transmission service once again become a hot spot. Traditionally, in the IP network, the Serial Digital Interface (SDI) signal must be compressed. This approach offers additional advantages but also bring some disadvantages such as signal degradation and high latency. To some extent, HD-SDI can also be regard as a proprietary protocol, which need transparent transmission such as optical channel. However, traditional optical networks cannot support flexible traffics . In response to aforementioned challenges for future network, one immediate solution would be to use NFV technology to abstract the network infrastructure and provide an all-optical switching topology graph for the SDN control plane. This paper proposes a new service-based software defined optical network architecture, including an infrastructure layer, a virtualization layer, a service abstract layer and an application layer. We then dwell on the corresponding service providing method in order to implement the protocol-independent transport. Finally, we experimentally evaluate that proposed service providing method can be applied to transmit the HD-SDI signal in the software-defined optical network.

Advanced communications technology satellite high burst rate link evaluation terminal communication protocol software user's guide, version 1.0

NASA Technical Reports Server (NTRS)

Reinhart, Richard C.

1993-01-01

The Communication Protocol Software was developed at the NASA Lewis Research Center to support the Advanced Communications Technology Satellite High Burst Rate Link Evaluation Terminal (ACTS HBR-LET). The HBR-LET is an experimenters terminal to communicate with the ACTS for various experiments by government, university, and industry agencies. The Communication Protocol Software is one segment of the Control and Performance Monitor (C&PM) Software system of the HBR-LET. The Communication Protocol Software allows users to control and configure the Intermediate Frequency Switch Matrix (IFSM) on board the ACTS to yield a desired path through the spacecraft payload. Besides IFSM control, the C&PM Software System is also responsible for instrument control during HBR-LET experiments, uplink power control of the HBR-LET to demonstrate power augmentation during signal fade events, and data display. The Communication Protocol Software User's Guide, Version 1.0 (NASA CR-189162) outlines the commands and procedures to install and operate the Communication Protocol Software. Configuration files used to control the IFSM, operator commands, and error recovery procedures are discussed. The Communication Protocol Software Maintenance Manual, Version 1.0 (NASA CR-189163, to be published) is a programmer's guide to the Communication Protocol Software. This manual details the current implementation of the software from a technical perspective. Included is an overview of the Communication Protocol Software, computer algorithms, format representations, and computer hardware configuration. The Communication Protocol Software Test Plan (NASA CR-189164, to be published) provides a step-by-step procedure to verify the operation of the software. Included in the Test Plan is command transmission, telemetry reception, error detection, and error recovery procedures.

Secure and Robust Transmission and Verification of Unknown Quantum States in Minkowski Space

PubMed Central

Kent, Adrian; Massar, Serge; Silman, Jonathan

2014-01-01

An important class of cryptographic applications of relativistic quantum information work as follows. B generates a random qudit and supplies it to A at point P. A is supposed to transmit it at near light speed c to to one of a number of possible pairwise spacelike separated points Q1, …, Qn. A's transmission is supposed to be secure, in the sense that B cannot tell in advance which Qj will be chosen. This poses significant practical challenges, since secure reliable long-range transmission of quantum data at speeds near to c is presently not easy. Here we propose different techniques to overcome these diffculties. We introduce protocols that allow secure long-range implementations even when both parties control only widely separated laboratories of small size. In particular we introduce a protocol in which A needs send the qudit only over a short distance, and securely transmits classical information (for instance using a one time pad) over the remaining distance. We further show that by using parallel implementations of the protocols security can be maintained in the presence of moderate amounts of losses and errors. PMID:24469425

Controlled Bidirectional Quantum Secure Direct Communication

PubMed Central

Chou, Yao-Hsin; Lin, Yu-Ting; Zeng, Guo-Jyun; Lin, Fang-Jhu; Chen, Chi-Yuan

2014-01-01

We propose a novel protocol for controlled bidirectional quantum secure communication based on a nonlocal swap gate scheme. Our proposed protocol would be applied to a system in which a controller (supervisor/Charlie) controls the bidirectional communication with quantum information or secret messages between legitimate users (Alice and Bob). In this system, the legitimate users must obtain permission from the controller in order to exchange their respective quantum information or secret messages simultaneously; the controller is unable to obtain any quantum information or secret messages from the decoding process. Moreover, the presence of the controller also avoids the problem of one legitimate user receiving the quantum information or secret message before the other, and then refusing to help the other user decode the quantum information or secret message. Our proposed protocol is aimed at protecting against external and participant attacks on such a system, and the cost of transmitting quantum bits using our protocol is less than that achieved in other studies. Based on the nonlocal swap gate scheme, the legitimate users exchange their quantum information or secret messages without transmission in a public channel, thus protecting against eavesdroppers stealing the secret messages. PMID:25006596

ECS: efficient communication scheduling for underwater sensor networks.

PubMed

Hong, Lu; Hong, Feng; Guo, Zhongwen; Li, Zhengbao

2011-01-01

TDMA protocols have attracted a lot of attention for underwater acoustic sensor networks (UWSNs), because of the unique characteristics of acoustic signal propagation such as great energy consumption in transmission, long propagation delay and long communication range. Previous TDMA protocols all allocated transmission time to nodes based on discrete time slots. This paper proposes an efficient continuous time scheduling TDMA protocol (ECS) for UWSNs, including the continuous time based and sender oriented conflict analysis model, the transmission moment allocation algorithm and the distributed topology maintenance algorithm. Simulation results confirm that ECS improves network throughput by 20% on average, compared to existing MAC protocols.

Research into alternative network approaches for space operations

NASA Technical Reports Server (NTRS)

Kusmanoff, Antone L.; Barton, Timothy J.

1990-01-01

The main goal is to resolve the interoperability problem of applications employing DOD TCP/IP (Department of Defence Transmission Control Protocol/Internet Protocol) family of protocols on a CCITT/ISO based network. The objective is to allow them to communicate over the CCITT/ISO protocol GPLAN (General Purpose Local Area Network) network without modification to the user's application programs. There were two primary assumptions associated with the solution that was actually realized. The first is that the solution had to allow for future movement to the exclusive use of the CCITT/ISO standards. The second is that the solution had to be software transparent to the currently installed TCP/IP and CCITT/ISO user application programs.

Energy consumption and control response evaluations of AODV routing in WSANs for building-temperature control.

PubMed

Booranawong, Apidet; Teerapabkajorndet, Wiklom; Limsakul, Chusak

2013-06-27

The main objective of this paper is to investigate the effects of routing protocols on wireless sensor and actuator networks (WSANs), focusing on the control system response and the energy consumption of nodes in a network. We demonstrate that routing algorithms designed without considering the relationship between communication and control cannot be appropriately used in wireless networked control applications. For this purpose, an ad-hoc on-demand distance vector (AODV) routing, an IEEE 802.15.4, and a building-temperature control system are employed for this exploration. The findings from our scenarios show that the AODV routing can select a path with a high traffic load for data transmission. It takes a long time before deciding to change a new route although it experiences the unsuccessful transmission of packets. As a result, the desirable control target cannot be achieved in time, and nodes consume more energy due to frequent packet collisions and retransmissions. Consequently, we propose a simple routing solution to alleviate these research problems by modifying the original AODV routing protocol. The delay-threshold is considered to avoid any congested connection during routing procedures. The simulation results demonstrate that our solution can be appropriately applied in WSANs. Both the energy consumption and the control system response are improved.

Decreased muscle endurance associated with diabetic neuropathy may be attributed partially to neuromuscular transmission failure

PubMed Central

Kimpinski, Kurt; Doherty, Timothy J.; Rice, Charles L.

2015-01-01

Diabetic polyneuropathy (DPN) can cause muscle atrophy, weakness, contractile slowing, and neuromuscular transmission instability. Our objective was to assess the response of the impaired neuromuscular system of DPN in humans when stressed with a sustained maximal voluntary contraction (MVC). Baseline MVC and evoked dorsiflexor contractile properties were assessed in DPN patients (n = 10) and controls (n = 10). Surface electromyography was used to record tibialis anterior evoked maximal compound muscle action potentials (CMAPs) and neuromuscular activity during MVCs. Participants performed a sustained isometric dorsiflexion MVC for which task termination was determined by the inability to sustain ≥60% MVC torque. The fatigue protocol was immediately followed by a maximal twitch, with additional maximal twitches and MVCs assessed at 30 s and 2 min postfatigue. DPN patients fatigued ∼21% more quickly than controls (P < 0.05) and featured less relative electromyographic activity during the first one-third of the fatigue protocol compared with controls (P < 0.05). Immediately following fatigue, maximal twitch torque was reduced similarly (∼20%) in both groups, and concurrently CMAPs were reduced (∼12%) in DPN patients, whereas they were unaffected in controls (P > 0.05). Twitch torque and CMAP amplitude recovered to baseline 30 s postfatigue. Additionally, at 30 s postfatigue, both groups had similar (∼10%) reductions in MVC torque relative to baseline, and MVC strength recovered by 2 min postfatigue. We conclude DPN patients possess less endurance than controls, and neuromuscular transmission failure may contribute to this greater fatigability. PMID:25663671

Spacelab system analysis: The modified free access protocol: An access protocol for communication systems with periodic and Poisson traffic

NASA Technical Reports Server (NTRS)

Ingels, Frank; Owens, John; Daniel, Steven

1989-01-01

The protocol definition and terminal hardware for the modified free access protocol, a communications protocol similar to Ethernet, are developed. A MFA protocol simulator and a CSMA/CD math model are also developed. The protocol is tailored to communication systems where the total traffic may be divided into scheduled traffic and Poisson traffic. The scheduled traffic should occur on a periodic basis but may occur after a given event such as a request for data from a large number of stations. The Poisson traffic will include alarms and other random traffic. The purpose of the protocol is to guarantee that scheduled packets will be delivered without collision. This is required in many control and data collection systems. The protocol uses standard Ethernet hardware and software requiring minimum modifications to an existing system. The modification to the protocol only affects the Ethernet transmission privileges and does not effect the Ethernet receiver.

Protocol for a Delay-Tolerant Data-Communication Network

NASA Technical Reports Server (NTRS)

Torgerson, Jordan; Hooke, Adrian; Burleigh, Scott; Fall, Kevin

2004-01-01

As its name partly indicates, the Delay-Tolerant Networking (DTN) Bundle Protocol is a protocol for delay-tolerant transmission of data via communication networks. This protocol was conceived as a result of studies of how to adapt Internet protocols so that Internet-like services could be provided across interplanetary distances in support of deep-space exploration. The protocol, and software to implement the protocol, is being developed in collaboration among experts at NASA's Jet Propulsion Laboratory and other institutions. No current Internet protocols can accommodate long transmission delay times or intermittent link connectivity. The DTN Bundle Protocol represents a departure from the standard Internet assumption that a continuous path is available from a host computer to a client computer: It provides for routing of data through networks that may be disjointed and may be characterized by long transmission delays. In addition to networks that include deepspace communication links, examples of such networks include terrestrial ones within which branches are temporarily disconnected. The protocol is based partly on the definition of a message-based overlay above the transport layers of the networks on which it is hosted.

Intelligent Cooperative MAC Protocol for Balancing Energy Consumption

NASA Astrophysics Data System (ADS)

Wu, S.; Liu, K.; Huang, B.; Liu, F.

To extend the lifetime of wireless sensor networks, we proposed an intelligent balanced energy consumption cooperative MAC protocol (IBEC-CMAC) based on the multi-node cooperative transmission model. The protocol has priority to access high-quality channels for reducing energy consumption of each transmission. It can also balance the energy consumption among cooperative nodes by using high residual energy nodes instead of excessively consuming some node's energy. Simulation results show that IBEC-CMAC can obtain longer network lifetime and higher energy utilization than direct transmission.

Vehicle Density Based Forwarding Protocol for Safety Message Broadcast in VANET

PubMed Central

Huang, Jiawei; Wang, Jianxin

2014-01-01

In vehicular ad hoc networks (VANETs), the medium access control (MAC) protocol is of great importance to provide time-critical safety applications. Contemporary multihop broadcast protocols in VANETs usually choose the farthest node in broadcast range as the forwarder to reduce the number of forwarding hops. However, in this paper, we demonstrate that the farthest forwarder may experience large contention delay in case of high vehicle density. We propose an IEEE 802.11-based multihop broadcast protocol VDF to address the issue of emergency message dissemination. To achieve the tradeoff between contention delay and forwarding hops, VDF adaptably chooses the forwarder according to the vehicle density. Simulation results show that, due to its ability to decrease the transmission collisions, the proposed protocol can provide significantly lower broadcast delay. PMID:25121125

ECS: Efficient Communication Scheduling for Underwater Sensor Networks

PubMed Central

Hong, Lu; Hong, Feng; Guo, Zhongwen; Li, Zhengbao

2011-01-01

TDMA protocols have attracted a lot of attention for underwater acoustic sensor networks (UWSNs), because of the unique characteristics of acoustic signal propagation such as great energy consumption in transmission, long propagation delay and long communication range. Previous TDMA protocols all allocated transmission time to nodes based on discrete time slots. This paper proposes an efficient continuous time scheduling TDMA protocol (ECS) for UWSNs, including the continuous time based and sender oriented conflict analysis model, the transmission moment allocation algorithm and the distributed topology maintenance algorithm. Simulation results confirm that ECS improves network throughput by 20% on average, compared to existing MAC protocols. PMID:22163775

Quantum cryptography as a retrodiction problem.

PubMed

Werner, A H; Franz, T; Werner, R F

2009-11-27

We propose a quantum key distribution protocol based on a quantum retrodiction protocol, known as the Mean King problem. The protocol uses a two way quantum channel. We show security against coherent attacks in a transmission-error free scenario, even if Eve is allowed to attack both transmissions. This establishes a connection between retrodiction and key distribution.

Remote control of the industry processes. POWERLINK protocol application

NASA Astrophysics Data System (ADS)

Wóbel, A.; Paruzel, D.; Paszkiewicz, B.

2017-08-01

The present technological development enables the use of solutions characterized by a lower failure rate, and work with greater precision. This allows you to obtain the most efficient production, high speed production and reliability of individual components. The main scope of this article was POWERLINK protocol application for communication with the controller B & R through communication Ethernet for recording process parameters. This enables control of run production cycle using an internal network connected to the PC industry. Knowledge of the most important parameters of the production in real time allows detecting of a failure immediately after occurrence. For this purpose, the position of diagnostic use driver X20CP1301 B&R to record measurement data such as pressure, temperature valve between the parties and the torque required to change the valve setting was made. The use of POWERLINK protocol allows for the transmission of information on the status of every 200 μs.

A Smart Collaborative Routing Protocol for Reliable Data Diffusion in IoT Scenarios.

PubMed

Ai, Zheng-Yang; Zhou, Yu-Tong; Song, Fei

2018-06-13

It is knotty for current routing protocols to meet the needs of reliable data diffusion during the Internet of Things (IoT) deployments. Due to the random placement, limited resources and unattended features of existing sensor nodes, the wireless transmissions are easily exposed to unauthorized users, which becomes a vulnerable area for various malicious attacks, such as wormhole and Sybil attacks. However, the scheme based on geographic location is a suitable candidate to defend against them. This paper is inspired to propose a smart collaborative routing protocol, Geographic energy aware routing and Inspecting Node (GIN), for guaranteeing the reliability of data exchanging. The proposed protocol integrates the directed diffusion routing, Greedy Perimeter Stateless Routing (GPSR), and the inspecting node mechanism. We first discuss current wireless routing protocols from three diverse perspectives (improving transmission rate, shortening transmission range and reducing transmission consumption). Then, the details of GIN, including the model establishment and implementation processes, are presented by means of the theoretical analysis. Through leveraging the game theory, the inspecting node is elected to monitor the network behaviors. Thirdly, we evaluate the network performances, in terms of transmission delay, packet loss ratio, and throughput, between GIN and three traditional schemes (i.e., Flooding, GPSR, and GEAR). The simulation results illustrate that the proposed protocol is able to outperform the others.

Recommended Methodology for Inter-Service/Agency Automated Message Processing Exchange (I-S/A AMPE). Cost and Schedule Analysis of Security Alternatives.

DTIC Science & Technology

1982-02-23

segregate the computer and storage from the outside world 2. Administrative security to control access to secure computer facilities 3. Network security to...Classification Alternative A- 8 NETWORK KG GENSER DSSCS AMPE TERMINALS TP No. 022-4668-A Figure A-2. Dedicated Switching Architecture Alternative A- 9...communications protocol with the network and GENSER message transmission to the - I-S/A AMPE processor. 7. DSSCS TPU - Handles communications protocol with

A Robust and Energy-Efficient Transport Protocol for Cognitive Radio Sensor Networks

PubMed Central

Salim, Shelly; Moh, Sangman

2014-01-01

A cognitive radio sensor network (CRSN) is a wireless sensor network in which sensor nodes are equipped with cognitive radio. CRSNs benefit from cognitive radio capabilities such as dynamic spectrum access and transmission parameters reconfigurability; but cognitive radio also brings additional challenges and leads to higher energy consumption. Motivated to improve the energy efficiency in CRSNs, we propose a robust and energy-efficient transport protocol (RETP). The novelties of RETP are two-fold: (I) it combines distributed channel sensing and channel decision with centralized schedule-based data transmission; and (II) it differentiates the types of data transmission on the basis of data content and adopts different acknowledgment methods for different transmission types. To the best of our knowledge, no transport layer protocols have yet been designed for CRSNs. Simulation results show that the proposed protocol achieves remarkably longer network lifetime and shorter event-detection delay compared to those achieved with a conventional transport protocol, while simultaneously preserving event-detection reliability. PMID:25333288

ATM QoS Experiments Using TCP Applications: Performance of TCP/IP Over ATM in a Variety of Errored Links

NASA Technical Reports Server (NTRS)

Frantz, Brian D.; Ivancic, William D.

2001-01-01

Asynchronous Transfer Mode (ATM) Quality of Service (QoS) experiments using the Transmission Control Protocol/Internet Protocol (TCP/IP) were performed for various link delays. The link delay was set to emulate a Wide Area Network (WAN) and a Satellite Link. The purpose of these experiments was to evaluate the ATM QoS requirements for applications that utilize advance TCP/IP protocols implemented with large windows and Selective ACKnowledgements (SACK). The effects of cell error, cell loss, and random bit errors on throughput were reported. The detailed test plan and test results are presented herein.

An Energy Balanced and Lifetime Extended Routing Protocol for Underwater Sensor Networks.

PubMed

Wang, Hao; Wang, Shilian; Zhang, Eryang; Lu, Luxi

2018-05-17

Energy limitation is an adverse problem in designing routing protocols for underwater sensor networks (UWSNs). To prolong the network lifetime with limited battery power, an energy balanced and efficient routing protocol, called energy balanced and lifetime extended routing protocol (EBLE), is proposed in this paper. The proposed EBLE not only balances traffic loads according to the residual energy, but also optimizes data transmissions by selecting low-cost paths. Two phases are operated in the EBLE data transmission process: (1) candidate forwarding set selection phase and (2) data transmission phase. In candidate forwarding set selection phase, nodes update candidate forwarding nodes by broadcasting the position and residual energy level information. The cost value of available nodes is calculated and stored in each sensor node. Then in data transmission phase, high residual energy and relatively low-cost paths are selected based on the cost function and residual energy level information. We also introduce detailed analysis of optimal energy consumption in UWSNs. Numerical simulation results on a variety of node distributions and data load distributions prove that EBLE outperforms other routing protocols (BTM, BEAR and direct transmission) in terms of network lifetime and energy efficiency.

Distributed Topology Organization and Transmission Scheduling in Wireless Ad Hoc Networks

DTIC Science & Technology

2004-01-01

slot consists of two mini -slots that support that support full-duplex transfer–one for master-to-slave transmission and the other from slave-to-master...protocol storage requirement would only be 208 bits in this case. 111 Communication requirements Each half-duplex mini -slot can be used by either a data or...either a data or control packet, eq. (4.2) sets the minimum half-duplex mini -slot size in the system or equivalently, the maximum system period

Direct counterfactual transmission of a quantum state

NASA Astrophysics Data System (ADS)

Li, Zheng-Hong; Al-Amri, M.; Zubairy, M. Suhail

2015-11-01

We show that an unknown quantum state can be transferred with neither quantum nor classical particle traveling in the transmission channel. Our protocol does not require prearranged entangled photon pairs and Bell measurements. By utilizing quantum Zeno effect and counterfactuality, we can entangle and disentangle a photon and an atom by nonlocal interaction. It is shown that quantum information is completely transferred from an atom to photon due to controllable disentanglement processes. There is no need to cross-check the result via classical channels.

A Comparative Analysis of Transmission Control Protocol Improvement Techniques over Space-Based Transmission Media

DTIC Science & Technology

2006-03-01

utilized; for normality, the Shapiro-Wilk test ; and finally, for constant variance the Breusch - Pagan test was used. The Durbin-Watson test results...against this violation, it is of concern with respect to the validity of this model. In order to execute Breusch - Pagan test , it is necessary to obtain...a SSE of 23,297.73. The ρ-value for the Breusch - Pagan test was obtained via use of a spreadsheet program (Microsoft’s Excel) and the expression

[Young women with HIV infection acquired by vertical transmission: Expectations of having uninfected children].

PubMed

Villarroel, Julia; Álvarez, Ana M; Salvador, Francisco; Chávez, Ana; Wu, Elba; Contardo, Verónica

2016-12-01

Pediatric antiretroviral therapy (ART), changed the prognosis of the disease, allowing young women infected by vertical transmission (TV) to be pregnant without risk for their fetus of acquiring this infection. To describe the clinical-immune status in pregnant women that acquired HV by vertical transmission, treatments received, monitoring of pregnancy and newborn characteristics. A protocol was performed, evaluating clinical and immunological parameters during pregnancy, ART used, protocol preventing vertical transmission (PPTV), and follow up of children to 18 months of age. Of 358 HIV-positive patients vertically infected, five women became pregnant, between 14 and 24 years old. Pregnancies were controlled in clinical/immune-stage N2 C3. They had received two to five therapies. Full PPTV was performed in all binomials. Pre-natal undetectable viral loads ranged from 4,700 ARN copies/mL. Five living children were born by Caesarean section, four of them with 37 weeks of completed gestation and one of them with 34 weeks of gestation. All received zidovudine (AZT) for 6 weeks. CD4 at 72 hours of life ranged from 48% to 74.6%. All children were born uninfected with HIV. Only two had mild anemia. Expectations of HIV mothers vertically infected to have healthy children are similar to those infected by horizontal transmission, using PPTV.

Finite-Horizon $H_\\infty $ Consensus for Multiagent Systems With Redundant Channels via An Observer-Type Event-Triggered Scheme.

PubMed

Xu, Wenying; Wang, Zidong; Ho, Daniel W C

2018-05-01

This paper is concerned with the finite-horizon consensus problem for a class of discrete time-varying multiagent systems with external disturbances and missing measurements. To improve the communication reliability, redundant channels are introduced and the corresponding protocol is constructed for the information transmission over redundant channels. An event-triggered scheme is adopted to determine whether the information of agents should be transmitted to their neighbors. Subsequently, an observer-type event-triggered control protocol is proposed based on the latest received neighbors' information. The purpose of the addressed problem is to design a time-varying controller based on the observed information to achieve the consensus performance in a finite horizon. By utilizing a constrained recursive Riccati difference equation approach, some sufficient conditions are obtained to guarantee the consensus performance, and the controller parameters are also designed. Finally, a numerical example is provided to demonstrate the desired reliability of redundant channels and the effectiveness of the event-triggered control protocol.

Privacy Preserving Quantum Anonymous Transmission via Entanglement Relay

NASA Astrophysics Data System (ADS)

Yang, Wei; Huang, Liusheng; Song, Fang

2016-06-01

Anonymous transmission is an interesting and crucial issue in computer communication area, which plays a supplementary role to data privacy. In this paper, we put forward a privacy preserving quantum anonymous transmission protocol based on entanglement relay, which constructs anonymous entanglement from EPR pairs instead of multi-particle entangled state, e.g. GHZ state. Our protocol achieves both sender anonymity and receiver anonymity against an active adversary and tolerates any number of corrupt participants. Meanwhile, our protocol obtains an improvement in efficiency compared to quantum schemes in previous literature.

Privacy Preserving Quantum Anonymous Transmission via Entanglement Relay.

PubMed

Yang, Wei; Huang, Liusheng; Song, Fang

2016-06-01

Anonymous transmission is an interesting and crucial issue in computer communication area, which plays a supplementary role to data privacy. In this paper, we put forward a privacy preserving quantum anonymous transmission protocol based on entanglement relay, which constructs anonymous entanglement from EPR pairs instead of multi-particle entangled state, e.g. GHZ state. Our protocol achieves both sender anonymity and receiver anonymity against an active adversary and tolerates any number of corrupt participants. Meanwhile, our protocol obtains an improvement in efficiency compared to quantum schemes in previous literature.

Privacy Preserving Quantum Anonymous Transmission via Entanglement Relay

PubMed Central

Yang, Wei; Huang, Liusheng; Song, Fang

2016-01-01

Anonymous transmission is an interesting and crucial issue in computer communication area, which plays a supplementary role to data privacy. In this paper, we put forward a privacy preserving quantum anonymous transmission protocol based on entanglement relay, which constructs anonymous entanglement from EPR pairs instead of multi-particle entangled state, e.g. GHZ state. Our protocol achieves both sender anonymity and receiver anonymity against an active adversary and tolerates any number of corrupt participants. Meanwhile, our protocol obtains an improvement in efficiency compared to quantum schemes in previous literature. PMID:27247078

Energy transmission using recyclable quantum entanglement

PubMed Central

Ye, Ming-Yong; Lin, Xiu-Min

2016-01-01

It is known that faster-than-light (FTL) transmission of energy could be achieved if the transmission were considered in the framework of non-relativistic classical mechanics. Here we show that FTL transmission of energy could also be achieved if the transmission were considered in the framework of non-relativistic quantum mechanics. In our transmission protocol a two-spin Heisenberg model is considered and the energy is transmitted by two successive local unitary operations on the initially entangled spins. Our protocol does not mean that FTL transmission can be achieved in reality when the theory of relativity is considered, but it shows that quantum entanglement can be used in a recyclable way in energy transmission. PMID:27465431

Mycobacterium tuberculosis Infection among Asian Elephants in Captivity.

PubMed

Simpson, Gary; Zimmerman, Ralph; Shashkina, Elena; Chen, Liang; Richard, Michael; Bradford, Carol M; Dragoo, Gwen A; Saiers, Rhonda L; Peloquin, Charles A; Daley, Charles L; Planet, Paul; Narachenia, Apurva; Mathema, Barun; Kreiswirth, Barry N

2017-03-01

Although awareness of tuberculosis among captive elephants is increasing, antituberculosis therapy for these animals is not standardized. We describe Mycobacterium tuberculosis transmission between captive elephants based on whole genome analysis and report a successful combination treatment. Infection control protocols and careful monitoring of treatment of captive elephants with tuberculosis are warranted.

Repeated arterial occlusion, delta-opioid receptor (DOR) plasticity and vagal transmission within the sinoatrial node of the anesthetized dog.

PubMed

Deo, Shekhar H; Barlow, Matthew A; Gonzalez, Leticia; Yoshishige, Darice; Caffrey, James L

2009-01-01

Brief interruptions in coronary blood flow precondition the heart, engage delta-opioid receptor (DOR) mechanisms and reduce the damage that typically accompanies subsequent longer coronary occlusions. Repeated short occlusions of the sinoatrial (SA) node artery progressively raised nodal methionine-enkephalin-arginine-phenylalanine (MEAP) and improved vagal transmission during subsequent long occlusions in anesthetized dogs. The DOR type-1 (DOR-1) antagonist, BNTX reversed the vagotonic effect. Higher doses of enkephalin interrupted vagal transmission through a DOR-2 mechanism. The current study tested whether the preconditioning (PC) protocol, the later occlusion or a combination of both was required for the vagotonic effect. The study also tested whether evolving vagotonic effects included withdrawal of competing DOR-2 vagolytic influences. Vagal transmission progressively improved during successive SA nodal artery occlusions. The vagotonic effect was absent in sham animals and after DOR-1 blockade. After completing the PC protocol, exogenously applied vagolytic doses of MEAP reduced vagal transmission under both normal and occluded conditions. The magnitude of these DOR-2 vagolytic effects was small compared to controls and repeated MEAP challenges rapidly eroded vagolytic responses further. Prior DOR-1 blockade did not alter the PC mediated, progressive loss of DOR-2 vagolytic responses. In conclusion, DOR-1 vagotonic responses evolved from signals earlier in the PC protocol and erosion of competing DOR-2 vagolytic responses may have contributed to an unmasking of vagotonic responses. The data support the hypothesis that PC and DOR-2 stimulation promote DOR trafficking, and down regulation of the vagolytic DOR-2 phenotype in favor of the vagotonic DOR-1 phenotype. DOR-1 blockade may accelerate the process by sequestering newly emerging receptors.

Advertisement-Based Energy Efficient Medium Access Protocols for Wireless Sensor Networks

NASA Astrophysics Data System (ADS)

Ray, Surjya Sarathi

One of the main challenges that prevents the large-scale deployment of Wireless Sensor Networks (WSNs) is providing the applications with the required quality of service (QoS) given the sensor nodes' limited energy supplies. WSNs are an important tool in supporting applications ranging from environmental and industrial monitoring, to battlefield surveillance and traffic control, among others. Most of these applications require sensors to function for long periods of time without human intervention and without battery replacement. Therefore, energy conservation is one of the main goals for protocols for WSNs. Energy conservation can be performed in different layers of the protocol stack. In particular, as the medium access control (MAC) layer can access and control the radio directly, large energy savings is possible through intelligent MAC protocol design. To maximize the network lifetime, MAC protocols for WSNs aim to minimize idle listening of the sensor nodes, packet collisions, and overhearing. Several approaches such as duty cycling and low power listening have been proposed at the MAC layer to achieve energy efficiency. In this thesis, I explore the possibility of further energy savings through the advertisement of data packets in the MAC layer. In the first part of my research, I propose Advertisement-MAC or ADV-MAC, a new MAC protocol for WSNs that utilizes the concept of advertising for data contention. This technique lets nodes listen dynamically to any desired transmission and sleep during transmissions not of interest. This minimizes the energy lost in idle listening and overhearing while maintaining an adaptive duty cycle to handle variable loads. Additionally, ADV-MAC enables energy efficient MAC-level multicasting. An analytical model for the packet delivery ratio and the energy consumption of the protocol is also proposed. The analytical model is verified with simulations and is used to choose an optimal value of the advertisement period. Simulations show that the optimized ADV-MAC provides substantial energy gains (50% to 70% less than other MAC protocols for WSNs such as T-MAC and S-MAC for the scenarios investigated) while faring as well as T-MAC in terms of packet delivery ratio and latency. Although ADV-MAC provides substantial energy gains over S-MAC and T-MAC, it is not optimal in terms of energy savings because contention is done twice -- once in the Advertisement Period and once in the Data Period. In the next part of my research, the second contention in the Data Period is eliminated and the advantages of contention-based and TDMA-based protocols are combined to form Advertisement based Time-division Multiple Access (ATMA), a distributed TDMA-based MAC protocol for WSNs. ATMA utilizes the bursty nature of the traffic to prevent energy waste through advertisements and reservations for data slots. Extensive simulations and qualitative analysis show that with bursty traffic, ATMA outperforms contention-based protocols (S-MAC, T-MAC and ADV-MAC), a TDMA based protocol (TRAMA) and hybrid protocols (Z-MAC and IEEE 802.15.4). ATMA provides energy reductions of up to 80%, while providing the best packet delivery ratio (close to 100%) and latency among all the investigated protocols. Simulations alone cannot reflect many of the challenges faced by real implementations of MAC protocols, such as clock-drift, synchronization, imperfect physical layers, and irregular interference from other transmissions. Such issues may cripple a protocol that otherwise performs very well in software simulations. Hence, to validate my research, I conclude with a hardware implementation of the ATMA protocol on SORA (Software Radio), developed by Microsoft Research Asia. SORA is a reprogrammable Software Defined Radio (SDR) platform that satisfies the throughput and timing requirements of modern wireless protocols while utilizing the rich general purpose PC development environment. Experimental results obtained from the hardware implementation of ATMA closely mirror the simulation results obtained for a single hop network with 4 nodes.

Interactive MPEG-4 low-bit-rate speech/audio transmission over the Internet

NASA Astrophysics Data System (ADS)

Liu, Fang; Kim, JongWon; Kuo, C.-C. Jay

1999-11-01

The recently developed MPEG-4 technology enables the coding and transmission of natural and synthetic audio-visual data in the form of objects. In an effort to extend the object-based functionality of MPEG-4 to real-time Internet applications, architectural prototypes of multiplex layer and transport layer tailored for transmission of MPEG-4 data over IP are under debate among Internet Engineering Task Force (IETF), and MPEG-4 systems Ad Hoc group. In this paper, we present an architecture for interactive MPEG-4 speech/audio transmission system over the Internet. It utilities a framework of Real Time Streaming Protocol (RTSP) over Real-time Transport Protocol (RTP) to provide controlled, on-demand delivery of real time speech/audio data. Based on a client-server model, a couple of low bit-rate bit streams (real-time speech/audio, pre- encoded speech/audio) are multiplexed and transmitted via a single RTP channel to the receiver. The MPEG-4 Scene Description (SD) and Object Descriptor (OD) bit streams are securely sent through the RTSP control channel. Upon receiving, an initial MPEG-4 audio- visual scene is constructed after de-multiplexing, decoding of bit streams, and scene composition. A receiver is allowed to manipulate the initial audio-visual scene presentation locally, or interactively arrange scene changes by sending requests to the server. A server may also choose to update the client with new streams and list of contents for user selection.

An Energy Efficient MAC Protocol for Multi-Hop Swallowable Body Sensor Networks

PubMed Central

Lin, Lin; Yang, Chengfeng; Wong, Kai Juan; Yan, Hao; Shen, Junwen; Phee, Soo Jay

2014-01-01

Swallowable body sensor networks (BSNs) are composed of sensors which are swallowed by patients and send the collected data to the outside coordinator. These sensors are energy constraint and the batteries are difficult to be replaced. The medium access control (MAC) protocol plays an important role in energy management. This paper investigates an energy efficient MAC protocol design for swallowable BSNs. Multi-hop communication is analyzed and proved more energy efficient than single-hop communication within the human body when the circuitry power is low. Based on this result, a centrally controlled time slotting schedule is proposed. The major workload is shifted from the sensors to the coordinator. The coordinator collects the path-loss map and calculates the schedules, including routing, slot assignment and transmission power. Sensor nodes follow the schedules to send data in a multi-hop way. The proposed protocol is compared with the IEEE 802.15.6 protocol in terms of energy consumption. The results show that it is more energy efficient than IEEE 802.15.6 for swallowable BSN scenarios. PMID:25330049

Adaptive transmission based on multi-relay selection and rate-compatible LDPC codes

NASA Astrophysics Data System (ADS)

Su, Hualing; He, Yucheng; Zhou, Lin

2017-08-01

In order to adapt to the dynamical changeable channel condition and improve the transmissive reliability of the system, a cooperation system of rate-compatible low density parity check (RC-LDPC) codes combining with multi-relay selection protocol is proposed. In traditional relay selection protocol, only the channel state information (CSI) of source-relay and the CSI of relay-destination has been considered. The multi-relay selection protocol proposed by this paper takes the CSI between relays into extra account in order to obtain more chances of collabration. Additionally, the idea of hybrid automatic request retransmission (HARQ) and rate-compatible are introduced. Simulation results show that the transmissive reliability of the system can be significantly improved by the proposed protocol.

(abstract) Experimental Results From Internetworking Data Applications Over Various Wireless Networks Using a Single Flexible Error Control Protocol

NASA Technical Reports Server (NTRS)

Kanai, T.; Kramer, M.; McAuley, A. J.; Nowack, S.; Pinck, D. S.; Ramirez, G.; Stewart, I.; Tohme, H.; Tong, L.

1995-01-01

This paper describes results from several wireless field trials in New Jersey, California, and Colorado, conducted jointly by researchers at Bellcore, JPL, and US West over the course of 1993 and 1994. During these trials, applications communicated over multiple wireless networks including satellite, low power PCS, high power cellular, packet data, and the wireline Public Switched Telecommunications Network (PSTN). Key goals included 1) designing data applications and an API suited to mobile users, 2) investigating internetworking issues, 3) characterizing wireless networks under various field conditions, and 4) comparing the performance of different protocol mechanisms over the diverse networks and applications. We describe experimental results for different protocol mechanisms and parameters, such as acknowledgment schemes and packet sizes. We show the need for powerful error control mechanisms such as selective acknowledgements and combining data from multiple transmissions. We highlight the possibility of a common protocol for all wireless networks, from micro-cellular PCS to satellite networks.

Squeezed-state quantum key distribution with a Rindler observer

NASA Astrophysics Data System (ADS)

Zhou, Jian; Shi, Ronghua; Guo, Ying

2018-03-01

Lengthening the maximum transmission distance of quantum key distribution plays a vital role in quantum information processing. In this paper, we propose a directional squeezed-state protocol with signals detected by a Rindler observer in the relativistic quantum field framework. We derive an analytical solution to the transmission problem of squeezed states from the inertial sender to the accelerated receiver. The variance of the involved signal mode is closer to optimality than that of the coherent-state-based protocol. Simulation results show that the proposed protocol has better performance than the coherent-state counterpart especially in terms of the maximal transmission distance.

High-Speed TCP Testing

NASA Technical Reports Server (NTRS)

Brooks, David E.; Gassman, Holly; Beering, Dave R.; Welch, Arun; Hoder, Douglas J.; Ivancic, William D.

1999-01-01

Transmission Control Protocol (TCP) is the underlying protocol used within the Internet for reliable information transfer. As such, there is great interest to have all implementations of TCP efficiently interoperate. This is particularly important for links exhibiting long bandwidth-delay products. The tools exist to perform TCP analysis at low rates and low delays. However, for extremely high-rate and lone-delay links such as 622 Mbps over geosynchronous satellites, new tools and testing techniques are required. This paper describes the tools and techniques used to analyze and debug various TCP implementations over high-speed, long-delay links.

Multi-Hop Teleportation of an Unknown Qubit State Based on W States

NASA Astrophysics Data System (ADS)

Zhou, Xiang-Zhen; Yu, Xu-Tao; Zhang, Zai-Chen

2018-04-01

Quantum teleportation is important in quantum communication networks. Considering that quantum state information is also transmitted between two distant nodes, intermediated nodes are employed and two multi-hop teleportation protocols based on W state are proposed. One is hop-by-hop teleportation protocol and the other is the improved multi-hop teleportation protocol with centralized unitary transformation. In hop-by-hop protocol, the transmitted quantum state needs to be recovered at every node on the route. In improved multi-hop teleportation protocol with centralized unitary transformation, intermediate nodes need not to recover the transmitted quantum state. Compared to the hop-by-hop protocol, the improved protocol can reduce the transmission delay and improve the transmission efficiency.

Coherent population trapping with a controlled dissipation: applications in optical metrology

NASA Astrophysics Data System (ADS)

Nicolas, L.; Delord, T.; Jamonneau, P.; Coto, R.; Maze, J.; Jacques, V.; Hétet, G.

2018-03-01

We analyze the properties of a pulsed coherent population trapping protocol that uses a controlled decay from the excited state in a Λ-level scheme. We study this problem analytically and numerically and find regimes where narrow transmission, absorption, or fluorescence spectral lines occur. We then look for optimal frequency measurements using these spectral features by computing the Allan deviation in the presence of ground state decoherence and show that the protocol is on a par with Ramsey-CPT. We discuss possible implementations with ensembles of alkali atoms and single ions and demonstrate that typical pulsed-CPT experiments that are realized on femto-second timescales can be implemented on micro-seconds timescales using this scheme.

Protocol to Exploit Waiting Resources for UASNs.

PubMed

Hung, Li-Ling; Luo, Yung-Jeng

2016-03-08

The transmission speed of acoustic waves in water is much slower than that of radio waves in terrestrial wireless sensor networks. Thus, the propagation delay in underwater acoustic sensor networks (UASN) is much greater. Longer propagation delay leads to complicated communication and collision problems. To solve collision problems, some studies have proposed waiting mechanisms; however, long waiting mechanisms result in low bandwidth utilization. To improve throughput, this study proposes a slotted medium access control protocol to enhance bandwidth utilization in UASNs. The proposed mechanism increases communication by exploiting temporal and spatial resources that are typically idle in order to protect communication against interference. By reducing wait time, network performance and energy consumption can be improved. A performance evaluation demonstrates that when the data packets are large or sensor deployment is dense, the energy consumption of proposed protocol is less than that of existing protocols as well as the throughput is higher than that of existing protocols.

Symbolic and Sub-Symbolic Robotic Intelligence Control System (SS-RICS) Users Manual

DTIC Science & Technology

2017-10-01

platform and simulators via either a serial or Transmission Control Protocol (TCP)/IP connection. The implementation of SS-RICS was designed and...box 4.2 SubSim Config Dialog This interface (Fig. 22) is designed to provide execution and property control of all of the subsimprocessors... post fixed with a “_” to designate the end of the variable (e.g., $Line1_memory was found). Example: rTestDollarSign { (* $LookType Distance

Developing a Video-Based eHealth Intervention for HIV-Positive Gay, Bisexual, and Other Men Who Have Sex with Men: Study Protocol for a Randomized Controlled Trial.

PubMed

Hirshfield, Sabina; Downing, Martin J; Parsons, Jeffrey T; Grov, Christian; Gordon, Rachel J; Houang, Steven T; Scheinmann, Roberta; Sullivan, Patrick S; Yoon, Irene S; Anderson, Ian; Chiasson, Mary Ann

2016-06-17

Gay, bisexual, and other men who have sex with men (GBMSM) accounted for 67% of new US human immunodeficiency virus (HIV) infections in 2012; however, less than 40% of HIV-positive GBMSM are virally suppressed. Preventing transmission from virally unsuppressed men who have condomless anal sex (CAS) with serodiscordant partners is a public health imperative. New HIV infections in GBMSM are attributed in part to online access to sex partners; therefore, low-cost eHealth interventions are a unique opportunity to reach men where they meet partners. To describe the protocol of a randomized controlled trial evaluating whether video-based messaging delivered online may lead to reductions in serodiscordant CAS and increased HIV disclosure. Sex Positive!([+]) is a two-arm, phase III, video-based randomized controlled trial delivered online to GBMSM living with HIV. Participants in the intervention arm receive 10 video vignettes grounded in social learning and social cognitive theories that are designed to elicit critical thinking around issues of HIV transmission and disclosure. Participants in the attention control arm receive 10 video vignettes that focus on healthy living. All videos are optimized for mobile viewing. The study protocol includes five online assessments conducted over a 1-year period among 1500 US white, black, or Hispanic/Latino GBMSM living with HIV who report suboptimal antiretroviral therapy (ART) adherence or a detectable viral load in the past 12 months and recent CAS (past 6 months) with HIV-negative or unknown status male partners. Compared to the control arm, we hypothesize that men who watch the intervention videos will report at 12-month follow-up significantly fewer serodiscordant CAS partners, increased HIV disclosure, and improved social cognition (eg, condom use self-efficacy, perceived responsibility). Participant recruitment began in June 2015 and ended in December 2015. This protocol describes the underlying theoretical framework and measures, study design, recruitment challenges, and antifraud measures for an online, video-based randomized controlled trial that has the potential to decrease HIV transmission risk behaviors among HIV-positive GBMSM who struggle with ART adherence. The Sex Positive!([+]) intervention allows for participation through multiple Internet-based mediums and has the potential to reach and engage a broader population of HIV-positive GBMSM who are virally unsuppressed. ClinicalTrials.gov NCT02023580; https://clinicaltrials.gov/ct2/show/NCT02023580 (Archived by WebCite at http://www.webcitation.org/6iHzA8wRG).

Developing a Video-Based eHealth Intervention for HIV-Positive Gay, Bisexual, and Other Men Who Have Sex with Men: Study Protocol for a Randomized Controlled Trial

PubMed Central

Downing Jr, Martin J; Parsons, Jeffrey T; Grov, Christian; Gordon, Rachel J; Houang, Steven T; Scheinmann, Roberta; Sullivan, Patrick S; Yoon, Irene S; Anderson, Ian; Chiasson, Mary Ann

2016-01-01

Background Gay, bisexual, and other men who have sex with men (GBMSM) accounted for 67% of new US human immunodeficiency virus (HIV) infections in 2012; however, less than 40% of HIV-positive GBMSM are virally suppressed. Preventing transmission from virally unsuppressed men who have condomless anal sex (CAS) with serodiscordant partners is a public health imperative. New HIV infections in GBMSM are attributed in part to online access to sex partners; therefore, low-cost eHealth interventions are a unique opportunity to reach men where they meet partners. Objective To describe the protocol of a randomized controlled trial evaluating whether video-based messaging delivered online may lead to reductions in serodiscordant CAS and increased HIV disclosure. Methods Sex Positive![+] is a two-arm, phase III, video-based randomized controlled trial delivered online to GBMSM living with HIV. Participants in the intervention arm receive 10 video vignettes grounded in social learning and social cognitive theories that are designed to elicit critical thinking around issues of HIV transmission and disclosure. Participants in the attention control arm receive 10 video vignettes that focus on healthy living. All videos are optimized for mobile viewing. The study protocol includes five online assessments conducted over a 1-year period among 1500 US white, black, or Hispanic/Latino GBMSM living with HIV who report suboptimal antiretroviral therapy (ART) adherence or a detectable viral load in the past 12 months and recent CAS (past 6 months) with HIV-negative or unknown status male partners. Compared to the control arm, we hypothesize that men who watch the intervention videos will report at 12-month follow-up significantly fewer serodiscordant CAS partners, increased HIV disclosure, and improved social cognition (eg, condom use self-efficacy, perceived responsibility). Results Participant recruitment began in June 2015 and ended in December 2015. Conclusions This protocol describes the underlying theoretical framework and measures, study design, recruitment challenges, and antifraud measures for an online, video-based randomized controlled trial that has the potential to decrease HIV transmission risk behaviors among HIV-positive GBMSM who struggle with ART adherence. The Sex Positive![+] intervention allows for participation through multiple Internet-based mediums and has the potential to reach and engage a broader population of HIV-positive GBMSM who are virally unsuppressed. ClinicalTrial ClinicalTrials.gov NCT02023580; https://clinicaltrials.gov/ct2/show/NCT02023580 (Archived by WebCite at http://www.webcitation.org/6iHzA8wRG) PMID:27315764

A New Cellular Architecture for Information Retrieval from Sensor Networks through Embedded Service and Security Protocols

PubMed Central

Shahzad, Aamir; Landry, René; Lee, Malrey; Xiong, Naixue; Lee, Jongho; Lee, Changhoon

2016-01-01

Substantial changes have occurred in the Information Technology (IT) sectors and with these changes, the demand for remote access to field sensor information has increased. This allows visualization, monitoring, and control through various electronic devices, such as laptops, tablets, i-Pads, PCs, and cellular phones. The smart phone is considered as a more reliable, faster and efficient device to access and monitor industrial systems and their corresponding information interfaces anywhere and anytime. This study describes the deployment of a protocol whereby industrial system information can be securely accessed by cellular phones via a Supervisory Control And Data Acquisition (SCADA) server. To achieve the study goals, proprietary protocol interconnectivity with non-proprietary protocols and the usage of interconnectivity services are considered in detail. They support the visualization of the SCADA system information, and the related operations through smart phones. The intelligent sensors are configured and designated to process real information via cellular phones by employing information exchange services between the proprietary protocol and non-proprietary protocols. SCADA cellular access raises the issue of security flaws. For these challenges, a cryptography-based security method is considered and deployed, and it could be considered as a part of a proprietary protocol. Subsequently, transmission flows from the smart phones through a cellular network. PMID:27314351

A New Cellular Architecture for Information Retrieval from Sensor Networks through Embedded Service and Security Protocols.

PubMed

Shahzad, Aamir; Landry, René; Lee, Malrey; Xiong, Naixue; Lee, Jongho; Lee, Changhoon

2016-06-14

Substantial changes have occurred in the Information Technology (IT) sectors and with these changes, the demand for remote access to field sensor information has increased. This allows visualization, monitoring, and control through various electronic devices, such as laptops, tablets, i-Pads, PCs, and cellular phones. The smart phone is considered as a more reliable, faster and efficient device to access and monitor industrial systems and their corresponding information interfaces anywhere and anytime. This study describes the deployment of a protocol whereby industrial system information can be securely accessed by cellular phones via a Supervisory Control And Data Acquisition (SCADA) server. To achieve the study goals, proprietary protocol interconnectivity with non-proprietary protocols and the usage of interconnectivity services are considered in detail. They support the visualization of the SCADA system information, and the related operations through smart phones. The intelligent sensors are configured and designated to process real information via cellular phones by employing information exchange services between the proprietary protocol and non-proprietary protocols. SCADA cellular access raises the issue of security flaws. For these challenges, a cryptography-based security method is considered and deployed, and it could be considered as a part of a proprietary protocol. Subsequently, transmission flows from the smart phones through a cellular network.

Mycobacterium tuberculosis Infection among Asian Elephants in Captivity

PubMed Central

Simpson, Gary; Zimmerman, Ralph; Shashkina, Elena; Chen, Liang; Richard, Michael; Bradford, Carol M.; Dragoo, Gwen A.; Saiers, Rhonda L.; Peloquin, Charles A.; Daley, Charles L.; Planet, Paul; Narachenia, Apurva; Mathema, Barun

2017-01-01

Although awareness of tuberculosis among captive elephants is increasing, antituberculosis therapy for these animals is not standardized. We describe Mycobacterium tuberculosis transmission between captive elephants based on whole genome analysis and report a successful combination treatment. Infection control protocols and careful monitoring of treatment of captive elephants with tuberculosis are warranted. PMID:28221115

Three days of intermittent stretching after muscle disuse alters the proteins involved in force transmission in muscle fibers in weanling rats

PubMed Central

Gianelo, M.C.S.; Polizzelo, J.C.; Chesca, D.; Mattiello-Sverzut, A.C.

2015-01-01

The aim of this study was to determine the effects of intermittent passive manual stretching on various proteins involved in force transmission in skeletal muscle. Female Wistar weanling rats were randomly assigned to 5 groups: 2 control groups containing 21- and 30-day-old rats that received neither immobilization nor stretching, and 3 test groups that received 1) passive stretching over 3 days, 2) immobilization for 7 days and then passive stretching over 3 days, or 3) immobilization for 7 days. Maximal plantar flexion in the right hind limb was imposed, and the stretching protocol of 10 repetitions of 30 s stretches was applied. The soleus muscles were harvested and processed for HE and picrosirius staining; immunohistochemical analysis of collagen types I, III, IV, desmin, and vimentin; and immunofluorescence labeling of dystrophin and CD68. The numbers of desmin- and vimentin-positive cells were significantly decreased compared with those in the control following immobilization, regardless of whether stretching was applied (P<0.05). In addition, the semi-quantitative analysis showed that collagen type I was increased and type IV was decreased in the immobilized animals, regardless of whether the stretching protocol was applied. In conclusion, the largest changes in response to stretching were observed in muscles that had been previously immobilized, and the stretching protocol applied here did not mitigate the immobilization-induced muscle changes. Muscle disuse adversely affected several proteins involved in the transmission of forces between the intracellular and extracellular compartments. Thus, the 3-day rehabilitation period tested here did not provide sufficient time for the muscles to recover from the disuse maladaptations in animals undergoing postnatal development. PMID:26648091

Three days of intermittent stretching after muscle disuse alters the proteins involved in force transmission in muscle fibers in weanling rats.

PubMed

Gianelo, M C S; Polizzelo, J C; Chesca, D; Mattiello-Sverzut, A C

2016-02-01

The aim of this study was to determine the effects of intermittent passive manual stretching on various proteins involved in force transmission in skeletal muscle. Female Wistar weanling rats were randomly assigned to 5 groups: 2 control groups containing 21- and 30-day-old rats that received neither immobilization nor stretching, and 3 test groups that received 1) passive stretching over 3 days, 2) immobilization for 7 days and then passive stretching over 3 days, or 3) immobilization for 7 days. Maximal plantar flexion in the right hind limb was imposed, and the stretching protocol of 10 repetitions of 30 s stretches was applied. The soleus muscles were harvested and processed for HE and picrosirius staining; immunohistochemical analysis of collagen types I, III, IV, desmin, and vimentin; and immunofluorescence labeling of dystrophin and CD68. The numbers of desmin- and vimentin-positive cells were significantly decreased compared with those in the control following immobilization, regardless of whether stretching was applied (P<0.05). In addition, the semi-quantitative analysis showed that collagen type I was increased and type IV was decreased in the immobilized animals, regardless of whether the stretching protocol was applied. In conclusion, the largest changes in response to stretching were observed in muscles that had been previously immobilized, and the stretching protocol applied here did not mitigate the immobilization-induced muscle changes. Muscle disuse adversely affected several proteins involved in the transmission of forces between the intracellular and extracellular compartments. Thus, the 3-day rehabilitation period tested here did not provide sufficient time for the muscles to recover from the disuse maladaptations in animals undergoing postnatal development.

Statistical performance evaluation of ECG transmission using wireless networks.

PubMed

Shakhatreh, Walid; Gharaibeh, Khaled; Al-Zaben, Awad

2013-07-01

This paper presents simulation of the transmission of biomedical signals (using ECG signal as an example) over wireless networks. Investigation of the effect of channel impairments including SNR, pathloss exponent, path delay and network impairments such as packet loss probability; on the diagnosability of the received ECG signal are presented. The ECG signal is transmitted through a wireless network system composed of two communication protocols; an 802.15.4- ZigBee protocol and an 802.11b protocol. The performance of the transmission is evaluated using higher order statistics parameters such as kurtosis and Negative Entropy in addition to the common techniques such as the PRD, RMS and Cross Correlation.

Real-time echocardiogram transmission protocol based on regions and visualization modes.

PubMed

Cavero, Eva; Alesanco, Álvaro; García, José

2014-09-01

This paper proposes an Echocardiogram Transmission Protocol (ETP) for real-time end-to-end transmission of echocardiograms over IP networks. The ETP has been designed taking into account the echocardiogram characteristics of each visualized region, encoding each region according to its data type, visualization characteristics and diagnostic importance in order to improve the coding and thus the transmission efficiency. Furthermore, each region is sent separately and different error protection techniques can be used for each region. This leads to an efficient use of resources and provides greater protection for those regions with more clinical information. Synchronization is implemented for regions that change over time. The echocardiogram composition is different for each device. The protocol is valid for all echocardiogram devices thanks to the incorporation of configuration information which includes the composition of the echocardiogram. The efficiency of the ETP has been proved in terms of the number of bits sent with the proposed protocol. The codec and transmission rates used for the regions of interest have been set according to previous recommendations. Although the saving in the codified bits depends on the video composition, a coding gain higher than 7% with respect to without using ETP has been achieved.

A Novel Scheme for Bidirectional and Hybrid Quantum Information Transmission via a Seven-Qubit State

NASA Astrophysics Data System (ADS)

Fang, Sheng-hui; Jiang, Min

2018-02-01

In this paper, we present a novel scheme for bidirectional and hybrid quantum information transmission via a seven-qubit state. We demonstrate that under the control of the supervisor two distant participants can simultaneously and deterministically exchange their states with each other no matter whether they know the states or not. In our scheme, Alice can teleport an arbitrary single-qubit state (two-qubit state) to Bob and Bob can prepare a known two-qubit state (single-qubit state) for Alice simultaneously via the control of the supervisor Charlie. Compared with previous studies for single bidirectional quantum teleportation or single bidirectional remote state preparation schemes, our protocol is a kind of hybrid approach for quantum information transmission. Furthermore, it achieves success with unit probability. Notably, since only pauli operations and two-qubit and single-qubit measurements are used in our schemes, it is flexible in physical experiments.

Laboratory activities involving transmissible spongiform encephalopathy causing agents

PubMed Central

Leunda, Amaya; Van Vaerenbergh, Bernadette; Baldo, Aline; Roels, Stefan; Herman, Philippe

2013-01-01

Since the appearance in 1986 of epidemic of bovine spongiform encephalopathy (BSE), a new form of neurological disease in cattle which also affected human beings, many diagnostic and research activities have been performed to develop detection and therapeutic tools. A lot of progress was made in better identifying, understanding and controlling the spread of the disease by appropriate monitoring and control programs in European countries. This paper reviews the recent knowledge on pathogenesis, transmission and persistence outside the host of prion, the causative agent of transmissible spongiform encephalopathies (TSE) in mammals with a particular focus on risk (re)assessment and management of biosafety measures to be implemented in diagnostic and research laboratories in Belgium. Also, in response to the need of an increasing number of European diagnostic laboratories stopping TSE diagnosis due to a decreasing number of TSE cases reported in the last years, decontamination procedures and a protocol for decommissioning TSE diagnostic laboratories is proposed. PMID:24055928

Transmission and reflection of charge-density wave packets in a quantum Hall edge controlled by a metal gate

NASA Astrophysics Data System (ADS)

Matsuura, Masahiro; Mano, Takaaki; Noda, Takeshi; Shibata, Naokazu; Hotta, Masahiro; Yusa, Go

2018-02-01

Quantum energy teleportation (QET) is a proposed protocol related to quantum vacuum. The edge channels in a quantum Hall system are well suited for the experimental verification of QET. For this purpose, we examine a charge-density wave packet excited and detected by capacitively coupled front gate electrodes. We observe the waveform of the charge packet, which is proportional to the time derivative of the applied square voltage wave. Further, we study the transmission and reflection behaviors of the charge-density wave packet by applying a voltage to another front gate electrode to control the path of the edge state. We show that the threshold voltages where the dominant direction is switched in either transmission or reflection for dense and sparse wave packets are different from the threshold voltage where the current stops flowing in an equilibrium state.

Advanced teleprocessing systems

NASA Astrophysics Data System (ADS)

Kleinrock, L.; Gerla, M.

1982-09-01

This Annual Technical Report covers research covering the period from October 1, 1981 to September 30, 1982. This contract has three primary designated research areas: packet radio systems, resource sharing and allocation, and distributed processing and control. This report contains abstracts of publications which summarize research results in these areas followed by the main body of the report which is devoted to a study of channel access protocols that are executed by the nodes of a network to schedule their transmissions on multi-access broadcast channel. In particular the main body consists of a Ph.D. dissertation, Channel Access Protocols for Multi-Hop Broadcast Packet Radio Networks. This work discusses some new channel access protocols useful for mobile radio networks. Included is an analysis of slotted ALOHA and some tight bounds on the performance of all possible protocols in a mobile environment.

Finite-Horizon H∞ Consensus Control of Time-Varying Multiagent Systems With Stochastic Communication Protocol.

PubMed

Zou, Lei; Wang, Zidong; Gao, Huijun; Alsaadi, Fuad E

2017-03-31

This paper is concerned with the distributed H∞ consensus control problem for a discrete time-varying multiagent system with the stochastic communication protocol (SCP). A directed graph is used to characterize the communication topology of the multiagent network. The data transmission between each agent and the neighboring ones is implemented via a constrained communication channel where only one neighboring agent is allowed to transmit data at each time instant. The SCP is applied to schedule the signal transmission of the multiagent system. A sequence of random variables is utilized to capture the scheduling behavior of the SCP. By using the mapping technology combined with the Hadamard product, the closed-loop multiagent system is modeled as a time-varying system with a stochastic parameter matrix. The purpose of the addressed problem is to design a cooperative controller for each agent such that, for all probabilistic scheduling behaviors, the H∞ consensus performance is achieved over a given finite horizon for the closed-loop multiagent system. A necessary and sufficient condition is derived to ensure the H∞ consensus performance based on the completing squares approach and the stochastic analysis technique. Then, the controller parameters are obtained by solving two coupled backward recursive Riccati difference equations. Finally, a numerical example is given to illustrate the effectiveness of the proposed controller design scheme.

The impact of hotspot-targeted interventions on malaria transmission: study protocol for a cluster-randomized controlled trial

PubMed Central

2013-01-01

Background Malaria transmission is highly heterogeneous in most settings, resulting in the formation of recognizable malaria hotspots. Targeting these hotspots might represent a highly efficacious way of controlling or eliminating malaria if the hotspots fuel malaria transmission to the wider community. Methods/design Hotspots of malaria will be determined based on spatial patterns in age-adjusted prevalence and density of antibodies against malaria antigens apical membrane antigen-1 and merozoite surface protein-1. The community effect of interventions targeted at these hotspots will be determined. The intervention will comprise larviciding, focal screening and treatment of the human population, distribution of long-lasting insecticide-treated nets and indoor residual spraying. The impact of the intervention will be determined inside and up to 500 m outside the targeted hotspots by PCR-based parasite prevalence in cross-sectional surveys, malaria morbidity by passive case detection in selected facilities and entomological monitoring of larval and adult Anopheles populations. Discussion This study aims to provide direct evidence for a community effect of hotspot-targeted interventions. The trial is powered to detect large effects on malaria transmission in the context of ongoing malaria interventions. Follow-up studies will be needed to determine the effect of individual components of the interventions and the cost-effectiveness of a hotspot-targeted approach, where savings made by reducing the number of compounds that need to receive interventions should outweigh the costs of hotspot-detection. Trial registration NCT01575613. The protocol was registered online on 20 March 2012; the first community was randomized on 26 March 2012. PMID:23374910

AURP: An AUV-Aided Underwater Routing Protocol for Underwater Acoustic Sensor Networks

PubMed Central

Yoon, Seokhoon; Azad, Abul K.; Oh, Hoon; Kim, Sunghwan

2012-01-01

Deploying a multi-hop underwater acoustic sensor network (UASN) in a large area brings about new challenges in reliable data transmissions and survivability of network due to the limited underwater communication range/bandwidth and the limited energy of underwater sensor nodes. In order to address those challenges and achieve the objectives of maximization of data delivery ratio and minimization of energy consumption of underwater sensor nodes, this paper proposes a new underwater routing scheme, namely AURP (AUV-aided underwater routing protocol), which uses not only heterogeneous acoustic communication channels but also controlled mobility of multiple autonomous underwater vehicles (AUVs). In AURP, the total data transmissions are minimized by using AUVs as relay nodes, which collect sensed data from gateway nodes and then forward to the sink. Moreover, controlled mobility of AUVs makes it possible to apply a short-range high data rate underwater channel for transmissions of a large amount of data. To the best to our knowledge, this work is the first attempt to employ multiple AUVs as relay nodes in a multi-hop UASN to improve the network performance in terms of data delivery ratio and energy consumption. Simulations, which are incorporated with a realistic underwater acoustic communication channel model, are carried out to evaluate the performance of the proposed scheme, and the results indicate that a high delivery ratio and low energy consumption can be achieved. PMID:22438740

AURP: an AUV-aided underwater routing protocol for underwater acoustic sensor networks.

PubMed

Yoon, Seokhoon; Azad, Abul K; Oh, Hoon; Kim, Sunghwan

2012-01-01

Deploying a multi-hop underwater acoustic sensor network (UASN) in a large area brings about new challenges in reliable data transmissions and survivability of network due to the limited underwater communication range/bandwidth and the limited energy of underwater sensor nodes. In order to address those challenges and achieve the objectives of maximization of data delivery ratio and minimization of energy consumption of underwater sensor nodes, this paper proposes a new underwater routing scheme, namely AURP (AUV-aided underwater routing protocol), which uses not only heterogeneous acoustic communication channels but also controlled mobility of multiple autonomous underwater vehicles (AUVs). In AURP, the total data transmissions are minimized by using AUVs as relay nodes, which collect sensed data from gateway nodes and then forward to the sink. Moreover, controlled mobility of AUVs makes it possible to apply a short-range high data rate underwater channel for transmissions of a large amount of data. To the best to our knowledge, this work is the first attempt to employ multiple AUVs as relay nodes in a multi-hop UASN to improve the network performance in terms of data delivery ratio and energy consumption. Simulations, which are incorporated with a realistic underwater acoustic communication channel model, are carried out to evaluate the performance of the proposed scheme, and the results indicate that a high delivery ratio and low energy consumption can be achieved.

Designing of routing algorithms in autonomous distributed data transmission system for mobile computing devices with ‘WiFi-Direct’ technology

NASA Astrophysics Data System (ADS)

Nikitin, I. A.; Sherstnev, V. S.; Sherstneva, A. I.; Botygin, I. A.

2017-02-01

The results of the research of existent routing protocols in wireless networks and their main features are discussed in the paper. Basing on the protocol data, the routing protocols in wireless networks, including search routing algorithms and phone directory exchange algorithms, are designed with the ‘WiFi-Direct’ technology. Algorithms without IP-protocol were designed, and that enabled one to increase the efficiency of the algorithms while working only with the MAC-addresses of the devices. The developed algorithms are expected to be used in the mobile software engineering with the Android platform taken as base. Easier algorithms and formats of the well-known route protocols, rejection of the IP-protocols enables to use the developed protocols on more primitive mobile devices. Implementation of the protocols to the engineering industry enables to create data transmission networks among working places and mobile robots without any access points.

A native Bayesian classifier based routing protocol for VANETS

NASA Astrophysics Data System (ADS)

Bao, Zhenshan; Zhou, Keqin; Zhang, Wenbo; Gong, Xiaolei

2016-12-01

Geographic routing protocols are one of the most hot research areas in VANET (Vehicular Ad-hoc Network). However, there are few routing protocols can take both the transmission efficient and the usage of ratio into account. As we have noticed, different messages in VANET may ask different quality of service. So we raised a Native Bayesian Classifier based routing protocol (Naive Bayesian Classifier-Greedy, NBC-Greedy), which can classify and transmit different messages by its emergency degree. As a result, we can balance the transmission efficient and the usage of ratio with this protocol. Based on Matlab simulation, we can draw a conclusion that NBC-Greedy is more efficient and stable than LR-Greedy and GPSR.

Mobile-ip Aeronautical Network Simulation Study

NASA Technical Reports Server (NTRS)

Ivancic, William D.; Tran, Diepchi T.

2001-01-01

NASA is interested in applying mobile Internet protocol (mobile-ip) technologies to its space and aeronautics programs. In particular, mobile-ip will play a major role in the Advanced Aeronautic Transportation Technology (AATT), the Weather Information Communication (WINCOMM), and the Small Aircraft Transportation System (SATS) aeronautics programs. This report presents the results of a simulation study of mobile-ip for an aeronautical network. The study was performed to determine the performance of the transmission control protocol (TCP) in a mobile-ip environment and to gain an understanding of how long delays, handoffs, and noisy channels affect mobile-ip performance.

BASALT Project Helps Develop Mars Science Protocols

NASA Image and Video Library

2016-11-18

Researchers from NASA Ames and the University of Hawaii - Hilo spent 18 days simulating science activities on the surface of Mars. Although no spacesuits were used, scientist hiked around Hawaii Volcanoes National Park on the Island of Hawaii and collected rock samples like they would on the Red Planet. One goal of the Biologic Analog Science Associated with Lava Terrains project is to develop rules and protocols that could be used on an actual Mars mission to identify and protect geologic samples that could contain life. Communications with a mission control room were delayed, to simulate actual transmission times between Earth and Mars.

Cross-layer model design in wireless ad hoc networks for the Internet of Things.

PubMed

Yang, Xin; Wang, Ling; Xie, Jian; Zhang, Zhaolin

2018-01-01

Wireless ad hoc networks can experience extreme fluctuations in transmission traffic in the Internet of Things, which is widely used today. Currently, the most crucial issues requiring attention for wireless ad hoc networks are making the best use of low traffic periods, reducing congestion during high traffic periods, and improving transmission performance. To solve these problems, the present paper proposes a novel cross-layer transmission model based on decentralized coded caching in the physical layer and a content division multiplexing scheme in the media access control layer. Simulation results demonstrate that the proposed model effectively addresses these issues by substantially increasing the throughput and successful transmission rate compared to existing protocols without a negative influence on delay, particularly for large scale networks under conditions of highly contrasting high and low traffic periods.

Cross-layer model design in wireless ad hoc networks for the Internet of Things

PubMed Central

Wang, Ling; Xie, Jian; Zhang, Zhaolin

2018-01-01

Wireless ad hoc networks can experience extreme fluctuations in transmission traffic in the Internet of Things, which is widely used today. Currently, the most crucial issues requiring attention for wireless ad hoc networks are making the best use of low traffic periods, reducing congestion during high traffic periods, and improving transmission performance. To solve these problems, the present paper proposes a novel cross-layer transmission model based on decentralized coded caching in the physical layer and a content division multiplexing scheme in the media access control layer. Simulation results demonstrate that the proposed model effectively addresses these issues by substantially increasing the throughput and successful transmission rate compared to existing protocols without a negative influence on delay, particularly for large scale networks under conditions of highly contrasting high and low traffic periods. PMID:29734355

A precise time synchronization method for 5G based on radio-over-fiber network with SDN controller

NASA Astrophysics Data System (ADS)

He, Linkuan; Wei, Baoguo; Yang, Hui; Yu, Ao; Wang, Zhengyong; Zhang, Jie

2018-02-01

There is an increasing demand on accurate time synchronization with the growing bandwidth of network service for 5G. In 5G network, it's necessary for base station to achieve accurate time synchronization to guarantee the quality of communication. In order to keep accuracy time for 5G network, we propose a time synchronization system for satellite ground station based on radio-over-fiber network (RoFN) with software defined optical network (SDON) controller. The advantage of this method is to improve the accuracy of time synchronization of ground station. The IEEE 1588 time synchronization protocol can solve the problems of high cost and lack of precision. However, in the process of time synchronization, distortion exists during the transmission of digital time signal. RoF uses analog optical transmission links and therefore analog transmission can be implemented among ground stations instead of digital transmission, which means distortion and bandwidth waste in the process of digital synchronization can be avoided. Additionally, the thought of SDN, software defined network, can optimize RoFN with centralized control and simplifying base station. Related simulation had been carried out to prove its superiority.

An evaluation plan of bus architectures and protocols using the NASA Ames intelligent redundant actuation system

NASA Technical Reports Server (NTRS)

Defeo, P.; Chen, M.

1987-01-01

Means for evaluating data bus architectures and protocols for highly integrated flight control system applications are needed. Described are the criteria and plans to do this by using the NASA/Ames Intelligent Redundant Actuation System (IRAS) experimental set-up. Candidate bus architectures differ from one another in terms of: topology, access control, message transfer schemes, message characteristics, initialization. data flow control, transmission rates, fault tolerance, and time synchronization. The evaluation criteria are developed relative to these features. A preliminary, analytical evaluation of four candidate busses (MIL-STD-1553B, DATAC, Ethernet, and HSIS) is described. A bus must be exercised in a real-time environment to evaluate its dynamic characteristics. A plan for real-time evaluation of these four busses using a combination of hardware and simulation techniques is presented.

Infection control and prevention practices implemented to reduce transmission risk of Middle East respiratory syndrome-coronavirus in a tertiary care institution in Saudi Arabia.

PubMed

Butt, Taimur S; Koutlakis-Barron, Irene; AlJumaah, Suliman; AlThawadi, Sahar; AlMofada, Saleh

2016-05-01

Transmission of Middle East respiratory syndrome-coronavirus (MERS-CoV) among health care workers (HCWs) and patients has been documented with mortality rate approximating 36%. We propose advanced infection control measures (A-IC) used in conjunction with basic infection control measures (B-IC) help reduce pathogen transmission. B-IC include standard and transmission-based precautions. A-IC are initiatives implemented within our center to enhance effectiveness of B-IC. Study effectiveness of combining B-IC and A-IC to prevent transmission of MERS-CoV to HCWs. A retrospective observational study was undertaken. A-IC measures include administrative support with daily rounds; infection control risk assessment; timely screening, isolation, and specimen analysis; collaboration; epidemic planning; stockpiling; implementation of contingency plans; full personal protective equipment use for advanced airway management; use of a real-time electronic isolation flagging system; infection prevention and control team on-call protocols; pretransfer MERS-CoV testing; and education. A total of 874 real-time polymerase chain reaction MERS-CoV tests were performed during the period beginning July 1, 2013, and ending January 31, 2015. Six hundred ninety-four non-HCWs were tested, of these 16 tested positive for MERS-CoV and their infection was community acquired. Sixty-nine percent of the confirmed MERS-CoV-positive cases were men, with an average age of 56 years (range, 19-84 years). Of the total tested for MERS-CoV, 180 individuals were HCWs with zero positivity. Adhering to a combination of B-IC and A-IC reduces the risk of MERS-CoV transmission to HCWs. Copyright © 2016 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

Quantitative evaluation of infection control models in the prevention of nosocomial transmission of SARS virus to healthcare workers: implication to nosocomial viral infection control for healthcare workers.

PubMed

Yen, Muh-Yong; Lu, Yun-Ching; Huang, Pi-Hsiang; Chen, Chen-Ming; Chen, Yee-Chun; Lin, Yusen E

2010-07-01

Healthcare workers (HCWs) are at high risk of acquiring emerging infections while caring for patients, as has been shown in the recent SARS and swine flu epidemics. Using SARS as an example, we determined the effectiveness of infection control measures (ICMs) by logistic regression and structural equation modelling (SEM), a quantitative methodology that can test a hypothetical model and validates causal relationships among ICMs. Logistic regression showed that installing hand wash stations in the emergency room (p = 0.012, odds ratio = 1.07) was the only ICM significantly associated with the protection of HCWs from acquiring the SARS virus. The structural equation modelling results showed that the most important contributing factor (highest proportion of effectiveness) was installation of a fever screening station outside the emergency department (51%). Other measures included traffic control in the emergency department (19%), availability of an outbreak standard operation protocol (12%), mandatory temperature screening (9%), establishing a hand washing setup at each hospital checkpoint (3%), adding simplified isolation rooms (3%), and a standardized patient transfer protocol (3%). Installation of fever screening stations outside of the hospital and implementing traffic control in the emergency department contributed to 70% of the effectiveness in the prevention of SARS transmission. Our approach can be applied to the evaluation of control measures for other epidemic infectious diseases, including swine flu and avian flu.

Parallel processing data network of master and slave transputers controlled by a serial control network

DOEpatents

Crosetto, D.B.

1996-12-31

The present device provides for a dynamically configurable communication network having a multi-processor parallel processing system having a serial communication network and a high speed parallel communication network. The serial communication network is used to disseminate commands from a master processor to a plurality of slave processors to effect communication protocol, to control transmission of high density data among nodes and to monitor each slave processor`s status. The high speed parallel processing network is used to effect the transmission of high density data among nodes in the parallel processing system. Each node comprises a transputer, a digital signal processor, a parallel transfer controller, and two three-port memory devices. A communication switch within each node connects it to a fast parallel hardware channel through which all high density data arrives or leaves the node. 6 figs.

Parallel processing data network of master and slave transputers controlled by a serial control network

DOEpatents

Crosetto, Dario B.

1996-01-01

The present device provides for a dynamically configurable communication network having a multi-processor parallel processing system having a serial communication network and a high speed parallel communication network. The serial communication network is used to disseminate commands from a master processor (100) to a plurality of slave processors (200) to effect communication protocol, to control transmission of high density data among nodes and to monitor each slave processor's status. The high speed parallel processing network is used to effect the transmission of high density data among nodes in the parallel processing system. Each node comprises a transputer (104), a digital signal processor (114), a parallel transfer controller (106), and two three-port memory devices. A communication switch (108) within each node (100) connects it to a fast parallel hardware channel (70) through which all high density data arrives or leaves the node.

Cluster-based adaptive power control protocol using Hidden Markov Model for Wireless Sensor Networks

NASA Astrophysics Data System (ADS)

Vinutha, C. B.; Nalini, N.; Nagaraja, M.

2017-06-01

This paper presents strategies for an efficient and dynamic transmission power control technique, in order to reduce packet drop and hence energy consumption of power-hungry sensor nodes operated in highly non-linear channel conditions of Wireless Sensor Networks. Besides, we also focus to prolong network lifetime and scalability by designing cluster-based network structure. Specifically we consider weight-based clustering approach wherein, minimum significant node is chosen as Cluster Head (CH) which is computed stemmed from the factors distance, remaining residual battery power and received signal strength (RSS). Further, transmission power control schemes to fit into dynamic channel conditions are meticulously implemented using Hidden Markov Model (HMM) where probability transition matrix is formulated based on the observed RSS measurements. Typically, CH estimates initial transmission power of its cluster members (CMs) from RSS using HMM and broadcast this value to its CMs for initialising their power value. Further, if CH finds that there are variations in link quality and RSS of the CMs, it again re-computes and optimises the transmission power level of the nodes using HMM to avoid packet loss due noise interference. We have demonstrated our simulation results to prove that our technique efficiently controls the power levels of sensing nodes to save significant quantity of energy for different sized network.

Effects of the Voice over Internet Protocol on Perturbation Analysis of Normal and Pathological Phonation

PubMed Central

Zhu, Yanmei; Witt, Rachel E.; MacCallum, Julia K.; Jiang, Jack J.

2010-01-01

Objective In this study, a Voice over Internet Protocol (VoIP) communication based on G.729 protocol was simulated to determine the effects of this system on acoustic perturbation parameters of normal and pathological voice signals. Patients and Methods: Fifty recordings of normal voice and 48 recordings of pathological voice affected by laryngeal paralysis were transmitted through a VoIP communication system. The acoustic analysis programs of CSpeech and MDVP were used to determine the percent jitter and percent shimmer from the voice samples before and after VoIP transmission. The effects of three frequently used audio compression protocols (MP3, WMA, and FLAC) on the perturbation measures were also studied. Results It was found that VoIP transmission disrupts the waveform and increases the percent jitter and percent shimmer of voice samples. However, after VoIP transmission, significant discrimination between normal and pathological voices affected by laryngeal paralysis was still possible. It was found that the lossless compression method FLAC does not exert any influence on the perturbation measures. The lossy compression methods MP3 and WMA increase percent jitter and percent shimmer values. Conclusion This study validates the feasibility of these transmission and compression protocols in developing remote voice signal data collection and assessment systems. PMID:20588051

Sagnac secret sharing over telecom fiber networks.

PubMed

Bogdanski, Jan; Ahrens, Johan; Bourennane, Mohamed

2009-01-19

We report the first Sagnac quantum secret sharing (in three-and four-party implementations) over 1550 nm single mode fiber (SMF) networks, using a single qubit protocol with phase encoding. Our secret sharing experiment has been based on a single qubit protocol, which has opened the door to practical secret sharing implementation over fiber telecom channels and in free-space. The previous quantum secret sharing proposals were based on multiparticle entangled states, difficult in the practical implementation and not scalable. Our experimental data in the three-party implementation show stable (in regards to birefringence drift) quantum secret sharing transmissions at the total Sagnac transmission loop distances of 55-75 km with the quantum bit error rates (QBER) of 2.3-2.4% for the mean photon number micro?= 0.1 and 1.7-2.1% for micro= 0.3. In the four-party case we have achieved quantum secret sharing transmissions at the total Sagnac transmission loop distances of 45-55 km with the quantum bit error rates (QBER) of 3.0-3.7% for the mean photon number micro= 0.1 and 1.8-3.0% for micro?= 0.3. The stability of quantum transmission has been achieved thanks to our new concept for compensation of SMF birefringence effects in Sagnac, based on a polarization control system and a polarization insensitive phase modulator. The measurement results have showed feasibility of quantum secret sharing over telecom fiber networks in Sagnac configuration, using standard fiber telecom components.

A Seamless Ubiquitous Telehealthcare Tunnel

PubMed Central

Cheng, Po-Hsun; Lin, Bor-Shing; Yu, Chu; Hu, Shun-Hsiang; Chen, Sao-Jie

2013-01-01

Mobile handheld devices are rapidly using to implement healthcare services around the World. Fundamentally, these services utilize telemedicine technologies. A disconnection of a mobile telemedicine system usually results in an interruption, which is embarrassing, and reconnection is necessary during the communication session. In this study, the Stream Control Transmission Protocol (SCTP) is adopted to build a stable session tunnel to guarantee seamless switching among heterogeneous wireless communication standards, such as Wi-Fi and 3G. This arrangement means that the telemedicine devices will not be limited by a fixed wireless connection and can switch to a better wireless channel if necessary. The tunnel can transmit plain text, binary data, and video streams. According to the evaluation of the proposed software-based SCTP-Tunnel middleware shown, the performance is lower than anticipated and is slightly slower than a fixed connection. However, the transmission throughput is still acceptable for healthcare professionals in a healthcare enterprise or home care site. It is necessary to build more heterogeneous wireless protocols into the proposed tunnel-switching scheme to support all possible communication protocols. In addition, SCTP is another good choice for promoting communication in telemedicine and healthcare fields. PMID:23917812

Non-Orthogonal Random Access in MIMO Cognitive Radio Networks: Beamforming, Power Allocation, and Opportunistic Transmission

PubMed Central

Lin, Huifa; Shin, Won-Yong

2017-01-01

We study secondary random access in multi-input multi-output cognitive radio networks, where a slotted ALOHA-type protocol and successive interference cancellation are used. We first introduce three types of transmit beamforming performed by secondary users, where multiple antennas are used to suppress the interference at the primary base station and/or to increase the received signal power at the secondary base station. Then, we show a simple decentralized power allocation along with the equivalent single-antenna conversion. To exploit the multiuser diversity gain, an opportunistic transmission protocol is proposed, where the secondary users generating less interference are opportunistically selected, resulting in a further reduction of the interference temperature. The proposed methods are validated via computer simulations. Numerical results show that increasing the number of transmit antennas can greatly reduce the interference temperature, while increasing the number of receive antennas leads to a reduction of the total transmit power. Optimal parameter values of the opportunistic transmission protocol are examined according to three types of beamforming and different antenna configurations, in terms of maximizing the cognitive transmission capacity. All the beamforming, decentralized power allocation, and opportunistic transmission protocol are performed by the secondary users in a decentralized manner, thus resulting in an easy implementation in practice. PMID:28076402

Non-Orthogonal Random Access in MIMO Cognitive Radio Networks: Beamforming, Power Allocation, and Opportunistic Transmission.

PubMed

Lin, Huifa; Shin, Won-Yong

2017-01-01

We study secondary random access in multi-input multi-output cognitive radio networks, where a slotted ALOHA-type protocol and successive interference cancellation are used. We first introduce three types of transmit beamforming performed by secondary users, where multiple antennas are used to suppress the interference at the primary base station and/or to increase the received signal power at the secondary base station. Then, we show a simple decentralized power allocation along with the equivalent single-antenna conversion. To exploit the multiuser diversity gain, an opportunistic transmission protocol is proposed, where the secondary users generating less interference are opportunistically selected, resulting in a further reduction of the interference temperature. The proposed methods are validated via computer simulations. Numerical results show that increasing the number of transmit antennas can greatly reduce the interference temperature, while increasing the number of receive antennas leads to a reduction of the total transmit power. Optimal parameter values of the opportunistic transmission protocol are examined according to three types of beamforming and different antenna configurations, in terms of maximizing the cognitive transmission capacity. All the beamforming, decentralized power allocation, and opportunistic transmission protocol are performed by the secondary users in a decentralized manner, thus resulting in an easy implementation in practice.

A concept to standardize raw biosignal transmission for brain-computer interfaces.

PubMed

Breitwieser, Christian; Neuper, Christa; Müller-Putz, Gernot R

2011-01-01

With this concept we introduced the attempt of a standardized interface called TiA to transmit raw biosignals. TiA is able to deal with multirate and block-oriented data transmission. Data is distinguished by different signal types (e.g., EEG, EOG, NIRS, …), whereby those signals can be acquired at the same time from different acquisition devices. TiA is built as a client-server model. Multiple clients can connect to one server. Information is exchanged via a control- and a separated data connection. Control commands and meta information are transmitted over the control connection. Raw biosignal data is delivered using the data connection in a unidirectional way. For this purpose a standardized handshaking protocol and raw data packet have been developed. Thus, an abstraction layer between hardware devices and data processing was evolved facilitating standardization.

Dynamic quality of service model for improving performance of multimedia real-time transmission in industrial networks.

PubMed

Gopalakrishnan, Ravichandran C; Karunakaran, Manivannan

2014-01-01

Nowadays, quality of service (QoS) is very popular in various research areas like distributed systems, multimedia real-time applications and networking. The requirements of these systems are to satisfy reliability, uptime, security constraints and throughput as well as application specific requirements. The real-time multimedia applications are commonly distributed over the network and meet various time constraints across networks without creating any intervention over control flows. In particular, video compressors make variable bit-rate streams that mismatch the constant-bit-rate channels typically provided by classical real-time protocols, severely reducing the efficiency of network utilization. Thus, it is necessary to enlarge the communication bandwidth to transfer the compressed multimedia streams using Flexible Time Triggered- Enhanced Switched Ethernet (FTT-ESE) protocol. FTT-ESE provides automation to calculate the compression level and change the bandwidth of the stream. This paper focuses on low-latency multimedia transmission over Ethernet with dynamic quality-of-service (QoS) management. This proposed framework deals with a dynamic QoS for multimedia transmission over Ethernet with FTT-ESE protocol. This paper also presents distinct QoS metrics based both on the image quality and network features. Some experiments with recorded and live video streams show the advantages of the proposed framework. To validate the solution we have designed and implemented a simulator based on the Matlab/Simulink, which is a tool to evaluate different network architecture using Simulink blocks.

The Integrated Safety-Critical Advanced Avionics Communication and Control (ISAACC) System Concept: Infrastructure for ISHM

NASA Technical Reports Server (NTRS)

Gwaltney, David A.; Briscoe, Jeri M.

2005-01-01

Integrated System Health Management (ISHM) architectures for spacecraft will include hard real-time, critical subsystems and soft real-time monitoring subsystems. Interaction between these subsystems will be necessary and an architecture supporting multiple criticality levels will be required. Demonstration hardware for the Integrated Safety-Critical Advanced Avionics Communication & Control (ISAACC) system has been developed at NASA Marshall Space Flight Center. It is a modular system using a commercially available time-triggered protocol, ?Tp/C, that supports hard real-time distributed control systems independent of the data transmission medium. The protocol is implemented in hardware and provides guaranteed low-latency messaging with inherent fault-tolerance and fault-containment. Interoperability between modules and systems of modules using the TTP/C is guaranteed through definition of messages and the precise message schedule implemented by the master-less Time Division Multiple Access (TDMA) communications protocol. "Plug-and-play" capability for sensors and actuators provides automatically configurable modules supporting sensor recalibration and control algorithm re-tuning without software modification. Modular components of controlled physical system(s) critical to control algorithm tuning, such as pumps or valve components in an engine, can be replaced or upgraded as "plug and play" components without modification to the ISAACC module hardware or software. ISAACC modules can communicate with other vehicle subsystems through time-triggered protocols or other communications protocols implemented over Ethernet, MIL-STD- 1553 and RS-485/422. Other communication bus physical layers and protocols can be included as required. In this way, the ISAACC modules can be part of a system-of-systems in a vehicle with multi-tier subsystems of varying criticality. The goal of the ISAACC architecture development is control and monitoring of safety critical systems of a manned spacecraft. These systems include spacecraft navigation and attitude control, propulsion, automated docking, vehicle health management and life support. ISAACC can integrate local critical subsystem health management with subsystems performing long term health monitoring. The ISAACC system and its relationship to ISHM will be presented.

A decentralized fuzzy C-means-based energy-efficient routing protocol for wireless sensor networks.

PubMed

Alia, Osama Moh'd

2014-01-01

Energy conservation in wireless sensor networks (WSNs) is a vital consideration when designing wireless networking protocols. In this paper, we propose a Decentralized Fuzzy Clustering Protocol, named DCFP, which minimizes total network energy dissipation to promote maximum network lifetime. The process of constructing the infrastructure for a given WSN is performed only once at the beginning of the protocol at a base station, which remains unchanged throughout the network's lifetime. In this initial construction step, a fuzzy C-means algorithm is adopted to allocate sensor nodes into their most appropriate clusters. Subsequently, the protocol runs its rounds where each round is divided into a CH-Election phase and a Data Transmission phase. In the CH-Election phase, the election of new cluster heads is done locally in each cluster where a new multicriteria objective function is proposed to enhance the quality of elected cluster heads. In the Data Transmission phase, the sensing and data transmission from each sensor node to their respective cluster head is performed and cluster heads in turn aggregate and send the sensed data to the base station. Simulation results demonstrate that the proposed protocol improves network lifetime, data delivery, and energy consumption compared to other well-known energy-efficient protocols.

A Decentralized Fuzzy C-Means-Based Energy-Efficient Routing Protocol for Wireless Sensor Networks

PubMed Central

2014-01-01

Energy conservation in wireless sensor networks (WSNs) is a vital consideration when designing wireless networking protocols. In this paper, we propose a Decentralized Fuzzy Clustering Protocol, named DCFP, which minimizes total network energy dissipation to promote maximum network lifetime. The process of constructing the infrastructure for a given WSN is performed only once at the beginning of the protocol at a base station, which remains unchanged throughout the network's lifetime. In this initial construction step, a fuzzy C-means algorithm is adopted to allocate sensor nodes into their most appropriate clusters. Subsequently, the protocol runs its rounds where each round is divided into a CH-Election phase and a Data Transmission phase. In the CH-Election phase, the election of new cluster heads is done locally in each cluster where a new multicriteria objective function is proposed to enhance the quality of elected cluster heads. In the Data Transmission phase, the sensing and data transmission from each sensor node to their respective cluster head is performed and cluster heads in turn aggregate and send the sensed data to the base station. Simulation results demonstrate that the proposed protocol improves network lifetime, data delivery, and energy consumption compared to other well-known energy-efficient protocols. PMID:25162060

Data Transfer Efficiency Over Satellite Circuits Using a Multi-Socket Extension to the File Transfer Protocol (FTP)

NASA Technical Reports Server (NTRS)

Allman, Mark; Ostermann, Shawn; Kruse, Hans

1996-01-01

In several experiments using NASA's Advanced Communications Technology Satellite (ACTS), investigators have reported disappointing throughput using the transmission control protocol/Internet protocol (TCP/IP) protocol suite over 1.536Mbit/sec (T1) satellite circuits. A detailed analysis of file transfer protocol (FTP) file transfers reveals that both the TCP window size and the TCP 'slow starter' algorithm contribute to the observed limits in throughput. In this paper we summarize the experimental and and theoretical analysis of the throughput limit imposed by TCP on the satellite circuit. We then discuss in detail the implementation of a multi-socket FTP, XFTP client and server. XFTP has been tested using the ACTS system. Finally, we discuss a preliminary set of tests on a link with non-zero bit error rates. XFTP shows promising performance under these conditions, suggesting the possibility that a multi-socket application may be less effected by bit errors than a single, large-window TCP connection.

An Enhanced Reservation-Based MAC Protocol for IEEE 802.15.4 Networks

PubMed Central

Afonso, José A.; Silva, Helder D.; Macedo, Pedro; Rocha, Luis A.

2011-01-01

The IEEE 802.15.4 Medium Access Control (MAC) protocol is an enabling standard for wireless sensor networks. In order to support applications requiring dedicated bandwidth or bounded delay, it provides a reservation-based scheme named Guaranteed Time Slot (GTS). However, the GTS scheme presents some drawbacks, such as inefficient bandwidth utilization and support to a maximum of only seven devices. This paper presents eLPRT (enhanced Low Power Real Time), a new reservation-based MAC protocol that introduces several performance enhancing features in comparison to the GTS scheme. This MAC protocol builds on top of LPRT (Low Power Real Time) and includes various mechanisms designed to increase data transmission reliability against channel errors, improve bandwidth utilization and increase the number of supported devices. A motion capture system based on inertial and magnetic sensors has been used to validate the protocol. The effectiveness of the performance enhancements introduced by each of the new features is demonstrated through the provision of both simulation and experimental results. PMID:22163826

Adaptive Video Streaming Using Bandwidth Estimation for 3.5G Mobile Network

NASA Astrophysics Data System (ADS)

Nam, Hyeong-Min; Park, Chun-Su; Jung, Seung-Won; Ko, Sung-Jea

Currently deployed mobile networks including High Speed Downlink Packet Access (HSDPA) offer only best-effort Quality of Service (QoS). In wireless best effort networks, the bandwidth variation is a critical problem, especially, for mobile devices with small buffers. This is because the bandwidth variation leads to packet losses caused by buffer overflow as well as picture freezing due to high transmission delay or buffer underflow. In this paper, in order to provide seamless video streaming over HSDPA, we propose an efficient real-time video streaming method that consists of the available bandwidth (AB) estimation for the HSDPA network and the transmission rate control to prevent buffer overflows/underflows. In the proposed method, the client estimates the AB and the estimated AB is fed back to the server through real-time transport control protocol (RTCP) packets. Then, the server adaptively adjusts the transmission rate according to the estimated AB and the buffer state obtained from the RTCP feedback information. Experimental results show that the proposed method achieves seamless video streaming over the HSDPA network providing higher video quality and lower transmission delay.

Interrupting seasonal transmission of Schistosoma haematobium and control of soil-transmitted helminthiasis in northern and central Côte d'Ivoire: a SCORE study protocol.

PubMed

Tian-Bi, Yves-Nathan T; Ouattara, Mamadou; Knopp, Stefanie; Coulibaly, Jean T; Hürlimann, Eveline; Webster, Bonnie; Allan, Fiona; Rollinson, David; Meïté, Aboulaye; Diakité, Nana R; Konan, Cyrille K; N'Goran, Eliézer K; Utzinger, Jürg

2018-01-29

To achieve a world free of schistosomiasis, the objective is to scale up control and elimination efforts in all endemic countries. Where interruption of transmission is considered feasible, countries are encouraged to implement a comprehensive intervention package, including preventive chemotherapy, information, education and communication (IEC), water, sanitation and hygiene (WASH), and snail control. In northern and central Côte d'Ivoire, transmission of Schistosoma haematobium is seasonal and elimination might be achieved. In a cluster-randomised trial, we will assess different treatment schemes to interrupt S. haematobium transmission and control soil-transmitted helminthiasis over a 3-year period. We will compare the impact of (i) arm A: annual mass drug administration (MDA) with praziquantel and albendazole before the peak schistosomiasis transmission season; (ii) arm B: annual MDA after the peak schistosomiasis transmission season; (iii) arm C: two yearly treatments before and after peak schistosomiasis transmission; and (iv) arm D: annual MDA before peak schistosomiasis transmission, coupled with chemical snail control using niclosamide. The prevalence and intensity of S. haematobium and soil-transmitted helminth infections will be assessed using urine filtration and Kato-Katz thick smears, respectively, in six administrative regions in northern and central parts of Côte d'Ivoire. Once a year, urine and stool samples will be collected and examined from 50 children aged 5-8 years, 100 children aged 9-12 years and 50 adults aged 20-55 years in each of 60 selected villages. Changes in S. haematobium and soil-transmitted helminth prevalence and intensity will be assessed between years and stratified by intervention arm. In the 15 villages randomly assigned to intervention arm D, intermediate host snails will be collected three times per year, before niclosamide is applied to the selected freshwater bodies. The snail abundance and infection rates over time will allow drawing inference on the force of transmission. This cluster-randomised intervention trial will elucidate whether in an area with seasonal transmission, the four different treatment schemes can interrupt S. haematobium transmission and control soil-transmitted helminthiasis. Lessons learned will help to guide schistosomiasis control and elimination programmes elsewhere in Africa. ISRCTN ISRCTN10926858 . Registered 21 December 2016. Retrospectively registered.

Probabilistic Analysis of Hierarchical Cluster Protocols for Wireless Sensor Networks

NASA Astrophysics Data System (ADS)

Kaj, Ingemar

Wireless sensor networks are designed to extract data from the deployment environment and combine sensing, data processing and wireless communication to provide useful information for the network users. Hundreds or thousands of small embedded units, which operate under low-energy supply and with limited access to central network control, rely on interconnecting protocols to coordinate data aggregation and transmission. Energy efficiency is crucial and it has been proposed that cluster based and distributed architectures such as LEACH are particularly suitable. We analyse the random cluster hierarchy in this protocol and provide a solution for low-energy and limited-loss optimization. Moreover, we extend these results to a multi-level version of LEACH, where clusters of nodes again self-organize to form clusters of clusters, and so on.

A Novel Cross-Layer Routing Protocol Based on Network Coding for Underwater Sensor Networks.

PubMed

Wang, Hao; Wang, Shilian; Bu, Renfei; Zhang, Eryang

2017-08-08

Underwater wireless sensor networks (UWSNs) have attracted increasing attention in recent years because of their numerous applications in ocean monitoring, resource discovery and tactical surveillance. However, the design of reliable and efficient transmission and routing protocols is a challenge due to the low acoustic propagation speed and complex channel environment in UWSNs. In this paper, we propose a novel cross-layer routing protocol based on network coding (NCRP) for UWSNs, which utilizes network coding and cross-layer design to greedily forward data packets to sink nodes efficiently. The proposed NCRP takes full advantages of multicast transmission and decode packets jointly with encoded packets received from multiple potential nodes in the entire network. The transmission power is optimized in our design to extend the life cycle of the network. Moreover, we design a real-time routing maintenance protocol to update the route when detecting inefficient relay nodes. Substantial simulations in underwater environment by Network Simulator 3 (NS-3) show that NCRP significantly improves the network performance in terms of energy consumption, end-to-end delay and packet delivery ratio compared with other routing protocols for UWSNs.

Upgrade to the control system of the reflectometry diagnostic of ASDEX upgrade

NASA Astrophysics Data System (ADS)

Graça, S.; Santos, J.; Manso, M. E.

2004-10-01

The broadband frequency modulation-continuous wave microwave/millimeter wave reflectometer of ASDEX upgrade tokamak (Institut für Plasma Physik (IPP), Garching, Germany) developed by Centro de Fusão Nuclear (Lisboa, Portugal) with the collaboration of IPP, is a complex system with 13 channels (O and X modes) and two types of operation modes (swept and fixed frequency). The control system that ensures remote operation of the diagnostic incorporates VME and CAMAC bus based acquisition/timing systems. Microprocessor input/output boards are used to control and monitor the microwave circuitry and associated electronic devices. The implementation of the control system is based on an object-oriented client/server model: a centralized server manages the hardware and receives input from remote clients. Communication is handled through transmission control protocol/internet protocol sockets. Here we describe recent upgrades of the control system aiming to: (i) accommodate new channels; (ii) adapt to the heterogeneity of computing platforms and operating systems; and (iii) overcome remote access restrictions. Platform and operating system independence was achieved by redesigning the graphical user interface in JAVA. As secure shell is the standard remote access protocol adopted in major fusion laboratories, secure shell tunneling was implemented to allow remote operation of the diagnostic through the existing firewalls.

Secure ICCP Final Report

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

Rice, Mark J.; Bonebrake, Christopher A.; Dayley, Greg K.

Inter-Control Center Communications Protocol (ICCP), defined by the IEC 60870-6 TASE.2 standard, was developed to enable data exchange over wide area networks between electric system entities, including utility control centers, Independent System Operators (ISOs), Regional Transmission Operators (RTOs) and Independent Power Producers (IPP) also known as Non-Utility Generators (NUG). ICCP is an unprotected protocol, and as a result is vulnerable to such actions as integrity violation, interception or alteration, spoofing, and eavesdropping. Because of these vulnerabilities with unprotected ICCP communication, security enhancements, referred to as Secure ICCP, have been added and are included in the ICCP products that utilities havemore » received since 2003 when the standard was defined. This has resulted in an ICCP product whose communication can be encrypted and authenticated to address these vulnerabilities.« less

Contagious equine metritis: artificial reproduction changes the epidemiologic paradigm.

PubMed

Schulman, Martin Lance; May, Catherine Edith; Keys, Bronwyn; Guthrie, Alan John

2013-11-29

Recent CEM outbreak reports reflect a novel epidemiologic manifestation with a markedly different risk association for transmission via artificial reproduction and subsequent to inadvertent importation of unapparent carrier stallions. Artificial breeding has an increased association with horizontal or fomite-associated transmission. Reported risk factors include inadequate biosecurity protocols at centralised breeding facilities associated with stallion management and methods of semen collection, processing and transport. Detection of carriers is based on traditional bacteriology from genital swabs and despite limitations inherent to Taylorella equigenitalis is currently the gold standard applied in all international trade and movement protocols. These limitations are reported to be overcome by PCR assays improving diagnostic sensitivity and specificity, practicality, turn-around times, through-put and cost efficacy. Molecular methods have increased understanding of the Taylorelleae, facilitate epidemiologic surveillance and outbreak control strategies. Validation and international regulatory acceptance of a robust PCR-based assay and the undefined risks in association with cryopreserved semen and embryos are future areas warranting further investigation. Copyright © 2013 Elsevier B.V. All rights reserved.

Phase space dynamics and control of the quantum particles associated to hypergraph states

NASA Astrophysics Data System (ADS)

Berec, Vesna

2015-05-01

As today's nanotechnology focus becomes primarily oriented toward production and manipulation of materials at the subatomic level, allowing the performance and complexity of interconnects where the device density accepts more than hundreds devices on a single chip, the manipulation of semiconductor nanostructures at the subatomic level sets its prime tasks on preserving and adequate transmission of information encoded in specified (quantum) states. The presented study employs the quantum communication protocol based on the hypergraph network model where the numerical solutions of equations of motion of quantum particles are associated to vertices (assembled with device chip), which follow specific controllable paths in the phase space. We address these findings towards ultimate quest for prediction and selective control of quantum particle trajectories. In addition, presented protocols could represent valuable tool for reducing background noise and uncertainty in low-dimensional and operationally meaningful, scalable complex systems.

Design and implementation of new control room system in Damavand tokamak

NASA Astrophysics Data System (ADS)

Rasouli, H.; Zamanian, H.; Gheidi, M.; Kheiri-Fard, M.; Kouhi, A.

2017-07-01

The aim of this paper is design and implementation of an up-to-date control room. The previous control room had a lot of constraints and it was not apposite to the sophisticated diagnostic systems as well as to the modern control and multivariable systems. Although it provided the best output for the considered experiments and implementing offline algorithms among all similar plants, it needed to be developed to provide more capability for complex algorithm mechanisms and this work introduces our efforts in this area. Accordingly, four leading systems were designed and implemented, including real-time control system, online Data Acquisition System (DAS), offline DAS, monitoring and data transmission system. In the control system, three real-time control modules were established based on Digital Signal Processor (DSP). Thanks to them, implementation of the classic and linear and nonlinear intelligent controllers was possible to control the plasma position and its elongation. Also, online DAS was constructed in two modules. Using them, voltages and currents of charge for the capacitor banks and pressure of different parts in vacuum vessel were measured and monitored. Likewise, by real-time processing of the online data, the safety protocol of plant performance was accomplished. In addition, the offline DAS was organized in 13 modules based on Field Programmable Gate Array (FPGA). This system can be used for gathering all diagnostic, control, and performance data in 156 channels. Data transmission system and storing mechanism in the server was provided by data transmitting network and MDSplus standard protocol. Moreover, monitoring software was designed so that it could display the required plots for physical analyses. Taking everything into account, this new platform can improve the quality and quantity of research activities in plasma physics for Damavand tokamak.

Leo Satellite Communication through a LEO Constellation using TCP/IP Over ATM

NASA Technical Reports Server (NTRS)

Foore, Lawrence R.; Konangi, Vijay K.; Wallett, Thomas M.

1999-01-01

The simulated performance characteristics for communication between a terrestrial client and a Low Earth Orbit (LEO) satellite server are presented. The client and server nodes consist of a Transmission Control Protocol /Internet Protocol (TCP/IP) over ATM configuration. The ATM cells from the client or the server are transmitted to a gateway, packaged with some header information and transferred to a commercial LEO satellite constellation. These cells are then routed through the constellation to a gateway on the globe that allows the client/server communication to take place. Unspecified Bit Rate (UBR) is specified as the quality of service (QoS). Various data rates are considered.

Performance Analysis of the IEEE 802.11p Multichannel MAC Protocol in Vehicular Ad Hoc Networks

PubMed Central

2017-01-01

Vehicular Ad Hoc Networks (VANETs) employ multichannel to provide a variety of safety and non-safety applications, based on the IEEE 802.11p and IEEE 1609.4 protocols. The safety applications require timely and reliable transmissions, while the non-safety applications require efficient and high throughput. In the IEEE 1609.4 protocol, operating interval is divided into alternating Control Channel (CCH) interval and Service Channel (SCH) interval with an identical length. During the CCH interval, nodes transmit safety-related messages and control messages, and Enhanced Distributed Channel Access (EDCA) mechanism is employed to allow four Access Categories (ACs) within a station with different priorities according to their criticality for the vehicle’s safety. During the SCH interval, the non-safety massages are transmitted. An analytical model is proposed in this paper to evaluate performance, reliability and efficiency of the IEEE 802.11p and IEEE 1609.4 protocols. The proposed model improves the existing work by taking serval aspects and the character of multichannel switching into design consideration. Extensive performance evaluations based on analysis and simulation help to validate the accuracy of the proposed model and analyze the capabilities and limitations of the IEEE 802.11p and IEEE 1609.4 protocols, and enhancement suggestions are given. PMID:29231882

Performance Analysis of the IEEE 802.11p Multichannel MAC Protocol in Vehicular Ad Hoc Networks.

PubMed

Song, Caixia

2017-12-12

Vehicular Ad Hoc Networks (VANETs) employ multichannel to provide a variety of safety and non-safety applications, based on the IEEE 802.11p and IEEE 1609.4 protocols. The safety applications require timely and reliable transmissions, while the non-safety applications require efficient and high throughput. In the IEEE 1609.4 protocol, operating interval is divided into alternating Control Channel (CCH) interval and Service Channel (SCH) interval with an identical length. During the CCH interval, nodes transmit safety-related messages and control messages, and Enhanced Distributed Channel Access (EDCA) mechanism is employed to allow four Access Categories (ACs) within a station with different priorities according to their criticality for the vehicle's safety. During the SCH interval, the non-safety massages are transmitted. An analytical model is proposed in this paper to evaluate performance, reliability and efficiency of the IEEE 802.11p and IEEE 1609.4 protocols. The proposed model improves the existing work by taking serval aspects and the character of multichannel switching into design consideration. Extensive performance evaluations based on analysis and simulation help to validate the accuracy of the proposed model and analyze the capabilities and limitations of the IEEE 802.11p and IEEE 1609.4 protocols, and enhancement suggestions are given.

TCP Pacing Developed

NASA Technical Reports Server (NTRS)

Ivancic, William D.

2002-01-01

Transmission control protocol (TCP) was conceived and designed to run over a variety of communication links, including wireless and high-bandwidth links. However, with recent technological advances in satellite and fiber-optic networks, researchers are reevaluating the flexibility of TCP. The TCP pacing and packet pair probing implementation may help overcome two of the major obstacles identified for efficient bandwidth utilization over communication links with large delay-bandwidth products.

Communications protocol

NASA Technical Reports Server (NTRS)

Zhou, Xiaoming (Inventor); Baras, John S. (Inventor)

2010-01-01

The present invention relates to an improved communications protocol which increases the efficiency of transmission in return channels on a multi-channel slotted Alohas system by incorporating advanced error correction algorithms, selective retransmission protocols and the use of reserved channels to satisfy the retransmission requests.

Heralded quantum controlled-phase gates with dissipative dynamics in macroscopically distant resonators

NASA Astrophysics Data System (ADS)

Qin, Wei; Wang, Xin; Miranowicz, Adam; Zhong, Zhirong; Nori, Franco

2017-07-01

Heralded near-deterministic multiqubit controlled-phase gates with integrated error detection have recently been proposed by Borregaard et al. [Phys. Rev. Lett. 114, 110502 (2015), 10.1103/PhysRevLett.114.110502]. This protocol is based on a single four-level atom (a heralding quartit) and N three-level atoms (operational qutrits) coupled to a single-resonator mode acting as a cavity bus. Here we generalize this method for two distant resonators without the cavity bus between the heralding and operational atoms. Specifically, we analyze the two-qubit controlled-Z gate and its multiqubit-controlled generalization (i.e., a Toffoli-like gate) acting on the two-lowest levels of N qutrits inside one resonator, with their successful actions being heralded by an auxiliary microwave-driven quartit inside the other resonator. Moreover, we propose a circuit-quantum-electrodynamics realization of the protocol with flux and phase qudits in linearly coupled transmission-line resonators with dissipation. These methods offer a quadratic fidelity improvement compared to cavity-assisted deterministic gates.

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.

Data transmission protocol for Pi-of-the-Sky cameras

NASA Astrophysics Data System (ADS)

Uzycki, J.; Kasprowicz, G.; Mankiewicz, M.; Nawrocki, K.; Sitek, P.; Sokolowski, M.; Sulej, R.; Tlaczala, W.

2006-10-01

The large amount of data collected by the automatic astronomical cameras has to be transferred to the fast computers in a reliable way. The method chosen should ensure data streaming in both directions but in nonsymmetrical way. The Ethernet interface is very good choice because of its popularity and proven performance. However it requires TCP/IP stack implementation in devices like cameras for full compliance with existing network and operating systems. This paper describes NUDP protocol, which was made as supplement to standard UDP protocol and can be used as a simple-network protocol. The NUDP does not need TCP protocol implementation and makes it possible to run the Ethernet network with simple devices based on microcontroller and/or FPGA chips. The data transmission idea was created especially for the "Pi of the Sky" project.

An Energy-Efficient and High-Quality Video Transmission Architecture in Wireless Video-Based Sensor Networks.

PubMed

Aghdasi, Hadi S; Abbaspour, Maghsoud; Moghadam, Mohsen Ebrahimi; Samei, Yasaman

2008-08-04

Technological progress in the fields of Micro Electro-Mechanical Systems (MEMS) and wireless communications and also the availability of CMOS cameras, microphones and small-scale array sensors, which may ubiquitously capture multimedia content from the field, have fostered the development of low-cost limited resources Wireless Video-based Sensor Networks (WVSN). With regards to the constraints of videobased sensor nodes and wireless sensor networks, a supporting video stream is not easy to implement with the present sensor network protocols. In this paper, a thorough architecture is presented for video transmission over WVSN called Energy-efficient and high-Quality Video transmission Architecture (EQV-Architecture). This architecture influences three layers of communication protocol stack and considers wireless video sensor nodes constraints like limited process and energy resources while video quality is preserved in the receiver side. Application, transport, and network layers are the layers in which the compression protocol, transport protocol, and routing protocol are proposed respectively, also a dropping scheme is presented in network layer. Simulation results over various environments with dissimilar conditions revealed the effectiveness of the architecture in improving the lifetime of the network as well as preserving the video quality.

A Novel Cross-Layer Routing Protocol Based on Network Coding for Underwater Sensor Networks

PubMed Central

Wang, Hao; Wang, Shilian; Bu, Renfei; Zhang, Eryang

2017-01-01

Underwater wireless sensor networks (UWSNs) have attracted increasing attention in recent years because of their numerous applications in ocean monitoring, resource discovery and tactical surveillance. However, the design of reliable and efficient transmission and routing protocols is a challenge due to the low acoustic propagation speed and complex channel environment in UWSNs. In this paper, we propose a novel cross-layer routing protocol based on network coding (NCRP) for UWSNs, which utilizes network coding and cross-layer design to greedily forward data packets to sink nodes efficiently. The proposed NCRP takes full advantages of multicast transmission and decode packets jointly with encoded packets received from multiple potential nodes in the entire network. The transmission power is optimized in our design to extend the life cycle of the network. Moreover, we design a real-time routing maintenance protocol to update the route when detecting inefficient relay nodes. Substantial simulations in underwater environment by Network Simulator 3 (NS-3) show that NCRP significantly improves the network performance in terms of energy consumption, end-to-end delay and packet delivery ratio compared with other routing protocols for UWSNs. PMID:28786915

A Hybrid Lifetime Extended Directional Approach for WBANs

PubMed Central

Li, Changle; Yuan, Xiaoming; Yang, Li; Song, Yueyang

2015-01-01

Wireless Body Area Networks (WBANs) can provide real-time and reliable health monitoring, attributing to the human-centered and sensor interoperability properties. WBANs have become a key component of the ubiquitous eHealth (electronic health) revolution that prospers on the basis of information and communication technologies. The prime consideration in WBAN is how to maximize the network lifetime with battery-powered sensor nodes in energy constraint. Novel solutions in Medium Access Control (MAC) protocols are imperative to satisfy the particular BAN scenario and the need of excellent energy efficiency in healthcare applications. In this paper, we propose a hybrid Lifetime Extended Directional Approach (LEDA) MAC protocol based on IEEE 802.15.6 to reduce energy consumption and prolong network lifetime. The LEDA MAC protocol takes full advantages of directional superiority in energy saving that employs multi-beam directional mode in Carrier Sense Multiple Access/Collision Avoidance (CSMA/CA) and single-beam directional mode in Time Division Multiple Access (TDMA) for alternative in data reservation and transmission according to the traffic varieties. Moreover, the impacts of some inherent problems of directional antennas such as deafness and hidden terminal problem can be decreased owing to that all nodes generate individual beam according to user priorities designated. Furthermore, LEDA MAC employs a Dynamic Polled Allocation Period (DPAP) for burst data transmissions to increase the network reliability and adaptability. Extensive analysis and simulation results show that the proposed LEDA MAC protocol achieves extended network lifetime with improved performance compared with IEEE 802.15.6. PMID:26556357

Infinite horizon optimal impulsive control with applications to Internet congestion control

NASA Astrophysics Data System (ADS)

Avrachenkov, Konstantin; Habachi, Oussama; Piunovskiy, Alexey; Zhang, Yi

2015-04-01

We investigate infinite-horizon deterministic optimal control problems with both gradual and impulsive controls, where any finitely many impulses are allowed simultaneously. Both discounted and long-run time-average criteria are considered. We establish very general and at the same time natural conditions, under which the dynamic programming approach results in an optimal feedback policy. The established theoretical results are applied to the Internet congestion control, and by solving analytically and nontrivially the underlying optimal control problems, we obtain a simple threshold-based active queue management scheme, which takes into account the main parameters of the transmission control protocols, and improves the fairness among the connections in a given network.

Can SNMP be Used to Create a Silent SS in an 802.16 Implementation

DTIC Science & Technology

2008-09-01

wireless transmissions by using the Simple Network Management Protocol (SNMP). SNMP is a networking protocol that can be used by network ...802.16 as a unique networking technology. In a more familiar wireless networking environment like Wi-Fi, there is no central scheduler for access to...much a concern due to the scheduling algorithm , this power saving method provides good transmission security as a

Enhanced protocol for real-time transmission of echocardiograms over wireless channels.

PubMed

Cavero, Eva; Alesanco, Alvaro; García, Jose

2012-11-01

This paper presents a methodology to transmit clinical video over wireless networks in real-time. A 3-D set partitioning in hierarchical trees compression prior to transmission is proposed. In order to guarantee the clinical quality of the compressed video, a clinical evaluation specific to each video modality has to be made. This evaluation indicates the minimal transmission rate necessary for an accurate diagnosis. However, the channel conditions produce errors and distort the video. A reliable application protocol is therefore proposed using a hybrid solution in which either retransmission or retransmission combined with forward error correction (FEC) techniques are used, depending on the channel conditions. In order to analyze the proposed methodology, the 2-D mode of an echocardiogram has been assessed. A bandwidth of 200 kbps is necessary to guarantee its clinical quality. The transmission using the proposed solution and retransmission and FEC techniques working separately have been simulated and compared in high-speed uplink packet access (HSUPA) and worldwide interoperability for microwave access (WiMAX) networks. The proposed protocol achieves guaranteed clinical quality for bit error rates higher than with the other protocols, being for a mobile speed of 60 km/h up to 3.3 times higher for HSUPA and 10 times for WiMAX.

IJS: An Intelligent Junction Selection Based Routing Protocol for VANET to Support ITS Services.

PubMed

Bhoi, Sourav Kumar; Khilar, Pabitra Mohan

2014-01-01

Selecting junctions intelligently for data transmission provides better intelligent transportation system (ITS) services. The main problem in vehicular communication is high disturbances of link connectivity due to mobility and less density of vehicles. If link conditions are predicted earlier, then there is a less chance of performance degradation. In this paper, an intelligent junction selection based routing protocol (IJS) is proposed to transmit the data in a quickest path, in which the vehicles are mostly connected and have less link connectivity problem. In this protocol, a helping vehicle is set at every junction to control the communication by predicting link failures or network gaps in a route. Helping vehicle at the junction produces a score for every neighboring junction to forward the data to the destination by considering the current traffic information and selects that junction which has minimum score. IJS protocol is implemented and compared with GyTAR, A-STAR, and GSR routing protocols. Simulation results show that IJS performs better in terms of average end-to-end delay, network gap encounter, and number of hops.

IJS: An Intelligent Junction Selection Based Routing Protocol for VANET to Support ITS Services

PubMed Central

Khilar, Pabitra Mohan

2014-01-01

Selecting junctions intelligently for data transmission provides better intelligent transportation system (ITS) services. The main problem in vehicular communication is high disturbances of link connectivity due to mobility and less density of vehicles. If link conditions are predicted earlier, then there is a less chance of performance degradation. In this paper, an intelligent junction selection based routing protocol (IJS) is proposed to transmit the data in a quickest path, in which the vehicles are mostly connected and have less link connectivity problem. In this protocol, a helping vehicle is set at every junction to control the communication by predicting link failures or network gaps in a route. Helping vehicle at the junction produces a score for every neighboring junction to forward the data to the destination by considering the current traffic information and selects that junction which has minimum score. IJS protocol is implemented and compared with GyTAR, A-STAR, and GSR routing protocols. Simulation results show that IJS performs better in terms of average end-to-end delay, network gap encounter, and number of hops. PMID:27433485

47 CFR 54.5 - Terms and definitions.

Code of Federal Regulations, 2013 CFR

2013-10-01

..., or making available information via telecommunications, and includes electronic publishing, but does... transmission of information as common carriage; (2) The transmission of information as part of a gateway to an... information, but may include data transmission, address translation, protocol conversion, billing management...

47 CFR 54.5 - Terms and definitions.

Code of Federal Regulations, 2014 CFR

2014-10-01

..., or making available information via telecommunications, and includes electronic publishing, but does... transmission of information as common carriage; and (2) The transmission of information as part of a gateway to... content of information, but may include data transmission, address translation, protocol conversion...

47 CFR 54.5 - Terms and definitions.

Code of Federal Regulations, 2012 CFR

2012-10-01

..., or making available information via telecommunications, and includes electronic publishing, but does... transmission of information as common carriage; (2) The transmission of information as part of a gateway to an... information, but may include data transmission, address translation, protocol conversion, billing management...

An Evaluation of Potential Operating Systems for Autonomous Underwater Vehicles

DTIC Science & Technology

2013-02-01

Remotely Operated Vehicle RTOS Real-Time Operating System SAUC -E Student Autonomous Underwater Vehicle Challenge - Europe TCP Transmission Control Protocol...popularity, with examples including the Student Autonomous Underwater Vehicle Challenge - Europe ( SAUC -E) [7] and the AUVSI robosub competition [8]. For...28] for entry into AUV competitions such as SAUC -E [7], and AUVSI [8]. 8 UNCLASSIFIED UNCLASSIFIED DSTO–TN–1194 3.4 Windows CE Windows CE

Ada (Trademark) Case Studies II.

DTIC Science & Technology

1984-01-01

number ( CSN ) in that character set’s "transmission identifier". The array is named START CSN , but a better name would be STARTOFCSN. The word of...protocols), CSN (Channel Sequence Number), EON (End of Message), LMF (Line Media Format), MCB (Message Control Block), RI (Routing Indicator), and TI...component names should end with -PART, - FIELD , or COMPONENT.El - Package names should end with PACKAGE. - Enumeration literals should have suffixes

Versatile synchronized real-time MEG hardware controller for large-scale fast data acquisition.

PubMed

Sun, Limin; Han, Menglai; Pratt, Kevin; Paulson, Douglas; Dinh, Christoph; Esch, Lorenz; Okada, Yoshio; Hämäläinen, Matti

2017-05-01

Versatile controllers for accurate, fast, and real-time synchronized acquisition of large-scale data are useful in many areas of science, engineering, and technology. Here, we describe the development of a controller software based on a technique called queued state machine for controlling the data acquisition (DAQ) hardware, continuously acquiring a large amount of data synchronized across a large number of channels (>400) at a fast rate (up to 20 kHz/channel) in real time, and interfacing with applications for real-time data analysis and display of electrophysiological data. This DAQ controller was developed specifically for a 384-channel pediatric whole-head magnetoencephalography (MEG) system, but its architecture is useful for wide applications. This controller running in a LabVIEW environment interfaces with microprocessors in the MEG sensor electronics to control their real-time operation. It also interfaces with a real-time MEG analysis software via transmission control protocol/internet protocol, to control the synchronous acquisition and transfer of the data in real time from >400 channels to acquisition and analysis workstations. The successful implementation of this controller for an MEG system with a large number of channels demonstrates the feasibility of employing the present architecture in several other applications.

Versatile synchronized real-time MEG hardware controller for large-scale fast data acquisition

NASA Astrophysics Data System (ADS)

Sun, Limin; Han, Menglai; Pratt, Kevin; Paulson, Douglas; Dinh, Christoph; Esch, Lorenz; Okada, Yoshio; Hämäläinen, Matti

2017-05-01

Versatile controllers for accurate, fast, and real-time synchronized acquisition of large-scale data are useful in many areas of science, engineering, and technology. Here, we describe the development of a controller software based on a technique called queued state machine for controlling the data acquisition (DAQ) hardware, continuously acquiring a large amount of data synchronized across a large number of channels (>400) at a fast rate (up to 20 kHz/channel) in real time, and interfacing with applications for real-time data analysis and display of electrophysiological data. This DAQ controller was developed specifically for a 384-channel pediatric whole-head magnetoencephalography (MEG) system, but its architecture is useful for wide applications. This controller running in a LabVIEW environment interfaces with microprocessors in the MEG sensor electronics to control their real-time operation. It also interfaces with a real-time MEG analysis software via transmission control protocol/internet protocol, to control the synchronous acquisition and transfer of the data in real time from >400 channels to acquisition and analysis workstations. The successful implementation of this controller for an MEG system with a large number of channels demonstrates the feasibility of employing the present architecture in several other applications.

Applications of Multi-Channel Safety Authentication Protocols in Wireless Networks.

PubMed

Chen, Young-Long; Liau, Ren-Hau; Chang, Liang-Yu

2016-01-01

People can use their web browser or mobile devices to access web services and applications which are built into these servers. Users have to input their identity and password to login the server. The identity and password may be appropriated by hackers when the network environment is not safe. The multiple secure authentication protocol can improve the security of the network environment. Mobile devices can be used to pass the authentication messages through Wi-Fi or 3G networks to serve as a second communication channel. The content of the message number is not considered in a multiple secure authentication protocol. The more excessive transmission of messages would be easier to collect and decode by hackers. In this paper, we propose two schemes which allow the server to validate the user and reduce the number of messages using the XOR operation. Our schemes can improve the security of the authentication protocol. The experimental results show that our proposed authentication protocols are more secure and effective. In regard to applications of second authentication communication channels for a smart access control system, identity identification and E-wallet, our proposed authentication protocols can ensure the safety of person and property, and achieve more effective security management mechanisms.

From Wagons to Race Cars, At Least Now We Have A Chassis

NASA Astrophysics Data System (ADS)

Morrow, A. L.

2003-12-01

For the past 30 years Very-Long-Baseline Interferometry (VLBI) has provided astronomers with the most accurate measurements to date of both distant radio sources as well as the tectonic plates. The resolutions attainable through VLBI are orders of magnitude better than other instruments. In order to transmit radio signals collected at different sites to a correlator for processing the VLBI data was stored on magnetic tapes, and then the magnetic tapes were shipped through the mail to the central processing site. This was not only arduous and inefficient, it was also costly. Now this means of shipment can be replaced by global high speed networks. This means of transmission is called e-VLBI. New protocols must be developed so e-VLBI can become a proficient high bandwidth background user. The protocol agreed upon uses a Real-time Transport Protocol (RTP) framework to preserve timing information and synchronization. The RTP is then transported using the Internet User Datagram Protocol (UDP) with RTP Control Protocol (RTCP) monitoring the networks performance. When this protocol is fully functional astronomers will be able to observe all over the world and receive results in real time.

Distributed and Modular CAN-Based Architecture for Hardware Control and Sensor Data Integration

PubMed Central

Losada, Diego P.; Fernández, Joaquín L.; Paz, Enrique; Sanz, Rafael

2017-01-01

In this article, we present a CAN-based (Controller Area Network) distributed system to integrate sensors, actuators and hardware controllers in a mobile robot platform. With this work, we provide a robust, simple, flexible and open system to make hardware elements or subsystems communicate, that can be applied to different robots or mobile platforms. Hardware modules can be connected to or disconnected from the CAN bus while the system is working. It has been tested in our mobile robot Rato, based on a RWI (Real World Interface) mobile platform, to replace the old sensor and motor controllers. It has also been used in the design of two new robots: BellBot and WatchBot. Currently, our hardware integration architecture supports different sensors, actuators and control subsystems, such as motor controllers and inertial measurement units. The integration architecture was tested and compared with other solutions through a performance analysis of relevant parameters such as transmission efficiency and bandwidth usage. The results conclude that the proposed solution implements a lightweight communication protocol for mobile robot applications that avoids transmission delays and overhead. PMID:28467381

Distributed and Modular CAN-Based Architecture for Hardware Control and Sensor Data Integration.

PubMed

Losada, Diego P; Fernández, Joaquín L; Paz, Enrique; Sanz, Rafael

2017-05-03

In this article, we present a CAN-based (Controller Area Network) distributed system to integrate sensors, actuators and hardware controllers in a mobile robot platform. With this work, we provide a robust, simple, flexible and open system to make hardware elements or subsystems communicate, that can be applied to different robots or mobile platforms. Hardware modules can be connected to or disconnected from the CAN bus while the system is working. It has been tested in our mobile robot Rato, based on a RWI (Real World Interface) mobile platform, to replace the old sensor and motor controllers. It has also been used in the design of two new robots: BellBot and WatchBot. Currently, our hardware integration architecture supports different sensors, actuators and control subsystems, such as motor controllers and inertial measurement units. The integration architecture was tested and compared with other solutions through a performance analysis of relevant parameters such as transmission efficiency and bandwidth usage. The results conclude that the proposed solution implements a lightweight communication protocol for mobile robot applications that avoids transmission delays and overhead.

Secure anonymous mutual authentication for star two-tier wireless body area networks.

PubMed

Ibrahim, Maged Hamada; Kumari, Saru; Das, Ashok Kumar; Wazid, Mohammad; Odelu, Vanga

2016-10-01

Mutual authentication is a very important service that must be established between sensor nodes in wireless body area network (WBAN) to ensure the originality and integrity of the patient's data sent by sensors distributed on different parts of the body. However, mutual authentication service is not enough. An adversary can benefit from monitoring the traffic and knowing which sensor is in transmission of patient's data. Observing the traffic (even without disclosing the context) and knowing its origin, it can reveal to the adversary information about the patient's medical conditions. Therefore, anonymity of the communicating sensors is an important service as well. Few works have been conducted in the area of mutual authentication among sensor nodes in WBAN. However, none of them has considered anonymity among body sensor nodes. Up to our knowledge, our protocol is the first attempt to consider this service in a two-tier WBAN. We propose a new secure protocol to realize anonymous mutual authentication and confidential transmission for star two-tier WBAN topology. The proposed protocol uses simple cryptographic primitives. We prove the security of the proposed protocol using the widely-accepted Burrows-Abadi-Needham (BAN) logic, and also through rigorous informal security analysis. In addition, to demonstrate the practicality of our protocol, we evaluate it using NS-2 simulator. BAN logic and informal security analysis prove that our proposed protocol achieves the necessary security requirements and goals of an authentication service. The simulation results show the impact on the various network parameters, such as end-to-end delay and throughput. The nodes in the network require to store few hundred bits. Nodes require to perform very few hash invocations, which are computationally very efficient. The communication cost of the proposed protocol is few hundred bits in one round of communication. Due to the low computation cost, the energy consumed by the nodes is also low. Our proposed protocol is a lightweight anonymous mutually authentication protocol to mutually authenticate the sensor nodes with the controller node (hub) in a star two-tier WBAN topology. Results show that our protocol proves efficiency over previously proposed protocols and at the same time, achieves the necessary security requirements for a secure anonymous mutual authentication scheme. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Comparative Study on Various Authentication Protocols in Wireless Sensor Networks.

PubMed

Rajeswari, S Raja; Seenivasagam, V

2016-01-01

Wireless sensor networks (WSNs) consist of lightweight devices with low cost, low power, and short-ranged wireless communication. The sensors can communicate with each other to form a network. In WSNs, broadcast transmission is widely used along with the maximum usage of wireless networks and their applications. Hence, it has become crucial to authenticate broadcast messages. Key management is also an active research topic in WSNs. Several key management schemes have been introduced, and their benefits are not recognized in a specific WSN application. Security services are vital for ensuring the integrity, authenticity, and confidentiality of the critical information. Therefore, the authentication mechanisms are required to support these security services and to be resilient to distinct attacks. Various authentication protocols such as key management protocols, lightweight authentication protocols, and broadcast authentication protocols are compared and analyzed for all secure transmission applications. The major goal of this survey is to compare and find out the appropriate protocol for further research. Moreover, the comparisons between various authentication techniques are also illustrated.

Comparative Study on Various Authentication Protocols in Wireless Sensor Networks

PubMed Central

Rajeswari, S. Raja; Seenivasagam, V.

2016-01-01

Wireless sensor networks (WSNs) consist of lightweight devices with low cost, low power, and short-ranged wireless communication. The sensors can communicate with each other to form a network. In WSNs, broadcast transmission is widely used along with the maximum usage of wireless networks and their applications. Hence, it has become crucial to authenticate broadcast messages. Key management is also an active research topic in WSNs. Several key management schemes have been introduced, and their benefits are not recognized in a specific WSN application. Security services are vital for ensuring the integrity, authenticity, and confidentiality of the critical information. Therefore, the authentication mechanisms are required to support these security services and to be resilient to distinct attacks. Various authentication protocols such as key management protocols, lightweight authentication protocols, and broadcast authentication protocols are compared and analyzed for all secure transmission applications. The major goal of this survey is to compare and find out the appropriate protocol for further research. Moreover, the comparisons between various authentication techniques are also illustrated. PMID:26881272

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.

Global Connections for Lasting Impressions: Experiential Learning about TCP

NASA Astrophysics Data System (ADS)

Allison, Colin; Miller, Alan; Oliver, Iain; Sturgeon, Thomas

“Tell me and I forget, Show me and I remember, Involve me and I understand”. This paper discusses the motivation for, and design of, a learning resource which allows students to explore the Transmission Control Protocol (TCP). TCP is responsible for transporting over 80% of the traffic on the Internet - all web and e-mail for example - and in addition is the primary means of achieving Internet congestion control. TCP is therefore core to modern life. It is a protocol under constant study with a view to evolution, and it is incumbent on all ICT curricula to provide education at appropriate levels about its dynamics, strengths and weaknesses. There are no shortages of good textbooks which provide information on TCP, but these are no substitute for experiential learning in order to provide a lasting understanding. The TCP Live learning resource allows students to explore the behavior of TCP on the global Internet, and see the wide variety of conditions that the protocol has to cope with, thereby extending their viewpoint outwith the limited scope of their own institutional firewalls.

RACOON: a multiuser QoS design for mobile wireless body area networks.

PubMed

Cheng, Shihheng; Huang, Chingyao; Tu, Chun Chen

2011-10-01

In this study, Random Contention-based Resource Allocation (RACOON) medium access control (MAC) protocol is proposed to support the quality of service (QoS) for multi-user mobile wireless body area networks (WBANs). Different from existing QoS designs that focus on a single WBAN, a multiuser WBAN QoS should further consider both inter-WBAN interference and inter-WBAN priorities. Similar problems have been studied in both overlapped wireless local area networks (WLANs) and Bluetooth piconets that need QoS supports. However, these solutions are designed for non-medical transmissions that do not consider any priority scheme for medical applications. Most importantly, these studies focus on only static or low mobility networks. Network mobility of WBANs will introduce unnecessary inter-network collisions and energy waste, which are not considered by these solutions. The proposed multiuser-QoS protocol, RACOON, simultaneously satisfies the inter WBAN QoS requirements and overcomes the performance degradation caused by WBAN mobility. Simulation results verify that RACOON provides better latency and energy control, as compared with WBAN QoS protocols without considering the inter-WBAN requirements.

Improving UDP/IP Transmission Without Increasing Congestion

NASA Technical Reports Server (NTRS)

Burleigh, Scott

2006-01-01

Datagram Retransmission (DGR) is a computer program that, within certain limits, ensures the reception of each datagram transmitted under the User Datagram Protocol/Internet Protocol. [User Datagram Protocol (UDP) is considered unreliable because it does not involve a reliability-ensuring connection-initiation dialogue between sender and receiver. UDP is well suited to issuing of many small messages to many different receivers.] Unlike prior software for ensuring reception of UDP datagrams, DGR does not contribute to network congestion by retransmitting data more frequently as an ever-increasing number of messages and acknowledgements is lost. Instead, DGR does just the opposite: DGR includes an adaptive timeout-interval- computing component that provides maximum opportunity for reception of acknowledgements, minimizing retransmission. By monitoring changes in the rate at which message-transmission transactions are completed, DGR detects changes in the level of congestion and responds by imposing varying degrees of delay on the transmission of new messages. In addition, DGR maximizes throughput by not waiting for acknowledgement of a message before sending the next message. All DGR communication is asynchronous, to maximize efficient utilization of network connections. DGR manages multiple concurrent datagram transmission and acknowledgement conversations.

An Experiment of GMPLS-Based Dispersion Compensation Control over In-Field Fibers

NASA Astrophysics Data System (ADS)

Seno, Shoichiro; Horiuchi, Eiichi; Yoshida, Sota; Sugihara, Takashi; Onohara, Kiyoshi; Kamei, Misato; Baba, Yoshimasa; Kubo, Kazuo; Mizuochi, Takashi

As ROADMs (Reconfigurable Optical Add/Drop Multiplexers) are becoming widely used in metro/core networks, distributed control of wavelength paths by extended GMPLS (Generalized MultiProtocol Label Switching) protocols has attracted much attention. For the automatic establishment of an arbitrary wavelength path satisfying dynamic traffic demands over a ROADM or WXC (Wavelength Cross Connect)-based network, precise determination of chromatic dispersion over the path and optimized assignment of dispersion compensation capabilities at related nodes are essential. This paper reports an experiment over in-field fibers where GMPLS-based control was applied for the automatic discovery of chromatic dispersion, path computation, and wavelength path establishment with dynamic adjustment of variable dispersion compensation. The GMPLS-based control scheme, which the authors called GMPLS-Plus, extended GMPLS's distributed control architecture with attributes for automatic discovery, advertisement, and signaling of chromatic dispersion. In this experiment, wavelength paths with distances of 24km and 360km were successfully established and error-free data transmission was verified. The experiment also confirmed path restoration with dynamic compensation adjustment upon fiber failure.

Comment on "Direct counterfactual transmission of a quantum state"

NASA Astrophysics Data System (ADS)

Vaidman, L.

2016-06-01

The protocol for counterfactual transmission of a qubit [Z.-H. Li et al., Phys. Rev. A 92, 052315 (2015), 10.1103/PhysRevA.92.052315] relies on the counterfactuality of transmissions of bit 1 and of bit 0. Since counterfactuality of transmission of bit 0 is not established, the claim of counterfactuality of transmission of a quantum state is not established too.

Effects on instruments of the World Health Organization--recommended protocols for decontamination after possible exposure to transmissible spongiform encephalopathy-contaminated tissue.

PubMed

Brown, Stanley A; Merritt, Katharine; Woods, Terry O; Busick, Deanna N

2005-01-15

It has been recommended by the World Health Organization (WHO) and Centers for Disease Control and Prevention (CDC) that rigorous decontamination protocols be used on surgical instruments that have been exposed to tissue possibly contaminated with Creutzfeldt-Jakob disease (CJD). This study was designed to examine the effects of these protocols on various types of surgical instruments. The most important conclusions are: (1) autoclaving in 1N NaOH will cause darkening of some instruments; (2) soaking in 1N NaOH at room temperature damages carbon steel but not stainless steel or titanium; (3) soaking in chlorine bleach will badly corrode gold-plated instruments and will damage some, but not all, stainless-steel instruments, especially welded and soldered joints. Damage became apparent after the first exposure and therefore long tests are not necessary to establish which instruments will be damaged. Copyright 2004 Wiley Periodicals, Inc.

A novel permeabilization protocol to obtain intracellular 3D immunolabeling for electron tomography.

PubMed

Jiménez, Nuria; Post, Jan A

2014-01-01

Electron tomography (ET) is a very important high-resolution tool for 3D imaging in cell biology. By combining the technique with immunolabeling, ET can provide essential insights into both cellular architecture and dynamics. We recently developed a protocol to achieve 3D immunolabeling of intracellular antigens without the need for uncontrolled permeabilization steps that cause random, extensive cell membrane disruption. Here we describe this novel method based on well-controlled permeabilization by targeted laser cell perforation. Mechanical permeabilization of the plasma membrane can be applied at specific sites without affecting other parts of the plasma membrane and intracellular membranes. Despite the relatively small opening created in the plasma membrane, the method allows specific 3D immunolocalization of cytoplasmic antigens in cultured cells by a pre-embedment protocol. The approach is unique and leads to a superior ultrastructural preservation for transmission electron microscopy and electron tomography.

On the Effective Evaluation of TCP

NASA Technical Reports Server (NTRS)

Allman, Mark; Falk, Aaron

2000-01-01

Understanding the performance of the Internet's Transmission Control Protocol (TCP) is important because it is the dominant protocol used in the Internet today. Various testing methods exist to evaluate TCP performance, however all have pitfalls an that need to be understood prior to obtaining useful results. Simulating TCP is difficult because of the wide range of variables, environments, and implementations available. Testing TCP modifications in the global Internet may not be the answer either: testing new protocols on real networks endangers other people's traffic and, if not done correctly, may also yield inaccurate or misleading results. In order for TCP research to be independently evaluated in the Internet research community there is a set of questions that researchers should try to answer. This paper attempts to list some of those questions and make recommendations as to how TCP testing can be structured to be provide useful answers.

Continuous variable quantum cryptography using coherent states.

PubMed

Grosshans, Frédéric; Grangier, Philippe

2002-02-04

We propose several methods for quantum key distribution (QKD) based on the generation and transmission of random distributions of coherent or squeezed states, and we show that they are secure against individual eavesdropping attacks. These protocols require that the transmission of the optical line between Alice and Bob is larger than 50%, but they do not rely on "sub-shot-noise" features such as squeezing. Their security is a direct consequence of the no-cloning theorem, which limits the signal-to-noise ratio of possible quantum measurements on the transmission line. Our approach can also be used for evaluating various QKD protocols using light with Gaussian statistics.

Dual Influence of Endocannabinoids on Long-Term Potentiation of Synaptic Transmission

PubMed Central

Silva-Cruz, Armando; Carlström, Mattias; Ribeiro, Joaquim A.; Sebastião, Ana M.

2017-01-01

Cannabinoid receptor 1 (CB1R) is widely distributed in the central nervous system, in excitatory and inhibitory neurons, and in astrocytes. CB1R agonists impair cognition and prevent long-term potentiation (LTP) of synaptic transmission, but the influence of endogenously formed cannabinoids (eCBs) on hippocampal LTP remains ambiguous. Based on the knowledge that eCBs are released upon high frequency neuronal firing, we hypothesized that the influence of eCBs upon LTP could change according to the paradigm of LTP induction. We thus tested the influence of eCBs on hippocampal LTP using two θ-burst protocols that induce either a weak or a strong LTP. LTP induced by a weak-θ-burst protocol is facilitated while preventing the endogenous activation of CB1Rs. In contrast, the same procedures lead to inhibition of LTP induced by the strong-θ-burst protocol, suggestive of a facilitatory action of eCBs upon strong LTP. Accordingly, an inhibitor of the metabolism of the predominant eCB in the hippocampus, 2-arachidonoyl-glycerol (2-AG), facilitates strong LTP. The facilitatory action of endogenous CB1R activation does not require the activity of inhibitory A1 adenosine receptors, is not affected by inhibition of astrocytic metabolism, but involves inhibitory GABAergic transmission. The continuous activation of CB1Rs via exogenous cannabinoids, or by drugs known to prevent metabolism of the non-prevalent hippocampal eCB, anandamide, inhibited LTP. We conclude that endogenous activation of CB1Rs by physiologically formed eCBs exerts a fine-tune homeostatic control of LTP in the hippocampus, acting as a high-pass filter, therefore likely reducing the signal-to-noise ratio of synaptic strengthening. PMID:29311928

Medium Access Control in Ad Hoc Networks With Omni-Directional and Directional Antennas

DTIC Science & Technology

2004-06-01

Carvalho, Marc, Hong, Long, Yong, Zhenjiang, Lei, Ravi, Saro, Hari, Ramesh, Brad, Renato and Radhika) in the Computer Communication Research Group (CCRG...which we call directional collision avoidance protocols. Ko et al. [35] propose two schemes. One scheme consists of nodes using directional RTS...different from the model assumed by Ko et al. [35] where antennas are always active for re- ceiving and thus transmissions to different antennas

Effect of Water Vapor, Temperature, and Rapid Annealing on Formamidinium Lead Triiodide Perovskite Crystallization

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

Aguiar, Jeffery A.; Wozny, Sarah; Alkurd, Nooraldeen R.

Perovskite-based solar cells are one of the emerging candidates for radically lower cost photovoltaics. Herein, we report on the synthesis and crystallization of organic-inorganic formamidinium lead triiodide perovskite films under controlled atmospheric and environmental conditions. Using in situ (scanning) transmission electron microscopy, we make observations of the crystallization process of these materials in nitrogen and oxygen gas with and without the presence of water vapor. Complementary planar samples were also fabricated in the presence of water vapor and characterized by in situ X-ray diffraction. Direct observations of the material structure and final morphology indicate that the exposure to water vapormore » results in a porous film that is metastable, regardless of the presence of argon, nitrogen, or oxygen. However, the optimal crystallization temperature of 175 degrees C is unperturbed across conditions. Rapid modulation about the annealing temperature of 175 degrees C in +/-25 degrees C steps (150-200 degrees C) promotes crystallization and significantly improves the film morphology by overcoming the presence of impregnated water trapped in the material. Following this processing protocol, we demonstrate substantial growth to micron-size grains via observation inside of an environmentally controlled transmission electron microscope. Adapting this insight from our in situ microscopy, we are able to provide an informed materials protocol to control the structure and morphology of these organic-inorganic semiconductors, which is readily applicable to benchtop device growth strategies.« less

Effect of Water Vapor, Temperature, and Rapid Annealing on Formamidinium Lead Triiodide Perovskite Crystallization

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

Aguiar, Jeffery A.; Wozny, Sarah; Alkurd, Nooraldeen R.

Perovskite-based solar cells are one of the emerging candidates for radically lower cost photovoltaics. Herein, we report on the synthesis and crystallization of organic-inorganic formamidinium lead triiodide perovskite films under controlled atmospheric and environmental conditions. Using in situ (scanning) transmission electron microscopy, we make observations of the crystallization process of these materials in nitrogen and oxygen gas with and without the presence of water vapor. Complementary planar samples were also fabricated in the presence of water vapor and characterized by in situ X-ray diffraction. Direct observations of the material structure and final morphology indicate that the exposure to water vapormore » results in a porous film that is metastable, regardless of the presence of argon, nitrogen, or oxygen. However, the optimal crystallization temperature of 175 °C is unperturbed across conditions. Rapid modulation about the annealing temperature of 175 °C in ±25 °C steps (150-200 °C) promotes crystallization and significantly improves the film morphology by overcoming the presence of impregnated water trapped in the material. Following this processing protocol, we demonstrate substantial growth to micron-size grains via observation inside of an environmentally controlled transmission electron microscope. Adapting this insight from our in situ microscopy, we are able to provide an informed materials protocol to control the structure and morphology of these organic-inorganic semiconductors, which is readily applicable to benchtop device growth strategies.« less

The Benefit of Remote Microphones Using Four Wireless Protocols.

PubMed

Rodemerk, Krishna S; Galster, Jason A

2015-09-01

Many studies have reported the speech recognition benefits of a personal remote microphone system when used by adult listeners with hearing loss. The advance of wireless technology has allowed for many wireless audio transmission protocols. Some of these protocols interface with commercially available hearing aids. As a result, commercial remote microphone systems use a variety of different protocols for wireless audio transmission. It is not known how these systems compare, with regard to adult speech recognition in noise. The primary goal of this investigation was to determine the speech recognition benefits of four different commercially available remote microphone systems, each with a different wireless audio transmission protocol. A repeated-measures design was used in this study. Sixteen adults, ages 52 to 81 yr, with mild to severe sensorineural hearing loss participated in this study. Participants were fit with three different sets of bilateral hearing aids and four commercially available remote microphone systems (FM, 900 MHz, 2.4 GHz, and Bluetooth(®) paired with near-field magnetic induction). Speech recognition scores were measured by an adaptive version of the Hearing in Noise Test (HINT). The participants were seated both 6 and 12' away from the talker loudspeaker. Participants repeated HINT sentences with and without hearing aids and with four commercially available remote microphone systems in both seated positions with and without contributions from the hearing aid or environmental microphone (24 total conditions). The HINT SNR-50, or the signal-to-noise ratio required for correct repetition of 50% of the sentences, was recorded for all conditions. A one-way repeated measures analysis of variance was used to determine statistical significance of microphone condition. The results of this study revealed that use of the remote microphone systems statistically improved speech recognition in noise relative to unaided and hearing aid-only conditions across all four wireless transmission protocols at 6 and 12' away from the talker. Participants showed a significant improvement in speech recognition in noise when comparing four remote microphone systems with different wireless transmission methods to hearing aids alone. American Academy of Audiology.

Interrupting transmission of soil-transmitted helminths: a study protocol for cluster randomised trials evaluating alternative treatment strategies and delivery systems in Kenya

PubMed Central

Brooker, Simon J; Mwandawiro, Charles S; Halliday, Katherine E; Njenga, Sammy M; Mcharo, Carlos; Gichuki, Paul M; Wasunna, Beatrice; Kihara, Jimmy H; Njomo, Doris; Alusala, Dorcas; Chiguzo, Athuman; Turner, Hugo C; Teti, Caroline; Gwayi-Chore, Claire; Nikolay, Birgit; Truscott, James E; Hollingsworth, T Déirdre; Balabanova, Dina; Griffiths, Ulla K; Freeman, Matthew C; Allen, Elizabeth; Pullan, Rachel L; Anderson, Roy M

2015-01-01

Introduction In recent years, an unprecedented emphasis has been given to the control of neglected tropical diseases, including soil-transmitted helminths (STHs). The mainstay of STH control is school-based deworming (SBD), but mathematical modelling has shown that in all but very low transmission settings, SBD is unlikely to interrupt transmission, and that new treatment strategies are required. This study seeks to answer the question: is it possible to interrupt the transmission of STH, and, if so, what is the most cost-effective treatment strategy and delivery system to achieve this goal? Methods and analysis Two cluster randomised trials are being implemented in contrasting settings in Kenya. The interventions are annual mass anthelmintic treatment delivered to preschool- and school-aged children, as part of a national SBD programme, or to entire communities, delivered by community health workers. Allocation to study group is by cluster, using predefined units used in public health provision—termed community units (CUs). CUs are randomised to one of three groups: receiving either (1) annual SBD; (2) annual community-based deworming (CBD); or (3) biannual CBD. The primary outcome measure is the prevalence of hookworm infection, assessed by four cross-sectional surveys. Secondary outcomes are prevalence of Ascaris lumbricoides and Trichuris trichiura, intensity of species infections and treatment coverage. Costs and cost-effectiveness will be evaluated. Among a random subsample of participants, worm burden and proportion of unfertilised eggs will be assessed longitudinally. A nested process evaluation, using semistructured interviews, focus group discussions and a stakeholder analysis, will investigate the community acceptability, feasibility and scale-up of each delivery system. Ethics and dissemination Study protocols have been reviewed and approved by the ethics committees of the Kenya Medical Research Institute and National Ethics Review Committee, and London School of Hygiene and Tropical Medicine. The study has a dedicated web site. Trial registration number NCT02397772. PMID:26482774

A network architecture for International Business Satellite communications

NASA Astrophysics Data System (ADS)

Takahata, Fumio; Nohara, Mitsuo; Takeuchi, Yoshio

Demand Assignment (DA) control is expected to be introduced in the International Business Satellte communications (IBS) network in order to cope with a growing international business traffic. The paper discusses the DA/IBS network from the viewpoints of network configuration, satellite channel configuration and DA control. The network configuration proposed here consists of one Central Station with network management function and several Network Coordination Stations with user management function. A satellite channel configuration is also presented along with a tradeoff study on transmission bit rate, high power amplifier output power requirement, and service quality. The DA control flow and protocol based on CCITT Signalling System No. 7 are also proposed.

Frame Transmission Efficiency-Based Cross-Layer Congestion Notification Scheme in Wireless Ad Hoc Networks.

PubMed

He, Huaguang; Li, Taoshen; Feng, Luting; Ye, Jin

2017-07-15

Different from the traditional wired network, the fundamental cause of transmission congestion in wireless ad hoc networks is medium contention. How to utilize the congestion state from the MAC (Media Access Control) layer to adjust the transmission rate is core work for transport protocol design. However, recent works have shown that the existing cross-layer congestion detection solutions are too complex to be deployed or not able to characterize the congestion accurately. We first propose a new congestion metric called frame transmission efficiency (i.e., the ratio of successful transmission delay to the frame service delay), which describes the medium contention in a fast and accurate manner. We further present the design and implementation of RECN (ECN and the ratio of successful transmission delay to the frame service delay in the MAC layer, namely, the frame transmission efficiency), a general supporting scheme that adjusts the transport sending rate through a standard ECN (Explicit Congestion Notification) signaling method. Our method can be deployed on commodity switches with small firmware updates, while making no modification on end hosts. We integrate RECN transparently (i.e., without modification) with TCP on NS2 simulation. The experimental results show that RECN remarkably improves network goodput across multiple concurrent TCP flows.

Packetized Video On MAGNET

NASA Astrophysics Data System (ADS)

Lazar, Aurel A.; White, John S.

1987-07-01

Theoretical analysis of integrated local area network model of MAGNET, an integrated network testbed developed at Columbia University, shows that the bandwidth freed up during video and voice calls during periods of little movement in the images and periods of silence in the speech signals could be utilized efficiently for graphics and data transmission. Based on these investigations, an architecture supporting adaptive protocols that are dynamicaly controlled by the requirements of a fluctuating load and changing user environment has been advanced. To further analyze the behavior of the network, a real-time packetized video system has been implemented. This system is embedded in the real-time multimedia workstation EDDY, which integrates video, voice, and data traffic flows. Protocols supporting variable-bandwidth, fixed-quality packetized video transport are described in detail.

Packetized video on MAGNET

NASA Astrophysics Data System (ADS)

Lazar, Aurel A.; White, John S.

1986-11-01

Theoretical analysis of an ILAN model of MAGNET, an integrated network testbed developed at Columbia University, shows that the bandwidth freed up by video and voice calls during periods of little movement in the images and silence periods in the speech signals could be utilized efficiently for graphics and data transmission. Based on these investigations, an architecture supporting adaptive protocols that are dynamically controlled by the requirements of a fluctuating load and changing user environment has been advanced. To further analyze the behavior of the network, a real-time packetized video system has been implemented. This system is embedded in the real time multimedia workstation EDDY that integrates video, voice and data traffic flows. Protocols supporting variable bandwidth, constant quality packetized video transport are descibed in detail.

Impact of window decrement rate on TCP performance in an adhoc network

NASA Astrophysics Data System (ADS)

Suherman; Hutasuhut, Arief T. W.; Badra, Khaldun; Al-Akaidi, Marwan

2017-09-01

Transmission control protocol (TCP) is a reliable transport protocol handling end to end connection in TCP/IP stack. It works well in copper or optical fibre link, but experiences increasing delay in wireless network. Further, TCP experiences multiple retransmissions due to higher collision probability within wireless network. The situation may get worsen in an ad hoc network. This paper examines the impact half window or window reduction rate to the overall TCP performances. The evaluation using NS-2 simulator shows that the smaller the window decrement rate results the smaller end to end delay. Delay is reduced to 17.05% in average when window decrement rate decreases. Average jitter also decreases 4.15%, while packet loss is not affected.

WEAMR — A Weighted Energy Aware Multipath Reliable Routing Mechanism for Hotline-Based WSNs

PubMed Central

Tufail, Ali; Qamar, Arslan; Khan, Adil Mehmood; Baig, Waleed Akram; Kim, Ki-Hyung

2013-01-01

Reliable source to sink communication is the most important factor for an efficient routing protocol especially in domains of military, healthcare and disaster recovery applications. We present weighted energy aware multipath reliable routing (WEAMR), a novel energy aware multipath routing protocol which utilizes hotline-assisted routing to meet such requirements for mission critical applications. The protocol reduces the number of average hops from source to destination and provides unmatched reliability as compared to well known reactive ad hoc protocols i.e., AODV and AOMDV. Our protocol makes efficient use of network paths based on weighted cost calculation and intelligently selects the best possible paths for data transmissions. The path cost calculation considers end to end number of hops, latency and minimum energy node value in the path. In case of path failure path recalculation is done efficiently with minimum latency and control packets overhead. Our evaluation shows that our proposal provides better end-to-end delivery with less routing overhead and higher packet delivery success ratio compared to AODV and AOMDV. The use of multipath also increases overall life time of WSN network using optimum energy available paths between sender and receiver in WDNs. PMID:23669714

WEAMR-a weighted energy aware multipath reliable routing mechanism for hotline-based WSNs.

PubMed

Tufail, Ali; Qamar, Arslan; Khan, Adil Mehmood; Baig, Waleed Akram; Kim, Ki-Hyung

2013-05-13

Reliable source to sink communication is the most important factor for an efficient routing protocol especially in domains of military, healthcare and disaster recovery applications. We present weighted energy aware multipath reliable routing (WEAMR), a novel energy aware multipath routing protocol which utilizes hotline-assisted routing to meet such requirements for mission critical applications. The protocol reduces the number of average hops from source to destination and provides unmatched reliability as compared to well known reactive ad hoc protocols i.e., AODV and AOMDV. Our protocol makes efficient use of network paths based on weighted cost calculation and intelligently selects the best possible paths for data transmissions. The path cost calculation considers end to end number of hops, latency and minimum energy node value in the path. In case of path failure path recalculation is done efficiently with minimum latency and control packets overhead. Our evaluation shows that our proposal provides better end-to-end delivery with less routing overhead and higher packet delivery success ratio compared to AODV and AOMDV. The use of multipath also increases overall life time of WSN network using optimum energy available paths between sender and receiver in WDNs.

An Ultra-Low Power and Flexible Acoustic Modem Design to Develop Energy-Efficient Underwater Sensor Networks

PubMed Central

Sánchez, Antonio; Blanc, Sara; Yuste, Pedro; Perles, Angel; Serrano, Juan José

2012-01-01

This paper is focused on the description of the physical layer of a new acoustic modem called ITACA. The modem architecture includes as a major novelty an ultra-low power asynchronous wake-up system implementation for underwater acoustic transmission that is based on a low-cost off-the-shelf RFID peripheral integrated circuit. This feature enables a reduced power dissipation of 10 μW in stand-by mode and registers very low power values during reception and transmission. The modem also incorporates clear channel assessment (CCA) to support CSMA-based medium access control (MAC) layer protocols. The design is part of a compact platform for a long-life short/medium range underwater wireless sensor network. PMID:22969324

An ultra-low power and flexible acoustic modem design to develop energy-efficient underwater sensor networks.

PubMed

Sánchez, Antonio; Blanc, Sara; Yuste, Pedro; Perles, Angel; Serrano, Juan José

2012-01-01

This paper is focused on the description of the physical layer of a new acoustic modem called ITACA. The modem architecture includes as a major novelty an ultra-low power asynchronous wake-up system implementation for underwater acoustic transmission that is based on a low-cost off-the-shelf RFID peripheral integrated circuit. This feature enables a reduced power dissipation of 10 μW in stand-by mode and registers very low power values during reception and transmission. The modem also incorporates clear channel assessment (CCA) to support CSMA-based medium access control (MAC) layer protocols. The design is part of a compact platform for a long-life short/medium range underwater wireless sensor network.

Telemetry Standards, RCC Standard 106-17. Chapter 24. Message Formats

DTIC Science & Technology

2017-07-01

strength indicator TCP Transmission Control Protocol TE Traffic Engineering TAI International Atomic Time TLV Type-Length-Value TmNS Telemetry...to a specific radio link. TE Queue Status Report 10 This TLV is used by a radio to report Traffic Engineering (TE) queue levels for each of the 8...24.3.2.6 Traffic Engineering Queue Status Report TLV The TE Queue Status Report TLV shall be used to report the queue levels of the eight

An On-Demand Emergency Packet Transmission Scheme for Wireless Body Area Networks.

PubMed

Al Ameen, Moshaddique; Hong, Choong Seon

2015-12-04

The rapid developments of sensor devices that can actively monitor human activities have given rise to a new field called wireless body area network (BAN). A BAN can manage devices in, on and around the human body. Major requirements of such a network are energy efficiency, long lifetime, low delay, security, etc. Traffic in a BAN can be scheduled (normal) or event-driven (emergency). Traditional media access control (MAC) protocols use duty cycling to improve performance. A sleep-wake up cycle is employed to save energy. However, this mechanism lacks features to handle emergency traffic in a prompt and immediate manner. To deliver an emergency packet, a node has to wait until the receiver is awake. It also suffers from overheads, such as idle listening, overhearing and control packet handshakes. An external radio-triggered wake up mechanism is proposed to handle prompt communication. It can reduce the overheads and improve the performance through an on-demand scheme. In this work, we present a simple-to-implement on-demand packet transmission scheme by taking into considerations the requirements of a BAN. The major concern is handling the event-based emergency traffic. The performance analysis of the proposed scheme is presented. The results showed significant improvements in the overall performance of a BAN compared to state-of-the-art protocols in terms of energy consumption, delay and lifetime.

An On-Demand Emergency Packet Transmission Scheme for Wireless Body Area Networks

PubMed Central

Al Ameen, Moshaddique; Hong, Choong Seon

2015-01-01

The rapid developments of sensor devices that can actively monitor human activities have given rise to a new field called wireless body area network (BAN). A BAN can manage devices in, on and around the human body. Major requirements of such a network are energy efficiency, long lifetime, low delay, security, etc. Traffic in a BAN can be scheduled (normal) or event-driven (emergency). Traditional media access control (MAC) protocols use duty cycling to improve performance. A sleep-wake up cycle is employed to save energy. However, this mechanism lacks features to handle emergency traffic in a prompt and immediate manner. To deliver an emergency packet, a node has to wait until the receiver is awake. It also suffers from overheads, such as idle listening, overhearing and control packet handshakes. An external radio-triggered wake up mechanism is proposed to handle prompt communication. It can reduce the overheads and improve the performance through an on-demand scheme. In this work, we present a simple-to-implement on-demand packet transmission scheme by taking into considerations the requirements of a BAN. The major concern is handling the event-based emergency traffic. The performance analysis of the proposed scheme is presented. The results showed significant improvements in the overall performance of a BAN compared to state-of-the-art protocols in terms of energy consumption, delay and lifetime. PMID:26690161

ACTS 118x: High Speed TCP Interoperability Testing

NASA Technical Reports Server (NTRS)

Brooks, David E.; Buffinton, Craig; Beering, Dave R.; Welch, Arun; Ivancic, William D.; Zernic, Mike; Hoder, Douglas J.

1999-01-01

With the recent explosion of the Internet and the enormous business opportunities available to communication system providers, great interest has developed in improving the efficiency of data transfer over satellite links using the Transmission Control Protocol (TCP) of the Internet Protocol (IP) suite. The NASA's ACTS experiments program initiated a series of TCP experiments to demonstrate scalability of TCP/IP and determine to what extent the protocol can be optimized over a 622 Mbps satellite link. Through partnerships with the government technology oriented labs, computer, telecommunication, and satellite industries NASA Glenn was able to: (1) promote the development of interoperable, high-performance TCP/IP implementations across multiple computing / operating platforms; (2) work with the satellite industry to answer outstanding questions regarding the use of standard protocols (TCP/IP and ATM) for the delivery of advanced data services, and for use in spacecraft architectures; and (3) conduct a series of TCP/IP interoperability tests over OC12 ATM over a satellite network in a multi-vendor environment using ACTS. The experiments' various network configurations and the results are presented.

Multicast Delayed Authentication For Streaming Synchrophasor Data in the Smart Grid

PubMed Central

Câmara, Sérgio; Anand, Dhananjay; Pillitteri, Victoria; Carmo, Luiz

2017-01-01

Multicast authentication of synchrophasor data is challenging due to the design requirements of Smart Grid monitoring systems such as low security overhead, tolerance of lossy networks, time-criticality and high data rates. In this work, we propose inf -TESLA, Infinite Timed Efficient Stream Loss-tolerant Authentication, a multicast delayed authentication protocol for communication links used to stream synchrophasor data for wide area control of electric power networks. Our approach is based on the authentication protocol TESLA but is augmented to accommodate high frequency transmissions of unbounded length. inf TESLA protocol utilizes the Dual Offset Key Chains mechanism to reduce authentication delay and computational cost associated with key chain commitment. We provide a description of the mechanism using two different modes for disclosing keys and demonstrate its security against a man-in-the-middle attack attempt. We compare our approach against the TESLA protocol in a 2-day simulation scenario, showing a reduction of 15.82% and 47.29% in computational cost, sender and receiver respectively, and a cumulative reduction in the communication overhead. PMID:28736582

Multicast Delayed Authentication For Streaming Synchrophasor Data in the Smart Grid.

PubMed

Câmara, Sérgio; Anand, Dhananjay; Pillitteri, Victoria; Carmo, Luiz

2016-01-01

Multicast authentication of synchrophasor data is challenging due to the design requirements of Smart Grid monitoring systems such as low security overhead, tolerance of lossy networks, time-criticality and high data rates. In this work, we propose inf -TESLA, Infinite Timed Efficient Stream Loss-tolerant Authentication, a multicast delayed authentication protocol for communication links used to stream synchrophasor data for wide area control of electric power networks. Our approach is based on the authentication protocol TESLA but is augmented to accommodate high frequency transmissions of unbounded length. inf TESLA protocol utilizes the Dual Offset Key Chains mechanism to reduce authentication delay and computational cost associated with key chain commitment. We provide a description of the mechanism using two different modes for disclosing keys and demonstrate its security against a man-in-the-middle attack attempt. We compare our approach against the TESLA protocol in a 2-day simulation scenario, showing a reduction of 15.82% and 47.29% in computational cost, sender and receiver respectively, and a cumulative reduction in the communication overhead.

Secure authentication protocol for Internet applications over CATV network

NASA Astrophysics Data System (ADS)

Chin, Le-Pond

1998-02-01

An authentication protocol is proposed in this paper to implement secure functions which include two way authentication and key management between end users and head-end. The protocol can protect transmission from frauds, attacks such as reply and wiretap. Location privacy is also achieved. A rest protocol is designed to restore the system once when systems fail. The security is verified by taking several security and privacy requirements into consideration.

Three-step semiquantum secure direct communication protocol

NASA Astrophysics Data System (ADS)

Zou, XiangFu; Qiu, DaoWen

2014-09-01

Quantum secure direct communication is the direct communication of secret messages without need for establishing a shared secret key first. In the existing schemes, quantum secure direct communication is possible only when both parties are quantum. In this paper, we construct a three-step semiquantum secure direct communication (SQSDC) protocol based on single photon sources in which the sender Alice is classical. In a semiquantum protocol, a person is termed classical if he (she) can measure, prepare and send quantum states only with the fixed orthogonal quantum basis {|0>, |1>}. The security of the proposed SQSDC protocol is guaranteed by the complete robustness of semiquantum key distribution protocols and the unconditional security of classical one-time pad encryption. Therefore, the proposed SQSDC protocol is also completely robust. Complete robustness indicates that nonzero information acquired by an eavesdropper Eve on the secret message implies the nonzero probability that the legitimate participants can find errors on the bits tested by this protocol. In the proposed protocol, we suggest a method to check Eves disturbing in the doves returning phase such that Alice does not need to announce publicly any position or their coded bits value after the photons transmission is completed. Moreover, the proposed SQSDC protocol can be implemented with the existing techniques. Compared with many quantum secure direct communication protocols, the proposed SQSDC protocol has two merits: firstly the sender only needs classical capabilities; secondly to check Eves disturbing after the transmission of quantum states, no additional classical information is needed.

Electronic-To-Optical-To-Electronic Packet-Data Conversion

NASA Technical Reports Server (NTRS)

Monacos, Steve

1996-01-01

Space-time multiplexer (STM) cell-based communication system designed to take advantage of both high throughput attainable in optical transmission links and flexibility and functionality of electronic processing, storage, and switching. Long packets segmented and transmitted optically by wavelength-division multiplexing. Performs optoelectronic and protocol conversion between electronic "store-and-forward" protocols and optical "hot-potato" protocols.

Policies and protocols for preventing transmission of HIV infection in oral health care in South Africa.

PubMed

Ogunbodede, E O; Rudolph, M J

2002-12-01

Human immunodeficiency virus (HIV) infection constitutes an unparalleled public health challenge. The unique nature of most oral health procedures, instrumentation and patient-care settings requires specific strategies and protocols aimed at preventing the transmission of HIV/AIDS between oral health care providers and patients, as well as between patients themselves. The present study investigated the level of information and training about protocols and policies for preventing the transmission of HIV/AIDS in oral health care settings in South Africa. The data collection techniques utilised available information, in-depth interviews and an open-ended questionnaire. The respondents were 20 purposively selected key informants who were senior officers for HIV/AIDS programmes and/or oral health organisations. Sixteen (80%) of the respondents reported that there were no existing oral health policies on HIV/AIDS in their health care institutions or organisations. None of the interviewees knew of any specific protocols on HIV/AIDS in the oral health care setting that emanated from South Africa. In addition, none of the dental professional associations had established an infection control committee or a support system for members who might become infected with HIV and develop AIDS. Territorial boundaries existed between sectors within the medical disciplines, as well as between the medical and oral health disciplines. Numerous general impediments were identified, such as prejudice, denial and fear, inadequate training and/or information about the infection, lack of representation and resources for policy planning, a lack of interest from the business sector, and approaching HIV/AIDS in the workplace as a 'one-time issue' Other obstacles identified included unemployment, poverty, illiteracy, disempowerment of women and inadequate communication of policies to service providers. Additional issues raised included the migrant labour systeM, complexities of language and culture, the large unstructured sex industry, high prevalence of sexually transmitted infections and lack of funding. All of these have an impact on oral health. Future policy directions identified included 'increasing access to HIV information and postexposure prophylaxis' 'shift towards care and support for those living with HIV/AIDS with emphasis on community and home-based care' and 'improving intersectoral co-ordination and collaboration'. The study demonstrated gaps in availability and access to policies and protocols on HIV/AIDS by managers and health workers. Specific strategic recommendations are made for oral health.

Minimizing the Risk of Disease Transmission in Emergency Settings: Novel In Situ Physico-Chemical Disinfection of Pathogen-Laden Hospital Wastewaters.

PubMed

Sozzi, Emanuele; Fabre, Kerline; Fesselet, Jean-François; Ebdon, James E; Taylor, Huw

2015-01-01

The operation of a health care facility, such as a cholera or Ebola treatment center in an emergency setting, results in the production of pathogen-laden wastewaters that may potentially lead to onward transmission of the disease. The research presented here evaluated the design and operation of a novel treatment system, successfully used by Médecins Sans Frontières in Haiti to disinfect CTC wastewaters in situ, eliminating the need for road haulage and disposal of the waste to a poorly-managed hazardous waste facility, thereby providing an effective barrier to disease transmission through a novel but simple sanitary intervention. The physico-chemical protocols eventually successfully treated over 600 m3 of wastewater, achieving coagulation/flocculation and disinfection by exposure to high pH (Protocol A) and low pH (Protocol B) environments, using thermotolerant coliforms as a disinfection efficacy index. In Protocol A, the addition of hydrated lime resulted in wastewater disinfection and coagulation/flocculation of suspended solids. In Protocol B, disinfection was achieved by the addition of hydrochloric acid, followed by pH neutralization and coagulation/flocculation of suspended solids using aluminum sulfate. Removal rates achieved were: COD >99%; suspended solids >90%; turbidity >90% and thermotolerant coliforms >99.9%. The proposed approach is the first known successful attempt to disinfect wastewater in a disease outbreak setting without resorting to the alternative, untested, approach of 'super chlorination' which, it has been suggested, may not consistently achieve adequate disinfection. A basic analysis of costs demonstrated a significant saving in reagent costs compared with the less reliable approach of super-chlorination. The proposed approach to in situ sanitation in cholera treatment centers and other disease outbreak settings represents a timely response to a UN call for onsite disinfection of wastewaters generated in such emergencies, and the 'Coalition for Cholera Prevention and Control' recently highlighted the research as meriting serious consideration and further study. Further applications of the method to other emergency settings are being actively explored by the authors through discussion with the World Health Organization with regards to the ongoing Ebola outbreak in West Africa, and with the UK-based NGO Oxfam with regards to excreta-borne disease management in the Philippines and Myanmar, as a component of post-disaster incremental improvements to local sanitation chains.

Software Implements a Space-Mission File-Transfer Protocol

NASA Technical Reports Server (NTRS)

Rundstrom, Kathleen; Ho, Son Q.; Levesque, Michael; Sanders, Felicia; Burleigh, Scott; Veregge, John

2004-01-01

CFDP is a computer program that implements the CCSDS (Consultative Committee for Space Data Systems) File Delivery Protocol, which is an international standard for automatic, reliable transfers of files of data between locations on Earth and in outer space. CFDP administers concurrent file transfers in both directions, delivery of data out of transmission order, reliable and unreliable transmission modes, and automatic retransmission of lost or corrupted data by use of one or more of several lost-segment-detection modes. The program also implements several data-integrity measures, including file checksums and optional cyclic redundancy checks for each protocol data unit. The metadata accompanying each file can include messages to users application programs and commands for operating on remote file systems.

Probabilistic direct counterfactual quantum communication

NASA Astrophysics Data System (ADS)

Zhang, Sheng

2017-02-01

It is striking that the quantum Zeno effect can be used to launch a direct counterfactual communication between two spatially separated parties, Alice and Bob. So far, existing protocols of this type only provide a deterministic counterfactual communication service. However, this counterfactuality should be payed at a price. Firstly, the transmission time is much longer than a classical transmission costs. Secondly, the chained-cycle structure makes them more sensitive to channel noises. Here, we extend the idea of counterfactual communication, and present a probabilistic-counterfactual quantum communication protocol, which is proved to have advantages over the deterministic ones. Moreover, the presented protocol could evolve to a deterministic one solely by adjusting the parameters of the beam splitters. Project supported by the National Natural Science Foundation of China (Grant No. 61300203).

A Narrow-Linewidth Atomic Line Filter for Free Space Quantum Key Distribution under Daytime Atmospheric Conditions

NASA Astrophysics Data System (ADS)

Brown, Justin; Woolf, David; Hensley, Joel

2016-05-01

Quantum key distribution can provide secure optical data links using the established BB84 protocol, though solar backgrounds severely limit the performance through free space. Several approaches to reduce the solar background include time-gating the photon signal, limiting the field of view through geometrical design of the optical system, and spectral rejection using interference filters. Despite optimization of these parameters, the solar background continues to dominate under daytime atmospheric conditions. We demonstrate an improved spectral filter by replacing the interference filter (Δν ~ 50 GHz) with an atomic line filter (Δν ~ 1 GHz) based on optical rotation of linearly polarized light through a warm Rb vapor. By controlling the magnetic field and the optical depth of the vapor, a spectrally narrow region can be transmitted between crossed polarizers. We find that the transmission is more complex than a single peak and evaluate peak transmission as well as a ratio of peak transmission to average transmission of the local spectrum. We compare filters containing a natural abundance of Rb with those containing isotopically pure 87 Rb and 85 Rb. A filter providing > 95 % transmission and Δν ~ 1.1 GHz is achieved.

SMS-Based Medical Diagnostic Telemetry Data Transmission Protocol for Medical Sensors

PubMed Central

Townsend, Ben; Abawajy, Jemal; Kim, Tai-Hoon

2011-01-01

People with special medical monitoring needs can, these days, be sent home and remotely monitored through the use of data logging medical sensors and a transmission base-station. While this can improve quality of life by allowing the patient to spend most of their time at home, most current technologies rely on hardwired landline technology or expensive mobile data transmissions to transmit data to a medical facility. The aim of this paper is to investigate and develop an approach to increase the freedom of a monitored patient and decrease costs by utilising mobile technologies and SMS messaging to transmit data from patient to medico. To this end, we evaluated the capabilities of SMS and propose a generic communications protocol which can work within the constraints of the SMS format, but provide the necessary redundancy and robustness to be used for the transmission of non-critical medical telemetry from data logging medical sensors. PMID:22163845

Adaptive management of energy consumption, reliability and delay of wireless sensor node: Application to IEEE 802.15.4 wireless sensor node.

PubMed

Kone, Cheick Tidjane; Mathias, Jean-Denis; De Sousa, Gil

2017-01-01

Designing a Wireless Sensor Network (WSN) to achieve a high Quality of Service (QoS) (network performance and durability) is a challenging problem. We address it by focusing on the performance of the 802.15.4 communication protocol because the IEEE 802.15.4 Standard is actually considered as one of the reference technologies in WSNs. In this paper, we propose to control the sustainable use of resources (i.e., energy consumption, reliability and timely packet transmission) of a wireless sensor node equipped with photovoltaic cells by an adaptive tuning not only of the MAC (Medium Access Control) parameters but also of the sampling frequency of the node. To do this, we use one of the existing control approaches, namely the viability theory, which aims to preserve the functions and the controls of a dynamic system in a set of desirable states. So, an analytical model, describing the evolution over time of nodal resources, is derived and used by a viability algorithm for the adaptive tuning of the IEEE 802.15.4 MAC protocol. The simulation analysis shows that our solution allows ensuring indefinitely, in the absence of hardware failure, the operations (lifetime duration, reliability and timely packet transmission) of an 802.15.4 WSN and one can temporarily increase the sampling frequency of the node beyond the regular sampling one. This latter brings advantages for agricultural and environmental applications such as precision agriculture, flood or fire prevention. Main results show that our current approach enable to send more information when critical events occur without the node runs out of energy. Finally, we argue that our approach is generic and can be applied to other types of WSN.

Guaranteeing synchronous message deadlines with the timed token medium access control protocol

NASA Technical Reports Server (NTRS)

Agrawal, Gopal; Chen, Baio; Zhao, Wei; Davari, Sadegh

1992-01-01

We study the problem of guaranteeing synchronous message deadlines in token ring networks where the timed token medium access control protocol is employed. Synchronous capacity, defined as the maximum time for which a node can transmit its synchronous messages every time it receives the token, is a key parameter in the control of synchronous message transmission. To ensure the transmission of synchronous messages before their deadlines, synchronous capacities must be properly allocated to individual nodes. We address the issue of appropriate allocation of the synchronous capacities. Several synchronous capacity allocation schemes are analyzed in terms of their ability to satisfy deadline constraints of synchronous messages. We show that an inappropriate allocation of the synchronous capacities could cause message deadlines to be missed even if the synchronous traffic is extremely low. We propose a scheme called the normalized proportional allocation scheme which can guarantee the synchronous message deadlines for synchronous traffic of up to 33 percent of available utilization. To date, no other synchronous capacity allocation scheme has been reported to achieve such substantial performance. Another major contribution of this paper is an extension to the previous work on the bounded token rotation time. We prove that the time elapsed between any consecutive visits to a particular node is bounded by upsilon TTRT, where TTRT is the target token rotation time set up at system initialization time. The previous result by Johnson and Sevcik is a special case where upsilon = 2. We use this result in the analysis of various synchronous allocation schemes. It can also be applied in other similar studies.

SATNET development and operation. Pluribus satellite IMP development. Remote site maintenance. Internet operations and maintenance. Mobile access terminal network. TCP for the HP3000. TCP-TAC. TCP for VAX-UNIX. Combined quarterly technical report

NASA Astrophysics Data System (ADS)

Bressler, R. D.

1981-11-01

This quarterly technical report describes work on the development of and experimentation with packet broadcast by satellite; on development of Pluribus Satellite IMPs; on a study of the technology of Remote Site Maintenance; on Internetwork monitoring; on shipboard satellite communications; and on the development of Transmission Control Protocols for the HP3000, TAC, and VAX-UNIX.

156 Mbps Ultrahigh-Speed Wireless LAN Prototype in the 38 GHz Band

NASA Astrophysics Data System (ADS)

Wu, Gang; Inoue, Masugi; Murakami, Homare; Hase, Yoshihiro

2001-12-01

This paper describes a 156 Mbps ultrahigh-speed wireless LAN operating in the 38 GHz millimeter (mm)-wave band. The system is a third prototype developed at the Communications Research Laboratory since 1998. Compared with the previous prototypes, the system is faster (156 Mbps) and smaller (volume of radio transceiver less than 1000 cc), it has a larger service area (two overlapping basic service sets), and a longer transmission distance (the protocol can support a distance of more than two hundred meters). The development is focused on the physical layer and the data link control layer, and thus a GMSK-based mm-wave transceiver and an enhanced RS-ISMA (reservation-based slotted idle signal multiple access) protocol are key development components. This paper describes the prototype system's design, configuration, and implementation.

TCP/IP Interface for the Satellite Orbit Analysis Program (SOAP)

NASA Technical Reports Server (NTRS)

Carnright, Robert; Stodden, David; Coggi, John

2009-01-01

The Transmission Control Protocol/ Internet protocol (TCP/IP) interface for the Satellite Orbit Analysis Program (SOAP) provides the means for the software to establish real-time interfaces with other software. Such interfaces can operate between two programs, either on the same computer or on different computers joined by a network. The SOAP TCP/IP module employs a client/server interface where SOAP is the server and other applications can be clients. Real-time interfaces between software offer a number of advantages over embedding all of the common functionality within a single program. One advantage is that they allow each program to divide the computation labor between processors or computers running the separate applications. Secondly, each program can be allowed to provide its own expertise domain with other programs able to use this expertise.

Microwave-to-optical frequency conversion with a Rydberg atom coupled to a coplanar waveguide

NASA Astrophysics Data System (ADS)

Gard, Bryan; Jacobs, Kurt; McDermott, Robert; Saffman, Mark

2017-04-01

A primary candidate for converting quantum information from microwave to optical frequencies is the use of Rydberg states of a single atom trapped near a surface. The fact that the Rydberg states possess both large electric dipole moments and microwave transition frequencies allows them to interact with superconducting mesoscopic circuits. By considering a concrete example, that of a Cesium atom, and using numerical search methods to optimize the control protocols, we determine the fidelities and transmission rates that could be achievable with such a device. We show that while protocols that exploit the adiabatic STIRAP mechanism provide the best raw transfer fidelities, the fastest communication speeds can be obtained by using heralding, which allows one to remove the adiabatic constraint. Support from Oak Ridge Associated Universities.

ISS and STS Commercial Off-the-Shelf Router Testing

NASA Technical Reports Server (NTRS)

Ivancie, William D.; Bell, Terry L.; Shell, Dan

2002-01-01

This report documents the results of testing performed with commercial off-the-shelf (COTS) routers and Internet Protocols (IPs) to determine if COTS equipment and IP could be utilized to upgrade NASA's current Space Transportation System (STS), the Shuttle, and the International Space Station communication infrastructure. Testing was performed by NASA Glenn Research Center (GRC) personnel within the Electronic Systems Test Laboratory (ESTE) with cooperation from the Mission Operations Directorate (MOD) Qualification and Utilization of Electronic System Technology (QUEST) personnel. The ESTE testing occurred between November 1 and 9, 2000. Additional testing was performed at NASA Glenn Research Center in a laboratory environment with equipment configured to emulate the STS. This report documents those tests and includes detailed test procedures, equipment interface requirements, test configurations and test results. The tests showed that a COTS router and standard Transmission Control Protocols and Internet Protocols (TCP/IP) could be used for both the Shuttle and the Space Station if near-error-free radio links are provided.

Optical Circuit Switched Protocol

NASA Technical Reports Server (NTRS)

Monacos, Steve P. (Inventor)

2000-01-01

The present invention is a system and method embodied in an optical circuit switched protocol for the transmission of data through a network. The optical circuit switched protocol is an all-optical circuit switched network and includes novel optical switching nodes for transmitting optical data packets within a network. Each optical switching node comprises a detector for receiving the header, header detection logic for translating the header into routing information and eliminating the header, and a controller for receiving the routing information and configuring an all optical path within the node. The all optical path located within the node is solely an optical path without having electronic storage of the data and without having optical delay of the data. Since electronic storage of the header is not necessary and the initial header is eliminated by the first detector of the first switching node. multiple identical headers are sent throughout the network so that subsequent switching nodes can receive and read the header for setting up an optical data path.

Delay Tolerant Networking - Bundle Protocol Simulation

NASA Technical Reports Server (NTRS)

SeGui, John; Jenning, Esther

2006-01-01

In this paper, we report on the addition of MACHETE models needed to support DTN, namely: the Bundle Protocol (BP) model. To illustrate the useof MACHETE with the additional DTN model, we provide an example simulation to benchmark its performance. We demonstrate the use of the DTN protocol and discuss statistics gathered concerning the total time needed to simulate numerous bundle transmissions.

Two-party quantum key agreement protocols under collective noise channel

NASA Astrophysics Data System (ADS)

Gao, Hao; Chen, Xiao-Guang; Qian, Song-Rong

2018-06-01

Recently, quantum communication has become a very popular research field. The quantum key agreement (QKA) plays an important role in the field of quantum communication, based on its unconditional security in terms of theory. Among all kinds of QKA protocols, QKA protocols resisting collective noise are widely being studied. In this paper, we propose improved two-party QKA protocols resisting collective noise and present a feasible plan for information reconciliation. Our protocols' qubit efficiency has achieved 26.67%, which is the best among all the two-party QKA protocols against collective noise, thus showing that our protocol can improve the transmission efficiency of quantum key agreement.

Security of quantum key distribution with iterative sifting

NASA Astrophysics Data System (ADS)

Tamaki, Kiyoshi; Lo, Hoi-Kwong; Mizutani, Akihiro; Kato, Go; Lim, Charles Ci Wen; Azuma, Koji; Curty, Marcos

2018-01-01

Several quantum key distribution (QKD) protocols employ iterative sifting. After each quantum transmission round, Alice and Bob disclose part of their setting information (including their basis choices) for the detected signals. This quantum phase then ends when the basis dependent termination conditions are met, i.e., the numbers of detected signals per basis exceed certain pre-agreed threshold values. Recently, however, Pfister et al (2016 New J. Phys. 18 053001) showed that the basis dependent termination condition makes QKD insecure, especially in the finite key regime, and they suggested to disclose all the setting information after finishing the quantum phase. However, this protocol has two main drawbacks: it requires that Alice possesses a large memory, and she also needs to have some a priori knowledge about the transmission rate of the quantum channel. Here we solve these two problems by introducing a basis-independent termination condition to the iterative sifting in the finite key regime. The use of this condition, in combination with Azuma’s inequality, provides a precise estimation on the amount of privacy amplification that needs to be applied, thus leading to the security of QKD protocols, including the loss-tolerant protocol (Tamaki et al 2014 Phys. Rev. A 90 052314), with iterative sifting. Our analysis indicates that to announce the basis information after each quantum transmission round does not compromise the key generation rate of the loss-tolerant protocol. Our result allows the implementation of wider classes of classical post-processing techniques in QKD with quantified security.

Modeling and Simulation of a Novel Relay Node Based Secure Routing Protocol Using Multiple Mobile Sink for Wireless Sensor Networks.

PubMed

Perumal, Madhumathy; Dhandapani, Sivakumar

2015-01-01

Data gathering and optimal path selection for wireless sensor networks (WSN) using existing protocols result in collision. Increase in collision further increases the possibility of packet drop. Thus there is a necessity to eliminate collision during data aggregation. Increasing the efficiency is the need of the hour with maximum security. This paper is an effort to come up with a reliable and energy efficient WSN routing and secure protocol with minimum delay. This technique is named as relay node based secure routing protocol for multiple mobile sink (RSRPMS). This protocol finds the rendezvous point for optimal transmission of data using a "splitting tree" technique in tree-shaped network topology and then to determine all the subsequent positions of a sink the "Biased Random Walk" model is used. In case of an event, the sink gathers the data from all sources, when they are in the sensing range of rendezvous point. Otherwise relay node is selected from its neighbor to transfer packets from rendezvous point to sink. A symmetric key cryptography is used for secure transmission. The proposed relay node based secure routing protocol for multiple mobile sink (RSRPMS) is experimented and simulation results are compared with Intelligent Agent-Based Routing (IAR) protocol to prove that there is increase in the network lifetime compared with other routing protocols.

Achieving High Throughput for Data Transfer over ATM Networks

NASA Technical Reports Server (NTRS)

Johnson, Marjory J.; Townsend, Jeffrey N.

1996-01-01

File-transfer rates for ftp are often reported to be relatively slow, compared to the raw bandwidth available in emerging gigabit networks. While a major bottleneck is disk I/O, protocol issues impact performance as well. Ftp was developed and optimized for use over the TCP/IP protocol stack of the Internet. However, TCP has been shown to run inefficiently over ATM. In an effort to maximize network throughput, data-transfer protocols can be developed to run over UDP or directly over IP, rather than over TCP. If error-free transmission is required, techniques for achieving reliable transmission can be included as part of the transfer protocol. However, selected image-processing applications can tolerate a low level of errors in images that are transmitted over a network. In this paper we report on experimental work to develop a high-throughput protocol for unreliable data transfer over ATM networks. We attempt to maximize throughput by keeping the communications pipe full, but still keep packet loss under five percent. We use the Bay Area Gigabit Network Testbed as our experimental platform.

Application of SNMP on CATV

NASA Astrophysics Data System (ADS)

Huang, Hong-bin; Liu, Wei-ping; Chen, Shun-er; Zheng, Liming

2005-02-01

A new type of CATV network management system developed by universal MCU, which supports SNMP, is proposed in this paper. From the point of view in both hardware and software, the function and method of every modules inside the system, which include communications in the physical layer, protocol process, data process, and etc, are analyzed. In our design, the management system takes IP MAN as data transmission channel and every controlled object in the management structure has a SNMP agent. In the SNMP agent developed, there are four function modules, including physical layer communication module, protocol process module, internal data process module and MIB management module. In the paper, the structure and function of every module are designed and demonstrated while the related hardware circuit, software flow as well as the experimental results are tested. Furthermore, by introducing RTOS into the software programming, the universal MCU procedure can conducts such multi-thread management as fast Ethernet controller driving, TCP/IP process, serial port signal monitoring and so on, which greatly improves efficiency of CPU.

Space station communications and tracking equipment management/control system

NASA Technical Reports Server (NTRS)

Kapell, M. H.; Seyl, J. W.

1982-01-01

Design details of a communications and tracking (C and T) local area network and the distribution system requirements for the prospective space station are described. The hardware will be constructed of LRUs, including those for baseband, RF, and antenna subsystems. It is noted that the C and T equipment must be routed throughout the station to accommodate growth of the station. Configurations of the C and T modules will therefore be dependent on the function of the space station module where they are located. A block diagram is provided of a sample C and T hardware distribution configuration. A topology and protocol will be needed to accommodate new terminals, wide bandwidths, bidirectional message transmission, and distributed functioning. Consideration will be given to collisions occurring in the data transmission channels.

Nanostructure Sensing and Transmission of Gas Data

NASA Technical Reports Server (NTRS)

Li, Jing (Inventor)

2011-01-01

A system for receiving, analyzing and communicating results of sensing chemical and/or physical parameter values, using wireless transmission of the data. Presence or absence of one or more of a group of selected chemicals in a gas or vapor is determined, using suitably functionalized carbon nanostructures that are exposed to the gas. One or more physical parameter values, such as temperature, vapor pressure, relative humidity and distance from a reference location, are also sensed for the gas, using nanostructures and/or microstructures. All parameter values are transmitted wirelessly to a data processing site or to a control site, using an interleaving pattern for data received from different sensor groups, using I.E.E.E. 802.11 or 802.15 protocol, for example. Methods for estimating chemical concentration are discussed.

A Secure, Intelligent, and Smart-Sensing Approach for Industrial System Automation and Transmission over Unsecured Wireless Networks

PubMed Central

Shahzad, Aamir; Lee, Malrey; Xiong, Neal Naixue; Jeong, Gisung; Lee, Young-Keun; Choi, Jae-Young; Mahesar, Abdul Wheed; Ahmad, Iftikhar

2016-01-01

In Industrial systems, Supervisory control and data acquisition (SCADA) system, the pseudo-transport layer of the distributed network protocol (DNP3) performs the functions of the transport layer and network layer of the open systems interconnection (OSI) model. This study used a simulation design of water pumping system, in-which the network nodes are directly and wirelessly connected with sensors, and are monitored by the main controller, as part of the wireless SCADA system. This study also intends to focus on the security issues inherent in the pseudo-transport layer of the DNP3 protocol. During disassembly and reassembling processes, the pseudo-transport layer keeps track of the bytes sequence. However, no mechanism is available that can verify the message or maintain the integrity of the bytes in the bytes received/transmitted from/to the data link layer or in the send/respond from the main controller/sensors. To properly and sequentially keep track of the bytes, a mechanism is required that can perform verification while bytes are received/transmitted from/to the lower layer of the DNP3 protocol or the send/respond to/from field sensors. For security and byte verification purposes, a mechanism needs to be proposed for the pseudo-transport layer, by employing cryptography algorithm. A dynamic choice security buffer (SB) is designed and employed during the security development. To achieve the desired goals of the proposed study, a pseudo-transport layer stack model is designed using the DNP3 protocol open library and the security is deployed and tested, without changing the original design. PMID:26950129

A Secure, Intelligent, and Smart-Sensing Approach for Industrial System Automation and Transmission over Unsecured Wireless Networks.

PubMed

Shahzad, Aamir; Lee, Malrey; Xiong, Neal Naixue; Jeong, Gisung; Lee, Young-Keun; Choi, Jae-Young; Mahesar, Abdul Wheed; Ahmad, Iftikhar

2016-03-03

In Industrial systems, Supervisory control and data acquisition (SCADA) system, the pseudo-transport layer of the distributed network protocol (DNP3) performs the functions of the transport layer and network layer of the open systems interconnection (OSI) model. This study used a simulation design of water pumping system, in-which the network nodes are directly and wirelessly connected with sensors, and are monitored by the main controller, as part of the wireless SCADA system. This study also intends to focus on the security issues inherent in the pseudo-transport layer of the DNP3 protocol. During disassembly and reassembling processes, the pseudo-transport layer keeps track of the bytes sequence. However, no mechanism is available that can verify the message or maintain the integrity of the bytes in the bytes received/transmitted from/to the data link layer or in the send/respond from the main controller/sensors. To properly and sequentially keep track of the bytes, a mechanism is required that can perform verification while bytes are received/transmitted from/to the lower layer of the DNP3 protocol or the send/respond to/from field sensors. For security and byte verification purposes, a mechanism needs to be proposed for the pseudo-transport layer, by employing cryptography algorithm. A dynamic choice security buffer (SB) is designed and employed during the security development. To achieve the desired goals of the proposed study, a pseudo-transport layer stack model is designed using the DNP3 protocol open library and the security is deployed and tested, without changing the original design.

Preventing disease transmission by deceased tissue donors by testing blood for viral nucleic acid.

PubMed

Strong, D Michael; Nelson, Karen; Pierce, Marge; Stramer, Susan L

2005-01-01

Nucleic acid testing (NAT) has reduced the risk of transmitting infectious disease through blood transfusion. Currently NAT for HIV-1 and HCV are FDA licensed and performed by nearly all blood collection facilities, but HBV NAT is performed under an investigational study protocol. Residual risk estimates indicate that NAT could potentially reduce disease transmission through transplanted tissue. However, tissue donor samples obtained post-mortem have the potential to produce an invalid NAT result due to inhibition of amplification reactions by hemolysis and other factors. The studies reported here summarize the development of protocols to allow NAT of deceased donor samples with reduced rates of invalid results. Using these protocols, inventories from two tissue centers were tested with greater than 99% of samples producing a valid test result.

An agenda-based routing protocol in delay tolerant mobile sensor networks.

PubMed

Wang, Xiao-Min; Zhu, Jin-Qi; Liu, Ming; Gong, Hai-Gang

2010-01-01

Routing in delay tolerant mobile sensor networks (DTMSNs) is challenging due to the networks' intermittent connectivity. Most existing routing protocols for DTMSNs use simplistic random mobility models for algorithm design and performance evaluation. In the real world, however, due to the unique characteristics of human mobility, currently existing random mobility models may not work well in environments where mobile sensor units are carried (such as DTMSNs). Taking a person's social activities into consideration, in this paper, we seek to improve DTMSN routing in terms of social structure and propose an agenda based routing protocol (ARP). In ARP, humans are classified based on their agendas and data transmission is made according to sensor nodes' transmission rankings. The effectiveness of ARP is demonstrated through comprehensive simulation studies.

Design and performance evaluation of an OpenFlow-based control plane for software-defined elastic optical networks with direct-detection optical OFDM (DDO-OFDM) transmission.

PubMed

Liu, Lei; Peng, Wei-Ren; Casellas, Ramon; Tsuritani, Takehiro; Morita, Itsuro; Martínez, Ricardo; Muñoz, Raül; Yoo, S J B

2014-01-13

Optical Orthogonal Frequency Division Multiplexing (O-OFDM), which transmits high speed optical signals using multiple spectrally overlapped lower-speed subcarriers, is a promising candidate for supporting future elastic optical networks. In contrast to previous works which focus on Coherent Optical OFDM (CO-OFDM), in this paper, we consider the direct-detection optical OFDM (DDO-OFDM) as the transport technique, which leads to simpler hardware and software realizations, potentially offering a low-cost solution for elastic optical networks, especially in metro networks, and short or medium distance core networks. Based on this network scenario, we design and deploy a software-defined networking (SDN) control plane enabled by extending OpenFlow, detailing the network architecture, the routing and spectrum assignment algorithm, OpenFlow protocol extensions and the experimental validation. To the best of our knowledge, it is the first time that an OpenFlow-based control plane is reported and its performance is quantitatively measured in an elastic optical network with DDO-OFDM transmission.

Joint Cross-Layer Design for Wireless QoS Content Delivery

NASA Astrophysics Data System (ADS)

Chen, Jie; Lv, Tiejun; Zheng, Haitao

2005-12-01

In this paper, we propose a joint cross-layer design for wireless quality-of-service (QoS) content delivery. Central to our proposed cross-layer design is the concept of adaptation. Adaptation represents the ability to adjust protocol stacks and applications to respond to channel variations. We focus our cross-layer design especially on the application, media access control (MAC), and physical layers. The network is designed based on our proposed fast frequency-hopping orthogonal frequency division multiplex (OFDM) technique. We also propose a QoS-awareness scheduler and a power adaptation transmission scheme operating at both the base station and mobile sides. The proposed MAC scheduler coordinates the transmissions of an IP base station and mobile nodes. The scheduler also selects appropriate transmission formats and packet priorities for individual users based on current channel conditions and the users' QoS requirements. The test results show that our cross-layer design provides an excellent framework for wireless QoS content delivery.

Real-time distributed scheduling algorithm for supporting QoS over WDM networks

NASA Astrophysics Data System (ADS)

Kam, Anthony C.; Siu, Kai-Yeung

1998-10-01

Most existing or proposed WDM networks employ circuit switching, typically with one session having exclusive use of one entire wavelength. Consequently they are not suitable for data applications involving bursty traffic patterns. The MIT AON Consortium has developed an all-optical LAN/MAN testbed which provides time-slotted WDM service and employs fast-tunable transceivers in each optical terminal. In this paper, we explore extensions of this service to achieve fine-grained statistical multiplexing with different virtual circuits time-sharing the wavelengths in a fair manner. In particular, we develop a real-time distributed protocol for best-effort traffic over this time-slotted WDM service with near-optical fairness and throughput characteristics. As an additional design feature, our protocol supports the allocation of guaranteed bandwidths to selected connections. This feature acts as a first step towards supporting integrated services and quality-of-service guarantees over WDM networks. To achieve high throughput, our approach is based on scheduling transmissions, as opposed to collision- based schemes. Our distributed protocol involves one MAN scheduler and several LAN schedulers (one per LAN) in a master-slave arrangement. Because of propagation delays and limits on control channel capacities, all schedulers are designed to work with partial, delayed traffic information. Our distributed protocol is of the `greedy' type to ensure fast execution in real-time in response to dynamic traffic changes. It employs a hybrid form of rate and credit control for resource allocation. We have performed extensive simulations, which show that our protocol allocates resources (transmitters, receivers, wavelengths) fairly with high throughput, and supports bandwidth guarantees.

Achieving Fair Throughput among TCP Flows in Multi-Hop Wireless Mesh Networks

NASA Astrophysics Data System (ADS)

Hou, Ting-Chao; Hsu, Chih-Wei

Previous research shows that the IEEE 802.11 DCF channel contention mechanism is not capable of providing throughput fairness among nodes in different locations of the wireless mesh network. The node nearest the gateway will always strive for the chance to transmit data, causing fewer transmission opportunities for the nodes farther from the gateway, resulting in starvation. Prior studies modify the DCF mechanism to address the fairness problem. This paper focuses on the fairness study when TCP flows are carried over wireless mesh networks. By not modifying lower layer protocols, the current work identifies TCP parameters that impact throughput fairness and proposes adjusting those parameters to reduce frame collisions and improve throughput fairness. With the aid of mathematical formulation and ns2 simulations, this study finds that frame transmission from each node can be effectively controlled by properly controlling the delayed ACK timer and using a suitable advertised window. The proposed method reduces frame collisions and greatly improves TCP throughput fairness.

Seven years of clinical experience with teleconsultation in craniomaxillofacial surgery.

PubMed

Ewers, Rolf; Schicho, Kurt; Wagner, Arne; Undt, Gerhard; Seemann, Rudolf; Figl, Michael; Truppe, Michael

2005-10-01

In this work the experiences from 50 telemedically supported treatments in craniomaxillofacial surgery are summarized and different setups for their technical realization are described. Furthermore, for the first time the innovative UMTS (universal mobile telecommunication system) is applied for the transmission of arthroscopic videos of the temporomandibular joint and other craniomaxillofacial structures. The combination of computer-assisted navigation technology in augmented reality environments with telecommunication is used for execution of interactive stereotaxic teleconsultation. Furthermore, treatments without navigation are telemedically supported. This study is composed of 4 technical system configurations: 1) integrated services digital network (ISDN)-based videoconferencing without remote control of the navigation computer; 2) transmission control protocol/internet protocol (TCP/IP)-based interactive teleconsultation via bundled ISDN lines (including remote control of the navigation computer); 3) TCP/IP-based interactive teleconsultation via network; 4) combination of TCP/IP-connection and ISDN-based videoconferencing. The telemedically supported treatments are: orbitozygomatic osteotomies, positioning of the mandibular condyle in orthognathic surgery, insertion of implants, positioning of the maxilla in orthognathic surgery, distraction osteogenesis, arthroscopies of the temporomandibular joint, and operation simulations on stereolithographic models. The surgical interventions are evaluated on a 5-level system performance scale from the technical point of view. In a separate trial 20 videosequences of arthroscopies of the temporomandibular joint are transmitted via UMTS cellular phones and independently evaluated by 3 experts (ie, a total of 60 streamings) to investigate feasibility of this technology in the field of craniomaxillofacial surgery. In the years from 1996 to 2002 a total of 50 treatments were telemedically supported. All intraoperative applications were successfully finished; 48 of 60 UMTS transmissions were finished without any interruptions in constant quality, slight interruptions were observed in 8 tests, and a complete breakdown was observed during 4 streamings that required a restart of the transmission. Resolution was sufficient to diagnose even tiny anatomic structures inside the temporomandibular joint, but orientation was hardly recognizable. In many applications telecommunication technology can contribute to a quality improvement in cranio- and maxillofacial surgery because of the global availability of specialized knowledge. The required technical expenditure for teleconsultation crucially depends on the infrastructure that is already available at the clinic and the remote site. UMTS is a promising technology with the potential to be valuable in numerous craniomaxillofacial applications.

The AWED trial (Applying Wolbachia to Eliminate Dengue) to assess the efficacy of Wolbachia-infected mosquito deployments to reduce dengue incidence in Yogyakarta, Indonesia: study protocol for a cluster randomised controlled trial.

PubMed

Anders, Katherine L; Indriani, Citra; Ahmad, Riris Andono; Tantowijoyo, Warsito; Arguni, Eggi; Andari, Bekti; Jewell, Nicholas P; Rances, Edwige; O'Neill, Scott L; Simmons, Cameron P; Utarini, Adi

2018-05-31

Dengue and other arboviruses transmitted by Aedes aegypti mosquitoes, including Zika and chikungunya, present an increasing public health challenge in tropical regions. Current vector control strategies have failed to curb disease transmission, but continue to be employed despite the absence of robust evidence for their effectiveness or optimal implementation. The World Mosquito Program has developed a novel approach to arbovirus control using Ae. aegypti stably transfected with Wolbachia bacterium, with a significantly reduced ability to transmit dengue, Zika and chikungunya in laboratory experiments. Modelling predicts this will translate to local elimination of dengue in most epidemiological settings. This study protocol describes the first trial to measure the efficacy of Wolbachia in reducing dengue virus transmission in the field. The study is a parallel, two-arm, non-blinded cluster randomised controlled trial conducted in a single site in Yogyakarta, Indonesia. The aim is to determine whether large-scale deployment of Wolbachia-infected Ae. aegypti mosquitoes leads to a measurable reduction in dengue incidence in treated versus untreated areas. The primary endpoint is symptomatic, virologically confirmed dengue virus infection of any severity. The 26 km 2 study area was subdivided into 24 contiguous clusters, allocated randomly 1:1 to receive Wolbachia deployments or no intervention. We use a novel epidemiological study design, the cluster-randomised test-negative design trial, in which dengue cases and arbovirus-negative controls are sampled concurrently from among febrile patients presenting to a network of primary care clinics, with case or control status classified retrospectively based on the results of laboratory diagnostic testing. Efficacy is estimated from the odds ratio of Wolbachia exposure distribution (probability of living in a Wolbachia-treated area) among virologically confirmed dengue cases compared to test-negative controls. A secondary per-protocol analysis allows for individual Wolbachia exposure levels to be assessed to account for movements outside the cluster and the heterogeneity in local Wolbachia prevalence among treated clusters. The findings from this study will provide the first experimental evidence for the efficacy of Wolbachia in reducing dengue incidence. Together with observational evidence that is accumulating from pragmatic deployments of Wolbachia in other field sites, this will provide valuable data to estimate the effectiveness of this novel approach to arbovirus control, inform future cost-effectiveness estimates, and guide plans for large-scale deployments in other endemic settings. ClinicalTrials.gov, identifier: NCT03055585 . Registered on 14 February 2017.

Interrupting transmission of soil-transmitted helminths: a study protocol for cluster randomised trials evaluating alternative treatment strategies and delivery systems in Kenya.

PubMed

Brooker, Simon J; Mwandawiro, Charles S; Halliday, Katherine E; Njenga, Sammy M; Mcharo, Carlos; Gichuki, Paul M; Wasunna, Beatrice; Kihara, Jimmy H; Njomo, Doris; Alusala, Dorcas; Chiguzo, Athuman; Turner, Hugo C; Teti, Caroline; Gwayi-Chore, Claire; Nikolay, Birgit; Truscott, James E; Hollingsworth, T Déirdre; Balabanova, Dina; Griffiths, Ulla K; Freeman, Matthew C; Allen, Elizabeth; Pullan, Rachel L; Anderson, Roy M

2015-10-19

In recent years, an unprecedented emphasis has been given to the control of neglected tropical diseases, including soil-transmitted helminths (STHs). The mainstay of STH control is school-based deworming (SBD), but mathematical modelling has shown that in all but very low transmission settings, SBD is unlikely to interrupt transmission, and that new treatment strategies are required. This study seeks to answer the question: is it possible to interrupt the transmission of STH, and, if so, what is the most cost-effective treatment strategy and delivery system to achieve this goal? Two cluster randomised trials are being implemented in contrasting settings in Kenya. The interventions are annual mass anthelmintic treatment delivered to preschool- and school-aged children, as part of a national SBD programme, or to entire communities, delivered by community health workers. Allocation to study group is by cluster, using predefined units used in public health provision-termed community units (CUs). CUs are randomised to one of three groups: receiving either (1) annual SBD; (2) annual community-based deworming (CBD); or (3) biannual CBD. The primary outcome measure is the prevalence of hookworm infection, assessed by four cross-sectional surveys. Secondary outcomes are prevalence of Ascaris lumbricoides and Trichuris trichiura, intensity of species infections and treatment coverage. Costs and cost-effectiveness will be evaluated. Among a random subsample of participants, worm burden and proportion of unfertilised eggs will be assessed longitudinally. A nested process evaluation, using semistructured interviews, focus group discussions and a stakeholder analysis, will investigate the community acceptability, feasibility and scale-up of each delivery system. Study protocols have been reviewed and approved by the ethics committees of the Kenya Medical Research Institute and National Ethics Review Committee, and London School of Hygiene and Tropical Medicine. The study has a dedicated web site. NCT02397772. 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.

Transmission of ESBL-producing Enterobacteriaceae and their mobile genetic elements—identification of sources by whole genome sequencing: study protocol for an observational study in Switzerland

PubMed Central

Stadler, Tanja; Meinel, Dominik; Aguilar-Bultet, Lisandra; Huisman, Jana S; Schindler, Ruth; Egli, Adrian; Seth-Smith, Helena M B; Eichenberger, Lucas; Brodmann, Peter; Hübner, Philipp; Bagutti, Claudia; Tschudin-Sutter, Sarah

2018-01-01

Introduction Extended-spectrum beta-lactamases (ESBL)-producing Enterobacteriaceae were first described in relation with hospital-acquired infections. In the 2000s, the epidemiology of ESBL-producing organisms changed as especially ESBL-producing Escherichia coli was increasingly described as an important cause of community-acquired infections, supporting the hypothesis that in more recent years ESBL-producing Enterobacteriaceae have probably been imported into hospitals rather than vice versa. Transmission of ESBL-producing Enterobacteriaceae is complicated by ESBL genes being encoded on self-transmissible plasmids, which can be exchanged among the same and different bacterial species. The aim of this research project is to quantify hospital-wide transmission of ESBL-producing Enterobacteriaceae on both the level of bacterial species and the mobile genetic elements and to determine if hospital-acquired infections caused by ESBL producers are related to strains and mobile genetic elements predominantly circulating in the community or in the healthcare setting. This distinction is critical in prevention since the former emphasises the urgent need to establish or reinforce antibiotic stewardship programmes, and the latter would call for more rigorous infection control. Methods and analysis This protocol presents an observational study that will be performed at the University Hospital Basel and in the city of Basel, Switzerland. ESBL-producing Enterobacteriaceae will be collected from any specimens obtained by routine clinical practice or by active screening in both inpatient and outpatient settings, as well as from wastewater samples and foodstuffs, both collected monthly over a 12-month period for analyses by whole genome sequencing. Bacterial chromosomal, plasmid and ESBL-gene sequences will be compared within the cohort to determine genetic relatedness and migration between humans and their environment. Ethics and dissemination This study has been approved by the local ethics committee (Ethikkommission Nordwest-und Zentralschweiz) as a quality control project (Project-ID 2017–00100). The results of this study will be published in peer-reviewed medical journals, communicated to participants, the general public and all relevant stakeholders. PMID:29455172

Performance evaluation of complete data transfer of physical layer according to IEEE 802.15.4 standard

NASA Astrophysics Data System (ADS)

Raju, Kota Solomon; Merugu, Naresh Babu; Neetu, Babu, E. Ram

2016-03-01

ZigBee is well-accepted industrial standard for wireless sensor networks based on IEEE 802.15.4 standard. Wireless Sensor Networks is the major concern of communication these days. These Wireless Sensor Networks investigate the properties of networks of small battery-powered sensors with wireless communication. The communication between any two wireless nodes of wireless sensor networks is carried out through a protocol stack. This protocol stack has been designed by different vendors in various ways. Every custom vendor possesses his own protocol stack and algorithms especially at the MAC layer. But, many applications require modifications in their algorithms at various layers as per their requirements, especially energy efficient protocols at MAC layer that are simulated in Wireless sensor Network Simulators which are not being tested in real time systems because vendors do not allow the programmability of each layer in their protocol stack. This problem can be quoted as Vendor-Interoperability. The solution is to develop the programmable protocol stack where we can design our own application as required. As a part of the task first we tried implementing physical layer and transmission of data using physical layer. This paper describes about the transmission of the total number of bytes of Frame according to the IEEE 802.15.4 standard using Physical Layer.

Self-referenced continuous-variable quantum key distribution protocol

DOE PAGES

Soh, Daniel Beom Soo; Sarovar, Mohan; Brif, Constantin; ...

2015-10-21

We introduce a new continuous-variable quantum key distribution (CV-QKD) protocol, self-referenced CV-QKD, that eliminates the need for transmission of a high-power local oscillator between the communicating parties. In this protocol, each signal pulse is accompanied by a reference pulse (or a pair of twin reference pulses), used to align Alice’s and Bob’s measurement bases. The method of phase estimation and compensation based on the reference pulse measurement can be viewed as a quantum analog of intradyne detection used in classical coherent communication, which extracts the phase information from the modulated signal. We present a proof-of-principle, fiber-based experimental demonstration of themore » protocol and quantify the expected secret key rates by expressing them in terms of experimental parameters. Our analysis of the secret key rate fully takes into account the inherent uncertainty associated with the quantum nature of the reference pulse(s) and quantifies the limit at which the theoretical key rate approaches that of the respective conventional protocol that requires local oscillator transmission. The self-referenced protocol greatly simplifies the hardware required for CV-QKD, especially for potential integrated photonics implementations of transmitters and receivers, with minimum sacrifice of performance. Furthermore, it provides a pathway towards scalable integrated CV-QKD transceivers, a vital step towards large-scale QKD networks.« less

Self-referenced continuous-variable quantum key distribution protocol

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

Soh, Daniel Beom Soo; Sarovar, Mohan; Brif, Constantin

We introduce a new continuous-variable quantum key distribution (CV-QKD) protocol, self-referenced CV-QKD, that eliminates the need for transmission of a high-power local oscillator between the communicating parties. In this protocol, each signal pulse is accompanied by a reference pulse (or a pair of twin reference pulses), used to align Alice’s and Bob’s measurement bases. The method of phase estimation and compensation based on the reference pulse measurement can be viewed as a quantum analog of intradyne detection used in classical coherent communication, which extracts the phase information from the modulated signal. We present a proof-of-principle, fiber-based experimental demonstration of themore » protocol and quantify the expected secret key rates by expressing them in terms of experimental parameters. Our analysis of the secret key rate fully takes into account the inherent uncertainty associated with the quantum nature of the reference pulse(s) and quantifies the limit at which the theoretical key rate approaches that of the respective conventional protocol that requires local oscillator transmission. The self-referenced protocol greatly simplifies the hardware required for CV-QKD, especially for potential integrated photonics implementations of transmitters and receivers, with minimum sacrifice of performance. Furthermore, it provides a pathway towards scalable integrated CV-QKD transceivers, a vital step towards large-scale QKD networks.« less

Self-Referenced Continuous-Variable Quantum Key Distribution Protocol

NASA Astrophysics Data System (ADS)

Soh, Daniel B. S.; Brif, Constantin; Coles, Patrick J.; Lütkenhaus, Norbert; Camacho, Ryan M.; Urayama, Junji; Sarovar, Mohan

2015-10-01

We introduce a new continuous-variable quantum key distribution (CV-QKD) protocol, self-referenced CV-QKD, that eliminates the need for transmission of a high-power local oscillator between the communicating parties. In this protocol, each signal pulse is accompanied by a reference pulse (or a pair of twin reference pulses), used to align Alice's and Bob's measurement bases. The method of phase estimation and compensation based on the reference pulse measurement can be viewed as a quantum analog of intradyne detection used in classical coherent communication, which extracts the phase information from the modulated signal. We present a proof-of-principle, fiber-based experimental demonstration of the protocol and quantify the expected secret key rates by expressing them in terms of experimental parameters. Our analysis of the secret key rate fully takes into account the inherent uncertainty associated with the quantum nature of the reference pulse(s) and quantifies the limit at which the theoretical key rate approaches that of the respective conventional protocol that requires local oscillator transmission. The self-referenced protocol greatly simplifies the hardware required for CV-QKD, especially for potential integrated photonics implementations of transmitters and receivers, with minimum sacrifice of performance. As such, it provides a pathway towards scalable integrated CV-QKD transceivers, a vital step towards large-scale QKD networks.

Role of the major antigenic membrane protein in phytoplasma transmission by two insect vector species.

PubMed

Rashidi, Mahnaz; Galetto, Luciana; Bosco, Domenico; Bulgarelli, Andrea; Vallino, Marta; Veratti, Flavio; Marzachì, Cristina

2015-09-30

Phytoplasmas are bacterial plant pathogens (class Mollicutes), transmitted by phloem feeding leafhoppers, planthoppers and psyllids in a persistent/propagative manner. Transmission of phytoplasmas is under the control of behavioral, environmental and geographical factors, but molecular interactions between membrane proteins of phytoplasma and vectors may also be involved. The aim of the work was to provide experimental evidence that in vivo interaction between phytoplasma antigenic membrane protein (Amp) and vector proteins has a role in the transmission process. In doing so, we also investigated the topology of the interaction at the gut epithelium and at the salivary glands, the two barriers encountered by the phytoplasma during vector colonization. Experiments were performed on the 'Candidatus Phytoplasma asteris' chrysanthemum yellows strain (CYP), and the two leafhopper vectors Macrosteles quadripunctulatus Kirschbaum and Euscelidius variegatus Kirschbaum. To specifically address the interaction of CYP Amp at the gut epithelium barrier, insects were artificially fed with media containing either the recombinant phytoplasma protein Amp, or the antibody (A416) or both, and transmission, acquisition and inoculation efficiencies were measured. An abdominal microinjection protocol was employed to specifically address the interaction of CYP Amp at the salivary gland barrier. Phytoplasma suspension was added with Amp or A416 or both, injected into healthy E. variegatus adults and then infection and inoculation efficiencies were measured. An internalization assay was developed, consisting of dissected salivary glands from healthy E. variegatus exposed to phytoplasma suspension alone or together with A416 antibody. The organs were then either observed in confocal microscopy or subjected to DNA extraction and phytoplasma quantification by qPCR, to visualize and quantify possible differences among treatments in localization/presence/number of CYP cells. Artificial feeding and abdominal microinjection protocols were developed to address the two barriers separately. The in vivo interactions between Amp of 'Candidatus Phytoplasma asteris' Chrysanthemum yellows strain (CYP) and vector proteins were studied by evaluating their effects on phytoplasma transmission by Euscelidius variegatus and Macrosteles quadripunctulatus leafhoppers. An internalization assay was developed, consisting of dissected salivary glands from healthy E. variegatus exposed to phytoplasma suspension alone or together with anti-Amp antibody. To visualize possible differences among treatments in localization/presence of CYP cells, the organs were observed in confocal microscopy. Pre-feeding of E. variegatus and M. quadripunctulatus on anti-Amp antibody resulted in a significant decrease of acquisition efficiencies in both species. Inoculation efficiency of microinjected E. variegatus with CYP suspension and anti-Amp antibody was significantly reduced compared to that of the control with phytoplasma suspension only. The possibility that this was due to reduced infection efficiency or antibody-mediated inhibition of phytoplasma multiplication was ruled out. These results provided the first indirect proof of the role of Amp in the transmission process. Protocols were developed to assess the in vivo role of the phytoplasma native major antigenic membrane protein in two phases of the vector transmission process: movement through the midgut epithelium and colonization of the salivary glands. These methods will be useful also to characterize other phytoplasma-vector combinations. Results indicated for the first time that native CYP Amp is involved in vivo in specific crossing of the gut epithelium and salivary gland colonization during early phases of vector infection.

The Achilles' heel of prevention to mother-to-child transmission of HIV: Protocol implementation, uptake, and sustainability.

PubMed

Rodriguez, Violeta J; LaCabe, Richard P; Privette, C Kyle; Douglass, K Marie; Peltzer, Karl; Matseke, Gladys; Mathebula, Audrey; Ramlagan, Shandir; Sifunda, Sibusiso; Prado, Guillermo Willy; Horigian, Viviana; Weiss, Stephen M; Jones, Deborah L

2017-12-01

The Joint United Nations Programme on HIV and AIDS proposed to reduce the vertical transmission of HIV from ∼72,200 to ∼8300 newly infected children by 2015 in South Africa (SA). However, cultural, infrastructural, and socio-economic barriers hinder the implementation of the prevention of mother-to-child transmission (PMTCT) protocol, and research on potential solutions to address these barriers in rural areas is particularly limited. This study sought to identify challenges and solutions to the implementation, uptake, and sustainability of the PMTCT protocol in rural SA. Forty-eight qualitative interviews, 12 focus groups discussions (n = 75), and one two-day workshop (n = 32 participants) were conducted with district directors, clinic leaders, staff, and patients from 12 rural clinics. The delivery and uptake of the PMTCT protocol was evaluated using the Consolidated Framework for Implementation Research (CFIR); 15 themes associated with challenges and solutions emerged. Intervention characteristics themes included PMTCT training and HIV serostatus disclosure. Outer-setting themes included facility space, health record management, and staff shortage; inner-setting themes included supply use and availability, staff-patient relationship, and transportation and scheduling. Themes related to characteristics of individuals included staff relationships, initial antenatal care visit, adherence, and culture and stigma. Implementation process themes included patient education, test results delivery, and male involvement. Significant gaps in care were identified in rural areas. Information obtained from participants using the CFIR framework provided valuable insights into solutions to barriers to PMTCT implementation. Continuously assessing and correcting PMTCT protocol implementation, uptake and sustainability appear merited to maximize HIV prevention.

The Achilles’ heel of prevention to mother-to-child transmission of HIV: Protocol implementation, uptake, and sustainability

PubMed Central

Rodriguez, Violeta J.; LaCabe, Richard P.; Privette, C. Kyle; Douglass, K. Marie; Peltzer, Karl; Matseke, Gladys; Mathebula, Audrey; Ramlagan, Shandir; Sifunda, Sibusiso; Prado, Guillermo “Willy”; Horigian, Viviana; Weiss, Stephen M.; Jones, Deborah L.

2017-01-01

Abstract The Joint United Nations Programme on HIV and AIDS proposed to reduce the vertical transmission of HIV from ∼72,200 to ∼8300 newly infected children by 2015 in South Africa (SA). However, cultural, infrastructural, and socio-economic barriers hinder the implementation of the prevention of mother-to-child transmission (PMTCT) protocol, and research on potential solutions to address these barriers in rural areas is particularly limited. This study sought to identify challenges and solutions to the implementation, uptake, and sustainability of the PMTCT protocol in rural SA. Forty-eight qualitative interviews, 12 focus groups discussions (n = 75), and one two-day workshop (n = 32 participants) were conducted with district directors, clinic leaders, staff, and patients from 12 rural clinics. The delivery and uptake of the PMTCT protocol was evaluated using the Consolidated Framework for Implementation Research (CFIR); 15 themes associated with challenges and solutions emerged. Intervention characteristics themes included PMTCT training and HIV serostatus disclosure. Outer-setting themes included facility space, health record management, and staff shortage; inner-setting themes included supply use and availability, staff–patient relationship, and transportation and scheduling. Themes related to characteristics of individuals included staff relationships, initial antenatal care visit, adherence, and culture and stigma. Implementation process themes included patient education, test results delivery, and male involvement. Significant gaps in care were identified in rural areas. Information obtained from participants using the CFIR framework provided valuable insights into solutions to barriers to PMTCT implementation. Continuously assessing and correcting PMTCT protocol implementation, uptake and sustainability appear merited to maximize HIV prevention. PMID:28922974

Reactive community-based self-administered treatment against residual malaria transmission: study protocol for a randomized controlled trial.

PubMed

Okebe, Joseph; Ribera, Joan Muela; Balen, Julie; Jaiteh, Fatou; Masunaga, Yoriko; Nwakanma, Davis; Bradley, John; Yeung, Shunmay; Peeters Grietens, Koen; D'Alessandro, Umberto

2018-02-20

Systematic treatment of all individuals living in the same compound of a clinical malaria case may clear asymptomatic infections and possibly reduce malaria transmission, where this is focal. High and sustained coverage is extremely important and requires active community engagement. This study explores a community-based approach to treating malaria case contacts. This is a cluster-randomized trial to determine whether, in low-transmission areas, treating individuals living in the same compound of a clinical malaria case with dihydroartemisinin-piperaquine can reduce parasite carriage and thus residual malaria transmission. Treatment will be administered through the local health system with the approach of encouraging community participation designed and monitored through formative research. The trial goal is to show that this approach can reduce in intervention villages the prevalence of Plasmodium falciparum infection toward the end of the malaria transmission season. Adherence and cooperation of the local communities are critical for the success of mass treatment campaigns aimed at reducing malaria transmission. By exploring community perceptions of the changing trends in malaria burden, existing health systems, and reaction to self-administered treatment, this study will develop and adapt a model for community engagement toward malaria elimination that is cost-effective and fits within the existing health system. Clinical trials.gov, NCT02878200 . Registered on 25 August 2016.

High-pressure freezing for scanning transmission electron tomography analysis of cellular organelles.

PubMed

Walther, Paul; Schmid, Eberhard; Höhn, Katharina

2013-01-01

Using an electron microscope's scanning transmission mode (STEM) for collection of tomographic datasets is advantageous compared to bright field transmission electron microscopic (TEM). For image formation, inelastic scattering does not cause chromatic aberration, since in STEM mode no image forming lenses are used after the beam has passed the sample, in contrast to regular TEM. Therefore, thicker samples can be imaged. It has been experimentally demonstrated that STEM is superior to TEM and energy filtered TEM for tomography of samples as thick as 1 μm. Even when using the best electron microscope, adequate sample preparation is the key for interpretable results. We adapted protocols for high-pressure freezing of cultivated cells from a physiological state. In this chapter, we describe optimized high-pressure freezing and freeze substitution protocols for STEM tomography in order to obtain high membrane contrast.

Primary path reservation using enhanced slot assignment in TDMA for session admission.

PubMed

Koneri Chandrasekaran, Suresh; Savarimuthu, Prakash; Andi Elumalai, Priya; Ayyaswamy, Kathirvel

2015-01-01

Mobile ad hoc networks (MANET) is a self-organized collection of nodes that communicates without any infrastructure. Providing quality of service (QoS) in such networks is a competitive task due to unreliable wireless link, mobility, lack of centralized coordination, and channel contention. The success of many real time applications is purely based on the QoS, which can be achieved by quality aware routing (QAR) and admission control (AC). Recently proposed QoS mechanisms do focus completely on either reservation or admission control but are not better enough. In MANET, high mobility causes frequent path break due to the fact that every time the source node must find the route. In such cases the QoS session is affected. To admit a QoS session, admission control protocols must ensure the bandwidth of the relaying path before transmission starts; reservation of such bandwidth noticeably improves the admission control performance. Many TDMA based reservation mechanisms are proposed but need some improvement over slot reservation procedures. In order to overcome this specific issue, we propose a framework-PRAC (primary path reservation admission control protocol), which achieves improved QoS by making use of backup route combined with resource reservation. A network topology has been simulated and our approach proves to be a mechanism that admits the session effectively.

78 FR 14654 - Standards for Business Practices and Communication Protocols for Public Utilities

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-07

... also require each regional transmission organization (RTO) and independent system operator (ISO) to... 20426, (202) 502-6404. Mindi Sauter (legal issues), Office of the General Counsel, Federal Energy... require each regional transmission organization (RTO) and independent system operator (ISO) to address in...

Probable nosocomial transmission of listeriosis in neonates.

PubMed

Lazarus, C; Leclercq, A; Lecuit, M; Vaillant, V; Coignard, B; Blanchard, H; Novakova, I; Astagneau, P

2013-10-01

Listeria monocytogenes was isolated in two neonates born consecutively in the same hospital in France. The isolates had indistinguishable pulsed-field electrophoresis profiles. Retrospective epidemiological investigations found no evidence of a food-borne or environmental source. Infection control protocols and decontamination processes were in accordance with standard recommendations. The timing of onset of these infections within the same maternity unit, and the similarity of pulsed-field gel electrophoresis profiles suggests cross-infection of L. monocytogenes between the two neonates. Copyright © 2013 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

Measurement and Control System Based on Wireless Senor Network for Granary

NASA Astrophysics Data System (ADS)

Song, Jian

A wireless measurement and control system for granary is developed for the sake of overcoming the shortcoming of the wired measurement and control system such as complex wiring and low anti-interference capacity. In this system, Zigbee technology is applied with Zigbee protocol stack development platform by TI, and wireless senor network is used to collect and control the temperature and the humidity. It is composed of the upper PC, central control node based on CC2530, sensor nodes, sensor modules and the executive device. The wireless sensor node is programmed by C language in IAR Embedded Workbench for MCS-51 Evaluation environment. The upper PC control system software is developed based on Visual C++ 6.0 platform. It is shown by experiments that data transmission in the system is accurate and reliable and the error of the temperature and humidity is below 2%, meeting the functional requirements for the granary measurement and control system.

High-Performance CCSDS AOS Protocol Implementation in FPGA

NASA Technical Reports Server (NTRS)

Clare, Loren P.; Torgerson, Jordan L.; Pang, Jackson

2010-01-01

The Consultative Committee for Space Data Systems (CCSDS) Advanced Orbiting Systems (AOS) space data link protocol provides a framing layer between channel coding such as LDPC (low-density parity-check) and higher-layer link multiplexing protocols such as CCSDS Encapsulation Service, which is described in the following article. Recent advancement in RF modem technology has allowed multi-megabit transmission over space links. With this increase in data rate, the CCSDS AOS protocol implementation needs to be optimized to both reduce energy consumption and operate at a high rate.

Evaluation for Loss of Lubrication Performance of Black Oxide, Superfinished, and As-Ground Surfaces for Use in Rotorcraft Transmissions

DTIC Science & Technology

2016-09-01

2.3.2 Loss -of-Lubrication Protocol 5 2.3.3 Friction Mapping Protocol 7 2.4 Test Matrices 9 3. Results and Discussion 10 3.1 Load Capacity 10...protocols used to simulate relevant contact conditions are the load capacity (LC), loss -of-lubrication (LoL), and mapping protocols. 2.3.1 Load ...Entrainment velocity (m/s) Slip (%) Skew (°) Load (N) Contact stress (GPa) LoL 16 –100 0 100 1.29 2.3.2.2 Low-Speed Loss -of-Lubrication

Robust Routing Protocol For Digital Messages

NASA Technical Reports Server (NTRS)

Marvit, Maclen

1994-01-01

Refinement of ditigal-message-routing protocol increases fault tolerance of polled networks. AbNET-3 is latest of generic AbNET protocols for transmission of messages among computing nodes. AbNET concept described in "Multiple-Ring Digital Communication Network" (NPO-18133). Specifically aimed at increasing fault tolerance of network in broadcast mode, in which one node broadcasts message to and receives responses from all other nodes. Communication in network of computers maintained even when links fail.

Improvement of two-way continuous-variable quantum key distribution with virtual photon subtraction

NASA Astrophysics Data System (ADS)

Zhao, Yijia; Zhang, Yichen; Li, Zhengyu; Yu, Song; Guo, Hong

2017-08-01

We propose a method to improve the performance of two-way continuous-variable quantum key distribution protocol by virtual photon subtraction. The virtual photon subtraction implemented via non-Gaussian post-selection not only enhances the entanglement of two-mode squeezed vacuum state but also has advantages in simplifying physical operation and promoting efficiency. In two-way protocol, virtual photon subtraction could be applied on two sources independently. Numerical simulations show that the optimal performance of renovated two-way protocol is obtained with photon subtraction only used by Alice. The transmission distance and tolerable excess noise are improved by using the virtual photon subtraction with appropriate parameters. Moreover, the tolerable excess noise maintains a high value with the increase in distance so that the robustness of two-way continuous-variable quantum key distribution system is significantly improved, especially at long transmission distance.

Web Transfer Over Satellites Being Improved

NASA Technical Reports Server (NTRS)

Allman, Mark

1999-01-01

Extensive research conducted by NASA Lewis Research Center's Satellite Networks and Architectures Branch and the Ohio University has demonstrated performance improvements in World Wide Web transfers over satellite-based networks. The use of a new version of the Hypertext Transfer Protocol (HTTP) reduced the time required to load web pages over a single Transmission Control Protocol (TCP) connection traversing a satellite channel. However, an older technique of simultaneously making multiple requests of a given server has been shown to provide even faster transfer time. Unfortunately, the use of multiple simultaneous requests has been shown to be harmful to the network in general. Therefore, we are developing new mechanisms for the HTTP protocol which may allow a single request at any given time to perform as well as, or better than, multiple simultaneous requests. In the course of study, we also demonstrated that the time for web pages to load is at least as short via a satellite link as it is via a standard 28.8-kbps dialup modem channel. This demonstrates that satellites are a viable means of accessing the Internet.

Low Duty-Cycling MAC Protocol for Low Data-Rate Medical Wireless Body Area Networks

PubMed Central

Zhang, Chongqing; Wang, Yinglong; Liang, Yongquan; Shu, Minglei; Zhang, Jinquan; Ni, Lina

2017-01-01

Wireless body area networks (WBANs) are severely energy constrained, and how to improve the energy efficiency so as to prolong the network lifetime as long as possible is one of the most important goals of WBAN research. Low data-rate WBANs are promising to cut down the energy consumption and extend the network lifetime. Considering the characteristics and demands of low data-rate WBANs, a low duty-cycling medium access control (MAC) protocol is specially designed for this kind of WBAN in this paper. Longer superframes are exploited to cut down the energy consumed on the transmissions and receptions of redundant beacon frames. Insertion time slots are embedded into the inactive part of a superframe to deliver the frames and satisfy the quality of service (QoS) requirements. The number of the data subsections in an insertion time slot can be adaptively adjusted so as to accommodate low data-rate WBANs with different traffic. Simulation results show that the proposed MAC protocol performs well under the condition of low data-rate monitoring traffic. PMID:28509849

New protocol for synthesis of new nanomaterials with continuous 3D networks

NASA Astrophysics Data System (ADS)

Wang, Haiwang; Zhu, Ying; Wei, Xinfang; Chen, Huanhuan; Wang, Ruijie; Zhang, Dong; Song, Huaihe; Song, Shengju

2014-05-01

Nanostructured materials are attractive to researchers because of their unique optical, magnetic, thermodynamic, electrical, mechanical, and chemical properties. Controlling the morphology of nanomaterials could provide structural systems for a wide range of technologies. As a result, the development of nanofabrication techniques that are convenient and offer design flexibility is the subject of many studies. In order to progress beyond the conventional morphologies, we have turned to hydrogels, which can serve as organic templates for nanoscale objects with continuous microstructures. Transmission electron microscopy showed that the obtained nanonetwork had a continuous microstructure, which was several microns in length and width, with a cross-sectional diameter of 5-10 nm synthesized from a 35-g hexamethylenetetramine solution and a 1.5 g Zn(NO3)2 solution, and the cross-sectional diameter can be adjusted from 5 to 200 nm by controlling the concentration of the Zn(NO3)2 solution. Our results also showed that the nanostructures based on a superabsorbent polymer template could be controlled easily in terms of size and morphology by changing the concentration of the reaction solution. This protocol could be easily extended to synthesize a variety of nanostructured materials with novel morphologies.

Counterfactuality of ‘counterfactual’ communication

NASA Astrophysics Data System (ADS)

Vaidman, L.

2015-11-01

The counterfactuality of the recently proposed protocols for direct quantum communication is analyzed. It is argued that the protocols can be counterfactual only for one value of the transmitted bit. The protocols achieve a reduced probability of detection of the particle in the transmission channel by increasing the number of paths in the channel. However, this probability is not lower than the probability of detecting a particle actually passing through such a multi-path channel, which was found to be surprisingly small. The relation between security and counterfactuality of the protocols is discussed. An analysis of counterfactuality of the protocols in the framework of the Bohmian interpretation is performed.

Study protocol for a cluster randomised controlled factorial design trial to assess the effectiveness and feasibility of reactive focal mass drug administration and vector control to reduce malaria transmission in the low endemic setting of Namibia

PubMed Central

Medzihradsky, Oliver F; Kleinschmidt, Immo; Mumbengegwi, Davis; Roberts, Kathryn W; McCreesh, Patrick; Dufour, Mi-Suk Kang; Uusiku, Petrina; Katokele, Stark; Bennett, Adam; Smith, Jennifer; Sturrock, Hugh; Prach, Lisa M; Ntuku, Henry; Tambo, Munyaradzi; Didier, Bradley; Greenhouse, Bryan; Gani, Zaahira; Aerts, Ann; Gosling, Roly; Hsiang, Michelle S

2018-01-01

Introduction To interrupt malaria transmission, strategies must target the parasite reservoir in both humans and mosquitos. Testing of community members linked to an index case, termed reactive case detection (RACD), is commonly implemented in low transmission areas, though its impact may be limited by the sensitivity of current diagnostics. Indoor residual spraying (IRS) before malaria season is a cornerstone of vector control efforts. Despite their implementation in Namibia, a country approaching elimination, these methods have been met with recent plateaus in transmission reduction. This study evaluates the effectiveness and feasibility of two new targeted strategies, reactive focal mass drug administration (rfMDA) and reactive focal vector control (RAVC) in Namibia. Methods and analysis This is an open-label cluster randomised controlled trial with 2×2 factorial design. The interventions include: rfMDA (presumptive treatment with artemether-lumefantrine (AL)) versus RACD (rapid diagnostic testing and treatment using AL) and RAVC (IRS with Acellic 300CS) versus no RAVC. Factorial design also enables comparison of the combined rfMDA+RAVC intervention to RACD. Participants living in 56 enumeration areas will be randomised to one of four arms: rfMDA, rfMDA+RAVC, RACD or RACD+RAVC. These interventions, triggered by index cases detected at health facilities, will be targeted to individuals residing within 500 m of an index. The primary outcome is cumulative incidence of locally acquired malaria detected at health facilities over 1 year. Secondary outcomes include seroprevalence, infection prevalence, intervention coverage, safety, acceptability, adherence, cost and cost-effectiveness. Ethics and dissemination Findings will be reported on clinicaltrials.gov, in peer-reviewed publications and through stakeholder meetings with MoHSS and community leaders in Namibia. Trial registration number NCT02610400; Pre-results. PMID:29374672

Study protocol for a cluster randomised controlled factorial design trial to assess the effectiveness and feasibility of reactive focal mass drug administration and vector control to reduce malaria transmission in the low endemic setting of Namibia.

PubMed

Medzihradsky, Oliver F; Kleinschmidt, Immo; Mumbengegwi, Davis; Roberts, Kathryn W; McCreesh, Patrick; Dufour, Mi-Suk Kang; Uusiku, Petrina; Katokele, Stark; Bennett, Adam; Smith, Jennifer; Sturrock, Hugh; Prach, Lisa M; Ntuku, Henry; Tambo, Munyaradzi; Didier, Bradley; Greenhouse, Bryan; Gani, Zaahira; Aerts, Ann; Gosling, Roly; Hsiang, Michelle S

2018-01-27

To interrupt malaria transmission, strategies must target the parasite reservoir in both humans and mosquitos. Testing of community members linked to an index case, termed reactive case detection (RACD), is commonly implemented in low transmission areas, though its impact may be limited by the sensitivity of current diagnostics. Indoor residual spraying (IRS) before malaria season is a cornerstone of vector control efforts. Despite their implementation in Namibia, a country approaching elimination, these methods have been met with recent plateaus in transmission reduction. This study evaluates the effectiveness and feasibility of two new targeted strategies, reactive focal mass drug administration (rfMDA) and reactive focal vector control (RAVC) in Namibia. This is an open-label cluster randomised controlled trial with 2×2 factorial design. The interventions include: rfMDA (presumptive treatment with artemether-lumefantrine (AL)) versus RACD (rapid diagnostic testing and treatment using AL) and RAVC (IRS with Acellic 300CS) versus no RAVC. Factorial design also enables comparison of the combined rfMDA+RAVC intervention to RACD. Participants living in 56 enumeration areas will be randomised to one of four arms: rfMDA, rfMDA+RAVC, RACD or RACD+RAVC. These interventions, triggered by index cases detected at health facilities, will be targeted to individuals residing within 500 m of an index. The primary outcome is cumulative incidence of locally acquired malaria detected at health facilities over 1 year. Secondary outcomes include seroprevalence, infection prevalence, intervention coverage, safety, acceptability, adherence, cost and cost-effectiveness. Findings will be reported on clinicaltrials.gov, in peer-reviewed publications and through stakeholder meetings with MoHSS and community leaders in Namibia. NCT02610400; Pre-results. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

GLOBECOM '84 - Global Telecommunications Conference, Atlanta, GA, November 26-29, 1984, Conference Record. Volume 3

NASA Astrophysics Data System (ADS)

Attention is given to aspects of quality assurance methodologies in development life cycles, optical intercity transmission systems, multiaccess protocols, system and technology aspects in the case of regional/domestic satellites, advances in SSB-AM radio transmission over terrestrial and satellite network, and development environments for telecommunications systems. Other subjects studied are concerned with business communication networks for voice and data, VLSI in local network and communication protocol, product evaluation and support, an update regarding Videotex, topics in communication theory, topics in radio propagation, a status report regarding societal effects of technology in the workplace, digital image processing, and adaptive signal processing for communications. The management of the reliability function in the development process is considered along with Giga-bit technologies for long distance large capacity optical transmission equipment. The application of gallium arsenide analog and digital integrated circuits for high-speed fiber optical communications, and a simple algorithm for image data coding.

Quantum Authencryption with Two-Photon Entangled States for Off-Line Communicants

NASA Astrophysics Data System (ADS)

Ye, Tian-Yu

2016-02-01

In this paper, a quantum authencryption protocol is proposed by using the two-photon entangled states as the quantum resource. Two communicants Alice and Bob share two private keys in advance, which determine the generation of two-photon entangled states. The sender Alice sends the two-photon entangled state sequence encoded with her classical bits to the receiver Bob in the manner of one-step quantum transmission. Upon receiving the encoded quantum state sequence, Bob decodes out Alice's classical bits with the two-photon joint measurements and authenticates the integrity of Alice's secret with the help of one-way hash function. The proposed protocol only uses the one-step quantum transmission and needs neither a public discussion nor a trusted third party. As a result, the proposed protocol can be adapted to the case where the receiver is off-line, such as the quantum E-mail systems. Moreover, the proposed protocol provides the message authentication to one bit level with the help of one-way hash function and has an information-theoretical efficiency equal to 100 %.

Protocol for communications in potentially noisy environments

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

Boyd, Gerlad M.; Farrow, Jeffrey

2016-02-09

A communications protocol that is designed for transmission of data in networks that are subjected to harsh conditions is described herein. A network includes a plurality of devices, where the devices comprise respective nodes. The nodes are in communication with one another by way of a central network hub. The protocol causes the nodes to transmit data over a network bus at different data rates depending upon whether the nodes are operating normally or an arbitration procedure has been invoked.

A community-engaged infection prevention and control approach to Ebola.

PubMed

Marais, Frederick; Minkler, Meredith; Gibson, Nancy; Mwau, Baraka; Mehtar, Shaheen; Ogunsola, Folasade; Banya, Sama S; Corburn, Jason

2016-06-01

The real missing link in Ebola control efforts to date may lie in the failure to apply core principles of health promotion: the early, active and sustained engagement of affected communities, their trusted leaders, networks and lay knowledge, to help inform what local control teams do, and how they may better do it, in partnership with communities. The predominant focus on viral transmission has inadvertently stigmatized and created fear-driven responses among affected individuals, families and communities. While rigorous adherence to standard infection prevention and control (IPC) precautions and safety standards for Ebola is critical, we may be more successful if we validate and combine local community knowledge and experiences with that of IPC medical teams. In an environment of trust, community partners can help us learn of modest adjustments that would not compromise safety but could improve community understanding of, and responses to, disease control protocol, so that it better reflects their 'community protocol' (local customs, beliefs, knowledge and practices) and concerns. Drawing on the experience of local experts in several African nations and of community-engaged health promotion leaders in the USA, Canada and WHO, we present an eight step model, from entering communities with cultural humility, though reciprocal learning and trust, multi-method communication, development of the joint protocol, to assessing progress and outcomes and building for sustainability. Using examples of changes that are culturally relevant yet maintain safety, we illustrate how often minor adjustments can help prevent and treat the most serious emerging infectious disease since HIV/AIDS. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

FPGA implementation of a ZigBee wireless network control interface to transmit biomedical signals

NASA Astrophysics Data System (ADS)

Gómez López, M. A.; Goy, C. B.; Bolognini, P. C.; Herrera, M. C.

2011-12-01

In recent years, cardiac hemodynamic monitors have incorporated new technologies based on wireless sensor networks which can implement different types of communication protocols. More precisely, a digital conductance catheter system recently developed adds a wireless ZigBee module (IEEE 802.15.4 standards) to transmit cardiac signals (ECG, intraventricular pressure and volume) which would allow the physicians to evaluate the patient's cardiac status in a noninvasively way. The aim of this paper is to describe a control interface, implemented in a FPGA device, to manage a ZigBee wireless network. ZigBee technology is used due to its excellent performance including simplicity, low-power consumption, short-range transmission and low cost. FPGA internal memory stores 8-bit signals with which the control interface prepares the information packets. These data were send to the ZigBee END DEVICE module that receives and transmits wirelessly to the external COORDINATOR module. Using an USB port, the COORDINATOR sends the signals to a personal computer for displaying. Each functional block of control interface was assessed by means of temporal diagrams. Three biological signals, organized in packets and converted to RS232 serial protocol, were sucessfully transmitted and displayed in a PC screen. For this purpose, a custom-made graphical software was designed using LabView.

X-Windows Socket Widget Class

NASA Technical Reports Server (NTRS)

Barry, Matthew R.

2006-01-01

The X-Windows Socket Widget Class ("Class" is used here in the object-oriented-programming sense of the word) was devised to simplify the task of implementing network connections for graphical-user-interface (GUI) computer programs. UNIX Transmission Control Protocol/Internet Protocol (TCP/IP) socket programming libraries require many method calls to configure, operate, and destroy sockets. Most X Windows GUI programs use widget sets or toolkits to facilitate management of complex objects. The widget standards facilitate construction of toolkits and application programs. The X-Windows Socket Widget Class encapsulates UNIX TCP/IP socket-management tasks within the framework of an X Windows widget. Using the widget framework, X Windows GUI programs can treat one or more network socket instances in the same manner as that of other graphical widgets, making it easier to program sockets. Wrapping ISP socket programming libraries inside a widget framework enables a programmer to treat a network interface as though it were a GUI.

Protocol for the use of a rapid real-time PCR method for the detection of HIV-1 proviral DNA using double-stranded primer.

PubMed

Pau, Chou-Pong; Wells, Susan K; Granade, Timothy C

2012-01-01

This chapter describes a real-time PCR method for the detection of HIV-1 proviral DNA in whole blood samples using a novel double-stranded primer system. The assay utilizes a simple commercially available DNA extraction method and a rapid and easy-to-perform real-time PCR protocol to consistently detect a minimum of four copies of HIV-1 group M proviral DNA in as little as 90 min after sample (whole blood) collection. Co-amplification of the human RNase P gene serves as an internal control to monitor the efficiency of both the DNA extraction and amplification. Once the assay is validated properly, it may be suitable as an alternative confirmation test for HIV-1 infections in a variety of HIV testing venues including the mother-to-child transmission testing sites, clinics, and diagnostic testing centers.

ICC '86; Proceedings of the International Conference on Communications, Toronto, Canada, June 22-25, 1986, Conference Record. Volumes 1, 2, & 3

NASA Astrophysics Data System (ADS)

Papers are presented on ISDN, mobile radio systems and techniques for digital connectivity, centralized and distributed algorithms in computer networks, communications networks, quality assurance and impact on cost, adaptive filters in communications, the spread spectrum, signal processing, video communication techniques, and digital satellite services. Topics discussed include performance evaluation issues for integrated protocols, packet network operations, the computer network theory and multiple-access, microwave single sideband systems, switching architectures, fiber optic systems, wireless local communications, modulation, coding, and synchronization, remote switching, software quality, transmission, and expert systems in network operations. Consideration is given to wide area networks, image and speech processing, office communications application protocols, multimedia systems, customer-controlled network operations, digital radio systems, channel modeling and signal processing in digital communications, earth station/on-board modems, computer communications system performance evaluation, source encoding, compression, and quantization, and adaptive communications systems.

Development of risk reduction behavioral counseling for Ebola virus disease survivors enrolled in the Sierra Leone Ebola Virus Persistence Study, 2015-2016.

PubMed

Abad, Neetu; Malik, Tasneem; Ariyarajah, Archchun; Ongpin, Patricia; Hogben, Matthew; McDonald, Suzanna L R; Marrinan, Jaclyn; Massaquoi, Thomas; Thorson, Anna; Ervin, Elizabeth; Bernstein, Kyle; Ross, Christine; Liu, William J; Kroeger, Karen; Durski, Kara N; Broutet, Nathalie; Knust, Barbara; Deen, Gibrilla F

2017-09-01

During the 2014-2016 West Africa Ebola Virus Disease (EVD) epidemic, the public health community had concerns that sexual transmission of the Ebola virus (EBOV) from EVD survivors was a risk, due to EBOV persistence in body fluids of EVD survivors, particularly semen. The Sierra Leone Ebola Virus Persistence Study was initiated to investigate this risk by assessing EBOV persistence in numerous body fluids of EVD survivors and providing risk reduction counseling based on test results for semen, vaginal fluid, menstrual blood, urine, rectal fluid, sweat, tears, saliva, and breast milk. This publication describes implementation of the counseling protocol and the key lessons learned. The Ebola Virus Persistence Risk Reduction Behavioral Counseling Protocol was developed from a framework used to prevent transmission of HIV and other sexually transmitted infections. The framework helped to identify barriers to risk reduction and facilitated the development of a personalized risk-reduction plan, particularly around condom use and abstinence. Pre-test and post-test counseling sessions included risk reduction guidance, and post-test counseling was based on the participants' individual test results. The behavioral counseling protocol enabled study staff to translate the study's body fluid test results into individualized information for study participants. The Ebola Virus Persistence Risk Reduction Behavioral Counseling Protocol provided guidance to mitigate the risk of EBOV transmission from EVD survivors. It has since been shared with and adapted by other EVD survivor body fluid testing programs and studies in Ebola-affected countries.

Nanowire growth kinetics in aberration corrected environmental transmission electron microscopy

DOE PAGES

Chou, Yi -Chia; Panciera, Federico; Reuter, Mark C.; ...

2016-03-15

Here, we visualize atomic level dynamics during Si nanowire growth using aberration corrected environmental transmission electron microscopy, and compare with lower pressure results from ultra-high vacuum microscopy. We discuss the importance of higher pressure observations for understanding growth mechanisms and describe protocols to minimize effects of the higher pressure background gas.

Enhancement of the NMSU Channel Error Simulator to Provide User-Selectable Link Delays

NASA Technical Reports Server (NTRS)

Horan, Stephen; Wang, Ru-Hai

2000-01-01

This is the third in a continuing series of reports describing the development of the Space-to-Ground Link Simulator (SGLS) to be used for testing data transfers under simulated space channel conditions. The SGLS is based upon Virtual Instrument (VI) software techniques for managing the error generation, link data rate configuration, and, now, selection of the link delay value. In this report we detail the changes that needed to be made to the SGLS VI configuration to permit link delays to be added to the basic error generation and link data rate control capabilities. This was accomplished by modifying the rate-splitting VIs to include a buffer the hold the incoming data for the duration selected by the user to emulate the channel link delay. In sample tests of this configuration, the TCP/IP(sub ftp) service and the SCPS(sub fp) service were used to transmit 10-KB data files using both symmetric (both forward and return links set to 115200 bps) and unsymmetric (forward link set at 2400 bps and a return link set at 115200 bps) link configurations. Transmission times were recorded at bit error rates of 0 through 10(exp -5) to give an indication of the link performance. In these tests. we noted separate timings for the protocol setup time to initiate the file transfer and the variation in the actual file transfer time caused by channel errors. Both protocols showed similar performance to that seen earlier for the symmetric and unsymmetric channels. This time, the delays in establishing the file protocol also showed that these delays could double the transmission time and need to be accounted for in mission planning. Both protocols also showed a difficulty in transmitting large data files over large link delays. In these tests, there was no clear favorite between the TCP/IP(sub ftp) and the SCPS(sub fp). Based upon these tests, further testing is recommended to extend the results to different file transfer configurations.

An implementation of a data-transmission pipelining algorithm on Imote2 platforms

NASA Astrophysics Data System (ADS)

Li, Xu; Dorvash, Siavash; Cheng, Liang; Pakzad, Shamim

2011-04-01

Over the past several years, wireless network systems and sensing technologies have been developed significantly. This has resulted in the broad application of wireless sensor networks (WSNs) in many engineering fields and in particular structural health monitoring (SHM). The movement of traditional SHM toward the new generation of SHM, which utilizes WSNs, relies on the advantages of this new approach such as relatively low costs, ease of implementation and the capability of onboard data processing and management. In the particular case of long span bridge monitoring, a WSN should be capable of transmitting commands and measurement data over long network geometry in a reliable manner. While using single-hop data transmission in such geometry requires a long radio range and consequently a high level of power supply, multi-hop communication may offer an effective and reliable way for data transmissions across the network. Using a multi-hop communication protocol, the network relays data from a remote node to the base station via intermediary nodes. We have proposed a data-transmission pipelining algorithm to enable an effective use of the available bandwidth and minimize the energy consumption and the delay performance by the multi-hop communication protocol. This paper focuses on the implementation aspect of the pipelining algorithm on Imote2 platforms for SHM applications, describes its interaction with underlying routing protocols, and presents the solutions to various implementation issues of the proposed pipelining algorithm. Finally, the performance of the algorithm is evaluated based on the results of an experimental implementation.

Energy neutral protocol based on hierarchical routing techniques for energy harvesting wireless sensor network

NASA Astrophysics Data System (ADS)

Muhammad, Umar B.; Ezugwu, Absalom E.; Ofem, Paulinus O.; Rajamäki, Jyri; Aderemi, Adewumi O.

2017-06-01

Recently, researchers in the field of wireless sensor networks have resorted to energy harvesting techniques that allows energy to be harvested from the ambient environment to power sensor nodes. Using such Energy harvesting techniques together with proper routing protocols, an Energy Neutral state can be achieved so that sensor nodes can run perpetually. In this paper, we propose an Energy Neutral LEACH routing protocol which is an extension to the traditional LEACH protocol. The goal of the proposed protocol is to use Gateway node in each cluster so as to reduce the data transmission ranges of cluster head nodes. Simulation results show that the proposed routing protocol achieves a higher throughput and ensure the energy neutral status of the entire network.

Epigenetics and sex-specific fitness: an experimental test using male-limited evolution in Drosophila melanogaster.

PubMed

Abbott, Jessica K; Innocenti, Paolo; Chippindale, Adam K; Morrow, Edward H

2013-01-01

When males and females have different fitness optima for the same trait but share loci, intralocus sexual conflict is likely to occur. Epigenetic mechanisms such as genomic imprinting (in which expression is altered according to parent-of-origin) and sex-specific maternal effects have been suggested as ways by which this conflict can be resolved. However these ideas have not yet been empirically tested. We designed an experimental evolution protocol in Drosophila melanogaster that enabled us to look for epigenetic effects on the X-chromosome-a hotspot for sexually antagonistic loci. We used special compound-X females to enforce father-to-son transmission of the X-chromosome for many generations, and compared fitness and gene expression levels between Control males, males with a Control X-chromosome that had undergone one generation of father-son transmission, and males with an X-chromosome that had undergone many generations of father-son transmission. Fitness differences were dramatic, with experimentally-evolved males approximately 20% greater than controls, and with males inheriting a non-evolved X from their father about 20% lower than controls. These data are consistent with both strong intralocus sexual conflict and misimprinting of the X-chromosome under paternal inheritance. However, expression differences suggested that reduced fitness under paternal X inheritance was largely due to deleterious maternal effects. Our data confirm the sexually-antagonistic nature of Drosophila's X-chromosome and suggest that the response to male-limited X-chromosome evolution entails compensatory evolution for maternal effects, and perhaps modification of other epigenetic effects via coevolution of the sex chromosomes.

Traffic Management for Emergency Vehicle Priority Based on Visual Sensing.

PubMed

Nellore, Kapileswar; Hancke, Gerhard P

2016-11-10

Vehicular traffic is endlessly increasing everywhere in the world and can cause terrible traffic congestion at intersections. Most of the traffic lights today feature a fixed green light sequence, therefore the green light sequence is determined without taking the presence of the emergency vehicles into account. Therefore, emergency vehicles such as ambulances, police cars, fire engines, etc. stuck in a traffic jam and delayed in reaching their destination can lead to loss of property and valuable lives. This paper presents an approach to schedule emergency vehicles in traffic. The approach combines the measurement of the distance between the emergency vehicle and an intersection using visual sensing methods, vehicle counting and time sensitive alert transmission within the sensor network. The distance between the emergency vehicle and the intersection is calculated for comparison using Euclidean distance, Manhattan distance and Canberra distance techniques. The experimental results have shown that the Euclidean distance outperforms other distance measurement techniques. Along with visual sensing techniques to collect emergency vehicle information, it is very important to have a Medium Access Control (MAC) protocol to deliver the emergency vehicle information to the Traffic Management Center (TMC) with less delay. Then only the emergency vehicle is quickly served and can reach the destination in time. In this paper, we have also investigated the MAC layer in WSNs to prioritize the emergency vehicle data and to reduce the transmission delay for emergency messages. We have modified the medium access procedure used in standard IEEE 802.11p with PE-MAC protocol, which is a new back off selection and contention window adjustment scheme to achieve low broadcast delay for emergency messages. A VANET model for the UTMS is developed and simulated in NS-2. The performance of the standard IEEE 802.11p and the proposed PE-MAC is analysed in detail. The NS-2 simulation results have shown that the PE-MAC outperforms the IEEE 802.11p in terms of average end-to-end delay, throughput and energy consumption. The performance evaluation results have proven that the proposed PE-MAC prioritizes the emergency vehicle data and delivers the emergency messages to the TMC with less delay compared to the IEEE 802.11p. The transmission delay of the proposed PE-MAC is also compared with the standard IEEE 802.15.4, and Enhanced Back-off Selection scheme for IEEE 802.15.4 protocol [EBSS, an existing protocol to ensure fast transmission of the detected events on the road towards the TMC] and the comparative results have proven the effectiveness of the PE-MAC over them. Furthermore, this research work will provide an insight into the design of an intelligent urban traffic management system for the effective management of emergency vehicles and will help to save lives and property.

Factors that are associated with the risk of acquiring Plasmodium knowlesi malaria in Sabah, Malaysia: a case-control study protocol

PubMed Central

Grigg, M J; William, T; Drakeley, C J; Jelip, J; von Seidlein, L; Barber, B E; Fornace, K M; Anstey, N M; Yeo, T W; Cox, J

2014-01-01

Introduction Plasmodium knowlesi has long been present in Malaysia, and is now an emerging cause of zoonotic human malaria. Cases have been confirmed throughout South-East Asia where the ranges of its natural macaque hosts and Anopheles leucosphyrus group vectors overlap. The majority of cases are from Eastern Malaysia, with increasing total public health notifications despite a concurrent reduction in Plasmodium falciparum and P. vivax malaria. The public health implications are concerning given P. knowlesi has the highest risk of severe and fatal disease of all Plasmodium spp in Malaysia. Current patterns of risk and disease vary based on vector type and competence, with individual exposure risks related to forest and forest-edge activities still poorly defined. Clustering of cases has not yet been systematically evaluated despite reports of peri-domestic transmission and known vector competence for human-to-human transmission. Methods and analysis A population-based case–control study will be conducted over a 2-year period at two adjacent districts in north-west Sabah, Malaysia. Confirmed malaria cases presenting to the district hospital sites meeting relevant inclusion criteria will be requested to enrol. Three community controls matched to the same village as the case will be selected randomly. Study procedures will include blood sampling and administration of household and individual questionnaires to evaluate potential exposure risks associated with acquisition of P. knowlesi malaria. Secondary outcomes will include differences in exposure variables between P. knowlesi and other Plasmodium spp, risk of severe P. knowlesi malaria, and evaluation of P. knowlesi case clustering. Primary analysis will be per protocol, with adjusted ORs for exposure risks between cases and controls calculated using conditional multiple logistic regression models. Ethics This study has been approved by the human research ethics committees of Malaysia, the Menzies School of Health Research, Australia, and the London School of Hygiene and Tropical Medicine, UK. PMID:25149186

Proposed Development of NASA Glenn Research Center's Aeronautical Network Research Simulator

NASA Technical Reports Server (NTRS)

Nguyen, Thanh C.; Kerczewski, Robert J.; Wargo, Chris A.; Kocin, Michael J.; Garcia, Manuel L.

2004-01-01

Accurate knowledge and understanding of data link traffic loads that will have an impact on the underlying communications infrastructure within the National Airspace System (NAS) is of paramount importance for planning, development and fielding of future airborne and ground-based communications systems. Attempting to better understand this impact, NASA Glenn Research Center (GRC), through its contractor Computer Networks & Software, Inc. (CNS, Inc.), has developed an emulation and test facility known as the Virtual Aircraft and Controller (VAC) to study data link interactions and the capacity of the NAS to support Controller Pilot Data Link Communications (CPDLC) traffic. The drawback of the current VAC test bed is that it does not allow the test personnel and researchers to present a real world RF environment to a complex airborne or ground system. Fortunately, the United States Air Force and Navy Avionics Test Commands, through its contractor ViaSat, Inc., have developed the Joint Communications Simulator (JCS) to provide communications band test and simulation capability for the RF spectrum through 18 GHz including Communications, Navigation, and Identification and Surveillance functions. In this paper, we are proposing the development of a new and robust test bed that will leverage on the existing NASA GRC's VAC and the Air Force and Navy Commands JCS systems capabilities and functionalities. The proposed NASA Glenn Research Center's Aeronautical Networks Research Simulator (ANRS) will combine current Air Traffic Control applications and physical RF stimulation into an integrated system capable of emulating data transmission behaviors including propagation delay, physical protocol delay, transmission failure and channel interference. The ANRS will provide a simulation/stimulation tool and test bed environment that allow the researcher to predict the performance of various aeronautical network protocol standards and their associated waveforms under varying density conditions. The system allows the user to define human-interactive and scripted aircraft and controller models of various standards, such as (but not limited to) Very High Frequency Digital Link (VDL) of various modes.

A reliable user authentication and key agreement scheme for Web-based Hospital-acquired Infection Surveillance Information System.

PubMed

Wu, Zhen-Yu; Tseng, Yi-Ju; Chung, Yufang; Chen, Yee-Chun; Lai, Feipei

2012-08-01

With the rapid development of the Internet, both digitization and electronic orientation are required on various applications in the daily life. For hospital-acquired infection control, a Web-based Hospital-acquired Infection Surveillance System was implemented. Clinical data from different hospitals and systems were collected and analyzed. The hospital-acquired infection screening rules in this system utilized this information to detect different patterns of defined hospital-acquired infection. Moreover, these data were integrated into the user interface of a signal entry point to assist physicians and healthcare providers in making decisions. Based on Service-Oriented Architecture, web-service techniques which were suitable for integrating heterogeneous platforms, protocols, and applications, were used. In summary, this system simplifies the workflow of hospital infection control and improves the healthcare quality. However, it is probable for attackers to intercept the process of data transmission or access to the user interface. To tackle the illegal access and to prevent the information from being stolen during transmission over the insecure Internet, a password-based user authentication scheme is proposed for information integrity.

Zika Virus: A Review of Management Considerations and Controversies at Six Months.

PubMed

Singer, Laura; Vest, Kelly G; Beadling, Charles W

2017-06-01

Zika virus continues to pose a significant global health threat. While the outbreak pattern may seemingly mirror those of other arboviruses, unique transmission characteristics and clinical outcomes warrant a different approach to traditional public health practices. Sexual transmission and virus-associated fetal and nonfetal neurologic disorders specifically challenge conventional methods of disease protection and prevention with regard to vector control, disease surveillance, and health risk communication. The protocols for outbreak and case limitation led by the World Health Organization (in accordance with Public Health Emergency of International Concern declaration) may be augmented by localized risk categorization and assignment for Zika and future emergent outbreaks. There is currently a great deal of "behind the scenes" discussion about modifications to the formal process described in the International Health Regulations. A scalable, adaptable, and flexible process is needed that can be customized to a specific threat. (Disaster Med Public Health Preparedness. 2017;11:279-284).

Performance analysis of multi-radio routing protocol in cognitive radio ad hoc networks under different path failure rate

NASA Astrophysics Data System (ADS)

Che-Aron, Z.; Abdalla, A. H.; Abdullah, K.; Hassan, W. H.

2013-12-01

In recent years, Cognitive Radio (CR) technology has largely attracted significant studies and research. Cognitive Radio Ad Hoc Network (CRAHN) is an emerging self-organized, multi-hop, wireless network which allows unlicensed users to opportunistically access available licensed spectrum bands for data communication under an intelligent and cautious manner. However, in CRAHNs, a lot of failures can easily occur during data transmission caused by PU (Primary User) activity, topology change, node fault, or link degradation. In this paper, an attempt has been made to evaluate the performance of the Multi-Radio Link-Quality Source Routing (MR-LQSR) protocol in CRAHNs under different path failure rate. In the MR-LQSR protocol, the Weighted Cumulative Expected Transmission Time (WCETT) is used as the routing metric. The simulations are carried out using the NS-2 simulator. The protocol performance is evaluated with respect to performance metrics like average throughput, packet loss, average end-to-end delay and average jitter. From the simulation results, it is observed that the number of path failures depends on the PUs number and mobility rate of SUs (Secondary Users). Moreover, the protocol performance is greatly affected when the path failure rate is high, leading to major service outages.

A QoS-guaranteed coverage precedence routing algorithm for wireless sensor networks.

PubMed

Jiang, Joe-Air; Lin, Tzu-Shiang; Chuang, Cheng-Long; Chen, Chia-Pang; Sun, Chin-Hong; Juang, Jehn-Yih; Lin, Jiun-Chuan; Liang, Wei-Wen

2011-01-01

For mission-critical applications of wireless sensor networks (WSNs) involving extensive battlefield surveillance, medical healthcare, etc., it is crucial to have low-power, new protocols, methodologies and structures for transferring data and information in a network with full sensing coverage capability for an extended working period. The upmost mission is to ensure that the network is fully functional providing reliable transmission of the sensed data without the risk of data loss. WSNs have been applied to various types of mission-critical applications. Coverage preservation is one of the most essential functions to guarantee quality of service (QoS) in WSNs. However, a tradeoff exists between sensing coverage and network lifetime due to the limited energy supplies of sensor nodes. In this study, we propose a routing protocol to accommodate both energy-balance and coverage-preservation for sensor nodes in WSNs. The energy consumption for radio transmissions and the residual energy over the network are taken into account when the proposed protocol determines an energy-efficient route for a packet. The simulation results demonstrate that the proposed protocol is able to increase the duration of the on-duty network and provide up to 98.3% and 85.7% of extra service time with 100% sensing coverage ratio comparing with LEACH and the LEACH-Coverage-U protocols, respectively.

Rural emergency medical technician pre-hospital electrocardiogram transmission.

PubMed

Powell, A M; Halon, J M; Nelson, J

2014-01-01

Emergent care of the acute heart attack patient continues to be at the forefront of quality and cost reduction strategies throughout the healthcare industry. Although the average cardiac door-to-balloon (D2B) times have decreased substantially over the past few years, there are still vast disparities found in D2B times in populations that reside in rural areas. Such disparities are mostly related to prolonged travel time and subsequent delays in cardiac catherization lab team activation. Urban ambulance companies that are routinely staffed with paramedic level providers have been successful in the implementation of pre-hospital 12-lead electrocardiogram (ECG) protocols as a strategy to reduce D2B times. The authors sought to evaluate the evidence related to the risk and benefits associated with the replication of an ECG transmission protocol in a small rural emergency medical service. The latter is staffed with emergency medical technician-basics (EMT-B), emergency medical technician-advanced (EMT-A), and emergency medical technician-intermediate (EMT-I) level. The evidence reviewed was limited to studies with relevant data regarding the challenges and complexities of the ECG transmission process, the difficulties associated with ECG transmission in rural settings, and ECG transmission outcomes by provider level. The evidence supports additional research to further evaluate the feasibility of ECG transmission at the non-paramedic level. Multiple variables must be investigated including equipment cost, utilization, and rural transmission capabilities. Clearly, pre-hospital ECG transmission and early activation of the cardiac catheterization laboratory are critical components to successfully decreasing D2B times.

Control Strategies for Endemic Childhood Scabies

PubMed Central

Gilmore, Stephen J.

2011-01-01

Human scabies is a major global public health issue, with an estimated 300 million cases per year worldwide. Prevalence rates are particularly high in many third-world regions and within various indigenous communities in developed countries. Infestation with Sarcoptes Scabiei is associated with group-A streptococcal pyoderma which in turn predisposes to rheumatic fever, acute glomerulonephritis and their respective long-term sequelae: rheumatic heart disease and chronic renal insufficiency. The documented difficulties inherent in achieving scabies control within affected communities have motivated us to develop a network-dependent Monte-Carlo model of the scabies contagion, with the dual aims of gaining insight into its dynamics, and in determining the effects of various treatment strategies. Here we show that scabies burden is adversely affected by increases in average network degree, prominent network clustering, and by a person-to-person transmissibility of greater magnitude. We demonstrate that creating a community-specific model allows for the determination of an effective treatment protocol that can satisfy any pre-defined target prevalence. We find frequent low-density treatment protocols are inherently advantageous in comparison with infrequent mass screening and treatment regimes: prevalence rates are lower when compared with protocols that administer the same number of treatments over a given time interval less frequently, and frequent low-density treatment protocols have economic, practical and public acceptance advantages that may facilitate their long-term implementation. This work demonstrates the importance of stochasticity, community structure and the heterogeneity of individuals in influencing the dynamics of the human scabies contagion, and provides a practical method for investigating the outcomes of various intervention strategies. PMID:21283575

On Alarm Protocol in Wireless Sensor Networks

NASA Astrophysics Data System (ADS)

Cichoń, Jacek; Kapelko, Rafał; Lemiesz, Jakub; Zawada, Marcin

We consider the problem of efficient alarm protocol for ad-hoc radio networks consisting of devices that try to gain access for transmission through a shared radio communication channel. The problem arise in tasks that sensors have to quickly inform the target user about an alert situation such as presence of fire, dangerous radiation, seismic vibrations, and more. In this paper, we present a protocol which uses O(logn) time slots and show that Ω(logn/loglogn) is a lower bound for used time slots.

Research in DRM architecture based on watermarking and PKI

NASA Astrophysics Data System (ADS)

Liu, Ligang; Chen, Xiaosu; Xiao, Dao-ju; Yi, Miao

2005-02-01

Analyze the virtue and disadvantage of the present digital copyright protecting system, design a kind of security protocol model of digital copyright protection, which equilibrium consider the digital media"s use validity, integrality, security of transmission, and trade equity, make a detailed formalize description to the protocol model, analyze the relationship of the entities involved in the digital work copyright protection. The analysis of the security and capability of the protocol model shows that the model is good at security and practicability.

Data dissemination using gossiping in wireless sensor networks

NASA Astrophysics Data System (ADS)

Medidi, Muralidhar; Ding, Jin; Medidi, Sirisha

2005-06-01

Disseminating data among sensors is a fundamental operation in energy-constrained wireless sensor networks. We present a gossip-based adaptive protocol for data dissemination to improve energy efficiency of this operation. To overcome the data implosion problems associated with dissemination operation, our protocol uses meta-data to name the data using high-level data descriptors and negotiation to eliminate redundant transmissions of duplicate data in the network. Further, we adapt the gossiping with data aggregation possibilities in sensor networks. We simulated our data dissemination protocol, and compared it to the SPIN protocol. We find that our protocol improves on the energy consumption by about 20% over others, while improving significantly over the data dissemination rate of gossiping.

Fundamental Lifetime Mechanisms in Routing Protocols for Wireless Sensor Networks: A Survey and Open Issues

PubMed Central

Eslaminejad, Mohammadreza; Razak, Shukor Abd

2012-01-01

Wireless sensor networks basically consist of low cost sensor nodes which collect data from environment and relay them to a sink, where they will be subsequently processed. Since wireless nodes are severely power-constrained, the major concern is how to conserve the nodes' energy so that network lifetime can be extended significantly. Employing one static sink can rapidly exhaust the energy of sink neighbors. Furthermore, using a non-optimal single path together with a maximum transmission power level may quickly deplete the energy of individual nodes on the route. This all results in unbalanced energy consumption through the sensor field, and hence a negative effect on the network lifetime. In this paper, we present a comprehensive taxonomy of the various mechanisms applied for increasing the network lifetime. These techniques, whether in the routing or cross-layer area, fall within the following types: multi-sink, mobile sink, multi-path, power control and bio-inspired algorithms, depending on the protocol operation. In this taxonomy, special attention has been devoted to the multi-sink, power control and bio-inspired algorithms, which have not yet received much consideration in the literature. Moreover, each class covers a variety of the state-of-the-art protocols, which should provide ideas for potential future works. Finally, we compare these mechanisms and discuss open research issues. PMID:23202008

Fundamental lifetime mechanisms in routing protocols for wireless sensor networks: a survey and open issues.

PubMed

Eslaminejad, Mohammadreza; Razak, Shukor Abd

2012-10-09

Wireless sensor networks basically consist of low cost sensor nodes which collect data from environment and relay them to a sink, where they will be subsequently processed. Since wireless nodes are severely power-constrained, the major concern is how to conserve the nodes' energy so that network lifetime can be extended significantly. Employing one static sink can rapidly exhaust the energy of sink neighbors. Furthermore, using a non-optimal single path together with a maximum transmission power level may quickly deplete the energy of individual nodes on the route. This all results in unbalanced energy consumption through the sensor field, and hence a negative effect on the network lifetime. In this paper, we present a comprehensive taxonomy of the various mechanisms applied for increasing the network lifetime. These techniques, whether in the routing or cross-layer area, fall within the following types: multi-sink, mobile sink, multi-path, power control and bio-inspired algorithms, depending on the protocol operation. In this taxonomy, special attention has been devoted to the multi-sink, power control and bio-inspired algorithms, which have not yet received much consideration in the literature. Moreover, each class covers a variety of the state-of-the-art protocols, which should provide ideas for potential future works. Finally, we compare these mechanisms and discuss open research issues.

In situ thermal polymerisation of natural oils as novel sustainable approach in nanographite particle production

NASA Astrophysics Data System (ADS)

Datsyuk, Vitaliy; Trotsenko, Svitlana; Reich, Stephanie

2018-01-01

A sustainable approach to graphite exfoliation via in situ thermal polymerization of fish oil results in the production of nanographite particles. The material was characterized by elemental analysis, transmission electron microscopy, and Raman spectroscopy. The thermal polymerization of fish oil was controlled by monitoring the viscosity and measuring the iodine number. The number of structural defects on the graphitic surface remained constant during the synthesis. The protocol leads to a hydrophobization of the nanographite surface. Immobilized polyoil islands create sterical hindrance and stabilize the nanographite particles in engineering polymers.

Evaluation of Swift Start TCP in Long-Delay Environment

NASA Technical Reports Server (NTRS)

Lawas-Grodek, Frances J.; Tran, Diepchi T.

2004-01-01

This report presents the test results of the Swift Start algorithm in single-flow and multiple-flow testbeds under the effects of high propagation delays, various slow bottlenecks, and small queue sizes. Although this algorithm estimates capacity and implements packet pacing, the findings were that in a heavily congested link, the Swift Start algorithm will not be applicable. The reason is that the bottleneck estimation is falsely influenced by timeouts induced by retransmissions and the expiration of delayed acknowledgment (ACK) timers, thus causing the modified Swift Start code to fall back to regular transmission control protocol (TCP).

Learning and memory in disease vector insects

PubMed Central

Vinauger, Clément; Lahondère, Chloé; Cohuet, Anna; Lazzari, Claudio R.; Riffell, Jeffrey A.

2016-01-01

Learning and memory plays an important role in host preference and parasite transmission by disease vector insects. Historically there has been a dearth of standardized protocols that permit testing their learning abilities, thus limiting discussion on the potential epidemiological consequences of learning and memory to a largely speculative extent. However, with increasing evidence that individual experience and associative learning can affect processes such as oviposition site selection and host preference, it is timely to review the recently acquired knowledge, identify research gaps and discuss the implication of learning in disease vector insects in perspective with control strategies. PMID:27450224

#FoundThem-21st Century pre-search and post-detection seti protocols for social and digital media

NASA Astrophysics Data System (ADS)

Forgan, Duncan; Scholz, Alexander

2016-09-01

The transmission of news stories in global culture has changed fundamentally in the last three decades. The general public are alerted to breaking stories on increasingly rapid timescales, and the discussion/distortion of facts by writers, bloggers, commenters and Internet users can also be extremely fast. The narrative of a news item no longer belongs to a small cadre of conventional media outlets, but is instead synthesised to some level by the public as they select where and how they consume news. The IAA Search for Extraterrestrial Intelligence (SETI) post-detection protocols, initially drafted in 1989 and updated in 2010, were written to guide SETI scientists in the event of detecting evidence of extraterrestrial intelligence, but do not give guidance as to how scientists should prepare to navigate this media maelstrom. The protocols assume communication channels between scientists and the public still resemble those of 1989, which were specifically one-way with a narrative controlled by a select few media outlets. Modern SETI researchers must consider this modern paradigm for consumption of news by the public, using social media and other non-traditional outlets, when planning and executing searches for extraterrestrial intelligence. We propose additions to the post detection protocols as they pertain to the use of the Internet and social media, as well as pre-search protocols. It is our belief that such protocols are necessary if there is to be a well-informed, sane global conversation amongst the world's citizens following the discovery of intelligent life beyond the Earth.

Integrated-optics heralded controlled-NOT gate for polarization-encoded qubits

NASA Astrophysics Data System (ADS)

Zeuner, Jonas; Sharma, Aditya N.; Tillmann, Max; Heilmann, René; Gräfe, Markus; Moqanaki, Amir; Szameit, Alexander; Walther, Philip

2018-03-01

Recent progress in integrated-optics technology has made photonics a promising platform for quantum networks and quantum computation protocols. Integrated optical circuits are characterized by small device footprints and unrivalled intrinsic interferometric stability. Here, we take advantage of femtosecond-laser-written waveguides' ability to process polarization-encoded qubits and present an implementation of a heralded controlled-NOT gate on chip. We evaluate the gate performance in the computational basis and a superposition basis, showing that the gate can create polarization entanglement between two photons. Transmission through the integrated device is optimized using thermally expanded core fibers and adiabatically reduced mode-field diameters at the waveguide facets. This demonstration underlines the feasibility of integrated quantum gates for all-optical quantum networks and quantum repeaters.

Traffic flow collection wireless sensor network node for intersection light control

NASA Astrophysics Data System (ADS)

Li, Xu; Li, Xue

2011-10-01

Wireless sensor network (WSN) is expected to be deployed in intersection to monitor the traffic flow continuously, and the monitoring datum can be used as the foundation of traffic light control. In this paper, a WSN based on ZigBee protocol for monitoring traffic flow is proposed. Structure, hardware and work flow of WSN nodes are designed. CC2431 from Texas Instrument is chosen as the main computational and transmission unit, and CC2591 as the amplification unit. The stability experiment and the actual environment experiment are carried out in the last of the paper. The results of experiments show that WSN has the ability to collect traffic flow information quickly and transmit the datum to the processing center in real time.

Protocol and Topology Issues for Wide-Area Satellite Interconnection of Terrestrial Optical LANs

NASA Astrophysics Data System (ADS)

Parraga, N.

2002-01-01

Apart from broadcasting, the satellite business is targeting niche markets. Wide area interconnection is considered as one of these niche markets, since it addresses operators and business LANs (B2B, business to business) in remote areas where terrestrial infrastructure is not available. These LANs - if high-speed - are typically based on optical networks such as SONET. One of the advantages of SONET is its architecture flexibility and capacity to transport all kind of applications including multimedia with a range of different transmission rates. The applications can be carried by different protocols among which the Internet Protocol (IP) or the Asynchronous Transfer Mode (ATM) are the most prominent ones. Thus, the question arises how these protocols can be interconnected via the satellite segment. The paper addresses several solutions for interworking with different protocols. For this investigation we distinguish first of all between the topology and the switching technology of the satellites. In case of a star network with transparent satellite, the satellite protocol consists of physical layer and data layer which can be directly interconnected with layer 2 interworking function to their terrestrial counterparts in the SONET backbone. For regenerative satellites the situation is more complex: here we need to distinguish the types of transport protocols being used in the terrestrial and satellite segment. Whereas IP, ATM, MPEG dominate in the terrestrial networks, satellite systems usually do not follow these standards. Some might employ minor additions (for instance, satellite specific packet headers), some might be completely proprietary. In general, interworking must be done for the data plane on top of layer 2 (data link layer), whereas for the signaling plane the interworking is on top of layer 3. In the paper we will discuss the protocol stacks for ATM, IP, and MPEG with a regenerative satellite system. As an example we will use the EuroSkyWay satellite system for multimedia services. EuroSkyWay uses a GEO satellite with onboard switching. It has its own proprietary protocol stack for data link control (DLC), logical link control (LLC) and layer 3 functions such as resource management, call admission control and authentication. Special attention is paid to the IP interworking with Layer 3 function since IP does not support connection set-up and session protocols, thus proper interworking functions with IP signaling protocols for resource reservation routing such as RSVP, BGP, and ICMP need to be developed. Whereas the EuroSkyWay system is an representative for a meshed topology, DVB-RCS systems have usually star configuration with a central hub station. Different data streams are distinguished by program identifiers (PIDs). Recent proposals aim at the evolution of DVB-RCS towards a fully meshed structure. The paper will also discuss the protocol architecture for interconnect SONET LANs over these systems. Finally, a performance comparison of the different solutions will be given in terms of cell overhead rate and signalling effort for selected scenarios.

Assessing the feasibility of interrupting the transmission of soil-transmitted helminths through mass drug administration: The DeWorm3 cluster randomized trial protocol.

PubMed

Ásbjörnsdóttir, Kristjana Hrönn; Ajjampur, Sitara S Rao; Anderson, Roy M; Bailey, Robin; Gardiner, Iain; Halliday, Katherine E; Ibikounle, Moudachirou; Kalua, Khumbo; Kang, Gagandeep; Littlewood, D Timothy J; Luty, Adrian J F; Means, Arianna Rubin; Oswald, William; Pullan, Rachel L; Sarkar, Rajiv; Schär, Fabian; Szpiro, Adam; Truscott, James E; Werkman, Marleen; Yard, Elodie; Walson, Judd L

2018-01-01

Current control strategies for soil-transmitted helminths (STH) emphasize morbidity control through mass drug administration (MDA) targeting preschool- and school-age children, women of childbearing age and adults in certain high-risk occupations such as agricultural laborers or miners. This strategy is effective at reducing morbidity in those treated but, without massive economic development, it is unlikely it will interrupt transmission. MDA will therefore need to continue indefinitely to maintain benefit. Mathematical models suggest that transmission interruption may be achievable through MDA alone, provided that all age groups are targeted with high coverage. The DeWorm3 Project will test the feasibility of interrupting STH transmission using biannual MDA targeting all age groups. Study sites (population ≥80,000) have been identified in Benin, Malawi and India. Each site will be divided into 40 clusters, to be randomized 1:1 to three years of twice-annual community-wide MDA or standard-of-care MDA, typically annual school-based deworming. Community-wide MDA will be delivered door-to-door, while standard-of-care MDA will be delivered according to national guidelines. The primary outcome is transmission interruption of the STH species present at each site, defined as weighted cluster-level prevalence ≤2% by quantitative polymerase chain reaction (qPCR), 24 months after the final round of MDA. Secondary outcomes include the endline prevalence of STH, overall and by species, and the endline prevalence of STH among children under five as an indicator of incident infections. Secondary analyses will identify cluster-level factors associated with transmission interruption. Prevalence will be assessed using qPCR of stool samples collected from a random sample of cluster residents at baseline, six months after the final round of MDA and 24 months post-MDA. A smaller number of individuals in each cluster will be followed with annual sampling to monitor trends in prevalence and reinfection throughout the trial. ClinicalTrials.gov NCT03014167.

Evaluation of the effects of footwear hygiene protocols on nonspecific bacterial contamination of floor surfaces in an equine hospital.

PubMed

Stockton, Kelly A; Morley, Paul S; Hyatt, Doreene R; Burgess, Brandy A; Patterson, Gage; Dunowska, Magda; Lee, David E

2006-04-01

To evaluate the effects of footwear hygiene protocols on bacterial contamination of floor surfaces in an equine hospital. Field trial. Footwear hygiene protocols evaluated included use of rubber overboots with footbaths and footmats containing a quaternary ammonium disinfectant, rubber overboots with footbaths and footmats containing a peroxygen disinfectant, and no restrictions on footwear type but mandatory use of footbaths and footmats containing a peroxygen disinfectant. Nonspecific aerobic bacterial counts were determined via 2 procedures for sample collection and bacterial enumeration (contact plates vs swabbing combined with use of spread plates), and the effects of each footwear hygiene protocol were compared. There were no consistent findings suggesting that any of the protocols were associated with differences in numbers of bacteria recovered from floor surfaces. Although there were detectable differences in numbers of bacteria recovered in association with different footwear hygiene protocols, differences in least square mean bacterial counts did not appear to be clinically relevant (ie, were < 1 log10). Although cleaning and disinfection of footwear are important aids in reducing the risk of nosocomial transmission of infectious agents in veterinary hospitals, the numbers of aerobic bacteria recovered from floor surfaces were not affected by use of rubber overboots or the types of disinfectant used in this study. Further study is warranted to evaluate the usefulness of footwear hygiene practices relative to their efficacy for reducing transmission of specific pathogens or decreasing nosocomial disease risk.

Using quantitative disease dynamics as a tool for guiding response to avian influenza in poultry in the United States of America☆

PubMed Central

Pepin, K.M.; Spackman, E.; Brown, J.D.; Pabilonia, K.L.; Garber, L.P.; Weaver, J.T.; Kennedy, D.A.; Patyk, K.A.; Huyvaert, K.P.; Miller, R.S.; Franklin, A.B.; Pedersen, K.; Bogich, T.L.; Rohani, P.; Shriner, S.A.; Webb, C.T.; Riley, S.

2014-01-01

Wild birds are the primary source of genetic diversity for influenza A viruses that eventually emerge in poultry and humans. Much progress has been made in the descriptive ecology of avian influenza viruses (AIVs), but contributions are less evident from quantitative studies (e.g., those including disease dynamic models). Transmission between host species, individuals and flocks has not been measured with sufficient accuracy to allow robust quantitative evaluation of alternate control protocols. We focused on the United States of America (USA) as a case study for determining the state of our quantitative knowledge of potential AIV emergence processes from wild hosts to poultry. We identified priorities for quantitative research that would build on existing tools for responding to AIV in poultry and concluded that the following knowledge gaps can be addressed with current empirical data: (1) quantification of the spatio-temporal relationships between AIV prevalence in wild hosts and poultry populations, (2) understanding how the structure of different poultry sectors impacts within-flock transmission, (3) determining mechanisms and rates of between-farm spread, and (4) validating current policy-decision tools with data. The modeling studies we recommend will improve our mechanistic understanding of potential AIV transmission patterns in USA poultry, leading to improved measures of accuracy and reduced uncertainty when evaluating alternative control strategies. PMID:24462191

[Staphylococcus aureus nasal colonization in medical students: importance in nosocomial transmission].

PubMed

López-Aguilera, Sara; Goñi-Yeste, María Del Mar; Barrado, Laura; González-Rodríguez-Salinas, M Carmen; Otero, Joaquín R; Chaves, Fernando

2013-10-01

Staphylococcus aureus is the main pathogen causing nosocomial infections. Health professionals, including medical students, could be a source of transmission. The aims of the study were to determine the rate of nasal carriage of S.aureus susceptible and resistant to methicillin (MRSA) and evaluate the knowledge and adherence that students had about hand hygiene. The study included medical students attached to the Hospital Universitario 12 de Octubre (Madrid, Spain). We collected samples from both nasal vestibules, and the antimicrobial susceptibility was determined on all isolates. Data collection was performed using a self-administered questionnaire that included risk factors for colonization, hygiene habits and knowledge of hand hygiene protocols. Of the 140 students included, 55 (39.3%) were colonized by S.aureus, and 3 (2,1%) by MRSA. The exposure to antibiotics in the last 3 months was lower in colonized students (12.3% vs. 25.9%, P=.03). Self-assessment showed that 56.4% of students almost never washed their hands before to attending to the first patient, and only 38.6% always washed after examining patients. More than a third (35.7%) ignored the hand hygiene protocol, and 38.6% had not received specific formation. Medical students should be included in hospital infection control programs. Hand hygiene training should be given to students before they begin their practices in the hospital. Copyright © 2012 Elsevier España, S.L. All rights reserved.

Development of risk reduction behavioral counseling for Ebola virus disease survivors enrolled in the Sierra Leone Ebola Virus Persistence Study, 2015-2016

PubMed Central

Malik, Tasneem; Ariyarajah, Archchun; Ongpin, Patricia; Hogben, Matthew; McDonald, Suzanna L. R.; Marrinan, Jaclyn; Massaquoi, Thomas; Thorson, Anna; Ervin, Elizabeth; Bernstein, Kyle; Ross, Christine; Liu, William J.; Kroeger, Karen; Durski, Kara N.; Broutet, Nathalie; Knust, Barbara; Deen, Gibrilla F.

2017-01-01

Background During the 2014–2016 West Africa Ebola Virus Disease (EVD) epidemic, the public health community had concerns that sexual transmission of the Ebola virus (EBOV) from EVD survivors was a risk, due to EBOV persistence in body fluids of EVD survivors, particularly semen. The Sierra Leone Ebola Virus Persistence Study was initiated to investigate this risk by assessing EBOV persistence in numerous body fluids of EVD survivors and providing risk reduction counseling based on test results for semen, vaginal fluid, menstrual blood, urine, rectal fluid, sweat, tears, saliva, and breast milk. This publication describes implementation of the counseling protocol and the key lessons learned. Methodology/Principal findings The Ebola Virus Persistence Risk Reduction Behavioral Counseling Protocol was developed from a framework used to prevent transmission of HIV and other sexually transmitted infections. The framework helped to identify barriers to risk reduction and facilitated the development of a personalized risk-reduction plan, particularly around condom use and abstinence. Pre-test and post-test counseling sessions included risk reduction guidance, and post-test counseling was based on the participants’ individual test results. The behavioral counseling protocol enabled study staff to translate the study’s body fluid test results into individualized information for study participants. Conclusions/Significance The Ebola Virus Persistence Risk Reduction Behavioral Counseling Protocol provided guidance to mitigate the risk of EBOV transmission from EVD survivors. It has since been shared with and adapted by other EVD survivor body fluid testing programs and studies in Ebola-affected countries. PMID:28892490

Cross-layer protocols optimized for real-time multimedia services in energy-constrained mobile ad hoc networks

NASA Astrophysics Data System (ADS)

Hortos, William S.

2003-07-01

Mobile ad hoc networking (MANET) supports self-organizing, mobile infrastructures and enables an autonomous network of mobile nodes that can operate without a wired backbone. Ad hoc networks are characterized by multihop, wireless connectivity via packet radios and by the need for efficient dynamic protocols. All routers are mobile and can establish connectivity with other nodes only when they are within transmission range. Importantly, ad hoc wireless nodes are resource-constrained, having limited processing, memory, and battery capacity. Delivery of high quality-ofservice (QoS), real-time multimedia services from Internet-based applications over a MANET is a challenge not yet achieved by proposed Internet Engineering Task Force (IETF) ad hoc network protocols in terms of standard performance metrics such as end-to-end throughput, packet error rate, and delay. In the distributed operations of route discovery and maintenance, strong interaction occurs across MANET protocol layers, in particular, the physical, media access control (MAC), network, and application layers. The QoS requirements are specified for the service classes by the application layer. The cross-layer design must also satisfy the battery-limited energy constraints, by minimizing the distributed power consumption at the nodes and of selected routes. Interactions across the layers are modeled in terms of the set of concatenated design parameters including associated energy costs. Functional dependencies of the QoS metrics are described in terms of the concatenated control parameters. New cross-layer designs are sought that optimize layer interdependencies to achieve the "best" QoS available in an energy-constrained, time-varying network. The protocol design, based on a reactive MANET protocol, adapts the provisioned QoS to dynamic network conditions and residual energy capacities. The cross-layer optimization is based on stochastic dynamic programming conditions derived from time-dependent models of MANET packet flows. Regulation of network behavior is modeled by the optimal control of the conditional rates of multivariate point processes (MVPPs); these rates depend on the concatenated control parameters through a change of probability measure. The MVPP models capture behavior of many service applications, e.g., voice, video and the self-similar behavior of Internet data sessions. Performance verification of the cross-layer protocols, derived from the dynamic programming conditions, can be achieved by embedding the conditions in a reactive routing protocol for MANETs, in a simulation environment, such as the wireless extension of ns-2. A canonical MANET scenario consists of a distributed collection of battery-powered laptops or hand-held terminals, capable of hosting multimedia applications. Simulation details and performance tradeoffs, not presented, remain for a sequel to the paper.

Design and performance evaluation of a distributed OFDMA-based MAC protocol for MANETs.

PubMed

Park, Jaesung; Chung, Jiyoung; Lee, Hyungyu; Lee, Jung-Ryun

2014-01-01

In this paper, we propose a distributed MAC protocol for OFDMA-based wireless mobile ad hoc multihop networks, in which the resource reservation and data transmission procedures are operated in a distributed manner. A frame format is designed considering the characteristics of OFDMA that each node can transmit or receive data to or from multiple nodes simultaneously. Under this frame structure, we propose a distributed resource management method including network state estimation and resource reservation processes. We categorize five types of logical errors according to their root causes and show that two of the logical errors are inevitable while three of them are avoided under the proposed distributed MAC protocol. In addition, we provide a systematic method to determine the advertisement period of each node by presenting a clear relation between the accuracy of estimated network states and the signaling overhead. We evaluate the performance of the proposed protocol in respect of the reservation success rate and the success rate of data transmission. Since our method focuses on avoiding logical errors, it could be easily placed on top of the other resource allocation methods focusing on the physical layer issues of the resource management problem and interworked with them.

A network coding based routing protocol for underwater sensor networks.

PubMed

Wu, Huayang; Chen, Min; Guan, Xin

2012-01-01

Due to the particularities of the underwater environment, some negative factors will seriously interfere with data transmission rates, reliability of data communication, communication range, and network throughput and energy consumption of underwater sensor networks (UWSNs). Thus, full consideration of node energy savings, while maintaining a quick, correct and effective data transmission, extending the network life cycle are essential when routing protocols for underwater sensor networks are studied. In this paper, we have proposed a novel routing algorithm for UWSNs. To increase energy consumption efficiency and extend network lifetime, we propose a time-slot based routing algorithm (TSR).We designed a probability balanced mechanism and applied it to TSR. The theory of network coding is introduced to TSBR to meet the requirement of further reducing node energy consumption and extending network lifetime. Hence, time-slot based balanced network coding (TSBNC) comes into being. We evaluated the proposed time-slot based balancing routing algorithm and compared it with other classical underwater routing protocols. The simulation results show that the proposed protocol can reduce the probability of node conflicts, shorten the process of routing construction, balance energy consumption of each node and effectively prolong the network lifetime.

A Network Coding Based Routing Protocol for Underwater Sensor Networks

PubMed Central

Wu, Huayang; Chen, Min; Guan, Xin

2012-01-01

Due to the particularities of the underwater environment, some negative factors will seriously interfere with data transmission rates, reliability of data communication, communication range, and network throughput and energy consumption of underwater sensor networks (UWSNs). Thus, full consideration of node energy savings, while maintaining a quick, correct and effective data transmission, extending the network life cycle are essential when routing protocols for underwater sensor networks are studied. In this paper, we have proposed a novel routing algorithm for UWSNs. To increase energy consumption efficiency and extend network lifetime, we propose a time-slot based routing algorithm (TSR).We designed a probability balanced mechanism and applied it to TSR. The theory of network coding is introduced to TSBR to meet the requirement of further reducing node energy consumption and extending network lifetime. Hence, time-slot based balanced network coding (TSBNC) comes into being. We evaluated the proposed time-slot based balancing routing algorithm and compared it with other classical underwater routing protocols. The simulation results show that the proposed protocol can reduce the probability of node conflicts, shorten the process of routing construction, balance energy consumption of each node and effectively prolong the network lifetime. PMID:22666045

Design and Implementation of BDS RTCM SSR Message

NASA Astrophysics Data System (ADS)

Xiao, Xia; Cheng, Fang; Liu, Feng; Lu, XiaoChun

2017-09-01

Based on the real-time differential positioning system of Beidou wide area, a set of Beidou high-precision differential information transmission protocol is studied and designed. After the system generates satellite precise orbit and clock difference products, it needs to be sent to the users in a certain data format through C band GEO communication satellite. The transport protocol should be designed according to the data volume and update rate of the system. At the same time, it is necessary to combine the signal system, satellite resources and the restriction and restriction of the receiver implementation technology. It refers to the relevant fields and international similar systems of technology and standards to design. This paper establishes a set of technical indicators which can measure the pros and cons of differential message organization and broadcasting strategy. Through modeling, simulation and actual test, this paper makes a comprehensive comparison of different strategies. Finally, a transmission protocol design scheme which has good performance and meets the system service requirements is presented.

Packet error rate analysis of decode-and-forward free-space optical cooperative networks in the presence of random link blockage

NASA Astrophysics Data System (ADS)

Zdravković, Nemanja; Cvetkovic, Aleksandra; Milic, Dejan; Djordjevic, Goran T.

2017-09-01

This paper analyses end-to-end packet error rate (PER) of a free-space optical decode-and-forward cooperative network over a gamma-gamma atmospheric turbulence channel in the presence of temporary random link blockage. Closed-form analytical expressions for PER are derived for the cases with and without transmission links being prone to blockage. Two cooperation protocols (denoted as 'selfish' and 'pilot-adaptive') are presented and compared, where the latter accounts for the presence of blockage and adapts transmission power. The influence of scintillation, link distance, average transmitted signal power, network topology and probability of an uplink and/or internode link being blocked are discussed when the destination applies equal gain combining. The results show that link blockage caused by obstacles can degrade system performance, causing an unavoidable PER floor. The implementation of the pilot-adaptive protocol improves performance when compared to the selfish protocol, diminishing internode link blockage and lowering the PER floor, especially for larger networks.

Study and Simulation of Enhancements for TCP (Transmission Control Protocol) Performance Over Noisy, High-Latency Links

NASA Technical Reports Server (NTRS)

Shepard, Timothy J.; Partridge, Craig; Coulter, Robert

1997-01-01

The designers of the TCP/IP protocol suite explicitly included support of satellites in their design goals. The goal of the Internet Project was to design a protocol which could be layered over different networking technologies to allow them to be concatenated into an internet. The results of this project included two protocols, IP and TCP. IP is the protocol used by all elements in the network and it defines the standard packet format for IP datagrams. TCP is the end-to-end transport protocol commonly used between end systems on the Internet to derive a reliable bi-directional byte-pipe service from the underlying unreliable IP datagram service. Satellite links are explicitly mentioned in Vint Cerf's 2-page article which appeared in 1980 in CCR [2] to introduce the specifications for IP and TCP. In the past fifteen years, TCP has been demonstrated to work over many differing networking technologies, including over paths including satellites links. So if satellite links were in the minds of the designers from the beginning, what is the problem? The problem is that the performance of TCP has in some cases been disappointing. A goal of the authors of the original specification of TCP was to specify only enough behavior to ensure interoperability. The specification left a number of important decisions, in particular how much data is to be sent when, to the implementor. This was deliberately' done. By leaving performance-related decisions to the implementor, this would allow the protocol TCP to be tuned and adapted to different networks and situations in the future without the need to revise the specification of the protocol, or break interoperability. Interoperability would continue while future implementations would be allowed flexibility to adapt to needs which could not be anticipated at the time of the original protocol design.

Construct mine environment monitoring system based on wireless mesh network

NASA Astrophysics Data System (ADS)

Chen, Xin; Ge, Gengyu; Liu, Yinmei; Cheng, Aimin; Wu, Jun; Fu, Jun

2018-04-01

The system uses wireless Mesh network as a network transmission medium, and strive to establish an effective and reliable underground environment monitoring system. The system combines wireless network technology and embedded technology to monitor the internal data collected in the mine and send it to the processing center for analysis and environmental assessment. The system can be divided into two parts: the main control network module and the data acquisition terminal, and the SPI bus technology is used for mutual communication between them. Multi-channel acquisition and control interface design Data acquisition and control terminal in the analog signal acquisition module, digital signal acquisition module, and digital signal output module. The main control network module running Linux operating system, in which the transplant SPI driver, USB card driver and AODV routing protocol. As a result, the internal data collection and reporting of the mine are realized.

Investigating Bordetella pertussis colonisation and immunity: protocol for an inpatient controlled human infection model

PubMed Central

de Graaf, Hans; Gbesemete, Diane; Gorringe, Andrew R.; Diavatopoulos, Dimitri A.; Kester, Kent E.; Faust, Saul N.; Read, Robert C.

2017-01-01

Introduction We summarise an ethically approved protocol for the development of an experimental human challenge colonisation model. Globally Bordetella pertussis is one of the leading causes of vaccine-preventable death. Many countries have replaced whole cell vaccines with acellular vaccines over the last 20 years during which pertussis appears to be resurgent in a number of countries in the developed world that boast high immunisation coverage. The acellular vaccine provides relatively short-lived immunity and, in contrast to whole cell vaccines, may be less effective against colonisation and subsequent transmission. To improve vaccine strategies, a greater understanding of human B. pertussis colonisation is required. This article summarises a protocol and does not contain any results. Methods and analysis A controlled human colonisation model will be developed over two phases. In phase A, a low dose of the inoculum will be given intranasally to healthy participants. This dose will be escalated or de-escalated until colonisation is achieved in approximately 70% (95% CI 47% to 93%) of the exposed volunteers without causing disease. The colonisation period, shedding and exploratory immunology will be assessed during a 17-day inpatient stay and follow-up over 1 year. The dose of inoculum that achieves 70% colonisation will then be confirmed in phase B, comparing healthy participants exposed to B. pertussis with a control group receiving a sham inoculum. Ethics and dissemination This study has been approved by the ethical committee reference: 17/SC/0006, 24 February 2017. Findings will be published in peer-reviewed open access journals as soon as possible. PMID:29025851

An energy-efficient transmission scheme for real-time data in wireless sensor networks.

PubMed

Kim, Jin-Woo; Barrado, José Ramón Ramos; Jeon, Dong-Keun

2015-05-20

The Internet of things (IoT) is a novel paradigm where all things or objects in daily life can communicate with other devices and provide services over the Internet. Things or objects need identifying, sensing, networking and processing capabilities to make the IoT paradigm a reality. The IEEE 802.15.4 standard is one of the main communication protocols proposed for the IoT. The IEEE 802.15.4 standard provides the guaranteed time slot (GTS) mechanism that supports the quality of service (QoS) for the real-time data transmission. In spite of some QoS features in IEEE 802.15.4 standard, the problem of end-to-end delay still remains. In order to solve this problem, we propose a cooperative medium access scheme (MAC) protocol for real-time data transmission. We also evaluate the performance of the proposed scheme through simulation. The simulation results demonstrate that the proposed scheme can improve the network performance.

An Energy-Efficient Transmission Scheme for Real-Time Data in Wireless Sensor Networks

PubMed Central

Kim, Jin-Woo; Barrado, José Ramón Ramos; Jeon, Dong-Keun

2015-01-01

The Internet of things (IoT) is a novel paradigm where all things or objects in daily life can communicate with other devices and provide services over the Internet. Things or objects need identifying, sensing, networking and processing capabilities to make the IoT paradigm a reality. The IEEE 802.15.4 standard is one of the main communication protocols proposed for the IoT. The IEEE 802.15.4 standard provides the guaranteed time slot (GTS) mechanism that supports the quality of service (QoS) for the real-time data transmission. In spite of some QoS features in IEEE 802.15.4 standard, the problem of end-to-end delay still remains. In order to solve this problem, we propose a cooperative medium access scheme (MAC) protocol for real-time data transmission. We also evaluate the performance of the proposed scheme through simulation. The simulation results demonstrate that the proposed scheme can improve the network performance. PMID:26007722

UMDR: Multi-Path Routing Protocol for Underwater Ad Hoc Networks with Directional Antenna

NASA Astrophysics Data System (ADS)

Yang, Jianmin; Liu, Songzuo; Liu, Qipei; Qiao, Gang

2018-01-01

This paper presents a new routing scheme for underwater ad hoc networks based on directional antennas. Ad hoc networks with directional antennas have become a hot research topic because of space reuse may increase networks capacity. At present, researchers have applied traditional self-organizing routing protocols (such as DSR, AODV) [1] [2] on this type of networks, and the routing scheme is based on the shortest path metric. However, such routing schemes often suffer from long transmission delays and frequent link fragmentation along the intermediate nodes of the selected route. This is caused by a unique feature of directional transmission, often called as “deafness”. In this paper, we take a different approach to explore the advantages of space reuse through multipath routing. This paper introduces the validity of the conventional routing scheme in underwater ad hoc networks with directional antennas, and presents a special design of multipath routing algorithm for directional transmission. The experimental results show a significant performance improvement in throughput and latency.

Compression and Transmission of RF Signals for Telediagnosis

NASA Astrophysics Data System (ADS)

Seko, Toshihiro; Doi, Motonori; Oshiro, Osamu; Chihara, Kunihiro

2000-05-01

Health care is a critical issue nowadays. Much emphasis is given to quality care for all people. Telediagnosis has attracted public attention. We propose a new method of ultrasound image transmission for telediagnosis. In conventional methods, video image signals are transmitted. In our method, the RF signals which are acquired by an ultrasound probe, are transmitted. The RF signals can be transformed to color Doppler images or high-resolution images by a receiver. Because a stored form is adopted, the proposed system can be realized with existent technology such as hyper text transfer protocol (HTTP) and file transfer protocol (FTP). In this paper, we describe two lossless compression methods which specialize in the transmission of RF signals. One of the methods uses the characteristics of the RF signal. In the other method, the amount of the data is reduced. Measurements were performed in water targeting an iron block and triangular Styrofoam. Additionally, abdominal fat measurement was performed. Our method achieved a compression rate of 13% with 8 bit data.

Adaptive mechanism-based congestion control for networked systems

NASA Astrophysics Data System (ADS)

Liu, Zhi; Zhang, Yun; Chen, C. L. Philip

2013-03-01

In order to assure the communication quality in network systems with heavy traffic and limited bandwidth, a new ATRED (adaptive thresholds random early detection) congestion control algorithm is proposed for the congestion avoidance and resource management of network systems. Different to the traditional AQM (active queue management) algorithms, the control parameters of ATRED are not configured statically, but dynamically adjusted by the adaptive mechanism. By integrating with the adaptive strategy, ATRED alleviates the tuning difficulty of RED (random early detection) and shows a better control on the queue management, and achieve a more robust performance than RED under varying network conditions. Furthermore, a dynamic transmission control protocol-AQM control system using ATRED controller is introduced for the systematic analysis. It is proved that the stability of the network system can be guaranteed when the adaptive mechanism is finely designed. Simulation studies show the proposed ATRED algorithm achieves a good performance in varying network environments, which is superior to the RED and Gentle-RED algorithm, and providing more reliable service under varying network conditions.

Continuous-variable measurement-device-independent quantum key distribution with photon subtraction

NASA Astrophysics Data System (ADS)

Ma, Hong-Xin; Huang, Peng; Bai, Dong-Yun; Wang, Shi-Yu; Bao, Wan-Su; Zeng, Gui-Hua

2018-04-01

It has been found that non-Gaussian operations can be applied to increase and distill entanglement between Gaussian entangled states. We show the successful use of the non-Gaussian operation, in particular, photon subtraction operation, on the continuous-variable measurement-device-independent quantum key distribution (CV-MDI-QKD) protocol. The proposed method can be implemented based on existing technologies. Security analysis shows that the photon subtraction operation can remarkably increase the maximal transmission distance of the CV-MDI-QKD protocol, which precisely make up for the shortcoming of the original CV-MDI-QKD protocol, and one-photon subtraction operation has the best performance. Moreover, the proposed protocol provides a feasible method for the experimental implementation of the CV-MDI-QKD protocol.

Advanced Communications Technology Satellite Now Operating in an Inclined Orbit

NASA Technical Reports Server (NTRS)

Bauer, Robert A.

1999-01-01

The Advanced Communications Technology Satellite (ACTS) system has been modified to support operation in an inclined orbit that is virtually transparent to users, and plans are to continue this final phase of its operation through September 2000. The next 2 years of ACTS will provide a new opportunity for using the technologies that this system brought online over 5 years ago and that are still being used to resolve the technical issues that face NASA and the satellite industry in the area of seamless networking and interoperability with terrestrial systems. New goals for ACTS have been defined that align the program with recent changes in NASA and industry. ACTS will be used as a testbed to: Show how NASA and other Government agencies can use commercial systems for 1. future support of their operations Test, characterize, and resolve technical issues in using advanced communications 2. protocols such as asynchronous transfer mode (ATM) and transmission control protocol/Internet protocol (TCP/IP) over long latency links as found when interoperating satellites with terrestrial systems Evaluate narrow-spot-beam Ka-band satellite operation in an inclined orbit 3. Verify Ka-band satellite technologies since no other Ka-band system is yet 4. available in the United States

Strategies for Optimal MAC Parameters Tuning in IEEE 802.15.6 Wearable Wireless Sensor Networks.

PubMed

Alam, Muhammad Mahtab; Ben Hamida, Elyes

2015-09-01

Wireless body area networks (WBAN) has penetrated immensely in revolutionizing the classical heath-care system. Recently, number of WBAN applications has emerged which introduce potential limits to existing solutions. In particular, IEEE 802.15.6 standard has provided great flexibility, provisions and capabilities to deal emerging applications. In this paper, we investigate the application-specific throughput analysis by fine-tuning the physical (PHY) and medium access control (MAC) parameters of the IEEE 802.15.6 standard. Based on PHY characterizations in narrow band, at the MAC layer, carrier sense multiple access collision avoidance (CSMA/CA) and scheduled access protocols are extensively analyzed. It is concluded that, IEEE 802.15.6 standard can satisfy most of the WBANs applications throughput requirements by maximum achieving 680 Kbps. However, those emerging applications which require high quality audio or video transmissions, standard is not able to meet their constraints. Moreover, delay, energy efficiency and successful packet reception are considered as key performance metrics for comparing the MAC protocols. CSMA/CA protocol provides the best results to meet the delay constraints of medical and non-medical WBAN applications. Whereas, the scheduled access approach, performs very well both in energy efficiency and packet reception ratio.

Toxoplasma Gondii and Pre-treatment Protocols for Polymerase Chain Reaction Analysis of Milk Samples: A Field Trial in Sheep from Southern Italy.

PubMed

Vismarra, Alice; Barilli, Elena; Miceli, Maura; Mangia, Carlo; Bacci, Cristina; Brindani, Franco; Kramer, Laura

2017-01-24

Toxoplasmosis is a zoonotic disease caused by the protozoan Toxoplasma gondii. Ingestion of raw milk has been suggested as a risk for transmission to humans. Here the authors evaluated pre-treatment protocols for DNA extraction on T. gondii tachyzoite-spiked sheep milk with the aim of identifying the method that resulted in the most rapid and reliable polymerase chain reaction (PCR) positivity. This protocol was then used to analyse milk samples from sheep of three different farms in Southern Italy, including real time PCR for DNA quantification and PCR-restriction fragment length polymorphism for genotyping. The pre-treatment protocol using ethylenediaminetetraacetic acid and Tris-HCl to remove casein gave the best results in the least amount of time compared to the others on spiked milk samples. One sample of 21 collected from sheep farms was positive on one-step PCR, real time PCR and resulted in a Type I genotype at one locus (SAG3). Milk usually contains a low number of tachyzoites and this could be a limiting factor for molecular identification. Our preliminary data has evaluated a rapid, cost-effective and sensitive protocol to treat milk before DNA extraction. The results of the present study also confirm the possibility of T. gondii transmission through consumption of raw milk and its unpasteurised derivatives.

A Source Anonymity-Based Lightweight Secure AODV Protocol for Fog-Based MANET

PubMed Central

Fang, Weidong; Zhang, Wuxiong; Xiao, Jinchao; Yang, Yang; Chen, Wei

2017-01-01

Fog-based MANET (Mobile Ad hoc networks) is a novel paradigm of a mobile ad hoc network with the advantages of both mobility and fog computing. Meanwhile, as traditional routing protocol, ad hoc on-demand distance vector (AODV) routing protocol has been applied widely in fog-based MANET. Currently, how to improve the transmission performance and enhance security are the two major aspects in AODV’s research field. However, the researches on joint energy efficiency and security seem to be seldom considered. In this paper, we propose a source anonymity-based lightweight secure AODV (SAL-SAODV) routing protocol to meet the above requirements. In SAL-SAODV protocol, source anonymous and secure transmitting schemes are proposed and applied. The scheme involves the following three parts: the source anonymity algorithm is employed to achieve the source node, without being tracked and located; the improved secure scheme based on the polynomial of CRC-4 is applied to substitute the RSA digital signature of SAODV and guarantee the data integrity, in addition to reducing the computation and energy consumption; the random delayed transmitting scheme (RDTM) is implemented to separate the check code and transmitted data, and achieve tamper-proof results. The simulation results show that the comprehensive performance of the proposed SAL-SAODV is a trade-off of the transmission performance, energy efficiency, and security, and better than AODV and SAODV. PMID:28629142

A Source Anonymity-Based Lightweight Secure AODV Protocol for Fog-Based MANET.

PubMed

Fang, Weidong; Zhang, Wuxiong; Xiao, Jinchao; Yang, Yang; Chen, Wei

2017-06-17

Fog-based MANET (Mobile Ad hoc networks) is a novel paradigm of a mobile ad hoc network with the advantages of both mobility and fog computing. Meanwhile, as traditional routing protocol, ad hoc on-demand distance vector (AODV) routing protocol has been applied widely in fog-based MANET. Currently, how to improve the transmission performance and enhance security are the two major aspects in AODV's research field. However, the researches on joint energy efficiency and security seem to be seldom considered. In this paper, we propose a source anonymity-based lightweight secure AODV (SAL-SAODV) routing protocol to meet the above requirements. In SAL-SAODV protocol, source anonymous and secure transmitting schemes are proposed and applied. The scheme involves the following three parts: the source anonymity algorithm is employed to achieve the source node, without being tracked and located; the improved secure scheme based on the polynomial of CRC-4 is applied to substitute the RSA digital signature of SAODV and guarantee the data integrity, in addition to reducing the computation and energy consumption; the random delayed transmitting scheme (RDTM) is implemented to separate the check code and transmitted data, and achieve tamper-proof results. The simulation results show that the comprehensive performance of the proposed SAL-SAODV is a trade-off of the transmission performance, energy efficiency, and security, and better than AODV and SAODV.

A statistical frame based TDMA protocol for human body communication.

PubMed

Nie, Zedong; Li, Zhao; Huang, Renwei; Liu, Yuhang; Li, Jingzhen; Wang, Lei

2015-07-09

Human body communication (HBC) using the human body as the transmission medium, which has been regarded as one of the most promising short-range communications in wireless body area networks (WBAN). Compared to the traditional wireless networks, two challenges are existed in HBC based WBAN. (1) Its sensor nodes should be energy saving since it is inconvenient to replace or recharge the battery on these sensor nodes; (2) the coordinator should be able to react dynamically and rapidly to the burst traffic triggered by sensing events. Those burst traffic conditions include vital physical signal (electrocardiogram, electroencephalogram etc.) monitoring, human motion detection (fall detection, activity monitoring, gesture recognition, motion sensing etc.) and so on. To cope with aforementioned challenges, a statistical frame based TDMA (S-TDMA) protocol with multi-constrained (energy, delay, transmission efficiency and emergency management) service is proposed in this paper. The scenarios where burst traffic is often triggered rapidly with low power consumption and low delay is handled in our proposed S-TDMA. A beacon frame with the contained synchronous and poll information is designed to reduce the possibility of collisions of request frames. A statistical frame which broadcasts the unified scheduling information is adopted to avoid packet collisions, idle listening and overhearing. Dynamic time slot allocation mechanism is presented to manage the burst traffic and reduce the active period in each beacon period. An emergency mechanism is proposed for vital signals to be transmitted. The theory analysis is proceed and the result is evaluated in the hardware platform. To verify its feasibility, S-TDMA was fully implemented on our independently-developed HBC platform where four sensor nodes and a coordinator are fastened on a human body. Experiment results show that S-TDMA costs 89.397 mJ every 20 s when the payload size is 122 bytes, 9.51% lower than Lightweight MAC (LMAC); the average data latency of S-TDMA is 6.3 ms, 7.02% lower than Preamble-based TDMA (PB-TDMA); the transmission efficiency of S-TDMA is 93.67%, 4.83% higher than IEEE 802.15.6 carrier sense multiple access/collision avoidance (CSMA/CA) protocol. With respect to the challenges of HBC based WBANs, a novel S-TDMA protocol was proposed in this paper. Compared to the traditional protocols, the results demonstrate that S-TDMA successfully meets the delay and transmission efficiency requirements of HBC while keeping a low energy consumption. We also believe that our S-TDMA protocol will promote development of HBC in wearable applications.

Project LifeSkills - a randomized controlled efficacy trial of a culturally tailored, empowerment-based, and group-delivered HIV prevention intervention for young transgender women: study protocol.

PubMed

Kuhns, Lisa M; Mimiaga, Matthew J; Reisner, Sari L; Biello, Katie; Garofalo, Robert

2017-09-16

Transgender women in the U.S. have an alarmingly high incidence rate of HIV infection; condomless anal and vaginal sex is the primary risk behavior driving transmission. Young transgender women are the subpopulation at the highest risk for HIV. Despite this, there are no published randomized controlled efficacy trials testing interventions to reduce sexual risk for HIV among this group. This paper describes the design of a group-based intervention trial to reduce sexual risk for HIV acquisition and transmission in young transgender women. This study, funded by the National Institutes of Health, is a randomized controlled trial of a culturally-specific, empowerment-based, and group-delivered six-session HIV prevention intervention, Project LifeSkills, among sexually active young transgender women, ages 16-29 years in Boston and Chicago. Participants are randomized (2:2:1) to either the LifeSkills intervention, standard of care only, or a diet and nutrition time- and attention-matched control. At enrollment, all participants receive standardized HIV pre- and post-test counseling and screening for HIV and urogenital gonorrhea and chlamydia infections. The primary outcome is difference in the rate of change in the number of self-reported condomless anal or vaginal sex acts during the prior 4-months, assessed at baseline, 4-, 8-, and 12-month follow-up visits. Behavioral interventions to reduce sexual risk for HIV acquisition and transmission are sorely needed for young transgender women. This study will provide evidence to determine feasibility and efficacy in one of the first rigorously designed trials for this population. ClinicalTrials.gov number, NCT01575938 , registered March 29, 2012.

47 CFR 51.305 - Interconnection.

Code of Federal Regulations, 2014 CFR

2014-10-01

..., interconnection with the incumbent LEC's network: (1) For the transmission and routing of telephone exchange... interface or protocol standards shall constitute evidence of the substantial similarity of network...

47 CFR 51.305 - Interconnection.

Code of Federal Regulations, 2012 CFR

2012-10-01

..., interconnection with the incumbent LEC's network: (1) For the transmission and routing of telephone exchange... interface or protocol standards shall constitute evidence of the substantial similarity of network...

47 CFR 51.305 - Interconnection.

Code of Federal Regulations, 2013 CFR

2013-10-01

..., interconnection with the incumbent LEC's network: (1) For the transmission and routing of telephone exchange... interface or protocol standards shall constitute evidence of the substantial similarity of network...

47 CFR 51.305 - Interconnection.

Code of Federal Regulations, 2011 CFR

2011-10-01

..., interconnection with the incumbent LEC's network: (1) For the transmission and routing of telephone exchange... interface or protocol standards shall constitute evidence of the substantial similarity of network...

A Survey on Underwater Acoustic Sensor Network Routing Protocols.

PubMed

Li, Ning; Martínez, José-Fernán; Meneses Chaus, Juan Manuel; Eckert, Martina

2016-03-22

Underwater acoustic sensor networks (UASNs) have become more and more important in ocean exploration applications, such as ocean monitoring, pollution detection, ocean resource management, underwater device maintenance, etc. In underwater acoustic sensor networks, since the routing protocol guarantees reliable and effective data transmission from the source node to the destination node, routing protocol design is an attractive topic for researchers. There are many routing algorithms have been proposed in recent years. To present the current state of development of UASN routing protocols, we review herein the UASN routing protocol designs reported in recent years. In this paper, all the routing protocols have been classified into different groups according to their characteristics and routing algorithms, such as the non-cross-layer design routing protocol, the traditional cross-layer design routing protocol, and the intelligent algorithm based routing protocol. This is also the first paper that introduces intelligent algorithm-based UASN routing protocols. In addition, in this paper, we investigate the development trends of UASN routing protocols, which can provide researchers with clear and direct insights for further research.

A Survey on Underwater Acoustic Sensor Network Routing Protocols

PubMed Central

Li, Ning; Martínez, José-Fernán; Meneses Chaus, Juan Manuel; Eckert, Martina

2016-01-01

Underwater acoustic sensor networks (UASNs) have become more and more important in ocean exploration applications, such as ocean monitoring, pollution detection, ocean resource management, underwater device maintenance, etc. In underwater acoustic sensor networks, since the routing protocol guarantees reliable and effective data transmission from the source node to the destination node, routing protocol design is an attractive topic for researchers. There are many routing algorithms have been proposed in recent years. To present the current state of development of UASN routing protocols, we review herein the UASN routing protocol designs reported in recent years. In this paper, all the routing protocols have been classified into different groups according to their characteristics and routing algorithms, such as the non-cross-layer design routing protocol, the traditional cross-layer design routing protocol, and the intelligent algorithm based routing protocol. This is also the first paper that introduces intelligent algorithm-based UASN routing protocols. In addition, in this paper, we investigate the development trends of UASN routing protocols, which can provide researchers with clear and direct insights for further research. PMID:27011193

Development and Operation of Dual-Mode Analyzers for Wireless Power Consortium/Power Matters Alliance Wireless Power Systems.

PubMed

Um, Keehong

2016-05-01

We have designed a protocol analyzer to be used in wireless power systems and analyzed the operation of wireless chargers defined by standards of Qi of Wireless Power Consortium (WPC) and Power Matters Alliance (PMA) protocols. The integrated circuit (IC, or microchip) developed so far for wireless power transmission is not easily adopted by chargers for specific purposes. A device for measuring the performance of test equipment currently available is required to transform and expand the types of protocol. Since a protocol analyzer with these functions is required, we have developed a device that can analyze the two protocols of WPC and PMA at the same time. As a result of our research, we present a dual-mode system that can analyze the protocols of both WPC and PMA.

Finite-key security analyses on passive decoy-state QKD protocols with different unstable sources.

PubMed

Song, Ting-Ting; Qin, Su-Juan; Wen, Qiao-Yan; Wang, Yu-Kun; Jia, Heng-Yue

2015-10-16

In quantum communication, passive decoy-state QKD protocols can eliminate many side channels, but the protocols without any finite-key analyses are not suitable for in practice. The finite-key securities of passive decoy-state (PDS) QKD protocols with two different unstable sources, type-II parametric down-convention (PDC) and phase randomized weak coherent pulses (WCPs), are analyzed in our paper. According to the PDS QKD protocols, we establish an optimizing programming respectively and obtain the lower bounds of finite-key rates. Under some reasonable values of quantum setup parameters, the lower bounds of finite-key rates are simulated. The simulation results show that at different transmission distances, the affections of different fluctuations on key rates are different. Moreover, the PDS QKD protocol with an unstable PDC source can resist more intensity fluctuations and more statistical fluctuation.

Seaworthy Quantum Key Distribution Design and Validation (SEAKEY)

DTIC Science & Technology

2014-10-30

to single photon detection, at comparable detection efficiencies. On the other hand, error-correction codes are better developed for small-alphabet...protocol is several orders of magnitude better than the Shapiro protocol, which needs entangled states. The bits/mode performance achieved by our...putting together a software tool implemented in MATLAB , which talks to the MODTRAN database via an intermediate numerical dump of transmission data

Design and research on the platform of network manufacture product electronic trading

NASA Astrophysics Data System (ADS)

Zhou, Zude; Liu, Quan; Jiang, Xuemei

2003-09-01

With the rapid globalization of market and business, E-trading affects every manufacture enterprise. However, the security of network manufacturing products of transmission on Internet is very important. In this paper we discussed the protocol of fair exchange and platform for network manufacture products E-trading based on fair exchange protocol and digital watermarking techniques. The platform realized reliable and copyright protection.

A quarantine process for the resolution of duodenoscope-associated transmission of multidrug-resistant Escherichia coli.

PubMed

Ross, Andrew S; Baliga, Christopher; Verma, Punam; Duchin, Jeffrey; Gluck, Michael

2015-09-01

Because of their complex design, duodenoscopes have been long recognized to be difficult to fully disinfect and may play a role in transmission of bacteria between patients. Recent reports of duodenoscope-associated carbapenem-resistant enterobacteriaceae transmission have confirmed these suspicions. An outbreak of a multidrug resistant strain of Escherichia coli was recently reported at our institution. Herein we report the results of our investigation and the process improvements that we deployed in an effort to contain the outbreak. A full investigation into the environment, endoscopists, infection control practices, high-level disinfection process as well as endoscopes was undertaken in conjunction with the local county health authority and the Centers for Disease Control and Prevention. Duodenoscopes were cultured and quarantined for 48 hours until negative cultures were obtained. Ergonomic changes were made to the endoscope reprocessing area, duodenoscopes were returned for routine maintenance, and surveillance cultures were obtained from all patients undergoing ERCP. Between November 2012 and August 2013, 32 patients were found to harbor 1 of 2 clonal strains of multidrug-resistant E coli, all of whom had undergone ERCP or duodenoscopy. A total of 1149 ERCPs were performed during this time period. Seven patients died within 31 days of the organism being identified in culture, 16 patients died overall by March 2015. The exact contribution of E coli to death is unclear because most patients had underlying late-stage malignancy or other severe medical comorbidities. No breach in high-level disinfection protocol or infection control practices was identified. The clonal strain of E coli was identified in culture on 4 of 8 duodenoscopes, 3 of which required critical repairs despite lack of obvious malfunction. The defect rate in high-level disinfection of duodenoscopes was 2% over a 1-year period. The implemented quality improvements, subsequent to which 1625 ERCPs have been performed, were successful in halting the outbreak. The existing manufacturer-recommended high-level disinfection protocols for duodenoscopes are inadequate. Although the ultimate solution may be a design change to the instrument, the timeline for such a change appears long and potentially difficult to exact. In the interim, a reliable method to ensure that bacterial pathogens are not present on the duodenoscope after high-level disinfection is needed. Copyright © 2015 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.

CDP - Adaptive Supervisory Control and Data Acquisition (SCADA) Technology for Infrastructure Protection

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

Marco Carvalho; Richard Ford

2012-05-14

Supervisory Control and Data Acquisition (SCADA) Systems are a type of Industrial Control System characterized by the centralized (or hierarchical) monitoring and control of geographically dispersed assets. SCADA systems combine acquisition and network components to provide data gathering, transmission, and visualization for centralized monitoring and control. However these integrated capabilities, especially when built over legacy systems and protocols, generally result in vulnerabilities that can be exploited by attackers, with potentially disastrous consequences. Our research project proposal was to investigate new approaches for secure and survivable SCADA systems. In particular, we were interested in the resilience and adaptability of large-scale mission-criticalmore » monitoring and control infrastructures. Our research proposal was divided in two main tasks. The first task was centered on the design and investigation of algorithms for survivable SCADA systems and a prototype framework demonstration. The second task was centered on the characterization and demonstration of the proposed approach in illustrative scenarios (simulated or emulated).« less

LANES - LOCAL AREA NETWORK EXTENSIBLE SIMULATOR

NASA Technical Reports Server (NTRS)

Gibson, J.

1994-01-01

The Local Area Network Extensible Simulator (LANES) provides a method for simulating the performance of high speed local area network (LAN) technology. LANES was developed as a design and analysis tool for networking on board the Space Station. The load, network, link and physical layers of a layered network architecture are all modeled. LANES models to different lower-layer protocols, the Fiber Distributed Data Interface (FDDI) and the Star*Bus. The load and network layers are included in the model as a means of introducing upper-layer processing delays associated with message transmission; they do not model any particular protocols. FDDI is an American National Standard and an International Organization for Standardization (ISO) draft standard for a 100 megabit-per-second fiber-optic token ring. Specifications for the LANES model of FDDI are taken from the Draft Proposed American National Standard FDDI Token Ring Media Access Control (MAC), document number X3T9.5/83-16 Rev. 10, February 28, 1986. This is a mature document describing the FDDI media-access-control protocol. Star*Bus, also known as the Fiber Optic Demonstration System, is a protocol for a 100 megabit-per-second fiber-optic star-topology LAN. This protocol, along with a hardware prototype, was developed by Sperry Corporation under contract to NASA Goddard Space Flight Center as a candidate LAN protocol for the Space Station. LANES can be used to analyze performance of a networking system based on either FDDI or Star*Bus under a variety of loading conditions. Delays due to upper-layer processing can easily be nullified, allowing analysis of FDDI or Star*Bus as stand-alone protocols. LANES is a parameter-driven simulation; it provides considerable flexibility in specifying both protocol an run-time parameters. Code has been optimized for fast execution and detailed tracing facilities have been included. LANES was written in FORTRAN 77 for implementation on a DEC VAX under VMS 4.6. It consists of two programs, a simulation program and a user-interface program. The simulation program requires the SLAM II simulation library from Pritsker and Associates, W. Lafayette IN; the user interface is implemented using the Ingres database manager from Relational Technology, Inc. Information about running the simulation program without the user-interface program is contained in the documentation. The memory requirement is 129,024 bytes. LANES was developed in 1988.

Evidence of transmission of Mycobacterium tuberculosis by random amplified polymorphic DNA (RAPD) fingerprinting in Taipei City, Taiwan.

PubMed Central

Harn, H J; Shen, K L; Ho, L I; Yu, K W; Liu, G C; Yueh, K C; Lee, J H

1997-01-01

AIMS: To determine, by strain identification of Mycobacterium tuberculosis, whether transmission has occurred between individuals or whether new strains are present. METHODS: A rapid protocol for random amplified polymorphic DNA (RAPD) analysis was developed. This protocol was applied to 64 strains of M tuberculosis that had been confirmed by culture and microbiological methods. RESULTS: There are five groups of M tuberculosis prevalent in Taipei city, Taiwan. The major types are groups I and III. Groups I and II had been prevalent until the end of last year when, according to our group analysis, they had been eradicated. However, group III was continuously present from the middle of 1995 to the middle of 1996, and group IV was present at the end of both years, which indicated that both groups were transmitted continuously. These clustered strains had demographic characteristics consistent with a finding of transmission tuberculosis. Also, there were 13 of 64 strains with unique RAPD fingerprints that were inferred to be due primarily to the reactivation of infection. In the drug resistance analysis, the major type represented included group III and part of group IV. CONCLUSIONS: Our preliminary data imply, not only that the prevalence of M tuberculosis in Taipei city is due to transmission rather than reactivation, but that drug resistance also may play a role in tuberculosis transmission. Images PMID:9378819

Packet based serial link realized in FPGA dedicated for high resolution infrared image transmission

NASA Astrophysics Data System (ADS)

Bieszczad, Grzegorz

2015-05-01

In article the external digital interface specially designed for thermographic camera built in Military University of Technology is described. The aim of article is to illustrate challenges encountered during design process of thermal vision camera especially related to infrared data processing and transmission. Article explains main requirements for interface to transfer Infra-Red or Video digital data and describes the solution which we elaborated based on Low Voltage Differential Signaling (LVDS) physical layer and signaling scheme. Elaborated link for image transmission is built using FPGA integrated circuit with built-in high speed serial transceivers achieving up to 2500Gbps throughput. Image transmission is realized using proprietary packet protocol. Transmission protocol engine was described in VHDL language and tested in FPGA hardware. The link is able to transmit 1280x1024@60Hz 24bit video data using one signal pair. Link was tested to transmit thermal-vision camera picture to remote monitor. Construction of dedicated video link allows to reduce power consumption compared to solutions with ASIC based encoders and decoders realizing video links like DVI or packed based Display Port, with simultaneous reduction of wires needed to establish link to one pair. Article describes functions of modules integrated in FPGA design realizing several functions like: synchronization to video source, video stream packeting, interfacing transceiver module and dynamic clock generation for video standard conversion.

Low Resolution Picture Transmission (LRPT) Demonstration System. Phase II; 1.0

NASA Technical Reports Server (NTRS)

Fong, Wai; Yeh, Pen-Shu; Duran, Steve; Sank, Victor; Nyugen, Xuan; Xia, Wei; Day, John H. (Technical Monitor)

2002-01-01

Low-Resolution Picture Transmission (LRPT) is a proposed standard for direct broadcast transmission of satellite weather images. This standard is a joint effort by the European Organization for the Exploitation of Meteorological Satellites (EUMETSAT) and NOAA. As a digital transmission scheme, its purpose is to replace the current analog Automatic Picture Transmission (APT) system for use in the Meteorological Operational (METOP) satellites. GSFC has been tasked to build an LRPT Demonstration System (LDS). Its main objective is to develop or demonstrate the feasibility of a low-cost receiver utilizing a PC as the primary processing component and determine the performance of the protocol in the simulated Radio Frequency (RF) environment. The approach would consist of two phases.

Network Coded Cooperative Communication in a Real-Time Wireless Hospital Sensor Network.

PubMed

Prakash, R; Balaji Ganesh, A; Sivabalan, Somu

2017-05-01

The paper presents a network coded cooperative communication (NC-CC) enabled wireless hospital sensor network architecture for monitoring health as well as postural activities of a patient. A wearable device, referred as a smartband is interfaced with pulse rate, body temperature sensors and an accelerometer along with wireless protocol services, such as Bluetooth and Radio-Frequency transceiver and Wi-Fi. The energy efficiency of wearable device is improved by embedding a linear acceleration based transmission duty cycling algorithm (NC-DRDC). The real-time demonstration is carried-out in a hospital environment to evaluate the performance characteristics, such as power spectral density, energy consumption, signal to noise ratio, packet delivery ratio and transmission offset. The resource sharing and energy efficiency features of network coding technique are improved by proposing an algorithm referred as network coding based dynamic retransmit/rebroadcast decision control (LA-TDC). From the experimental results, it is observed that the proposed LA-TDC algorithm reduces network traffic and end-to-end delay by an average of 27.8% and 21.6%, respectively than traditional network coded wireless transmission. The wireless architecture is deployed in a hospital environment and results are then successfully validated.

The high speed buffer board: A SAIL EIA-485 communications accelerator card for the vector measuring current meter

NASA Astrophysics Data System (ADS)

Singer, Robin; Butler, Douglas M.

1990-07-01

A High Speed Buffer Board (HSBB) was developed for the Vector Measuring Current Meter (VMCM) to implement the transmission of data at 9600 baud over an EIA-485 link. The HSBB significantly extends the VMCM communication functionality, which was previously limited to 300 baud transmission via 20mA current loop or FSK telemetry. The increased speed allows rapid sampling of a large number of current meters on a common cable and the EIA-485 circuitry, which was designed for low power operation, provides a useful multipoint communication method for data transmission over long cable lengths. SAIL protocol (IEEE 997) was utilized to coordinate data transfer by the instruments on a common link. An MC68HC11 microcontroller resides in the VMCM, buffering data it receives at 300 baud from the VMCM UART. In response to a jumper selectable SAIL address, the MC68HC11 offloads the data 9600 baud via EIA-485 to the SAIL controller. Synchronous data collection from many instruments is ensured by the SAIL synoptic set command and an embedded resynchronization/reset command. The low power consumption allows deployments of six months or more with a standard VMCM battery stack.

West Nile virus transmission: results from the integrated surveillance system in Italy, 2008 to 2015.

PubMed

Rizzo, Caterina; Napoli, Christian; Venturi, Giulietta; Pupella, Simonetta; Lombardini, Letizia; Calistri, Paolo; Monaco, Federica; Cagarelli, Roberto; Angelini, Paola; Bellini, Romeo; Tamba, Marco; Piatti, Alessandra; Russo, Francesca; Palù, Giorgio; Chiari, Mario; Lavazza, Antonio; Bella, Antonino

2016-09-15

In Italy a national Plan for the surveillance of imported and autochthonous human vector-borne diseases (chikungunya, dengue, Zika virus disease and West Nile virus (WNV) disease) that integrates human and veterinary (animals and vectors) surveillance, is issued and revised annually according with the observed epidemiological changes. Here we describe results of the WNV integrated veterinary and human surveillance systems in Italy from 2008 to 2015. A real time data exchange protocol is in place between the surveillance systems to rapidly identify occurrence of human and animal cases and to define and update the map of affected areas i.e. provinces during the vector activity period from June to October. WNV continues to cause severe illnesses in Italy during every transmission season, albeit cases are sporadic and the epidemiology varies by virus lineage and geographic area. The integration of surveillance activities and a multidisciplinary approach made it possible and have been fundamental in supporting implementation of and/or strengthening preventive measures aimed at reducing the risk of transmission of WNV trough blood, tissues and organ donation and to implementing further measures for vector control. This article is copyright of The Authors, 2016.

An intra-laboratory cultural and real-time PCR method comparison and evaluation for the detection of subclinical paratuberculosis in dairy herds.

PubMed

Heuvelink, Annet; Hassan, Abdulwahed Ahmed; van Weering, Hilmar; van Engelen, Erik; Bülte, Michael; Akineden, Ömer

2017-05-01

Mycobacterium avium subsp. paratuberculosis (MAP) is a vigorous microorganism which causes incurable chronic enteritis, Johne's disease (JD) in cattle. A target of control programmes for JD is to accurately detect MAP-infected cattle early to reduce disease transmission. The present study evaluated the efficacy of two different cultural procedures and a TaqMan real-time PCR assay for detection of subclinical paratuberculosis in dairy herds. Therefore, sixty-one faecal samples were collected from two Dutch dairy herds (n = 40 and n = 21, respectively) which were known to be MAP-ELISA positive. All individual samples were assessed using two different cultural protocols in two different laboratories. The first cultural protocol (first laboratory) included a decontamination step with 0.75% hexadecylpyridinium chloride (HPC) followed by inoculation on Herrold's egg yolk media (HEYM). The second protocol (second laboratory) comprised of a decontamination step using 4% NaOH and malachite green-oxalic acid followed by inoculation on two media, HEYM and in parallel on modified Löwenstein-Jensen media (mLJ). For the TaqMan real-time PCR assay, all faecal samples were tested in two different laboratories using TaqMan® MAP (Johne's) reagents (Life Technologies). The cultural procedures revealed positive reactions in 1.64% of the samples for cultivation protocol 1 and 6.56 and 8.20% of the samples for cultivation protocol 2, respectively. The results of the TaqMan real-time PCR performed in two different laboratories yielded 13.11 and 19.76% positive reaction. The kappa test showed proportional agreement 0.54 between the mLJ media (second laboratory) and TaqMan® real-time PCR method (second laboratory). In conclusion, the TaqMan real-time PCR could be a strongly useful and efficient assay for the detection of subclinical paratuberculosis in dairy cattle leading to an improvement in the efficiency of MAP control strategies.

Asynchronous Message Service Reference Implementation

NASA Technical Reports Server (NTRS)

Burleigh, Scott C.

2011-01-01

This software provides a library of middleware functions with a simple application programming interface, enabling implementation of distributed applications in conformance with the CCSDS AMS (Consultative Committee for Space Data Systems Asynchronous Message Service) specification. The AMS service, and its protocols, implement an architectural concept under which the modules of mission systems may be designed as if they were to operate in isolation, each one producing and consuming mission information without explicit awareness of which other modules are currently operating. Communication relationships among such modules are self-configuring; this tends to minimize complexity in the development and operations of modular data systems. A system built on this model is a society of generally autonomous, inter-operating modules that may fluctuate freely over time in response to changing mission objectives, modules functional upgrades, and recovery from individual module failure. The purpose of AMS, then, is to reduce mission cost and risk by providing standard, reusable infrastructure for the exchange of information among data system modules in a manner that is simple to use, highly automated, flexible, robust, scalable, and efficient. The implementation is designed to spawn multiple threads of AMS functionality under the control of an AMS application program. These threads enable all members of an AMS-based, distributed application to discover one another in real time, subscribe to messages on specific topics, and to publish messages on specific topics. The query/reply (client/server) communication model is also supported. Message exchange is optionally subject to encryption (to support confidentiality) and authorization. Fault tolerance measures in the discovery protocol minimize the likelihood of overall application failure due to any single operational error anywhere in the system. The multi-threaded design simplifies processing while enabling application nodes to operate at high speeds; linked lists protected by mutex semaphores and condition variables are used for efficient, inter-thread communication. Applications may use a variety of transport protocols underlying AMS itself, including TCP (Transmission Control Protocol), UDP (User Datagram Protocol), and message queues.

TraPy-MAC: Traffic Priority Aware Medium Access Control Protocol for Wireless Body Area Network.

PubMed

Ullah, Fasee; Abdullah, Abdul Hanan; Kaiwartya, Omprakash; Cao, Yue

2017-06-01

Recently, Wireless Body Area Network (WBAN) has witnessed significant attentions in research and product development due to the growing number of sensor-based applications in healthcare domain. Design of efficient and effective Medium Access Control (MAC) protocol is one of the fundamental research themes in WBAN. Static on-demand slot allocation to patient data is the main approach adopted in the design of MAC protocol in literature, without considering the type of patient data specifically the level of severity on patient data. This leads to the degradation of the performance of MAC protocols considering effectiveness and traffic adjustability in realistic medical environments. In this context, this paper proposes a Traffic Priority-Aware MAC (TraPy-MAC) protocol for WBAN. It classifies patient data into emergency and non-emergency categories based on the severity of patient data. The threshold value aided classification considers a number of parameters including type of sensor, body placement location, and data transmission time for allocating dedicated slots patient data. Emergency data are not required to carry out contention and slots are allocated by giving the due importance to threshold value of vital sign data. The contention for slots is made efficient in case of non-emergency data considering threshold value in slot allocation. Moreover, the slot allocation to emergency and non-emergency data are performed parallel resulting in performance gain in channel assignment. Two algorithms namely, Detection of Severity on Vital Sign data (DSVS), and ETS Slots allocation based on the Severity on Vital Sign (ETS-SVS) are developed for calculating threshold value and resolving the conflicts of channel assignment, respectively. Simulations are performed in ns2 and results are compared with the state-of-the-art MAC techniques. Analysis of results attests the benefit of TraPy-MAC in comparison with the state-of-the-art MAC in channel assignment in realistic medical environments.

A software defined RTU multi-protocol automatic adaptation data transmission method

NASA Astrophysics Data System (ADS)

Jin, Huiying; Xu, Xingwu; Wang, Zhanfeng; Ma, Weijun; Li, Sheng; Su, Yong; Pan, Yunpeng

2018-02-01

Remote terminal unit (RTU) is the core device of the monitor system in hydrology and water resources. Different devices often have different communication protocols in the application layer, which results in the difficulty in information analysis and communication networking. Therefore, we introduced the idea of software defined hardware, and abstracted the common feature of mainstream communication protocols of RTU application layer, and proposed a uniformed common protocol model. Then, various communication protocol algorithms of application layer are modularized according to the model. The executable codes of these algorithms are labeled by the virtual functions and stored in the flash chips of embedded CPU to form the protocol stack. According to the configuration commands to initialize the RTU communication systems, it is able to achieve dynamic assembling and loading of various application layer communication protocols of RTU and complete the efficient transport of sensor data from RTU to central station when the data acquisition protocol of sensors and various external communication terminals remain unchanged.

Anti-Noise Bidirectional Quantum Steganography Protocol with Large Payload

NASA Astrophysics Data System (ADS)

Qu, Zhiguo; Chen, Siyi; Ji, Sai; Ma, Songya; Wang, Xiaojun

2018-06-01

An anti-noise bidirectional quantum steganography protocol with large payload protocol is proposed in this paper. In the new protocol, Alice and Bob enable to transmit classical information bits to each other while teleporting secret quantum states covertly. The new protocol introduces the bidirectional quantum remote state preparation into the bidirectional quantum secure communication, not only to expand secret information from classical bits to quantum state, but also extract the phase and amplitude values of secret quantum state for greatly enlarging the capacity of secret information. The new protocol can also achieve better imperceptibility, since the eavesdropper can hardly detect the hidden channel or even obtain effective secret quantum states. Comparing with the previous quantum steganography achievements, due to its unique bidirectional quantum steganography, the new protocol can obtain higher transmission efficiency and better availability. Furthermore, the new algorithm can effectively resist quantum noises through theoretical analysis. Finally, the performance analysis proves the conclusion that the new protocol not only has good imperceptibility, high security, but also large payload.

Anti-Noise Bidirectional Quantum Steganography Protocol with Large Payload

NASA Astrophysics Data System (ADS)

Qu, Zhiguo; Chen, Siyi; Ji, Sai; Ma, Songya; Wang, Xiaojun

2018-03-01

An anti-noise bidirectional quantum steganography protocol with large payload protocol is proposed in this paper. In the new protocol, Alice and Bob enable to transmit classical information bits to each other while teleporting secret quantum states covertly. The new protocol introduces the bidirectional quantum remote state preparation into the bidirectional quantum secure communication, not only to expand secret information from classical bits to quantum state, but also extract the phase and amplitude values of secret quantum state for greatly enlarging the capacity of secret information. The new protocol can also achieve better imperceptibility, since the eavesdropper can hardly detect the hidden channel or even obtain effective secret quantum states. Comparing with the previous quantum steganography achievements, due to its unique bidirectional quantum steganography, the new protocol can obtain higher transmission efficiency and better availability. Furthermore, the new algorithm can effectively resist quantum noises through theoretical analysis. Finally, the performance analysis proves the conclusion that the new protocol not only has good imperceptibility, high security, but also large payload.

Traffic Management for Emergency Vehicle Priority Based on Visual Sensing

PubMed Central

Nellore, Kapileswar; Hancke, Gerhard P.

2016-01-01

Vehicular traffic is endlessly increasing everywhere in the world and can cause terrible traffic congestion at intersections. Most of the traffic lights today feature a fixed green light sequence, therefore the green light sequence is determined without taking the presence of the emergency vehicles into account. Therefore, emergency vehicles such as ambulances, police cars, fire engines, etc. stuck in a traffic jam and delayed in reaching their destination can lead to loss of property and valuable lives. This paper presents an approach to schedule emergency vehicles in traffic. The approach combines the measurement of the distance between the emergency vehicle and an intersection using visual sensing methods, vehicle counting and time sensitive alert transmission within the sensor network. The distance between the emergency vehicle and the intersection is calculated for comparison using Euclidean distance, Manhattan distance and Canberra distance techniques. The experimental results have shown that the Euclidean distance outperforms other distance measurement techniques. Along with visual sensing techniques to collect emergency vehicle information, it is very important to have a Medium Access Control (MAC) protocol to deliver the emergency vehicle information to the Traffic Management Center (TMC) with less delay. Then only the emergency vehicle is quickly served and can reach the destination in time. In this paper, we have also investigated the MAC layer in WSNs to prioritize the emergency vehicle data and to reduce the transmission delay for emergency messages. We have modified the medium access procedure used in standard IEEE 802.11p with PE-MAC protocol, which is a new back off selection and contention window adjustment scheme to achieve low broadcast delay for emergency messages. A VANET model for the UTMS is developed and simulated in NS-2. The performance of the standard IEEE 802.11p and the proposed PE-MAC is analysed in detail. The NS-2 simulation results have shown that the PE-MAC outperforms the IEEE 802.11p in terms of average end-to-end delay, throughput and energy consumption. The performance evaluation results have proven that the proposed PE-MAC prioritizes the emergency vehicle data and delivers the emergency messages to the TMC with less delay compared to the IEEE 802.11p. The transmission delay of the proposed PE-MAC is also compared with the standard IEEE 802.15.4, and Enhanced Back-off Selection scheme for IEEE 802.15.4 protocol [EBSS, an existing protocol to ensure fast transmission of the detected events on the road towards the TMC] and the comparative results have proven the effectiveness of the PE-MAC over them. Furthermore, this research work will provide an insight into the design of an intelligent urban traffic management system for the effective management of emergency vehicles and will help to save lives and property. PMID:27834924

Proposed DoD (Department of Defense) Internet Protocol Standard.

DTIC Science & Technology

1982-07-06

parameters fall into two categories: service quality parameters and service options. Service quality parameters influence the transmission service provided...Corporation 6 July 1982 -7- TM-7172/481/OO o Service Quality Parameters - Precedence : attempts preferential treatment for high importance datagrams...select the transmission quality. IP passes the type of service (TOS) command set for service quality to the SNP where it is mapped into subnetwork

Compact transmission system using single-sideband modulation of light for quantum cryptography.

PubMed

Duraffourg, L; Merolla, J M; Goedgebuer, J P; Mazurenko, Y; Rhodes, W T

2001-09-15

We report a new transmission that can be used for quantum key distribution. The system uses single-sideband-modulated light in an implementation of the BB84 quantum cryptography protocol. The system is formed by two integrated unbalanced Mach-Zehnder interferometers and is based on interference between phase-modulated sidebands in the spectral domain. Experiments show that high interference visibility can be obtained.

Rate of transmission: a major determinant of the cost of clinical mastitis.

PubMed

Down, P M; Green, M J; Hudson, C D

2013-10-01

The aim of this research was to use probabilistic sensitivity analysis to evaluate the relative importance of different components of a model designed to estimate the cost of clinical mastitis (CM). A particular focus was placed on the importance of pathogen transmission relative to other factors, such as milk price or treatment costs. A stochastic Monte Carlo model was developed to simulate a case of CM at the cow level and to calculate the associated costs for 5 defined treatment protocols. The 5 treatment protocols modeled were 3 d of antibiotic intramammary treatment, 5 d of antibiotic intramammary treatment, 3 d of intramammary and systemic antibiotic treatment, 3d of intramammary and systemic antibiotic treatment plus 1 d of nonsteroidal antiinflammatory drug treatment, and 5 d of intramammary and systemic antibiotic treatment. Uniform distributions were used throughout the model to enable investigation of the cost of CM over a spectrum of clinically realistic scenarios without specifying which scenario was more or less likely. A risk of transmission parameter distribution, based on literature values, was included to model the effect of pathogen transmission to uninfected cows, from cows that remained subclinically infected after treatment for CM. Spearman rank correlation coefficients were used to evaluate the relationships between model input values and the estimated cost of CM. Linear regression models were used to explore the effect that changes to specific independent variables had on the cost of CM. Risk of transmission was found to have the strongest association with the cost of CM, followed by bacteriological cure rate, cost of culling, and yield loss. Other factors such as milk price, cost of labor, and cost of medicines were of minimal influence in comparison. The cost of CM was similar for all 5 treatment protocols. The results from this study suggest that, when seeking to minimize the economic impact of CM in dairy herds, great emphasis should be placed on the reduction of pathogen transmission from cows with CM to uninfected cows. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

An evaluation of varying protocols for high-level disinfection of flexible fiberoptic laryngoscopes.

PubMed

Liming, Bryan; Funnell, Ian; Jones, Anthony; Demons, Samandra; Marshall, Kathryn; Harsha, Wayne

2014-11-01

The use of flexible fiberoptic laryngoscopes (FFLs) is ubiquitous in otolaryngology practices. As with any medical device, there exists a small risk for transmission of pathogenic microorganisms between patients, necessitating high-level decontamination between uses. Most of the literature to date has studied channeled scopes such as those used in esophagogastroduodenoscopy and colonoscopy. A recent study of nonchanneled flexible laryngoscopes suggested that current high-level decontamination practices in use at some institutions, including ours, may be overly aggressive. We sought to evaluate and compare the efficacy of varying techniques of high-level disinfection of FFLs. FFLs were used in routine clinical encounters and then disinfected with a variety of techniques. The FFLs were then cultured for bacteria and fungi, and the rates of positive cultures were compared between the techniques and the controls. In this study, we took FFLs following use in routine clinical practice and disinfected them using one of eight decontamination protocols. We compared the bacterial and fungal culture results to positive and negative controls. We demonstrated that each of the eight cleaning protocols was statistically efficacious at removing bacterial contamination. Our results for fungal cultures did not reach statistical significance. Using in vitro inoculation of FFLs, this study demonstrated that quicker and more cost-effective practices are equally efficacious to more time-consuming and expensive techniques with regard to bacterial contamination of FFLs. NA © 2014 The American Laryngological, Rhinological and Otological Society, Inc.

Modified Dynamic Decode-and-Forward Relaying Protocol for Type II Relay in LTE-Advanced and Beyond

PubMed Central

Nam, Sung Sik; Alouini, Mohamed-Slim; Choi, Seyeong

2016-01-01

In this paper, we propose a modified dynamic decode-and-forward (MoDDF) relaying protocol to meet the critical requirements for user equipment (UE) relays in next-generation cellular systems (e.g., LTE-Advanced and beyond). The proposed MoDDF realizes the fast jump-in relaying and the sequential decoding with an application of random codeset to encoding and re-encoding process at the source and the multiple UE relays, respectively. A subframe-by-subframe decoding based on the accumulated (or buffered) messages is employed to achieve energy, information, or mixed combining. Finally, possible early termination of decoding at the end user can lead to the higher spectral efficiency and more energy saving by reducing the frequency of redundant subframe transmission and decoding. These attractive features eliminate the need of directly exchanging control messages between multiple UE relays and the end user, which is an important prerequisite for the practical UE relay deployment. PMID:27898712

Modified Dynamic Decode-and-Forward Relaying Protocol for Type II Relay in LTE-Advanced and Beyond.

PubMed

Nam, Sung Sik; Alouini, Mohamed-Slim; Choi, Seyeong

2016-01-01

In this paper, we propose a modified dynamic decode-and-forward (MoDDF) relaying protocol to meet the critical requirements for user equipment (UE) relays in next-generation cellular systems (e.g., LTE-Advanced and beyond). The proposed MoDDF realizes the fast jump-in relaying and the sequential decoding with an application of random codeset to encoding and re-encoding process at the source and the multiple UE relays, respectively. A subframe-by-subframe decoding based on the accumulated (or buffered) messages is employed to achieve energy, information, or mixed combining. Finally, possible early termination of decoding at the end user can lead to the higher spectral efficiency and more energy saving by reducing the frequency of redundant subframe transmission and decoding. These attractive features eliminate the need of directly exchanging control messages between multiple UE relays and the end user, which is an important prerequisite for the practical UE relay deployment.

Experimental protocol for high-fidelity heralded photon-to-atom quantum state transfer.

PubMed

Kurz, Christoph; Schug, Michael; Eich, Pascal; Huwer, Jan; Müller, Philipp; Eschner, Jürgen

2014-11-21

A quantum network combines the benefits of quantum systems regarding secure information transmission and calculational speed-up by employing quantum coherence and entanglement to store, transmit and process information. A promising platform for implementing such a network are atom-based quantum memories and processors, interconnected by photonic quantum channels. A crucial building block in this scenario is the conversion of quantum states between single photons and single atoms through controlled emission and absorption. Here we present an experimental protocol for photon-to-atom quantum state conversion, whereby the polarization state of an absorbed photon is mapped onto the spin state of a single absorbing atom with >95% fidelity, while successful conversion is heralded by a single emitted photon. Heralded high-fidelity conversion without affecting the converted state is a main experimental challenge, in order to make the transferred information reliably available for further operations. We record >80 s(-1) successful state transfer events out of 18,000 s(-1) repetitions.

Wireless optical network for a home network

NASA Astrophysics Data System (ADS)

Bouchet, Olivier; Porcon, Pascal; Walewski, Joachim W.; Nerreter, Stefan; Langer, Klaus-Dieter; Fernández, Luz; Vucic, Jelena; Kamalakis, Thomas; Ntogari, Georgia; Neokosmidis, Ioannis; Gueutier, Eric

2010-08-01

During the European collaborative project OMEGA, two optical-wireless prototypes have been developed. The first prototype operates in the near-infrared spectral region and features Giga Ethernet connectivity, a simple transceiver architecture due to the use of on-off keying, a multi-sector transceiver, and an ultra-fast switch for sector-to-sector hand over. This full-duplex system, composed by one base station and one module, transmits data on three meters. The second prototype is a visible-light-communications system based on DMT signal processing and an adapted MAC sublayer. Data rates around to 100 Mb/s at the physical layer are achieved. This broadcast system, composed also by one base station and one module, transmits data up to two meters. In this paper we present the adapted optical wireless media-access-control sublayer protocol for visible-light communications. This protocol accommodates link adaptation from 128 Mb/s to 1024 Mb/s with multi-sector coverage, and half-duplex or full-duplex transmission.

Distributed event-triggered consensus tracking of second-order multi-agent systems with a virtual leader

NASA Astrophysics Data System (ADS)

Jie, Cao; Zhi-Hai, Wu; Li, Peng

2016-05-01

This paper investigates the consensus tracking problems of second-order multi-agent systems with a virtual leader via event-triggered control. A novel distributed event-triggered transmission scheme is proposed, which is intermittently examined at constant sampling instants. Only partial neighbor information and local measurements are required for event detection. Then the corresponding event-triggered consensus tracking protocol is presented to guarantee second-order multi-agent systems to achieve consensus tracking. Numerical simulations are given to illustrate the effectiveness of the proposed strategy. Project supported by the National Natural Science Foundation of China (Grant Nos. 61203147, 61374047, and 61403168).

Remote access to medical specialists: home care interactive patient management system

NASA Astrophysics Data System (ADS)

Martin, Peter J.; Draghic, Nicole; Wiesmann, William P.

1999-07-01

Diabetes management involves constant care and rigorous compliance. Glucose control is often difficult to maintain and onset of complications further compound health care needs. Status can be further hampered by geographic isolation from immediate medical infrastructures. The Home Care Interactive Patient Management System is an experimental telemedicine program that could improve chronic illness management through Internet-based applications. The goal of the system is to provide a customized, integrated approach to diabetes management to supplement and coordinate physician protocol while supporting routine patient activity, by supplying a set of customized automated services including health data collection, transmission, analysis and decision support.

Telecare and Social Link Solution for Ambient Assisted Living Using a Robot Companion with Visiophony

NASA Astrophysics Data System (ADS)

Varène, Thibaut; Hillereau, Paul; Simonnet, Thierry

An increasing number of people are in need of help at home (elderly, isolated and/or disabled persons; people with mild cognitive impairment). Several solutions can be considered to maintain a social link while providing tele-care to these people. Many proposals suggest the use of a robot acting as a companion. In this paper we will look at an environment constrained solution, its drawbacks (such as latency) and its advantages (flexibility, integration…). A key design choice is to control the robot using a unified Voice over Internet Protocol (VoIP) solution, while addressing bandwidth limitations, providing good communication quality and reducing transmission latency

An Analysis of Transmission and Storage Gains from Sliding Checksum Methods

DTIC Science & Technology

1998-11-01

analysed a protocol "rsync" for synchronising related files at different ends of a communications channel with a minimum of transmitted data. This report...Sliding Checksum Methods Executive Summary In a previous report we described, modelled and analysed a protocol "rsync" for synchronising related...collaborative writing of documentation and synchronisation of distributed databases in the situation where no one location is aware of the differences

A two-hop based adaptive routing protocol for real-time wireless sensor networks.

PubMed

Rachamalla, Sandhya; Kancherla, Anitha Sheela

2016-01-01

One of the most important and challenging issues in wireless sensor networks (WSNs) is to optimally manage the limited energy of nodes without degrading the routing efficiency. In this paper, we propose an energy-efficient adaptive routing mechanism for WSNs, which saves energy of nodes by removing the much delayed packets without degrading the real-time performance of the used routing protocol. It uses the adaptive transmission power algorithm which is based on the attenuation of the wireless link to improve the energy efficiency. The proposed routing mechanism can be associated with any geographic routing protocol and its performance is evaluated by integrating with the well known two-hop based real-time routing protocol, PATH and the resulting protocol is energy-efficient adaptive routing protocol (EE-ARP). The EE-ARP performs well in terms of energy consumption, deadline miss ratio, packet drop and end-to-end delay.

Running key mapping in a quantum stream cipher by the Yuen 2000 protocol

NASA Astrophysics Data System (ADS)

Shimizu, Tetsuya; Hirota, Osamu; Nagasako, Yuki

2008-03-01

A quantum stream cipher by Yuen 2000 protocol (so-called Y00 protocol or αη scheme) consisting of linear feedback shift register of short key is very attractive in implementing secure 40 Gbits/s optical data transmission, which is expected as a next-generation network. However, a basic model of the Y00 protocol with a very short key needs a careful design against fast correlation attacks as pointed out by Donnet This Brief Report clarifies an effectiveness of irregular mapping between running key and physical signals in the driver for selection of M -ary basis in the transmitter, and gives a design method. Consequently, quantum stream cipher by the Y00 protocol with our mapping has immunity against the proposed fast correlation attacks on a basic model of the Y00 protocol even if the key is very short.

Finite-key security analyses on passive decoy-state QKD protocols with different unstable sources

PubMed Central

Song, Ting-Ting; Qin, Su-Juan; Wen, Qiao-Yan; Wang, Yu-Kun; Jia, Heng-Yue

2015-01-01

In quantum communication, passive decoy-state QKD protocols can eliminate many side channels, but the protocols without any finite-key analyses are not suitable for in practice. The finite-key securities of passive decoy-state (PDS) QKD protocols with two different unstable sources, type-II parametric down-convention (PDC) and phase randomized weak coherent pulses (WCPs), are analyzed in our paper. According to the PDS QKD protocols, we establish an optimizing programming respectively and obtain the lower bounds of finite-key rates. Under some reasonable values of quantum setup parameters, the lower bounds of finite-key rates are simulated. The simulation results show that at different transmission distances, the affections of different fluctuations on key rates are different. Moreover, the PDS QKD protocol with an unstable PDC source can resist more intensity fluctuations and more statistical fluctuation. PMID:26471947

Packet-Based Protocol Efficiency for Aeronautical and Satellite Communications

NASA Technical Reports Server (NTRS)

Carek, David A.

2005-01-01

This paper examines the relation between bit error ratios and the effective link efficiency when transporting data with a packet-based protocol. Relations are developed to quantify the impact of a protocol s packet size and header size relative to the bit error ratio of the underlying link. These relations are examined in the context of radio transmissions that exhibit variable error conditions, such as those used in satellite, aeronautical, and other wireless networks. A comparison of two packet sizing methodologies is presented. From these relations, the true ability of a link to deliver user data, or information, is determined. Relations are developed to calculate the optimal protocol packet size forgiven link error characteristics. These relations could be useful in future research for developing an adaptive protocol layer. They can also be used for sizing protocols in the design of static links, where bit error ratios have small variability.

Development of tellurium oxide and lead-bismuth oxide glasses for mid-wave infra-red transmission optics

NASA Astrophysics Data System (ADS)

Zhou, Beiming; Rapp, Charles F.; Driver, John K.; Myers, Michael J.; Myers, John D.; Goldstein, Jonathan; Utano, Rich; Gupta, Shantanu

2013-03-01

Heavy metal oxide glasses exhibiting high transmission in the Mid-Wave Infra-Red (MWIR) spectrum are often difficult to manufacture in large sizes with optimized physical and optical properties. In this work, we researched and developed improved tellurium-zinc-barium and lead-bismuth-gallium heavy metal oxide glasses for use in the manufacture of fiber optics, optical components and laser gain materials. Two glass families were investigated, one based upon tellurium and another based on lead-bismuth. Glass compositions were optimized for stability and high transmission in the MWIR. Targeted glass specifications included low hydroxyl concentration, extended MWIR transmission window, and high resistance against devitrification upon heating. Work included the processing of high purity raw materials, melting under controlled dry Redox balanced atmosphere, finning, casting and annealing. Batch melts as large as 4 kilograms were sprue cast into aluminum and stainless steel molds or temperature controlled bronze tube with mechanical bait. Small (100g) test melts were typically processed in-situ in a 5%Au°/95%Pt° crucible. Our group manufactured and evaluated over 100 different experimental heavy metal glass compositions during a two year period. A wide range of glass melting, fining, casting techniques and experimental protocols were employed. MWIR glass applications include remote sensing, directional infrared counter measures, detection of explosives and chemical warfare agents, laser detection tracking and ranging, range gated imaging and spectroscopy. Enhanced long range mid-infrared sensor performance is optimized when operating in the atmospheric windows from ~ 2.0 to 2.4μm, ~ 3.5 to 4.3μm and ~ 4.5 to 5.0μm.

Ensuring successful introduction of Wolbachia in natural populations of Aedes aegypti by means of feedback control.

PubMed

Bliman, Pierre-Alexandre; Aronna, M Soledad; Coelho, Flávio C; da Silva, Moacyr A H B

2018-04-01

The control of the spread of dengue fever by introduction of the intracellular parasitic bacterium Wolbachia in populations of the vector Aedes aegypti, is presently one of the most promising tools for eliminating dengue, in the absence of an efficient vaccine. The success of this operation requires locally careful planning to determine the adequate number of individuals carrying the Wolbachia parasite that need to be introduced into the natural population. The introduced mosquitoes are expected to eventually replace the Wolbachia-free population and guarantee permanent protection against the transmission of dengue to human. In this study, we propose and analyze a model describing the fundamental aspects of the competition between mosquitoes carrying Wolbachia and mosquitoes free of the parasite. We then use feedback control techniques to devise an introduction protocol that is proved to guarantee that the population converges to a stable equilibrium where the totality of mosquitoes carry Wolbachia.

CystiSim – An Agent-Based Model for Taenia solium Transmission and Control

PubMed Central

Gabriël, Sarah; Dorny, Pierre; Speybroeck, Niko; Magnussen, Pascal; Torgerson, Paul; Johansen, Maria Vang

2016-01-01

Taenia solium taeniosis/cysticercosis was declared eradicable by the International Task Force for Disease Eradication in 1993, but remains a neglected zoonosis. To assist in the attempt to regionally eliminate this parasite, we developed cystiSim, an agent-based model for T. solium transmission and control. The model was developed in R and available as an R package (http://cran.r-project.org/package=cystiSim). cystiSim was adapted to an observed setting using field data from Tanzania, but adaptable to other settings if necessary. The model description adheres to the Overview, Design concepts, and Details (ODD) protocol and consists of two entities—pigs and humans. Pigs acquire cysticercosis through the environment or by direct contact with a tapeworm carrier's faeces. Humans acquire taeniosis from slaughtered pigs proportional to their infection intensity. The model allows for evaluation of three interventions measures or combinations hereof: treatment of humans, treatment of pigs, and pig vaccination, and allows for customary coverage and efficacy settings. cystiSim is the first agent-based transmission model for T. solium and suggests that control using a strategy consisting of an intervention only targeting the porcine host is possible, but that coverage and efficacy must be high if elimination is the ultimate goal. Good coverage of the intervention is important, but can be compensated for by including an additional intervention targeting the human host. cystiSim shows that the scenarios combining interventions in both hosts, mass drug administration to humans, and vaccination and treatment of pigs, have a high probability of success if coverage of 75% can be maintained over at least a four year period. In comparison with an existing mathematical model for T. solium transmission, cystiSim also includes parasite maturation, host immunity, and environmental contamination. Adding these biological parameters to the model resulted in new insights in the potential effect of intervention measures. PMID:27984581

CystiSim - An Agent-Based Model for Taenia solium Transmission and Control.

PubMed

Braae, Uffe Christian; Devleesschauwer, Brecht; Gabriël, Sarah; Dorny, Pierre; Speybroeck, Niko; Magnussen, Pascal; Torgerson, Paul; Johansen, Maria Vang

2016-12-01

Taenia solium taeniosis/cysticercosis was declared eradicable by the International Task Force for Disease Eradication in 1993, but remains a neglected zoonosis. To assist in the attempt to regionally eliminate this parasite, we developed cystiSim, an agent-based model for T. solium transmission and control. The model was developed in R and available as an R package (http://cran.r-project.org/package=cystiSim). cystiSim was adapted to an observed setting using field data from Tanzania, but adaptable to other settings if necessary. The model description adheres to the Overview, Design concepts, and Details (ODD) protocol and consists of two entities-pigs and humans. Pigs acquire cysticercosis through the environment or by direct contact with a tapeworm carrier's faeces. Humans acquire taeniosis from slaughtered pigs proportional to their infection intensity. The model allows for evaluation of three interventions measures or combinations hereof: treatment of humans, treatment of pigs, and pig vaccination, and allows for customary coverage and efficacy settings. cystiSim is the first agent-based transmission model for T. solium and suggests that control using a strategy consisting of an intervention only targeting the porcine host is possible, but that coverage and efficacy must be high if elimination is the ultimate goal. Good coverage of the intervention is important, but can be compensated for by including an additional intervention targeting the human host. cystiSim shows that the scenarios combining interventions in both hosts, mass drug administration to humans, and vaccination and treatment of pigs, have a high probability of success if coverage of 75% can be maintained over at least a four year period. In comparison with an existing mathematical model for T. solium transmission, cystiSim also includes parasite maturation, host immunity, and environmental contamination. Adding these biological parameters to the model resulted in new insights in the potential effect of intervention measures.

Revisiting Deng et al.'s Multiparty Quantum Secret Sharing Protocol

NASA Astrophysics Data System (ADS)

Hwang, Tzonelih; Hwang, Cheng-Chieh; Yang, Chun-Wei; Li, Chuan-Ming

2011-09-01

The multiparty quantum secret sharing protocol [Deng et al. in Chin. Phys. Lett. 23: 1084-1087, 2006] is revisited in this study. It is found that the performance of Deng et al.'s protocol can be much improved by using the techniques of block-transmission and decoy single photons. As a result, the qubit efficiency is improved 2.4 times and only one classical communication, a public discussion, and two quantum communications between each agent and the secret holder are needed rather than n classical communications, n public discussions, and 3n/2 quantum communications required in the original scheme.

Congestion control and routing over satellite networks

NASA Astrophysics Data System (ADS)

Cao, Jinhua

Satellite networks and transmissions find their application in fields of computer communications, telephone communications, television broadcasting, transportation, space situational awareness systems and so on. This thesis mainly focuses on two networking issues affecting satellite networking: network congestion control and network routing optimization. Congestion, which leads to long queueing delays, packet losses or both, is a networking problem that has drawn the attention of many researchers. The goal of congestion control mechanisms is to ensure high bandwidth utilization while avoiding network congestion by regulating the rate at which traffic sources inject packets into a network. In this thesis, we propose a stable congestion controller using data-driven, safe switching control theory to improve the dynamic performance of satellite Transmission Control Protocol/Active Queue Management (TCP/AQM) networks. First, the stable region of the Proportional-Integral (PI) parameters for a nominal model is explored. Then, a PI controller, whose parameters are adaptively tuned by switching among members of a given candidate set, using observed plant data, is presented and compared with some classical AQM policy examples, such as Random Early Detection (RED) and fixed PI control. A new cost detectable switching law with an interval cost function switching algorithm, which improves the performance and also saves the computational cost, is developed and compared with a law commonly used in the switching control literature. Finite-gain stability of the system is proved. A fuzzy logic PI controller is incorporated as a special candidate to achieve good performance at all nominal points with the available set of candidate controllers. Simulations are presented to validate the theory. An effocient routing algorithm plays a key role in optimizing network resources. In this thesis, we briefly analyze Low Earth Orbit (LEO) satellite networks, review the Cross Entropy (CE) method and then develop a novel on-demand routing system named Cross Entropy Accelerated Ant Routing System (CEAARS) for regular constellation LEO satellite networks. By implementing simulations on an Iridium-like satellite network, we compare the proposed CEAARS algorithm with the two approaches to adaptive routing protocols on the Internet: distance-vector (DV) and link-state (LS), as well as with the original Cross Entropy Ant Routing System (CEARS). DV algorithms are based on distributed Bellman Ford algorithm, and LS algorithms are implementation of Dijkstras single source shortest path. The results show that CEAARS not only remarkably improves the convergence speed of achieving optimal or suboptimal paths, but also reduces the number of overhead ants (management packets).

Towards Reliable and Energy-Efficient Incremental Cooperative Communication for Wireless Body Area Networks.

PubMed

Yousaf, Sidrah; Javaid, Nadeem; Qasim, Umar; Alrajeh, Nabil; Khan, Zahoor Ali; Ahmed, Mansoor

2016-02-24

In this study, we analyse incremental cooperative communication for wireless body area networks (WBANs) with different numbers of relays. Energy efficiency (EE) and the packet error rate (PER) are investigated for different schemes. We propose a new cooperative communication scheme with three-stage relaying and compare it to existing schemes. Our proposed scheme provides reliable communication with less PER at the cost of surplus energy consumption. Analytical expressions for the EE of the proposed three-stage cooperative communication scheme are also derived, taking into account the effect of PER. Later on, the proposed three-stage incremental cooperation is implemented in a network layer protocol; enhanced incremental cooperative critical data transmission in emergencies for static WBANs (EInCo-CEStat). Extensive simulations are conducted to validate the proposed scheme. Results of incremental relay-based cooperative communication protocols are compared to two existing cooperative routing protocols: cooperative critical data transmission in emergencies for static WBANs (Co-CEStat) and InCo-CEStat. It is observed from the simulation results that incremental relay-based cooperation is more energy efficient than the existing conventional cooperation protocol, Co-CEStat. The results also reveal that EInCo-CEStat proves to be more reliable with less PER and higher throughput than both of the counterpart protocols. However, InCo-CEStat has less throughput with a greater stability period and network lifetime. Due to the availability of more redundant links, EInCo-CEStat achieves a reduced packet drop rate at the cost of increased energy consumption.

Towards Reliable and Energy-Efficient Incremental Cooperative Communication for Wireless Body Area Networks

PubMed Central

Yousaf, Sidrah; Javaid, Nadeem; Qasim, Umar; Alrajeh, Nabil; Khan, Zahoor Ali; Ahmed, Mansoor

2016-01-01

In this study, we analyse incremental cooperative communication for wireless body area networks (WBANs) with different numbers of relays. Energy efficiency (EE) and the packet error rate (PER) are investigated for different schemes. We propose a new cooperative communication scheme with three-stage relaying and compare it to existing schemes. Our proposed scheme provides reliable communication with less PER at the cost of surplus energy consumption. Analytical expressions for the EE of the proposed three-stage cooperative communication scheme are also derived, taking into account the effect of PER. Later on, the proposed three-stage incremental cooperation is implemented in a network layer protocol; enhanced incremental cooperative critical data transmission in emergencies for static WBANs (EInCo-CEStat). Extensive simulations are conducted to validate the proposed scheme. Results of incremental relay-based cooperative communication protocols are compared to two existing cooperative routing protocols: cooperative critical data transmission in emergencies for static WBANs (Co-CEStat) and InCo-CEStat. It is observed from the simulation results that incremental relay-based cooperation is more energy efficient than the existing conventional cooperation protocol, Co-CEStat. The results also reveal that EInCo-CEStat proves to be more reliable with less PER and higher throughput than both of the counterpart protocols. However, InCo-CEStat has less throughput with a greater stability period and network lifetime. Due to the availability of more redundant links, EInCo-CEStat achieves a reduced packet drop rate at the cost of increased energy consumption. PMID:26927104

Minimum expected delay-based routing protocol (MEDR) for Delay Tolerant Mobile Sensor Networks.

PubMed

Feng, Yong; Liu, Ming; Wang, Xiaomin; Gong, Haigang

2010-01-01

It is a challenging work to develop efficient routing protocols for Delay Tolerant Mobile Sensor Networks (DTMSNs), which have several unique characteristics such as sensor mobility, intermittent connectivity, energy limit, and delay tolerability. In this paper, we propose a new routing protocol called Minimum Expected Delay-based Routing (MEDR) tailored for DTMSNs. MEDR achieves a good routing performance by finding and using the connected paths formed dynamically by mobile sensors. In MEDR, each sensor maintains two important parameters: Minimum Expected Delay (MED) and its expiration time. According to MED, messages will be delivered to the sensor that has at least a connected path with their hosting nodes, and has the shortest expected delay to communication directly with the sink node. Because of the changing network topology, the path is fragile and volatile, so we use the expiration time of MED to indicate the valid time of the path, and avoid wrong transmissions. Simulation results show that the proposed MEDR achieves a higher message delivery ratio with lower transmission overhead and data delivery delay than other DTMSN routing approaches.

Fast Entanglement Establishment via Local Dynamics for Quantum Repeater Networks

NASA Astrophysics Data System (ADS)

Gyongyosi, Laszlo; Imre, Sandor

Quantum entanglement is a necessity for future quantum communication networks, quantum internet, and long-distance quantum key distribution. The current approaches of entanglement distribution require high-delay entanglement transmission, entanglement swapping to extend the range of entanglement, high-cost entanglement purification, and long-lived quantum memories. We introduce a fundamental protocol for establishing entanglement in quantum communication networks. The proposed scheme does not require entanglement transmission between the nodes, high-cost entanglement swapping, entanglement purification, or long-lived quantum memories. The protocol reliably establishes a maximally entangled system between the remote nodes via dynamics generated by local Hamiltonians. The method eliminates the main drawbacks of current schemes allowing fast entanglement establishment with a minimized delay. Our solution provides a fundamental method for future long-distance quantum key distribution, quantum repeater networks, quantum internet, and quantum-networking protocols. This work was partially supported by the GOP-1.1.1-11-2012-0092 project sponsored by the EU and European Structural Fund, by the Hungarian Scientific Research Fund - OTKA K-112125, and by the COST Action MP1006.

Using quantitative disease dynamics as a tool for guiding response to avian influenza in poultry in the United States of America.

PubMed

Pepin, K M; Spackman, E; Brown, J D; Pabilonia, K L; Garber, L P; Weaver, J T; Kennedy, D A; Patyk, K A; Huyvaert, K P; Miller, R S; Franklin, A B; Pedersen, K; Bogich, T L; Rohani, P; Shriner, S A; Webb, C T; Riley, S

2014-03-01

Wild birds are the primary source of genetic diversity for influenza A viruses that eventually emerge in poultry and humans. Much progress has been made in the descriptive ecology of avian influenza viruses (AIVs), but contributions are less evident from quantitative studies (e.g., those including disease dynamic models). Transmission between host species, individuals and flocks has not been measured with sufficient accuracy to allow robust quantitative evaluation of alternate control protocols. We focused on the United States of America (USA) as a case study for determining the state of our quantitative knowledge of potential AIV emergence processes from wild hosts to poultry. We identified priorities for quantitative research that would build on existing tools for responding to AIV in poultry and concluded that the following knowledge gaps can be addressed with current empirical data: (1) quantification of the spatio-temporal relationships between AIV prevalence in wild hosts and poultry populations, (2) understanding how the structure of different poultry sectors impacts within-flock transmission, (3) determining mechanisms and rates of between-farm spread, and (4) validating current policy-decision tools with data. The modeling studies we recommend will improve our mechanistic understanding of potential AIV transmission patterns in USA poultry, leading to improved measures of accuracy and reduced uncertainty when evaluating alternative control strategies. Copyright © 2013 The Authors. Published by Elsevier B.V. All rights reserved.

West Nile virus: the Italian national transplant network reaction to an alert in the north-eastern region, Italy 2011.

PubMed

Costa, A Nanni; Capobianchi, M R; Ippolito, G; Palù, G; Barzon, L; Piccolo, G; Andreetta, B; Filippetti, M; Fehily, D; Lombardini, L; Grossi, P

2011-10-13

We report four cases of West Nile virus (WNV) transmission following a single multiorgan donation in north-eastern Italy. The transmissions were promptly detected by local transplant centres. The donor had been tested for WNV by nucleic acid amplification test (NAT) prior to transplantation and was negative. There were no detected errors in the nationally implemented WNV safety protocols.

A Study of the Seastar Underwater Acoustic Local Area Network Concept

DTIC Science & Technology

2007-12-01

sense multiple access (CSMA) and multiple access with collision avoidance ( MACA ) are reviewed in [19, 22, 23, 34]. Peripheral nodes using ALOHA and...transmissions until the channel is clear. However, the long propagation time limits the effectiveness of CSMA for acoustic communications. MACA [22] uses... MACA protocol, if no ACK message is received after the transmission is completed, the full packet will be retransmitted until reception is

In-Fiber Magneto-Optic Devices Based on Ultrahigh Verdet Constant Organic Materials and Holey Fibers

DTIC Science & Technology

2009-02-02

protocols and a noise equivalent magnetic field sensitivity of ~ 100 pT/ VHz has been demonstrated. • Magneto-optic properties of magnetite - PMMA composite...nanoparticle - PMMA nanocomposite. We have used both transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM) to...we expect to enhance it in our devices by their proper symmetrization as described above. Passive Poking core ^^ direction Magnetic AA

Preparation and Observation of Thick Biological Samples by Scanning Transmission Electron Tomography.

PubMed

Trépout, Sylvain; Bastin, Philippe; Marco, Sergio

2017-03-12

This report describes a protocol for preparing thick biological specimens for further observation using a scanning transmission electron microscope. It also describes an imaging method for studying the 3D structure of thick biological specimens by scanning transmission electron tomography. The sample preparation protocol is based on conventional methods in which the sample is fixed using chemical agents, treated with a heavy atom salt contrasting agent, dehydrated in a series of ethanol baths, and embedded in resin. The specific imaging conditions for observing thick samples by scanning transmission electron microscopy are then described. Sections of the sample are observed using a through-focus method involving the collection of several images at various focal planes. This enables the recovery of in-focus information at various heights throughout the sample. This particular collection pattern is performed at each tilt angle during tomography data collection. A single image is then generated, merging the in-focus information from all the different focal planes. A classic tilt-series dataset is then generated. The advantage of the method is that the tilt-series alignment and reconstruction can be performed using standard tools. The collection of through-focal images allows the reconstruction of a 3D volume that contains all of the structural details of the sample in focus.

Secure and lightweight network admission and transmission protocol for body sensor networks.

PubMed

He, Daojing; Chen, Chun; Chan, Sammy; Bu, Jiajun; Zhang, Pingxin

2013-05-01

A body sensor network (BSN) is a wireless network of biosensors and a local processing unit, which is commonly referred to as the personal wireless hub (PWH). Personal health information (PHI) is collected by biosensors and delivered to the PWH before it is forwarded to the remote healthcare center for further processing. In a BSN, it is critical to only admit eligible biosensors and PWH into the network. Also, securing the transmission from each biosensor to PWH is essential not only for ensuring safety of PHI delivery, but also for preserving the privacy of PHI. In this paper, we present the design, implementation, and evaluation of a secure network admission and transmission subsystem based on a polynomial-based authentication scheme. The procedures in this subsystem to establish keys for each biosensor are communication efficient and energy efficient. Moreover, based on the observation that an adversary eavesdropping in a BSN faces inevitable channel errors, we propose to exploit the adversary's uncertainty regarding the PHI transmission to update the individual key dynamically and improve key secrecy. In addition to the theoretical analysis that demonstrates the security properties of our system, this paper also reports the experimental results of the proposed protocol on resource-limited sensor platforms, which show the efficiency of our system in practice.

Spatial and temporal variation in biting rates and parasite transmission potentials of onchocerciasis vectors in Ecuador.

PubMed

Vieira, J C; Brackenboro, L; Porter, C H; Basáñez, M-G; Collins, R C

2005-03-01

The influence of spatial and temporal factors on onchocerciasis transmission by Simulium exiguum s.l. and S. quadrivittatum in Ecuador was investigated to help develop sampling protocols for entomological surveillance of ivermectin programmes. Flies were collected in alternate months (November 1995-November 1996) at four sites each in the hyperendemic communities of San Miguel and El Tigre. A fixed-effects analysis of variance was used to explore the influence on vector abundance of locality, site, month and hour. Infectivity rates detected by dissection and PCR assays were compared. Simulium exiguum s.l. predominated at El Tigre (75%) whereas S. quadrivittatum prevailed at San Miguel (62%). Vector abundance was highest on river banks and outside houses. Biting and infection rates peaked from March to July. Hourly activity patterns were bimodal in S. exiguum but unimodal in S. quadrivittatum. Annual transmission potentials (ATP) for both species combined were 385 and 733 third stage larvae/person in San Miguel and El Tigre respectively, with S. exiguum accounting for 80% of the combined ATP at both localities. We recommend protocols that may maximize detection of parasite transmission. Infection rates thus obtained must be linked with vector density estimates to assess meaningfully host exposure as treatment progresses.

47 CFR 51.327 - Notice of network changes: Content of notice.

Code of Federal Regulations, 2012 CFR

2012-10-01

..., but is not limited to, references to technical specifications, protocols, and standards regarding transmission, signaling, routing, and facility assignment as well as references to technical standards that...

47 CFR 51.327 - Notice of network changes: Content of notice.

Code of Federal Regulations, 2014 CFR

2014-10-01

..., but is not limited to, references to technical specifications, protocols, and standards regarding transmission, signaling, routing, and facility assignment as well as references to technical standards that...

47 CFR 51.327 - Notice of network changes: Content of notice.

Code of Federal Regulations, 2013 CFR

2013-10-01

..., but is not limited to, references to technical specifications, protocols, and standards regarding transmission, signaling, routing, and facility assignment as well as references to technical standards that...

A protocol for EBT3 radiochromic film dosimetry using reflection scanning

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

Papaconstadopoulos, Pavlos, E-mail: pavpapac@gmail.com; Hegyi, Gyorgy; Seuntjens, Jan

2014-12-15

Purpose: To evaluate the performance of the EBT3 radiochromic film dosimetry system using reflection measurements and to suggest a calibration protocol for precise and accurate reflection film dosimetry. Methods: A set of 14 Gafchromic EBT3 film pieces were irradiated to various doses ranging from 0 to 8 Gy and subsequently scanned using both the reflection and transmission mode. Scanning resolution varied from 50 to 508 dpi (0.5–0.05 mm/pixel). Both the red and green color channels of scanned images were used to relate the film response to the dose. A sensitivity, uncertainty, and accuracy analysis was performed for all scanning modesmore » and color channels. The total uncertainty, along with the fitting and experimental uncertainty components, was identified and analyzed. A microscope resolution target was used to evaluate possible resolution losses under reflection scanning. The calibration range was optimized for reflection scanning in the low (<2 Gy) and high (>2 Gy) dose regions based on the reported results. Results: Reflection scanning using the red channel exhibited the highest sensitivity among all modes, being up to 150% higher than transmission mode in the red channel for the lowest dose level. Furthermore, there was no apparent loss in resolution between the two modes. However, higher uncertainties and reduced accuracy were observed for the red channel under reflection mode, especially at dose levels higher than 2 Gy. These uncertainties were mainly attributed to saturation effects which were translated in poor fitting results. By restricting the calibration to the 0–2 Gy dose range, the situation is reversed and the red reflection mode was superior to the transmission mode. For higher doses, the green channel in reflection mode presented comparable results to the red transmission. Conclusions: A two-color reflection scanning protocol can be suggested for EBT3 radiochromic film dosimetry using the red channel for doses less than 2 Gy and the green channel for higher doses. The precision and accuracy are significantly improved in the low dose region following such a protocol.« less

Numerical simulation of the optimal two-mode attacks for two-way continuous-variable quantum cryptography in reverse reconciliation

NASA Astrophysics Data System (ADS)

Zhang, Yichen; Li, Zhengyu; Zhao, Yijia; Yu, Song; Guo, Hong

2017-02-01

We analyze the security of the two-way continuous-variable quantum key distribution protocol in reverse reconciliation against general two-mode attacks, which represent all accessible attacks at fixed channel parameters. Rather than against one specific attack model, the expression of secret key rates of the two-way protocol are derived against all accessible attack models. It is found that there is an optimal two-mode attack to minimize the performance of the protocol in terms of both secret key rates and maximal transmission distances. We identify the optimal two-mode attack, give the specific attack model of the optimal two-mode attack and show the performance of the two-way protocol against the optimal two-mode attack. Even under the optimal two-mode attack, the performances of two-way protocol are still better than the corresponding one-way protocol, which shows the advantage of making double use of the quantum channel and the potential of long-distance secure communication using a two-way protocol.

Factors that are associated with the risk of acquiring Plasmodium knowlesi malaria in Sabah, Malaysia: a case-control study protocol.

PubMed

Grigg, M J; William, T; Drakeley, C J; Jelip, J; von Seidlein, L; Barber, B E; Fornace, K M; Anstey, N M; Yeo, T W; Cox, J

2014-08-22

Plasmodium knowlesi has long been present in Malaysia, and is now an emerging cause of zoonotic human malaria. Cases have been confirmed throughout South-East Asia where the ranges of its natural macaque hosts and Anopheles leucosphyrus group vectors overlap. The majority of cases are from Eastern Malaysia, with increasing total public health notifications despite a concurrent reduction in Plasmodium falciparum and P. vivax malaria. The public health implications are concerning given P. knowlesi has the highest risk of severe and fatal disease of all Plasmodium spp in Malaysia. Current patterns of risk and disease vary based on vector type and competence, with individual exposure risks related to forest and forest-edge activities still poorly defined. Clustering of cases has not yet been systematically evaluated despite reports of peri-domestic transmission and known vector competence for human-to-human transmission. A population-based case-control study will be conducted over a 2-year period at two adjacent districts in north-west Sabah, Malaysia. Confirmed malaria cases presenting to the district hospital sites meeting relevant inclusion criteria will be requested to enrol. Three community controls matched to the same village as the case will be selected randomly. Study procedures will include blood sampling and administration of household and individual questionnaires to evaluate potential exposure risks associated with acquisition of P. knowlesi malaria. Secondary outcomes will include differences in exposure variables between P. knowlesi and other Plasmodium spp, risk of severe P. knowlesi malaria, and evaluation of P. knowlesi case clustering. Primary analysis will be per protocol, with adjusted ORs for exposure risks between cases and controls calculated using conditional multiple logistic regression models. This study has been approved by the human research ethics committees of Malaysia, the Menzies School of Health Research, Australia, and the London School of Hygiene and Tropical Medicine, UK. 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.

Studying Dynamic Processes of Nano-sized Objects in Liquid using Scanning Transmission Electron Microscopy.

PubMed

Hermannsdörfer, Justus; de Jonge, Niels

2017-02-05

Samples fully embedded in liquid can be studied at a nanoscale spatial resolution with Scanning Transmission Electron Microscopy (STEM) using a microfluidic chamber assembled in the specimen holder for Transmission Electron Microscopy (TEM) and STEM. The microfluidic system consists of two silicon microchips supporting thin Silicon Nitride (SiN) membrane windows. This article describes the basic steps of sample loading and data acquisition. Most important of all is to ensure that the liquid compartment is correctly assembled, thus providing a thin liquid layer and a vacuum seal. This protocol also includes a number of tests necessary to perform during sample loading in order to ensure correct assembly. Once the sample is loaded in the electron microscope, the liquid thickness needs to be measured. Incorrect assembly may result in a too-thick liquid, while a too-thin liquid may indicate the absence of liquid, such as when a bubble is formed. Finally, the protocol explains how images are taken and how dynamic processes can be studied. A sample containing AuNPs is imaged both in pure water and in saline.

Cut-and-paste restoration of entanglement transmission

NASA Astrophysics Data System (ADS)

Cuevas, Álvaro; Mari, Andrea; De Pasquale, Antonella; Orieux, Adeline; Massaro, Marcello; Sciarrino, Fabio; Mataloni, Paolo; Giovannetti, Vittorio

2017-07-01

The distribution of entangled quantum systems among two or more nodes of a network is a key task at the basis of quantum communication, quantum computation, and quantum cryptography. Unfortunately, the transmission lines used in this procedure can introduce so many perturbations and so much noise in the transmitted signal that they prevent the possibility of restoring quantum correlations in the received messages either by means of encoding optimization or by exploiting local operations and classical communication. In this work we present a procedure which allows one to improve the performance of some of these channels. The mechanism underpinning this result is a protocol which we dub cut and paste, as it consists in extracting and reshuffling the subcomponents of these communication lines, which finally succeed in correcting each other. The proof of this counterintuitive phenomenon, while improving our theoretical understanding of quantum entanglement, also has a direct application in the realization of quantum information networks based on imperfect and highly noisy communication lines. A quantum optics experiment, based on the transmission of single-photon polarization states, is also presented which provides a proof-of-principle test of the proposed protocol.

Studying Dynamic Processes of Nano-sized Objects in Liquid using Scanning Transmission Electron Microscopy

PubMed Central

Hermannsdörfer, Justus; de Jonge, Niels

2017-01-01

Samples fully embedded in liquid can be studied at a nanoscale spatial resolution with Scanning Transmission Electron Microscopy (STEM) using a microfluidic chamber assembled in the specimen holder for Transmission Electron Microscopy (TEM) and STEM. The microfluidic system consists of two silicon microchips supporting thin Silicon Nitride (SiN) membrane windows. This article describes the basic steps of sample loading and data acquisition. Most important of all is to ensure that the liquid compartment is correctly assembled, thus providing a thin liquid layer and a vacuum seal. This protocol also includes a number of tests necessary to perform during sample loading in order to ensure correct assembly. Once the sample is loaded in the electron microscope, the liquid thickness needs to be measured. Incorrect assembly may result in a too-thick liquid, while a too-thin liquid may indicate the absence of liquid, such as when a bubble is formed. Finally, the protocol explains how images are taken and how dynamic processes can be studied. A sample containing AuNPs is imaged both in pure water and in saline. PMID:28190028

A Distributed Transmission Rate Adjustment Algorithm in Heterogeneous CSMA/CA Networks

PubMed Central

Xie, Shuanglong; Low, Kay Soon; Gunawan, Erry

2015-01-01

Distributed transmission rate tuning is important for a wide variety of IEEE 802.15.4 network applications such as industrial network control systems. Such systems often require each node to sustain certain throughput demand in order to guarantee the system performance. It is thus essential to determine a proper transmission rate that can meet the application requirement and compensate for network imperfections (e.g., packet loss). Such a tuning in a heterogeneous network is difficult due to the lack of modeling techniques that can deal with the heterogeneity of the network as well as the network traffic changes. In this paper, a distributed transmission rate tuning algorithm in a heterogeneous IEEE 802.15.4 CSMA/CA network is proposed. Each node uses the results of clear channel assessment (CCA) to estimate the busy channel probability. Then a mathematical framework is developed to estimate the on-going heterogeneous traffics using the busy channel probability at runtime. Finally a distributed algorithm is derived to tune the transmission rate of each node to accurately meet the throughput requirement. The algorithm does not require modifications on IEEE 802.15.4 MAC layer and it has been experimentally implemented and extensively tested using TelosB nodes with the TinyOS protocol stack. The results reveal that the algorithm is accurate and can satisfy the throughput demand. Compared with existing techniques, the algorithm is fully distributed and thus does not require any central coordination. With this property, it is able to adapt to traffic changes and re-adjust the transmission rate to the desired level, which cannot be achieved using the traditional modeling techniques. PMID:25822140

Cardiac Mitochondria l Membrane Stability after Deep Hypothermia using a Xenon Clathrate Cryostasis Protocol – an Electron Microscopy Study

PubMed Central

Sheleg, Sergey; Hixon, Hugh; Cohen, Bruce; Lowry, David; Nedzved, Mikhail

2008-01-01

We investigated a new cryopreservation method using xenon, a clathrate-forming gas, under medium pressure (100psi). The objective of the study was to determine whether this cryostasis protocol could protect cardiac mitochondria at cryogenic temperatures (below 100 degrees Celsius).We analyzed transmission electron microscopy images to obtain information about changes in mitochondrial morphology induced by cryopreservation of the hearts. Our data showed absence of mitochondrial swelling, rupture of inner and outer membranes, and leakage of mitochondrial matrix into the cytoplasm after applying this cryostasis protocol. The electron microscopy results provided the first evidence that a cryostasis protocol using xenon as a clathrate-forming gas under pressure may have protective effects on intracellular membranes. This cryostasis technology may find applications in developing new approaches for long-term cryopreservation protocols. PMID:18787624

The improvement and simulation for LEACH clustering routing protocol

NASA Astrophysics Data System (ADS)

Ji, Ai-guo; Zhao, Jun-xiang

2017-01-01

An energy-balanced unequal multi-hop clustering routing protocol LEACH-EUMC is proposed in this paper. The candidate cluster head nodes are elected firstly, then they compete to be formal cluster head nodes by adding energy and distance factors, finally the date are transferred to sink through multi-hop. The results of simulation show that the improved algorithm is better than LEACH in network lifetime, energy consumption and the amount of data transmission.

Forecast analysis of optical waveguide bus performance

NASA Technical Reports Server (NTRS)

Ledesma, R.; Rourke, M. D.

1979-01-01

Elements to be considered in the design of a data bus include: architecture; data rate; modulation, encoding, detection; power distribution requirements; protocol, work structure; bus reliability, maintainability; interterminal transmission medium; cost; and others specific to application. Fiber- optic data bus considerations for a 32 port transmissive star architecture, are discussed in a tutorial format. General optical-waveguide bus concepts, are reviewed. The electrical and optical performance of a 32 port transmissive star bus, and the effects of temperature on the performance of optical-waveguide buses are examined. A bibliography of pertinent references and the bus receiver test results are included.

The remote diagnosis of malaria using telemedicine or e-mailed images.

PubMed

Murray, Clinton K; Mody, Rupal M; Dooley, David P; Hospenthal, Duane R; Horvath, Lynn L; Moran, Kimberly A; Muntz, Ronald W

2006-12-01

We determined the ability of blinded remote expert microscopy to identify malaria parasites through transmission of malaria smear images via telemedicine and as e-mail attachments. Protocols for malaria smear transmission included: (1) transmission of sender-selected televised smears at various bandwidths (Bw), (2) transmission of remote reader-directed televised smears at various Bw, and (3) transmission of digital photomicrographs as e-mail attachments. Twenty (14%) of 147 sender-selected, and 13 (6%) of 221 reader-directed, images were deemed unreadable by slide readers. The presence or absence of malaria was correctly identified in 98% of the remaining images. Sixty-four (34%) of 190 digital microphotographs were deemed unreadable, while the presence or absence of malaria was correctly identified in 100% of the remaining images. Correct speciation ranged from 45% to 83% across various transmission methods and Bw. The use of telemedicine and e-mail technology shows promise for the remote diagnosis of malaria.

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

Garlapati, Shravan; Kuruganti, Teja; Buehrer, Michael R.

The utilization of state-of-the-art 3G cellular CDMA technologies in a utility owned AMI network results in a large amount of control traffic relative to data traffic, increases the average packet delay and hence are not an appropriate choice for smart grid distribution applications. Like the CDG, we consider a utility owned cellular like CDMA network for smart grid distribution applications and classify the distribution smart grid data as scheduled data and random data. Also, we propose SMAC protocol, which changes its mode of operation based on the type of the data being collected to reduce the data collection latency andmore » control overhead when compared to 3G cellular CDMA2000 MAC. The reduction in the data collection latency and control overhead aids in increasing the number of smart meters served by a base station within the periodic data collection interval, which further reduces the number of base stations needed by a utility or reduces the bandwidth needed to collect data from all the smart meters. The reduction in the number of base stations and/or the reduction in the data transmission bandwidth reduces the CAPital EXpenditure (CAPEX) and OPerational EXpenditure (OPEX) of the AMI network. Finally, the proposed SMAC protocol is analyzed using markov chain, analytical expressions for average throughput and average packet delay are derived, and simulation results are also provided to verify the analysis.« less

The application of the Accelerated Stability Assessment Program (ASAP) to quality by design (QbD) for drug product stability.

PubMed

Waterman, Kenneth Craig

2011-09-01

An isoconversion paradigm, where times in different temperature and humidity-controlled stability chambers are set to provide a fixed degradant level, is shown to compensate for the complex, non-single order kinetics of solid drug products. A humidity-corrected Arrhenius equation provides reliable estimates for temperature and relative humidity effects on degradation rates. A statistical protocol is employed to determine best fits for chemical stability data, which in turn allows for accurate estimations of shelf life (with appropriate confidence intervals) at any storage condition including inside packaging (based on the moisture vapor transmission rate of the packaging and moisture sorption isotherms of the internal components). These methodologies provide both faster results and far better predictions of chemical stability limited shelf life (expiry) than previously possible. Precise shelf-life estimations are generally determined using a 2-week, product-specific protocol. Once the model for a product is developed, it can play a critical role in providing the product understanding necessary for a quality by design (QbD) filing for product approval and enable rational control strategies to assure product stability. Moreover, this Accelerated Stability Assessment Program (ASAP) enables the coupling of product attributes (e.g., moisture content, packaging options) to allow for flexibility in how control strategies are implemented to provide a balance of cost, speed, and other factors while maintaining adequate stability.

Scalable parallel communications

NASA Technical Reports Server (NTRS)

Maly, K.; Khanna, S.; Overstreet, C. M.; Mukkamala, R.; Zubair, M.; Sekhar, Y. S.; Foudriat, E. C.

1992-01-01

Coarse-grain parallelism in networking (that is, the use of multiple protocol processors running replicated software sending over several physical channels) can be used to provide gigabit communications for a single application. Since parallel network performance is highly dependent on real issues such as hardware properties (e.g., memory speeds and cache hit rates), operating system overhead (e.g., interrupt handling), and protocol performance (e.g., effect of timeouts), we have performed detailed simulations studies of both a bus-based multiprocessor workstation node (based on the Sun Galaxy MP multiprocessor) and a distributed-memory parallel computer node (based on the Touchstone DELTA) to evaluate the behavior of coarse-grain parallelism. Our results indicate: (1) coarse-grain parallelism can deliver multiple 100 Mbps with currently available hardware platforms and existing networking protocols (such as Transmission Control Protocol/Internet Protocol (TCP/IP) and parallel Fiber Distributed Data Interface (FDDI) rings); (2) scale-up is near linear in n, the number of protocol processors, and channels (for small n and up to a few hundred Mbps); and (3) since these results are based on existing hardware without specialized devices (except perhaps for some simple modifications of the FDDI boards), this is a low cost solution to providing multiple 100 Mbps on current machines. In addition, from both the performance analysis and the properties of these architectures, we conclude: (1) multiple processors providing identical services and the use of space division multiplexing for the physical channels can provide better reliability than monolithic approaches (it also provides graceful degradation and low-cost load balancing); (2) coarse-grain parallelism supports running several transport protocols in parallel to provide different types of service (for example, one TCP handles small messages for many users, other TCP's running in parallel provide high bandwidth service to a single application); and (3) coarse grain parallelism will be able to incorporate many future improvements from related work (e.g., reduced data movement, fast TCP, fine-grain parallelism) also with near linear speed-ups.

SNMP-SI: A Network Management Tool Based on Slow Intelligence System Approach

NASA Astrophysics Data System (ADS)

Colace, Francesco; de Santo, Massimo; Ferrandino, Salvatore

The last decade has witnessed an intense spread of computer networks that has been further accelerated with the introduction of wireless networks. Simultaneously with, this growth has increased significantly the problems of network management. Especially in small companies, where there is no provision of personnel assigned to these tasks, the management of such networks is often complex and malfunctions can have significant impacts on their businesses. A possible solution is the adoption of Simple Network Management Protocol. Simple Network Management Protocol (SNMP) is a standard protocol used to exchange network management information. It is part of the Transmission Control Protocol/Internet Protocol (TCP/IP) protocol suite. SNMP provides a tool for network administrators to manage network performance, find and solve network problems, and plan for network growth. SNMP has a big disadvantage: its simple design means that the information it deals with is neither detailed nor well organized enough to deal with the expanding modern networking requirements. Over the past years much efforts has been given to improve the lack of Simple Network Management Protocol and new frameworks has been developed: A promising approach involves the use of Ontology. This is the starting point of this paper where a novel approach to the network management based on the use of the Slow Intelligence System methodologies and Ontology based techniques is proposed. Slow Intelligence Systems is a general-purpose systems characterized by being able to improve performance over time through a process involving enumeration, propagation, adaptation, elimination and concentration. Therefore, the proposed approach aims to develop a system able to acquire, according to an SNMP standard, information from the various hosts that are in the managed networks and apply solutions in order to solve problems. To check the feasibility of this model first experimental results in a real scenario are showed.

Experimental evolution in silico: a custom-designed mathematical model for virulence evolution of Bacillus thuringiensis.

PubMed

Strauß, Jakob Friedrich; Crain, Philip; Schulenburg, Hinrich; Telschow, Arndt

2016-08-01

Most mathematical models on the evolution of virulence are based on epidemiological models that assume parasite transmission follows the mass action principle. In experimental evolution, however, mass action is often violated due to controlled infection protocols. This "theory-experiment mismatch" raises the question whether there is a need for new mathematical models to accommodate the particular characteristics of experimental evolution. Here, we explore the experimental evolution model system of Bacillus thuringiensis as a parasite and Caenorhabditis elegans as a host. Recent experimental studies with strict control of parasite transmission revealed that one-sided adaptation of B. thuringiensis with non-evolving hosts selects for intermediate or no virulence, sometimes coupled with parasite extinction. In contrast, host-parasite coevolution selects for high virulence and for hosts with strong resistance against B. thuringiensis. In order to explain the empirical results, we propose a new mathematical model that mimics the basic experimental set-up. The key assumptions are: (i) controlled parasite transmission (no mass action), (ii) discrete host generations, and (iii) context-dependent cost of toxin production. Our model analysis revealed the same basic trends as found in the experiments. Especially, we could show that resistant hosts select for highly virulent bacterial strains. Moreover, we found (i) that the evolved level of virulence is independent of the initial level of virulence, and (ii) that the average amount of bacteria ingested significantly affects the evolution of virulence with fewer bacteria ingested selecting for highly virulent strains. These predictions can be tested in future experiments. This study highlights the usefulness of custom-designed mathematical models in the analysis and interpretation of empirical results from experimental evolution. Copyright © 2016 The Authors. Published by Elsevier GmbH.. All rights reserved.

A prospective cohort study to evaluate peridomestic infection as a determinant of dengue transmission: Protocol

PubMed Central

2012-01-01

Background Vector control programs, which have focused mainly on the patient house and peridomestic areas around dengue cases, have not produced the expected impact on transmission. This project will evaluate the assumption that the endemic/epidemic transmission of dengue begins around peridomestic vicinities of the primary cases. Its objective is to assess the relationship between symptomatic dengue case exposure and peridomestic infection incidence. Methods/Design A prospective cohort study will be conducted (in Tepalcingo and Axochiapan, in the state of Morelos, Mexico), using the state surveillance system for the detection of incident cases. Paired blood specimens will be collected from both the individuals who live with the incident cases and a sample of subjects residing within a 25-meter radius of such cases (exposed cohort), in order to measure dengue-specific antibodies. Other subjects will be selected from areas which have not presented any incident cases within 200 meters, during the two months preceding the sampling (non-exposed cohort). Symptomatic/asymptomatic incident infection will be considered as the dependent variable, exposure to confirmed dengue cases, as the principal variable, and the socio-demographic, environmental and socio-cultural conditions of the subjects, as additional explanatory variables. Discussion Results indicating a high infection rate among the exposed subjects would justify the application of peridomestic control measures and call for an evaluation of alternate causes for insufficient program impact. On the other hand, a low incidence of peridomestic-infected subjects would support the hypothesis that infection occurs outside the domicile, and would thus explain why the vector control measures applied in the past have exerted such a limited impact on cases incidence rates. The results of the present study may therefore serve to reassess site selection for interventions of this type. PMID:22471857

Safety and effectiveness of antiretroviral drugs during pregnancy, delivery and breastfeeding for prevention of mother-to-child transmission of HIV-1: the Kesho Bora Multicentre Collaborative Study rationale, design, and implementation challenges.

PubMed

2011-01-01

To evaluate strategies to reduce HIV-1 transmission through breastfeeding, a multicentre study including a nested randomized controlled trial was implemented in five research sites in West, East and South Africa (The Kesho Bora Study). The aim was to optimize the use of antiretroviral (ARV) drugs during pregnancy, delivery and breastfeeding to prevent mother-to-child transmission of HIV-1 (PMTCT) and to preserve the health of the HIV-1-infected mother. The study included long-term ARV treatment for women with advanced disease, and short-course ARV prophylaxis stopped at delivery for women with early disease. Women with intermediate disease participated in a randomized controlled trial to compare safety and efficacy of triple-ARV prophylaxis prolonged during breastfeeding with short-course ARV prophylaxis stopped at delivery. Between January 2005 and August 2008 a total of 1140 women were enrolled. This paper describes the study design, interventions and protocol amendments introduced to adapt to evolving scientific knowledge, international guidelines and availability of ARV treatment. The paper highlights the successes and challenges during the conduct of the trial. The Kesho Bora Study included one of the few randomized controlled trials to assess safety and efficacy of ARV prophylaxis continued during breastfeeding and the only randomized trial to assess maternal prophylaxis started during pregnancy. The findings have been important for informing international and national guidelines on MTCT prevention in developing countries where, due to poverty, lack of reliable and affordable supply of replacement feed and stigma associated with HIV/AIDS, HIV-infected women have little or no option other than to breastfeed their infants. (ISRCTN71468401). Copyright © 2010 Elsevier Inc. All rights reserved.

CFDP for Interplanetary Overlay Network

NASA Technical Reports Server (NTRS)

Burleigh, Scott C.

2011-01-01

The CCSDS (Consultative Committee for Space Data Systems) File Delivery Protocol for Interplanetary Overlay Network (CFDP-ION) is an implementation of CFDP that uses IO' s DTN (delay tolerant networking) implementation as its UT (unit-data transfer) layer. Because the DTN protocols effect automatic, reliable transmission via multiple relays, CFDP-ION need only satisfy the requirements for Class 1 ("unacknowledged") CFDP. This keeps the implementation small, but without loss of capability. This innovation minimizes processing resources by using zero-copy objects for file data transmission. It runs without modification in VxWorks, Linux, Solaris, and OS/X. As such, this innovation can be used without modification in both flight and ground systems. Integration with DTN enables the CFDP implementation itself to be very simple; therefore, very small. Use of ION infrastructure minimizes consumption of storage and processing resources while maximizing safety.

SMAC: A soft MAC to reduce control overhead and latency in CDMA-based AMI networks

DOE PAGES

Garlapati, Shravan; Kuruganti, Teja; Buehrer, Michael R.; ...

2015-10-26

The utilization of state-of-the-art 3G cellular CDMA technologies in a utility owned AMI network results in a large amount of control traffic relative to data traffic, increases the average packet delay and hence are not an appropriate choice for smart grid distribution applications. Like the CDG, we consider a utility owned cellular like CDMA network for smart grid distribution applications and classify the distribution smart grid data as scheduled data and random data. Also, we propose SMAC protocol, which changes its mode of operation based on the type of the data being collected to reduce the data collection latency andmore » control overhead when compared to 3G cellular CDMA2000 MAC. The reduction in the data collection latency and control overhead aids in increasing the number of smart meters served by a base station within the periodic data collection interval, which further reduces the number of base stations needed by a utility or reduces the bandwidth needed to collect data from all the smart meters. The reduction in the number of base stations and/or the reduction in the data transmission bandwidth reduces the CAPital EXpenditure (CAPEX) and OPerational EXpenditure (OPEX) of the AMI network. Finally, the proposed SMAC protocol is analyzed using markov chain, analytical expressions for average throughput and average packet delay are derived, and simulation results are also provided to verify the analysis.« less

Need low-cost networking? Consider DeviceNet

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

Moss, W.H.

1996-11-01

The drive to reduce production costs and optimize system performance in manufacturing facilities causes many end users to invest in network solutions. Because of distinct differences between the way tasks are performed and the way data are handled for various applications, it is clear than more than one network will be needed in most facilities. What is not clear is which network is most appropriate for a given application. The information layer is the link between automation and information environments via management information systems (MISs) and manufacturing execution systems (MESs) and manufacturing execution systems (MESs). Here the market has chosenmore » a de facto standard in Ethernet, primarily transmission control protocol/internet protocol (TCP/IP) and secondarily manufacturing messaging system (MMS). There is no single standard at the device layer. However, the DeviceNet communication standard has made strides to reach this goal. This protocol eliminates expensive hardwiring and provides improved communication between devices and important device-level diagnostics not easily accessible or available through hardwired I/O interfaces. DeviceNet is a low-cost communications link connecting industrial devices to a network. Many original equipment manufacturers and end users have chosen the DeviceNet platform for several reasons, but most frequently because of four key features: interchangeability; low cost; advanced diagnostics; insert devices under power.« less

A Survey on the Taxonomy of Cluster-Based Routing Protocols for Homogeneous Wireless Sensor Networks

PubMed Central

Naeimi, Soroush; Ghafghazi, Hamidreza; Chow, Chee-Onn; Ishii, Hiroshi

2012-01-01

The past few years have witnessed increased interest among researchers in cluster-based protocols for homogeneous networks because of their better scalability and higher energy efficiency than other routing protocols. Given the limited capabilities of sensor nodes in terms of energy resources, processing and communication range, the cluster-based protocols should be compatible with these constraints in either the setup state or steady data transmission state. With focus on these constraints, we classify routing protocols according to their objectives and methods towards addressing the shortcomings of clustering process on each stage of cluster head selection, cluster formation, data aggregation and data communication. We summarize the techniques and methods used in these categories, while the weakness and strength of each protocol is pointed out in details. Furthermore, taxonomy of the protocols in each phase is given to provide a deeper understanding of current clustering approaches. Ultimately based on the existing research, a summary of the issues and solutions of the attributes and characteristics of clustering approaches and some open research areas in cluster-based routing protocols that can be further pursued are provided. PMID:22969350

A survey on the taxonomy of cluster-based routing protocols for homogeneous wireless sensor networks.

PubMed

Naeimi, Soroush; Ghafghazi, Hamidreza; Chow, Chee-Onn; Ishii, Hiroshi

2012-01-01

The past few years have witnessed increased interest among researchers in cluster-based protocols for homogeneous networks because of their better scalability and higher energy efficiency than other routing protocols. Given the limited capabilities of sensor nodes in terms of energy resources, processing and communication range, the cluster-based protocols should be compatible with these constraints in either the setup state or steady data transmission state. With focus on these constraints, we classify routing protocols according to their objectives and methods towards addressing the shortcomings of clustering process on each stage of cluster head selection, cluster formation, data aggregation and data communication. We summarize the techniques and methods used in these categories, while the weakness and strength of each protocol is pointed out in details. Furthermore, taxonomy of the protocols in each phase is given to provide a deeper understanding of current clustering approaches. Ultimately based on the existing research, a summary of the issues and solutions of the attributes and characteristics of clustering approaches and some open research areas in cluster-based routing protocols that can be further pursued are provided.

Assessing the feasibility of interrupting the transmission of soil-transmitted helminths through mass drug administration: The DeWorm3 cluster randomized trial protocol

PubMed Central

Ajjampur, Sitara S. Rao; Anderson, Roy M.; Bailey, Robin; Gardiner, Iain; Halliday, Katherine E.; Ibikounle, Moudachirou; Kalua, Khumbo; Kang, Gagandeep; Littlewood, D. Timothy J.; Luty, Adrian J. F.; Means, Arianna Rubin; Oswald, William; Pullan, Rachel L.; Sarkar, Rajiv; Schär, Fabian; Szpiro, Adam; Truscott, James E.; Werkman, Marleen; Yard, Elodie; Walson, Judd L.

2018-01-01

Current control strategies for soil-transmitted helminths (STH) emphasize morbidity control through mass drug administration (MDA) targeting preschool- and school-age children, women of childbearing age and adults in certain high-risk occupations such as agricultural laborers or miners. This strategy is effective at reducing morbidity in those treated but, without massive economic development, it is unlikely it will interrupt transmission. MDA will therefore need to continue indefinitely to maintain benefit. Mathematical models suggest that transmission interruption may be achievable through MDA alone, provided that all age groups are targeted with high coverage. The DeWorm3 Project will test the feasibility of interrupting STH transmission using biannual MDA targeting all age groups. Study sites (population ≥80,000) have been identified in Benin, Malawi and India. Each site will be divided into 40 clusters, to be randomized 1:1 to three years of twice-annual community-wide MDA or standard-of-care MDA, typically annual school-based deworming. Community-wide MDA will be delivered door-to-door, while standard-of-care MDA will be delivered according to national guidelines. The primary outcome is transmission interruption of the STH species present at each site, defined as weighted cluster-level prevalence ≤2% by quantitative polymerase chain reaction (qPCR), 24 months after the final round of MDA. Secondary outcomes include the endline prevalence of STH, overall and by species, and the endline prevalence of STH among children under five as an indicator of incident infections. Secondary analyses will identify cluster-level factors associated with transmission interruption. Prevalence will be assessed using qPCR of stool samples collected from a random sample of cluster residents at baseline, six months after the final round of MDA and 24 months post-MDA. A smaller number of individuals in each cluster will be followed with annual sampling to monitor trends in prevalence and reinfection throughout the trial. Trial registration ClinicalTrials.gov NCT03014167 PMID:29346377

Receiver-Assisted Congestion Control to Achieve High Throughput in Lossy Wireless Networks

NASA Astrophysics Data System (ADS)

Shi, Kai; Shu, Yantai; Yang, Oliver; Luo, Jiarong

2010-04-01

Many applications would require fast data transfer in high-speed wireless networks nowadays. However, due to its conservative congestion control algorithm, Transmission Control Protocol (TCP) cannot effectively utilize the network capacity in lossy wireless networks. In this paper, we propose a receiver-assisted congestion control mechanism (RACC) in which the sender performs loss-based control, while the receiver is performing delay-based control. The receiver measures the network bandwidth based on the packet interarrival interval and uses it to compute a congestion window size deemed appropriate for the sender. After receiving the advertised value feedback from the receiver, the sender then uses the additive increase and multiplicative decrease (AIMD) mechanism to compute the correct congestion window size to be used. By integrating the loss-based and the delay-based congestion controls, our mechanism can mitigate the effect of wireless losses, alleviate the timeout effect, and therefore make better use of network bandwidth. Simulation and experiment results in various scenarios show that our mechanism can outperform conventional TCP in high-speed and lossy wireless environments.

Security Issues for Mobile Medical Imaging: A Primer.

PubMed

Choudhri, Asim F; Chatterjee, Arindam R; Javan, Ramin; Radvany, Martin G; Shih, George

2015-10-01

The end-user of mobile device apps in the practice of clinical radiology should be aware of security measures that prevent unauthorized use of the device, including passcode policies, methods for dealing with failed login attempts, network manager-controllable passcode enforcement, and passcode enforcement for the protection of the mobile device itself. Protection of patient data must be in place that complies with the Health Insurance Portability and Accountability Act and U.S. Federal Information Processing Standards. Device security measures for data protection include methods for locally stored data encryption, hardware encryption, and the ability to locally and remotely clear data from the device. As these devices transfer information over both local wireless networks and public cell phone networks, wireless network security protocols, including wired equivalent privacy and Wi-Fi protected access, are important components in the chain of security. Specific virtual private network protocols, Secure Sockets Layer and related protocols (especially in the setting of hypertext transfer protocols), native apps, virtual desktops, and nonmedical commercial off-the-shelf apps require consideration in the transmission of medical data over both private and public networks. Enterprise security and management of both personal and enterprise mobile devices are discussed. Finally, specific standards for hardware and software platform security, including prevention of hardware tampering, protection from malicious software, and application authentication methods, are vital components in establishing a secure platform for the use of mobile devices in the medical field. © RSNA, 2015.

Implementation of a quantum controlled-SWAP gate with photonic circuits

NASA Astrophysics Data System (ADS)

Ono, Takafumi; Okamoto, Ryo; Tanida, Masato; Hofmann, Holger F.; Takeuchi, Shigeki

2017-03-01

Quantum information science addresses how the processing and transmission of information are affected by uniquely quantum mechanical phenomena. Combination of two-qubit gates has been used to realize quantum circuits, however, scalability is becoming a critical problem. The use of three-qubit gates may simplify the structure of quantum circuits dramatically. Among them, the controlled-SWAP (Fredkin) gates are essential since they can be directly applied to important protocols, e.g., error correction, fingerprinting, and optimal cloning. Here we report a realization of the Fredkin gate for photonic qubits. We achieve a fidelity of 0.85 in the computational basis and an output state fidelity of 0.81 for a 3-photon Greenberger-Horne-Zeilinger state. The estimated process fidelity of 0.77 indicates that our Fredkin gate can be applied to various quantum tasks.

Residual energy level based clustering routing protocol for wireless sensor networks

NASA Astrophysics Data System (ADS)

Yuan, Xu; Zhong, Fangming; Chen, Zhikui; Yang, Deli

2015-12-01

The wireless sensor networks, which nodes prone to premature death, with unbalanced energy consumption and a short life time, influenced the promotion and application of this technology in internet of things in agriculture. This paper proposes a clustering routing protocol based on the residual energy level (RELCP). RELCP includes three stages: the selection of cluster head, establishment of cluster and data transmission. RELCP considers the remaining energy level and distance to base station, while election of cluster head nodes and data transmitting. Simulation results demonstrate that the protocol can efficiently balance the energy dissipation of all nodes, and prolong the network lifetime.

Privacy-preserving data aggregation protocols for wireless sensor networks: a survey.

PubMed

Bista, Rabindra; Chang, Jae-Woo

2010-01-01

Many wireless sensor network (WSN) applications require privacy-preserving aggregation of sensor data during transmission from the source nodes to the sink node. In this paper, we explore several existing privacy-preserving data aggregation (PPDA) protocols for WSNs in order to provide some insights on their current status. For this, we evaluate the PPDA protocols on the basis of such metrics as communication and computation costs in order to demonstrate their potential for supporting privacy-preserving data aggregation in WSNs. In addition, based on the existing research, we enumerate some important future research directions in the field of privacy-preserving data aggregation for WSNs.

Performance analysis of the ALOHA protocol with replication in a fading channel for the Mobile Satellite Experiment

NASA Technical Reports Server (NTRS)

Clare, L. P.; Yan, T.-Y.

1985-01-01

The analysis of the ALOHA random access protocol for communications channels with fading is presented. The protocol is modified to send multiple contiguous copies of a message at each transmission attempt. Both pure and slotted ALOHA channels are considered. A general two state model is used for the channel error process to account for the channel fading memory. It is shown that greater throughput and smaller delay may be achieved using repetitions. The model is applied to the analysis of the delay-throughput performance in a fading mobile communications environment. Numerical results are given for NASA's Mobile Satellite Experiment.

Three-party quantum secure direct communication against collective noise

NASA Astrophysics Data System (ADS)

He, Ye-Feng; Ma, Wen-Ping

2017-10-01

Based on logical quantum states, two three-party quantum secure direct communication protocols are proposed, which can realize the exchange of the secret messages between three parties with the help of the measurement correlation property of six-particle entangled states. These two protocols can be immune to the collective-dephasing noise and the collective-rotation noise, respectively; neither of them has information leakage problem. The one-way transmission mode ensures that they can congenitally resist against the Trojan horse attacks and the teleportation attack. Furthermore, these two protocols are secure against other active attacks because of the use of the decoy state technology.

Secret Bit Transmission Using a Random Deal of Cards

DTIC Science & Technology

1990-05-01

conversation between sender and receiver is public and is heard by all. A correct protocol always succeeds in transmitting the secret bit, and the other player...s), who receive the remaining cards and are assumed to have unlimited computing power, gain no information whatsoever about the value of the secret bit...In other words, their probability of correctly guessing the secret is bit exactly the same after listening to a run of the protocol as it was

Achieving the Holevo bound via a bisection decoding protocol

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

Rosati, Matteo; Giovannetti, Vittorio

2016-06-15

We present a new decoding protocol to realize transmission of classical information through a quantum channel at asymptotically maximum capacity, achieving the Holevo bound and thus the optimal communication rate. At variance with previous proposals, our scheme recovers the message bit by bit, making use of a series of “yes-no” measurements, organized in bisection fashion, thus determining which codeword was sent in log{sub 2} N steps, N being the number of codewords.

Local network assessment

NASA Astrophysics Data System (ADS)

Glen, D. V.

1985-04-01

Local networks, related standards activities of the Institute of Electrical and Electronics Engineers the American National Standards Institute and other elements are presented. These elements include: (1) technology choices such as topology, transmission media, and access protocols; (2) descriptions of standards for the 802 local area networks (LAN's); high speed local networks (HSLN's) and military specification local networks; and (3) intra- and internetworking using bridges and gateways with protocols Interconnection (OSI) reference model. The convergence of LAN/PBX technology is also described.

Anonymous broadcasting of classical information with a continuous-variable topological quantum code

NASA Astrophysics Data System (ADS)

Menicucci, Nicolas C.; Baragiola, Ben Q.; Demarie, Tommaso F.; Brennen, Gavin K.

2018-03-01

Broadcasting information anonymously becomes more difficult as surveillance technology improves, but remarkably, quantum protocols exist that enable provably traceless broadcasting. The difficulty is making scalable entangled resource states that are robust to errors. We propose an anonymous broadcasting protocol that uses a continuous-variable surface-code state that can be produced using current technology. High squeezing enables large transmission bandwidth and strong anonymity, and the topological nature of the state enables local error mitigation.

Transmission electron microscopy artifacts in characterization of the nanomaterial-cell interactions.

PubMed

Leung, Yu Hang; Guo, Mu Yao; Ma, Angel P Y; Ng, Alan M C; Djurišić, Aleksandra B; Degger, Natalie; Leung, Frederick C C

2017-07-01

We investigated transmission electron microscopy artifacts obtained using standard sample preparation protocols applied to the investigation of Escherichia coli cells exposed to common nanomaterials, such as TiO 2 , Ag, ZnO, and MgO. While the common protocols for some nanomaterials result only in known issues of nanomaterial-independent generation of anomalous deposits due to fixation and staining, for others, there are reactions between the nanomaterial and chemicals used for post-fixation or staining. Only in the case of TiO 2 do we observe only the known issues of nanomaterial-independent generation of anomalous deposits due to exceptional chemical stability of this material. For the other three nanomaterials, different artifacts are observed. For each of those, we identify causes of the observed problems and suggest alternative sample preparation protocols to avoid artifacts arising from the sample preparation, which is essential for correct interpretation of the obtained images and drawing correct conclusions on cell-nanomaterial interactions. Finally, we propose modified sample preparation and characterization protocols for comprehensive and conclusive investigations of nanomaterial-cell interactions using electron microscopy and for obtaining clear and unambiguous revelation whether the nanomaterials studied penetrate the cells or accumulate at the cell membranes. In only the case of MgO and ZnO, the unambiguous presence of Zn and Mg could be observed inside the cells.

The upgraded HADES trigger and data acquisition system

NASA Astrophysics Data System (ADS)

Michel, J.; Böhmer, M.; Kajetanowicz, M.; Korcyl, G.; Maier, L.; Palka, M.; Stroth, J.; Tarantola, A.; Traxler, M.; Ugur, C.; Yurevich, S.

2011-12-01

The HADES experiment is a High Acceptance Di-Electron Spectrometer located at GSI in Darmstadt, Germany. Recently, its trigger and data acquisition system was upgraded. The main goal was to substantially increase the event rate capability by a factor of up to 20 to reach 100 kHz in light and 20 kHz in heavy ion reaction systems. The total data rate written to storage is about 400 MByte/s in peak. In this context, the complete read-out system was exchanged to FPGA-based platforms using optical communication. For data transport a general-purpose real-time network protocol was developed to meet the strong requirements of the system. In particular, trigger information has to reach all front-end modules with latencies of less than 5 μs through up to 10 intermediate hubs in a star-like network setup. Monitoring and slow control features as well as readout and trigger distribution were joined in a single network protocol made up by three virtual channels with inherent arbitration by priority and a typical switching time of 100 ns. The full DAQ system includes about 550 FPGAs distributed over the complete detector system. For control and monitoring a virtual address space spanning the whole network is provided. Data are merged by the network hubs into data streams and passed on to a server farm using an Ethernet infrastructure. Due to the electromagnetic noise environment, several transmission error detection and correction features were included. In collaboration with groups from experiments of the FAIR accelerator complex, further developments based on the versatile hardware and communication protocol are being pursued.

Near-infrared light-controlled tunable grating based on graphene/elastomer composites

NASA Astrophysics Data System (ADS)

Wang, Fei; Jia, Shuhai; Wang, Yonglin; Tang, Zhenhua

2018-02-01

A near-infrared (nIR) light actuated tunable transmission optical grating based on graphene nanoplatelet (GNP)/polydimethylsiloxane (PDMS) and PDMS is proposed. A simple fabrication protocol is studied that allows integration of the grating with the actuation mechanism; both components are made from soft elastomers, and this ensure the tunability and the light-driven operation of the grating. The resulting grating structure demonstrates continuous period tunability of 2.7% under an actuation power density of 220 mW cm-2 within a period of 3 s and also demonstrates a time-independent characteristic. The proposed infrared activated grating can be developed for wireless remote light splitting in bio/chemical sensing and optical telecommunications applications.

Washing uniforms at home: adherence to hospital policy.

PubMed

Riley, Kate; Laird, Katie; Williams, John

2015-02-20

Infection control is a priority for all hospitals to reduce the spread of healthcare-associated infections (HCAIs). Textiles especially uniforms, are a possible route of HCAI transmission. There are protocols to ensure hospital laundry services meet accepted standards, however healthcare uniforms are laundered by staff at home and variations in practice occur. A questionnaire was used to conduct a service evaluation at four hospitals in different NHS trusts to determine how closely healthcare staff followed hospital guidelines on laundering and aftercare of uniforms at home. Responses showed that not all staff followed these guidelines; 44% of staff washed their uniforms below the recommended temperature of 60°C, which presents a potential route for cross-contamination and infection.

Finite-size analysis of continuous-variable measurement-device-independent quantum key distribution

NASA Astrophysics Data System (ADS)

Zhang, Xueying; Zhang, Yichen; Zhao, Yijia; Wang, Xiangyu; Yu, Song; Guo, Hong

2017-10-01

We study the impact of the finite-size effect on the continuous-variable measurement-device-independent quantum key distribution (CV-MDI QKD) protocol, mainly considering the finite-size effect on the parameter estimation procedure. The central-limit theorem and maximum likelihood estimation theorem are used to estimate the parameters. We also analyze the relationship between the number of exchanged signals and the optimal modulation variance in the protocol. It is proved that when Charlie's position is close to Bob, the CV-MDI QKD protocol has the farthest transmission distance in the finite-size scenario. Finally, we discuss the impact of finite-size effects related to the practical detection in the CV-MDI QKD protocol. The overall results indicate that the finite-size effect has a great influence on the secret-key rate of the CV-MDI QKD protocol and should not be ignored.

Design of a novel telerehabilitation system with a force-sensing mechanism.

PubMed

Zhang, Songyuan; Guo, Shuxiang; Gao, Baofeng; Hirata, Hideyuki; Ishihara, Hidenori

2015-05-19

Many stroke patients are expected to rehabilitate at home, which limits their access to proper rehabilitation equipment, treatment, or assessment by therapists. We have developed a novel telerehabilitation system that incorporates a human-upper-limb-like device and an exoskeleton device. The system is designed to provide the feeling of real therapist-patient contact via telerehabilitation. We applied the principle of a series elastic actuator to both the master and slave devices. On the master side, the therapist can operate the device in a rehabilitation center. When performing passive training, the master device can detect the therapist's motion while controlling the deflection of elastic elements to near-zero, and the patient can receive the motion via the exoskeleton device. When performing active training, the design of the force-sensing mechanism in the master device can detect the assisting force added by the therapist. The force-sensing mechanism also allows force detection with an angle sensor. Patients' safety is guaranteed by monitoring the motor's current from the exoskeleton device. To compensate for any possible time delay or data loss, a torque-limiter mechanism was also designed in the exoskeleton device for patients' safety. Finally, we successfully performed a system performance test for passive training with transmission control protocol/internet protocol communication.

Design of a Novel Telerehabilitation System with a Force-Sensing Mechanism

PubMed Central

Zhang, Songyuan; Guo, Shuxiang; Gao, Baofeng; Hirata, Hideyuki; Ishihara, Hidenori

2015-01-01

Many stroke patients are expected to rehabilitate at home, which limits their access to proper rehabilitation equipment, treatment, or assessment by therapists. We have developed a novel telerehabilitation system that incorporates a human-upper-limb-like device and an exoskeleton device. The system is designed to provide the feeling of real therapist–patient contact via telerehabilitation. We applied the principle of a series elastic actuator to both the master and slave devices. On the master side, the therapist can operate the device in a rehabilitation center. When performing passive training, the master device can detect the therapist’s motion while controlling the deflection of elastic elements to near-zero, and the patient can receive the motion via the exoskeleton device. When performing active training, the design of the force-sensing mechanism in the master device can detect the assisting force added by the therapist. The force-sensing mechanism also allows force detection with an angle sensor. Patients’ safety is guaranteed by monitoring the motor’s current from the exoskeleton device. To compensate for any possible time delay or data loss, a torque-limiter mechanism was also designed in the exoskeleton device for patients’ safety. Finally, we successfully performed a system performance test for passive training with transmission control protocol/internet protocol communication. PMID:25996511

Protocol Processing for 100 Gbit/s and Beyond - A Soft Real-Time Approach in Hardware and Software

NASA Astrophysics Data System (ADS)

Büchner, Steffen; Lopacinski, Lukasz; Kraemer, Rolf; Nolte, Jörg

2017-09-01

100 Gbit/s wireless communication protocol processing stresses all parts of a communication system until the outermost. The efficient use of upcoming 100 Gbit/s and beyond transmission technology requires the rethinking of the way protocols are processed by the communication endpoints. This paper summarizes the achievements of the project End2End100. We will present a comprehensive soft real-time stream processing approach that allows the protocol designer to develop, analyze, and plan scalable protocols for ultra high data rates of 100 Gbit/s and beyond. Furthermore, we will present an ultra-low power, adaptable, and massively parallelized FEC (Forward Error Correction) scheme that detects and corrects bit errors at line rate with an energy consumption between 1 pJ/bit and 13 pJ/bit. The evaluation results discussed in this publication show that our comprehensive approach allows end-to-end communication with a very low protocol processing overhead.

Efficient simultaneous dense coding and teleportation with two-photon four-qubit cluster states

NASA Astrophysics Data System (ADS)

Zhang, Cai; Situ, Haozhen; Li, Qin; He, Guang Ping

2016-08-01

We firstly propose a simultaneous dense coding protocol with two-photon four-qubit cluster states in which two receivers can simultaneously get their respective classical information sent by a sender. Because each photon has two degrees of freedom, the protocol will achieve a high transmittance. The security of the simultaneous dense coding protocol has also been analyzed. Secondly, we investigate how to simultaneously teleport two different quantum states with polarization and path degree of freedom using cluster states to two receivers, respectively, and discuss its security. The preparation and transmission of two-photon four-qubit cluster states is less difficult than that of four-photon entangled states, and it has been experimentally generated with nearly perfect fidelity and high generation rate. Thus, our protocols are feasible with current quantum techniques.

Cutaneous leishmaniasis vector control perspectives using lambdacyhalothrin residual house spraying in El Ingenio, Miranda State, Venezuela.

PubMed

Feliciangeli, M Dora; Mazzarri, Milena B; Campbell-Lendrum, Diarmid; Maroli, Michele; Maingon, Rhaiza

2003-01-01

An indoor vector control trial was carried out between December 1996 and February 1997, with the aim of reducing the population densities of Lutzomyia ovallesi, the proven vector of cutaneous leishmaniasis (CL) in El Ingenio, Miranda State, Venezuela. Houses were matched according to their structure ("bahareque" [mud and straw], concrete, and wood) and randomly assigned to a control group (n = 19) or a treated group (n = 20) that was sprayed with 25 mg/m(2) of lambdacyhalothrin. This dose was selected on the basis of a laboratory susceptibility test of Lu. ovallesi to pyrethroids. Sandfly abundance was measured using CDC light traps 7-79 d post-intervention, by which time the sandfly population in control houses had declined to very low levels, at what was the end of the transmission season. Catches of total females, fed females, and males were significantly lower in sprayed than in control houses immediately after treatment. Catches of total females and males in sprayed houses recovered, reaching the level of control houses after 7 and 11 weeks, respectively. Bioassays following WHO protocols using contact cones on a sandfly laboratory colony showed a short residual effect of the insecticide explaining these results. In contrast, there was no tendency for catches of fed females in the sprayed houses to recover during the course of the trial. Previous studies of adult population dynamics showed a short season of high abundance. Combined with these results, we believe that 2 indoor sprayings with lambdacyhalothrin, the first at the beginning of November and the second at the beginning of January, would considerably reduce the Lu. ovallesi population, and control CL transmission in this and other foci where this sandfly is considered to be the main vector.

Human prion diseases: surgical lessons learned from iatrogenic prion transmission.

PubMed

Bonda, David J; Manjila, Sunil; Mehndiratta, Prachi; Khan, Fahd; Miller, Benjamin R; Onwuzulike, Kaine; Puoti, Gianfranco; Cohen, Mark L; Schonberger, Lawrence B; Cali, Ignazio

2016-07-01

The human prion diseases, or transmissible spongiform encephalopathies, have captivated our imaginations since their discovery in the Fore linguistic group in Papua New Guinea in the 1950s. The mysterious and poorly understood "infectious protein" has become somewhat of a household name in many regions across the globe. From bovine spongiform encephalopathy (BSE), commonly identified as mad cow disease, to endocannibalism, media outlets have capitalized on these devastatingly fatal neurological conditions. Interestingly, since their discovery, there have been more than 492 incidents of iatrogenic transmission of prion diseases, largely resulting from prion-contaminated growth hormone and dura mater grafts. Although fewer than 9 cases of probable iatrogenic neurosurgical cases of Creutzfeldt-Jakob disease (CJD) have been reported worldwide, the likelihood of some missed cases and the potential for prion transmission by neurosurgery create considerable concern. Laboratory studies indicate that standard decontamination and sterilization procedures may be insufficient to completely remove infectivity from prion-contaminated instruments. In this unfortunate event, the instruments may transmit the prion disease to others. Much caution therefore should be taken in the absence of strong evidence against the presence of a prion disease in a neurosurgical patient. While the Centers for Disease Control and Prevention (CDC) and World Health Organization (WHO) have devised risk assessment and decontamination protocols for the prevention of iatrogenic transmission of the prion diseases, incidents of possible exposure to prions have unfortunately occurred in the United States. In this article, the authors outline the historical discoveries that led from kuru to the identification and isolation of the pathological prion proteins in addition to providing a brief description of human prion diseases and iatrogenic forms of CJD, a brief history of prion disease nosocomial transmission, and a summary of the CDC and WHO guidelines for prevention of prion disease transmission and decontamination of prion-contaminated neurosurgical instruments.

Human prion diseases: surgical lessons learned from iatrogenic prion transmission

PubMed Central

Bonda, David J.; Manjila, Sunil; Mehndiratta, Prachi; Khan, Fahd; Miller, Benjamin R.; Onwuzulike, Kaine; Puoti, Gianfranco; Cohen, Mark L.; Schonberger, Lawrence B.; Cali, Ignazio

2016-01-01

The human prion diseases, or transmissible spongiform encephalopathies, have captivated our imaginations since their discovery in the Fore linguistic group in Papua New Guinea in the 1950s. The mysterious and poorly understood “infectious protein” has become somewhat of a household name in many regions across the globe. From bovine spongiform encephalopathy (BSE), commonly identified as mad cow disease, to endocannibalism, media outlets have capitalized on these devastatingly fatal neurological conditions. Interestingly, since their discovery, there have been more than 492 incidents of iatrogenic transmission of prion diseases, largely resulting from prion-contaminated growth hormone and dura mater grafts. Although fewer than 9 cases of probable iatrogenic neurosurgical cases of Creutzfeldt-Jakob disease (CJD) have been reported worldwide, the likelihood of some missed cases and the potential for prion transmission by neurosurgery create considerable concern. Laboratory studies indicate that standard decontamination and sterilization procedures may be insufficient to completely remove infectivity from prion-contaminated instruments. In this unfortunate event, the instruments may transmit the prion disease to others. Much caution therefore should be taken in the absence of strong evidence against the presence of a prion disease in a neurosurgical patient. While the Centers for Disease Control and Prevention (CDC) and World Health Organization (WHO) have devised risk assessment and decontamination protocols for the prevention of iatrogenic transmission of the prion diseases, incidents of possible exposure to prions have unfortunately occurred in the United States. In this article, the authors outline the historical discoveries that led from kuru to the identification and isolation of the pathological prion proteins in addition to providing a brief description of human prion diseases and iatrogenic forms of CJD, a brief history of prion disease nosocomial transmission, and a summary of the CDC and WHO guidelines for prevention of prion disease transmission and decontamination of prion-contaminated neurosurgical instruments. PMID:27364252

Lethal and Pre-Lethal Effects of a Fungal Biopesticide Contribute to Substantial and Rapid Control of Malaria Vectors

PubMed Central

Blanford, Simon; Shi, Wangpeng; Christian, Riann; Marden, James H.; Koekemoer, Lizette L.; Brooke, Basil D.; Coetzee, Maureen; Read, Andrew F.; Thomas, Matthew B.

2011-01-01

Rapidly emerging insecticide resistance is creating an urgent need for new active ingredients to control the adult mosquitoes that vector malaria. Biopesticides based on the spores of entomopathogenic fungi have shown considerable promise by causing very substantial mortality within 7–14 days of exposure. This mortality will generate excellent malaria control if there is a high likelihood that mosquitoes contact fungi early in their adult lives. However, where contact rates are lower, as might result from poor pesticide coverage, some mosquitoes will contact fungi one or more feeding cycles after they acquire malaria, and so risk transmitting malaria before the fungus kills them. Critics have argued that ‘slow acting’ fungal biopesticides are, therefore, incapable of delivering malaria control in real-world contexts. Here, utilizing standard WHO laboratory protocols, we demonstrate effective action of a biopesticide much faster than previously reported. Specifically, we show that transient exposure to clay tiles sprayed with a candidate biopesticide comprising spores of a natural isolate of Beauveria bassiana, could reduce malaria transmission potential to zero within a feeding cycle. The effect resulted from a combination of high mortality and rapid fungal-induced reduction in feeding and flight capacity. Additionally, multiple insecticide-resistant lines from three key African malaria vector species were completely susceptible to fungus. Thus, fungal biopesticides can block transmission on a par with chemical insecticides, and can achieve this where chemical insecticides have little impact. These results support broadening the current vector control paradigm beyond fast-acting chemical toxins. PMID:21897846

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 game theory-based obstacle avoidance routing protocol for wireless sensor networks.

PubMed

Guan, Xin; Wu, Huayang; Bi, Shujun

2011-01-01

The obstacle avoidance problem in geographic forwarding is an important issue for location-based routing in wireless sensor networks. The presence of an obstacle leads to several geographic routing problems such as excessive energy consumption and data congestion. Obstacles are hard to avoid in realistic environments. To bypass obstacles, most routing protocols tend to forward packets along the obstacle boundaries. This leads to a situation where the nodes at the boundaries exhaust their energy rapidly and the obstacle area is diffused. In this paper, we introduce a novel routing algorithm to solve the obstacle problem in wireless sensor networks based on a game-theory model. Our algorithm forms a concave region that cannot forward packets to achieve the aim of improving the transmission success rate and decreasing packet transmission delays. We consider the residual energy, out-degree and forwarding angle to determine the forwarding probability and payoff function of forwarding candidates. This achieves the aim of load balance and reduces network energy consumption. Simulation results show that based on the average delivery delay, energy consumption and packet delivery ratio performances our protocol is superior to other traditional schemes.

Obtaining 3D Chemical Maps by Energy Filtered Transmission Electron Microscopy Tomography.

PubMed

Roiban, Lucian; Sorbier, Loïc; Hirlimann, Charles; Ersen, Ovidiu

2018-06-09

Energy filtered transmission electron microscopy tomography (EFTEM tomography) can provide three-dimensional (3D) chemical maps of materials at a nanometric scale. EFTEM tomography can separate chemical elements that are very difficult to distinguish using other imaging techniques. The experimental protocol described here shows how to create 3D chemical maps to understand the chemical distribution and morphology of a material. Sample preparation steps for data segmentation are presented. This protocol permits the 3D distribution analysis of chemical elements in a nanometric sample. However, it should be noted that currently, the 3D chemical maps can only be generated for samples that are not beam sensitive, since the recording of filtered images requires long exposure times to an intense electron beam. The protocol was applied to quantify the chemical distribution of the components of two different heterogeneous catalyst supports. In the first study, the chemical distribution of aluminum and titanium in titania-alumina supports was analyzed. The samples were prepared using the swing-pH method. In the second, the chemical distribution of aluminum and silicon in silica-alumina supports that were prepared using the sol-powder and mechanical mixture methods was examined.

Methicillin-resistant Staphylococcus aureus transmission and infections in a neonatal intensive care unit despite active surveillance cultures and decolonization: challenges for infection prevention.

PubMed

Popoola, Victor O; Budd, Alicia; Wittig, Sara M; Ross, Tracy; Aucott, Susan W; Perl, Trish M; Carroll, Karen C; Milstone, Aaron M

2014-04-01

To characterize the epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) transmission and infections in a level IIIC neonatal intensive care unit (NICU) and identify barriers to MRSA control. Retrospective cohort study in a university-affiliated NICU with an MRSA control program including weekly nares cultures of all neonates and admission nares cultures for neonates transferred from other hospitals or admitted from home. Medical records were reviewed to identify neonates with NICU-acquired MRSA colonization or infection between April 2007 and December 2011. Compliance with hand hygiene and an MRSA decolonization protocol were monitored. Relatedness of MRSA strains were assessed using pulsed-field gel electrophoresis (PFGE). Of 3,536 neonates, 74 (2.0%) had a culture grow MRSA, including 62 neonates with NICU-acquired MRSA. Nineteen of 74 neonates (26%) had an MRSA infection, including 8 who became infected before they were identified as MRSA colonized, and 11 of 66 colonized neonates (17%) developed a subsequent infection. Of the 37 neonates that underwent decolonization, 6 (16%) developed a subsequent infection, and 7 of 14 (50%) that remained in the NICU for 21 days or more became recolonized with MRSA. Using PFGE, there were 14 different strain types identified, with USA300 being the most common (31%). Current strategies to prevent infections-including active identification and decolonization of MRSA-colonized neonates-are inadequate because infants develop infections before being identified as colonized or after attempted decolonization. Future prevention efforts would benefit from improving detection of MRSA colonization, optimizing decolonization regimens, and identifying and interrupting reservoirs of transmission.

Assessing the effectiveness of household-level focal mass drug administration and community-wide mass drug administration for reducing malaria parasite infection prevalence and incidence in Southern Province, Zambia: study protocol for a community randomized controlled trial.

PubMed

Eisele, Thomas P; Silumbe, Kafula; Finn, Timothy; Chalwe, Victor; Kamuliwo, Mukalwa; Hamainza, Busiku; Moonga, Hawela; Bennett, Adam; Yukich, Josh; Keating, Joseph; Steketee, Richard W; Miller, John M

2015-08-13

Mass drug administration (MDA) and focal MDA (fMDA) using dihydroartemisinin plus piperaquine (DHAp), represent two strategies to maximize the use of existing information to achieve greater clearance of human infection and reduce the parasite reservoir, and provide longer chemoprophylactic protection against new infections. The primary aim of this study is to quantify the relative effectiveness of MDA and fMDA with DHAp against no mass treatment (standard of care) for reducing Plasmodium falciparum prevalence and incidence. The study will be conducted along Lake Kariba in Southern Province, Zambia; an area of low to moderate malaria transmission and high coverage of vector control. A community randomized controlled trial (CRCT) of 60 health facility catchment areas (HFCAs) will be used to evaluate the impact of two rounds of MDA and fMDA interventions, relative to a control of no mass treatment, stratified by high and low transmission. Community residents in MDA HFCAs will be treated with DHAp at the end of the dry season (round one: November to December 2014) and the beginning of the rainy season (round two: February to March 2015). Community residents in fMDA HFCAs will be tested during the same two rounds for malaria parasites with a rapid diagnostic test; all positive individuals and all individuals living in their household will be treated with DHAp. Primary outcomes include malaria parasite prevalence (n = 5,640 children aged one month to under five-years-old), as measured by pre- and post-surveys, and malaria parasite infection incidence (n = 2,250 person-years among individuals aged three months and older), as measured by a monthly longitudinal cohort. The study is powered to detect approximately a 50 % relative reduction in these outcomes between each intervention group versus the control. Strengths of this trial include: a robust study design (CRCT); cross-sectional parasite surveys as well as a longitudinal cohort; and stratification of high and low transmission areas. Primary limitations include: statistical power to detect only a 50 % reduction in primary outcomes within high and low transmission strata; potential for contamination; and potential for misclassification of exposure. Identifier: Clinicaltrials.gov: NCT02329301 . Registration date: 30 December 2014.

UTC Time Transfer for High Frequency Trading Using IS-95 CDMA Base Station Transmissions and IEEE-1588 Precision Time Protocol

DTIC Science & Technology

2010-11-01

CDMA base stations are each synchronized by GPS receivers, they provide an indirect link to GPS system time and UTC time . The major stock...antenna synchronizes the Local Area Network (LAN) to within 10 microseconds of UTC using the IEEE-1588 Precision Time Protocol (PTP). This is an...activities. Understanding and measuring latency on the LAN is key to the success of HFTs. Without precise time synchronization below 1 millisecond

GAPR2: A DTN Routing Protocol for Communications in Challenged, Degraded, and Denied Environments

DTIC Science & Technology

2015-09-01

Transmission Speed Vs. Latency Figure 4.7: Helsinki Simulation Set 2, High Network Load and Small Buffers Analysis of Delivery Ratio in Helsinki Simulation...ipnsig.org/. [17] MANET routing, class notes for CS4554: Network modeling and analysis . 119 [18] S. Basagni et al. Mobile ad hoc networking . John...Wiley & Sons, 2004. [19] E. Royer et al. A review of current routing protocols for ad hoc mobile wireless networks . Personal Communications, IEEE, 6(2

Design and Analysis of Secure Routing Protocol for Wireless Sensor Networks

NASA Astrophysics Data System (ADS)

Wang, Jiong; Zhang, Hua

2017-09-01

In recent years, with the development of science and technology and the progress of the times, China's wireless network technology has become increasingly prosperous and it plays an important role in social production and life. In this context, in order to further to enhance the stability of wireless network data transmission and security enhancements, the staff need to focus on routing security and carry out related work. Based on this, this paper analyzes the design of wireless sensor based on secure routing protocol.

Hybrid Packet-Pheromone-Based Probabilistic Routing for Mobile Ad Hoc Networks

NASA Astrophysics Data System (ADS)

Kashkouli Nejad, Keyvan; Shawish, Ahmed; Jiang, Xiaohong; Horiguchi, Susumu

Ad-Hoc networks are collections of mobile nodes communicating using wireless media without any fixed infrastructure. Minimal configuration and quick deployment make Ad-Hoc networks suitable for emergency situations like natural disasters or military conflicts. The current Ad-Hoc networks can only support either high mobility or high transmission rate at a time because they employ static approaches in their routing schemes. However, due to the continuous expansion of the Ad-Hoc network size, node-mobility and transmission rate, the development of new adaptive and dynamic routing schemes has become crucial. In this paper we propose a new routing scheme to support high transmission rates and high node-mobility simultaneously in a big Ad-Hoc network, by combining a new proposed packet-pheromone-based approach with the Hint Based Probabilistic Protocol (HBPP) for congestion avoidance with dynamic path selection in packet forwarding process. Because of using the available feedback information, the proposed algorithm does not introduce any additional overhead. The extensive simulation-based analysis conducted in this paper indicates that the proposed algorithm offers small packet-latency and achieves a significantly higher delivery probability in comparison with the available Hint-Based Probabilistic Protocol (HBPP).

Space Link Extension Protocol Emulation for High-Throughput, High-Latency Network Connections

NASA Technical Reports Server (NTRS)

Tchorowski, Nicole; Murawski, Robert

2014-01-01

New space missions require higher data rates and new protocols to meet these requirements. These high data rate space communication links push the limitations of not only the space communication links, but of the ground communication networks and protocols which forward user data to remote ground stations (GS) for transmission. The Consultative Committee for Space Data Systems, (CCSDS) Space Link Extension (SLE) standard protocol is one protocol that has been proposed for use by the NASA Space Network (SN) Ground Segment Sustainment (SGSS) program. New protocol implementations must be carefully tested to ensure that they provide the required functionality, especially because of the remote nature of spacecraft. The SLE protocol standard has been tested in the NASA Glenn Research Center's SCENIC Emulation Lab in order to observe its operation under realistic network delay conditions. More specifically, the delay between then NASA Integrated Services Network (NISN) and spacecraft has been emulated. The round trip time (RTT) delay for the continental NISN network has been shown to be up to 120ms; as such the SLE protocol was tested with network delays ranging from 0ms to 200ms. Both a base network condition and an SLE connection were tested with these RTT delays, and the reaction of both network tests to the delay conditions were recorded. Throughput for both of these links was set at 1.2Gbps. The results will show that, in the presence of realistic network delay, the SLE link throughput is significantly reduced while the base network throughput however remained at the 1.2Gbps specification. The decrease in SLE throughput has been attributed to the implementation's use of blocking calls. The decrease in throughput is not acceptable for high data rate links, as the link requires constant data a flow in order for spacecraft and ground radios to stay synchronized, unless significant data is queued a the ground station. In cases where queuing the data is not an option, such as during real time transmissions, the SLE implementation cannot support high data rate communication.

A study of topologies and protocols for fiber optic local area network

NASA Technical Reports Server (NTRS)

Yeh, C.; Gerla, M.; Rodrigues, P.

1985-01-01

The emergence of new applications requiring high data traffic necessitates the development of high speed local area networks. Optical fiber is selected as the transmission medium due to its inherent advantages over other possible media and the dual optical bus architecture is shown to be the most suitable topology. Asynchronous access protocols, including token, random, hybrid random/token, and virtual token schemes, are developed and analyzed. Exact expressions for insertion delay and utilization at light and heavy load are derived, and intermediate load behavior is investigated by simulation. A new tokenless adaptive scheme whose control depends only on the detection of activity on the channel is shown to outperform round-robin schemes under uneven loads and multipacket traffic and to perform optimally at light load. An approximate solution to the queueing delay for an oscillating polling scheme under chaining is obtained and results are compared with simulation. Solutions to the problem of building systems with a large number of stations are presented, including maximization of the number of optical couplers, and the use of passive star/bus topologies, bridges and gateways.

Human oocyte cryopreservation and the fate of cortical granules.

PubMed

Ghetler, Yehudith; Skutelsky, Ehud; Ben Nun, Isaac; Ben Dor, Liah; Amihai, Dina; Shalgi, Ruth

2006-07-01

To examine the effect of the commonly used oocyte cryopreservation protocol on the cortical granules (CGs) of human immature germinal vesicle (GV) and mature metaphase II (MII) oocytes. Laboratory study. IVF unit. Unfertilized, intracytoplasmic sperm injected (ICSI) oocytes, and immature oocytes were cryopreserved using a slow freezing-rapid thawing program with 1,2-propanediol (PROH) as a cryoprotectant. Cortical granule exocytosis (CGE) was assessed by either confocal microscopy or transmission electron microscopy (TEM). The survival rates of frozen-thawed oocytes (mature and immature) were significantly lower compared with zygotes. Both mature and immature oocytes exhibited increased fluorescence after cryopreservation, indicating the occurrence of CGE. Mere exposure of oocytes to cryoprotectants induced CGE of 70% the value of control zygotes. The TEM revealed a drastic reduction in the amount of CGs at the cortex of frozen-thawed GV and MII oocytes, as well as appearance of vesicles in the ooplasm. The commonly used PROH freezing protocol for human oocytes resulted in extensive CGE. This finding explains why ICSI is needed to achieve fertilization of frozen-thawed human oocytes.

A zero-knowledge protocol for nuclear warhead verification

NASA Astrophysics Data System (ADS)

Glaser, Alexander; Barak, Boaz; Goldston, Robert J.

2014-06-01

The verification of nuclear warheads for arms control involves a paradox: international inspectors will have to gain high confidence in the authenticity of submitted items while learning nothing about them. Proposed inspection systems featuring `information barriers', designed to hide measurements stored in electronic systems, are at risk of tampering and snooping. Here we show the viability of a fundamentally new approach to nuclear warhead verification that incorporates a zero-knowledge protocol, which is designed in such a way that sensitive information is never measured and so does not need to be hidden. We interrogate submitted items with energetic neutrons, making, in effect, differential measurements of both neutron transmission and emission. Calculations for scenarios in which material is diverted from a test object show that a high degree of discrimination can be achieved while revealing zero information. Our ideas for a physical zero-knowledge system could have applications beyond the context of nuclear disarmament. The proposed technique suggests a way to perform comparisons or computations on personal or confidential data without measuring the data in the first place.

Challenges and Ideas to Achieve Wireless 100 Gb/s Transmission: An Overview of Challenges and Solutions within the German Research Foundation (DFG) Special Priority Program SPP1655

NASA Astrophysics Data System (ADS)

Kraemer, Rolf

2017-09-01

Wireless communications is one of the fastest growing technology fields, driving numerous other innovations in electronics. One challenging research area within the wireless field is to achieve much higher transmission rates. First products with up to 3 Gb/s are in the market. In the coming years we predict this speed growing quickly up to and beyond 100 Gb/s. Today it is an open question how we can realize a wireless system at this speed. If we intend to use such systems in a mobile environment, we can only afford to spend approximately 1-10 pW/b for the end-to-end communication. This includes RF-transmission and all processing and protocol steps. The SPP1655 of the DFG was set up to investigate new paradigms for achieving the 100 Gb/s wireless transmission goal. Within 11 coordinated projects researchers from all over Germany are addressing several relevant issues ranging from the antennas and RF-Frontend, baseband-processing and error correction to protocol processing. A number of limitations of current approaches have to be investigated and new algorithms must be found in order to achieve the intended goal. One of the big challenges is finding the correct balance between analog and digital signal processing to achieve an extremely high performance at very low energy consumption. Another challenge is to find a good balance between bandwidth and bandwidth efficiency to achieve the 100 Gbps goal. Finally, protocol processing will need new approaches to decouple the central processor of a computer from the high-end input/output operations. Within this editorial we will address the main challenges and briefly outline the approaches of the running projects. The rest of this special issue will be devoted to more detailed descriptions and achievements of the individual projects of SPP1655.

The influence of ferucarbotran on the chondrogenesis of human mesenchymal stem cells

PubMed Central

Henning, Tobias D; Sutton, Elizabeth J; Kim, Anne; Golovko, Daniel; Horvai, Andrew; Ackerman, Larry; Sennino, Barbara; McDonald, Donald; Lotz, Jeffrey; Daldrup-Link, Heike E

2010-01-01

For in vivo applications of magnetically labeled stem cells, biological effects of the labeling procedure have to be precluded. This study evaluates the effect of different Ferucarbotran cell labeling protocols on chondrogenic differentiation of human mesenchymal stem cells (hMSC) as well as their implications for MR imaging. hMSC were labeled with Ferucarbotran using various protocols: Cells were labeled with 100μg Fe/ml for 4h and 18h and additional samples were cultured for 6 or 12 days after the 18-hour labeling. Supplementary samples were labeled by transfection with protamine sulfate. Iron uptake was quantified by ICP-spectrometry and labeled cells were investigated by transmission electron microscopy and by immunostaining for ferucarbotran. The differentiation potential of labeled cells was compared to unlabeled controls by staining with alcian blue and hematoxylin & eosin, then quantified by measurements of glucosaminoglycans (GAG). Contrast agent effect at 3T was investigated on day 1 and day 14 of chondrogenic differentiation by measuring signal-to-noise ratios on T2-SE and T2*-GE-sequences. Iron uptake was significant for all labeling protocols (p< 0.05). The uptake was highest after transfection with protamine sulfate (25.65 ± 3.96 pg/cell) and lowest at an incubation time of 4h without transfection (3.21 ± 0.21 pg/cell). While chondrogenic differentiation was decreased using all labeling protocols, the decrease in GAG synthesis was not significant after labeling for 4h without transfection. After labeling by simple incubation, chondrogenesis was found to be dose-dependent. MR imaging showed markedly lower SNR values of all labeled cells compared to the unlabeled controls. This contrast agent effect persisted for 14 days and the duration of differentiation. Magnetic labeling of hMSC with ferucarbotran inhibits chondrogenesis in a dose-dependent manner when using simple incubation techniques. When decreasing the incubation time to 4h, inhibition of chondrogenesis was not significant. PMID:19670250

Operating CFDP in the Interplanetary Internet

NASA Technical Reports Server (NTRS)

Burleigh, S.

2002-01-01

This paper examines the design elements of CCSDS File Delivery Protocol and Interplanetary Internet technologies that will simplify their integration and discusses the resulting new capabilities, such as efficient transmission of large files via multiple relay satellites operating in parallel.

A comparison of two methods for quantifying parasitic nematode fecundity

USDA-ARS?s Scientific Manuscript database

Accurate measures of nematode fecundity can provide important information for investigating parasite life history evolution, transmission potential, and effects on host health. Understanding differences among fecundity assessment protocols and standardizing methods, where possible, will enable compa...

The Remote Maxwell Demon as Energy Down-Converter

NASA Astrophysics Data System (ADS)

Hossenfelder, S.

2016-04-01

It is demonstrated that Maxwell's demon can be used to allow a machine to extract energy from a heat bath by use of information that is processed by the demon at a remote location. The model proposed here effectively replaces transmission of energy by transmission of information. For that we use a feedback protocol that enables a net gain by stimulating emission in selected fluctuations around thermal equilibrium. We estimate the down conversion rate and the efficiency of energy extraction from the heat bath.

Two-qubit gates and coupling with low-impedance flux qubits

NASA Astrophysics Data System (ADS)

Chow, Jerry; Corcoles, Antonio; Rigetti, Chad; Rozen, Jim; Keefe, George; Rothwell, Mary-Beth; Rohrs, John; Borstelmann, Mark; Divincenzo, David; Ketchen, Mark; Steffen, Matthias

2011-03-01

We experimentally demonstrate the coupling of two low-impedance flux qubits mediated via a transmission line resonator. We explore the viability of experimental coupling protocols which involve selective microwave driving on the qubits independently as well as fast frequency tuning through on-chip flux-bias. Pulse-shaping techniques for single-qubit and two-qubit gates are employed for reducing unwanted leakage and phase errors. A joint readout through the transmission line resonator is used for characterizing single-qubit and two-qubit states.

Assessment of the effect of larval source management and house improvement on malaria transmission when added to standard malaria control strategies in southern Malawi: study protocol for a cluster-randomised controlled trial.

PubMed

McCann, Robert S; van den Berg, Henk; Diggle, Peter J; van Vugt, Michèle; Terlouw, Dianne J; Phiri, Kamija S; Di Pasquale, Aurelio; Maire, Nicolas; Gowelo, Steven; Mburu, Monicah M; Kabaghe, Alinune N; Mzilahowa, Themba; Chipeta, Michael G; Takken, Willem

2017-09-22

Due to outdoor and residual transmission and insecticide resistance, long-lasting insecticidal nets (LLINs) and indoor residual spraying (IRS) will be insufficient as stand-alone malaria vector control interventions in many settings as programmes shift toward malaria elimination. Combining additional vector control interventions as part of an integrated strategy would potentially overcome these challenges. Larval source management (LSM) and structural house improvements (HI) are appealing as additional components of an integrated vector management plan because of their long histories of use, evidence on effectiveness in appropriate settings, and unique modes of action compared to LLINs and IRS. Implementation of LSM and HI through a community-based approach could provide a path for rolling-out these interventions sustainably and on a large scale. We will implement community-based LSM and HI, as additional interventions to the current national malaria control strategies, using a randomised block, 2 × 2 factorial, cluster-randomised design in rural, southern Malawi. These interventions will be continued for two years. The trial catchment area covers about 25,000 people living in 65 villages. Community participation is encouraged by training community volunteers as health animators, and supporting the organisation of village-level committees in collaboration with The Hunger Project, a non-governmental organisation. Household-level cross-sectional surveys, including parasitological and entomological sampling, will be conducted on a rolling, 2-monthly schedule to measure outcomes over two years (2016 to 2018). Coverage of LSM and HI will also be assessed throughout the trial area. Combining LSM and/or HI together with the interventions currently implemented by the Malawi National Malaria Control Programme is anticipated to reduce malaria transmission below the level reached by current interventions alone. Implementation of LSM and HI through a community-based approach provides an opportunity for optimum adaptation to the local ecological and social setting, and enhances the potential for sustainability. Registered with The Pan African Clinical Trials Registry on 3 March 2016, trial number PACTR201604001501493.

Nosocomial outbreak of hepatitis B virus infection in a pediatric hematology and oncology unit in South Africa: Epidemiological investigation and measures to prevent further transmission.

PubMed

Büchner, Ané; Du Plessis, Nicolette M; Reynders, David T; Omar, Fareed E; Mayaphi, Simnikiwe H; Haeri Mazanderani, Ahmad F; Avenant, Theunis

2015-11-01

Hospital-acquired hepatitis B virus (HBV) infection has been well described and continues to occur worldwide. Recent nosocomial outbreaks have been linked to unsafe injection practices, use of multi-dose vials, and poor staff compliance with standard precautions. This report describes a nosocomial outbreak that occurred in a pediatric hematology and oncology unit of a large academic hospital, the epidemiological investigation of the outbreak, and preventive measures implemented to limit further in-hospital transmission. Outbreak investigation including contact tracing and HBV screening were initially carried out on all patients seen by the unit during the same period as the first three cases. Routine screening for the entire patient population of the unit was initiated in February 2013 when it was realized that numerous patients may have been exposed. Forty-nine cases of HBV infection were confirmed in 408 patients tested between July 2011 and October 2013. Phylogenetic analysis of the HBV preC/C gene nucleotide sequences revealed that all tested outbreak strains clustered together. Most (67%) patients were HBeAg positive. The cause of transmission could not be established. Preventive measures targeted three proposed routes. HBV screening and vaccination protocols were started in the unit. The high number of HBeAg positive patients, together with suspected lapses in infection prevention and control measures, are believed to have played a major role in the transmission. Measures implemented to prevent further in-hospital transmission were successful. On-going HBV screening and vaccination programs in pediatric hematology and oncology units should become standard of care. © 2015 Wiley Periodicals, Inc.

Real-Time Surveillance in Emergencies Using the Early Warning Alert and Response Network.

PubMed

Cordes, Kristina M; Cookson, Susan T; Boyd, Andrew T; Hardy, Colleen; Malik, Mamunur Rahman; Mala, Peter; El Tahir, Khalid; Everard, Marthe; Jasiem, Mohamad; Husain, Farah

2017-11-01

Humanitarian emergencies often result in population displacement and increase the risk for transmission of communicable diseases. To address the increased risk for outbreaks during humanitarian emergencies, the World Health Organization developed the Early Warning Alert and Response Network (EWARN) for early detection of epidemic-prone diseases. The US Centers for Disease Control and Prevention has worked with the World Health Organization, ministries of health, and other partners to support EWARN through the implementation and evaluation of these systems and the development of standardized guidance. Although protocols have been developed for the implementation and evaluation of EWARN, a need persists for standardized training and additional guidance on supporting these systems remotely when access to affected areas is restricted. Continued collaboration between partners and the Centers for Disease Control and Prevention for surveillance during emergencies is necessary to strengthen capacity and support global health security.

Real-Time Surveillance in Emergencies Using the Early Warning Alert and Response Network

PubMed Central

Cordes, Kristina M.; Cookson, Susan T.; Boyd, Andrew T.; Hardy, Colleen; Malik, Mamunur Rahman; Mala, Peter; El Tahir, Khalid; Everard, Marthe; Jasiem, Mohamad

2017-01-01

Humanitarian emergencies often result in population displacement and increase the risk for transmission of communicable diseases. To address the increased risk for outbreaks during humanitarian emergencies, the World Health Organization developed the Early Warning Alert and Response Network (EWARN) for early detection of epidemic-prone diseases. The US Centers for Disease Control and Prevention has worked with the World Health Organization, ministries of health, and other partners to support EWARN through the implementation and evaluation of these systems and the development of standardized guidance. Although protocols have been developed for the implementation and evaluation of EWARN, a need persists for standardized training and additional guidance on supporting these systems remotely when access to affected areas is restricted. Continued collaboration between partners and the Centers for Disease Control and Prevention for surveillance during emergencies is necessary to strengthen capacity and support global health security. PMID:29155660

Data transmission and acquisition in NEMO

NASA Astrophysics Data System (ADS)

Bunkheila, G.

2006-11-01

A comprehensive system for data transmission and acquisition has been developed for an "à la NEMO" underwater neutrino telescope based on Čerenkov light detection using photomultipliers (PMTs) as sensors. Signals generated by each sensor are triggered, sampled and tagged by an electronics board, called Front End Module (FEM). Data streams from up to eight FEMs located on one tower floor are collected by a concentration board called Floor Control Module (FCM) and sent to a twin FCM board—located at the onshore station and plugged into an interface machine (FCM Interface, or FCMI) via a PCI bus—through a DWDM-compliant optical fiber and using a self-synchronous serial protocol. All sensor data reach the onshore lab through FCMI where they are made available to subsequent elaboration processes, such as time-wise alignment and muon track event-triggering. To meet requirements of the latter, onshore data unpacking is carried out with respect to their topological origin. The system promised, and keeps on showing, very light charges on power consumption and infrastructure complexity, while having recently proved to behave at high performance levels in its optical part.

[Wireless Passive Body Sensor for Temperature Monitoring Using Near Field Communication Technology].

PubMed

Shi, Bo; Zhang, Li; Zhang, Genxuan; Tsau, Young; Zhang, Sai; Li, Lei

2017-01-01

In this study, we designed a wireless body temperature sensor (WBTS) based on near field communication (NFC) technology. Just attaching the WBTS to a mobile phone with NFC function, the real-time body temperature of human subjects can be acquired by an application program without seperate power supply. The WBTS is mainly composed of a digital body temperature probe (d-BTP), a NFC unit and an antenna. The d-BTP acquires and processes body temperature data through a micro control er, and the NFC unit and antenna are used for wireless energy transmission and data communication between the mobile phone and WBTS. UART communication protocol is used in the communication between the d-BTP and NFC unit, and data compression technique is adopted for improving transmission efficiency and decreasing power loss. In tests, the error of WBTS is ±0.1 oC, in range of 32 oC to 42 oC. The WBTS has advantages of high accuracy, low power loss, strong anti-interference ability, dispensation with independent power supply etc., and it can be integrated into wearable apparatuses for temperature monitoring and health management.

No role for human papillomavirus infection in oral cancers in a region in southern India.

PubMed

Laprise, Claudie; Madathil, Sreenath A; Allison, Paul; Abraham, Priya; Raghavendran, Anantharam; Shahul, Hameed P; ThekkePurakkal, Akhil-Soman; Castonguay, Geneviève; Coutlée, François; Schlecht, Nicolas F; Rousseau, Marie-Claude; Franco, Eduardo L; Nicolau, Belinda

2016-02-15

Oral cancer is a major public health issue in India with ∼ 77,000 new cases and 52,000 deaths yearly. Paan chewing, tobacco and alcohol use are strong risk factors for this cancer in India. Human papillomaviruses (HPVs) are also related to a subset of head and neck cancers (HNCs). We examined the association between oral HPV and oral cancer in a sample of Indian subjects participating in a hospital-based case-control study. We recruited incident oral cancer cases (N = 350) and controls frequency-matched by age and sex (N = 371) from two main referral hospitals in Kerala, South India. Sociodemographic and behavioral data were collected by interviews. Epithelial cells were sampled using Oral CDx® brushes from the oral cancer site and the normal mucosa. Detection and genotyping of 36 HPV genotypes were done using a polymerase chain reaction protocol. Data collection procedures were performed by qualified dentists via a detailed protocol with strict quality control, including independent HPV testing in India and Canada. HPV DNA was detected in none of the cases or controls. Associations between oral cancer and risk factors usually associated with HPV infection, such as oral sex and number of lifetime sexual partners, were examined by logistic regression and were not associated with oral cancer. Lack of a role for HPV infection in this study may reflect cultural or religious characteristics specific to this region in India that are not conducive to oral HPV transmission. A nationwide representative prevalence study is needed to investigate HPV prevalence variability among Indian regions. © 2015 UICC.

Advances Made in the Next Generation of Satellite Networks

NASA Technical Reports Server (NTRS)

Bhasin, Kul B.

1999-01-01

Because of the unique networking characteristics of communications satellites, global satellite networks are moving to the forefront in enhancing national and global information infrastructures. Simultaneously, broadband data services, which are emerging as the major market driver for future satellite and terrestrial networks, are being widely acknowledged as the foundation for an efficient global information infrastructure. In the past 2 years, various task forces and working groups around the globe have identified pivotal topics and key issues to address if we are to realize such networks in a timely fashion. In response, industry, government, and academia undertook efforts to address these topics and issues. A workshop was organized to provide a forum to assess the current state-of-the-art, identify key issues, and highlight the emerging trends in the next-generation architectures, data protocol development, communication interoperability, and applications. The Satellite Networks: Architectures, Applications, and Technologies Workshop was hosted by the Space Communication Program at the NASA Lewis Research Center in Cleveland, Ohio. Nearly 300 executives and technical experts from academia, industry, and government, representing the United States and eight other countries, attended the event (June 2 to 4, 1998). The program included seven panels and invited sessions and nine breakout sessions in which 42 speakers presented on technical topics. The proceedings covers a wide range of topics: access technology and protocols, architectures and network simulations, asynchronous transfer mode (ATM) over satellite networks, Internet over satellite networks, interoperability experiments and applications, multicasting, NASA interoperability experiment programs, NASA mission applications, and Transmission Control Protocol/Internet Protocol (TCP/IP) over satellite: issues, relevance, and experience.

Repeated Transmissions In Mobile/Satellite Communications

NASA Technical Reports Server (NTRS)

Yan, Tsun-Yee; Clare, Loren P.

1988-01-01

Repetition increases throughput and decreases delay. Paper discusses theoretical performance of communication system for land-mobile stations with satellite relay using ALOHA random-access protocol modified for repeated transimssions. Methods and conclusions contribute to general understanding of packet communications in fading channels.

Networks: A Review of Their Technology, Architecture, and Implementation.

ERIC Educational Resources Information Center

Learn, Larry L.

1988-01-01

This overview of network-related technologies covers network elements, analog and digital signals, transmission media and their characteristics, equipment certification, multiplexing, network types, access technologies, network architectures local-area network technologies and attributes, protocols, internetworking, fiber optics versus satellites,…

Quantitative PCR and Digital PCR for Detection of Ascaris lumbricoides Eggs in Reclaimed Water

PubMed Central

Santísima-Trinidad, Ana Belén; Bornay-Llinares, Fernando Jorge; Martín González, Marcos; Pascual Valero, José Antonio; Ros Muñoz, Margarita

2017-01-01

The reuse of reclaimed water from wastewater depuration is a widespread and necessary practice in many areas around the world and must be accompanied by adequate and continuous quality control. Ascaris lumbricoides is one of the soil-transmitted helminths (STH) with risk for humans due to its high infectivity and an important determinant of transmission is the inadequacy of water supplies and sanitation. The World Health Organization (WHO) recommends a limit equal to or lower than one parasitic helminth egg per liter, to reuse reclaimed water for unrestricted irrigation. We present two new protocols of DNA extraction from large volumes of reclaimed water. Quantitative PCR (qPCR) and digital PCR (dPCR) were able to detect low amounts of A. lumbricoides eggs. By using the first extraction protocol, which processes 500 mL of reclaimed water, qPCR can detect DNA concentrations as low as one A. lumbricoides egg equivalent, while dPCR can detect DNA concentrations as low as five A. lumbricoides egg equivalents. By using the second protocol, which processes 10 L of reclaimed water, qPCR was able to detect DNA concentrations equivalent to 20 A. lumbricoides eggs. This fact indicated the importance of developing new methodologies to detect helminth eggs with higher sensitivity and precision avoiding possible human infection risks. PMID:28377928

Internet Protocol Enhanced over Satellite Networks

NASA Technical Reports Server (NTRS)

Ivancic, William D.

1999-01-01

Extensive research conducted by the Satellite Networks and Architectures Branch of the NASA Lewis Research Center led to an experimental change to the Internet's Transmission Control Protocol (TCP) that will increase performance over satellite channels. The change raises the size of the initial burst of data TCP can send from 1 packet to 4 packets or roughly 4 kilobytes (kB), whichever is less. TCP is used daily by everyone on the Internet for e-mail and World Wide Web access, as well as other services. TCP is one of the feature protocols used in computer communications for reliable data delivery and file transfer. Increasing TCP's initial data burst from the previously specified single segment to approximately 4 kB may improve data transfer rates by up to 27 percent for very small files. This is significant because most file transfers in wide-area networks today are small files, 4 kilobytes or less. In addition, because data transfers over geostationary satellites can take 5 to 20 times longer than over typical terrestrial connections, increasing the initial burst of data that can be sent is extremely important. This research along with research from other institutions has led to the release of two new Request for Comments from the Internet Engineering Task Force (IETF, the international body that sets Internet standards). In addition, two studies of the implications of this mechanism were also funded by NASA Lewis.