Innovative research of AD HOC network mobility model

NASA Astrophysics Data System (ADS)

Chen, Xin

2017-08-01

It is difficult for researchers of AD HOC network to conduct actual deployment during experimental stage as the network topology is changeable and location of nodes is unfixed. Thus simulation still remains the main research method of the network. Mobility model is an important component of AD HOC network simulation. It is used to describe the movement pattern of nodes in AD HOC network (including location and velocity, etc.) and decides the movement trail of nodes, playing as the abstraction of the movement modes of nodes. Therefore, mobility model which simulates node movement is an important foundation for simulation research. In AD HOC network research, mobility model shall reflect the movement law of nodes as truly as possible. In this paper, node generally refers to the wireless equipment people carry. The main research contents include how nodes avoid obstacles during movement process and the impacts of obstacles on the mutual relation among nodes, based on which a Node Self Avoiding Obstacle, i.e. NASO model is established in AD HOC network.

14 CFR 1203.903 - Ad hoc committees.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 5 2011-01-01 2010-01-01 true Ad hoc committees. 1203.903 Section 1203.903 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION INFORMATION SECURITY PROGRAM NASA Information Security Program Committee § 1203.903 Ad hoc committees. The Chairperson is authorized to...

Where Do Community Colleges Stand?

ERIC Educational Resources Information Center

Pietak, Raymond

1971-01-01

Traditional clubs and structures continue to serve needs of interested students. However, more socially aware students must have operational vehicles to meet their dynamic needs. The identification of problem areas and the creation of ad hoc interest groups should be added to the college activity programs. (Author)

Assured Information Sharing for Ad-Hoc Collaboration

ERIC Educational Resources Information Center

Jin, Jing

2009-01-01

Collaborative information sharing tends to be highly dynamic and often ad hoc among organizations. The dynamic natures and sharing patterns in ad-hoc collaboration impose a need for a comprehensive and flexible approach to reflecting and coping with the unique access control requirements associated with the environment. This dissertation…

75 FR 43565 - NASA Advisory Council; Ad-Hoc Task Force on Planetary Defense; Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-26

... NATIONAL AERONAUTICS AND SPACE ADMINISTRATION [Notice: (10-084)] NASA Advisory Council; Ad-Hoc Task Force on Planetary Defense; Meeting AGENCY: National Aeronautics and Space Administration. ACTION... amended, the National Aeronautics and Space Administration announces a two-part meeting of the Ad-Hoc Task...

75 FR 33838 - NASA Advisory Council; Ad-Hoc Task Force on Planetary Defense; Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-15

... NATIONAL AERONAUTICS AND SPACE ADMINISTRATION [Notice (10-065)] NASA Advisory Council; Ad-Hoc Task Force on Planetary Defense; Meeting AGENCY: National Aeronautics and Space Administration. ACTION... amended, the National Aeronautics and Space Administration announces a meeting of the Ad-Hoc Task Force on...

75 FR 15742 - NASA Advisory Council; Ad-Hoc Task Force on Planetary Defense; Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-30

... NATIONAL AERONAUTICS AND SPACE ADMINISTRATION [Notice: (10-035)] NASA Advisory Council; Ad-Hoc Task Force on Planetary Defense; Meeting AGENCY: National Aeronautics and Space Administration. ACTION... amended, the National Aeronautics and Space Administration announces a meeting of the Ad-Hoc Task Force on...

Research of Ad Hoc Networks Access Algorithm

NASA Astrophysics Data System (ADS)

Xiang, Ma

With the continuous development of mobile communication technology, Ad Hoc access network has become a hot research, Ad Hoc access network nodes can be used to expand capacity of multi-hop communication range of mobile communication system, even business adjacent to the community, improve edge data rates. When the ad hoc network is the access network of the internet, the gateway discovery protocol is very important to choose the most appropriate gateway to guarantee the connectivity between ad hoc network and IP based fixed networks. The paper proposes a QoS gateway discovery protocol which uses the time delay and stable route to the gateway selection conditions. And according to the gateway discovery protocol, it also proposes a fast handover scheme which can decrease the handover time and improve the handover efficiency.

Supporting Dynamic Ad hoc Collaboration Capabilities

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

Agarwal, Deborah A.; Berket, Karlo

2003-07-14

Modern HENP experiments such as CMS and Atlas involve as many as 2000 collaborators around the world. Collaborations this large will be unable to meet often enough to support working closely together. Many of the tools currently available for collaboration focus on heavy-weight applications such as videoconferencing tools. While these are important, there is a more basic need for tools that support connecting physicists to work together on an ad hoc or continuous basis. Tools that support the day-to-day connectivity and underlying needs of a group of collaborators are important for providing light-weight, non-intrusive, and flexible ways to work collaboratively.more » Some example tools include messaging, file-sharing, and shared plot viewers. An important component of the environment is a scalable underlying communication framework. In this paper we will describe our current progress on building a dynamic and ad hoc collaboration environment and our vision for its evolution into a HENP collaboration environment.« less

Maintaining Limited-Range Connectivity Among Second-Order Agents

DTIC Science & Technology

2016-07-07

we consider ad-hoc networks of robotic agents with double integrator dynamics. For such networks, the connectivity maintenance problems are: (i) do...hoc networks of mobile autonomous agents. This loose ter- minology refers to groups of robotic agents with limited mobility and communica- tion...connectivity can be preserved. 3.1. Networks of robotic agents with second-order dynamics and the connectivity maintenance problem. We begin by

Overview of a Crash Energy Management Specification for Passenger Rail Equipment

DOT National Transportation Integrated Search

2007-04-04

At the request of METROLINK, the Federal Railroad : Administration (FRA), with the Federal Transit Administration and the : American Public Transportation Association, formed the ad hoc Crash : Energy Management Working Group in May 2005. This group ...

A Feasible Approach for an Early Manned Lunar Landing. Part II: Detailed Report of Ad Hoc Task Group

NASA Technical Reports Server (NTRS)

Fleming, William A.

1961-01-01

This report, in two parts, presents a program development plan for attempting a first manned lunar landing in 1967. The two parts consist of a Summary Report and a Detailed Report representing the coordinated output of the Ad Hoc Task Group assigned to the study. The study was started in response to the request for such a study by the Associate Administrator in his memorandum of May 2, 1961 establishing the Ad Hoc Task Group. The purpose of the study was to take a first cut at the tasks associated with the design, development and construction of the equipment and facilities as well as the development of the crews, and to show the time phasing 6f these tasks. Included are the space sciences, life science and advanced technology tasks whose data and results are needed for designing and developing the systems required in carrying out the mission. The plan presented in the two reports does not presume to be a firm plan. Its basic purpose is, by choosing one feasible method, to size up the scope, schedule and cost of the job, discover the main problems, pacing items and major decisions and provide a threshold from which a firm and detailed project development plan can be jointly formulated by the various elements of NASA.

Typicality Mediates Performance during Category Verification in Both Ad-Hoc and Well-Defined Categories

ERIC Educational Resources Information Center

Sandberg, Chaleece; Sebastian, Rajani; Kiran, Swathi

2012-01-01

Background: The typicality effect is present in neurologically intact populations for natural, ad-hoc, and well-defined categories. Although sparse, there is evidence of typicality effects in persons with chronic stroke aphasia for natural and ad-hoc categories. However, it is unknown exactly what influences the typicality effect in this…

Research opportunities in cardiovascular deconditioning, phase 1

NASA Technical Reports Server (NTRS)

Levy, M. N. (Editor); Talbot, J. M. (Editor)

1983-01-01

The deconditioning of the cardiovascular system that occurs during spaceflight, NASA's current and projected research program, and the conclusions and suggestions of the ad hoc Working Group are summarized.

Protocols for Detection and Removal of Wormholes for Secure Routing and Neighborhood Creation in Wireless Ad Hoc Networks

ERIC Educational Resources Information Center

Hayajneh, Thaier Saleh

2009-01-01

Wireless ad hoc networks are suitable and sometimes the only solution for several applications. Many applications, particularly those in military and critical civilian domains (such as battlefield surveillance and emergency rescue) require that ad hoc networks be secure and stable. In fact, security is one of the main barriers to the extensive use…

Ad Hoc Supervision of General Practice Registrars as a "Community of Practice": Analysis, Interpretation and Re-Presentation

ERIC Educational Resources Information Center

Clement, T.; Brown, J.; Morrison, J.; Nestel, D.

2016-01-01

General practice registrars in Australia undertake most of their vocational training in accredited general practices. They typically see patients alone from the start of their community-based training and are expected to seek timely ad hoc support from their supervisor. Such ad hoc encounters are a mechanism for ensuring patient safety, but also…

Ad Hoc Categories and False Memories: Memory Illusions for Categories Created On-The-Spot

ERIC Educational Resources Information Center

Soro, Jerônimo C.; Ferreira, Mário B.; Semin, Gün R.; Mata, André; Carneiro, Paula

2017-01-01

Three experiments were designed to test whether experimentally created ad hoc associative networks evoke false memories. We used the DRM (Deese, Roediger, McDermott) paradigm with lists of ad hoc categories composed of exemplars aggregated toward specific goals (e.g., going for a picnic) that do not share any consistent set of features. Experiment…

Ad hoc Laser networks component technology for modular spacecraft

NASA Astrophysics Data System (ADS)

Huang, Xiujun; Shi, Dele; Ma, Zongfeng; Shen, Jingshi

2016-03-01

Distributed reconfigurable satellite is a new kind of spacecraft system, which is based on a flexible platform of modularization and standardization. Based on the module data flow analysis of the spacecraft, this paper proposes a network component of ad hoc Laser networks architecture. Low speed control network with high speed load network of Microwave-Laser communication mode, no mesh network mode, to improve the flexibility of the network. Ad hoc Laser networks component technology was developed, and carried out the related performance testing and experiment. The results showed that ad hoc Laser networks components can meet the demand of future networking between the module of spacecraft.

Ad hoc laser networks component technology for modular spacecraft

NASA Astrophysics Data System (ADS)

Huang, Xiujun; Shi, Dele; Shen, Jingshi

2017-10-01

Distributed reconfigurable satellite is a new kind of spacecraft system, which is based on a flexible platform of modularization and standardization. Based on the module data flow analysis of the spacecraft, this paper proposes a network component of ad hoc Laser networks architecture. Low speed control network with high speed load network of Microwave-Laser communication mode, no mesh network mode, to improve the flexibility of the network. Ad hoc Laser networks component technology was developed, and carried out the related performance testing and experiment. The results showed that ad hoc Laser networks components can meet the demand of future networking between the module of spacecraft.

The effects of malicious nodes on performance of mobile ad hoc networks

NASA Astrophysics Data System (ADS)

Li, Fanzhi; Shi, Xiyu; Jassim, Sabah; Adams, Christopher

2006-05-01

Wireless ad hoc networking offers convenient infrastructureless communication over the shared wireless channel. However, the nature of ad hoc networks makes them vulnerable to security attacks. Unlike their wired counterpart, infrastructureless ad hoc networks do not have a clear line of defense, their topology is dynamically changing, and every mobile node can receive messages from its neighbors and can be contacted by all other nodes in its neighborhood. This poses a great danger to network security if some nodes behave in a malicious manner. The immediate concern about the security in this type of networks is how to protect the network and the individual mobile nodes against malicious act of rogue nodes from within the network. This paper is concerned with security aspects of wireless ad hoc networks. We shall present results of simulation experiments on ad hoc network's performance in the presence of malicious nodes. We shall investigate two types of attacks and the consequences will be simulated and quantified in terms of loss of packets and other factors. The results show that network performance, in terms of successful packet delivery ratios, significantly deteriorates when malicious nodes act according to the defined misbehaving characteristics.

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).

Interference Drop Scheme: Enhancing QoS Provision in Multi-Hop Ad Hoc Networks

NASA Astrophysics Data System (ADS)

Luo, Chang-Yi; Komuro, Nobuyoshi; Takahashi, Kiyoshi; Kasai, Hiroyuki; Ueda, Hiromi; Tsuboi, Toshinori

Ad hoc networking uses wireless technologies to construct networks with no physical infrastructure and so are expected to provide instant networking in areas such as disaster recovery sites and inter-vehicle communication. Unlike conventional wired networks services, services in ad hoc networks are easily disrupted by the frequent changes in traffic and topology. Therefore, solutions to assure the Quality of Services (QoS) in ad hoc networks are different from the conventional ones used in wired networks. In this paper, we propose a new queue management scheme, Interference Drop Scheme (IDS) for ad hoc networks. In the conventional queue management approaches such as FIFO (First-in First-out) and RED (Random Early Detection), a queue is usually managed by a queue length limit. FIFO discards packets according to the queue limit, and RED discards packets in an early and random fashion. IDS, on the other hand, manages the queue according to wireless interference time, which increases as the number of contentions in the MAC layer increases. When there are many MAC contentions, IDS discards TCP data packets. By observing the interference time and discarding TCP data packets, our simulation results show that IDS improves TCP performance and reduces QoS violations in UDP in ad hoc networks with chain, grid, and random topologies. Our simulation results also demonstrate that wireless interference time is a better metric than queue length limit for queue management in multi-hop ad hoc networks.

7 CFR 3400.14 - Proposal review.

Code of Federal Regulations, 2010 CFR

2010-01-01

... SERVICE, DEPARTMENT OF AGRICULTURE SPECIAL RESEARCH GRANTS PROGRAM Scientific Peer Review of Research... employees of the Department, the respective peer review group, and ad hoc reviewers, as required. Written...-depth discussions will be provided by peer review group members prior to recommending applications for...

Mobile Security Enclaves

DTIC Science & Technology

2011-09-01

LAI Location Area Identity MANET Mobile Ad - hoc Network MCC Mobile Country Code MCD Mobile Communications Device MNC Mobile Network Code ...tower or present within a geographical area. These conditions relate directly to users who often operate with mobile ad - hoc networks. These types of...infrastructures. First responders can use these mobile base stations to set up their own networks on the fly, similar to mobile ad - hoc networks

Packets Distributing Evolutionary Algorithm Based on PSO for Ad Hoc Network

NASA Astrophysics Data System (ADS)

Xu, Xiao-Feng

2018-03-01

Wireless communication network has such features as limited bandwidth, changeful channel and dynamic topology, etc. Ad hoc network has lots of difficulties in accessing control, bandwidth distribution, resource assign and congestion control. Therefore, a wireless packets distributing Evolutionary algorithm based on PSO (DPSO)for Ad Hoc Network is proposed. Firstly, parameters impact on performance of network are analyzed and researched to obtain network performance effective function. Secondly, the improved PSO Evolutionary Algorithm is used to solve the optimization problem from local to global in the process of network packets distributing. The simulation results show that the algorithm can ensure fairness and timeliness of network transmission, as well as improve ad hoc network resource integrated utilization efficiency.

Receiver-Based Ad Hoc On Demand Multipath Routing Protocol for Mobile Ad Hoc Networks

PubMed Central

Al-Nahari, Abdulaziz; Mohamad, Mohd Murtadha

2016-01-01

Decreasing the route rediscovery time process in reactive routing protocols is challenging in mobile ad hoc networks. Links between nodes are continuously established and broken because of the characteristics of the network. Finding multiple routes to increase the reliability is also important but requires a fast update, especially in high traffic load and high mobility where paths can be broken as well. The sender node keeps re-establishing path discovery to find new paths, which makes for long time delay. In this paper we propose an improved multipath routing protocol, called Receiver-based ad hoc on demand multipath routing protocol (RB-AOMDV), which takes advantage of the reliability of the state of the art ad hoc on demand multipath distance vector (AOMDV) protocol with less re-established discovery time. The receiver node assumes the role of discovering paths when finding data packets that have not been received after a period of time. Simulation results show the delay and delivery ratio performances are improved compared with AOMDV. PMID:27258013

CSR: Constrained Selfish Routing in Ad-Hoc Networks

NASA Astrophysics Data System (ADS)

Bassem, Christine; Bestavros, Azer

Routing protocols for ad-hoc networks assume that the nodes forming the network are either under a single authority, or else that they would be altruistically forwarding data for other nodes with no expectation of a return. These assumptions are unrealistic since in ad-hoc networks, nodes are likely to be autonomous and rational (selfish), and thus unwilling to help unless they have an incentive to do so. Providing such incentives is an important aspect that should be considered when designing ad-hoc routing protocols. In this paper, we propose a dynamic, decentralized routing protocol for ad-hoc networks that provides incentives in the form of payments to intermediate nodes used to forward data for others. In our Constrained Selfish Routing (CSR) protocol, game-theoretic approaches are used to calculate payments (incentives) that ensure both the truthfulness of participating nodes and the fairness of the CSR protocol. We show through simulations that CSR is an energy efficient protocol and that it provides lower communication overhead in the best and average cases compared to existing approaches.

Receiver-Based Ad Hoc On Demand Multipath Routing Protocol for Mobile Ad Hoc Networks.

PubMed

Al-Nahari, Abdulaziz; Mohamad, Mohd Murtadha

2016-01-01

Decreasing the route rediscovery time process in reactive routing protocols is challenging in mobile ad hoc networks. Links between nodes are continuously established and broken because of the characteristics of the network. Finding multiple routes to increase the reliability is also important but requires a fast update, especially in high traffic load and high mobility where paths can be broken as well. The sender node keeps re-establishing path discovery to find new paths, which makes for long time delay. In this paper we propose an improved multipath routing protocol, called Receiver-based ad hoc on demand multipath routing protocol (RB-AOMDV), which takes advantage of the reliability of the state of the art ad hoc on demand multipath distance vector (AOMDV) protocol with less re-established discovery time. The receiver node assumes the role of discovering paths when finding data packets that have not been received after a period of time. Simulation results show the delay and delivery ratio performances are improved compared with AOMDV.

Analysis of Pervasive Mobile Ad Hoc Routing Protocols

NASA Astrophysics Data System (ADS)

Qadri, Nadia N.; Liotta, Antonio

Mobile ad hoc networks (MANETs) are a fundamental element of pervasive networks and therefore, of pervasive systems that truly support pervasive computing, where user can communicate anywhere, anytime and on-the-fly. In fact, future advances in pervasive computing rely on advancements in mobile communication, which includes both infrastructure-based wireless networks and non-infrastructure-based MANETs. MANETs introduce a new communication paradigm, which does not require a fixed infrastructure - they rely on wireless terminals for routing and transport services. Due to highly dynamic topology, absence of established infrastructure for centralized administration, bandwidth constrained wireless links, and limited resources in MANETs, it is challenging to design an efficient and reliable routing protocol. This chapter reviews the key studies carried out so far on the performance of mobile ad hoc routing protocols. We discuss performance issues and metrics required for the evaluation of ad hoc routing protocols. This leads to a survey of existing work, which captures the performance of ad hoc routing algorithms and their behaviour from different perspectives and highlights avenues for future research.

The impact of brief team communication, leadership and team behavior training on ad hoc team performance in trauma care settings.

PubMed

Roberts, Nicole K; Williams, Reed G; Schwind, Cathy J; Sutyak, John A; McDowell, Christopher; Griffen, David; Wall, Jarrod; Sanfey, Hilary; Chestnut, Audra; Meier, Andreas H; Wohltmann, Christopher; Clark, Ted R; Wetter, Nathan

2014-02-01

Communication breakdowns and care coordination problems often cause preventable adverse patient care events, which can be especially acute in the trauma setting, in which ad hoc teams have little time for advanced planning. Existing teamwork curricula do not address the particular issues associated with ad hoc emergency teams providing trauma care. Ad hoc trauma teams completed a preinstruction simulated trauma encounter and were provided with instruction on appropriate team behaviors and team communication. Teams completed a postinstruction simulated trauma encounter immediately afterward and 3 weeks later, then completed a questionnaire. Blinded raters rated videotapes of the simulations. Participants expressed high levels of satisfaction and intent to change practice after the intervention. Participants changed teamwork and communication behavior on the posttest, and changes were sustained after a 3-week interval, though there was some loss of retention. Brief training exercises can change teamwork and communication behaviors on ad hoc trauma teams. Copyright © 2014 Elsevier Inc. All rights reserved.

Data Mining of Extremely Large Ad Hoc Data Sets to Produce Inverted Indices

DTIC Science & Technology

2016-06-01

NAVAL POSTGRADUATE SCHOOL MONTEREY, CALIFORNIA THESIS Approved for public release; distribution is unlimited DATA MINING OF...COVERED Master’s Thesis 4. TITLE AND SUBTITLE DATA MINING OF EXTREMELY LARGE AD HOC DATA SETS TO PRODUCE INVERTED INDICES 5. FUNDING NUMBERS 6...INTENTIONALLY LEFT BLANK iii Approved for public release; distribution is unlimited DATA MINING OF EXTREMELY LARGE AD HOC DATA SETS TO PRODUCE

Reputation-Based Internet Protocol Security: A Multilayer Security Framework for Mobile Ad Hoc Networks

DTIC Science & Technology

2010-09-01

secure ad-hoc networks of mobile sensors deployed in a hostile environment . These sensors are normally small 86 and resource...Communications Magazine, 51, 2008. 45. Kumar, S.A. “Classification and Review of Security Schemes in Mobile Comput- ing”. Wireless Sensor Network , 2010... Networks ”. Wireless /Mobile Network Security , 2008. 85. Xiao, Y. “Accountability for Wireless LANs, Ad Hoc Networks , and Wireless

Small Group Cooperative Curriculum and Experimental Evaluation; A Study of Cooperation Training. Final Report.

ERIC Educational Resources Information Center

Bloom, Joan R.; And Others

This report describes a project to test the effectiveness of a small-group curriculum designed to teach cooperative group work. The sample of 53 groups of boys and 47 groups of girls was assigned to one of three conditions: (a) established groups, (b) ad hoc groups, and (c) control condition groups. Groups who had training were predicted to choose…

Mission and Professionalism: What Teachers Can Do.

ERIC Educational Resources Information Center

Ause, John

1985-01-01

The growing teacher shortage and increasing bureaucratization of schools make it imperative that new means be developed to make teaching more attractive as a profession. Teacher organizations, professional newsletters, informal discussion groups, networking, ad hoc pressure groups, and alternative schools might provide some route to reform. (KH)

Initial Report of the Deans Cyber Warfare Ad Hoc Committee

DTIC Science & Technology

2011-12-22

in a cyber warfare environment. Among the more notable recent developments have been the establishment of a new Cyber Warfare Command (USCYBERCOM) at...information-warfare-centric organization. Clearly, future Naval Academy graduates will be expected to know more about cyber warfare than those we have...graduated in the past. The Academic Dean and Provost tasked an ad hoc committeethe Cyber Warfare ad hoc Committeeto examine how USNA can best ensure that

A Decentralized VPN Service over Generalized Mobile Ad-Hoc Networks

NASA Astrophysics Data System (ADS)

Fujita, Sho; Shima, Keiichi; Uo, Yojiro; Esaki, Hiroshi

We present a decentralized VPN service that can be built over generalized mobile ad-hoc networks (Generalized MANETs), in which topologies can be represented as a time-varying directed multigraph. We address wireless ad-hoc networks and overlay ad-hoc networks as instances of Generalized MANETs. We first propose an architecture to operate on various kinds of networks through a single set of operations. Then, we design and implement a decentralized VPN service on the proposed architecture. Through the development and operation of a prototype system we implemented, we found that the proposed architecture makes the VPN service applicable to each instance of Generalized MANETs, and that the VPN service makes it possible for unmodified applications to operate on the networks.

Research opportunities in space motion sickness, phase 2

NASA Technical Reports Server (NTRS)

Talbot, J. M.

1983-01-01

Space and motion sickness, the current and projected NASA research program, and the conclusions and suggestions of the ad hoc Working Group are summarized. The frame of reference for the report is ground-based research.

Effective Ad-Hoc Committees.

ERIC Educational Resources Information Center

Young, David G.

1983-01-01

Ad-hoc committees may be symbolic, informational, or action committees. A literature survey indicates such committees' structural components include a suprasystem and three subsystems involving linkages, production, and implementation. Other variables include size, personal factors, and timing. All the factors carry implications about ad-hoc…

42 CFR 422.2262 - Review and distribution of marketing materials.

Code of Federal Regulations, 2010 CFR

2010-10-01

... HUMAN SERVICES (CONTINUED) MEDICARE PROGRAM MEDICARE ADVANTAGE PROGRAM Medicare Advantage Marketing... model materials. (d) Ad hoc enrollee communication materials. Ad hoc enrollee communication materials...

The Partisan Battle over Academic Freedom

ERIC Educational Resources Information Center

Chronicle of Higher Education, 2007

2007-01-01

Citing a pattern of outside interest groups aggressively seeking to impose their influence on recent collegiate hiring and tenure decisions, five prominent professors have formed the Ad Hoc Committee to Defend the University. They are circulating an online petition that takes explicit aim at "groups portraying themselves as defenders of Israel,"…

Defense Acquisition and the Case of the Joint Capabilities Technology Demonstration Office: Ad Hoc Problem Solving as a Mechanism for Adaptive Change

DTIC Science & Technology

2013-04-01

Capabilities Technology Demonstration Office: Ad Hoc Problem Solving as a Mechanism for Adaptive Change Kathryn Aten and John T. Dillard Naval...Defense Acquisition and the Case of the Joint Capabilities Technology Demonstration Office: Ad Hoc Problem Solving as a Mechanism for Adaptive Change...describes the preliminary analysis and findings of our study exploring what drives successful organizational adaptation in the context of technology

Defense Acquisition and the Case of the Joint Capabilities Technology Demonstration Office: Ad Hoc Problem Solving as a Mechanism for Adaptive Change

DTIC Science & Technology

2013-10-01

pmlkploba=obmloq=pbofbp= Defense Acquisition and the Case of the Joint Capabilities Technology Demonstration Office: Ad Hoc Problem Solving as a...of the Joint Capabilities Technology Demonstration Office: Ad Hoc Problem Solving as a Mechanism for Adaptive Change 5a. CONTRACT NUMBER 5b. GRANT...findings of our study exploring what drives successful organizational adaptation in the context of technology transition and acquisition within the

Prototyping and Simulation of Robot Group Intelligence using Kohonen Networks.

PubMed

Wang, Zhijun; Mirdamadi, Reza; Wang, Qing

2016-01-01

Intelligent agents such as robots can form ad hoc networks and replace human being in many dangerous scenarios such as a complicated disaster relief site. This project prototypes and builds a computer simulator to simulate robot kinetics, unsupervised learning using Kohonen networks, as well as group intelligence when an ad hoc network is formed. Each robot is modeled using an object with a simple set of attributes and methods that define its internal states and possible actions it may take under certain circumstances. As the result, simple, reliable, and affordable robots can be deployed to form the network. The simulator simulates a group of robots as an unsupervised learning unit and tests the learning results under scenarios with different complexities. The simulation results show that a group of robots could demonstrate highly collaborative behavior on a complex terrain. This study could potentially provide a software simulation platform for testing individual and group capability of robots before the design process and manufacturing of robots. Therefore, results of the project have the potential to reduce the cost and improve the efficiency of robot design and building.

Prototyping and Simulation of Robot Group Intelligence using Kohonen Networks

PubMed Central

Wang, Zhijun; Mirdamadi, Reza; Wang, Qing

2016-01-01

Intelligent agents such as robots can form ad hoc networks and replace human being in many dangerous scenarios such as a complicated disaster relief site. This project prototypes and builds a computer simulator to simulate robot kinetics, unsupervised learning using Kohonen networks, as well as group intelligence when an ad hoc network is formed. Each robot is modeled using an object with a simple set of attributes and methods that define its internal states and possible actions it may take under certain circumstances. As the result, simple, reliable, and affordable robots can be deployed to form the network. The simulator simulates a group of robots as an unsupervised learning unit and tests the learning results under scenarios with different complexities. The simulation results show that a group of robots could demonstrate highly collaborative behavior on a complex terrain. This study could potentially provide a software simulation platform for testing individual and group capability of robots before the design process and manufacturing of robots. Therefore, results of the project have the potential to reduce the cost and improve the efficiency of robot design and building. PMID:28540284

Validity of a semantically cued recall procedure for the mini-mental state examination.

PubMed

Yuspeh, R L; Vanderploeg, R D; Kershaw, D A

1998-10-01

The validity of supplementing the three-item recall portion of the Mini-Mental State Examination (MMSE) with a cued recall procedure to help specify the nature of patients' memory problems was examined. Subjects were 247 individuals representing three diagnostic groups: Alzheimer's disease (AD), subcortical vascular ischemic dementia (SVaD), and normal controls. Individuals were administered a battery of neuropsychological tests, including the MMSE, as part of a comprehensive evaluation for the presence of dementia or other neurologic disorder. MMSE performance differed among groups. The three-item free recall performance also differed among groups, with post hoc analyses revealing the AD and SVaD groups were more impaired than controls but did not differ significantly from each other. Following a cued recall procedure of the MMSE three-items, groups differed, with post hoc analyses showing that AD patients failed to benefit from cues, whereas SVaD patients performed significantly better and comparable to control subjects. Significant correlations between the MMSE three-item cued recall performance and other memory measures demonstrated concurrent validity. Consistent with previous research indicating that SVaD is associated with memory encoding and retrieval deficits, whereas AD is associated with consolidation and storage problems, the present study supported the validity of the cued recall procedure of the three items on the MMSE in helping to distinguish between patients with AD and those with a vascular dementia with primarily subcortical pathology; however, despite these findings, a more extensive battery of neuropsychological measures is still recommended to consistently assess subtle diagnostic differences in these memory processes.

42 CFR 423.2262 - Review and distribution of marketing materials.

Code of Federal Regulations, 2010 CFR

2010-10-01

... HUMAN SERVICES (CONTINUED) MEDICARE PROGRAM VOLUNTARY MEDICARE PRESCRIPTION DRUG BENEFIT Part D...) Ad hoc enrollee communication materials. Ad hoc enrollee communication materials may be reviewed by...

A fault-tolerant small world topology control model in ad hoc networks for search and rescue

NASA Astrophysics Data System (ADS)

Tan, Mian; Fang, Ling; Wu, Yue; Zhang, Bo; Chang, Bowen; Holme, Petter; Zhao, Jing

2018-02-01

Due to their self-organized, multi-hop and distributed characteristics, ad hoc networks are useful in search and rescue. Topology control models need to be designed for energy-efficient, robust and fast communication in ad hoc networks. This paper proposes a topology control model which specializes for search and rescue-Compensation Small World-Repeated Game (CSWRG)-which integrates mobility models, constructing small world networks and a game-theoretic approach to the allocation of resources. Simulation results show that our mobility models can enhance the communication performance of the constructed small-world networks. Our strategy, based on repeated game, can suppress selfish behavior and compensate agents that encounter selfish or faulty neighbors. This model could be useful for the design of ad hoc communication networks.

Intelligent Sensing and Classification in DSR-Based Ad Hoc Networks

NASA Astrophysics Data System (ADS)

Dempsey, Tae; Sahin, Gokhan; Morton, Yu T. (Jade

Wireless ad hoc networks have fundamentally altered today's battlefield, with applications ranging from unmanned air vehicles to randomly deployed sensor networks. Security and vulnerabilities in wireless ad hoc networks have been considered at different layers, and many attack strategies have been proposed, including denial of service (DoS) through the intelligent jamming of the most critical packet types of flows in a network. This paper investigates the effectiveness of intelligent jamming in wireless ad hoc networks using the Dynamic Source Routing (DSR) and TCP protocols and introduces an intelligent classifier to facilitate the jamming of such networks. Assuming encrypted packet headers and contents, our classifier is based solely on the observable characteristics of size, inter-arrival timing, and direction and classifies packets with up to 99.4% accuracy in our experiments.

Design & Engineering Standards « Coast Guard Maritime Commons

Science.gov Websites

Washington, D.C., June 5, 2018, in preparation for the upcoming intersessional working group meeting of the that intersessional working group meeting. 5/21/2018: U.S. Maritime Advisory 2018-008 - Global Measles measures for onboard lifting appliances and winches, and an ad hoc drafting group on the develop of

Experimentally Assessing a Resource-Effective Design for ODL Environments

ERIC Educational Resources Information Center

Karoulis, Athanasis; Sfetsos, Panagiotis; Stamelos, Ioannis; Angelis, Lefteris; Pombortsis, Andreas

2004-01-01

This study is concerned with the formal assessment of a Distance Learning Environment (DLE) created to deliver a course on UML sequence diagrams to university-level students, divided into control and treatment groups. An ad-hoc DLE was constructed to deliver instruction to the treatment group, while the control group was taught in a traditional…

Canadian Mathematics Education Study Group = Groupe Canadian d'Etude en Didactique des Mathmatiques. Proceedings of the Annual Meeting (Burnaby, British Columbia, Canada, May 25-29, 1990).

ERIC Educational Resources Information Center

Quigley, Martyn, Ed.

These conference proceedings include two invited lectures, three working group reports, three topic group reports, two Ad Hoc group reports, a round table report, a list of participants, and a list of previous proceedings. The invited lectures were: "Values in Mathematics Education" (Ubiratan D'Ambrosio) and "Remarks on…

75 FR 20984 - Mid-Atlantic Fishery Management Council (MAFMC); Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-22

... Mid-Atlantic Fishery Management Council's (MAFMC) Ad Hoc Search Committee will hold a closed meeting... Executive Director. The Ad Hoc Search Committee will interview candidates for this position so as to...

29 CFR 1912.11 - Terms of ad hoc committee members.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 29 Labor 7 2011-07-01 2011-07-01 false Terms of ad hoc committee members. 1912.11 Section 1912.11 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) ADVISORY COMMITTEES ON STANDARDS Organizational Matters § 1912.11 Terms of ad...

29 CFR 1912.11 - Terms of ad hoc committee members.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 29 Labor 7 2010-07-01 2010-07-01 false Terms of ad hoc committee members. 1912.11 Section 1912.11 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) ADVISORY COMMITTEES ON STANDARDS Organizational Matters § 1912.11 Terms of ad...

Cutting Corners: Provider Perceptions of Interpretation Services and Factors Related to Use of an Ad Hoc Interpreter.

PubMed

Mayo, Rachel; Parker, Veronica G; Sherrill, Windsor W; Coltman, Kinneil; Hudson, Matthew F; Nichols, Christina M; Yates, Adam M; Pribonic, Anne Paige

2016-06-01

This study assessed health providers' perceptions of factors related to professional interpretation services and the association between these factors and the potential use of ad hoc interpreters. Data were collected from a convenience sample of 150 health services providers at a large, regional health system in South Carolina. Providers rated "ability to communicate effectively during a clinical encounter" as paramount regarding the use of interpretation services. The most important factors related to the likely use of ad hoc interpreters (cutting corners) included locating a qualified interpreter, having to wait for a qualified interpreter, and technical difficulties regarding phone and video technology. Health care organizations may benefit from increasing staff awareness about patient safety and legal and regulatory risks involved with the use of ad hoc interpreters. © The Author(s) 2016.

Impact of network structure on the capacity of wireless multihop ad hoc communication

NASA Astrophysics Data System (ADS)

Krause, Wolfram; Glauche, Ingmar; Sollacher, Rudolf; Greiner, Martin

2004-07-01

As a representative of a complex technological system, the so-called wireless multihop ad hoc communication networks are discussed. They represent an infrastructure-less generalization of todays wireless cellular phone networks. Lacking a central control authority, the ad hoc nodes have to coordinate themselves such that the overall network performs in an optimal way. A performance indicator is the end-to-end throughput capacity. Various models, generating differing ad hoc network structure via differing transmission power assignments, are constructed and characterized. They serve as input for a generic data traffic simulation as well as some semi-analytic estimations. The latter reveal that due to the most-critical-node effect the end-to-end throughput capacity sensitively depends on the underlying network structure, resulting in differing scaling laws with respect to network size.

Assessing Clinical Microbiology Practice Guidelines: American Society for Microbiology Ad Hoc Committee on Evidence-Based Laboratory Medicine Practice Guidelines Assessment

PubMed Central

Kirn, Thomas J.; Westblade, Lars F.; Humphries, Romney

2017-01-01

ABSTRACT As part of the American Society for Microbiology (ASM) Evidence-Based Laboratory Medicine Practice Guidelines Committee of the Professional Practice Committee, an ad hoc committee was formed in 2014 to assess guidelines published by the committee using an assessment tool, Appraisal of Guidelines for Research Evaluation II (AGREE II). The AGREE II assessment helps reviewers determine whether published guidelines are robust, transparent, and clear in presenting practice recommendations in a standardized manner. Identifying strengths and weaknesses of practice guidelines by ad hoc assessments helps with improving future guidelines through the participation of key stakeholders. This minireview describes the development of the ad hoc committee and results from their review of several ASM best practices guidelines and a non-ASM practice guideline from the Emergency Nurses Association. PMID:28835476

Report of the Army Scientific Advisory Panel AD HOC Group for Logistics and Research and Development

DTIC Science & Technology

1975-01-01

where the Group met with the commanding officers and staff of the Army Logistics Management Center (ALMC) and the Army Logistics Center (ALOGC...has been completad; i.e., retrospectively, and a new program being con- sidered . It is our understanding that the Army Logistics Management Center

Canadian Mathematics Education Study Group = Groupe Canadien d'etude en didactique des mathematiques. Proceedings of the 1993 Annual Meeting (York, Ontario, Canada, May 28-June 1, 1993).

ERIC Educational Resources Information Center

Quigley, Martyn, Ed.

These proceedings contain papers presented at the 1993 annual meeting of the Canadian Mathematics Education Study Group. Papers are presented in four sections: (1) invited lectures; (2) working groups; (3) topic groups; and (4) ad hoc groups. Papers include: (1) "What is a Square Root? A Study of Geometrical Representation in Different…

Canadian Mathematics Education Study Group = Groupe Canadien d'etude en didactique des mathematiques. Proceedings of the 1994 Annual Meeting (Regina, Saskatchewan, Canada, June 3-7, 1994).

ERIC Educational Resources Information Center

Quigley, Martyn, Ed.

These proceedings contain papers from the 1994 annual meeting of the Canadian Mathematics Education Study Group. Papers are divided into the following sections: (1) invited lectures; (2) working groups; (3) topic groups; (4) ad hoc groups; and (5) reports on ICMI (International Committee on Mathematical Instruction) studies. Papers include: (1)…

Energy Efficient and QoS sensitive Routing Protocol for Ad Hoc Networks

NASA Astrophysics Data System (ADS)

Saeed Tanoli, Tariq; Khalid Khan, Muhammad

2013-12-01

Efficient routing is an important part of wireless ad hoc networks. Since in ad hoc networks we have limited resources, there are many limitations like bandwidth, battery consumption, and processing cycle etc. Reliability is also necessary since there is no allowance for invalid or incomplete information (and expired data is useless). There are various protocols that perform routing by considering one parameter but ignoring other parameters. In this paper we present a protocol that finds route on the basis of bandwidth, energy and mobility of the nodes participating in the communication.

Global Coverage from Ad-Hoc Constellations in Rideshare Orbits

NASA Technical Reports Server (NTRS)

Ellis, Armin; Mercury, Michael; Brown, Shannon

2012-01-01

A promising area of small satellite development is in providing higher temporal resolution than larger satellites. Traditional constellations have required specific orbits and dedicated launch vehicles. In this paper we discuss an alternative architecture in which the individual elements of the constellation are launched as rideshare opportunities. We compare the coverage of such an ad-hoc constellation with more traditional constellations. Coverage analysis is based on actual historical data from rideshare opportunities. Our analysis includes ground coverage and temporal revisits for Polar, Tropics, Temperate, and Global regions, comparing ad-hoc and Walker constellation.

A Computational Method to Determine Glucose Infusion Rates for Isoglycemic Intravenous Glucose Infusion Study.

PubMed

Choi, Karam; Lee, Jung Chan; Oh, Tae Jung; Kim, Myeungseon; Kim, Hee Chan; Cho, Young Min; Kim, Sungwan

2016-01-01

The results of the isoglycemic intravenous glucose infusion (IIGI) study need to mimic the dynamic glucose profiles during the oral glucose tolerance test (OGTT) to accurately calculate the incretin effect. The glucose infusion rates during IIGI studies have historically been determined by experienced research personnel using the manual ad-hoc method. In this study, a computational method was developed to automatically determine the infusion rates for IIGI study based on a glucose-dynamics model. To evaluate the computational method, 18 subjects with normal glucose tolerance underwent a 75 g OGTT. One-week later, Group 1 (n = 9) and Group 2 (n = 9) underwent IIGI studies using the ad-hoc method and the computational method, respectively. Both methods were evaluated using correlation coefficient, mean absolute relative difference (MARD), and root mean square error (RMSE) between the glucose profiles from the OGTT and the IIGI study. The computational method exhibited significantly higher correlation (0.95 ± 0.03 versus 0.86 ± 0.10, P = 0.019), lower MARD (8.72 ± 1.83% versus 13.11 ± 3.66%, P = 0.002), and lower RMSE (10.33 ± 1.99 mg/dL versus 16.84 ± 4.43 mg/dL, P = 0.002) than the ad-hoc method. The computational method can facilitate IIGI study, and enhance its accuracy and stability. Using this computational method, a high-quality IIGI study can be accomplished without the need for experienced personnel.

Dynamic Key Management Schemes for Secure Group Access Control Using Hierarchical Clustering in Mobile Ad Hoc Networks

NASA Astrophysics Data System (ADS)

Tsaur, Woei-Jiunn; Pai, Haw-Tyng

2008-11-01

The applications of group computing and communication motivate the requirement to provide group access control in mobile ad hoc networks (MANETs). The operation in MANETs' groups performs a decentralized manner and accommodated membership dynamically. Moreover, due to lack of centralized control, MANETs' groups are inherently insecure and vulnerable to attacks from both within and outside the groups. Such features make access control more challenging in MANETs. Recently, several researchers have proposed group access control mechanisms in MANETs based on a variety of threshold signatures. However, these mechanisms cannot actually satisfy MANETs' dynamic environments. This is because the threshold-based mechanisms cannot be achieved when the number of members is not up to the threshold value. Hence, by combining the efficient elliptic curve cryptosystem, self-certified public key cryptosystem and secure filter technique, we construct dynamic key management schemes based on hierarchical clustering for securing group access control in MANETs. Specifically, the proposed schemes can constantly accomplish secure group access control only by renewing the secure filters of few cluster heads, when a cluster head joins or leaves a cross-cluster. In such a new way, we can find that the proposed group access control scheme can be very effective for securing practical applications in MANETs.

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

Ahn, Gail-Joon

The project seeks an innovative framework to enable users to access and selectively share resources in distributed environments, enhancing the scalability of information sharing. We have investigated secure sharing & assurance approaches for ad-hoc collaboration, focused on Grids, Clouds, and ad-hoc network environments.

Assessing Clinical Microbiology Practice Guidelines: American Society for Microbiology Ad Hoc Committee on Evidence-Based Laboratory Medicine Practice Guidelines Assessment.

PubMed

Nachamkin, Irving; Kirn, Thomas J; Westblade, Lars F; Humphries, Romney

2017-11-01

As part of the American Society for Microbiology (ASM) Evidence-Based Laboratory Medicine Practice Guidelines Committee of the Professional Practice Committee, an ad hoc committee was formed in 2014 to assess guidelines published by the committee using an assessment tool, Appraisal of Guidelines for Research Evaluation II (AGREE II). The AGREE II assessment helps reviewers determine whether published guidelines are robust, transparent, and clear in presenting practice recommendations in a standardized manner. Identifying strengths and weaknesses of practice guidelines by ad hoc assessments helps with improving future guidelines through the participation of key stakeholders. This minireview describes the development of the ad hoc committee and results from their review of several ASM best practices guidelines and a non-ASM practice guideline from the Emergency Nurses Association. Copyright © 2017 American Society for Microbiology.

Technologies for network-centric C4ISR

NASA Astrophysics Data System (ADS)

Dunkelberger, Kirk A.

2003-07-01

Three technologies form the heart of any network-centric command, control, communication, intelligence, surveillance, and reconnaissance (C4ISR) system: distributed processing, reconfigurable networking, and distributed resource management. Distributed processing, enabled by automated federation, mobile code, intelligent process allocation, dynamic multiprocessing groups, check pointing, and other capabilities creates a virtual peer-to-peer computing network across the force. Reconfigurable networking, consisting of content-based information exchange, dynamic ad-hoc routing, information operations (perception management) and other component technologies forms the interconnect fabric for fault tolerant inter processor and node communication. Distributed resource management, which provides the means for distributed cooperative sensor management, foe sensor utilization, opportunistic collection, symbiotic inductive/deductive reasoning and other applications provides the canonical algorithms for network-centric enterprises and warfare. This paper introduces these three core technologies and briefly discusses a sampling of their component technologies and their individual contributions to network-centric enterprises and warfare. Based on the implied requirements, two new algorithms are defined and characterized which provide critical building blocks for network centricity: distributed asynchronous auctioning and predictive dynamic source routing. The first provides a reliable, efficient, effective approach for near-optimal assignment problems; the algorithm has been demonstrated to be a viable implementation for ad-hoc command and control, object/sensor pairing, and weapon/target assignment. The second is founded on traditional dynamic source routing (from mobile ad-hoc networking), but leverages the results of ad-hoc command and control (from the contributed auctioning algorithm) into significant increases in connection reliability through forward prediction. Emphasis is placed on the advantages gained from the closed-loop interaction of the multiple technologies in the network-centric application environment.

Validity of using ad hoc methods to analyze secondary traits in case-control association studies.

PubMed

Yung, Godwin; Lin, Xihong

2016-12-01

Case-control association studies often collect from their subjects information on secondary phenotypes. Reusing the data and studying the association between genes and secondary phenotypes provide an attractive and cost-effective approach that can lead to discovery of new genetic associations. A number of approaches have been proposed, including simple and computationally efficient ad hoc methods that ignore ascertainment or stratify on case-control status. Justification for these approaches relies on the assumption of no covariates and the correct specification of the primary disease model as a logistic model. Both might not be true in practice, for example, in the presence of population stratification or the primary disease model following a probit model. In this paper, we investigate the validity of ad hoc methods in the presence of covariates and possible disease model misspecification. We show that in taking an ad hoc approach, it may be desirable to include covariates that affect the primary disease in the secondary phenotype model, even though these covariates are not necessarily associated with the secondary phenotype. We also show that when the disease is rare, ad hoc methods can lead to severely biased estimation and inference if the true disease model follows a probit model instead of a logistic model. Our results are justified theoretically and via simulations. Applied to real data analysis of genetic associations with cigarette smoking, ad hoc methods collectively identified as highly significant (P<10-5) single nucleotide polymorphisms from over 10 genes, genes that were identified in previous studies of smoking cessation. © 2016 WILEY PERIODICALS, INC.

78 FR 17992 - Preparations for the International Telecommunication Union World Telecommunication Development...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-25

... DEPARTMENT OF STATE [Public Notice 8251] Preparations for the International Telecommunication Union World Telecommunication Development Conference (ITU WTDC 2014) SUMMARY: This notice announces... the activities of its ad hoc group for preparations for the ITU World Telecommunication Development...

7 CFR 3415.14 - Proposal review.

Code of Federal Regulations, 2013 CFR

2013-01-01

... BIOTECHNOLOGY RISK ASSESSMENT RESEARCH GRANTS PROGRAM Scientific Peer Review of Research Grant Applications...., relationship of application to announced program area). Proposals that do not fall within the guidelines as... officers or employees of the Department, the respective peer review group, and ad hoc reviewers, as...

7 CFR 3415.14 - Proposal review.

Code of Federal Regulations, 2014 CFR

2014-01-01

... BIOTECHNOLOGY RISK ASSESSMENT RESEARCH GRANTS PROGRAM Scientific Peer Review of Research Grant Applications...., relationship of application to announced program area). Proposals that do not fall within the guidelines as... officers or employees of the Department, the respective peer review group, and ad hoc reviewers, as...

7 CFR 3415.14 - Proposal review.

Code of Federal Regulations, 2012 CFR

2012-01-01

... BIOTECHNOLOGY RISK ASSESSMENT RESEARCH GRANTS PROGRAM Scientific Peer Review of Research Grant Applications...., relationship of application to announced program area). Proposals that do not fall within the guidelines as... officers or employees of the Department, the respective peer review group, and ad hoc reviewers, as...

Feeding the Preschool Child: Documents Issued by PAG Ad Hoc Working Group Meetings (1969-1975).

ERIC Educational Resources Information Center

United Nations Industrial Development Organization, Vienna (Austria).

This document contains six papers prepared between 1969 and 1975 by the Protein-Calorie Advisory Group (PAG) of the United Nations on topics related to the feeding of preschool children in underdeveloped countries. Among the topics covered: (1) nutrition in utero; (2) nutritional aspects of breastfeeding; (3) infant mortality rates as indicators…

Effects of Verbal Behavior within Curriculum Development Committees on the Curriculum Product.

ERIC Educational Resources Information Center

Talmage, Harriet

An attempt was made to ascertain what type of verbal interaction behavior manifested by a group given a problem in curriculum development affects the quality of the product. Thirty ad hoc groups, selected randomly, were given curriculum development tasks to solve. Curriculum Guide Form (CGF) and Bales' Interaction Process Analysis (IPA) were used…

The Origin of the United States Security Commitment to the Republic of Korea

DTIC Science & Technology

1987-06-01

and war and of the effect of these objectives on our strategic plans, in the light of the probable fission bomb capability and possible thermonuclear ... bomb capability of the Soviet Union. 226 A special ad hoc working group was formed under Nitze to conduct this study. This group took advantage of the

78 FR 47675 - Pacific Fishery Management Council; Public Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-06

... Pacific Fishery Management Council's (Pacific Council) Ad Hoc Groundfish Electronic Monitoring Committee and Ad Hoc Trawl Groundfish Electronic Monitoring Technical Advisory Committee (GEM Committees) will... meeting is to discuss and develop potential alternatives for electronic monitoring (EM) for vessels...

Using expert opinion to quantify accuracy and reliability of nondestructive evaluation on bridges.

DOT National Transportation Integrated Search

2015-08-01

Bridge inspection is an important phase in bridge management. In 2009, a joint American Society of Civil : Engineers Structural Engineering Institute and AASHTO Ad-Hoc group was created to identify the issues : in bridge safety and to study current b...

16 CFR 1018.4 - Applicability.

Code of Federal Regulations, 2012 CFR

2012-01-01

... organizations: (1) Any local civic group whose primary function is that of rendering a public service with... non-statutory) subject to the jurisdiction of the Commission. This part also shall apply to ad hoc advisory committees and non-Commission established advisory committees when they are performing advisory...

16 CFR 1018.4 - Applicability.

Code of Federal Regulations, 2014 CFR

2014-01-01

... organizations: (1) Any local civic group whose primary function is that of rendering a public service with... non-statutory) subject to the jurisdiction of the Commission. This part also shall apply to ad hoc advisory committees and non-Commission established advisory committees when they are performing advisory...

16 CFR 1018.4 - Applicability.

Code of Federal Regulations, 2011 CFR

2011-01-01

... organizations: (1) Any local civic group whose primary function is that of rendering a public service with... non-statutory) subject to the jurisdiction of the Commission. This part also shall apply to ad hoc advisory committees and non-Commission established advisory committees when they are performing advisory...

16 CFR § 1018.4 - Applicability.

Code of Federal Regulations, 2013 CFR

2013-01-01

... organizations: (1) Any local civic group whose primary function is that of rendering a public service with... non-statutory) subject to the jurisdiction of the Commission. This part also shall apply to ad hoc advisory committees and non-Commission established advisory committees when they are performing advisory...

16 CFR 1018.4 - Applicability.

Code of Federal Regulations, 2010 CFR

2010-01-01

... organizations: (1) Any local civic group whose primary function is that of rendering a public service with... non-statutory) subject to the jurisdiction of the Commission. This part also shall apply to ad hoc advisory committees and non-Commission established advisory committees when they are performing advisory...

Efficient routing for safety applications in vehicular networks.

DOT National Transportation Integrated Search

2009-03-01

Vehicular ad hoc networks have received a lot of attention in recent years. This attention is due to two reasons. : First and foremost, there are a number of real-life applications that become possible in the presence of : such an ad-hoc infrastructu...

A Multi-User Game-Theoretical Multipath Routing Protocol to Send Video-Warning Messages over Mobile Ad Hoc Networks.

PubMed

Mezher, Ahmad Mohamad; Igartua, Mónica Aguilar; de la Cruz Llopis, Luis J; Pallarès Segarra, Esteve; Tripp-Barba, Carolina; Urquiza-Aguiar, Luis; Forné, Jordi; Sanvicente Gargallo, Emilio

2015-04-17

The prevention of accidents is one of the most important goals of ad hoc networks in smart cities. When an accident happens, dynamic sensors (e.g., citizens with smart phones or tablets, smart vehicles and buses, etc.) could shoot a video clip of the accident and send it through the ad hoc network. With a video message, the level of seriousness of the accident could be much better evaluated by the authorities (e.g., health care units, police and ambulance drivers) rather than with just a simple text message. Besides, other citizens would be rapidly aware of the incident. In this way, smart dynamic sensors could participate in reporting a situation in the city using the ad hoc network so it would be possible to have a quick reaction warning citizens and emergency units. The deployment of an efficient routing protocol to manage video-warning messages in mobile Ad hoc Networks (MANETs) has important benefits by allowing a fast warning of the incident, which potentially can save lives. To contribute with this goal, we propose a multipath routing protocol to provide video-warning messages in MANETs using a novel game-theoretical approach. As a base for our work, we start from our previous work, where a 2-players game-theoretical routing protocol was proposed to provide video-streaming services over MANETs. In this article, we further generalize the analysis made for a general number of N players in the MANET. Simulations have been carried out to show the benefits of our proposal, taking into account the mobility of the nodes and the presence of interfering traffic. Finally, we also have tested our approach in a vehicular ad hoc network as an incipient start point to develop a novel proposal specifically designed for VANETs.

Specialist availability in emergencies: contributions of response times and the use of ad hoc coverage in New York State.

PubMed

Rabin, Elaine; Patrick, Lisa

2016-04-01

Nationwide, hospitals struggle to maintain specialist on-call coverage for emergencies. We seek to further understand the issue by examining reliability of scheduled coverage and the role of ad hoc coverage when none is scheduled. An anonymous electronic survey of all emergency department (ED) directors of a large state. Overall and for 10 specialties, respondents were asked to estimate on-call coverage extent and "reliability" (frequency of emergency response in a clinically useful time frame: 2 hours), and use and effect of ad hoc emergency coverage to fill gaps. Descriptive statistics were performed using Fisher exact and Wilcoxon sign rank tests for significance. Contact information was obtained for 125 of 167 ED directors. Sixty responded (48%), representing 36% of EDs. Forty-six percent reported full on-call coverage scheduled for all specialties. Forty-six percent reported consistent reliability. Coverage and reliability were strongly related (P<.01; 33% reported both), and larger ED volume correlated with both (P<.01). Ninety percent of hospitals that had gaps in either employed ad hoc coverage, significantly improving coverage for 8 of 10 specialties. For all but 1 specialty, more than 20% of hospitals reported that specialists are "Never", "Rarely" or "Sometimes" reliable (more than 50% for cardiovascular surgery, hand surgery and ophthalmology). Significant holes in scheduled on-call specialist coverage are compounded by frequent unreliability of on-call specialists, but partially ameliorated by ad hoc specialist coverage. Regionalization may help because a 2-tiered system may exist: larger hospitals have more complete, reliable coverage. Better understanding of specialists' willingness to treat emergencies ad hoc without taking formal call will suggest additional remedies. Copyright © 2015 Elsevier Inc. All rights reserved.

78 FR 8145 - Sequence 24 Findings of the EISA 436(h) Ad-Hoc Review Group on Green Building Certification Systems

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-05

... Group are seeking public input regarding possible approaches GSA may take in fulfilling its requirement... comprehensive and environmentally- sound approach to the certification of green Federal buildings. GSA is using... comments by one of the methods shown below on or before 60 days after publication in the Federal Register...

Auto-Configuration Protocols in Mobile Ad Hoc Networks

PubMed Central

Villalba, Luis Javier García; Matesanz, Julián García; Orozco, Ana Lucila Sandoval; Díaz, José Duván Márquez

2011-01-01

The TCP/IP protocol allows the different nodes in a network to communicate by associating a different IP address to each node. In wired or wireless networks with infrastructure, we have a server or node acting as such which correctly assigns IP addresses, but in mobile ad hoc networks there is no such centralized entity capable of carrying out this function. Therefore, a protocol is needed to perform the network configuration automatically and in a dynamic way, which will use all nodes in the network (or part thereof) as if they were servers that manage IP addresses. This article reviews the major proposed auto-configuration protocols for mobile ad hoc networks, with particular emphasis on one of the most recent: D2HCP. This work also includes a comparison of auto-configuration protocols for mobile ad hoc networks by specifying the most relevant metrics, such as a guarantee of uniqueness, overhead, latency, dependency on the routing protocol and uniformity. PMID:22163814

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.

MWAHCA: a multimedia wireless ad hoc cluster architecture.

PubMed

Diaz, Juan R; Lloret, Jaime; Jimenez, Jose M; Sendra, Sandra

2014-01-01

Wireless Ad hoc networks provide a flexible and adaptable infrastructure to transport data over a great variety of environments. Recently, real-time audio and video data transmission has been increased due to the appearance of many multimedia applications. One of the major challenges is to ensure the quality of multimedia streams when they have passed through a wireless ad hoc network. It requires adapting the network architecture to the multimedia QoS requirements. In this paper we propose a new architecture to organize and manage cluster-based ad hoc networks in order to provide multimedia streams. Proposed architecture adapts the network wireless topology in order to improve the quality of audio and video transmissions. In order to achieve this goal, the architecture uses some information such as each node's capacity and the QoS parameters (bandwidth, delay, jitter, and packet loss). The architecture splits the network into clusters which are specialized in specific multimedia traffic. The real system performance study provided at the end of the paper will demonstrate the feasibility of the proposal.

Schools Can Provide Help for the Children of Divorce.

ERIC Educational Resources Information Center

Holzman, Terry

1984-01-01

Since the mid-1970s, Newton, Massachusetts, schools have developed support groups and curricular offerings to help children of divorced parents. Newton's Ad-Hoc Committee on Separation and Divorce, developed under the leadership of John Cullinane, now serves as a systemwide clearinghouse for teacher resources. (JBM)

Multicasting in Wireless Communications (Ad-Hoc Networks): Comparison against a Tree-Based Approach

NASA Astrophysics Data System (ADS)

Rizos, G. E.; Vasiliadis, D. C.

2007-12-01

We examine on-demand multicasting in ad hoc networks. The Core Assisted Mesh Protocol (CAMP) is a well-known protocol for multicast routing in ad-hoc networks, generalizing the notion of core-based trees employed for internet multicasting into multicast meshes that have much richer connectivity than trees. On the other hand, wireless tree-based multicast routing protocols use much simpler structures for determining route paths, using only parent-child relationships. In this work, we compare the performance of the CAMP protocol against the performance of wireless tree-based multicast routing protocols, in terms of two important factors, namely packet delay and ratio of dropped packets.

Gemini: Extending Information Management for Real Time Tactical Environments

DTIC Science & Technology

2008-03-01

Mobile,  Ad ‐ Hoc  Networks.......................................................................................................49  8.4  Wired...networks, such as  wireless  ad ‐ hoc  networks. This paper looked into the operating environments expected to be available to  Unmanned Aircraft Systems...decentralized,  ad ‐ hoc   networks. The total peering capability of these networks may be very large. And, each network or access  point may carry restrictions; for

Curriculum Integration Using Enterprise Resource Planning: An Integrative Case Approach

ERIC Educational Resources Information Center

Cannon, David M.; Klein, Helen A; Koste, Lori L.; Magal, Simha R.

2004-01-01

Efforts to achieve greater curriculum integration in schools of business have included team teaching, student group projects, multidisciplinary cases, and, more recently, the use of enterprise resource planning (ERP) systems. Although these approaches are beneficial, they tend to be implemented on an ad hoc basis rather than through curriculum…

Analysis performed in support of the Ad-Hoc Working Group of RTCA SC-159 on RAIM/FDE issues

DOT National Transportation Integrated Search

2002-01-01

In 1999, the FAA requested that RTCA SC-159 address one of the recommendations from the study performed by the Johns Hopkins University (JHU) Applied Physics Lab (APL) on the use of GPS and augmented GPS for aviation applications. This recommendation...

Freedom of Speech Newsletter, September, 1975.

ERIC Educational Resources Information Center

Allen, Winfred G., Jr., Ed.

The Freedom of Speech Newsletter is the communication medium for the Freedom of Speech Interest Group of the Western Speech Communication Association. The newsletter contains such features as a statement of concern by the National Ad Hoc Committee Against Censorship; Reticence and Free Speech, an article by James F. Vickrey discussing the subtle…

A Regional Serials Program under National Serials Data Program Auspices: Discussion Paper Prepared for Ad Hoc Serials Discussion Group

ERIC Educational Resources Information Center

Grosch, Audrey N.

1973-01-01

A regionally organized program for serials bibliography is proposed because of the large volume of complex data needing control and the many purposes to which the data can be put in support of regional or local needs. (2 references) (Author)

Ad Hoc Rural Regionalism

ERIC Educational Resources Information Center

Hamin, Elisabeth M.; Marcucci, Daniel J.

2008-01-01

A new regionalism has been much documented and researched for metropolitan areas; this article documents that there is a new rural regionalism as well. In the United States, these groups appear most likely to emerge in areas that are challenged by outcomes characterizing globalization's effects on the rural condition: namely, exurban or…

BLAST FURNACE CAST HOUSE EMISSION CONTROL TECHNOLOGY ASSESSMENT

EPA Science Inventory

The study describes the state-of-the-art of controlling fumes escaping from blast furnace cast houses. Background information is based on: a study of existing literature; visits to blast furnaces in the U.S., Japan, and Europe; meetings with an ad hoc group of experienced blast f...

Places for Pedagogies, Pedagogies for Places

ERIC Educational Resources Information Center

Duhn, Iris

2012-01-01

Working with an understanding of assemblage as the ad hoc groupings of vibrant materials and elements, this article argues that conceptualizing place as an assemblage opens possibilities for bridging the gap between subjects and objects that continue to structure pedagogy. Considering "place" as an assemblage of humans and their multiple…

External and Internal Sport Motivations of Young Adults

ERIC Educational Resources Information Center

Bollok, Sandor; Takacs, Johanna; Kalmar, Zsuzsanna; Dobay, Beata

2011-01-01

Study aim: To determine and evaluate the spectrum of sport motivation of young adults. Material and methods: A group of 600 subjects, aged 17-19 years, participated in the study. An "ad hoc" questionnaire was applied to assess the 4 motivational factors: competition and success-oriented motivation, external accommodation, physical…

Cooperative Education and the Academy. and Response to the Preliminary Report of the Ad Hoc Committee on Cooperative Education and the Curriculum.

ERIC Educational Resources Information Center

Heinemann, Harry N.; And Others

1988-01-01

Two articles describe the final report submitted by the Ad Hoc Committee on Cooperative Education and the Curriculum to the Cooperative Education Association and the reaction to that report by the person who established the committee. (JOW)

78 FR 10564 - Proposed Modification of Class B Airspace; Minneapolis, MN

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-14

... about the proposed design. The Ad Hoc Committee was chaired by the Minnesota Soaring Club representative... Minnesota Soaring Club and Stanton Sport Aviation operations. The Ad Hoc Committee's report provided to the... indicate the proposed modifications would impact the Minnesota Soaring Club and Stanton Sport Aviation...

What Is the Problem of Ad Hoc Hypotheses?

ERIC Educational Resources Information Center

Bamford, Greg

1999-01-01

Philosophers' attempts to convincingly explicate the received view of an ad hoc hypothesis--that it accounts for only the observations it was designed to account for--have been unsuccessful. Familiar and firmer criteria for evaluating the hypotheses or modified theories so classified are characteristically available. Contains 41 references.…

Providing Location Security in Vehicular Ad Hoc Networks

ERIC Educational Resources Information Center

Yan, Gongjun

2010-01-01

Location is fundamental information in Vehicular Ad-hoc Networks (VANETs). Almost all VANET applications rely on location information. Therefore it is of importance to ensure location information integrity, meaning that location information is original (from the generator), correct (not bogus or fabricated) and unmodified (value not changed). We…

The Use of English as Ad Hoc Institutional Standard in the Belgian Asylum Interview

ERIC Educational Resources Information Center

Maryns, Katrijn

2017-01-01

In institutional settings of globalization, labelled languages are generally preferred over multilingual repertoires and mobile language resources. Drawing on linguistic-ethnographic analysis of the way English is treated as an invariable "ad hoc" idiom in the Belgian asylum interview, this article demonstrates how institutional measures…

Canadian Mathematics Education Study Group = Groupe Canadien d'Etude en Didactique des Mathematiques. Proceedings of the Annual Meeting (25th, Edmonton, Alberta, Canada, May 25-29, 2001).

ERIC Educational Resources Information Center

Simmt, Elaine, Ed.; Davis, Brent, Ed.

2001-01-01

This document contains the proceedings of the 2001 annual meeting of the Canadian Mathematics Education Study Group (CMESG) held at the University of Alberta, May 25-39, 2000. The proceedings consist of two plenary lectures, four working groups, five topic sessions, new Ph.D. reports, an AD Hoc Session, and panel discussions. Papers include: (1)…

Implementing Machine Learning in the PCWG Tool

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

Clifton, Andrew; Ding, Yu; Stuart, Peter

The Power Curve Working Group (www.pcwg.org) is an ad-hoc industry-led group to investigate the performance of wind turbines in real-world conditions. As part of ongoing experience-sharing exercises, machine learning has been proposed as a possible way to predict turbine performance. This presentation provides some background information about machine learning and how it might be implemented in the PCWG exercises.

Spontaneous Group Learning in Ambient Learning Environments

NASA Astrophysics Data System (ADS)

Bick, Markus; Jughardt, Achim; Pawlowski, Jan M.; Veith, Patrick

Spontaneous Group Learning is a concept to form and facilitate face-to-face, ad-hoc learning groups in collaborative settings. We show how to use Ambient Intelligence to identify, support, and initiate group processes. Learners' positions are determined by widely used technologies, e.g., Bluetooth and WLAN. As a second step, learners' positions, tasks, and interests are visualized. Finally, a group process is initiated supported by relevant documents and services. Our solution is a starting point to develop new didactical solutions for collaborative processes.

An Ad-Hoc Adaptive Pilot Model for Pitch Axis Gross Acquisition Tasks

NASA Technical Reports Server (NTRS)

Hanson, Curtis E.

2012-01-01

An ad-hoc algorithm is presented for real-time adaptation of the well-known crossover pilot model and applied to pitch axis gross acquisition tasks in a generic fighter aircraft. Off-line tuning of the crossover model to human pilot data gathered in a fixed-based high fidelity simulation is first accomplished for a series of changes in aircraft dynamics to provide expected values for model parameters. It is shown that in most cases, for this application, the traditional crossover model can be reduced to a gain and a time delay. The ad-hoc adaptive pilot gain algorithm is shown to have desirable convergence properties for most types of changes in aircraft dynamics.

Anomaly Detection Techniques for Ad Hoc Networks

ERIC Educational Resources Information Center

Cai, Chaoli

2009-01-01

Anomaly detection is an important and indispensable aspect of any computer security mechanism. Ad hoc and mobile networks consist of a number of peer mobile nodes that are capable of communicating with each other absent a fixed infrastructure. Arbitrary node movements and lack of centralized control make them vulnerable to a wide variety of…

MAC Protocol for Ad Hoc Networks Using a Genetic Algorithm

PubMed Central

Elizarraras, Omar; Panduro, Marco; Méndez, Aldo L.

2014-01-01

The problem of obtaining the transmission rate in an ad hoc network consists in adjusting the power of each node to ensure the signal to interference ratio (SIR) and the energy required to transmit from one node to another is obtained at the same time. Therefore, an optimal transmission rate for each node in a medium access control (MAC) protocol based on CSMA-CDMA (carrier sense multiple access-code division multiple access) for ad hoc networks can be obtained using evolutionary optimization. This work proposes a genetic algorithm for the transmission rate election considering a perfect power control, and our proposition achieves improvement of 10% compared with the scheme that handles the handshaking phase to adjust the transmission rate. Furthermore, this paper proposes a genetic algorithm that solves the problem of power combining, interference, data rate, and energy ensuring the signal to interference ratio in an ad hoc network. The result of the proposed genetic algorithm has a better performance (15%) compared to the CSMA-CDMA protocol without optimizing. Therefore, we show by simulation the effectiveness of the proposed protocol in terms of the throughput. PMID:25140339

MWAHCA: A Multimedia Wireless Ad Hoc Cluster Architecture

PubMed Central

Diaz, Juan R.; Jimenez, Jose M.; Sendra, Sandra

2014-01-01

Wireless Ad hoc networks provide a flexible and adaptable infrastructure to transport data over a great variety of environments. Recently, real-time audio and video data transmission has been increased due to the appearance of many multimedia applications. One of the major challenges is to ensure the quality of multimedia streams when they have passed through a wireless ad hoc network. It requires adapting the network architecture to the multimedia QoS requirements. In this paper we propose a new architecture to organize and manage cluster-based ad hoc networks in order to provide multimedia streams. Proposed architecture adapts the network wireless topology in order to improve the quality of audio and video transmissions. In order to achieve this goal, the architecture uses some information such as each node's capacity and the QoS parameters (bandwidth, delay, jitter, and packet loss). The architecture splits the network into clusters which are specialized in specific multimedia traffic. The real system performance study provided at the end of the paper will demonstrate the feasibility of the proposal. PMID:24737996

Distributed generation of shared RSA keys in mobile ad hoc networks

NASA Astrophysics Data System (ADS)

Liu, Yi-Liang; Huang, Qin; Shen, Ying

2005-12-01

Mobile Ad Hoc Networks is a totally new concept in which mobile nodes are able to communicate together over wireless links in an independent manner, independent of fixed physical infrastructure and centralized administrative infrastructure. However, the nature of Ad Hoc Networks makes them very vulnerable to security threats. Generation and distribution of shared keys for CA (Certification Authority) is challenging for security solution based on distributed PKI(Public-Key Infrastructure)/CA. The solutions that have been proposed in the literature and some related issues are discussed in this paper. The solution of a distributed generation of shared threshold RSA keys for CA is proposed in the present paper. During the process of creating an RSA private key share, every CA node only has its own private security. Distributed arithmetic is used to create the CA's private share locally, and that the requirement of centralized management institution is eliminated. Based on fully considering the Mobile Ad Hoc network's characteristic of self-organization, it avoids the security hidden trouble that comes by holding an all private security share of CA, with which the security and robustness of system is enhanced.

Post Hoc Analyses of ApoE Genotype-Defined Subgroups in Clinical Trials.

PubMed

Kennedy, Richard E; Cutter, Gary R; Wang, Guoqiao; Schneider, Lon S

2016-01-01

Many post hoc analyses of clinical trials in Alzheimer's disease (AD) and mild cognitive impairment (MCI) are in small Phase 2 trials. Subject heterogeneity may lead to statistically significant post hoc results that cannot be replicated in larger follow-up studies. We investigated the extent of this problem using simulation studies mimicking current trial methods with post hoc analyses based on ApoE4 carrier status. We used a meta-database of 24 studies, including 3,574 subjects with mild AD and 1,171 subjects with MCI/prodromal AD, to simulate clinical trial scenarios. Post hoc analyses examined if rates of progression on the Alzheimer's Disease Assessment Scale-cognitive (ADAS-cog) differed between ApoE4 carriers and non-carriers. Across studies, ApoE4 carriers were younger and had lower baseline scores, greater rates of progression, and greater variability on the ADAS-cog. Up to 18% of post hoc analyses for 18-month trials in AD showed greater rates of progression for ApoE4 non-carriers that were statistically significant but unlikely to be confirmed in follow-up studies. The frequency of erroneous conclusions dropped below 3% with trials of 100 subjects per arm. In MCI, rates of statistically significant differences with greater progression in ApoE4 non-carriers remained below 3% unless sample sizes were below 25 subjects per arm. Statistically significant differences for ApoE4 in post hoc analyses often reflect heterogeneity among small samples rather than true differential effect among ApoE4 subtypes. Such analyses must be viewed cautiously. ApoE genotype should be incorporated into the design stage to minimize erroneous conclusions.

Research Opportunities in Nutrition and Metabolism in Space

NASA Technical Reports Server (NTRS)

Altman, Philip L. (Editor); Fisher, Kenneth D. (Editor)

1986-01-01

The objectives of the Life Sciences Research Office (LSRO) study on nutrient requirements for meeting metabolic needs in manned space flights are as follows: review extant knowledge on the subject; identify significant gaps in knowledge; formulate suggestions for possible research; and produce a documented report of the foregoing items that can be used for program planning. In accordance with NASA's request for this study, the report focuses on issues of nutrition and metabolism that relate primarily to the contemplated United States Space Station, secondarily to the Shuttle Program as an orbital test bed for operational studies, and incidentally to scenarios for future long-term space flights. Members of the LSRO ad hoc Working Group on Nutrition and Metabolism were provided with pertinent articles and summaries on the subject. At the meeting of the Working Group, presentations were made by NASA Headquarters program staff on past experiences relative to space-flight nutrition and metabolism, as well as scenarios for future flights. The discussions of the ad hoc Working Group focused on the following: (1) metabolic needs related to work and exercise; (2) nutrients required to meet such needs; (3) food types, management, and records; and (4) nutritional amelioration or prevention of space-related physiological and behavioral changes.

Monitoring and tracing of critical software systems: State of the work and project definition

DTIC Science & Technology

2008-12-01

analysis, troubleshooting and debugging. Some of these subsystems already come with ad hoc tracers for events like wireless connections or SCSI disk... SQLite ). Additional synthetic events (e.g. states) are added to the database. The database thus consists in contexts (process, CPU, state), event...capability on a [operating] system-by-system basis. Additionally, the mechanics of querying the data in an ad - hoc manner outside the boundaries of the

Is heart transplantation after circulatory death compatible with the dead donor rule?

PubMed

Nair-Collins, Michael; Miller, Franklin G

2016-05-01

Dalle Ave et al (2016) provide a valuable overview of several protocols for heart transplantation after circulatory death. However, their analysis of the compatibility of heart donation after circulatory death (DCD) with the dead donor rule (DDR) is flawed. Their permanence-based criteria for death, which depart substantially from established law and bioethics, are ad hoc and unfounded. Furthermore, their analysis is self-defeating, because it undercuts the central motivation for DDR as both a legal and a moral constraint, rendering the DDR vacuous and trivial. Rather than devise new and ad hoc criteria for death for the purpose of rendering DCD nominally consistent with DDR, we contend that the best approach is to explicitly abandon DDR. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

A Multi-User Game-Theoretical Multipath Routing Protocol to Send Video-Warning Messages over Mobile Ad Hoc Networks

PubMed Central

Mezher, Ahmad Mohamad; Igartua, Mónica Aguilar; de la Cruz Llopis, Luis J.; Segarra, Esteve Pallarès; Tripp-Barba, Carolina; Urquiza-Aguiar, Luis; Forné, Jordi; Gargallo, Emilio Sanvicente

2015-01-01

The prevention of accidents is one of the most important goals of ad hoc networks in smart cities. When an accident happens, dynamic sensors (e.g., citizens with smart phones or tablets, smart vehicles and buses, etc.) could shoot a video clip of the accident and send it through the ad hoc network. With a video message, the level of seriousness of the accident could be much better evaluated by the authorities (e.g., health care units, police and ambulance drivers) rather than with just a simple text message. Besides, other citizens would be rapidly aware of the incident. In this way, smart dynamic sensors could participate in reporting a situation in the city using the ad hoc network so it would be possible to have a quick reaction warning citizens and emergency units. The deployment of an efficient routing protocol to manage video-warning messages in mobile Ad hoc Networks (MANETs) has important benefits by allowing a fast warning of the incident, which potentially can save lives. To contribute with this goal, we propose a multipath routing protocol to provide video-warning messages in MANETs using a novel game-theoretical approach. As a base for our work, we start from our previous work, where a 2-players game-theoretical routing protocol was proposed to provide video-streaming services over MANETs. In this article, we further generalize the analysis made for a general number of N players in the MANET. Simulations have been carried out to show the benefits of our proposal, taking into account the mobility of the nodes and the presence of interfering traffic.Finally, we also have tested our approach in a vehicular ad hoc network as an incipient start point to develop a novel proposal specifically designed for VANETs. PMID:25897496

Higher Education, Globalization and Economic Development in Virginia

ERIC Educational Resources Information Center

State Council of Higher Education for Virginia, 2010

2010-01-01

In early 2009, the State Council of Higher Education for Virginia (SCHEV) initiated an effort to assess the status of the Commonwealth's international education programs. A survey was distributed to the public and private institutions, focusing on critical aspects of contemporary international education programs as identified by an ad hoc group of…

Life Cycles of Ad Hoc Task Groups

DTIC Science & Technology

1983-10-01

Rick’s Cafe after work. . 25 Alexandra: You have connections? 26 Ken: Yes! ൣ Alexandra: You can be the industrial spy! (Pause) We don’t really need...with franchising --he could do a whole business strictly dealing with spare parts. We have to describe these packages and describe how to... (words

A glossary of selected meteorology terms. Final report

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

Not Available

1982-09-01

The atmospheric, oceanographic, nuclear, and electro-optical terminology contained in this publication was compiled by the Ad Hoc Glossary Committee of the Meteorology Group (MG) of the Range Commanders Council. Much of the material appearing in this glossary was developed using information from several U.S. Government publications and the Glossary of Meteorology.

Serbia and Montenegro: The Catalytic Effects of Higher Education

ERIC Educational Resources Information Center

Zindovic-Vukadinovic, Gordana

2004-01-01

Brain drain has been a long-lasting phenomenon. It existed in the former Yugoslavia, and was affected by various factors, from political through economic ones to the attractive offers for advanced studies and work in scientific institutions or firms in developed countries. Some ad-hoc analyses were made concerning individual groups or periods, but…

SPECS: Secure and Privacy Enhancing Communications Schemes for VANETs

NASA Astrophysics Data System (ADS)

Chim, T. W.; Yiu, S. M.; Hui, L. C. K.; Jiang, Zoe L.; Li, Victor O. K.

Vehicular ad hoc network (VANET) is an emerging type of networks which facilitates vehicles on roads to communicate for driving safety. The basic idea is to allow arbitrary vehicles to broadcast ad hoc messages (e.g. traffic accidents) to other vehicles. However, this raises the concern of security and privacy. Messages should be signed and verified before they are trusted while the real identity of vehicles should not be revealed, but traceable by authorized party. Existing solutions either rely heavily on a tamper-proof hardware device, or cannot satisfy the privacy requirement and do not have an effective message verification scheme. In this paper, we provide a software-based solution which makes use of only two shared secrets to satisfy the privacy requirement and gives lower message overhead and at least 45% higher successful rate than previous solutions in the message verification phase using the bloom filter and the binary search techniques. We also provide the first group communication protocol to allow vehicles to authenticate and securely communicate with others in a group of known vehicles.

Medium Access Control Protocols for Cognitive Radio Ad Hoc Networks: A Survey

PubMed Central

Islam, A. K. M. Muzahidul; Baharun, Sabariah; Mansoor, Nafees

2017-01-01

New wireless network paradigms will demand higher spectrum use and availability to cope with emerging data-hungry devices. Traditional static spectrum allocation policies cause spectrum scarcity, and new paradigms such as Cognitive Radio (CR) and new protocols and techniques need to be developed in order to have efficient spectrum usage. Medium Access Control (MAC) protocols are accountable for recognizing free spectrum, scheduling available resources and coordinating the coexistence of heterogeneous systems and users. This paper provides an ample review of the state-of-the-art MAC protocols, which mainly focuses on Cognitive Radio Ad Hoc Networks (CRAHN). First, a description of the cognitive radio fundamental functions is presented. Next, MAC protocols are divided into three groups, which are based on their channel access mechanism, namely time-slotted protocol, random access protocol and hybrid protocol. In each group, a detailed and comprehensive explanation of the latest MAC protocols is presented, as well as the pros and cons of each protocol. A discussion on future challenges for CRAHN MAC protocols is included with a comparison of the protocols from a functional perspective. PMID:28926952

HumRRO Activities in Support of the Self-Pacing of Four U.S. Army TRADOC Programs of Instruction.

DTIC Science & Technology

1976-03-01

Quality of input is improving (more high school graduates), but is not as good as they would like. Entry i requirements are: an EL of 90; not color...MOS 64C); and Fielw Wireman (36K). HumRRO scientists inter- acted with proponent school staff and with members of the TP.ADOC/TMI ad hoc group to...continued... -Ad) specific responsibilities for accomplishing course conversion. Prior to making site visits to the Military Police School , Transportation

The U.S culture collection network lays the foundation for progress in preservation of valuable microbial resources

Treesearch

K. McCluskey; A. Alvarez; R. Bennett; D. Bokati; K. Boundy-Mills; D. D. Brown; C. T. Bull; M. Coffey; T. Dreaden; C. Duke; G. Dye; E. Ehmke; K. Eversole; K. Fenstermacher; D. Geiser; Jessie A. Glaeser; S. Greene; L. Gribble; M. P. Griffith; K. Hanser; R. Humber; B. W. Johnson; A. Kermode; M. Krichevsky; M. Laudon; J. Leach; J. Leslie; M. May; U. Melcher; D. Nobles; N. R. Fonseca; S. Robinson; M. Ryan; J. Scott; C. Silflow; A. Vidaver; K. M. Webb; J. E. Wertz; S. Yentsch; S. Zehr

2016-01-01

The U.S. Culture Collection Network was formed in 2012 by a group of culture collection scientists and stakeholders in order to continue the progress established previously through efforts of an ad hoc group. The network is supported by a Research Coordination Network grant from the U.S. National Science Foundation (NSF) and has the goals of promoting interaction among...

Ad Hoc working group on diurnal and semi-diurnal Earth Orientation variation.

NASA Astrophysics Data System (ADS)

Gipson, J. M.

2017-12-01

Diurnal and semi-diurnal Earth orientation ("HF-EOP") variation were detected in the early 1990s in SLR and VLBI data. Beginning in 1996 a model of HF-EOP variation based on ocean-tides derived from Topex data was included in the IERS standards. This model has not been updated since then with the exception of including libration for effects for polar motion (2003 IERS conventions) and UT1 (2010 IERS conventions). The accuracy of Space Geodesy has increased remarkably over the last 20 years and the 1996 IERS HF-EOP model is no longer adequate. At the conclusion of the 2017 GGOS/IERS Unified Analysis Workshop an ad hoc working group was formed including representatives of the IDS, IGS, ILRS, and IVS. The goal of the working group is to test several models of HF-EOP in the different space geodesy techniques and to make a recommendation to the IERS for the adoption of a new HF-EOP model. In this presentation I will give a summary of work on HF-EOP done to date by various scientists which demonstrate the inadequacy of the current IERS HF-EOP model. I will then describe the goals and the progress of the working group to date, with a preview of further work.

Commission 5: Documentation and Astronomical Data

NASA Astrophysics Data System (ADS)

Norris, Raymond P.; Ohishi, Masatoshi; Genova, Françoise; Grothkopf, Uta; Malkov, Oleg Yu.; Pence, William D.; Schmitz, Marion; Hanisch, Robert J.; Zhou, Xu

IAU Commission 5 deals with data management issues, and its working groups and task groups deal specifically with information handling, with data centres and networks, with technical aspects of collection, archiving, storage and dissemination of data, with designations and classification of astronomical objects, with library services, editorial policies, computer communications, ad hoc methodologies, and with various standards, reference frames, etc., FITS, astronomys Flexible Image Transport System, the major data exchange format, is controlled, maintained and updated by the Working Group FITS.

Identification and Forecasting in Mortality Models

PubMed Central

Nielsen, Jens P.

2014-01-01

Mortality models often have inbuilt identification issues challenging the statistician. The statistician can choose to work with well-defined freely varying parameters, derived as maximal invariants in this paper, or with ad hoc identified parameters which at first glance seem more intuitive, but which can introduce a number of unnecessary challenges. In this paper we describe the methodological advantages from using the maximal invariant parameterisation and we go through the extra methodological challenges a statistician has to deal with when insisting on working with ad hoc identifications. These challenges are broadly similar in frequentist and in Bayesian setups. We also go through a number of examples from the literature where ad hoc identifications have been preferred in the statistical analyses. PMID:24987729

Quantum load balancing in ad hoc networks

NASA Astrophysics Data System (ADS)

Hasanpour, M.; Shariat, S.; Barnaghi, P.; Hoseinitabatabaei, S. A.; Vahid, S.; Tafazolli, R.

2017-06-01

This paper presents a novel approach in targeting load balancing in ad hoc networks utilizing the properties of quantum game theory. This approach benefits from the instantaneous and information-less capability of entangled particles to synchronize the load balancing strategies in ad hoc networks. The quantum load balancing (QLB) algorithm proposed by this work is implemented on top of OLSR as the baseline routing protocol; its performance is analyzed against the baseline OLSR, and considerable gain is reported regarding some of the main QoS metrics such as delay and jitter. Furthermore, it is shown that QLB algorithm supports a solid stability gain in terms of throughput which stands a proof of concept for the load balancing properties of the proposed theory.

Information Fusion in Ad hoc Wireless Sensor Networks for Aircraft Health Monitoring

NASA Astrophysics Data System (ADS)

Fragoulis, Nikos; Tsagaris, Vassilis; Anastassopoulos, Vassilis

In this paper the use of an ad hoc wireless sensor network for implementing a structural health monitoring system is discussed. The network is consisted of sensors deployed throughout the aircraft. These sensors being in the form of a microelectronic chip and consisted of sensing, data processing and communicating components could be easily embedded in any mechanical aircraft component. The established sensor network, due to its ad hoc nature is easily scalable, allowing adding or removing any number of sensors. The position of the sensor nodes need not necessarily to be engineered or predetermined, giving this way the ability to be deployed in inaccessible points. Information collected from various sensors of different modalities throughout the aircraft is then fused in order to provide a more comprehensive image of the aircraft structural health. Sensor level fusion along with decision quality information is used, in order to enhance detection performance.

HOW GAS-DYNAMIC FLARE MODELS POWERED BY PETSCHEK RECONNECTION DIFFER FROM THOSE WITH AD HOC ENERGY SOURCES

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

Longcope, D. W.; Klimchuk, J. A.

Aspects of solar flare dynamics, such as chromospheric evaporation and flare light curves, have long been studied using one-dimensional models of plasma dynamics inside a static flare loop, subjected to some energy input. While extremely successful at explaining the observed characteristics of flares, all such models so far have specified energy input ad hoc, rather than deriving it self-consistently. There is broad consensus that flares are powered by magnetic energy released through reconnection. Recent work has generalized Petschek’s basic reconnection scenario, topological change followed by field line retraction and shock heating, to permit its inclusion in a one-dimensional flare loop model. Heremore » we compare the gas dynamics driven by retraction and shocking to those from more conventional static loop models energized by ad hoc source terms. We find significant differences during the first minute, when retraction leads to larger kinetic energies and produces higher densities at the loop top, while ad hoc heating tends to rarify the loop top. The loop-top density concentration is related to the slow magnetosonic shock, characteristic of Petschek’s model, but persists beyond the retraction phase occurring in the outflow jet. This offers an explanation for observed loop-top sources of X-ray and EUV emission, with advantages over that provided by ad hoc heating scenarios. The cooling phases of the two models are, however, notably similar to one another, suggesting that observations at that stage will yield little information on the nature of energy input.« less

Decentralized session initiation protocol solution in ad hoc networks

NASA Astrophysics Data System (ADS)

Han, Lu; Jin, Zhigang; Shu, Yantai; Dong, Linfang

2006-10-01

With the fast development of ad hoc networks, SIP has attracted more and more attention in multimedia service. This paper proposes a new architecture to provide SIP service for ad hoc users, although there is no centralized SIP server deployed. In this solution, we provide the SIP service by the introduction of two nodes: Designated SIP Server (DS) and its Backup Server (BDS). The nodes of ad hoc network designate DS and BDS when they join the session nodes set and when some pre-defined events occur. A new sip message type called REGISTRAR is presented so nodes can send others REGISTRAR message to declare they want to be DS. According to the IP information taken in the message, an algorithm works like the election of DR and BDR in OSPF protocol is used to vote DS and BDS SIP servers. Naturally, the DS will be replaced by BDS when the DS is down for predicable or unpredictable reasons. To facilitate this, the DS should register to the BDS and transfer a backup of the SIP users' database. Considering the possibility DS or BDS may abruptly go down, a special policy is given. When there is no DS and BDS, a new election procedure is triggered just like the startup phase. The paper also describes how SIP works normally in the decentralized model as well as the evaluation of its performance. All sessions based on SIP in ad hoc such as DS voting have been tested in the real experiments within a 500m*500m square area where about 30 random nodes are placed.

Efficient Byzantine Fault Tolerance for Scalable Storage and Services

DTIC Science & Technology

2009-07-01

most critical applications must survive in ever harsher environments. Less synchronous networking delivers packets unreliably and unpredictably, and... synchronous environments to allowing asynchrony, and from tolerating crashes to tolerating some corruptions through ad-hoc consistency checks. Ad-hoc...servers are responsive. To support this thesis statement, this disseration takes the following steps. First, it develops a new cryptographic primitive

Preserving Nevada's Environmental Heritage: A Report of the Ad Hoc Committee on Environmental Quality. Final Report to the Governor's Natural Resources Council.

ERIC Educational Resources Information Center

Nevada State Dept. of Conservation and Natural Resources, Carson City.

The Environmental Quality Ad Hoc Committee has prepared this report for the Governor's Natural Resources Council (Nevada). It is a compilation of available factual data focusing attention on needed statutory and administrative changes to preserve Nevada's environmental heritage and from which recommendations for future budgetary and legislative…

Report of the Ad Hoc Committee on Religious and Cultural Celebrations in the Library.

ERIC Educational Resources Information Center

Rathemacher, Andree; Grubman, Sheila Black; Lahiri, Amar; Gilton, Donna; Sharif, Mohammed

The charge of the University of Rhode Island's Ad Hoc Committee on Religious and Cultural Celebrations in the Library was to: investigate all opportunities for the library to educate the campus community about religious and cultural holidays; consider all the major religions of the world and the possibility of having displays for the symbols of…

Federal Government Printing and Publishing: Policy Issues. Report of the Ad Hoc Advisory Committee on Revision of Title 44.

ERIC Educational Resources Information Center

Joint Committee on Printing, Washington, DC.

Designed to present a better understanding of the government's system of printing and distributing information and to highlight problems, alternatives, and important policy questions, this report synthesizes 13 weeks of the Ad Hoc Advisory Committee hearings on six topics: (1) Administration of policy--who should establish and administer policy in…

The 5th Meeting of the Ad Hoc Panel on Terminal Configured Vehicles

NASA Technical Reports Server (NTRS)

1977-01-01

A report of the fifth meeting of the NASA Research and Technology Advisory Council, Ad Hoc panel on Terminal Configured Vehicles is presented. Some of the following topics were discussed; (1) microwave landing systems; (2) whole word computer system status; (3) flight path angle control: (4) VTOL approaches and landing technology; and (5) simulation study in wind shear.

Clinician Ratings of Interpreter Mediated Visits in Underserved Primary Care Settings with Ad hoc, In-person Professional, and Video Conferencing Modes

PubMed Central

Nápoles, Anna M.; Santoyo-Olsson, Jasmine; Karliner, Leah S.; O’Brien, Helen; Gregorich, Steven E.; Pérez-Stable, Eliseo J.

2013-01-01

Language interpretation ameliorates health disparities among underserved limited English-proficient patients, yet few studies have compared clinician satisfaction with these services. Self-administered clinician post-visit surveys compared the quality of interpretation and communication, visit satisfaction, degree of patient engagement, and cultural competence of visits using untrained people acting as interpreters (ad hoc), in-person professional, or video conferencing professional interpretation for 283 visits. Adjusting for clinician and patient characteristics, the quality of interpretation of in-person and video conferencing modes were rated similarly (OR=1.79; 95% CI 0.74, 4.33). The quality of in-person (OR=5.55; 95% CI 1.50, 20.51) and video conferencing (OR=3.10; 95% CI 1.16, 8.31) were rated higher than ad hoc interpretation. Self-assessed cultural competence was better for in-person versus video conferencing interpretation (OR=2.32; 95% CI 1.11, 4.86). Video conferencing interpretation increases access without compromising quality, but cultural nuances may be better addressed by in-person interpreters. Professional interpretation is superior to ad hoc (OR=4.15; 95% CI 1.43, 12.09). PMID:20173271

Scalability enhancement of AODV using local link repairing

NASA Astrophysics Data System (ADS)

Jain, Jyoti; Gupta, Roopam; Bandhopadhyay, T. K.

2014-09-01

Dynamic change in the topology of an ad hoc network makes it difficult to design an efficient routing protocol. Scalability of an ad hoc network is also one of the important criteria of research in this field. Most of the research works in ad hoc network focus on routing and medium access protocols and produce simulation results for limited-size networks. Ad hoc on-demand distance vector (AODV) is one of the best reactive routing protocols. In this article, modified routing protocols based on local link repairing of AODV are proposed. Method of finding alternate routes for next-to-next node is proposed in case of link failure. These protocols are beacon-less, means periodic hello message is removed from the basic AODV to improve scalability. Few control packet formats have been changed to accommodate suggested modification. Proposed protocols are simulated to investigate scalability performance and compared with basic AODV protocol. This also proves that local link repairing of proposed protocol improves scalability of the network. From simulation results, it is clear that scalability performance of routing protocol is improved because of link repairing method. We have tested protocols for different terrain area with approximate constant node densities and different traffic load.

Proficiency Standards and Cut-Scores for Language Proficiency Tests.

ERIC Educational Resources Information Center

Moy, Raymond H.

The problem of standard setting on language proficiency tests is often approached by the use of norms derived from the group being tested, a process commonly known as "grading on the curve." One particular problem with this ad hoc method of standard setting is that it will usually result in a fluctuating standard dependent on the particular group…

In Final Months, Education Department Seeks Teachers' Advice

ERIC Educational Resources Information Center

Hoff, David J.; Keller, Bess

2008-01-01

This article reports that by next fall--only months before she leaves office--U.S. Secretary of Education Margaret Spellings plans to have five teachers on her staff and set up a group of 20 ad hoc advisers still working in classrooms. Under the Teaching Ambassador Fellowship program the teachers would work at the department for one year starting…

A framework for addressing bird conservation priorities in high-elevation vegetation communities of the Appalachian Mountains

Treesearch

Brian W. Smith; Dean Demarest; Ed. Laurent

2010-01-01

The Appalachian Mountains Joint Venture (AMJV) is a self-directed, nonregulatory bird conservation partnership with the mission of restoring and sustaining native bird populations and their habitats throughout Appalachia. In 2008, the AMJV formed an ad hoc "high-elevation" technical working group to identify and address conservation priorities of bird species...

Two Phase Admission Control for QoS Mobile Ad Hoc Networks

NASA Astrophysics Data System (ADS)

Chen, Chien-Sheng; Su, Yi-Wen; Liu, Wen-Hsiung; Chi, Ching-Lung

In this paper a novel and effective two phase admission control (TPAC) for QoS mobile ad hoc networks is proposed that satisfies the real-time traffic requirements in mobile ad hoc networks. With a limited amount of extra overhead, TPAC can avoid network congestions by a simple and precise admission control which blocks most of the overloading flow-requests in the route discovery process. When compared with previous QoS routing schemes such as QoS-aware routing protocol and CACP protocols, it is shown from system simulations that the proposed scheme can increase the system throughput and reduce both the dropping rate and the end-to-end delay. Therefore, TPAC is surely an effective QoS-guarantee protocol to provide for real-time traffic.

Passive and Active Analysis in DSR-Based Ad Hoc Networks

NASA Astrophysics Data System (ADS)

Dempsey, Tae; Sahin, Gokhan; Morton, Y. T. (Jade)

Security and vulnerabilities in wireless ad hoc networks have been considered at different layers, and many attack strategies have been proposed, including denial of service (DoS) through the intelligent jamming of the most critical packet types of flows in a network. This paper investigates the effectiveness of intelligent jamming in wireless ad hoc networks using the Dynamic Source Routing (DSR) and TCP protocols and introduces an intelligent classifier to facilitate the jamming of such networks. Assuming encrypted packet headers and contents, our classifier is based solely on the observable characteristics of size, inter-arrival timing, and direction and classifies packets with up to 99.4% accuracy in our experiments. Furthermore, we investigate active analysis, which is the combination of a classifier and intelligent jammer to invoke specific responses from a victim network.

Information Sharing Modalities for Mobile Ad-Hoc Networks

NASA Astrophysics Data System (ADS)

de Spindler, Alexandre; Grossniklaus, Michael; Lins, Christoph; Norrie, Moira C.

Current mobile phone technologies have fostered the emergence of a new generation of mobile applications. Such applications allow users to interact and share information opportunistically when their mobile devices are in physical proximity or close to fixed installations. It has been shown how mobile applications such as collaborative filtering and location-based services can take advantage of ad-hoc connectivity to use physical proximity as a filter mechanism inherent to the application logic. We discuss the different modes of information sharing that arise in such settings based on the models of persistence and synchronisation. We present a platform that supports the development of applications that can exploit these modes of ad-hoc information sharing and, by means of an example, show how such an application can be realised based on the supported event model.

Ad-Hoc Networks and the Mobile Application Security System (MASS)

DTIC Science & Technology

2006-01-01

solution to this problem that addresses critical aspects of security in ad-hoc mobile application networks. This approach involves preventing unauthorized...modification of a mobile application , both by other applications and by hosts, and ensuring that mobile code is authentic and authorized. These...capabilities constitute the Mobile Application Security System (MASS). The MASS applies effective, robust security to mobile application -based systems

ARO PECASE: Information Assurance for Energy-Constrained Wireless Sensor Networks

DTIC Science & Technology

2011-12-21

Distribution, 18th Annual IEEE International Symposium on Personal, Indoor, and Mobile Radio Communications (PIMRC), September 2007. 2. 2010 IEEE...received the following awards: Student Best Paper Award at the IEEE International Symposium on Personal, Indoor, and Mobile Radio Communications (PIMRC...Localization in Wireless Ad Hoc Networks – Many current and future appli- cations of mobile ad hoc networks, including disaster response and event

AD HOC Networks for the Autonomous Car

NASA Astrophysics Data System (ADS)

Ron, Davidescu; Negrus, Eugen

2017-10-01

The future of the vehicle is made of cars, roads and infrastructures connected in a two way automated communication in a holistic system. It is a mandatory to use Encryption to maintain Confidentiality, Integrity and Availability in an ad hoc vehicle network. Vehicle to Vehicle communication, requires multichannel interaction between mobile, moving and changing parties to insure the full benefit from data sharing and real time decision making, a network of such users referred as mobile ad hoc network (MANET), however as ad hoc networks were not implemented in such a scale, it is not clear what is the best method and protocol to apply. Furthermore the visibility of secure preferred asymmetric encrypted ad hoc networks in a real time environment of dense moving autonomous vehicles has to be demonstrated, In order to evaluate the performance of Ad Hoc networks in changing conditions a simulation of multiple protocols was performed on large number of mobile nodes. The following common routing protocols were tested, DSDV is a proactive protocol, every mobile station maintains a routing table with all available destinations, DSR is a reactive routing protocol which allows nodes in the MANET to dynamically discover a source route across multiple network hops, AODV is a reactive routing protocol Instead of being proactive. It minimizes the number of broadcasts by creating routes based on demand, SAODV is a secure version of AODV, requires heavyweight asymmetric cryptographic, ARIANDE is a routing protocol that relies on highly efficient symmetric cryptography the concept is primarily based on DSR. A methodical evolution was performed in a various density of transportation, based on known communication bench mark parameters including, Throughput Vs. time, Routing Load per packets and bytes. Out of the none encrypted protocols, It is clear that in terms of performance of throughput and routing load DSR protocol has a clear advantage the high node number mode. The encrypted protocols show lower performance with ARIANDE being superior to SAODV and SRP. Nevertheless all protocol simulation proved it to match required real time performance.

Cross-Layer Service Discovery Mechanism for OLSRv2 Mobile Ad Hoc Networks.

PubMed

Vara, M Isabel; Campo, Celeste

2015-07-20

Service discovery plays an important role in mobile ad hoc networks (MANETs). The lack of central infrastructure, limited resources and high mobility make service discovery a challenging issue for this kind of network. This article proposes a new service discovery mechanism for discovering and advertising services integrated into the Optimized Link State Routing Protocol Version 2 (OLSRv2). In previous studies, we demonstrated the validity of a similar service discovery mechanism integrated into the previous version of OLSR (OLSRv1). In order to advertise services, we have added a new type-length-value structure (TLV) to the OLSRv2 protocol, called service discovery message (SDM), according to the Generalized MANET Packet/Message Format defined in Request For Comments (RFC) 5444. Each node in the ad hoc network only advertises its own services. The advertisement frequency is a user-configurable parameter, so that it can be modified depending on the user requirements. Each node maintains two service tables, one to store information about its own services and another one to store information about the services it discovers in the network. We present simulation results, that compare our service discovery integrated into OLSRv2 with the one defined for OLSRv1 and with the integration of service discovery in Ad hoc On-demand Distance Vector (AODV) protocol, in terms of service discovery ratio, service latency and network overhead.

Cross-Layer Service Discovery Mechanism for OLSRv2 Mobile Ad Hoc Networks

PubMed Central

Vara, M. Isabel; Campo, Celeste

2015-01-01

Service discovery plays an important role in mobile ad hoc networks (MANETs). The lack of central infrastructure, limited resources and high mobility make service discovery a challenging issue for this kind of network. This article proposes a new service discovery mechanism for discovering and advertising services integrated into the Optimized Link State Routing Protocol Version 2 (OLSRv2). In previous studies, we demonstrated the validity of a similar service discovery mechanism integrated into the previous version of OLSR (OLSRv1). In order to advertise services, we have added a new type-length-value structure (TLV) to the OLSRv2 protocol, called service discovery message (SDM), according to the Generalized MANET Packet/Message Format defined in Request For Comments (RFC) 5444. Each node in the ad hoc network only advertises its own services. The advertisement frequency is a user-configurable parameter, so that it can be modified depending on the user requirements. Each node maintains two service tables, one to store information about its own services and another one to store information about the services it discovers in the network. We present simulation results, that compare our service discovery integrated into OLSRv2 with the one defined for OLSRv1 and with the integration of service discovery in Ad hoc On-demand Distance Vector (AODV) protocol, in terms of service discovery ratio, service latency and network overhead. PMID:26205272

The use of Spanish language skills by physicians and nurses: policy implications for teaching and testing.

PubMed

Diamond, Lisa C; Tuot, Delphine S; Karliner, Leah S

2012-01-01

Language barriers present a substantial communication challenge in the hospital setting. To describe how clinicians with various levels of Spanish language proficiency work with interpreters or their own Spanish skills in common clinical scenarios. Survey of physicians and nurses who report ever speaking Spanish with patients on a general medicine hospital floor. Spanish proficiency rated on a 5-point scale, self-reported use of specific strategies (own Spanish skills, professional or ad-hoc interpreters) to overcome the language barrier. Sixty-eight physicians and 65 nurses participated. Physicians with low-level Spanish proficiency reported frequent use of ad-hoc interpreters for all information-based scenarios, except pre-rounding in the morning when most reported using their own Spanish skills. For difficult conversations and procedural consent, most used professional interpreters. Comparatively, physicians with medium proficiency reported higher rates of using their own Spanish skills for information-based scenarios, lower rates of professional interpreter use, and little use of ad-hoc interpreters. They rarely used their own Spanish skills or ad-hoc interpreters for difficult conversations. Physicians with high-level Spanish proficiency almost uniformly reported using their own Spanish skills. The majority (82%) of nurses had low-level Spanish proficiency, and frequently worked with professional interpreters for educating patients, but more often used ad hoc interpreters and their own Spanish skills for information-based scenarios, including medication administration. Physicians and nurses with limited Spanish proficiency use these skills, even in important clinical circumstances in the hospital. Health-care organizations should evaluate clinicians' non-English language proficiency and set policies about use of language skills in clinical care.

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 novel Smart Routing Protocol for remote health monitoring in Medical Wireless Networks.

PubMed

Sundararajan, T V P; Sumithra, M G; Maheswar, R

2014-01-01

In a Medical Wireless Network (MWN), sensors constantly monitor patient's physiological condition and movement. Inter-MWN communications are set up between the Patient Server and one or more Centralized Coordinators. However, MWNs require protocols with little energy consumption and the self-organizing attribute perceived in ad-hoc networks. The proposed Smart Routing Protocol (SRP) selects only the nodes with a higher residual energy and lower traffic density for routing. This approach enhances cooperation among the nodes of a Mobile Ad Hoc Network. Consequently, SRP produces better results than the existing protocols, namely Conditional Min-Max Battery Cost Routing, Min-Max Battery Cost Routing and AdHoc On-demand Distance Vector in terms of network parameters. The performance of the erstwhile schemes for routing protocols is evaluated using the network simulator Qualnet v 4.5.

Army Science Board Ad Hoc Study Group Report on Human Issues.

DTIC Science & Technology

1980-03-01

top level attention on human issues research and to formulate human issues programs to meet future needs. A concept paper was presented to the Army...the Army (Operations Research), 10 spaces were allo- cated to provide in-house research/study capability under the ADCSPER. These 10 spaces should be...combined with the present three- space study and analysis section, thus providing a 13- space group which could support the PPRC, APSC, and DCSPER. In

Health Behavior Changes After Genetic Risk Assessment for Alzheimer Disease: The REVEAL Study

PubMed Central

Chao, Serena; Roberts, J. Scott; Marteau, Theresa M.; Silliman, Rebecca; Cupples, L. Adrienne; Green, Robert C.

2008-01-01

Risk information for Alzheimer disease (AD) may be communicated through susceptibility gene disclosure, even though this is not currently in clinical use. The REVEAL Study is the first randomized clinical trial of risk assessment for AD with apolipoprotein E (APOE) genotype and numerical risk estimate disclosure. We examined whether APOE genotype and numerical risk disclosure to asymptomatic individuals at high risk for AD alters health behaviors. One hundred sixty-two participants were randomized to either intervention (APOE disclosure) or control (no genotype disclosure) groups. Subjects in both groups received numerical lifetime risk estimates of future AD development based on sex and family history of AD. The intervention group received their APOE genotype. Subjects were informed that no proven preventive measures for AD existed and given an information sheet on preventative therapies under investigation. Participants who learned they were ε4 positive were significantly more likely than ε4 negative participants to report AD-specific health behavior change 1 year after disclosure (adjusted odds ratio: 2.73; 95% confidence interval: 1.14, 6.54; P = 0.02). Post hoc analyses revealed similar significant associations between numerical lifetime risk estimates and self-report of AD-specific health behavior change. Despite lack of preventive measures for AD, knowledge of APOE genotype, numerical lifetime risk, or both, influences health behavior. PMID:18317253

Health behavior changes after genetic risk assessment for Alzheimer disease: The REVEAL Study.

PubMed

Chao, Serena; Roberts, J Scott; Marteau, Theresa M; Silliman, Rebecca; Cupples, L Adrienne; Green, Robert C

2008-01-01

Risk information for Alzheimer disease (AD) may be communicated through susceptibility gene disclosure, even though this is not currently in clinical use. The REVEAL Study is the first randomized clinical trial of risk assessment for AD with apolipoprotein E (APOE) genotype and numerical risk estimate disclosure. We examined whether APOE genotype and numerical risk disclosure to asymptomatic individuals at high risk for AD alters health behaviors. One hundred sixty-two participants were randomized to either intervention (APOE disclosure) or control (no genotype disclosure) groups. Subjects in both groups received numerical lifetime risk estimates of future AD development based on sex and family history of AD. The intervention group received their APOE genotype. Subjects were informed that no proven preventive measures for AD existed and given an information sheet on preventative therapies under investigation. Participants who learned they were epsilon 4 positive were significantly more likely than epsilon 4 negative participants to report AD-specific health behavior change 1 year after disclosure (adjusted odds ratio: 2.73; 95% confidence interval: 1.14, 6.54; P=0.02). Post hoc analyses revealed similar significant associations between numerical lifetime risk estimates and self-report of AD-specific health behavior change. Despite lack of preventive measures for AD, knowledge of APOE genotype, numerical lifetime risk, or both, influences health behavior.

Application of an automatic approach to calibrate the NEMURO nutrient-phytoplankton-zooplankton food web model in the Oyashio region

NASA Astrophysics Data System (ADS)

Ito, Shin-ichi; Yoshie, Naoki; Okunishi, Takeshi; Ono, Tsuneo; Okazaki, Yuji; Kuwata, Akira; Hashioka, Taketo; Rose, Kenneth A.; Megrey, Bernard A.; Kishi, Michio J.; Nakamachi, Miwa; Shimizu, Yugo; Kakehi, Shigeho; Saito, Hiroaki; Takahashi, Kazutaka; Tadokoro, Kazuaki; Kusaka, Akira; Kasai, Hiromi

2010-10-01

The Oyashio region in the western North Pacific supports high biological productivity and has been well monitored. We applied the NEMURO (North Pacific Ecosystem Model for Understanding Regional Oceanography) model to simulate the nutrients, phytoplankton, and zooplankton dynamics. Determination of parameters values is very important, yet ad hoc calibration methods are often used. We used the automatic calibration software PEST (model-independent Parameter ESTimation), which has been used previously with NEMURO but in a system without ontogenetic vertical migration of the large zooplankton functional group. Determining the performance of PEST with vertical migration, and obtaining a set of realistic parameter values for the Oyashio, will likely be useful in future applications of NEMURO. Five identical twin simulation experiments were performed with the one-box version of NEMURO. The experiments differed in whether monthly snapshot or averaged state variables were used, in whether state variables were model functional groups or were aggregated (total phytoplankton, small plus large zooplankton), and in whether vertical migration of large zooplankton was included or not. We then applied NEMURO to monthly climatological field data covering 1 year for the Oyashio, and compared model fits and parameter values between PEST-determined estimates and values used in previous applications to the Oyashio region that relied on ad hoc calibration. We substituted the PEST and ad hoc calibrated parameter values into a 3-D version of NEMURO for the western North Pacific, and compared the two sets of spatial maps of chlorophyll- a with satellite-derived data. The identical twin experiments demonstrated that PEST could recover the known model parameter values when vertical migration was included, and that over-fitting can occur as a result of slight differences in the values of the state variables. PEST recovered known parameter values when using monthly snapshots of aggregated state variables, but estimated a different set of parameters with monthly averaged values. Both sets of parameters resulted in good fits of the model to the simulated data. Disaggregating the variables provided to PEST into functional groups did not solve the over-fitting problem, and including vertical migration seemed to amplify the problem. When we used the climatological field data, simulated values with PEST-estimated parameters were closer to these field data than with the previously determined ad hoc set of parameter values. When these same PEST and ad hoc sets of parameter values were substituted into 3-D-NEMURO (without vertical migration), the PEST-estimated parameter values generated spatial maps that were similar to the satellite data for the Kuroshio Extension during January and March and for the subarctic ocean from May to November. With non-linear problems, such as vertical migration, PEST should be used with caution because parameter estimates can be sensitive to how the data are prepared and to the values used for the searching parameters of PEST. We recommend the usage of PEST, or other parameter optimization methods, to generate first-order parameter estimates for simulating specific systems and for insertion into 2-D and 3-D models. The parameter estimates that are generated are useful, and the inconsistencies between simulated values and the available field data provide valuable information on model behavior and the dynamics of the ecosystem.

A Survey on Trust Management for Mobile Ad Hoc Networks

DTIC Science & Technology

2011-11-01

expects, trust is dangerous implying the possible betrayal of trust. In his comments on Lagerspetz’s book titled Trust: The Tacit Demand, Lahno [24...AODV Zouridaki et al. (2005 ) [79] (2006) [80] Secure routing Direct observation [79][80] Reputation by secondhand information [80] Packet dropping...areas of signal processing, wireless communications, sensor and mobile ad hoc networks. He is co-editor of the book Wireless Sensor Networks: Signal

Achieving Information Superiority Using Hastily Formed Networks and Emerging Technologies for the Royal Thai Armed Forces Counterinsurgency Operations in Southern Thailand

DTIC Science & Technology

2014-03-01

38 2. Mobile Ad Hoc Networks ..................................................................39 3. Wireless Ad Hoc Sensor Networks...59 Figure 32. RENEWS with WiMAX and Wave Relay AP at C-IED Site.............................59 Figure 33. RENEWS Wind Turbine and Solar Panels at Hat...worldwide interoperability for microwave access WSN wireless sensor network xv ACKNOWLEDGMENTS We would like to express our sincerest gratitude

Space-Time Processing for Tactical Mobile Ad Hoc Networks

DTIC Science & Technology

2007-08-01

rates in mobile ad hoc networks. In addition, he has considered the design of a cross-layer multi-user resource allocation framework using a... framework for many-to-one communication. In this context, multiple nodes cooperate to transmit their packets simultaneously to a single node using multi...spatially multiplexed signals transmitted from multiple nodes. Our goal is to form a framework that activates different sets of communication links

Space-Time Processing for Tactical Mobile Ad Hoc Networks

DTIC Science & Technology

2008-08-01

vision for multiple concurrent communication settings, i.e., a many-to-many framework where multi-packet transmissions (MPTs) and multi-packet...modelling framework of capacity-delay tradeoffs We have introduced the first unified modeling framework for the computation of fundamental limits o We...dalities in wireless n twor i-packet modelling framework to account for the use of m lti-packet reception (MPR) f ad hoc networks with MPT under

An Experimental Investigation of Computer Program Development Approaches and Computer Programming Metrics.

DTIC Science & Technology

1979-12-01

team progranming in reducing software dleveloup- ment costs relative to ad hoc approaches and improving software product quality relative to...are interpreted as demonstrating the advantages of disciplined team programming in reducing software development costs relative to ad hoc approaches...is due oartialty to the cost and imoracticality of a valiI experimental setup within a oroauct ion environment. Thus the question remains, are

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.

Modern Foreign Language Teachers--Don't Leave Those Kids Alone! Linguistic-Cultural "Give and Take" in an Ad-Hoc Tutoring Scheme

ERIC Educational Resources Information Center

Leroy, Norah

2017-01-01

This paper addresses the theme of social inclusion through language learning. The focus is on an ad-hoc tutoring scheme set up between newly arrived British migrant pupils and French monolingual pupils in a small secondary school in the south-west of France. Though the original objective of this tutoring scheme was to improve the English skills of…

Overview of the TREC-2014 Microblog Track

DTIC Science & Technology

2014-11-01

tweets as part of writing a retrospective piece about the impact of social media on the Egyptian revolution. The topic is temporally-anchored in the...imagined that participants would tackle the TTG task in a pipelined architecture that begins with ad hoc retrieval followed by summary generation...random selection of 100 tweets per topic from each TTG run. Although we envisioned a sys- tem architecture consisting of ad hoc retrieval followed by

An artificial immune system approach with secondary response for misbehavior detection in mobile ad hoc networks.

PubMed

Sarafijanović, Slavisa; Le Boudec, Jean-Yves

2005-09-01

In mobile ad hoc networks, nodes act both as terminals and information relays, and they participate in a common routing protocol, such as dynamic source routing (DSR). The network is vulnerable to routing misbehavior, due to faulty or malicious nodes. Misbehavior detection systems aim at removing this vulnerability. In this paper, we investigate the use of an artificial immune system (AIS) to detect node misbehavior in a mobile ad hoc network using DSR. The system is inspired by the natural immune system (IS) of vertebrates. Our goal is to build a system that, like its natural counterpart, automatically learns, and detects new misbehavior. We describe our solution for the classification task of the AIS; it employs negative selection and clonal selection, the algorithms for learning and adaptation used by the natural IS. We define how we map the natural IS concepts such as self, antigen, and antibody to a mobile ad hoc network and give the resulting algorithm for classifying nodes as misbehaving. We implemented the system in the network simulator Glomosim; we present detection results and discuss how the system parameters affect the performance of primary and secondary response. Further steps will extend the design by using an analogy to the innate system, danger signal, and memory cells.

A game-theoretic approach to optimize ad hoc networks inspired by small-world network topology

NASA Astrophysics Data System (ADS)

Tan, Mian; Yang, Tinghong; Chen, Xing; Yang, Gang; Zhu, Guoqing; Holme, Petter; Zhao, Jing

2018-03-01

Nodes in ad hoc networks are connected in a self-organized manner. Limited communication radius makes information transmit in multi-hop mode, and each forwarding needs to consume the energy of nodes. Insufficient communication radius or exhaustion of energy may cause the absence of some relay nodes and links, further breaking network connectivity. On the other hand, nodes in the network may refuse to cooperate due to objective faulty or personal selfish, hindering regular communication in the network. This paper proposes a model called Repeated Game in Small World Networks (RGSWN). In this model, we first construct ad hoc networks with small-world feature by forming "communication shortcuts" between multiple-radio nodes. Small characteristic path length reduces average forwarding times in networks; meanwhile high clustering coefficient enhances network robustness. Such networks still maintain relative low global power consumption, which is beneficial to extend the network survival time. Then we use MTTFT strategy (Mend-Tolerance Tit-for-Tat) for repeated game as a rule for the interactions between neighbors in the small-world networks. Compared with other five strategies of repeated game, this strategy not only punishes the nodes' selfishness more reasonably, but also has the best tolerance to the network failure. This work is insightful for designing an efficient and robust ad hoc network.

Sembragiline in Moderate Alzheimer’s Disease: Results of a Randomized, Double-Blind, Placebo-Controlled Phase II Trial (MAyflOwer RoAD)

PubMed Central

Nave, Stephane; Doody, Rachelle S.; Boada, Mercè; Grimmer, Timo; Savola, Juha-Matti; Delmar, Paul; Pauly-Evers, Meike; Nikolcheva, Tania; Czech, Christian; Borroni, Edilio; Ricci, Benedicte; Dukart, Juergen; Mannino, Marie; Carey, Tracie; Moran, Emma; Gilaberte, Inma; Muelhardt, Nicoletta Milani; Gerlach, Irene; Santarelli, Luca; Ostrowitzki, Susanne; Fontoura, Paulo

2017-01-01

Background: Sembragiline is a potent, selective, long-acting, and reversible MAO-B inhibitor developed as a potential treatment for Alzheimer’s disease (AD). Objective: To evaluate the safety, tolerability, and efficacy of sembragiline in patients with moderate AD. Methods: In this Phase II study (NCT01677754), 542 patients with moderate dementia (MMSE 13–20) on background acetylcholinesterase inhibitors with/without memantine were randomized (1:1:1) to sembragiline 1 mg, 5 mg, or placebo once daily orally for 52 weeks. Results: No differences between treated groups and placebo in adverse events or in study completion. The primary endpoint, change from baseline in ADAS-Cog11, was not met. At Week 52, the difference between sembragiline and placebo in ADAS-Cog11 change from baseline was – 0.15 (p = 0.865) and 0.90 (p = 0.312) for 1 and 5 mg groups, respectively. Relative to placebo at Week 52 (but not at prior assessment times), the 1 mg and 5 mg sembragiline groups showed differences in ADCS-ADL of 2.64 (p = 0.051) and 1.89 (p = 0.160), respectively. A treatment effect in neuropsychiatric symptoms (as assessed by the difference between sembragiline and placebo on BEHAVE-AD-FW) was also seen at Week 52 only: – 2.80 (p = 0.014; 1 mg) and – 2.64 (p = 0.019; 5 mg), respectively. A post hoc subgroup analysis revealed greater treatment effects on behavior and functioning in patients with more severe baseline behavioral symptoms (above the median). Conclusions: This study showed that sembragiline was well-tolerated in patients with moderate AD. The study missed its primary and secondary endpoints. Post hoc analyses suggested potential effect on neuropsychiatric symptoms and functioning in more behaviorally impaired study population at baseline. PMID:28550255

Commission 5: Documentation and Astronomical Data

NASA Astrophysics Data System (ADS)

Ohishi, Masatoshi; Hanisch, Robert J.; Norris, Ray P.; Andernach, Heinz; Bishop, Marsha; Griffin, Elizabeth; Kembhavi, Ajit; Murphy, Tara; Pasian, Fabio

2012-04-01

IAU Commission 5 (http://www.nao.ac.jp/IAU/Com5/) deals with data management issues, and its working groups and task group deal specifically with information handling, with data centers and networks, with technical aspects of collection, archiving, storage and dissemination of data, with designations and classification of astronomical objects, with library services, editorial policies, computer communications, ad hoc methodologies, and with various standards, reference frames, etc. FITS (Flexible Image Transport System), the major data exchange format in astronomy, has been standardized, maintained and updated by the FITS working group under Commission 5.

A Survey on Trust Management for Mobile Ad Hoc Networks

DTIC Science & Technology

2010-07-01

betrayal of trust. In his comments on Lagerspetz’s book titled Trust: The Tacit Demand, Lahno [24] describes the author’s view on trust as a moral...extension of AODV Zouridaki et al. (2005 ) [79] (2006) [80] Secure routing Direct observation [79][80] Reputation by secondhand information [80...the broad areas of signal processing, wireless communications, sensor and mobile ad hoc networks. He is co-editor of the book Wireless Sensor Networks

Dynamic Data Driven Applications Systems (DDDAS)

DTIC Science & Technology

2013-03-06

INS •  Chip-scale atomic clocks •  Ad hoc networks •  Polymorphic networks •  Agile networks •  Laser communications •  Frequency-agile RF...atomi clocks •  Ad hoc networks •  Polymorphic networks •  Agile networks •  Laser co munications •  Frequency-agile RF systems...Real-Time Doppler Wind Wind field Sensor observations Energy Estimation Atmospheric Models for On-line Planning Planning and Control

Analysis of Soldier Radio Waveform Performance in Operational Test

DTIC Science & Technology

2015-05-01

different frequencies based on carrier, uplink/downlink, and generation. In general, 2G and 3G cellular phones operate at 850 MHz uplink, and 1,900 MHz...spectrum management that may not be operationally feasible. These issues are not unique to SRW, but rather have plagued the mobile ad-hoc network... mobile ad-hoc network (MANET), enabling communication through a self-configuring, infrastructure-less network of mobile nodes. In the SS domain, these

ARSENAL: A Cross Layer Architecture for Secure Resilient Tactical Mobile AdHoc Networks

DTIC Science & Technology

2016-01-21

stations separated by 0.5 to 1 km can be coherently measured to a single mobile subscriber using LTE signaling. These are the first measurements of...undertake three parallel but inter-coupled tasks geared towards a) performing measurements via real deployments and enhancing our understanding of layer...dependencies and vulnerabilities in mobile ad hoc networks; these measurements will be on existing testbeds at The views, opinions and/or findings

ARSENAL: A Cross Layer Architecture for SecureResilient Tactical Mobile AdHoc Networks

DTIC Science & Technology

2016-01-21

stations separated by 0.5 to 1 km can be coherently measured to a single mobile subscriber using LTE signaling. These are the first measurements of...undertake three parallel but inter-coupled tasks geared towards a) performing measurements via real deployments and enhancing our understanding of layer...dependencies and vulnerabilities in mobile ad hoc networks; these measurements will be on existing testbeds at The views, opinions and/or findings

Analytical Models of Cross-Layer Protocol Optimization in Real-Time Wireless Sensor Ad Hoc Networks

NASA Astrophysics Data System (ADS)

Hortos, William S.

The real-time interactions among the nodes of a wireless sensor network (WSN) to cooperatively process data from multiple sensors are modeled. Quality-of-service (QoS) metrics are associated with the quality of fused information: throughput, delay, packet error rate, etc. Multivariate point process (MVPP) models of discrete random events in WSNs establish stochastic characteristics of optimal cross-layer protocols. Discrete-event, cross-layer interactions in mobile ad hoc network (MANET) protocols have been modeled using a set of concatenated design parameters and associated resource levels by the MVPPs. Characterization of the "best" cross-layer designs for a MANET is formulated by applying the general theory of martingale representations to controlled MVPPs. Performance is described in terms of concatenated protocol parameters and controlled through conditional rates of the MVPPs. Modeling limitations to determination of closed-form solutions versus explicit iterative solutions for ad hoc WSN controls are examined.

Temporal patterns of scientific information-seeking on Google and Wikipedia.

PubMed

Segev, Elad; Sharon, Aviv J

2017-11-01

In response to the news coverage of scientific events and to science education, people increasingly go online to get more information. This study investigates how patterns of science and technology information-seeking on Google and Wikipedia change over time, in ways that differ between "ad hoc" terms that correspond to news coverage and "cyclic" terms that correspond to the academic period. Findings show that the science and technology activity in Google and Wikipedia was significantly associated with ad hoc and cyclic patterns. While the peak activity in Google and Wikipedia largely overlapped for ad hoc terms, it mismatched for cyclic terms. The findings indicate the importance of external cues such as news media and education, and also of the online engagement process, and particularly the crucial but different role played by Google and Wikipedia in gaining science and technology knowledge. Educators and policy makers could benefit from taking into account those different patterns.

Adaptive MANET multipath routing algorithm based on the simulated annealing approach.

PubMed

Kim, Sungwook

2014-01-01

Mobile ad hoc network represents a system of wireless mobile nodes that can freely and dynamically self-organize network topologies without any preexisting communication infrastructure. Due to characteristics like temporary topology and absence of centralized authority, routing is one of the major issues in ad hoc networks. In this paper, a new multipath routing scheme is proposed by employing simulated annealing approach. The proposed metaheuristic approach can achieve greater and reciprocal advantages in a hostile dynamic real world network situation. Therefore, the proposed routing scheme is a powerful method for finding an effective solution into the conflict mobile ad hoc network routing problem. Simulation results indicate that the proposed paradigm adapts best to the variation of dynamic network situations. The average remaining energy, network throughput, packet loss probability, and traffic load distribution are improved by about 10%, 10%, 5%, and 10%, respectively, more than the existing schemes.

Hybrid Radio Frequency/Free-Space Optics (RF/FSO) Wireless Sensor Network: Security Concerns and Protective Measures

NASA Astrophysics Data System (ADS)

Banerjee, Koushik; Sharma, Hemant; Sengupta, Anasuya

Wireless sensor networks (WSNs) are ad hoc wireless networks that are written off as spread out structure and ad hoc deployment. Sensor networks have all the rudimentary features of ad hoc networks but to altered points—for instance, considerably lesser movement and far more energy necessities. Commonly used technology for communication is radio frequency (RF) communications. Free-space optics (FSO) is relatively new technology which has the prospective to deliver remarkable increases in network lifetime of WSN. Hybrid RF/FSO communications has been suggested to decrease power consumption by a single sensor node. It is observed that security plays a very important role for either RF WSN or hybrid RF/FSO WSN as those are vulnerable to numerous threats. In this paper, various possible attacks in RF/FSO WSN are discussed and aimed to propose some way out from those attacks.

Design of free patterns of nanocrystals with ad hoc features via templated dewetting

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

Aouassa, M.; Berbezier, I.; Favre, L.

Design of monodisperse ultra-small nanocrystals (NCs) into large scale patterns with ad hoc features is demonstrated. The process makes use of solid state dewetting of a thin film templated through alloy liquid metal ion source focused ion beam (LMIS-FIB) nanopatterning. The solid state dewetting initiated at the edges of the patterns controllably creates the ordering of NCs with ad hoc placement and periodicity. The NC size is tuned by varying the nominal thickness of the film while their position results from the association of film retraction from the edges of the lay out and Rayleigh-like instability. The use of ultra-highmore » resolution LMIS-FIB enables to produce monocrystalline NCs with size, periodicity, and placement tunable as well. It provides routes for the free design of nanostructures for generic applications in nanoelectronics.« less

Forming an ad-hoc nearby storage, based on IKAROS and social networking services

NASA Astrophysics Data System (ADS)

Filippidis, Christos; Cotronis, Yiannis; Markou, Christos

2014-06-01

We present an ad-hoc "nearby" storage, based on IKAROS and social networking services, such as Facebook. By design, IKAROS is capable to increase or decrease the number of nodes of the I/O system instance on the fly, without bringing everything down or losing data. IKAROS is capable to decide the file partition distribution schema, by taking on account requests from the user or an application, as well as a domain or a Virtual Organization policy. In this way, it is possible to form multiple instances of smaller capacity higher bandwidth storage utilities capable to respond in an ad-hoc manner. This approach, focusing on flexibility, can scale both up and down and so can provide more cost effective infrastructures for both large scale and smaller size systems. A set of experiments is performed comparing IKAROS with PVFS2 by using multiple clients requests under HPC IOR benchmark and MPICH2.

Factors of Safety, Historical Development, State of the Art and Future Outlook

DTIC Science & Technology

1977-11-01

The 1.33 value was a common factor used for pressure vessel designs, which was a major design aspect ior many missiles. The apparent intent was to...DISTRIBUTION AND AVAIL ABWLII-Tf ON BACK COVER TL~ - 211T, AGARD-R-661 ORGANISATION DU TRAITE DE L’ATLANTIQUE NORD GROUP CONSULTATIF POURLA RECHERCHE ET LE...Structural and Materials Panel formed an ad hoc Group to condense this discussion. The three pilot papers contained in this report address thedifferent

In the National Interest: The Federal Government and Research-Intensive Universities. A Report from the Ad Hoc Working Group on Research-Intensive Universities and the Federal Government.

ERIC Educational Resources Information Center

Federal Coordinating Council for Science, Engineering and Technology, Washington, DC.

This report looks at the relationship between the federal government and research intensive universities (RIUs), identifies critical trends and issues that are affecting their relationship, and offers principles and recommendations for the future. Following an introduction, the origins and characteristics of the relations between the federal…

Three year outcomes of an early intervention for psychosis service as compared with treatment as usual for first psychotic episodes in a standard community mental health team. Preliminary results.

PubMed

Agius, Mark; Shah, Samir; Ramkisson, Roshelle; Murphy, Suzanne; Zaman, Rashid

2007-06-01

Forty patients who had been treated for three years in an ad-hoc, assertive treatment team for patients who had suffered a first psychotic episode were compared to forty patients who had been followed up after a first psychotic episode in a community mental health team. All patients had suffered a first or early psychotic episode. The main differences between the two teams was that the ad-hoc team was assertive in its approach, offered more structured psycho-education, relapse prevention and psycho-social interventions, and had a policy of using atypical anti-psychotics at the lowest effective dose. There were many differences in outcome measures at the end of three years between the two groups. The EI patients are more likely to be taking medication at the end of three years. They are more compliant with medication. They are more likely to be prescribed atypical medication. The EI patients are more likely to have returned to work or education. The EI patients are more likely to remain living with their families. They are less likely to suffer depression to the extent of requiring anti-depressants. They appear to commit less suicide attempts. The patients in the EI service also appear to be less likely to suffer relapse and re-hospitalisation, and are less likely to have involuntary admission to hospital. They have systematic relapse prevention plans based on early warning signs. They and their families receive more psycho-education. These indications suggest that the EI patients are at the end of three years better able to manage their illness/vulnerability on their own than the CMHT patients. More patients in the EI group stopped using illicit drugs than in the CMHT group. All the above changes were statistically significant except for the number of patients who stopped using illicit drugs. In this case it is believed that the sample size was too small to demonstrate significance. These results suggest that an ad-hoc early intervention team is more effective than standard community mental health team in treating psychotic illness.

Three year outcomes of an early intervention for psychosis service as compared with treatment as usual for first psychotic episodes in a standard community mental health team - final results.

PubMed

Agius, Mark; Shah, Samir; Ramkisson, Roshelle; Murphy, Suzanne; Zaman, Rashid

2007-09-01

Sixty-two patients who had been treated for three years in an ad-hoc, assertive treatment team for patients who had suffered a first psychotic episode were compared to sixty-two patients who had been followed up after a first psychotic episode in a community mental health team. All patients had suffered a first or early psychotic episode. The main differences between the two teams was that the ad-hoc team was assertive in its approach, offered more structured psycho-education, relapse prevention and psycho-social interventions, and had a policy of using atypical anti-psychotics at the lowest effective dose. There were many differences in outcome measures at the end of three years between the two groups. The EI patients are more likely to be taking medication at the end of three years. They are more compliant with medication. They are more likely to be prescribed Atypical Medication. The EI patients are more likely to have returned to Work or Education. The EI patients are more likely to remain living with their families. They are less likely to suffer depression to the extent of requiring anti-depressants. They appear to commit less suicide attempts. The patients in the EI service also appear to be less likely to suffer relapse and re-hospitalisation, and are less likely to have involuntary admission to hospital. They have systematic relapse prevention plans based on Early Warning Signs. They and their families receive more psycho-education. These indications suggest that the EI patients are at the end of three years better able to manage their illness/vulnerability on their own than the CMHT patients. More patients in the EI group stopped using illicit drugs than in the CMHT group. All the above changes were statistically significant except for the total improvement in employment status and education status, which however approached significance. These results suggest that an ad-hoc Early Intervention Team is more effective than standard Community Mental Health Team in treating psychotic illness.

Coverage in Heterogeneous Sensor Networks

DTIC Science & Technology

2006-01-01

and S. Banerjee, “Node Placement for Connected Coverage in Sensor Networks,” in Proceedings of WiOpt ’03, March 2003. [10] F. Koushanfar, S...Meguerdichian, M. Potkonjak, and M. Srivastava, Cov- erage Problems in Wireless Ad-Hoc Sensor Networks, in Proceedings of the IEEE INFOCOM 01, March 2001, pp...Coverage and Connectivity of Ad Hoc Networks in Presence of Channel Randomness,” in Proceedings of the IEEE INFOCOM 05, March 2005, pp. 491–502. [16] S

Secure Mobile Distributed File System (MDFS)

DTIC Science & Technology

2011-03-01

dissemination of data. In a mobile ad - hoc network, there are two classes of devices: content generators and content consumers. One im- plementation of...use of infrastructure mode is necessary because current Android implemen- tations do not support Mobile Ad - Hoc network without modification of the...NUMBER (include area code ) Standard Form 298 (Rev. 8–98) Prescribed by ANSI Std. Z39.18 24–3–2011 Master’s Thesis 2009-03-01—2011-03-31 Secure Mobile

Anomaly Detection for Data Reduction in an Unattended Ground Sensor (UGS) Field

DTIC Science & Technology

2014-09-01

information (shown with solid lines in the diagram). Typically, this would be a mobile ad - hoc network (MANET). The clusters are connected to other nodes...interquartile ranges MANET mobile ad - hoc network OSUS Open Standards for Unattended Sensors TOC tactical operations center UAVs unmanned aerial vehicles...19b. TELEPHONE NUMBER (Include area code ) 301-394-1221 Standard Form 298 (Rev. 8/98) Prescribed by ANSI Std. Z39.18 iii Contents List of

Adaptive Flow Control for Enabling Quality of Service in Tactical Ad Hoc Wireless Networks

DTIC Science & Technology

2010-12-01

environment in wireless networks , we use sensors in the network routers to detect and respond to congestion. We use backpressure techniques... wireless mesh network . In the current approach, we used OLSR as the routing scheme. However, B.A.T.M.A.N. offers the significant advantage of being based...Control and QoS Routing in Multi-Channel Wireless Mesh Networks ,” 68-77. ACM International Symposium on Mobile Ad Hoc Networking &

Ad hoc categories and false memories: Memory illusions for categories created on-the-spot.

PubMed

Soro, Jerônimo C; Ferreira, Mário B; Semin, Gün R; Mata, André; Carneiro, Paula

2017-11-01

Three experiments were designed to test whether experimentally created ad hoc associative networks evoke false memories. We used the DRM (Deese, Roediger, McDermott) paradigm with lists of ad hoc categories composed of exemplars aggregated toward specific goals (e.g., going for a picnic) that do not share any consistent set of features. Experiment 1 revealed considerable levels of false recognitions of critical words from ad hoc categories. False recognitions occurred even when the lists were presented without an organizing theme (i.e., the category's label). Experiments 1 and 2 tested whether (a) the ease of identifying the categories' themes, and (b) the lists' backward associative strength could be driving the effect. List identifiability did not correlate with false recognition, and the effect remained even when backward associative strength was controlled for. Experiment 3 manipulated the distractor items in the recognition task to address the hypothesis that the salience of unrelated items could be facilitating the occurrence of the phenomenon. The effect remained when controlling for this source of facilitation. These results have implications for assumptions made by theories of false memories, namely the preexistence of associations in the activation-monitoring framework and the central role of gist extraction in fuzzy-trace theory, while providing evidence of the occurrence of false memories for more dynamic and context-dependent knowledge structures. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Capacity-Delay Trade-Off in Collaborative Hybrid Ad-Hoc Networks with Coverage Sensing.

PubMed

Chen, Lingyu; Luo, Wenbin; Liu, Chen; Hong, Xuemin; Shi, Jianghong

2017-01-26

The integration of ad hoc device-to-device (D2D) communications and open-access small cells can result in a networking paradigm called hybrid the ad hoc network, which is particularly promising in delivering delay-tolerant data. The capacity-delay performance of hybrid ad hoc networks has been studied extensively under a popular framework called scaling law analysis. These studies, however, do not take into account aspects of interference accumulation and queueing delay and, therefore, may lead to over-optimistic results. Moreover, focusing on the average measures, existing works fail to give finer-grained insights into the distribution of delays. This paper proposes an alternative analytical framework based on queueing theoretic models and physical interference models. We apply this framework to study the capacity-delay performance of a collaborative cellular D2D network with coverage sensing and two-hop relay. The new framework allows us to fully characterize the delay distribution in the transform domain and pinpoint the impacts of coverage sensing, user and base station densities, transmit power, user mobility and packet size on the capacity-delay trade-off. We show that under the condition of queueing equilibrium, the maximum throughput capacity per device saturates to an upper bound of 0.7239 λ b / λ u bits/s/Hz, where λ b and λ u are the densities of base stations and mobile users, respectively.

Strategies for generating multiple instances of common and ad hoc categories.

PubMed

Vallée-Tourangeau, F; Anthony, S H; Austin, N G

1998-09-01

In a free-emission procedure participants were asked to generate instances of a given category and to report, retrospectively, the strategies that they were aware of using in retrieving instances. In two studies reported here, participants generated instances for common categories (e.g. fruit) and for ad hoc categories (e.g., things people keep in their pockets) for 90 seconds and for each category described how they had proceeded in doing so. Analysis of the protocols identified three broad classes of strategy: (1) experiential, where memories of specific or generic personal experiences involving interactions with the category instances acted as cues; (2) semantic, where a consideration of abstract conceptual characteristics of a category were employed to retrieve category exemplars; (3) unmediated, where instances were effortlessly retrieved without mediating cognitions of which subjects were aware. Experiential strategies outnumbered semantic strategies (on average 4 to 1) not only for ad hoc categories but also for common categories. This pattern was noticeably reversed for ad hoc categories that subjects were unlikely to have experienced personally (e.g. things sold on the black market in Russia). Whereas more traditional accounts of semantic memory have favoured decontextualised abstract representations of category knowledge, to the extent that mode of access informs us of knowledge structures, our data suggest that category knowledge is significantly grounded in terms of everyday contexts where category instances are encountered.

Capacity-Delay Trade-Off in Collaborative Hybrid Ad-Hoc Networks with Coverage Sensing

PubMed Central

Chen, Lingyu; Luo, Wenbin; Liu, Chen; Hong, Xuemin; Shi, Jianghong

2017-01-01

The integration of ad hoc device-to-device (D2D) communications and open-access small cells can result in a networking paradigm called hybrid the ad hoc network, which is particularly promising in delivering delay-tolerant data. The capacity-delay performance of hybrid ad hoc networks has been studied extensively under a popular framework called scaling law analysis. These studies, however, do not take into account aspects of interference accumulation and queueing delay and, therefore, may lead to over-optimistic results. Moreover, focusing on the average measures, existing works fail to give finer-grained insights into the distribution of delays. This paper proposes an alternative analytical framework based on queueing theoretic models and physical interference models. We apply this framework to study the capacity-delay performance of a collaborative cellular D2D network with coverage sensing and two-hop relay. The new framework allows us to fully characterize the delay distribution in the transform domain and pinpoint the impacts of coverage sensing, user and base station densities, transmit power, user mobility and packet size on the capacity-delay trade-off. We show that under the condition of queueing equilibrium, the maximum throughput capacity per device saturates to an upper bound of 0.7239 λb/λu bits/s/Hz, where λb and λu are the densities of base stations and mobile users, respectively. PMID:28134769

Transactive memory in organizational groups: the effects of content, consensus, specialization, and accuracy on group performance.

PubMed

Austin, John R

2003-10-01

Previous research on transactive memory has found a positive relationship between transactive memory system development and group performance in single project laboratory and ad hoc groups. Closely related research on shared mental models and expertise recognition supports these findings. In this study, the author examined the relationship between transactive memory systems and performance in mature, continuing groups. A group's transactive memory system, measured as a combination of knowledge stock, knowledge specialization, transactive memory consensus, and transactive memory accuracy, is positively related to group goal performance, external group evaluations, and internal group evaluations. The positive relationship with group performance was found to hold for both task and external relationship transactive memory systems.

The Time-Course of Sentence Meaning Composition. N400 Effects of the Interaction between Context-Induced and Lexically Stored Affordances

PubMed Central

Cosentino, Erica; Baggio, Giosuè; Kontinen, Jarmo; Werning, Markus

2017-01-01

Contemporary semantic theories can be classified along two dimensions: (i) the way and time-course in which contextual factors influence sentence truth-conditions; and (ii) whether and to what extent comprehension involves sensory, motor and emotional processes. In order to explore this theoretical space, our ERP study investigates the time-course of the interaction between the lexically specified telic component of a noun (the function of the object to which the noun refers to, e.g., a funnel is generally used to pour liquids into containers) and an ad-hoc affordance contextually induced by the situation described in the discourse. We found that, if preceded by a neutral discourse context, a verb incongruent with the noun's telic component as in “She uses the funnel to hang her coat” elicited an enhanced N400 compared to a congruent verb as in “She uses the funnel to pour water into a container.” However, if the situation introduced in the preceding discourse induced a new function for the object as an ad-hoc affordance (e.g., the funnel is glued to the wall and the agent wants to hang the coat), we observed a crossing-over regarding the direction of the N400 effect: comparing the ad-hoc affordance-inducing context with the neutral context, the N400 for the incongruent verb was significantly reduced, whereas the N400 for the congruent verb was significantly enhanced. We explain these results as a consequence of the incorporation of the contextually triggered ad-hoc affordance into the meaning of the noun. Combining these results with an analysis of semantic similarity values between test sentences and contexts, we argue that one possibility is that the incorporation of an ad-hoc affordance may be explained on the basis of the mental simulation of concurrent motor information. PMID:28603506

The Time-Course of Sentence Meaning Composition. N400 Effects of the Interaction between Context-Induced and Lexically Stored Affordances.

PubMed

Cosentino, Erica; Baggio, Giosuè; Kontinen, Jarmo; Werning, Markus

2017-01-01

Contemporary semantic theories can be classified along two dimensions: (i) the way and time-course in which contextual factors influence sentence truth-conditions; and (ii) whether and to what extent comprehension involves sensory, motor and emotional processes. In order to explore this theoretical space, our ERP study investigates the time-course of the interaction between the lexically specified telic component of a noun (the function of the object to which the noun refers to, e.g., a funnel is generally used to pour liquids into containers) and an ad-hoc affordance contextually induced by the situation described in the discourse. We found that, if preceded by a neutral discourse context, a verb incongruent with the noun's telic component as in "She uses the funnel to hang her coat" elicited an enhanced N400 compared to a congruent verb as in "She uses the funnel to pour water into a container." However, if the situation introduced in the preceding discourse induced a new function for the object as an ad-hoc affordance (e.g., the funnel is glued to the wall and the agent wants to hang the coat), we observed a crossing-over regarding the direction of the N400 effect: comparing the ad-hoc affordance-inducing context with the neutral context, the N400 for the incongruent verb was significantly reduced, whereas the N400 for the congruent verb was significantly enhanced. We explain these results as a consequence of the incorporation of the contextually triggered ad-hoc affordance into the meaning of the noun. Combining these results with an analysis of semantic similarity values between test sentences and contexts, we argue that one possibility is that the incorporation of an ad-hoc affordance may be explained on the basis of the mental simulation of concurrent motor information.

Ad hoc instrumentation methods in ecological studies produce highly biased temperature measurements

USGS Publications Warehouse

Terando, Adam J.; Youngsteadt, Elsa; Meineke, Emily K.; Prado, Sara G.

2017-01-01

In light of global climate change, ecological studies increasingly address effects of temperature on organisms and ecosystems. To measure air temperature at biologically relevant scales in the field, ecologists often use small, portable temperature sensors. Sensors must be shielded from solar radiation to provide accurate temperature measurements, but our review of 18 years of ecological literature indicates that shielding practices vary across studies (when reported at all), and that ecologists often invent and construct ad hoc radiation shields without testing their efficacy. We performed two field experiments to examine the accuracy of temperature observations from three commonly used portable data loggers (HOBO Pro, HOBO Pendant, and iButton hygrochron) housed in manufactured Gill shields or ad hoc, custom‐fabricated shields constructed from everyday materials such as plastic cups. We installed this sensor array (five replicates of 11 sensor‐shield combinations) at weather stations located in open and forested sites. HOBO Pro sensors with Gill shields were the most accurate devices, with a mean absolute error of 0.2°C relative to weather stations at each site. Error in ad hoc shield treatments ranged from 0.8 to 3.0°C, with the largest errors at the open site. We then deployed one replicate of each sensor‐shield combination at five sites that varied in the amount of urban impervious surface cover, which presents a further shielding challenge. Bias in sensors paired with ad hoc shields increased by up to 0.7°C for every 10% increase in impervious surface. Our results indicate that, due to variable shielding practices, the ecological literature likely includes highly biased temperature data that cannot be compared directly across studies. If left unaddressed, these errors will hinder efforts to predict biological responses to climate change. We call for greater standardization in how temperature data are recorded in the field, handled in analyses, and reported in publications.

Trust Management in Mobile Ad Hoc Networks for Bias Minimization and Application Performance Maximization

DTIC Science & Technology

2014-02-26

set of anomaly detection rules 62 I.-R. Chen et al. / Ad Hoc Networks 19 (2014) 59–74 Author’s personal copy including the interval rule (for...deficiencies in anomaly detection (e.g., imperfection of rules) by a false negative probability (PHfn) of misidentifying an unhealthy node as a...multimedia servers, Multimedia Syst. 8 (2) (2000) 83–91. [53] R. Mitchell, I.R. Chen, Adaptive intrusion detection for unmanned aircraft systems based on

Hearings before the Ad Hoc Committee on Maritime Education and Training of the Committee on Merchant Marine and Fisheries, Ninety-Third Congress; Second Session on Officer Requirements, and Session on Maritime Education Regarding Safety at Sea. Serial No. 93-44.

ERIC Educational Resources Information Center

Congress of the U.S., Washington, DC. House Committee on Merchant Marine and Fisheries.

The publication consists of Congressional hearings before the Ad Hoc Committee on Maritime Education and Training: (1) June 26, 1974 hearing pertaining to officer requirements and (2) November 19, 1974 hearing on maritime education regarding safety at sea. Estimated cost per graduate for the U. S. Merchant Marine 1973 class was $31,100. Supply and…

Mapping Ad Hoc Communications Network of a Large Number Fixed-Wing UAV Swarm

DTIC Science & Technology

2017-03-01

partitioned sub-swarms. The work covered in this thesis is to build a model of the NPS swarm’s communication network in ns-3 simulation software and use...partitioned sub- swarms. The work covered in this thesis is to build a model of the NPS swarm’s communication network in ns-3 simulation software and...NAVAL POSTGRADUATE SCHOOL MONTEREY, CALIFORNIA THESIS MAPPING AD HOC COMMUNICATIONS NETWORK OF A LARGE NUMBER FIXED-WING UAV SWARM by Alexis

Use of synthesized data to support complex ad-hoc queries in an enterprise information warehouse: a diabetes use case.

PubMed

Rogers, Patrick; Erdal, Selnur; Santangelo, Jennifer; Liu, Jianhua; Schuster, Dara; Kamal, Jyoti

2008-11-06

The Ohio State University Medical Center (OSUMC) Information Warehouse (IW) is a comprehensive data warehousing facility incorporating operational, clinical, and biological data sets from multiple enterprise system. It is common for users of the IW to request complex ad-hoc queries that often require significant intervention by data analyst. In response to this challenge, we have designed a workflow that leverages synthesized data elements to support such queries in an more timely, efficient manner.

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

Ad Hoc Conference on the Education of Migrants: Introductory Report on Theme I, "The Position of the Immigrant and His Family on Arrival in the Host Country" (Strasbourg, France, November 5-8, 1974).

ERIC Educational Resources Information Center

Morin, Emma

Theme I of the Ad Hoc Conference on the Education of Migrants was "measures to improve the position of the immigrant and his family at the time of arrival in the host country (including measures taken in the sending country on behalf of those intending to emigrate), primarily in respect of their educational circumstances". This report…

The Public Understanding of Science. Report of a Royal Society ad hoc Group Endorsed by the Council of the Royal Society.

ERIC Educational Resources Information Center

Royal Society, London (England).

Based on the premise that science and technology directly affect a wide range of personal activities and impact policy issues of national and international importance, this report aims to show why it matters that all sections of the public should have some understanding of science and to stimulate action by scientists and others to improve this…

Ad Hoc Information Extraction for Clinical Data Warehouses.

PubMed

Dietrich, Georg; Krebs, Jonathan; Fette, Georg; Ertl, Maximilian; Kaspar, Mathias; Störk, Stefan; Puppe, Frank

2018-05-01

Clinical Data Warehouses (CDW) reuse Electronic health records (EHR) to make their data retrievable for research purposes or patient recruitment for clinical trials. However, much information are hidden in unstructured data like discharge letters. They can be preprocessed and converted to structured data via information extraction (IE), which is unfortunately a laborious task and therefore usually not available for most of the text data in CDW. The goal of our work is to provide an ad hoc IE service that allows users to query text data ad hoc in a manner similar to querying structured data in a CDW. While search engines just return text snippets, our systems also returns frequencies (e.g. how many patients exist with "heart failure" including textual synonyms or how many patients have an LVEF < 45) based on the content of discharge letters or textual reports for special investigations like heart echo. Three subtasks are addressed: (1) To recognize and to exclude negations and their scopes, (2) to extract concepts, i.e. Boolean values and (3) to extract numerical values. We implemented an extended version of the NegEx-algorithm for German texts that detects negations and determines their scope. Furthermore, our document oriented CDW PaDaWaN was extended with query functions, e.g. context sensitive queries and regex queries, and an extraction mode for computing the frequencies for Boolean and numerical values. Evaluations in chest X-ray reports and in discharge letters showed high F1-scores for the three subtasks: Detection of negated concepts in chest X-ray reports with an F1-score of 0.99 and in discharge letters with 0.97; of Boolean values in chest X-ray reports about 0.99, and of numerical values in chest X-ray reports and discharge letters also around 0.99 with the exception of the concept age. The advantages of an ad hoc IE over a standard IE are the low development effort (just entering the concept with its variants), the promptness of the results and the adaptability by the user to his or her particular question. Disadvantage are usually lower accuracy and confidence.This ad hoc information extraction approach is novel and exceeds existing systems: Roogle [1] extracts predefined concepts from texts at preprocessing and makes them retrievable at runtime. Dr. Warehouse [2] applies negation detection and indexes the produced subtexts which include affirmed findings. Our approach combines negation detection and the extraction of concepts. But the extraction does not take place during preprocessing, but at runtime. That provides an ad hoc, dynamic, interactive and adjustable information extraction of random concepts and even their values on the fly at runtime. We developed an ad hoc information extraction query feature for Boolean and numerical values within a CDW with high recall and precision based on a pipeline that detects and removes negations and their scope in clinical texts. Schattauer GmbH.

The utility of the Dementia Severity Rating Scale in differentiating mild cognitive impairment and Alzheimer disease from controls.

PubMed

Mitchell, Joel C; Dick, Malcolm B; Wood, Amanda E; Tapp, Andre M; Ziegler, Raphael

2015-01-01

The current study investigated the utility of the Dementia Severity Rating Scale (DSRS) total score to identify individuals at the earliest stage of impairment (ie, mild cognitive impairment/MCI). In addition, the authors sought to investigate how well the measure correlates with an expanded battery of cognitive tests and other measures of functional abilities. Of the 320 participants included in this study, 85 were normal controls, 96 had single-domain or multiple-domain amnestic MCI, and 139 had possible or probable Alzheimer disease (AD). Each participant underwent a thorough cognitive, neurological, and physical examination. Results from this study indicated that the DSRS total scores differed significantly between the 3 groups (P<0.001) and accurately identified 81% of the control group, 60% of the MCI group, and 78% of the AD group in a post hoc discriminant analysis. When combined with a brief cognitive measure (ie, Consortium to Establish a Registry for Alzheimer's Disease Word List 5 min recall test), the DSRS accurately identified 98% of the control group, 76% of the MCI group, and 82% of the AD group. Implications for clinical practice and proposed areas of future research are discussed.

Adaptive Reliable Routing Protocol Using Combined Link Stability Estimation for Mobile Ad hoc Networks

NASA Astrophysics Data System (ADS)

Vadivel, R.; Bhaskaran, V. Murali

2010-10-01

The main reason for packet loss in ad hoc networks is the link failure or node failure. In order to increase the path stability, it is essential to distinguish and moderate the failures. By knowing individual link stability along a path, path stability can be identified. In this paper, we develop an adaptive reliable routing protocol using combined link stability estimation for mobile ad hoc networks. The main objective of this protocol is to determine a Quality of Service (QoS) path along with prolonging the network life time and to reduce the packet loss. We calculate a combined metric for a path based on the parameters Link Expiration Time, Node Remaining Energy and Node Velocity and received signal strength to predict the link stability or lifetime. Then, a bypass route is established to retransmit the lost data, when a link failure occurs. By simulation results, we show that the proposed reliable routing protocol achieves high delivery ratio with reduced delay and packet drop.

An Optimal CDS Construction Algorithm with Activity Scheduling in Ad Hoc Networks

PubMed Central

Penumalli, Chakradhar; Palanichamy, Yogesh

2015-01-01

A new energy efficient optimal Connected Dominating Set (CDS) algorithm with activity scheduling for mobile ad hoc networks (MANETs) is proposed. This algorithm achieves energy efficiency by minimizing the Broadcast Storm Problem [BSP] and at the same time considering the node's remaining energy. The Connected Dominating Set is widely used as a virtual backbone or spine in mobile ad hoc networks [MANETs] or Wireless Sensor Networks [WSN]. The CDS of a graph representing a network has a significant impact on an efficient design of routing protocol in wireless networks. Here the CDS is a distributed algorithm with activity scheduling based on unit disk graph [UDG]. The node's mobility and residual energy (RE) are considered as parameters in the construction of stable optimal energy efficient CDS. The performance is evaluated at various node densities, various transmission ranges, and mobility rates. The theoretical analysis and simulation results of this algorithm are also presented which yield better results. PMID:26221627

On knowledge transfer management as a learning process for ad hoc teams

NASA Astrophysics Data System (ADS)

Iliescu, D.

2017-08-01

Knowledge management represents an emerging domain becoming more and more important. Concepts like knowledge codification and personalisation, knowledge life-cycle, social and technological dimensions, knowledge transfer and learning management are integral parts. Focus goes here in the process of knowledge transfer for the case of ad hoc teams. The social dimension of knowledge transfer plays an important role. No single individual actors involved in the process, but a collective one, representing the organisation. It is critically important for knowledge to be managed from the life-cycle point of view. A complex communication network needs to be in place to supports the process of knowledge transfer. Two particular concepts, the bridge tie and transactive memory, would eventually enhance the communication. The paper focuses on an informational communication platform supporting the collaborative work on knowledge transfer. The platform facilitates the creation of a topic language to be used in knowledge modelling, storage and reuse, by the ad hoc teams.

On Trust Evaluation in Mobile Ad Hoc Networks

NASA Astrophysics Data System (ADS)

Nguyen, Dang Quan; Lamont, Louise; Mason, Peter C.

Trust has been considered as a social relationship between two individuals in human society. But, as computer science and networking have succeeded in using computers to automate many tasks, the concept of trust can be generalized to cover the reliability and relationships of non-human interaction, such as, for example, information gathering and data routing. This paper investigates the evaluation of trust in the context of ad hoc networks. Nodes evaluate each other’s behaviour based on observables. A node then decides whether to trust another node to have certain innate abilities. We show how accurate such an evaluation could be. We also provide the minimum number of observations required to obtain an accurate evaluation, a result that indicates that observation-based trust in ad hoc networks will remain a challenging problem. The impact of making networking decisions using trust evaluation on the network connectivity is also examined. In this manner, quantitative decisions can be made concerning trust-based routing with the knowledge of the potential impact on connectivity.

Evaluation and development the routing protocol of a fully functional simulation environment for VANETs

NASA Astrophysics Data System (ADS)

Ali, Azhar Tareq; Warip, Mohd Nazri Mohd; Yaakob, Naimah; Abduljabbar, Waleed Khalid; Atta, Abdu Mohammed Ali

2017-11-01

Vehicular Ad-hoc Networks (VANETs) is an area of wireless technologies that is attracting a great deal of interest. There are still several areas of VANETS, such as security and routing protocols, medium access control, that lack large amounts of research. There is also a lack of freely available simulators that can quickly and accurately simulate VANETs. The main goal of this paper is to develop a freely available VANETS simulator and to evaluate popular mobile ad-hoc network routing protocols in several VANETS scenarios. The VANETS simulator consisted of a network simulator, traffic (mobility simulator) and used a client-server application to keep the two simulators in sync. The VANETS simulator also models buildings to create a more realistic wireless network environment. Ad-Hoc Distance Vector routing (AODV), Dynamic Source Routing (DSR) and Dynamic MANET On-demand (DYMO) were initially simulated in a city, country, and highway environment to provide an overall evaluation.

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

Yang, Dr. Li; Cui, Xiaohui; Cemerlic, Alma

Ad hoc networks are very helpful in situations when no fixed network infrastructure is available, such as natural disasters and military conflicts. In such a network, all wireless nodes are equal peers simultaneously serving as both senders and routers for other nodes. Therefore, how to route packets through reliable paths becomes a fundamental problems when behaviors of certain nodes deviate from wireless ad hoc routing protocols. We proposed a novel Dirichlet reputation model based on Bayesian inference theory which evaluates reliability of each node in terms of packet delivery. Our system offers a way to predict and select a reliablemore » path through combination of first-hand observation and second-hand reputation reports. We also proposed moving window mechanism which helps to adjust ours responsiveness of our system to changes of node behaviors. We integrated the Dirichlet reputation into routing protocol of wireless ad hoc networks. Our extensive simulation indicates that our proposed reputation system can improve good throughput of the network and reduce negative impacts caused by misbehaving nodes.« less

Sputnik: ad hoc distributed computation.

PubMed

Völkel, Gunnar; Lausser, Ludwig; Schmid, Florian; Kraus, Johann M; Kestler, Hans A

2015-04-15

In bioinformatic applications, computationally demanding algorithms are often parallelized to speed up computation. Nevertheless, setting up computational environments for distributed computation is often tedious. Aim of this project were the lightweight ad hoc set up and fault-tolerant computation requiring only a Java runtime, no administrator rights, while utilizing all CPU cores most effectively. The Sputnik framework provides ad hoc distributed computation on the Java Virtual Machine which uses all supplied CPU cores fully. It provides a graphical user interface for deployment setup and a web user interface displaying the current status of current computation jobs. Neither a permanent setup nor administrator privileges are required. We demonstrate the utility of our approach on feature selection of microarray data. The Sputnik framework is available on Github http://github.com/sysbio-bioinf/sputnik under the Eclipse Public License. hkestler@fli-leibniz.de or hans.kestler@uni-ulm.de Supplementary data are available at Bioinformatics online. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

A multihop key agreement scheme for wireless ad hoc networks based on channel characteristics.

PubMed

Hao, Zhuo; Zhong, Sheng; Yu, Nenghai

2013-01-01

A number of key agreement schemes based on wireless channel characteristics have been proposed recently. However, previous key agreement schemes require that two nodes which need to agree on a key are within the communication range of each other. Hence, they are not suitable for multihop wireless networks, in which nodes do not always have direct connections with each other. In this paper, we first propose a basic multihop key agreement scheme for wireless ad hoc networks. The proposed basic scheme is resistant to external eavesdroppers. Nevertheless, this basic scheme is not secure when there exist internal eavesdroppers or Man-in-the-Middle (MITM) adversaries. In order to cope with these adversaries, we propose an improved multihop key agreement scheme. We show that the improved scheme is secure against internal eavesdroppers and MITM adversaries in a single path. Both performance analysis and simulation results demonstrate that the improved scheme is efficient. Consequently, the improved key agreement scheme is suitable for multihop wireless ad hoc networks.

Modern foreign language teachers - don't leave those kids alone! Linguistic-cultural "give and take" in an ad-hoc tutoring scheme

NASA Astrophysics Data System (ADS)

Leroy, Norah

2017-08-01

This paper addresses the theme of social inclusion through language learning. The focus is on an ad-hoc tutoring scheme set up between newly arrived British migrant pupils and French monolingual pupils in a small secondary school in the south-west of France. Though the original objective of this tutoring scheme was to improve the English skills of the younger pupils, feedback reports indicated that it also had a positive impact on the relationship between the British migrant pupils and their French peers. Teachers believed that those involved participated more fully in class, and appeared more self-assured and generally happy thanks to the interpersonal relationships this scheme helped to forge. This study demonstrates the necessity of analysing the socio-cultural context migrants may find themselves in, in order to identify potential challenges. The ad-hoc tutoring scheme described here is an example of how language learning can support the integration and inclusion of "new generation" migrants into everyday school life.

Performance Evaluation of AODV with Blackhole Attack

NASA Astrophysics Data System (ADS)

Dara, Karuna

2010-11-01

A Mobile Ad Hoc Network (MANET) is a temporary network set up by a wireless mobile computers moving arbitrary in the places that have no network infrastructure. These nodes maintain connectivity in a decentralized manner. Since the nodes communicate with each other, they cooperate by forwarding data packets to other nodes in the network. Thus the nodes find a path to the destination node using routing protocols. However, due to security vulnerabilities of the routing protocols, mobile ad-hoc networks are unprotected to attacks of the malicious nodes. One of these attacks is the Black Hole Attack against network integrity absorbing all data packets in the network. Since the data packets do not reach the destination node on account of this attack, data loss will occur. In this paper, we simulated the black hole attack in various mobile ad-hoc network scenarios using AODV routing protocol of MANET and have tried to find a effect if number of nodes are increased with increase in malicious nodes.

A Multihop Key Agreement Scheme for Wireless Ad Hoc Networks Based on Channel Characteristics

PubMed Central

Yu, Nenghai

2013-01-01

A number of key agreement schemes based on wireless channel characteristics have been proposed recently. However, previous key agreement schemes require that two nodes which need to agree on a key are within the communication range of each other. Hence, they are not suitable for multihop wireless networks, in which nodes do not always have direct connections with each other. In this paper, we first propose a basic multihop key agreement scheme for wireless ad hoc networks. The proposed basic scheme is resistant to external eavesdroppers. Nevertheless, this basic scheme is not secure when there exist internal eavesdroppers or Man-in-the-Middle (MITM) adversaries. In order to cope with these adversaries, we propose an improved multihop key agreement scheme. We show that the improved scheme is secure against internal eavesdroppers and MITM adversaries in a single path. Both performance analysis and simulation results demonstrate that the improved scheme is efficient. Consequently, the improved key agreement scheme is suitable for multihop wireless ad hoc networks. PMID:23766725

76 FR 70984 - National Assessment Governing Board; Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-16

... be discussed/disclosed in an open meeting. Premature disclosure of these secure test items and... Education, National Assessment Governing Board. ACTION: Notice of Open and Closed Meeting Sessions. SUMMARY... Hoc, Assessment Development, and Executive Committee. Meetings Ad Hoc Committee: Open Session: 8:30 a...

Organizational culture during the accident response process

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

Shurberg, D.A.; Haber, S.B.

1992-01-01

The ability of an organization to effectively move from an anticipatory to an ad hoc strategy may well depend on the organization having the ability to balance these two apparently dichotomous cultural styles. The organization which is most capable of making the necessary transition in an optimal manner may well exhibit some aspects of both cultural styles during normal operations. Data collected at one NPP does exhibit this pattern of results, with the organization exhibiting a clear hierarchical chain of command and perceived conventional behavioral expectations as well as exhibiting a more decentralized and collegial approach to decisionmaking, a teammore » work orientation, and informal communications. Thus, it is expected that this organization possesses the capabilities to make a successful transition from an anticipatory to an ad hoc strategy. Data collected at a second NPP more strongly exhibits the traditional style suggested as being important during the anticipatory strategy, with more formal communications and bureaucratically controlled decision-making. This organization may experience difficulty if faced with the need to make a transition from an anticipatory to an ad hoc strategy. These conclusions are further validated based on observation of Emergency Preparedness Exercise Inspections, which suggest that the more anticipatory types of behaviors actually inhibit successful performance during an ad hoc response. The final validation of these hypotheses needs to be demonstrated with cultural data collected during emergency simulations. The mechanism to obtain such data during these types of situations is an area for future research.« less

Organizational culture during the accident response process

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

Shurberg, D.A.; Haber, S.B.

1992-08-01

The ability of an organization to effectively move from an anticipatory to an ad hoc strategy may well depend on the organization having the ability to balance these two apparently dichotomous cultural styles. The organization which is most capable of making the necessary transition in an optimal manner may well exhibit some aspects of both cultural styles during normal operations. Data collected at one NPP does exhibit this pattern of results, with the organization exhibiting a clear hierarchical chain of command and perceived conventional behavioral expectations as well as exhibiting a more decentralized and collegial approach to decisionmaking, a teammore » work orientation, and informal communications. Thus, it is expected that this organization possesses the capabilities to make a successful transition from an anticipatory to an ad hoc strategy. Data collected at a second NPP more strongly exhibits the traditional style suggested as being important during the anticipatory strategy, with more formal communications and bureaucratically controlled decision-making. This organization may experience difficulty if faced with the need to make a transition from an anticipatory to an ad hoc strategy. These conclusions are further validated based on observation of Emergency Preparedness Exercise Inspections, which suggest that the more anticipatory types of behaviors actually inhibit successful performance during an ad hoc response. The final validation of these hypotheses needs to be demonstrated with cultural data collected during emergency simulations. The mechanism to obtain such data during these types of situations is an area for future research.« less

Ad hoc supervision of general practice registrars as a 'community of practice': analysis, interpretation and re-presentation.

PubMed

Clement, T; Brown, J; Morrison, J; Nestel, D

2016-05-01

General practice registrars in Australia undertake most of their vocational training in accredited general practices. They typically see patients alone from the start of their community-based training and are expected to seek timely ad hoc support from their supervisor. Such ad hoc encounters are a mechanism for ensuring patient safety, but also provide an opportunity for learning and teaching. Wenger's (Communities of practice: learning, meaning, and identity. Cambridge University Press, New York, 1998) social theory of learning ('communities of practice') guided a secondary analysis of audio-recordings of ad hoc encounters. Data from one encounter is re-presented as an extended sequence to maintain congruence with the theoretical perspective and enhance vicariousness. An interpretive commentary communicates key features of Wenger's theory and highlights the researchers' interpretations. We argue that one encounter can reveal universal understandings of clinical supervision and that the process of naturalistic generalisation allows readers to transfer others' experiences to their own contexts. The paper raises significant analytic, interpretive, and representational issues. We highlight that report writing is an important, but infrequently discussed, part of research design. We discuss the challenges of supporting the learning and teaching that arises from adopting a socio-cultural lens and argue that such a perspective importantly captures the complex range of issues that work-based practitioners have to grapple with. This offers a challenge to how we research and seek to influence work-based learning and teaching in health care settings.

Wireless Sensor Network Quality of Service Improvement on Flooding Attack Condition

NASA Astrophysics Data System (ADS)

Hartono, R.; Widyawan; Wibowo, S. B.; Purnomo, A.; Hartatik

2018-03-01

There are two methods of building communication using wireless media. The first method is building a base infrastructure as an intermediary between users. Problems that arise on this type of network infrastructure is limited space to build any network physical infrastructure and also the cost factor. The second method is to build an ad hoc network between users who will communicate. On ad hoc network, each user must be willing to send data from source to destination for the occurrence of a communication. One of network protocol in Ad Hoc, Ad hoc on demand Distance Vector (AODV), has the smallest overhead value, easier to adapt to dynamic network and has small control message. One AODV protocol’s drawback is route finding process’ security for sending the data. In this research, AODV protocol is optimized by determining Expanding Ring Search (ERS) best value. Random topology is used with variation in the number of nodes: 25, 50, 75, 100, 125 and 150 with node’s speed of 10m/s in the area of 1000m x 1000m on flooding network condition. Parameters measured are Throughput, Packet Delivery Ratio, Average Delay and Normalized Routing Load. From the test results of AODV protocol optimization with best value of Expanding Ring Search (ERS), throughput increased by 5.67%, packet delivery ratio increased by 5.73%, and as for Normalized Routing Load decreased by 4.66%. ERS optimal value for each node’s condition depending on the number of nodes on the network.

Assessing the State-of-the-Art in Dynamic Discovery of Ad Hoc Network Services

DTIC Science & Technology

2001-07-18

directed -- discovery mode. It is part of the SCM_Discovery -- Module. Sends Unicast messages to SCMs on list of -- SCMS to be discovered until all... SCMS are found. -- Receives updates from SCM DB of discovered SCMs and -- removes SCMs accordingly -- NOTE: Failure and recovery behavior are not...ALLFindService10 SM4 GROUP1GroupJoin10 SCM1 SM4LinkFail5 SM4NodeFail5 ParametersCommandTime TopologyScenario Execute with Rapide For All (SM, SD, SCM

OECD/NEA study on the economics of the long-term operation of nuclear power plants

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

Lokhov, A.; Cameron, R.

2012-07-01

The OECD Nuclear Energy Agency (NEA) established the Ad hoc expert group on the Economics of Long-term Operation (LTO) of Nuclear Power Plants. The primary aim of this group is to collect and analyse technical and economic data on the upgrade and lifetime extension experience in OECD countries, and to assess the likely applications for future extensions. This paper describes the key elements of the methodology of economic assessment of LTO and initial findings for selected NEA member countries. (authors)

Shortened cortical silent period in adductor spasmodic dysphonia: evidence for widespread cortical excitability.

PubMed

Samargia, Sharyl; Schmidt, Rebekah; Kimberley, Teresa Jacobson

2014-02-07

The purpose of this study was to compare cortical inhibition in the hand region of the primary motor cortex between subjects with focal hand dystonia (FHD), adductor spasmodic dysphonia (AdSD), and healthy controls. Data from 28 subjects were analyzed (FHD n=11, 53.25 ± 8.74 y; AdSD: n=8, 56.38 ± 7.5 y; and healthy controls: n=941.67 ± 10.85 y). All subjects received single pulse TMS to the left motor cortex to measure cortical silent period (CSP) in the right first dorsal interosseus (FDI) muscle. Duration of the CSP was measured and compared across groups. A one-way ANCOVA with age as a covariate revealed a significant group effect (p<0.001). Post hoc analysis revealed significantly longer CSP duration in the healthy group vs. AdSD group (p<0.001) and FHD group (p<0.001). These results suggest impaired intracortical inhibition is a neurophysiologic characteristic of FHD and AdSD. In addition, the shortened CSP in AdSD provides evidence to support a widespread decrease in cortical inhibition in areas of the motor cortex that represent an asymptomatic region of the body. These findings may inform future investigations of differential diagnosis as well as alternative treatments for focal dystonias. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Network Centric Communications for Expeditionary or Carrier Strike Groups

DTIC Science & Technology

2011-12-01

known as Modulating Retroreflector (MRR) mode. In this configuration, a source laser transmits a beam to an optical receiver which receives the...be adapted for use at sea and found that interference was a key issue. SPAWAR Systems Center Pacific has spent over a decade trying to address this...ad-hoc wireless technology non-proprietary and radio agnostic. One of the issues with wireless technologies used at sea is the issue of ― beam

Screening for Cerebroprotective Agents Using an In Vivo Model of Cerebral Reversible Depolarization in Awake Rats

DTIC Science & Technology

2001-01-01

next millennium. Roach RC, Wagner pathophysiology and therapy . Neurosci Biobehav Res 1987; 11: PD, Hackett PH, eds. New York: Kluwer Academic/Plenum 287...Medical 43. Anonymous. Neuroprotection as initial therapy in acute Publishers, 1989. stroke. Third report of an ad hoc consensus group meeting. The 19...metabolism during electroconvulsive treatment in relaxation. rotoxicity risk assessment. In: Neuroprotective agents, vol. 825. EEG-EMG Zeitschrift fur

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

Towards Trust-based Cognitive Networks: A Survey of Trust Management for Mobile Ad Hoc Networks

DTIC Science & Technology

2009-06-01

of trust. First, social trust refers to properties derived from social relationships . Examples of social networks are strong social ... relationships such as colleagues or relatives or loose social relationships such as school alumni or friends with common interests [44]. Social trust may...also use social relationships in evaluating the trust metric among group members by employing the concept of social networks. Yu et al. [44] define

Ad hoc versus standardized admixtures for continuous infusion drugs in neonatal intensive care: cognitive task analysis of safety at the bedside.

PubMed

Brannon, Timothy S

2006-01-01

Continuous infusion intravenous (IV) drugs in neonatal intensive care are usually prepared based on patient weight so that the dose is readable as a simple multiple of the infusion pump rate. New safety guidelines propose that hospitals switch to using standardized admixtures of these drugs to prevent calculation errors during ad hoc preparation. Extended hierarchical task analysis suggests that switching to standardized admixtures may lead to more errors in programming the pump at the bedside.

Ad Hoc versus Standardized Admixtures for Continuous Infusion Drugs in Neonatal Intensive Care: Cognitive Task Analysis of Safety at the Bedside

PubMed Central

Brannon, Timothy S.

2006-01-01

Continuous infusion intravenous (IV) drugs in neonatal intensive care are usually prepared based on patient weight so that the dose is readable as a simple multiple of the infusion pump rate. New safety guidelines propose that hospitals switch to using standardized admixtures of these drugs to prevent calculation errors during ad hoc preparation. Extended hierarchical task analysis suggests that switching to standardized admixtures may lead to more errors in programming the pump at the bedside. PMID:17238482

Ad Hoc Networking for Unmanned Ground Vehicles: Design and Evaluation at Command, Control, Communications, Intelligence, Surveillance and Reconnaissance On-the-Move

DTIC Science & Technology

2006-11-01

software components used in the ad hoc nodes for the C4ISR OTM experiment were OLSRD, an open-source proactive MANET routing software, and OpenVPN , an...developed by Mike Baker (openwrt.org). 6OpenVPN is a trademark of OpenVPN Solutions LLC. 6 Secure communications in the MANET are achieved with...encryption provided by Wired Equivalent Privacy (WEP) and OpenVPN . The WEP protocol, which is part of the IEEE 802.11 wireless networking standard

Power-Aware Intrusion Detection in Mobile Ad Hoc Networks

NASA Astrophysics Data System (ADS)

Şen, Sevil; Clark, John A.; Tapiador, Juan E.

Mobile ad hoc networks (MANETs) are a highly promising new form of networking. However they are more vulnerable to attacks than wired networks. In addition, conventional intrusion detection systems (IDS) are ineffective and inefficient for highly dynamic and resource-constrained environments. Achieving an effective operational MANET requires tradeoffs to be made between functional and non-functional criteria. In this paper we show how Genetic Programming (GP) together with a Multi-Objective Evolutionary Algorithm (MOEA) can be used to synthesise intrusion detection programs that make optimal tradeoffs between security criteria and the power they consume.

Panel Discussion : Report of the APS Ad-Hoc Committee on LGBT Issues

NASA Astrophysics Data System (ADS)

Atherton, Tim; Barthelemy, Ramon; Garmon, Savannah; Reeves, Kyle; APS Ad-Hoc Committee on LGBT Issues Team

Following the presentation of the findings and recommendations of the APS Ad-Hoc Committee on LGBT Issues (C-LGBT) by Committee Chair Michael Falk, a panel discussion will be held featuring several members of the committee. The discussion will focus on how APS can best ensure the recommendations of the committee are carried out in a timely fashion and other ideas on future APS efforts toward LGBT inclusion in physics. Discussion topics will also include the research and other input that shaped the committee's findings and recommendations.

Mathematical representation of joint time-chroma distributions

NASA Astrophysics Data System (ADS)

Wakefield, Gregory H.

1999-11-01

Originally coined by the sensory psychologist Roger Shepard in the 1960s, chroma transforms frequency into octave equivalence classes. By extending the concept of chroma to chroma strength and how it varies over time, we have demonstrated the utility of chroma in simplifying the processing and representation of signals dominated by harmonically-related narrowband components. These investigations have utilized an ad hoc procedure for calculating the chromagram from a given time-frequency distribution. The present paper is intended to put this ad hoc procedure on more sound mathematical ground.

The unannounced patient in the corridor: trust, friction and person-centered care.

PubMed

Carlström, Eric D; Hansson Olofsson, Elisabeth; Olsson, Lars-Eric; Nyman, Jan; Koinberg, Inga-Lill

2017-01-01

In this study, a Swedish cancer clinic was studied where three to four unscheduled patients sought support from the hospital on a daily basis for pain and nutrition problems. The clinic was neither staffed nor had a budget to handle such return visits. In order to offer the patients a better service and decrease the workload of the staff in addition to their everyday activities, a multidisciplinary team was established to address the unscheduled return visits. The team was supposed to involve the patient, build trust, decrease the friction, and contribute to a successful rehabilitation process. Data were collected from the patients and the staff. Patients who encountered the team (intervention) and patients who encountered the regular ad hoc type of organization (control) answered a questionnaire measuring trust and friction. Nurses in the control group spent 35% of their full-time employment, and the intervention group staffed with nurses spent 30% of their full-time employment in addressing the needs of these return patients. The patients perceived that trust between them and the staff was high. In summary, it was measured as being 4.48 [standard deviation (SD) = 0.82] in the intervention group and 4.41 (SD = 0.79) in the control group using the 5-point Likert scale. The data indicate that using a multidisciplinary team is a promising way to handle the problems of unannounced visits from patients. Having a team made it cost effective for the clinic and provided a better service than the traditional ad hoc organization. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

Capitalizing on Education and Outreach (E/O) Expertise to Broaden Impacts (Invited)

NASA Astrophysics Data System (ADS)

Girguis, P. R.; Herren, C.; Decharon, A.

2010-12-01

Academic scientists have a number of avenues through which they can participate in education and outreach (E/O) programs to address the mandate for broader impacts. As a principal investigator (PI) at an R1 institution, I (Girguis) have both developed and participated in a variety of E/O programs that span the spectrum from ad hoc groups (e.g. informal high school internships in my laboratory) to regional efforts (e.g. Harvard’s Microbial Science Initiative) and national organizations (e.g. RIDGE 2000; Centers for Ocean Sciences Education Excellence, COSEE). Each of these E/O efforts required varying degrees of preparation and participation by my laboratory members (e.g. graduate students and postdoctoral researchers) and I, and yielded different outcomes and products. Ad hoc programs typically require a higher degree of effort on the part of the PI and have a high, though local, impact on the audience. These programs can be personally rewarding for the PI, who likely has played a major role in developing the program. In contrast, working with regional and national groups requires PIs to understand the nature of each program to successfully integrate within the existing structure. The net time and effort invested by scientists in larger-scale E/O efforts may be equal to that of ad hoc programs. However, interaction with high-quality program facilitators ensures that the outcomes are grounded in best educational practices and that outputs are educator-vetted, well maintained (online or through publications), and broadly disseminated. In addition, program facilitators also collect and analyze evaluation data to provide constructive feedback to PIs, enabling the latter to refine their presentation styles and content levels to improve future E/O efforts. Thus involvement with larger programs can effectively broaden one’s impact. During this presentation, we will present one scientist’s perspective on the advantages and limitations of these different modes of E/O, including specific examples from the past three years of working with COSEE-Ocean Systems. We will share “lessons learned” regarding the efficacy of these various modes of E/O, and will also discuss those factors that influence a PI’s decision to participate in E/O programs.

Latency-Efficient Communication in Wireless Mesh Networks under Consideration of Large Interference Range

NASA Astrophysics Data System (ADS)

Xin, Qin; Yao, Xiaolan; Engelstad, Paal E.

2010-09-01

Wireless Mesh Networking is an emerging communication paradigm to enable resilient, cost-efficient and reliable services for the future-generation wireless networks. We study here the minimum-latency communication primitive of gossiping (all-to-all communication) in multi-hop ad-hoc Wireless Mesh Networks (WMNs). Each mesh node in the WMN is initially given a message and the objective is to design a minimum-latency schedule such that each mesh node distributes its message to all other mesh nodes. Minimum-latency gossiping problem is well known to be NP-hard even for the scenario in which the topology of the WMN is known to all mesh nodes in advance. In this paper, we propose a new latency-efficient approximation scheme that can accomplish gossiping task in polynomial time units in any ad-hoc WMN under consideration of Large Interference Range (LIR), e.g., the interference range is much larger than the transmission range. To the best of our knowledge, it is first time to investigate such a scenario in ad-hoc WMNs under LIR, our algorithm allows the labels (e.g., identifiers) of the mesh nodes to be polynomially large in terms of the size of the WMN, which is the first time that the scenario of large labels has been considered in ad-hoc WMNs under LIR. Furthermore, our gossiping scheme can be considered as a framework which can be easily implied to the scenario under consideration of mobility-related issues since we assume that the mesh nodes have no knowledge on the network topology even for its neighboring mesh nodes.

Dynamic autonomous routing technology for IP-based satellite ad hoc networks

NASA Astrophysics Data System (ADS)

Wang, Xiaofei; Deng, Jing; Kostas, Theresa; Rajappan, Gowri

2014-06-01

IP-based routing for military LEO/MEO satellite ad hoc networks is very challenging due to network and traffic heterogeneity, network topology and traffic dynamics. In this paper, we describe a traffic priority-aware routing scheme for such networks, namely Dynamic Autonomous Routing Technology (DART) for satellite ad hoc networks. DART has a cross-layer design, and conducts routing and resource reservation concurrently for optimal performance in the fluid but predictable satellite ad hoc networks. DART ensures end-to-end data delivery with QoS assurances by only choosing routing paths that have sufficient resources, supporting different packet priority levels. In order to do so, DART incorporates several resource management and innovative routing mechanisms, which dynamically adapt to best fit the prevailing conditions. In particular, DART integrates a resource reservation mechanism to reserve network bandwidth resources; a proactive routing mechanism to set up non-overlapping spanning trees to segregate high priority traffic flows from lower priority flows so that the high priority flows do not face contention from low priority flows; a reactive routing mechanism to arbitrate resources between various traffic priorities when needed; a predictive routing mechanism to set up routes for scheduled missions and for anticipated topology changes for QoS assurance. We present simulation results showing the performance of DART. We have conducted these simulations using the Iridium constellation and trajectories as well as realistic military communications scenarios. The simulation results demonstrate DART's ability to discriminate between high-priority and low-priority traffic flows and ensure disparate QoS requirements of these traffic flows.

An extended smart utilization medium access control (ESU-MAC) protocol for ad hoc wireless systems

NASA Astrophysics Data System (ADS)

Vashishtha, Jyoti; Sinha, Aakash

2006-05-01

The demand for spontaneous setup of a wireless communication system has increased in recent years for areas like battlefield, disaster relief operations etc., where a pre-deployment of network infrastructure is difficult or unavailable. A mobile ad-hoc network (MANET) is a promising solution, but poses a lot of challenges for all the design layers, specifically medium access control (MAC) layer. Recent existing works have used the concepts of multi-channel and power control in designing MAC layer protocols. SU-MAC developed by the same authors, efficiently uses the 'available' data and control bandwidth to send control information and results in increased throughput via decreasing contention on the control channel. However, SU-MAC protocol was limited for static ad-hoc network and also faced the busy-receiver node problem. We present the Extended SU-MAC (ESU-MAC) protocol which works mobile nodes. Also, we significantly improve the scheme of control information exchange in ESU-MAC to overcome the busy-receiver node problem and thus, further avoid the blockage of control channel for longer periods of time. A power control scheme is used as before to reduce interference and to effectively re-use the available bandwidth. Simulation results show that ESU-MAC protocol is promising for mobile, ad-hoc network in terms of reduced contention at the control channel and improved throughput because of channel re-use. Results show a considerable increase in throughput compared to SU-MAC which could be attributed to increased accessibility of control channel and improved utilization of data channels due to superior control information exchange scheme.

A Privacy-Preserving Platform for User-Centric Quantitative Benchmarking

NASA Astrophysics Data System (ADS)

Herrmann, Dominik; Scheuer, Florian; Feustel, Philipp; Nowey, Thomas; Federrath, Hannes

We propose a centralised platform for quantitative benchmarking of key performance indicators (KPI) among mutually distrustful organisations. Our platform offers users the opportunity to request an ad-hoc benchmarking for a specific KPI within a peer group of their choice. Architecture and protocol are designed to provide anonymity to its users and to hide the sensitive KPI values from other clients and the central server. To this end, we integrate user-centric peer group formation, exchangeable secure multi-party computation protocols, short-lived ephemeral key pairs as pseudonyms, and attribute certificates. We show by empirical evaluation of a prototype that the performance is acceptable for reasonably sized peer groups.

An Approach to the Classification of Potential Reserve Additions of Giant Oil Fields of the World

USGS Publications Warehouse

Klett, T.R.; Tennyson, Marilyn E.

2008-01-01

This report contains slides and notes for slides for a presentation given to the Committee on Sustainable Energy and the Ad Hoc Group of Experts on Harmonization of Fossil Energy and Mineral Resources Terminology on 17 October 2007 in Geneva, Switzerland. The presentation describes the U.S. Geological Survey study to characterize and quantify petroleum-reserve additions, and the application of this study to help classify the quantities.

Report of the Army Scientific Advisory Panel Ad Hoc Group on Fire Suppression

DTIC Science & Technology

1975-07-01

initially should be provided a nucleus of a seven- person technical staff composed of one 0-6 combat arme officer as Director, two senior behavioral ...If the suppressee perceives the fire as being reactive to his own behavior then the personal danger factor will be reinforced,1 Fire...that is not periodic hut also not reactive to his behavior may be like periodic fire in its personal threat except more difficult to

Greedy data transportation scheme with hard packet deadlines for wireless ad hoc networks.

PubMed

Lee, HyungJune

2014-01-01

We present a greedy data transportation scheme with hard packet deadlines in ad hoc sensor networks of stationary nodes and multiple mobile nodes with scheduled trajectory path and arrival time. In the proposed routing strategy, each stationary ad hoc node en route decides whether to relay a shortest-path stationary node toward destination or a passing-by mobile node that will carry closer to destination. We aim to utilize mobile nodes to minimize the total routing cost as far as the selected route can satisfy the end-to-end packet deadline. We evaluate our proposed routing algorithm in terms of routing cost, packet delivery ratio, packet delivery time, and usability of mobile nodes based on network level simulations. Simulation results show that our proposed algorithm fully exploits the remaining time till packet deadline to turn into networking benefits of reducing the overall routing cost and improving packet delivery performance. Also, we demonstrate that the routing scheme guarantees packet delivery with hard deadlines, contributing to QoS improvement in various network services.

Greedy Data Transportation Scheme with Hard Packet Deadlines for Wireless Ad Hoc Networks

PubMed Central

Lee, HyungJune

2014-01-01

We present a greedy data transportation scheme with hard packet deadlines in ad hoc sensor networks of stationary nodes and multiple mobile nodes with scheduled trajectory path and arrival time. In the proposed routing strategy, each stationary ad hoc node en route decides whether to relay a shortest-path stationary node toward destination or a passing-by mobile node that will carry closer to destination. We aim to utilize mobile nodes to minimize the total routing cost as far as the selected route can satisfy the end-to-end packet deadline. We evaluate our proposed routing algorithm in terms of routing cost, packet delivery ratio, packet delivery time, and usability of mobile nodes based on network level simulations. Simulation results show that our proposed algorithm fully exploits the remaining time till packet deadline to turn into networking benefits of reducing the overall routing cost and improving packet delivery performance. Also, we demonstrate that the routing scheme guarantees packet delivery with hard deadlines, contributing to QoS improvement in various network services. PMID:25258736

Taxonomic and ad hoc categorization within the two cerebral hemispheres.

PubMed

Shen, Yeshayahu; Aharoni, Bat-El; Mashal, Nira

2015-01-01

A typicality effect refers to categorization which is performed more quickly or more accurately for typical than for atypical members of a given category. Previous studies reported a typicality effect for category members presented in the left visual field/right hemisphere (RH), suggesting that the RH applies a similarity-based categorization strategy. However, findings regarding the typicality effect within the left hemisphere (LH) are less conclusive. The current study tested the pattern of typicality effects within each hemisphere for both taxonomic and ad hoc categories, using words presented to the left or right visual fields. Experiment 1 tested typical and atypical members of taxonomic categories as well as non-members, and Experiment 2 tested typical and atypical members of ad hoc categories as well as non-members. The results revealed a typicality effect in both hemispheres and in both types of categories. Furthermore, the RH categorized atypical stimuli more accurately than did the LH. Our findings suggest that both hemispheres rely on a similarity-based categorization strategy, but the coarse semantic coding of the RH seems to facilitate the categorization of atypical members.

Proactive Alleviation Procedure to Handle Black Hole Attack and Its Version

PubMed Central

Babu, M. Rajesh; Dian, S. Moses; Chelladurai, Siva; Palaniappan, Mathiyalagan

2015-01-01

The world is moving towards a new realm of computing such as Internet of Things. The Internet of Things, however, envisions connecting almost all objects within the world to the Internet by recognizing them as smart objects. In doing so, the existing networks which include wired, wireless, and ad hoc networks should be utilized. Moreover, apart from other networks, the ad hoc network is full of security challenges. For instance, the MANET (mobile ad hoc network) is susceptible to various attacks in which the black hole attacks and its versions do serious damage to the entire MANET infrastructure. The severity of this attack increases, when the compromised MANET nodes work in cooperation with each other to make a cooperative black hole attack. Therefore this paper proposes an alleviation procedure which consists of timely mandate procedure, hole detection algorithm, and sensitive guard procedure to detect the maliciously behaving nodes. It has been observed that the proposed procedure is cost-effective and ensures QoS guarantee by assuring resource availability thus making the MANET appropriate for Internet of Things. PMID:26495430

Proactive Alleviation Procedure to Handle Black Hole Attack and Its Version.

PubMed

Babu, M Rajesh; Dian, S Moses; Chelladurai, Siva; Palaniappan, Mathiyalagan

2015-01-01

The world is moving towards a new realm of computing such as Internet of Things. The Internet of Things, however, envisions connecting almost all objects within the world to the Internet by recognizing them as smart objects. In doing so, the existing networks which include wired, wireless, and ad hoc networks should be utilized. Moreover, apart from other networks, the ad hoc network is full of security challenges. For instance, the MANET (mobile ad hoc network) is susceptible to various attacks in which the black hole attacks and its versions do serious damage to the entire MANET infrastructure. The severity of this attack increases, when the compromised MANET nodes work in cooperation with each other to make a cooperative black hole attack. Therefore this paper proposes an alleviation procedure which consists of timely mandate procedure, hole detection algorithm, and sensitive guard procedure to detect the maliciously behaving nodes. It has been observed that the proposed procedure is cost-effective and ensures QoS guarantee by assuring resource availability thus making the MANET appropriate for Internet of Things.

[Health evaluation of trichloroethylene in indoor air : communication from the German ad-hoc working group on indoor guidelines of the Indoor Air Hygiene Committee and of the states' supreme health authorities].

PubMed

2015-07-01

In the European Hazardous Substances Regulation No 1272/2008 trichloroethylene has been classified as a probable human carcinogen and a suspected mutagen. According to several Committees (German Committee on Hazardous Substances, European Scientific Committee on Occupational Exposure Limits, European Chemicals Agency´s Committee for Risk Assessment (ECHA-RAC)) concentrations of trichloroethylene cytotoxic to renal tubuli may increase the risk to develop renal cancer. At non-cytotoxic concentrations of trichloroethylene a much lower cancer risk may be assumed. Therefore, evaluating the cancer risk to the public following inhalation of trichloroethylene ECHA-RAC has assumed a sublinear exposure-response relationship for carcinogenicity of trichloroethylene. Specifically, ECHA-RAC assessed a cancer risk of 6.4 × 10(- 5) (mg/m(3))(- 1) following life time exposure to trichloroethylene below a NOAEC for renal cytotoxicity of 6 mg trichloroethylene/m(3). Further evaluation yields a life-time risk of 10(- 6) corresponding to 0.02 mg trichloroethylene/m(3). This concentration is well above the reference (e.g. background) concentration of trichloroethylene in indoor air. Consequently the Ad-hoc Working Group on Indoor Guidelines recommends 0.02 mg trichloroethylene/m(3) as a risk-related guideline for indoor air. Measures to reduce exposure are considered inappropriate at concentrations below this guideline.

Enhancement of Beaconless Location-Based Routing with Signal Strength Assistance for Ad-Hoc Networks

NASA Astrophysics Data System (ADS)

Chen, Guowei; Itoh, Kenichi; Sato, Takuro

Routing in Ad-hoc networks is unreliable due to the mobility of the nodes. Location-based routing protocols, unlike other protocols which rely on flooding, excel in network scalability. Furthermore, new location-based routing protocols, like, e. g. BLR [1], IGF [2], & CBF [3] have been proposed, with the feature of not requiring beacons in MAC-layer, which improve more in terms of scalability. Such beaconless routing protocols can work efficiently in dense network areas. However, these protocols' algorithms have no ability to avoid from routing into sparse areas. In this article, historical signal strength has been added as a factor into the BLR algorithm, which avoids routing into sparse area, and consequently improves the global routing efficiency.

Sea Training at Maritime Academies Oversight. Hearings Before the Ad Hoc Select Subcommittee on Maritime Education and Training of the Committee on Merchant Marine and Fisheries, House of Representatives, Ninety-Sixth Congress, Second Session on Sea Training of United States Merchant Marine Officers and Different Ways of Satisfying This Requirement at the Various Maritime Academies.

ERIC Educational Resources Information Center

Congress of the U.S., Washington, DC. House Committee on Merchant Marine and Fisheries.

Recorded are minutes of hearings before the House Ad Hoc Select Subcommittee on Maritime Education and Training regarding the sea training of United States Merchant Marine officers. Examined are various approaches to meeting the sea training requirement, especially the options of maritime academy training vessels, sailing on U.S.-flag merchant…

Smart border: ad-hoc wireless sensor networks for border surveillance

NASA Astrophysics Data System (ADS)

He, Jun; Fallahi, Mahmoud; Norwood, Robert A.; Peyghambarian, Nasser

2011-06-01

Wireless sensor networks have been proposed as promising candidates to provide automated monitoring, target tracking, and intrusion detection for border surveillance. In this paper, we demonstrate an ad-hoc wireless sensor network system for border surveillance. The network consists of heterogeneously autonomous sensor nodes that distributively cooperate with each other to enable a smart border in remote areas. This paper also presents energy-aware and sleeping algorithms designed to maximize the operating lifetime of the deployed sensor network. Lessons learned in building the network and important findings from field experiments are shared in the paper.

Stochastic does not equal ad hoc. [theories of lunar origin

NASA Technical Reports Server (NTRS)

Hartmann, W. K.

1984-01-01

Some classes of influential events in solar system history are class-predictable but not event-predictable. Theories of lunar origin should not ignore class-predictable stochastic events. Impacts and close encounters with large objects during planet formation are class-predictable. These stochastic events, such as large impacts that triggered ejection of Earth-mantle material into a circum-Earth cloud, should not be rejected as ad hoc. A way to deal with such events scientifically is to investigate their consequences; if it can be shown that they might produce the Moon, they become viable concepts in theories of lunar origin.

Organization model for Mobile Wireless Sensor Networks inspired in Artificial Bee Colony

NASA Astrophysics Data System (ADS)

Freire Roberto, Guilherme; Castilho Maschi, Luis Fernando; Pigatto, Daniel Fernando; Jaquie Castelo Branco, Kalinka Regina Lucas; Alves Neves, Leandro; Montez, Carlos; Sandro Roschildt Pinto, Alex

2015-01-01

The purpose of this study is to find a self-organizing model for MWSN based on bee colonies in order to reduce the number of messages transmitted among nodes, and thus reduce the overall consumption energy while maintaining the efficiency of message delivery. The results obtained in this article are originated from simulations carried out with SINALGO software, which demonstrates the effectiveness of the proposed approach. The BeeAODV (Bee Ad-Hoc On Demand Distance Vector) proposed in this paper allows to considerably reduce message exchanges whether compared to AODV (Ad-Hoc On Demand Distance Vector).

A Secure and Privacy-Preserving Navigation Scheme Using Spatial Crowdsourcing in Fog-Based VANETs

PubMed Central

Wang, Lingling; Liu, Guozhu; Sun, Lijun

2017-01-01

Fog-based VANETs (Vehicular ad hoc networks) is a new paradigm of vehicular ad hoc networks with the advantages of both vehicular cloud and fog computing. Real-time navigation schemes based on fog-based VANETs can promote the scheme performance efficiently. In this paper, we propose a secure and privacy-preserving navigation scheme by using vehicular spatial crowdsourcing based on fog-based VANETs. Fog nodes are used to generate and release the crowdsourcing tasks, and cooperatively find the optimal route according to the real-time traffic information collected by vehicles in their coverage areas. Meanwhile, the vehicle performing the crowdsourcing task can get a reasonable reward. The querying vehicle can retrieve the navigation results from each fog node successively when entering its coverage area, and follow the optimal route to the next fog node until it reaches the desired destination. Our scheme fulfills the security and privacy requirements of authentication, confidentiality and conditional privacy preservation. Some cryptographic primitives, including the Elgamal encryption algorithm, AES, randomized anonymous credentials and group signatures, are adopted to achieve this goal. Finally, we analyze the security and the efficiency of the proposed scheme. PMID:28338620

A Secure and Privacy-Preserving Navigation Scheme Using Spatial Crowdsourcing in Fog-Based VANETs.

PubMed

Wang, Lingling; Liu, Guozhu; Sun, Lijun

2017-03-24

Fog-based VANETs (Vehicular ad hoc networks) is a new paradigm of vehicular ad hoc networks with the advantages of both vehicular cloud and fog computing. Real-time navigation schemes based on fog-based VANETs can promote the scheme performance efficiently. In this paper, we propose a secure and privacy-preserving navigation scheme by using vehicular spatial crowdsourcing based on fog-based VANETs. Fog nodes are used to generate and release the crowdsourcing tasks, and cooperatively find the optimal route according to the real-time traffic information collected by vehicles in their coverage areas. Meanwhile, the vehicle performing the crowdsourcing task can get a reasonable reward. The querying vehicle can retrieve the navigation results from each fog node successively when entering its coverage area, and follow the optimal route to the next fog node until it reaches the desired destination. Our scheme fulfills the security and privacy requirements of authentication, confidentiality and conditional privacy preservation. Some cryptographic primitives, including the Elgamal encryption algorithm, AES, randomized anonymous credentials and group signatures, are adopted to achieve this goal. Finally, we analyze the security and the efficiency of the proposed scheme.

a 3d Information System for the Documentation of Archaeologica L Excavations

NASA Astrophysics Data System (ADS)

Ardissone, P.; Bornaz, L.; Degattis, G.; Domaine, R.

2013-07-01

Documentation of archaeological and cultural heritage sites is at the heart of the archaeological process and an important component in cultural heritage research, presentation and restorations. In 2012 the Superintendence of Cultural Heritage of Aosta Valley - IT (Soprintendenza per i Beni e le Attività Culturali della Region e Autonoma Valle d'Aosta) carried out a complex archaeological excavation in a composite archaeological context, situated an urban background: the Aosta city centre. This archaeological excavation has been characterized by the classical urban archaeological issues: little space, short time, complex stratigraphy. Moreover the investigations have come out several structures and walls that required safety and conservation measures. Ad hoc 3D solutions carried out a complete 3D survey of the area in 10 different time/situations of the Archaeological digs, chosen in collaborations with the archaeological staff. In this way a multi temporal 3D description of the site has been provided for the archaeological analysis and for the project of the restorations activities. The 3D surveys has been carried out integrating GPS, laser scanner technology and photogrammetry. In order to meet the needs of the site, and its complex logistics and to obtain products that guarantee the high quality and detail required for archaeological analysis, we have developed different procedures and methodologies: hdr imaging for 3D model with correct, consistent and uniform colours, noise filtering and people filtering, for the removal of interference between laser instrument and object of the survey, Advanced laser scanner triangulation, in order to consider both artificial and natural tie points, for a correct registration of a huge amount of scans. Single image orientation on 3D data, in order to integrate the laser data with data coming from digital photogrammetry (faster on the field than the laser scanner survey, than used in certain situations). The results of all these methodologies and procedures will be presented and described in the article. For the documentation of the archaeological excavations and for the management of the conservation activities (condition assessment, planning, and conservation work). Ad Hoc 3D solutions has costumized 2 special plug-ins of its own software platform Ad Hoc: Ad Hoc Archaeology and Ad Hoc Conservation. The software platform integrates a 3D database management system. All information (measurements, plotting, areas of interests…) are organized according to their correct 3D position. They can be queried using attributes, geometric characteristics or their spatial position. The Ad Hoc Archaeology plug-in allows archeologists to fill out UUSS sheets in an internal database, put them in the correct location within the 3D model of the site, define the mutual relations between the UUSS, divide the different archaeological phases. A simple interface will facilitate the construction of the stratigraphic chart (matrix), in a 3D environment as well (matrix 3D). The Ad Hoc Conservation plug-in permits conservators and restorers to create relationships between the different approaches and descriptions of the same parts of the monument, i.e.: between stratigraphyc units or historical phases and architectural components and/or decay pathologies. The 3D DBMS conservation module uses a codified terminology based on "ICOMOS illustrated glossary of stone deterioration" and other glossary. Specific tools permits restorers to compute correctly surfaces and volumes. In this way decay extension and intensity can be measured with high precision and with an high level of detail, for a correct time and costs estimation of each conservation step.

Achieving sink node anonymity in tactical wireless sensor networks using a reactive routing protocol

DTIC Science & Technology

2017-06-01

transmit their information through the network based on the specific protocols that are implemented. Nodes may be designed to perform any combination of...band, and one channel in the 868-MHz band. The IEEE 802.15.4 standard is designed to provide Low-Rate Wireless Personal Area Network (LR-WPAN...MANETs and is currently a draft at the IETF Network Working Group [9]. It was derived from the Ad hoc On -Demand Distance Vector (AODV) routing

Classification Management. Journal of the National Classification Management Society, Volume 18, 1982,

DTIC Science & Technology

1983-01-01

changes. Concurrently, CIA formed and AD HOC esting to step back and look at the U.S. security Intelligence Community Working Group to re...administrative error; to prevent embarrassment to expected damage will be. If you foresee the dam- a person, organization, or agency; to restrain com- age...the decision will be to classify the informa- petition; or to pTevent or delay the public release of tion. But note that in this thought process, you

Dynamic fair node spectrum allocation for ad hoc networks using random matrices

NASA Astrophysics Data System (ADS)

Rahmes, Mark; Lemieux, George; Chester, Dave; Sonnenberg, Jerry

2015-05-01

Dynamic Spectrum Access (DSA) is widely seen as a solution to the problem of limited spectrum, because of its ability to adapt the operating frequency of a radio. Mobile Ad Hoc Networks (MANETs) can extend high-capacity mobile communications over large areas where fixed and tethered-mobile systems are not available. In one use case with high potential impact, cognitive radio employs spectrum sensing to facilitate the identification of allocated frequencies not currently accessed by their primary users. Primary users own the rights to radiate at a specific frequency and geographic location, while secondary users opportunistically attempt to radiate at a specific frequency when the primary user is not using it. We populate a spatial radio environment map (REM) database with known information that can be leveraged in an ad hoc network to facilitate fair path use of the DSA-discovered links. Utilization of high-resolution geospatial data layers in RF propagation analysis is directly applicable. Random matrix theory (RMT) is useful in simulating network layer usage in nodes by a Wishart adjacency matrix. We use the Dijkstra algorithm for discovering ad hoc network node connection patterns. We present a method for analysts to dynamically allocate node-node path and link resources using fair division. User allocation of limited resources as a function of time must be dynamic and based on system fairness policies. The context of fair means that first available request for an asset is not envied as long as it is not yet allocated or tasked in order to prevent cycling of the system. This solution may also save money by offering a Pareto efficient repeatable process. We use a water fill queue algorithm to include Shapley value marginal contributions for allocation.

Management of Energy Consumption on Cluster Based Routing Protocol for MANET

NASA Astrophysics Data System (ADS)

Hosseini-Seno, Seyed-Amin; Wan, Tat-Chee; Budiarto, Rahmat; Yamada, Masashi

The usage of light-weight mobile devices is increasing rapidly, leading to demand for more telecommunication services. Consequently, mobile ad hoc networks and their applications have become feasible with the proliferation of light-weight mobile devices. Many protocols have been developed to handle service discovery and routing in ad hoc networks. However, the majority of them did not consider one critical aspect of this type of network, which is the limited of available energy in each node. Cluster Based Routing Protocol (CBRP) is a robust/scalable routing protocol for Mobile Ad hoc Networks (MANETs) and superior to existing protocols such as Ad hoc On-demand Distance Vector (AODV) in terms of throughput and overhead. Therefore, based on this strength, methods to increase the efficiency of energy usage are incorporated into CBRP in this work. In order to increase the stability (in term of life-time) of the network and to decrease the energy consumption of inter-cluster gateway nodes, an Enhanced Gateway Cluster Based Routing Protocol (EGCBRP) is proposed. Three methods have been introduced by EGCBRP as enhancements to the CBRP: improving the election of cluster Heads (CHs) in CBRP which is based on the maximum available energy level, implementing load balancing for inter-cluster traffic using multiple gateways, and implementing sleep state for gateway nodes to further save the energy. Furthermore, we propose an Energy Efficient Cluster Based Routing Protocol (EECBRP) which extends the EGCBRP sleep state concept into all idle member nodes, excluding the active nodes in all clusters. The experiment results show that the EGCBRP decreases the overall energy consumption of the gateway nodes up to 10% and the EECBRP reduces the energy consumption of the member nodes up to 60%, both of which in turn contribute to stabilizing the network.

T2AR: trust-aware ad-hoc routing protocol for MANET.

PubMed

Dhananjayan, Gayathri; Subbiah, Janakiraman

2016-01-01

Secure data transfer against the malicious attacks is an important issue in an infrastructure-less independent network called mobile ad-hoc network (MANET). Trust assurance between MANET nodes is the key parameter in the high-security provision under dynamic topology variations and open wireless constraints. But, the malicious behavior of nodes reduces the trust level of the nodes that leads to an insecure data delivery. The increase in malicious attacks causes the excessive energy consumption that leads to a reduction of network lifetime. The lack of positional information update of the nodes in ad-hoc on-demand vector (AODV) protocol during the connection establishment offers less trust level between the nodes. Hence, the trust rate computation using energy and mobility models and its update are the essential tasks for secure data delivery. This paper proposes a trust-aware ad-hoc routing (T2AR) protocol to improve the trust level between the nodes in MANET. The proposed method modifies the traditional AODV routing protocol with the constraints of trust rate, energy, mobility based malicious behavior prediction. The packet sequence ID matching from the log reports of neighbor nodes determine the trust rate that avoids the malicious report generation. Besides, the direct and indirect trust observation schemes utilization increases the trust level. Besides, the received signal strength indicator utilization determines the trusted node is within the communication range or not. The comparative analysis between the proposed T2AR with the existing methods such as TRUNCMAN, RBT, GR, FBR and DICOTIDS regarding the average end-to-end delay, throughput, false positives, packet delivery ratio shows the effectiveness of T2AR in the secure MANET environment design.

FRED: Exergame to Prevent Dependence and Functional Deterioration Associated with Ageing. A Pilot Three-Week Randomized Controlled Clinical Trial.

PubMed

Mugueta-Aguinaga, Iranzu; Garcia-Zapirain, Begonya

2017-11-23

Introduction: Frailty syndrome and advanced age may decrease the acceptance of illness and quality of life, and worsen patients' existing health conditions, as well as leading to an increase in health care expenses. Purpose: The purpose of this study is to reduce frailty risk via the use of a FRED game which has been expressly designed and put together for the study. Materials and methods: A total of 40 frail volunteers with a score of <10 points in the short physical performance battery (SPPB) took part in a feasibility study in order to validate the FRED game. Following randomisation, the study group (20 subjects) took part in nine sessions of 20 min each over a three-week period. The control group (19 subjects) continued to lead their daily lives in the course of which they had no physical activity scheduled; Results: After three weeks and having taken part in nine physical activity sessions with the FRED game, 60% of subjects from the study group (12/20) obtained a score of ≥10 points at the end of the study, i.e., less risk of evidencing frailty. This result proved to be statistically significant ( p < 0.001). The degree of compliance with and adherence to the game was confirmed by 100% attendance of the sessions. Discussion: Our findings support the hypothesis that FRED, an ad hoc designed exergame, significantly reduced the presence and severity of frailty in a sample of sedentary elders, thus potentially modifying their risk profile. Conclusions: The FRED game is a tool that shows a 99% certain improvement in the degree of frailty in frail elderly subjects. The effectiveness of the design of ad hoc games in a certain pathology or population group is therefore evidenced.

FRED: Exergame to Prevent Dependence and Functional Deterioration Associated with Ageing. A Pilot Three-Week Randomized Controlled Clinical Trial

PubMed Central

Garcia-Zapirain, Begonya

2017-01-01

Introduction: Frailty syndrome and advanced age may decrease the acceptance of illness and quality of life, and worsen patients’ existing health conditions, as well as leading to an increase in health care expenses. Purpose: The purpose of this study is to reduce frailty risk via the use of a FRED game which has been expressly designed and put together for the study. Materials and Methods: A total of 40 frail volunteers with a score of <10 points in the short physical performance battery (SPPB) took part in a feasibility study in order to validate the FRED game. Following randomisation, the study group (20 subjects) took part in nine sessions of 20 min each over a three-week period. The control group (19 subjects) continued to lead their daily lives in the course of which they had no physical activity scheduled; Results: After three weeks and having taken part in nine physical activity sessions with the FRED game, 60% of subjects from the study group (12/20) obtained a score of ≥10 points at the end of the study, i.e., less risk of evidencing frailty. This result proved to be statistically significant (p < 0.001). The degree of compliance with and adherence to the game was confirmed by 100% attendance of the sessions. Discussion: Our findings support the hypothesis that FRED, an ad hoc designed exergame, significantly reduced the presence and severity of frailty in a sample of sedentary elders, thus potentially modifying their risk profile. Conclusions: The FRED game is a tool that shows a 99% certain improvement in the degree of frailty in frail elderly subjects. The effectiveness of the design of ad hoc games in a certain pathology or population group is therefore evidenced. PMID:29168787

Harmonised investigation of the occurrence of human enteric viruses in the leafy green vegetable supply chain in three European countries.

PubMed

Kokkinos, P; Kozyra, I; Lazic, S; Bouwknegt, M; Rutjes, S; Willems, K; Moloney, R; de Roda Husman, A M; Kaupke, A; Legaki, E; D'Agostino, M; Cook, N; Rzeżutka, A; Petrovic, T; Vantarakis, A

2012-12-01

Numerous outbreaks have been attributed to the consumption of raw or minimally processed leafy green vegetables contaminated with enteric viral pathogens. The aim of the present study was an integrated virological monitoring of the salad vegetables supply chain in Europe, from production, processing and point-of-sale. Samples were collected and analysed in Greece, Serbia and Poland, from 'general' and 'ad hoc' sampling points, which were perceived as critical points for virus contamination. General sampling points were identified through the analysis of background information questionnaires based on HACCP audit principles, and they were sampled during each sampling occasion where as-ad hoc sampling points were identified during food safety fact-finding visits and samples were only collected during the fact-finding visits. Human (hAdV) and porcine (pAdV) adenovirus, hepatitis A (HAV) and E (HEV) virus, norovirus GI and GII (NoV) and bovine polyomavirus (bPyV) were detected by means of real-time (RT-) PCR-based protocols. General samples were positive for hAdV, pAdV, HAV, HEV, NoV GI, NoV GII and bPyV at 20.09 % (134/667), 5.53 % (13/235), 1.32 % (4/304), 3.42 % (5/146), 2 % (6/299), 2.95 % (8/271) and 0.82 % (2/245), respectively. Ad hoc samples were positive for hAdV, pAdV, bPyV and NoV GI at 9 % (3/33), 9 % (2/22), 4.54 % (1/22) and 7.14 % (1/14), respectively. These results demonstrate the existence of viral contamination routes from human and animal sources to the salad vegetable supply chain and more specifically indicate the potential for public health risks due to the virus contamination of leafy green vegetables at primary production.

Optimal JPWL Forward Error Correction Rate Allocation for Robust JPEG 2000 Images and Video Streaming over Mobile Ad Hoc Networks

NASA Astrophysics Data System (ADS)

Agueh, Max; Diouris, Jean-François; Diop, Magaye; Devaux, François-Olivier; De Vleeschouwer, Christophe; Macq, Benoit

2008-12-01

Based on the analysis of real mobile ad hoc network (MANET) traces, we derive in this paper an optimal wireless JPEG 2000 compliant forward error correction (FEC) rate allocation scheme for a robust streaming of images and videos over MANET. The packet-based proposed scheme has a low complexity and is compliant to JPWL, the 11th part of the JPEG 2000 standard. The effectiveness of the proposed method is evaluated using a wireless Motion JPEG 2000 client/server application; and the ability of the optimal scheme to guarantee quality of service (QoS) to wireless clients is demonstrated.

Scalable Architecture for Multihop Wireless ad Hoc Networks

NASA Technical Reports Server (NTRS)

Arabshahi, Payman; Gray, Andrew; Okino, Clayton; Yan, Tsun-Yee

2004-01-01

A scalable architecture for wireless digital data and voice communications via ad hoc networks has been proposed. Although the details of the architecture and of its implementation in hardware and software have yet to be developed, the broad outlines of the architecture are fairly clear: This architecture departs from current commercial wireless communication architectures, which are characterized by low effective bandwidth per user and are not well suited to low-cost, rapid scaling in large metropolitan areas. This architecture is inspired by a vision more akin to that of more than two dozen noncommercial community wireless networking organizations established by volunteers in North America and several European countries.

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.

A secure 3-way routing protocols for intermittently connected mobile ad hoc networks.

PubMed

Sekaran, Ramesh; Parasuraman, Ganesh Kumar

2014-01-01

The mobile ad hoc network may be partially connected or it may be disconnected in nature and these forms of networks are termed intermittently connected mobile ad hoc network (ICMANET). The routing in such disconnected network is commonly an arduous task. Many routing protocols have been proposed for routing in ICMANET since decades. The routing techniques in existence for ICMANET are, namely, flooding, epidemic, probabilistic, copy case, spray and wait, and so forth. These techniques achieve an effective routing with minimum latency, higher delivery ratio, lesser overhead, and so forth. Though these techniques generate effective results, in this paper, we propose novel routing algorithms grounded on agent and cryptographic techniques, namely, location dissemination service (LoDiS) routing with agent AES, A-LoDiS with agent AES routing, and B-LoDiS with agent AES routing, ensuring optimal results with respect to various network routing parameters. The algorithm along with efficient routing ensures higher degree of security. The security level is cited testing with respect to possibility of malicious nodes into the network. This paper also aids, with the comparative results of proposed algorithms, for secure routing in ICMANET.

A Secure 3-Way Routing Protocols for Intermittently Connected Mobile Ad Hoc Networks

PubMed Central

Parasuraman, Ganesh Kumar

2014-01-01

The mobile ad hoc network may be partially connected or it may be disconnected in nature and these forms of networks are termed intermittently connected mobile ad hoc network (ICMANET). The routing in such disconnected network is commonly an arduous task. Many routing protocols have been proposed for routing in ICMANET since decades. The routing techniques in existence for ICMANET are, namely, flooding, epidemic, probabilistic, copy case, spray and wait, and so forth. These techniques achieve an effective routing with minimum latency, higher delivery ratio, lesser overhead, and so forth. Though these techniques generate effective results, in this paper, we propose novel routing algorithms grounded on agent and cryptographic techniques, namely, location dissemination service (LoDiS) routing with agent AES, A-LoDiS with agent AES routing, and B-LoDiS with agent AES routing, ensuring optimal results with respect to various network routing parameters. The algorithm along with efficient routing ensures higher degree of security. The security level is cited testing with respect to possibility of malicious nodes into the network. This paper also aids, with the comparative results of proposed algorithms, for secure routing in ICMANET. PMID:25136697

Energy Efficient Probabilistic Broadcasting for Mobile Ad-Hoc Network

NASA Astrophysics Data System (ADS)

Kumar, Sumit; Mehfuz, Shabana

2017-06-01

In mobile ad-hoc network (MANETs) flooding method is used for broadcasting route request (RREQ) packet from one node to another node for route discovery. This is the simplest method of broadcasting of RREQ packets but it often results in broadcast storm problem, originating collisions and congestion of packets in the network. A probabilistic broadcasting is one of the widely used broadcasting scheme for route discovery in MANETs and provides solution for broadcasting storm problem. But it does not consider limited energy of the battery of the nodes. In this paper, a new energy efficient probabilistic broadcasting (EEPB) is proposed in which probability of broadcasting RREQs is calculated with respect to remaining energy of nodes. The analysis of simulation results clearly indicate that an EEPB route discovery scheme in ad-hoc on demand distance vector (AODV) can increase the network lifetime with a decrease in the average power consumption and RREQ packet overhead. It also decreases the number of dropped packets in the network, in comparison to other EEPB schemes like energy constraint gossip (ECG), energy aware gossip (EAG), energy based gossip (EBG) and network lifetime through energy efficient broadcast gossip (NEBG).

DataSpread: Unifying Databases and Spreadsheets.

PubMed

Bendre, Mangesh; Sun, Bofan; Zhang, Ding; Zhou, Xinyan; Chang, Kevin ChenChuan; Parameswaran, Aditya

2015-08-01

Spreadsheet software is often the tool of choice for ad-hoc tabular data management, processing, and visualization, especially on tiny data sets. On the other hand, relational database systems offer significant power, expressivity, and efficiency over spreadsheet software for data management, while lacking in the ease of use and ad-hoc analysis capabilities. We demonstrate DataSpread, a data exploration tool that holistically unifies databases and spreadsheets. It continues to offer a Microsoft Excel-based spreadsheet front-end, while in parallel managing all the data in a back-end database, specifically, PostgreSQL. DataSpread retains all the advantages of spreadsheets, including ease of use, ad-hoc analysis and visualization capabilities, and a schema-free nature, while also adding the advantages of traditional relational databases, such as scalability and the ability to use arbitrary SQL to import, filter, or join external or internal tables and have the results appear in the spreadsheet. DataSpread needs to reason about and reconcile differences in the notions of schema, addressing of cells and tuples, and the current "pane" (which exists in spreadsheets but not in traditional databases), and support data modifications at both the front-end and the back-end. Our demonstration will center on our first and early prototype of the DataSpread, and will give the attendees a sense for the enormous data exploration capabilities offered by unifying spreadsheets and databases.

DataSpread: Unifying Databases and Spreadsheets

PubMed Central

Bendre, Mangesh; Sun, Bofan; Zhang, Ding; Zhou, Xinyan; Chang, Kevin ChenChuan; Parameswaran, Aditya

2015-01-01

Spreadsheet software is often the tool of choice for ad-hoc tabular data management, processing, and visualization, especially on tiny data sets. On the other hand, relational database systems offer significant power, expressivity, and efficiency over spreadsheet software for data management, while lacking in the ease of use and ad-hoc analysis capabilities. We demonstrate DataSpread, a data exploration tool that holistically unifies databases and spreadsheets. It continues to offer a Microsoft Excel-based spreadsheet front-end, while in parallel managing all the data in a back-end database, specifically, PostgreSQL. DataSpread retains all the advantages of spreadsheets, including ease of use, ad-hoc analysis and visualization capabilities, and a schema-free nature, while also adding the advantages of traditional relational databases, such as scalability and the ability to use arbitrary SQL to import, filter, or join external or internal tables and have the results appear in the spreadsheet. DataSpread needs to reason about and reconcile differences in the notions of schema, addressing of cells and tuples, and the current “pane” (which exists in spreadsheets but not in traditional databases), and support data modifications at both the front-end and the back-end. Our demonstration will center on our first and early prototype of the DataSpread, and will give the attendees a sense for the enormous data exploration capabilities offered by unifying spreadsheets and databases. PMID:26900487

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

Tang, J. Y.; Riley, W. J.

We present a generic flux limiter to account for mass limitations from an arbitrary number of substrates in a biogeochemical reaction network. The flux limiter is based on the observation that substrate (e.g., nitrogen, phosphorus) limitation in biogeochemical models can be represented as to ensure mass conservative and non-negative numerical solutions to the governing ordinary differential equations. Application of the flux limiter includes two steps: (1) formulation of the biogeochemical processes with a matrix of stoichiometric coefficients and (2) application of Liebig's law of the minimum using the dynamic stoichiometric relationship of the reactants. This approach contrasts with the ad hoc down-regulationmore » approaches that are implemented in many existing models (such as CLM4.5 and the ACME (Accelerated Climate Modeling for Energy) Land Model (ALM)) of carbon and nutrient interactions, which are error prone when adding new processes, even for experienced modelers. Through an example implementation with a CENTURY-like decomposition model that includes carbon, nitrogen, and phosphorus, we show that our approach (1) produced almost identical results to that from the ad hoc down-regulation approaches under non-limiting nutrient conditions, (2) properly resolved the negative solutions under substrate-limited conditions where the simple clipping approach failed, (3) successfully avoided the potential conceptual ambiguities that are implied by those ad hoc down-regulation approaches. We expect our approach will make future biogeochemical models easier to improve and more robust.« less

Sorption of Hydrophobic Organic Compounds on Natural Sorbents and Organoclays from Aqueous and Non-Aqueous Solutions: A Mini-Review

PubMed Central

Moyo, Francis; Tandlich, Roman; Wilhelmi, Brendan S.; Balaz, Stefan

2014-01-01

Renewed focus on the sorption of hydrophobic organic chemicals (HOCs) onto mineral surfaces and soil components is required due to the increased and wider range of organic pollutants being released into the environment. This mini-review examines the possibility of the contribution and mechanism of HOC sorption onto clay mineral sorbents such as kaolinite, and soil organic matter and the possible role of both in the prevention of environmental contamination by HOCs. Literature data indicates that certain siloxane surfaces can be hydrophobic. Therefore soils can retain HOCs even at low soil organic levels and the extent will depend on the structure of the pollutant and the type and concentration of clay minerals in the sorbent. Clay minerals are wettable by nonpolar solvents and so sorption of HOCs onto them from aqueous and non-aqueous solutions is possible. This is important for two reasons: firstly, the movement and remediation of soil environments will be a function of the concentration and type of clay minerals in the soil. Secondly, low-cost sorbents such as kaolinite and expandable clays can be added to soils or contaminated environments as temporary retention barriers for HOCs. Inorganic cations sorbed onto the kaolinite have a strong influence on the rate and extent of sorption of hydrophobic organic pollutants onto kaolinite. Structural sorbate classes that can be retained by the kaolinite matrix are limited by hydrogen bonding between hydroxyl groups of the octahedral alumosilicate sheet and the tetrahedral sheet with silicon. Soil organic carbon plays a key role in the sorption of HOCs onto soils, but the extent will be strongly affected by the structure of the organic soil matter and the presence of soot. Structural characterisation of soil organic matter in a particular soil should be conducted during a particular contamination event. Contamination by mining extractants and antibiotics will require renewed focus on the use of the QSAR approaches in the context of the sorption of HOCs onto clay minerals from aqueous and non-aqueous solutions. PMID:24821385

Long-term efficacy and safety of safinamide as add-on therapy in early Parkinson's disease.

PubMed

Schapira, A H V; Stocchi, F; Borgohain, R; Onofrj, M; Bhatt, M; Lorenzana, P; Lucini, V; Giuliani, R; Anand, R

2013-02-01

Safinamide is an α-aminoamide with both dopaminergic and non-dopaminergic mechanisms of action in Phase III clinical development as a once-daily add-on to dopamine agonist (DA) therapy for early Parkinson's disease (PD). Study 017 was a 12-month, randomized, double-blind, placebo-controlled pre-planned extension study to the previously reported Study 015. Patients received safinamide 100 or 200 mg/day or placebo added to a single DA in early PD. The primary efficacy endpoint was the time from baseline (Study 015 randomization) to 'intervention', defined as increase in DA dose; addition of another DA, levodopa or other PD treatment; or discontinuation due to lack of efficacy. Safinamide groups were pooled for the primary efficacy endpoint analysis; post hoc analyses were performed on each separate dose group. Of the 269 patients randomized in Study 015, 227 (84%) enrolled in Study 017 and 187/227 (82%) patients completed the extension study. Median time to intervention was 559 and 466 days in the pooled safinamide and placebo groups, respectively (log-rank test; P = 0.3342). In post hoc analyses, patients receiving safinamide 100 mg/day experienced a significantly lower rate of intervention compared with placebo (25% vs. 51%, respectively) and a delay in median time to intervention of 9 days (P < 0.05; 240- to 540-day analysis). The pooled data from the safinamide groups failed to reach statistical significance for the primary endpoint of median time from baseline to additional drug intervention. Post hoc analyses indicate that safinamide 100 mg/day may be effective as add-on treatment to DA in PD. © 2012 The Author(s) European Journal of Neurology © 2012 EFNS.

Do Professional Interpreters Improve Clinical Care for Patients with Limited English Proficiency? A Systematic Review of the Literature

PubMed Central

Karliner, Leah S; Jacobs, Elizabeth A; Chen, Alice Hm; Mutha, Sunita

2007-01-01

Objective To determine if professional medical interpreters have a positive impact on clinical care for limited English proficiency (LEP) patients. Data Sources A systematic literature search, limited to the English language, in PubMed and PsycINFO for publications between 1966 and September 2005, and a search of the Cochrane Library. Study Design Any peer-reviewed article which compared at least two language groups, and contained data about professional medical interpreters and addressed communication (errors and comprehension), utilization, clinical outcomes, or satisfaction were included. Of 3,698 references, 28 were found by multiple reviewers to meet inclusion criteria and, of these, 21 assessed professional interpreters separately from ad hoc interpreters. Data were abstracted from each article by two reviewers. Data were collected on the study design, size, comparison groups, analytic technique, interpreter training, and method of determining the participants' need for an interpreter. Each study was evaluated for the effect of interpreter use on four clinical topics that were most likely to either impact or reflect disparities in health and health care. Principal Findings In all four areas examined, use of professional interpreters is associated with improved clinical care more than is use of ad hoc interpreters, and professional interpreters appear to raise the quality of clinical care for LEP patients to approach or equal that for patients without language barriers. Conclusions Published studies report positive benefits of professional interpreters on communication (errors and comprehension), utilization, clinical outcomes and satisfaction with care. PMID:17362215

Categorial Compositionality III: F-(co)algebras and the Systematicity of Recursive Capacities in Human Cognition

PubMed Central

Phillips, Steven; Wilson, William H.

2012-01-01

Human cognitive capacity includes recursively definable concepts, which are prevalent in domains involving lists, numbers, and languages. Cognitive science currently lacks a satisfactory explanation for the systematic nature of such capacities (i.e., why the capacity for some recursive cognitive abilities–e.g., finding the smallest number in a list–implies the capacity for certain others–finding the largest number, given knowledge of number order). The category-theoretic constructs of initial F-algebra, catamorphism, and their duals, final coalgebra and anamorphism provide a formal, systematic treatment of recursion in computer science. Here, we use this formalism to explain the systematicity of recursive cognitive capacities without ad hoc assumptions (i.e., to the same explanatory standard used in our account of systematicity for non-recursive capacities). The presence of an initial algebra/final coalgebra explains systematicity because all recursive cognitive capacities, in the domain of interest, factor through (are composed of) the same component process. Moreover, this factorization is unique, hence no further (ad hoc) assumptions are required to establish the intrinsic connection between members of a group of systematically-related capacities. This formulation also provides a new perspective on the relationship between recursive cognitive capacities. In particular, the link between number and language does not depend on recursion, as such, but on the underlying functor on which the group of recursive capacities is based. Thus, many species (and infants) can employ recursive processes without having a full-blown capacity for number and language. PMID:22514704

Field dependence-independence as related to young women's participation in sports activity.

PubMed

Lambrecht, Jeanne L; Cuevas, Jacqueline L

2007-06-01

To estimate association between field dependence-independence measured by scores on the Group Embedded Figures Test and young women's participation in sports activity. Participants were 37 undergraduate college women between the ages of 18 and 25 years (M=21). Participants were categorized into two groups, one high in participation in sports activity and one low. A one-tailed independent samples t test yielded no significant difference. Correlations of .36 and .18 were significant but account for little common variance. An ad hoc analysis performed without participants who reported softball activity but who were highly involved in sport activities was significant.

Influence of Educational Attainment on Cognition-Based Intervention Programs for Persons with Mild Alzheimer's Disease.

PubMed

Contador, Israel; Fernández-Calvo, Bernardino; Ramos, Francisco; Olazarán, Javier

2016-05-01

This research retrospectively analyzed the effect of education on cognitive interventions carried out in patients with mild Alzheimer's disease (AD). The total sample consisted of 75 patients with mild AD receiving treatment with cholinesterase inhibitors. The participants were divided into two groups: cognitive intervention (IG; n=45) and waiting list (WLG; n=30). Patients in the IG received either the Big Brain Academy (n=15) or the Integrated Psychostimulation Program (n=30) during 12 weeks. The influence of education on intervention effect was analyzed comparing mean change scores of the two study groups in the cognitive subscale of the Alzheimer's Disease Assessment Scale (ADAS-cog), stratified by educational level. The potential effect of age, sex, cognitive status, and type of intervention was examined using post hoc stratification analyses. Higher education was associated with faster cognitive decline in the WLG (effect size=0.51; p<.01). However, cognitive evolution was not influenced by education in the IG (effect size=0.12; p=.42). Our results suggest that cognitive intervention might delay accelerated cognitive decline in higher educated individuals with mild AD.

Deep Brain Stimulation Targeting the Fornix for Mild Alzheimer Dementia (the ADvance Trial): A Two Year Follow-up Including Results of Delayed Activation.

PubMed

Leoutsakos, Jeannie-Marie S; Yan, Haijuan; Anderson, William S; Asaad, Wael F; Baltuch, Gordon; Burke, Anna; Chakravarty, M Mallar; Drake, Kristen E; Foote, Kelly D; Fosdick, Lisa; Giacobbe, Peter; Mari, Zoltan; McAndrews, Mary Pat; Munro, Cynthia A; Oh, Esther S; Okun, Michael S; Pendergrass, Jo Cara; Ponce, Francisco A; Rosenberg, Paul B; Sabbagh, Marwan N; Salloway, Stephen; Tang-Wai, David F; Targum, Steven D; Wolk, David; Lozano, Andres M; Smith, Gwenn S; Lyketsos, Constantine G

2018-06-09

Given recent challenges in developing new treatments for Alzheimer dementia (AD), it is vital to explore alternate treatment targets, such as neuromodulation for circuit dysfunction. We previously reported an exploratory Phase IIb double-blind trial of deep brain stimulation targeting the fornix (DBS-f) in mild AD (the ADvance trial). We reported safety but no clinical benefits of DBS-f versus the delayed-on (sham) treatment in 42 participants after one year. However, secondary post hoc analyses of the one-year data suggested a possible DBS-f benefit for participants≥65 years. To examine the long-term safety and clinical effects of sustained and delayed-on DBS-f treatment of mild AD after two years. 42 participants underwent implantation of DBS-f electrodes, with half randomized to active DBS-f stimulation (early on) for two years and half to delayed-on (sham) stimulation after 1 year to provide 1 year of active DBS-f stimulation (delayed on). We evaluated safety and clinical outcomes over the two years of the trial. DBS-f had a favorable safety profile with similar rates of adverse events across both trial phases (years 1 and 2) and between treatment arms. There were no differences between treatment arms on any primary clinical outcomes. However, post-hoc age group analyses suggested a possible benefit among older (>65) participants. DBS-f was safe. Additional study of mechanisms of action and methods for titrating stimulation parameters will be needed to determine if DBS has potential as an AD treatment. Future efficacy studies should focus on patients over age 65.

A memetic optimization algorithm for multi-constrained multicast routing in ad hoc networks

PubMed Central

Hammad, Karim; El Bakly, Ahmed M.

2018-01-01

A mobile ad hoc network is a conventional self-configuring network where the routing optimization problem—subject to various Quality-of-Service (QoS) constraints—represents a major challenge. Unlike previously proposed solutions, in this paper, we propose a memetic algorithm (MA) employing an adaptive mutation parameter, to solve the multicast routing problem with higher search ability and computational efficiency. The proposed algorithm utilizes an updated scheme, based on statistical analysis, to estimate the best values for all MA parameters and enhance MA performance. The numerical results show that the proposed MA improved the delay and jitter of the network, while reducing computational complexity as compared to existing algorithms. PMID:29509760

A memetic optimization algorithm for multi-constrained multicast routing in ad hoc networks.

PubMed

Ramadan, Rahab M; Gasser, Safa M; El-Mahallawy, Mohamed S; Hammad, Karim; El Bakly, Ahmed M

2018-01-01

A mobile ad hoc network is a conventional self-configuring network where the routing optimization problem-subject to various Quality-of-Service (QoS) constraints-represents a major challenge. Unlike previously proposed solutions, in this paper, we propose a memetic algorithm (MA) employing an adaptive mutation parameter, to solve the multicast routing problem with higher search ability and computational efficiency. The proposed algorithm utilizes an updated scheme, based on statistical analysis, to estimate the best values for all MA parameters and enhance MA performance. The numerical results show that the proposed MA improved the delay and jitter of the network, while reducing computational complexity as compared to existing algorithms.

Evolution of Geometric Sensitivity Derivatives from Computer Aided Design Models

NASA Technical Reports Server (NTRS)

Jones, William T.; Lazzara, David; Haimes, Robert

2010-01-01

The generation of design parameter sensitivity derivatives is required for gradient-based optimization. Such sensitivity derivatives are elusive at best when working with geometry defined within the solid modeling context of Computer-Aided Design (CAD) systems. Solid modeling CAD systems are often proprietary and always complex, thereby necessitating ad hoc procedures to infer parameter sensitivity. A new perspective is presented that makes direct use of the hierarchical associativity of CAD features to trace their evolution and thereby track design parameter sensitivity. In contrast to ad hoc methods, this method provides a more concise procedure following the model design intent and determining the sensitivity of CAD geometry directly to its respective defining parameters.

Ad Hoc Selection of Voice over Internet Streams

NASA Technical Reports Server (NTRS)

Macha, Mitchell G. (Inventor); Bullock, John T. (Inventor)

2014-01-01

A method and apparatus for a communication system technique involving ad hoc selection of at least two audio streams is provided. Each of the at least two audio streams is a packetized version of an audio source. A data connection exists between a server and a client where a transport protocol actively propagates the at least two audio streams from the server to the client. Furthermore, software instructions executable on the client indicate a presence of the at least two audio streams, allow selection of at least one of the at least two audio streams, and direct the selected at least one of the at least two audio streams for audio playback.

Ad Hoc Selection of Voice over Internet Streams

NASA Technical Reports Server (NTRS)

Macha, Mitchell G. (Inventor); Bullock, John T. (Inventor)

2008-01-01

A method and apparatus for a communication system technique involving ad hoc selection of at least two audio streams is provided. Each of the at least two audio streams is a packetized version of an audio source. A data connection exists between a server and a client where a transport protocol actively propagates the at least two audio streams from the server to the client. Furthermore, software instructions executable on the client indicate a presence of the at least two audio streams, allow selection of at least one of the at least two audio streams, and direct the selected at least one of the at least two audio streams for audio playback.

The effects of exercise on oxidative stress (TBARS) and BDNF in severely depressed inpatients.

PubMed

Schuch, Felipe Barreto; Vasconcelos-Moreno, Mirela Paiva; Borowsky, Carolina; Zimmermann, Ana Beatriz; Wollenhaupt-Aguiar, Bianca; Ferrari, Pamela; de Almeida Fleck, Marcelo Pio

2014-10-01

Exercise can be an effective treatment for depression. Although the efficacy of exercise is well established, little is known concerning the biological changes associated with the antidepressant effects of exercise. A randomized, controlled trial was conducted to evaluate the effects of adding exercise to the usual treatment on the thiobarbituric acid-reactive substances (TBARS) and brain-derived neurotrophic factor (BDNF) serum levels of severely depressed inpatients. Twenty-six participants were randomized to an exercise group (n=15, exercise+treatment as usual) or a control group (n=11, treatment as usual). The participants in the exercise group completed a targeted dose of 16.5 kcal/kg/week of aerobic exercise, three times per week, throughout their hospitalizations. The control group did not exercise during their hospitalizations. The mean hospitalization length was of 21.63 (4.5)×23.82 (5.7) days for exercise and control groups, respectively. The exercise group performed a median of nine sessions. After adjusting for previous tobacco use, a significant group×time interaction was found for TBARS serum levels (p=0.02). A post hoc Bonferroni test revealed differences between the exercise and control groups at discharge. A significant time effect (p<0.001) but no group×time interaction was found (p=0.13) for BDNF serum levels. Adding exercise to the usual treatment of severely depressed inpatients decreases the TBARS serum levels of severely depressed inpatients after 3 weeks. Adding exercise had no additional effects on BDNF serum levels.

Cost study of solar cell space power systems.

NASA Technical Reports Server (NTRS)

Bernatowicz, D. T.

1972-01-01

A study of historical costs for solar cell space power systems was made by a NASA ad hoc study group. The study covered thirteen missions that represented a broad cross-section of flight projects over the past decade. Fully burdened costs in terms of 1971 dollars are presented for the system and the solar array. The costs correlate reasonably well with array area and do not increase in proportion to array area. The trends for array costs support the contention that solar cell and module standardization would reduce costs.

Structural dynamics technology research in NASA: Perspective on future needs

NASA Technical Reports Server (NTRS)

1979-01-01

The perspective of a NASA ad hoc study group on future research needs in structural dynamics within the aerospace industry is presented. The common aspects of the design process across the industry are identified and the role of structural dynamics is established through a discussion of various design considerations having their basis in structural dynamics. The specific structural dynamics issues involved are identified and assessed as to their current technological status and trends. Projections of future requirements based on this assessment are made and areas of research to meet them are identified.

A framework for marketing image management.

PubMed

Barich, H; Kotler, P

1991-01-01

Managers know that the customer's impression of an organization is important. And sometimes companies attempt to determine just what that impression is. They conduct ad hoc surveys and focus groups. But too often the data is insubstantial, or difficult to analyze, or even inaccurate. Barich and Kotler introduce the concept of "marketing image" and describe a system of image management: designing a study, collecting data, analyzing image problems, modifying the image, and tracking responses to that image. They argue that only a systematic approach will yield useful and accurate information that a company can translate into action.

Energy conservation in ad hoc multimedia networks using traffic-shaping mechanisms

NASA Astrophysics Data System (ADS)

Chandra, Surendar

2003-12-01

In this work, we explore network traffic shaping mechanisms that deliver packets at pre-determined intervals; allowing the network interface to transition to a lower power consuming sleep state. We focus our efforts on commodity devices, IEEE 802.11b ad hoc mode and popular streaming formats. We argue that factors such as the lack of scheduling clock phase synchronization among the participants and scheduling delays introduced by back ground tasks affect the potential energy savings. Increasing the periodic transmission delays to transmit data infrequently can offset some of these effects at the expense of flooding the wireless channel for longer periods of time; potentially increasing the time to acquire the channel for non-multimedia traffic. Buffering mechanisms built into media browsers can mitigate the effects of these added delays from being mis-interpreted as network congestion. We show that practical implementations of such traffic shaping mechanisms can offer significant energy savings.

A Game Theory Based Solution for Security Challenges in CRNs

NASA Astrophysics Data System (ADS)

Poonam; Nagpal, Chander Kumar

2018-03-01

Cognitive radio networks (CRNs) are being envisioned to drive the next generation Ad hoc wireless networks due to their ability to provide communications resilience in continuously changing environments through the use of dynamic spectrum access. Conventionally CRNs are dependent upon the information gathered by other secondary users to ensure the accuracy of spectrum sensing making them vulnerable to security attacks leading to the need of security mechanisms like cryptography and trust. However, a typical cryptography based solution is not a viable security solution for CRNs owing to their limited resources. Effectiveness of trust based approaches has always been, in question, due to credibility of secondary trust resources. Game theory with its ability to optimize in an environment of conflicting interests can be quite a suitable tool to manage an ad hoc network in the presence of autonomous selfish/malevolent/malicious and attacker nodes. The literature contains several theoretical proposals for augmenting game theory in the ad hoc networks without explicit/detailed implementation. This paper implements a game theory based solution in MATLAB-2015 to secure the CRN environment and compares the obtained results with the traditional approaches of trust and cryptography. The simulation result indicates that as the time progresses the game theory performs much better with higher throughput, lower jitter and better identification of selfish/malicious nodes.

Provision of out-of-hours interventional radiology services in the London strategic health authority.

PubMed

Illing, R O; Clark, C L Ingham; Allum, C

2010-04-01

To review the provision of out-of-hours interventional radiology (IR) services in the London Strategic Health Authority (SHA). All 29 acute hospitals in the London SHA were contacted between November 2008 and January 2009. A questionnaire based on the Royal College of Radiologists (RCR) guidelines assessed the provision of out-of-hours IR services. An "ad-hoc" service was defined as on-call provision where not all the radiologists could perform intervention: If IR was required out of hours, an interventionalist came in when off-duty or the patient was transferred. Seventeen out of the 29 (59%) hospitals provided ad-hoc out-of-hours services, eight (28%) provided a 24-hour rota, and four (14%) provide no out-of-hours cover. No ad-hoc service had formal transfer arrangements to a centre providing a 24h service. Only two hospitals providing a 24h service had six radiologists on the rota. Strategic planning for out-of-hours IR across London is recommended. This is likely to be welcomed by the hospitals involved, allowing informal arrangements to be formalized, and collaboration to provide comprehensive regional networks, provided appropriate funding is made available. A national audit is recommended; it is unlikely these findings are unique to London.

BCDP: Budget Constrained and Delay-Bounded Placement for Hybrid Roadside Units in Vehicular Ad Hoc Networks

PubMed Central

Li, Peng; Huang, Chuanhe; Liu, Qin

2014-01-01

In vehicular ad hoc networks, roadside units (RSUs) placement has been proposed to improve the the overall network performance in many ITS applications. This paper addresses the budget constrained and delay-bounded placement problem (BCDP) for roadside units in vehicular ad hoc networks. There are two types of RSUs: cable connected RSU (c-RSU) and wireless RSU (w-RSU). c-RSUs are interconnected through wired lines, and they form the backbone of VANETs, while w-RSUs connect to other RSUs through wireless communication and serve as an economical extension of the coverage of c-RSUs. The delay-bounded coverage range and deployment cost of these two cases are totally different. We are given a budget constraint and a delay bound, the problem is how to find the optimal candidate sites with the maximal delay-bounded coverage to place RSUs such that a message from any c-RSU in the region can be disseminated to the more vehicles within the given budget constraint and delay bound. We first prove that the BCDP problem is NP-hard. Then we propose several algorithms to solve the BCDP problem. Simulation results show the heuristic algorithms can significantly improve the coverage range and reduce the total deployment cost, compared with other heuristic methods. PMID:25436656

Reliable Geographical Forwarding in Cognitive Radio Sensor Networks Using Virtual Clusters

PubMed Central

Zubair, Suleiman; Fisal, Norsheila

2014-01-01

The need for implementing reliable data transfer in resource-constrained cognitive radio ad hoc networks is still an open issue in the research community. Although geographical forwarding schemes are characterized by their low overhead and efficiency in reliable data transfer in traditional wireless sensor network, this potential is still yet to be utilized for viable routing options in resource-constrained cognitive radio ad hoc networks in the presence of lossy links. In this paper, a novel geographical forwarding technique that does not restrict the choice of the next hop to the nodes in the selected route is presented. This is achieved by the creation of virtual clusters based on spectrum correlation from which the next hop choice is made based on link quality. The design maximizes the use of idle listening and receiver contention prioritization for energy efficiency, the avoidance of routing hot spots and stability. The validation result, which closely follows the simulation result, shows that the developed scheme can make more advancement to the sink as against the usual decisions of relevant ad hoc on-demand distance vector route select operations, while ensuring channel quality. Further simulation results have shown the enhanced reliability, lower latency and energy efficiency of the presented scheme. PMID:24854362

Energy-Aware Multipath Routing Scheme Based on Particle Swarm Optimization in Mobile Ad Hoc Networks

PubMed Central

Robinson, Y. Harold; Rajaram, M.

2015-01-01

Mobile ad hoc network (MANET) is a collection of autonomous mobile nodes forming an ad hoc network without fixed infrastructure. Dynamic topology property of MANET may degrade the performance of the network. However, multipath selection is a great challenging task to improve the network lifetime. We proposed an energy-aware multipath routing scheme based on particle swarm optimization (EMPSO) that uses continuous time recurrent neural network (CTRNN) to solve optimization problems. CTRNN finds the optimal loop-free paths to solve link disjoint paths in a MANET. The CTRNN is used as an optimum path selection technique that produces a set of optimal paths between source and destination. In CTRNN, particle swarm optimization (PSO) method is primly used for training the RNN. The proposed scheme uses the reliability measures such as transmission cost, energy factor, and the optimal traffic ratio between source and destination to increase routing performance. In this scheme, optimal loop-free paths can be found using PSO to seek better link quality nodes in route discovery phase. PSO optimizes a problem by iteratively trying to get a better solution with regard to a measure of quality. The proposed scheme discovers multiple loop-free paths by using PSO technique. PMID:26819966

Designing integrated computational biology pipelines visually.

PubMed

Jamil, Hasan M

2013-01-01

The long-term cost of developing and maintaining a computational pipeline that depends upon data integration and sophisticated workflow logic is too high to even contemplate "what if" or ad hoc type queries. In this paper, we introduce a novel application building interface for computational biology research, called VizBuilder, by leveraging a recent query language called BioFlow for life sciences databases. Using VizBuilder, it is now possible to develop ad hoc complex computational biology applications at throw away costs. The underlying query language supports data integration and workflow construction almost transparently and fully automatically, using a best effort approach. Users express their application by drawing it with VizBuilder icons and connecting them in a meaningful way. Completed applications are compiled and translated as BioFlow queries for execution by the data management system LifeDB, for which VizBuilder serves as a front end. We discuss VizBuilder features and functionalities in the context of a real life application after we briefly introduce BioFlow. The architecture and design principles of VizBuilder are also discussed. Finally, we outline future extensions of VizBuilder. To our knowledge, VizBuilder is a unique system that allows visually designing computational biology pipelines involving distributed and heterogeneous resources in an ad hoc manner.

Assessment of interbreeding and introgression of farm genes into a small Scottish Atlantic salmon Salmo salar stock: ad hoc samples - ad hoc results?

PubMed

Verspoor, E; Knox, D; Marshall, S

2016-12-01

An eclectic set of tissues and existing data, including purposely collected samples, spanning 1997-2006, was used in an ad hoc assessment of hybridization and introgression of farmed wild Atlantic salmon Salmo salar in the small Loch na Thull (LnT) catchment in north-west Scotland. The catchment is in an area of marine farm production and contains freshwater smolt rearing cages. The LnT S. salar stock was found to be genetically distinctive from stocks in neighbouring rivers and, despite regular reports of feral farm S. salar, there was no evidence of physical or genetic mixing. This cannot be completely ruled out, however, and low level mixing with other local wild stocks has been suggested. The LnT population appeared underpinned by relatively smaller effective number of breeders (N eb ) and showed relatively low levels of genetic diversity, consistent with a small effective population size. Small sample sizes, an incomplete farm baseline and the use of non-diagnostic molecular markers, constrain the power of the analysis but the findings strongly support the LnT catchment having a genetically distinct wild S. salar population little affected by interbreeding with feral farm escapes. © 2016 The Fisheries Society of the British Isles.

Technical Note: A generic law-of-the-minimum flux limiter for simulating substrate limitation in biogeochemical models

DOE PAGES

Tang, J. Y.; Riley, W. J.

2016-02-05

We present a generic flux limiter to account for mass limitations from an arbitrary number of substrates in a biogeochemical reaction network. The flux limiter is based on the observation that substrate (e.g., nitrogen, phosphorus) limitation in biogeochemical models can be represented as to ensure mass conservative and non-negative numerical solutions to the governing ordinary differential equations. Application of the flux limiter includes two steps: (1) formulation of the biogeochemical processes with a matrix of stoichiometric coefficients and (2) application of Liebig's law of the minimum using the dynamic stoichiometric relationship of the reactants. This approach contrasts with the ad hoc down-regulationmore » approaches that are implemented in many existing models (such as CLM4.5 and the ACME (Accelerated Climate Modeling for Energy) Land Model (ALM)) of carbon and nutrient interactions, which are error prone when adding new processes, even for experienced modelers. Through an example implementation with a CENTURY-like decomposition model that includes carbon, nitrogen, and phosphorus, we show that our approach (1) produced almost identical results to that from the ad hoc down-regulation approaches under non-limiting nutrient conditions, (2) properly resolved the negative solutions under substrate-limited conditions where the simple clipping approach failed, (3) successfully avoided the potential conceptual ambiguities that are implied by those ad hoc down-regulation approaches. We expect our approach will make future biogeochemical models easier to improve and more robust.« less

Volcanic influences: International working group on volcanogenic sediments

NASA Astrophysics Data System (ADS)

A conclusion of the Geological Society of America Penrose Conference on Volcanic Influences on Terrestrial Sedimentation (August 28 to September 2, 1988) was that establishment of an informal working group would enhance our understanding of volcanogenic sedimentation. To establish the group, an ad hoc steering committee was formed at the conference and consists of W. J. Fritz (Georgia State University), R. S. Hildebrand (Geological Survey of Canada), R. Iverson (U.S. Geological Survey), P. Kokelaar (Chairman, University of Liverpool), T. C. Pierson (USGS), and G. A. Smith (University of New Mexico). The working group is open to researchers of any nation interested in the study of secondary transport and deposition of volcaniclastic materials in subaerial or subaqueous environments (e.g., transport, deposition, nomenclature, volcanic history, experiment, theory, hazard).

The relationship between back pain and schoolbag use: a cross-sectional study of 5,318 Italian students.

PubMed

Aprile, Irene; Di Stasio, Enrico; Vincenzi, Maria Teresa; Arezzo, Maria Felice; De Santis, Fabio; Mosca, Rita; Briani, Chiara; Di Sipio, Enrica; Germanotta, Marco; Padua, Luca

2016-06-01

Back pain at a young age is considered to be predictive of chronicity. Several studies have investigated the relationship between the use of a schoolbag and back pain, although some aspects are still unclear. The aim of this study was to evaluate back pain due to schoolbag use in terms of (1) prevalence and intensity, (2) differences between male and female pupils, and (3) predisposing factors. This is a cross-sectional study. The sample was composed of 5,318 healthy pupils aged 6 to 19 years (classified according to three age groups: children, younger adolescents, and older adolescents). Schoolbag-related pain was assessed by means of an ad hoc questionnaire. The intensity of pain was assessed using the Wong scale. Subjects underwent a face-to-face interview using an ad hoc questionnaire. The intensity of pain was assessed using the Wong scale. On the basis of the prevalence and intensity of back pain, we divided our population into two groups: (1) no or mild pain group and (2) moderate or severe pain group. The "schoolbag load" (ratio between schoolbag and pupil weight multiplied by 100) was calculated for each subject. More than 60% of the subjects reported pain. Although the schoolbag load decreased from children to young and older adolescents, schoolbag-related pain significantly increased (p<.001). Girls reported significantly more frequent and more severe pain than boys. The logistic model confirmed that adolescent girls are the group at greatest risk of suffering from intense pain. The schoolbag load had a weak impact on back pain, whereas the schoolbag carrying time was a strong predictor. Adolescent girls have the highest risk of experiencing severe back pain, regardless of schoolbag load. This suggests that other factors (anatomical, physiological, or environmental) might play an important role in pain perception. These aspects should be investigated to plan appropriate preventive and rehabilitative strategies. Copyright © 2016 Elsevier Inc. All rights reserved.

Intelligent routing protocol for ad hoc wireless network

NASA Astrophysics Data System (ADS)

Peng, Chaorong; Chen, Chang Wen

2006-05-01

A novel routing scheme for mobile ad hoc networks (MANETs), which combines hybrid and multi-inter-routing path properties with a distributed topology discovery route mechanism using control agents is proposed in this paper. In recent years, a variety of hybrid routing protocols for Mobile Ad hoc wireless networks (MANETs) have been developed. Which is proactively maintains routing information for a local neighborhood, while reactively acquiring routes to destinations beyond the global. The hybrid protocol reduces routing discovery latency and the end-to-end delay by providing high connectivity without requiring much of the scarce network capacity. On the other side the hybrid routing protocols in MANETs likes Zone Routing Protocol still need route "re-discover" time when a route between zones link break. Sine the topology update information needs to be broadcast routing request on local zone. Due to this delay, the routing protocol may not be applicable for real-time data and multimedia communication. We utilize the advantages of a clustering organization and multi-routing path in routing protocol to achieve several goals at the same time. Firstly, IRP efficiently saves network bandwidth and reduces route reconstruction time when a routing path fails. The IRP protocol does not require global periodic routing advertisements, local control agents will automatically monitor and repair broke links. Secondly, it efficiently reduces congestion and traffic "bottlenecks" for ClusterHeads in clustering network. Thirdly, it reduces significant overheads associated with maintaining clusters. Fourthly, it improves clusters stability due to dynamic topology changing frequently. In this paper, we present the Intelligent Routing Protocol. First, we discuss the problem of routing in ad hoc networks and the motivation of IRP. We describe the hierarchical architecture of IRP. We describe the routing process and illustrate it with an example. Further, we describe the control manage mechanisms, which are used to control active route and reduce the traffic amount in the route discovery procedure. Finial, the numerical experiments are given to show the effectiveness of IRP routing protocol.

Group Balance Training Specifically Designed for Individuals With Alzheimer Disease: Impact on Berg Balance Scale, Timed Up and Go, Gait Speed, and Mini-Mental Status Examination.

PubMed

Ries, Julie D; Hutson, Janet; Maralit, Leslie A; Brown, Megan B

2015-01-01

Individuals with Alzheimer disease (IwAD) experience more frequent and more injurious falls than their cognitively intact peers. Evidence of balance and gait dysfunction is observed earlier in the course of Alzheimer disease (AD) than once believed. Balance training has been demonstrated to be effective in improving balance and decreasing falls in cognitively intact older adults but is not well studied in IwAD. This study was designed to analyze the effects of a group balance training program on balance and falls in IwAD. The program was developed specifically for IwAD, with explicit guidelines for communication/interaction and deliberate structure of training sessions catered to the motor learning needs of IwAD. This prospective, quasi-experimental, pretest-posttest design study describes the effects of a balance training program for a cohort of IwAD. Thirty IwAD were recruited from 3 adult day health centers; 22 completed at least 1 posttest session. Participants were tested with Berg Balance Scale (BBS), Timed Up and Go (TUG), Self-Selected Gait Speed (SSGS), Fast Gait Speed (FGS), and Mini-Mental Status Examination (MMSE) immediately before and after the 3-month intervention and again 3 months later. Group training was held at the adult day health centers for 45 minutes, twice per week. Sessions were characterized by massed, constant, and blocked practice of functional, relevant activities with considerable repetition. Ratio of participant to staff member never exceeded 3:1. Physical therapist staff members assured that participants were up on their feet the majority of each session and were individually challenged as much as possible. Repeated-measures analysis of variance (ANOVA) for BBS was significant (F = 15.04; df = 1.67/28.40; P = .000) with post hoc tests, revealing improvement between pretest and immediate posttest (P = .000) and decline in performance between immediate and 3-month posttest (P = .012). Repeated-measures ANOVA posttest for MMSE was significant (F = 5.12; df = 1.73/22.53; P = .018) with post hoc tests, showing no change in MMSE between pretest and immediate posttest but decline in MMSE when comparing immediate posttest with 3-month posttest (P = .038) and pretest with 3-month posttest (P = .019). Repeated-measures ANOVA for TUG, FGS, and SSGS were not significant. Immediate effects of the intervention as assessed by the a priori paired t tests (comparing pre- and immediate posttest data) revealed significant improvement in BBS (t = -7.010; df = 20; P = .000), TUG (t = 3.103; df = 20; P = .006), and FGS (t = -2.115; df = 19; P = .048), but not in SSGS (t = -1.456; df = 20; P = .161). The 3-month group balance training intervention designed specifically for IwAD was effective in improving balance and mobility, as evidenced by improved BBS and TUG performances. Cognition did not decline during the course of the intervention but did decline following the intervention, suggesting a possible protective effect. Given the promising findings, a larger-scale controlled study is warranted.

Distributed XQuery-Based Integration and Visualization of Multimodality Brain Mapping Data

PubMed Central

Detwiler, Landon T.; Suciu, Dan; Franklin, Joshua D.; Moore, Eider B.; Poliakov, Andrew V.; Lee, Eunjung S.; Corina, David P.; Ojemann, George A.; Brinkley, James F.

2008-01-01

This paper addresses the need for relatively small groups of collaborating investigators to integrate distributed and heterogeneous data about the brain. Although various national efforts facilitate large-scale data sharing, these approaches are generally too “heavyweight” for individual or small groups of investigators, with the result that most data sharing among collaborators continues to be ad hoc. Our approach to this problem is to create a “lightweight” distributed query architecture, in which data sources are accessible via web services that accept arbitrary query languages but return XML results. A Distributed XQuery Processor (DXQP) accepts distributed XQueries in which subqueries are shipped to the remote data sources to be executed, with the resulting XML integrated by DXQP. A web-based application called DXBrain accesses DXQP, allowing a user to create, save and execute distributed XQueries, and to view the results in various formats including a 3-D brain visualization. Example results are presented using distributed brain mapping data sources obtained in studies of language organization in the brain, but any other XML source could be included. The advantage of this approach is that it is very easy to add and query a new source, the tradeoff being that the user needs to understand XQuery and the schemata of the underlying sources. For small numbers of known sources this burden is not onerous for a knowledgeable user, leading to the conclusion that the system helps to fill the gap between ad hoc local methods and large scale but complex national data sharing efforts. PMID:19198662

An adaptive density-based routing protocol for flying Ad Hoc networks

NASA Astrophysics Data System (ADS)

Zheng, Xueli; Qi, Qian; Wang, Qingwen; Li, Yongqiang

2017-10-01

An Adaptive Density-based Routing Protocol (ADRP) for Flying Ad Hoc Networks (FANETs) is proposed in this paper. The main objective is to calculate forwarding probability adaptively in order to increase the efficiency of forwarding in FANETs. ADRP dynamically fine-tunes the rebroadcasting probability of a node for routing request packets according to the number of neighbour nodes. Indeed, it is more interesting to privilege the retransmission by nodes with little neighbour nodes. We describe the protocol, implement it and evaluate its performance using NS-2 network simulator. Simulation results reveal that ADRP achieves better performance in terms of the packet delivery fraction, average end-to-end delay, normalized routing load, normalized MAC load and throughput, which is respectively compared with AODV.

Topology for efficient information dissemination in ad-hoc networking

NASA Technical Reports Server (NTRS)

Jennings, E.; Okino, C. M.

2002-01-01

In this paper, we explore the information dissemination problem in ad-hoc wirless networks. First, we analyze the probability of successful broadcast, assuming: the nodes are uniformly distributed, the available area has a lower bould relative to the total number of nodes, and there is zero knowledge of the overall topology of the network. By showing that the probability of such events is small, we are motivated to extract good graph topologies to minimize the overall transmissions. Three algorithms are used to generate topologies of the network with guaranteed connectivity. These are the minimum radius graph, the relative neighborhood graph and the minimum spanning tree. Our simulation shows that the relative neighborhood graph has certain good graph properties, which makes it suitable for efficient information dissemination.

An enhanced performance through agent-based secure approach for mobile ad hoc networks

NASA Astrophysics Data System (ADS)

Bisen, Dhananjay; Sharma, Sanjeev

2018-01-01

This paper proposes an agent-based secure enhanced performance approach (AB-SEP) for mobile ad hoc network. In this approach, agent nodes are selected through optimal node reliability as a factor. This factor is calculated on the basis of node performance features such as degree difference, normalised distance value, energy level, mobility and optimal hello interval of node. After selection of agent nodes, a procedure of malicious behaviour detection is performed using fuzzy-based secure architecture (FBSA). To evaluate the performance of the proposed approach, comparative analysis is done with conventional schemes using performance parameters such as packet delivery ratio, throughput, total packet forwarding, network overhead, end-to-end delay and percentage of malicious detection.

Application of Game Theory Approaches in Routing Protocols for Wireless Networks

NASA Astrophysics Data System (ADS)

Javidi, Mohammad M.; Aliahmadipour, Laya

2011-09-01

An important and essential issue for wireless networks is routing protocol design that is a major technical challenge due to the function of the network. Game theory is a powerful mathematical tool that analyzes the strategic interactions among multiple decision makers and the results of researches show that applied game theory in routing protocol lead to improvement the network performance through reduce overhead and motivates selfish nodes to collaborate in the network. This paper presents a review and comparison for typical representatives of routing protocols designed that applied game theory approaches for various wireless networks such as ad hoc networks, mobile ad hoc networks and sensor networks that all of them lead to improve the network performance.

Protocol Independent Adaptive Route Update for VANET

PubMed Central

Rasheed, Asim; Qayyum, Amir

2014-01-01

High relative node velocity and high active node density have presented challenges to existing routing approaches within highly scaled ad hoc wireless networks, such as Vehicular Ad hoc Networks (VANET). Efficient routing requires finding optimum route with minimum delay, updating it on availability of a better one, and repairing it on link breakages. Current routing protocols are generally focused on finding and maintaining an efficient route, with very less emphasis on route update. Adaptive route update usually becomes impractical for dense networks due to large routing overheads. This paper presents an adaptive route update approach which can provide solution for any baseline routing protocol. The proposed adaptation eliminates the classification of reactive and proactive by categorizing them as logical conditions to find and update the route. PMID:24723807

Increasing the reliability of ecological models using modern software engineering techniques

Treesearch

Robert M. Scheller; Brian R. Sturtevant; Eric J. Gustafson; Brendan C. Ward; David J. Mladenoff

2009-01-01

Modern software development techniques are largely unknown to ecologists. Typically, ecological models and other software tools are developed for limited research purposes, and additional capabilities are added later, usually in an ad hoc manner. Modern software engineering techniques can substantially increase scientific rigor and confidence in ecological models and...

Applying Ad Hoc Institutional Research Findings to College Strategic Planning

ERIC Educational Resources Information Center

Clagett, Craig A.

2004-01-01

Environmental scanning, enrollment forecasting, budget analyses, and institutional effectiveness assessment are examples of the explicit contributions institutional research offices make to campus strategic planning.

Analysing Time to Event Data in Dementia Prevention Trials: The Example of the GuidAge Study of EGb761.

PubMed

Scherrer, B; Andrieu, S; Ousset, P J; Berrut, G; Dartigues, J F; Dubois, B; Pasquier, F; Piette, F; Robert, P; Touchon, J; Garnier, P; Mathiex-Fortunet, H; Vellas, B

2015-12-01

Time-to-event analysis is frequently used in medical research to investigate potential disease-modifying treatments in neurodegenerative diseases. Potential treatment effects are generally evaluated using the logrank test, which has optimal power and sensitivity when the treatment effect (hazard ratio) is constant over time. However, there is generally no prior information as to how the hazard ratio for the event of interest actually evolves. In these cases, the logrank test is not necessarily the most appropriate to use. When the hazard ratio is expected to decrease or increase over time, alternative statistical tests such as the Fleming-Harrington test, provide a better sensitivity. An example of this comes from a large, five-year randomised, placebo-controlled prevention trial (GuidAge) in 2854 community-based subjects making spontaneous memory complaints to their family physicians, which evaluated whether treatment with EGb761 can modify the risk of developing AD. The primary outcome measure was the time to conversion from memory complaint to Alzheimer's type dementia. Although there was no significant difference in the hazard function of conversion between the two treatment groups according to the preplanned logrank test, a significant treatment-by-time interaction for the incidence of AD was observed in a protocol-specified subgroup analysis, suggesting that the hazard ratio is not constant over time. For this reason, additional post hoc analyses were performed using the Fleming-Harrington test to evaluate whether there was a signal of a late effect of EGb761. Applying the Fleming-Harrington test, the hazard function for conversion to dementia in the placebo group was significantly different from that in the EGb761 treatment group (p = 0.0054), suggesting a late effect of EGb761. Since this was a post hoc analysis, no definitive conclusions can be drawn as to the effectiveness of the treatment. This post hoc analysis illustrates the interest of performing another randomised clinical trial of EGb761 explicitly testing the hypothesis of a late treatment effect, as well as of using of better adapted statistical approaches for long term preventive trials when it is expected that prevention cannot have an immediate effect but rather a delayed effect that increases over time.

Assessment of the safety of aquatic animal commodities for international trade: the OIE Aquatic Animal Health code.

PubMed

Oidtmann, B; Johnston, C; Klotins, K; Mylrea, G; Van, P T; Cabot, S; Martin, P Rosado; Ababouch, L; Berthe, F

2013-02-01

Trading of aquatic animals and aquatic animal products has become increasingly globalized during the last couple of decades. This commodity trade has increased the risk for the spread of aquatic animal pathogens. The World Organisation for Animal Health (OIE) is recognized as the international standard-setting organization for measures relating to international trade in animals and animal products. In this role, OIE has developed the Aquatic Animal Health Code, which provides health measures to be used by competent authorities of importing and exporting countries to avoid the transfer of agents pathogenic for animals or humans, whilst avoiding unjustified sanitary barriers. An OIE ad hoc group developed criteria for assessing the safety of aquatic animals or aquatic animal products for any purpose from a country, zone or compartment not declared free from a given disease 'X'. The criteria were based on the absence of the pathogenic agent in the traded commodity or inactivation of the pathogenic agent by the commercial processing used to produce the commodity. The group also developed criteria to assess the safety of aquatic animals or aquatic animal products for retail trade for human consumption from potentially infected areas. Such commodities were assessed considering the form and presentation of the product, the expected volume of waste tissues generated by the consumer and the likely presence of viable pathogenic agent in the waste. The ad hoc group applied the criteria to commodities listed in the individual disease chapters of the Aquatic Animal Health Code (2008 edition). Revised lists of commodities for which no additional measures should be required by the importing countries regardless of the status for disease X of the exporting country were developed and adopted by the OIE World Assembly of Delegates in May 2011. The rationale of the criteria and their application will be explained and demonstrated using examples. © 2012 Crown Copyright. Reproduced with the permission of the Controller of Her Majesty’s Stationery Office and Cefas, Aquatic Animal Disease Group.

Malignant tumors during the first 2 decades of life in the offspring of atomic bomb survivors.

PubMed Central

Yoshimoto, Y; Neel, J V; Schull, W J; Kato, H; Soda, M; Eto, R; Mabuchi, K

1990-01-01

The risk of cancer (incidence) prior to age 20 years has been determined for children born to atomic bomb survivors and to a suitable comparison group. Tumor ascertainment was through death certificates and the tumor registries maintained in Hiroshima and Nagasaki. The rationale for the study stemmed from the evidence that a significant proportion of such childhood tumors as retinoblastoma and Wilms tumor arise on the basis of a mutant gene inherited from one parent plus a second somatic cell mutation involving the allele of this gene. Gonadal radiation doses were calculated by the recently established DS86 system, supplemented by an ad hoc system for those children for one or both of whose parents a DS86 dose could not be computed but for whom an ad hoc dose could be developed on the basis of the available information. The total data set consisted of (1) a cohort of 31,150 live-born children one or both of whose parents received greater than 0.01 Sv of radiation at the time of the atomic bombings (average conjoint gonad exposure 0.43 Sv) and (2) two suitable comparison groups totaling 41,066 children. Altogether, 43 malignant tumors were ascertained in the children of exposed parents, and 49 malignant tumors were ascertained in the two control groups. A multiple linear regression analysis revealed no increase in malignancy in the children of exposed parents. However, examination of the data suggested that only 3.0-5.0% of the tumors of childhood that were observed in the comparison groups are associated with an inherited genetic predisposition that would be expected to exhibit an altered frequency if the parental mutation rate were increased. There is thus far no confirmation of the positive findings that Nomura found in a mouse system. PMID:2160192

Program status

NASA Technical Reports Server (NTRS)

Smith, P.

1986-01-01

The Pilot Climate Data System (PCDS) was designed to support a variety of users that have been arbitrarily categorized into four groups: researchers, data producers, occasional users, and management. The expanding capabilities of the system are attracting the attention of both academic and other scientific institutions worldwide. Highlighted by progress in networking capabilities, hardware acquisitions, software developments, data set additions, and tutorial developments, exciting advances have taken place since the First PCDS Workshop. In the plans for the 1986 fiscal year, recommendations from an ad hoc users' group meeting in May 1985 and from the First PCDS workshop are apparent. This year's plans are listed, along with comments made at the users' group meeting. Although the PCDS is presently considered to be in a developmental phase, plans for making the transition to an operational phase are being implemented.

Semantic querying of relational data for clinical intelligence: a semantic web services-based approach

PubMed Central

2013-01-01

Background Clinical Intelligence, as a research and engineering discipline, is dedicated to the development of tools for data analysis for the purposes of clinical research, surveillance, and effective health care management. Self-service ad hoc querying of clinical data is one desirable type of functionality. Since most of the data are currently stored in relational or similar form, ad hoc querying is problematic as it requires specialised technical skills and the knowledge of particular data schemas. Results A possible solution is semantic querying where the user formulates queries in terms of domain ontologies that are much easier to navigate and comprehend than data schemas. In this article, we are exploring the possibility of using SADI Semantic Web services for semantic querying of clinical data. We have developed a prototype of a semantic querying infrastructure for the surveillance of, and research on, hospital-acquired infections. Conclusions Our results suggest that SADI can support ad-hoc, self-service, semantic queries of relational data in a Clinical Intelligence context. The use of SADI compares favourably with approaches based on declarative semantic mappings from data schemas to ontologies, such as query rewriting and RDFizing by materialisation, because it can easily cope with situations when (i) some computation is required to turn relational data into RDF or OWL, e.g., to implement temporal reasoning, or (ii) integration with external data sources is necessary. PMID:23497556

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.

Linking Satellites Via Earth "Hot Spots" and the Internet to Form Ad Hoc Constellations

NASA Technical Reports Server (NTRS)

Mandl, Dan; Frye, Stu; Grosvenor, Sandra; Ingram, Mary Ann; Langley, John; Miranda, Felix; Lee, Richard Q.; Romanofsky, Robert; Zaman, Afoz; Popovic, Zoya

2004-01-01

As more assets are placed in orbit, opportunities emerge to combine various sets of satellites in temporary constellations to perform collaborative image collections. Often, new operations concepts for a satellite or set of satellites emerge after launch. To the degree with which new space assets can be inexpensively and rapidly integrated into temporary or "ad hoc" constellations, will determine whether these new ideas will be implemented or not. On the Earth Observing 1 (EO-1) satellite, a New Millennium Program mission, a number of experiments were conducted and are being conducted to demonstrate various aspects of an architecture that, when taken as a whole, will enable progressive mission autonomy. In particular, the target architecture will use adaptive ground antenna arrays to form, as close as possible, the equivalent of wireless access points for low earth orbiting satellites. Coupled with various ground and flight software and the Internet. the architecture enables progressive mission autonomy. Thus, new collaborative sensing techniques can be implemented post-launch. This paper will outline the overall operations concept and highlight details of both the research effort being conducted in

Advancing intercultural competency: Canadian engineering employers' experiences with immigrant engineers

NASA Astrophysics Data System (ADS)

Friesen, Marcia; Ingram, Sandra

2013-05-01

This paper explores Canadian engineering employers' perceptions of and experiences with internationally educated engineers (recent immigrants to Canada) employed in their organisations for varying lengths of time. Qualitative data were collected from employers using focus group methodology. Findings reflected employers' observations of culturally different behaviours and characteristics in their internationally educated employees, employers' reactions to cultural differences ranging from negative attributions to tolerance, and the implementation of largely ad hoc intra-organisational strategies for managing cultural differences in employer-employee relationships. Findings exposed the lack of corporate intercultural competency in the Canadian engineering profession. Equity and gatekeeping implications are discussed.

Science opportunity analyzer - a multi-mission approach to science planning

NASA Technical Reports Server (NTRS)

Streiffert, B. A.; Polanskey, C. A.; O'Reilly, T.; Colwell, J.

2003-01-01

In the past Science Planning for space missions has been comprised of using ad-hoc software toolscollected or reconstructed from previous missions, tools used by other groups who often speak a different 'technical' language or even 'the backs of envelopes'. In addition to the tools being rough, the work done with these tools often has had to be redone or at least re-entered when it came time to determine actual observations. Science Opportunity Analyzer (SOA), a Java-based application, has been built for scientists to enable them to identify/analyze observation opportunities and then, to create corresponding observation designs.

NGST Science Instruments and Process

NASA Technical Reports Server (NTRS)

Mather, John

1999-01-01

Possible NGST (Next Generation Space Telescope) instruments have been studied by NASA, ESA (European Space Agency), and CSA (Canadian Space Agency) teams, and their reports were presented at this meeting and published on the NGST web sites. The instrument capabilities will be evaluated by the Ad Hoc Science Working Group and the technical readiness will be reviewed by a technical panel. Recommendations will be made to the NASA Project Scientist, who will present a report for public comment. NASA. ESA, and the CSA will then allocate instrument, responsibilities in early 2000. NASA will choose its scientific investigations with instruments in 2002.

Sweat lipid mediator profiling: a noninvasive approach for cutaneous research[S

PubMed Central

Hassoun, Lauren A.; Foolad, Negar; Pedersen, Theresa L.; Sivamani, Raja K.; Newman, John W.

2017-01-01

Recent advances in analytical and sweat collection techniques provide new opportunities to identify noninvasive biomarkers for the study of skin inflammation and repair. This study aims to characterize the lipid mediator profile including oxygenated lipids, endocannabinoids, and ceramides/sphingoid bases in sweat and identify differences in these profiles between sweat collected from nonlesional sites on the unflared volar forearm of subjects with and without atopic dermatitis (AD). Adapting routine procedures developed for plasma analysis, over 100 lipid mediators were profiled using LC-MS/MS and 58 lipid mediators were detected in sweat. Lipid mediator concentrations were not affected by sampling or storage conditions. Increases in concentrations of C30–C40 [NS] and [NdS] ceramides, and C18:1 sphingosine, were observed in the sweat of study participants with AD despite no differences being observed in transepidermal water loss between study groups, and this effect was strongest in men (P < 0.05, one-way ANOVA with Tukey’s post hoc HSD). No differences in oxylipins and endocannabinoids were observed between study groups. Sweat mediator profiling may therefore provide a noninvasive diagnostic for AD prior to the presentation of clinical signs. PMID:27875258

Sweat lipid mediator profiling: a noninvasive approach for cutaneous research.

PubMed

Agrawal, Karan; Hassoun, Lauren A; Foolad, Negar; Pedersen, Theresa L; Sivamani, Raja K; Newman, John W

2017-01-01

Recent advances in analytical and sweat collection techniques provide new opportunities to identify noninvasive biomarkers for the study of skin inflammation and repair. This study aims to characterize the lipid mediator profile including oxygenated lipids, endocannabinoids, and ceramides/sphingoid bases in sweat and identify differences in these profiles between sweat collected from nonlesional sites on the unflared volar forearm of subjects with and without atopic dermatitis (AD). Adapting routine procedures developed for plasma analysis, over 100 lipid mediators were profiled using LC-MS/MS and 58 lipid mediators were detected in sweat. Lipid mediator concentrations were not affected by sampling or storage conditions. Increases in concentrations of C30-C40 [NS] and [NdS] ceramides, and C18:1 sphingosine, were observed in the sweat of study participants with AD despite no differences being observed in transepidermal water loss between study groups, and this effect was strongest in men (P < 0.05, one-way ANOVA with Tukey's post hoc HSD). No differences in oxylipins and endocannabinoids were observed between study groups. Sweat mediator profiling may therefore provide a noninvasive diagnostic for AD prior to the presentation of clinical signs.

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

PubMed

Kuscu, Murat; Akan, Ozgur B

2014-09-01

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

Proposal of a service delivery integration index of home care for older persons: application in several European cities

PubMed Central

Henrard, Jean-Claude; Ankri, Joël; Frijters, Dinnus; Carpenter, Iain; Topinkova, Eva; Garms-Homolova, Vjenka; Finne-Soveri, Harriett; Sørbye, Liv Wergeland; Jónsson, Palmi V.; Ljunggren, Gunnar; Schroll, Marianne; Wagner, Cordula; Bernabei, Roberto

2006-01-01

Abstract Purpose To propose an integration index of home care delivery to older persons, to study its validity and to apply it to home care services of European cities. Theory Home care delivery integration was based on two dimensions referring to process-centred integration and organisational structure approach. Method Items considered as part of both dimensions according to an expert consensus (face validity) were extracted from a standardised questionnaire used in “Aged in Home care” (AdHoc) study to capture basic characteristics of home care services. Their summation leads to a services' delivery integration index. This index was applied to AdHoc services. A factor analysis was computed in order to empirically test the validity of the theoretical constructs. The plot of the settings was performed. Results Application of the index ranks home care services in four groups according to their score. Factor analysis identifies a first factor which opposes working arrangement within service to organisational structure bringing together provisions for social care. A second factor corresponds to basic nursing care and therapies. Internal consistency for those three domains ranges from 0.78 to 0.93. When plotting the different settings different models of service delivery appear. Conclusion The proposed index shows that behind a total score several models of care delivery are hidden. Comparison of service delivery integration should take into account this heterogeneity. PMID:17006549

On service differentiation in mobile Ad Hoc networks.

PubMed

Zhang, Shun-liang; Ye, Cheng-qing

2004-09-01

A network model is proposed to support service differentiation for mobile Ad Hoc networks by combining a fully distributed admission control approach and the DIFS based differentiation mechanism of IEEE802.11. It can provide different kinds of QoS (Quality of Service) for various applications. Admission controllers determine a committed bandwidth based on the reserved bandwidth of flows and the source utilization of networks. Packets are marked when entering into networks by markers according to the committed rate. By the mark in the packet header, intermediate nodes handle the received packets in different manners to provide applications with the QoS corresponding to the pre-negotiated profile. Extensive simulation experiments showed that the proposed mechanism can provide QoS guarantee to assured service traffic and increase the channel utilization of networks.

Immune Inspired Security Approach for Manets: a Case Study

NASA Astrophysics Data System (ADS)

Mohamed, Yasir Abdelgadir

2011-06-01

This paper extends the work that has earlier been established. Immune inspired approach for securing mobile ad hoc networks is specified there. Although it is clearly indicated there that the research scope is the wireless networks in general and hybrid mobile ad hoc networks in particular, we have seen that specifying the security system in one of the communications applications that need further security approach may help to understand how effectively the system can contribute to this vital and important networks sector. Security in this type of networks is important and controversial as it plays a key role in users' eagerness or reluctance for the services provided by these networks. In this paper, the immune inspired security system is specified to secure web services in converged networks.

A high performance, ad-hoc, fuzzy query processing system for relational databases

NASA Technical Reports Server (NTRS)

Mansfield, William H., Jr.; Fleischman, Robert M.

1992-01-01

Database queries involving imprecise or fuzzy predicates are currently an evolving area of academic and industrial research. Such queries place severe stress on the indexing and I/O subsystems of conventional database environments since they involve the search of large numbers of records. The Datacycle architecture and research prototype is a database environment that uses filtering technology to perform an efficient, exhaustive search of an entire database. It has recently been modified to include fuzzy predicates in its query processing. The approach obviates the need for complex index structures, provides unlimited query throughput, permits the use of ad-hoc fuzzy membership functions, and provides a deterministic response time largely independent of query complexity and load. This paper describes the Datacycle prototype implementation of fuzzy queries and some recent performance results.

Introduction to Blueweb: A Decentralized Scatternet Formation Algorithm for Bluetooth Ad Hoc Networks

NASA Astrophysics Data System (ADS)

Yu, Chih-Min; Huang, Chia-Chi

In this letter, a decentralized scatternet formation algorithm called Bluelayer is proposed. First, Bluelayer uses a designated root to construct a tree-shaped subnet and propagates an integer variable k1 called counter limit as well as a constant k in its downstream direction to determine new roots. Then each new root asks its upstream master to start a return connection procedure to convert the tree-shaped subnet into a web-shaped subnet for its immediate upstream root. At the same time, each new root repeats the same procedure as the root to build its own subnet until the whole scatternet is formed. Simulation results show that Bluelayer achieves good network scalability and generates an efficient scatternet configuration for various sizes of Bluetooth ad hoc network.

An ultra-wide bandwidth-based range/GPS tight integration approach for relative positioning in vehicular ad hoc networks

NASA Astrophysics Data System (ADS)

Shen, Feng; Wayn Cheong, Joon; Dempster, Andrew G.

2015-04-01

Relative position awareness is a vital premise for the implementation of emerging intelligent transportation systems, such as collision warning. However, commercial global navigation satellite systems (GNSS) receivers do not satisfy the requirements of these applications. Fortunately, cooperative positioning (CP) techniques, through sharing the GNSS measurements between vehicles, can improve the performance of relative positioning in a vehicular ad hoc network (VANET). In this paper, while assuming there are no obstacles between vehicles, a new enhanced tightly coupled CP technique is presented by adding ultra-wide bandwidth (UWB)-based inter-vehicular range measurements. In the proposed CP method, each vehicle fuses the GPS measurements and the inter-vehicular range measurements. Based on analytical and experimental results, in the full GPS coverage environment, the new tight integration CP method outperforms the INS-aided tight CP method, tight CP method, and DGPS by 11%, 15%, and 24%, respectively; in the GPS outage scenario, the performance improvement achieves 60%, 65%, and 73%, respectively.

ESSC-ESF Position Paper-Science-Driven Scenario for Space Exploration: Report from the European Space Sciences Committee (ESSC)

NASA Astrophysics Data System (ADS)

Worms, Jean-Claude; Lammer, Helmut; Barucci, Antonella; Beebe, Reta; Bibring, Jean-Pierre; Blamont, Jacques; Blanc, Michel; Bonnet, Roger; Brucato, John R.; Chassefière, Eric; Coradini, Angioletta; Crawford, Ian; Ehrenfreund, Pascale; Falcke, Heino; Gerzer, Rupert; Grady, Monica; Grande, Manuel; Haerendel, Gerhard; Horneck, Gerda; Koch, Bernhard; Lobanov, Andreï; Lopez-Moreno, José J.; Marco, Robert; Norsk, Peter; Rothery, Dave; Swings, Jean-Pierre; Tropea, Cam; Ulamec, Stephan; Westall, Frances; Zarnecki, John

2009-02-01

In 2005 the then ESA Directorate for Human Spaceflight, Microgravity and Exploration (D-HME) commissioned a study from the European Science Foundation's (ESF) European Space Sciences Committee (ESSC) to examine the science aspects of the Aurora Programme in preparation for the December 2005 Ministerial Conference of ESA Member States, held in Berlin. A first interim report was presented to ESA at the second stakeholders meeting on 30 and 31 May 2005. A second draft report was made available at the time of the final science stakeholders meeting on 16 September 2005 in order for ESA to use its recommendations to prepare the Executive proposal to the Ministerial Conference. The final ESSC report on that activity came a few months after the Ministerial Conference (June 2006) and attempted to capture some elements of the new situation after Berlin, and in the context of the reduction in NASA's budget that was taking place at that time; e.g., the postponement sine die of the Mars Sample Return mission. At the time of this study, ESSC made it clear to ESA that the timeline imposed prior to the Berlin Conference had not allowed for a proper consultation of the relevant science community and that this should be corrected in the near future. In response to that recommendation, ESSC was asked again in the summer of 2006 to initiate a broad consultation to define a science-driven scenario for the Aurora Programme. This exercise ran between October 2006 and May 2007. ESA provided the funding for staff support, publication costs, and costs related to meetings of a Steering Group, two meetings of a larger ad hoc group (7 and 8 December 2006 and 8 February 2007), and a final scientific workshop on 15 and 16 May 2007 in Athens. As a result of these meetings a draft report was produced and examined by the Ad Hoc Group. Following their endorsement of the report and its approval by the plenary meeting of the ESSC, the draft report was externally refereed, as is now normal practice with all ESSC-ESF reports, and amended accordingly. The Ad Hoc Group defined overarching scientific goals for Europe's exploration programme, dubbed "Emergence and co-evolution of life with its planetary environments," focusing on those targets that can ultimately be reached by humans, i.e., Mars, the Moon, and Near Earth Objects. Mars was further recognized as the focus of that programme, with Mars sample return as the recognized primary goal; furthermore the report clearly states that Europe should position itself as a major actor in defining and leading Mars sample return missions. The report is reproduced in this article. On 26 November 2008 the Ministers of ESA Member States decided to give a high strategic priority to the robotic exploration programme of Mars by funding the enhanced ExoMars mission component, in line therefore with the recommendations from this ESSC-ESF report.

ESSC-ESF position paper--science-driven scenario for space exploration: report from the European Space Sciences Committee (ESSC).

PubMed

Worms, Jean-Claude; Lammer, Helmut; Barucci, Antonella; Beebe, Reta; Bibring, Jean-Pierre; Blamont, Jacques; Blanc, Michel; Bonnet, Roger; Brucato, John R; Chassefière, Eric; Coradini, Angioletta; Crawford, Ian; Ehrenfreund, Pascale; Falcke, Heino; Gerzer, Rupert; Grady, Monica; Grande, Manuel; Haerendel, Gerhard; Horneck, Gerda; Koch, Bernhard; Lobanov, Andreï; Lopez-Moreno, José J; Marco, Roberto; Norsk, Peter; Rothery, Dave; Swings, Jean-Pierre; Tropea, Cam; Ulamec, Stephan; Westall, Frances; Zarnecki, John

2009-01-01

In 2005 the then ESA Directorate for Human Spaceflight, Microgravity and Exploration (D-HME) commissioned a study from the European Science Foundation's (ESF) European Space Sciences Committee (ESSC) to examine the science aspects of the Aurora Programme in preparation for the December 2005 Ministerial Conference of ESA Member States, held in Berlin. A first interim report was presented to ESA at the second stakeholders meeting on 30 and 31 May 2005. A second draft report was made available at the time of the final science stakeholders meeting on 16 September 2005 in order for ESA to use its recommendations to prepare the Executive proposal to the Ministerial Conference. The final ESSC report on that activity came a few months after the Ministerial Conference (June 2006) and attempted to capture some elements of the new situation after Berlin, and in the context of the reduction in NASA's budget that was taking place at that time; e.g., the postponement sine die of the Mars Sample Return mission. At the time of this study, ESSC made it clear to ESA that the timeline imposed prior to the Berlin Conference had not allowed for a proper consultation of the relevant science community and that this should be corrected in the near future. In response to that recommendation, ESSC was asked again in the summer of 2006 to initiate a broad consultation to define a science-driven scenario for the Aurora Programme. This exercise ran between October 2006 and May 2007. ESA provided the funding for staff support, publication costs, and costs related to meetings of a Steering Group, two meetings of a larger ad hoc group (7 and 8 December 2006 and 8 February 2007), and a final scientific workshop on 15 and 16 May 2007 in Athens. As a result of these meetings a draft report was produced and examined by the Ad Hoc Group. Following their endorsement of the report and its approval by the plenary meeting of the ESSC, the draft report was externally refereed, as is now normal practice with all ESSC-ESF reports, and amended accordingly. The Ad Hoc Group defined overarching scientific goals for Europe's exploration programme, dubbed "Emergence and co-evolution of life with its planetary environments," focusing on those targets that can ultimately be reached by humans, i.e., Mars, the Moon, and Near Earth Objects. Mars was further recognized as the focus of that programme, with Mars sample return as the recognized primary goal; furthermore the report clearly states that Europe should position itself as a major actor in defining and leading Mars sample return missions. The report is reproduced in this article. On 26 November 2008 the Ministers of ESA Member States decided to give a high strategic priority to the robotic exploration programme of Mars by funding the enhanced ExoMars mission component, in line therefore with the recommendations from this ESSC-ESF report.

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 Implementation of Secure Area Expansion Scheme for Public Wireless LAN Services

NASA Astrophysics Data System (ADS)

Watanabe, Ryu; Tanaka, Toshiaki

Recently, wireless LAN (WLAN) technology has become a major wireless communication method. The communication bandwidth is increasing and speeds have attained rates exceeding 100 Mbps. Therefore, WLAN technology is regarded as one of the promising communication methods for future networks. In addition, public WLAN connection services can be used in many locations. However, the number of the access points (AP) is insufficient for seamless communication and it cannot be said that users can use the service ubiquitously. An ad-hoc network style connection can be used to expand the coverage area of a public WLAN service. By relaying the user messages among the user nodes, a node can obtain an Internet connection via an AP, even though the node is located outside the AP's direct wireless connection area. Such a coverage area extending technology has many advantages thanks to the feature that no additional infrastructure is required. Therefore, there is a strong demand for this technology as it allows the cost-effective construction of future networks. When a secure ad-hoc routing protocol is used for message exchange in the WLAN service, the message routes are protected from malicious behavior such as route forging and can be maintained appropriately. To do this, however, a new node that wants to join the WLAN service has to obtain information such as the public key certificate and IP address in order to start secure ad-hoc routing. In other words, an initial setup is required for every network node to join the WLAN service properly. Ordinarily, such information should be assigned from the AP. However, new nodes cannot always contact an AP directly. Therefore, there are problems about information delivery in the initial setup of a network node. These problems originate in the multi hop connection based on the ad-hoc routing protocols. In order to realize an expanded area WLAN service, in this paper, the authors propose a secure public key certificate and address provision scheme during the initial setup phase on mobile nodes for the service. The proposed scheme also considers the protection of user privacy. Accordingly, none of the user nodes has to reveal their unique and persistent information to other nodes. Instead of using such information, temporary values are sent by an AP to mobile nodes and used for secure ad-hoc routing operations. Therefore, our proposed scheme prevents tracking by malicious parties by avoiding the use of unique information. Moreover, a test bed was also implemented based on the proposal and an evaluation was carried out in order to confirm performance. In addition, the authors describe a countermeasure against denial of service (DoS) attacks based on the approach to privacy protection described in our proposal.

Isolation of pandemic Vibrio parahaemolyticus from UK water and shellfish produce.

PubMed

Powell, Andy; Baker-Austin, Craig; Wagley, Sariqa; Bayley, Amanda; Hartnell, Rachel

2013-05-01

Vibrio parahaemolyticus is a Gram-negative, halophilic bacterium found commonly in temperate and warm estuarine waters worldwide. V. parahaemolyticus is considered an emerging bacterial pathogen in Europe and has been responsible for several recent seafood-associated outbreaks. During ad hoc testing of raw shellfish produce in May 2012, pandemic group (O3:K6) V. parahaemolyticus was isolated from Pacific oysters (Crassostrea gigas), harvested in Southern England. Follow-on testing of water and shellfish, encompassing a small number geographically diverse sites, also retrieved pandemic group isolates. These strains are amongst the most northerly pandemic strains described to date and represent the first instance of pandemic V. parahaemolyticus isolated in the UK, highlighting the expanding geographical distribution of these foodborne pathogens in the environment.

76 FR 43987 - Pacific Fishery Management Council; Public Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-22

... Pacific Fishery Management Council's (Pacific Council) ad hoc groundfish Essential Fish Habitat Review... of groundfish Essential Fish Habitat (EFH). DATES: The work session will be held Thursday, October 6...

Intelligent self-organization methods for wireless ad hoc sensor networks based on limited resources

NASA Astrophysics Data System (ADS)

Hortos, William S.

2006-05-01

A wireless ad hoc sensor network (WSN) is a configuration for area surveillance that affords rapid, flexible deployment in arbitrary threat environments. There is no infrastructure support and sensor nodes communicate with each other only when they are in transmission range. To a greater degree than the terminals found in mobile ad hoc networks (MANETs) for communications, sensor nodes are resource-constrained, with limited computational processing, bandwidth, memory, and power, and are typically unattended once in operation. Consequently, the level of information exchange among nodes, to support any complex adaptive algorithms to establish network connectivity and optimize throughput, not only deplete those limited resources and creates high overhead in narrowband communications, but also increase network vulnerability to eavesdropping by malicious nodes. Cooperation among nodes, critical to the mission of sensor networks, can thus be disrupted by the inappropriate choice of the method for self-organization. Recent published contributions to the self-configuration of ad hoc sensor networks, e.g., self-organizing mapping and swarm intelligence techniques, have been based on the adaptive control of the cross-layer interactions found in MANET protocols to achieve one or more performance objectives: connectivity, intrusion resistance, power control, throughput, and delay. However, few studies have examined the performance of these algorithms when implemented with the limited resources of WSNs. In this paper, self-organization algorithms for the initiation, operation and maintenance of a network topology from a collection of wireless sensor nodes are proposed that improve the performance metrics significant to WSNs. The intelligent algorithm approach emphasizes low computational complexity, energy efficiency and robust adaptation to change, allowing distributed implementation with the actual limited resources of the cooperative nodes of the network. Extensions of the algorithms from flat topologies to two-tier hierarchies of sensor nodes are presented. Results from a few simulations of the proposed algorithms are compared to the published results of other approaches to sensor network self-organization in common scenarios. The estimated network lifetime and extent under static resource allocations are computed.

75 FR 67688 - Pacific Fishery Management Council; Public Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-03

... Pacific Fishery Management Council's (Council's) Ad Hoc Groundfish Essential Fish Habitat Review Committee... groundfish Essential Fish Habitat (EFH). DATES: The work session will be held Monday, December 20, 2010 from...

The influence of black carbon on the sorption and desorption of two model PAHs in natural soils.

PubMed

Chi, Fung-Hwa

2014-01-01

Black carbons (BC) which result from the incomplete combustion of farm waste [man-made (burned) BC] are highly absorbent. In Taiwan, the burning of farm waste known as slash and burn is common. The BCs from the burning may present an environmental challenge. Little is known about the effect of BCs on the transport of hydrophobic organic contaminants (HOC). This study investigates the sorption of anthracene and naphthalene to BCs in soil and efficiency of the surfactants Tween 80 and Triton X-100 in their removal. Both surfactants demonstrated 2-6 times increased solubility in the soils with the addiction of BC. Column experiments were performed to imitate the transportation of these contaminants in groundwater through soils before and after adding BC produced by burning farm waste in the lab. We found significantly increased sorption of anthracene in soil added with BCs produced in the lab, suggesting that fraction of organic carbon (foc) can contribute to sorption of such HOCs. Sorption of naphthalene was increased but not significantly. Comparing the concentrations of contaminants, we found the soil containing BC from burned farm waste absorbed HOC more efficiently than the organic BC (naturally-occurring) in the original soil. Therefore, sorption capacity and influence on the transport of HOC cannot be estimated simply by the foc of the soil because the two BCs differ greatly in their sorption ability. BC from farm waste absorbs more contaminants than naturally occurring BC in the soil.

Ad hoc cost analysis of the new gastrointestinal bleeding algorithm in patients with ventricular assist device.

PubMed

Hirose, Hitoshi; Sarosiek, Konrad; Cavarocchi, Nicholas C

2014-01-01

Gastrointestinal bleed (GIB) is a known complication in patients receiving nonpulsatile ventricular assist devices (VAD). Previously, we reported a new algorithm for the workup of GIB in VAD patients using deep bowel enteroscopy. In this new algorithm, patients underwent fewer procedures, received less transfusions, and took less time to make the diagnosis than the traditional GIB algorithm group. Concurrently, we reviewed the cost-effectiveness of this new algorithm compared with the traditional workup. The procedure charges for the diagnosis and treatment of each episode of GIB was ~ $2,902 in the new algorithm group versus ~ $9,013 in the traditional algorithm group (p < 0.0001). Following the new algorithm in VAD patients with GIB resulted in fewer transfusions and diagnostic tests while attaining a substantial cost savings per episode of bleeding.

FHWA White Paper on Mobile Ad Hoc Networks

DOT National Transportation Integrated Search

2018-01-01

Advanced next generation communications technologies offer the potential to greatly improve safety, system efficiency, and mobility across our Nations roadways. These new technologies and processes can address both traditionally difficult as well ...

44 CFR 351.10 - Establishment of committees.

Code of Federal Regulations, 2010 CFR

2010-10-01

... appropriate and on an ad hoc basis, other Federal departments and agencies. In chairing the committee, FEMA... guidance and orientation to other agency members to assist them in carrying out their functions. 1 I...

76 FR 2084 - Pacific Fishery Management Council; Public Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-12

... Pacific Fishery Management Council's (Council) Ad Hoc Groundfish Process Improvement Committee (PIC) will... the PIC work session is to develop an optimum detailed process and schedule for the 2013-14 groundfish...

American Association of Tissue Banks

MedlinePlus

... Committees Accreditation American Board of Tissue Banking Bylaws / Ethics Communications Donor Family Services Ad Hoc Committee Education Finance ... Bureau Accredited Bank Search Bookstore Bulletins Global Topics Communications & Media Job Center News Releases Patients and Community Useful ...

Sailing ships for research

NASA Astrophysics Data System (ADS)

Richman, Barbara T.

Motor-assisted sailing ships for ocean research could perform as well as or better than many existing research vessels and could cut fuel consumption by 50-80%, according to a preliminary study by an ad hoc panel of the National Research Council's Ocean Sciences Board (OSB).Rising fuel costs plague ship owners and operators. For example, 2 years ago the U.S. oceanographic fleet had a $6 million overrun in fuel costs. Furthermore, the price of marine diesel fuel skyrocketed from $3 per barrel in 1972 to about $38 per barrel in late 1980. Cutting these costs would be welcome if the savings were not made at the expense of additional crew, longer transit times, or less efficient scientific operations. A sailing ship with auxiliary motor propulsion is a promising prospect, according to the Ad Hoc Panel on the Use of Sailing Ships for Oceanography.

Studying the complex spectral line profiles in the spectra of hot emission stars and quasars .

NASA Astrophysics Data System (ADS)

Danezis, E.; Lyratzi, E.; Antoniou, A.; Popović, L. Č.; Dimitrijević, M. S.

Some Hot Emission Stars and AGNs present peculiar spectral line profiles which are due to DACs and SACs phenomena. The origin and the mechanisms which are responsible for the creation of DACs/SACs is an important problem that has been studied by many researchers. This paper is a review of our efforts to study the origin and the mechanisms of these phenomena. At first we present a theoretic ad hoc picture for the structure of the plasma that surrounds the specific category of hot emission stars that present DACs or SACs. Then we present the mathematical model that we constructed, which is based on the properties of the above ad hoc theoretical structure. Finally, we present some results from our statistical studies that prove the consistency of our model with the classical physical theory.

Ecology Based Decentralized Agent Management System

NASA Technical Reports Server (NTRS)

Peysakhov, Maxim D.; Cicirello, Vincent A.; Regli, William C.

2004-01-01

The problem of maintaining a desired number of mobile agents on a network is not trivial, especially if we want a completely decentralized solution. Decentralized control makes a system more r e bust and less susceptible to partial failures. The problem is exacerbated on wireless ad hoc networks where host mobility can result in significant changes in the network size and topology. In this paper we propose an ecology-inspired approach to the management of the number of agents. The approach associates agents with living organisms and tasks with food. Agents procreate or die based on the abundance of uncompleted tasks (food). We performed a series of experiments investigating properties of such systems and analyzed their stability under various conditions. We concluded that the ecology based metaphor can be successfully applied to the management of agent populations on wireless ad hoc networks.

Implementing MANETS in Android based environment using Wi-Fi direct

NASA Astrophysics Data System (ADS)

Waqas, Muhammad; Babar, Mohammad Inayatullah Khan; Zafar, Mohammad Haseeb

2015-05-01

Packet loss occurs in real-time voice transmission over wireless broadcast Ad-hoc network which creates disruptions in sound. Basic objective of this research is to design a wireless Ad-hoc network based on two Android devices by using the Wireless Fidelity (WIFI) Direct Application Programming Interface (API) and apply the Network Codec, Reed Solomon Code. The network codec is used to encode the data of a music wav file and recover the lost packets if any, packets are dropped using a loss module at the transmitter device to analyze the performance with the objective of retrieving the original file at the receiver device using the network codec. This resulted in faster transmission of the files despite dropped packets. In the end both files had the original formatted music files with complete performance analysis based on the transmission delay.

Worm epidemics in wireless ad hoc networks

NASA Astrophysics Data System (ADS)

Nekovee, Maziar

2007-06-01

A dramatic increase in the number of computing devices with wireless communication capability has resulted in the emergence of a new class of computer worms which specifically target such devices. The most striking feature of these worms is that they do not require Internet connectivity for their propagation but can spread directly from device to device using a short-range radio communication technology, such as WiFi or Bluetooth. In this paper, we develop a new model for epidemic spreading of these worms and investigate their spreading in wireless ad hoc networks via extensive Monte Carlo simulations. Our studies show that the threshold behaviour and dynamics of worm epidemics in these networks are greatly affected by a combination of spatial and temporal correlations which characterize these networks, and are significantly different from the previously studied epidemics in the Internet.

Robotic disaster recovery efforts with ad-hoc deployable cloud computing

NASA Astrophysics Data System (ADS)

Straub, Jeremy; Marsh, Ronald; Mohammad, Atif F.

2013-06-01

Autonomous operations of search and rescue (SaR) robots is an ill posed problem, which is complexified by the dynamic disaster recovery environment. In a typical SaR response scenario, responder robots will require different levels of processing capabilities during various parts of the response effort and will need to utilize multiple algorithms. Placing these capabilities onboard the robot is a mediocre solution that precludes algorithm specific performance optimization and results in mediocre performance. Architecture for an ad-hoc, deployable cloud environment suitable for use in a disaster response scenario is presented. Under this model, each service provider is optimized for the task and maintains a database of situation-relevant information. This service-oriented architecture (SOA 3.0) compliant framework also serves as an example of the efficient use of SOA 3.0 in an actual cloud application.

The dynamical origin of multiple populations in intermediate-age clusters in the Magellanic Clouds

NASA Astrophysics Data System (ADS)

Hong, Jongsuk; de Grijs, Richard; Askar, Abbas; Berczik, Peter; Li, Chengyuan; Wang, Long; Deng, Licai; Kouwenhoven, M. B. N.; Giersz, Mirek; Spurzem, Rainer

2017-11-01

Numerical simulations were carried out to study the origin of multiple stellar populations in the intermediate-age clusters NGC 411 and NGC 1806 in the Magellanic Clouds. We performed NBODY6++ simulations based on two different formation scenarios, an ad hoc formation model where second-generation (SG) stars are formed inside a cluster of first-generation (FG) stars using the gas accumulated from the external intergalactic medium and a minor merger model of unequal mass (MSG/MFG ∼ 5-10 per cent) clusters with an age difference of a few hundred million years. We compared our results such as the radial profile of the SG-to-FG number ratio with observations on the assumption that the SG stars in the observations are composed of cluster members, and confirmed that both the ad hoc formation and merger scenarios reproduce the observed radial trend of the SG-to-FG number ratio, which shows less centrally concentrated SG than FG stars. It is difficult to constrain the formation scenario for the multiple populations by only using the spatial distribution of the SG stars. SG stars originating from the merger scenario show a significant velocity anisotropy and rotational features compared to those from the ad hoc formation scenario. Thus, observations aimed at kinematic properties like velocity anisotropy or rotational velocities for SG stars should be obtained to better understand the formation of the multiple populations in these clusters. This is, however, beyond current instrumentation capabilities.

EPA scientific integrity policy draft

NASA Astrophysics Data System (ADS)

Showstack, Randy

2011-08-01

The U.S. Environmental Protection Agency (EPA) issued its draft scientific integrity policy on 5 August. The draft policy addresses scientific ethical standards, communications with the public, the use of advisory committees and peer review, and professional development. The draft policy was developed by an ad hoc group of EPA senior staff and scientists in response to a December 2010 memorandum on scientific integrity from the White House Office of Science and Technology Policy. The agency is accepting public comments on the draft through 6 September; comments should be sent to osa.staff@epa.gov. For more information, see http://www.epa.gov/stpc/pdfs/draft-scientific-integrity-policy-aug2011.pdf.

Unplanned gait termination in individuals with multiple sclerosis.

PubMed

Roeing, Kathleen L; Moon, Yaejin; Sosnoff, Jacob J

2017-03-01

Despite the pervasive nature of gait impairment in multiple sclerosis (MS), there is limited information concerning the control of gait termination in individuals with MS. The purpose of this investigation was to examine unplanned gait termination with and without cognitive distractors in individuals with MS compared to healthy controls. Thirty-one individuals with MS and 14 healthy controls completed a series of unplanned gait termination tasks over a pressure sensitive walkway under distracting and non-distracting conditions. Individuals with MS were further broken down into groups based on assistive device use: (no assistive device (MS noAD ) n=18; and assistive device (MS AD ) n=13). Individuals with MS who walked with an assistive device (MS AD : 67.8±15.1cm/s) walked slower than individuals without an assistive device (MS noAD : 110.4±32.3cm/s, p<0.01) and controls (120.0±30.0cm/s; p<0.01). There was a significant reduction in velocity in the cognitively distracting condition (93.4±32.1cm/s) compared to the normal condition [108.8±36.2cm/s; F(1,43)=3.4, p=0.04]. All participants took longer to stop during the distracting condition (1.7±0.6s) than the non-distracting condition (1.4±0.4s; U=673.0 p<0.01). After controlling for gait velocity, post-hoc analysis revealed the MS AD group took significantly longer to stop compared to the control group (p=0.05). Further research investigating the control of unplanned gait termination in MS is warranted. Copyright © 2017 Elsevier B.V. All rights reserved.

Texture Analysis and Cartographic Feature Extraction.

DTIC Science & Technology

1985-01-01

Investigations into using various image descriptors as well as developing interactive feature extraction software on the Digital Image Analysis Laboratory...system. Originator-supplied keywords: Ad-Hoc image descriptor; Bayes classifier; Bhattachryya distance; Clustering; Digital Image Analysis Laboratory

Crowdsourcing innovation at Caltrans.

DOT National Transportation Integrated Search

2016-09-19

This report documents the first year experience in launching and sustaining a web-based, crowdsourcing innovation management tool at the California Department of Transportation (Caltrans). In March 2015 an ad-hoc team of Caltrans managers and staff b...

Defining Requirements and Applying Information Modeling for Protecting Enterprise Assets

NASA Astrophysics Data System (ADS)

Fortier, Stephen C.; Volk, Jennifer H.

The advent of terrorist threats has heightened local, regional, and national governments' interest in emergency response and disaster preparedness. The threat of natural disasters also challenges emergency responders to act swiftly and in a coordinated fashion. When a disaster occurs, an ad hoc coalition of pre-planned groups usually forms to respond to the incident. History has shown that these “system of systems” do not interoperate very well. Communications between fire, police and rescue components either do not work or are inefficient. Government agencies, non-governmental organizations (NGOs), and private industry use a wide array of software platforms for managing data about emergency conditions, resources and response activities. Most of these are stand-alone systems with very limited capability for data sharing with other agencies or other levels of government. Information technology advances have facilitated the movement towards an integrated and coordinated approach to emergency management. Other communication mechanisms, such as video teleconferencing, digital television and radio broadcasting, are being utilized to combat the challenges of emergency information exchange. Recent disasters, such as Hurricane Katrina and the tsunami in Indonesia, have illuminated the weaknesses in emergency response. This paper will discuss the need for defining requirements for components of ad hoc coalitions which are formed to respond to disasters. A goal of our effort was to develop a proof of concept that applying information modeling to the business processes used to protect and mitigate potential loss of an enterprise was feasible. These activities would be modeled both pre- and post-incident.

Applying self-organizing map and modified radial based neural network for clustering and routing optimal path in wireless network

NASA Astrophysics Data System (ADS)

Hoomod, Haider K.; Kareem Jebur, Tuka

2018-05-01

Mobile ad hoc networks (MANETs) play a critical role in today’s wireless ad hoc network research and consist of active nodes that can be in motion freely. Because it consider very important problem in this network, we suggested proposed method based on modified radial basis function networks RBFN and Self-Organizing Map SOM. These networks can be improved by the use of clusters because of huge congestion in the whole network. In such a system, the performance of MANET is improved by splitting the whole network into various clusters using SOM. The performance of clustering is improved by the cluster head selection and number of clusters. Modified Radial Based Neural Network is very simple, adaptable and efficient method to increase the life time of nodes, packet delivery ratio and the throughput of the network will increase and connection become more useful because the optimal path has the best parameters from other paths including the best bitrate and best life link with minimum delays. Proposed routing algorithm depends on the group of factors and parameters to select the path between two points in the wireless network. The SOM clustering average time (1-10 msec for stall nodes) and (8-75 msec for mobile nodes). While the routing time range (92-510 msec).The proposed system is faster than the Dijkstra by 150-300%, and faster from the RBFNN (without modify) by 145-180%.

Categorial Compositionality II: Universal Constructions and a General Theory of (Quasi-)Systematicity in Human Cognition

PubMed Central

Phillips, Steven; Wilson, William H.

2011-01-01

A complete theory of cognitive architecture (i.e., the basic processes and modes of composition that together constitute cognitive behaviour) must explain the systematicity property—why our cognitive capacities are organized into particular groups of capacities, rather than some other, arbitrary collection. The classical account supposes: (1) syntactically compositional representations; and (2) processes that are sensitive to—compatible with—their structure. Classical compositionality, however, does not explain why these two components must be compatible; they are only compatible by the ad hoc assumption (convention) of employing the same mode of (concatenative) compositionality (e.g., prefix/postfix, where a relation symbol is always prepended/appended to the symbols for the related entities). Architectures employing mixed modes do not support systematicity. Recently, we proposed an alternative explanation without ad hoc assumptions, using category theory. Here, we extend our explanation to domains that are quasi-systematic (e.g., aspects of most languages), where the domain includes some but not all possible combinations of constituents. The central category-theoretic construct is an adjunction involving pullbacks, where the primary focus is on the relationship between processes modelled as functors, rather than the representations. A functor is a structure-preserving map (or construction, for our purposes). An adjunction guarantees that the only pairings of functors are the systematic ones. Thus, (quasi-)systematicity is a necessary consequence of a categorial cognitive architecture whose basic processes are functors that participate in adjunctions. PMID:21857816

Fluid Analysis of Network Content Dissemination and Cloud Systems

DTIC Science & Technology

2017-03-06

orchestration of multiple transfers , within the constraints of the communication substrate. In unstructured or aggressive environments where wireless ad...previous AFOSR/SOARD project, concerns peer-to-peer dissemination in wireless ad-hoc networks. We focus on the necessary tradeoff between an efficient...use of the network substrate, and the necessary reciprocity between peers, aspects that may be in conflict in the wireless setting. Our results

Fast incorporation of optical flow into active polygons.

PubMed

Unal, Gozde; Krim, Hamid; Yezzi, Anthony

2005-06-01

In this paper, we first reconsider, in a different light, the addition of a prediction step to active contour-based visual tracking using an optical flow and clarify the local computation of the latter along the boundaries of continuous active contours with appropriate regularizers. We subsequently detail our contribution of computing an optical flow-based prediction step directly from the parameters of an active polygon, and of exploiting it in object tracking. This is in contrast to an explicitly separate computation of the optical flow and its ad hoc application. It also provides an inherent regularization effect resulting from integrating measurements along polygon edges. As a result, we completely avoid the need of adding ad hoc regularizing terms to the optical flow computations, and the inevitably arbitrary associated weighting parameters. This direct integration of optical flow into the active polygon framework distinguishes this technique from most previous contour-based approaches, where regularization terms are theoretically, as well as practically, essential. The greater robustness and speed due to a reduced number of parameters of this technique are additional and appealing features.

Investigating Factorial Invariance of Latent Variables Across Populations When Manifest Variables Are Missing Completely

PubMed Central

Widaman, Keith F.; Grimm, Kevin J.; Early, Dawnté R.; Robins, Richard W.; Conger, Rand D.

2013-01-01

Difficulties arise in multiple-group evaluations of factorial invariance if particular manifest variables are missing completely in certain groups. Ad hoc analytic alternatives can be used in such situations (e.g., deleting manifest variables), but some common approaches, such as multiple imputation, are not viable. At least 3 solutions to this problem are viable: analyzing differing sets of variables across groups, using pattern mixture approaches, and a new method using random number generation. The latter solution, proposed in this article, is to generate pseudo-random normal deviates for all observations for manifest variables that are missing completely in a given sample and then to specify multiple-group models in a way that respects the random nature of these values. An empirical example is presented in detail comparing the 3 approaches. The proposed solution can enable quantitative comparisons at the latent variable level between groups using programs that require the same number of manifest variables in each group. PMID:24019738

Ad Hoc Influenza Vaccination During Years of Significant Antigenic Drift in a Tropical City With 2 Seasonal Peaks

PubMed Central

Wong, Martin C.S.; Nelson, E. Anthony S.; Leung, Czarina; Lee, Nelson; Chan, Martin C.W.; Choi, Kin Wing; Rainer, Timothy H.; Cheng, Frankie W.T.; Wong, Samuel Y.S.; Lai, Christopher K.C.; Lam, Bosco; Cheung, Tak Hong; Leung, Ting Fan; Chan, Paul K.S.

2016-01-01

Abstract We evaluated the acceptability of an additional ad hoc influenza vaccination among the health care professionals following seasons with significant antigenic drift. Self-administered, anonymous surveys were performed by hard copy questionnaires in public hospitals, and by an on-line platform available to all healthcare professionals, from April 1st to May 31st, 2015. A total of 1290 healthcare professionals completed the questionnaires, including doctors, nurses, and allied health professionals working in both the public and private systems. Only 31.8% of participating respondents expressed an intention to receive the additional vaccine, despite that the majority of them agreed or strongly agreed that it would bring benefit to the community (88.9%), save lives (86.7%), reduce medical expenses (76.3%), satisfy public expectation (82.8%), and increase awareness of vaccination (86.1%). However, a significant proportion expressed concern that the vaccine could disturb the normal immunization schedule (45.5%); felt uncertain what to do in the next vaccination round (66.0%); perceived that the summer peak might not occur (48.2%); and believed that the summer peak might not be of the same virus (83.5%). Furthermore, 27.8% of all respondents expected that the additional vaccination could weaken the efficacy of previous vaccinations; 51.3% was concerned about side effects; and 61.3% estimated that there would be a low uptake rate. If the supply of vaccine was limited, higher priority groups were considered to include the elderly aged ≥65 years with chronic medical conditions (89.2%), the elderly living in residential care homes (87.4%), and long-stay residents of institutions for the disabled (80.7%). The strongest factors associated with accepting the additional vaccine included immunization with influenza vaccines in the past 3 years, higher perceived risk of contracting influenza, and higher perceived severity of the disease impact. The acceptability to an additional ad hoc influenza vaccination was low among healthcare professionals. This could have a negative impact on such additional vaccination campaigns since healthcare professionals are a key driver for vaccine acceptance. The discordance in perceived risk and acceptance of vaccination regarding self versus public deserves further evaluation. PMID:27175633

Ad Hoc Influenza Vaccination During Years of Significant Antigenic Drift in a Tropical City With 2 Seasonal Peaks: A Cross-Sectional Survey Among Health Care Practitioners.

PubMed

Wong, Martin C S; Nelson, E Anthony S; Leung, Czarina; Lee, Nelson; Chan, Martin C W; Choi, Kin Wing; Rainer, Timothy H; Cheng, Frankie W T; Wong, Samuel Y S; Lai, Christopher K C; Lam, Bosco; Cheung, Tak Hong; Leung, Ting Fan; Chan, Paul K S

2016-05-01

We evaluated the acceptability of an additional ad hoc influenza vaccination among the health care professionals following seasons with significant antigenic drift.Self-administered, anonymous surveys were performed by hard copy questionnaires in public hospitals, and by an on-line platform available to all healthcare professionals, from April 1st to May 31st, 2015. A total of 1290 healthcare professionals completed the questionnaires, including doctors, nurses, and allied health professionals working in both the public and private systems.Only 31.8% of participating respondents expressed an intention to receive the additional vaccine, despite that the majority of them agreed or strongly agreed that it would bring benefit to the community (88.9%), save lives (86.7%), reduce medical expenses (76.3%), satisfy public expectation (82.8%), and increase awareness of vaccination (86.1%). However, a significant proportion expressed concern that the vaccine could disturb the normal immunization schedule (45.5%); felt uncertain what to do in the next vaccination round (66.0%); perceived that the summer peak might not occur (48.2%); and believed that the summer peak might not be of the same virus (83.5%). Furthermore, 27.8% of all respondents expected that the additional vaccination could weaken the efficacy of previous vaccinations; 51.3% was concerned about side effects; and 61.3% estimated that there would be a low uptake rate. If the supply of vaccine was limited, higher priority groups were considered to include the elderly aged ≥65 years with chronic medical conditions (89.2%), the elderly living in residential care homes (87.4%), and long-stay residents of institutions for the disabled (80.7%). The strongest factors associated with accepting the additional vaccine included immunization with influenza vaccines in the past 3 years, higher perceived risk of contracting influenza, and higher perceived severity of the disease impact.The acceptability to an additional ad hoc influenza vaccination was low among healthcare professionals. This could have a negative impact on such additional vaccination campaigns since healthcare professionals are a key driver for vaccine acceptance. The discordance in perceived risk and acceptance of vaccination regarding self versus public deserves further evaluation.

Critical review of expert system validation in transportation

DOT National Transportation Integrated Search

1997-01-01

Expert system validationthat is, testing systems to ascertain whether they achieve acceptable performance levelshas with few exceptions been ad hoc, informal, and of dubious value. Very few efforts have been made in this regard in the transport...

Effectiveness of AODV Protocol under Hidden Node Environment

NASA Astrophysics Data System (ADS)

Garg, Ruchi; Sharma, Himanshu; Kumar, Sumit

IEEE 802.11 is a standard for mobile ad hoc networks (MANET), implemented with various different protocols. Ad Hoc on Demand Distance Vector Routing (AODV) is one of the several protocols of IEEE 802.11, intended to provide various Quality of Service (QOS) parameters under acceptable range. To avoid the collision and interference the MAC protocol has only two solutions, one, to sense the physical carrier and second, to use the RTS/CTS handshake mechanism. But with the help of these methods AODV is not free from the problem of hidden nodes like other several protocols. Under the hidden node environment, performance of AODV depends upon various factors. The position of receiver and sender among the other nodes is very crucial and it affects the performance. Under the various situations the AODV is simulated with the help of NS2 and the outcomes are discussed.

Efficient Proximity Computation Techniques Using ZIP Code Data for Smart Cities †

PubMed Central

Murdani, Muhammad Harist; Hong, Bonghee

2018-01-01

In this paper, we are interested in computing ZIP code proximity from two perspectives, proximity between two ZIP codes (Ad-Hoc) and neighborhood proximity (Top-K). Such a computation can be used for ZIP code-based target marketing as one of the smart city applications. A naïve approach to this computation is the usage of the distance between ZIP codes. We redefine a distance metric combining the centroid distance with the intersecting road network between ZIP codes by using a weighted sum method. Furthermore, we prove that the results of our combined approach conform to the characteristics of distance measurement. We have proposed a general and heuristic approach for computing Ad-Hoc proximity, while for computing Top-K proximity, we have proposed a general approach only. Our experimental results indicate that our approaches are verifiable and effective in reducing the execution time and search space. PMID:29587366

Noise-Assisted Concurrent Multipath Traffic Distribution in Ad Hoc Networks

PubMed Central

Murata, Masayuki

2013-01-01

The concept of biologically inspired networking has been introduced to tackle unpredictable and unstable situations in computer networks, especially in wireless ad hoc networks where network conditions are continuously changing, resulting in the need of robustness and adaptability of control methods. Unfortunately, existing methods often rely heavily on the detailed knowledge of each network component and the preconfigured, that is, fine-tuned, parameters. In this paper, we utilize a new concept, called attractor perturbation (AP), which enables controlling the network performance using only end-to-end information. Based on AP, we propose a concurrent multipath traffic distribution method, which aims at lowering the average end-to-end delay by only adjusting the transmission rate on each path. We demonstrate through simulations that, by utilizing the attractor perturbation relationship, the proposed method achieves a lower average end-to-end delay compared to other methods which do not take fluctuations into account. PMID:24319375

Assessment of the 802.11g Wireless Protocol for Lunar Surface Communications

NASA Technical Reports Server (NTRS)

Chelmins, David T.; Bguyen, Hung D.; Foore, Lawrence R.

2009-01-01

Future lunar surface missions supporting the NASA Vision for Space Exploration will rely on wireless networks to transmit voice and data. The ad hoc network architecture is of particular interest since it does not require a complex infrastructure. In this report, we looked at data performance over an ad hoc network with varying distances between Apple AirPort wireless cards. We developed a testing program to transmit data packets at precise times and then monitored the receive time to characterize connection delay, packet loss, and data rate. Best results were received for wireless links of less than 75 ft, and marginally acceptable (25-percent) packet loss was received at 150 ft. It is likely that better results will be obtained on the lunar surface because of reduced radiofrequency interference; however, higher power transmitters or receivers will be needed for significant performance gains.

Impact of Beamforming on the Path Connectivity in Cognitive Radio Ad Hoc Networks

PubMed Central

Dung, Le The; Hieu, Tran Dinh; Choi, Seong-Gon; Kim, Byung-Seo; An, Beongku

2017-01-01

This paper investigates the impact of using directional antennas and beamforming schemes on the connectivity of cognitive radio ad hoc networks (CRAHNs). Specifically, considering that secondary users use two kinds of directional antennas, i.e., uniform linear array (ULA) and uniform circular array (UCA) antennas, and two different beamforming schemes, i.e., randomized beamforming and center-directed to communicate with each other, we study the connectivity of all combination pairs of directional antennas and beamforming schemes and compare their performances to those of omnidirectional antennas. The results obtained in this paper show that, compared with omnidirectional transmission, beamforming transmission only benefits the connectivity when the density of secondary user is moderate. Moreover, the combination of UCA and randomized beamforming scheme gives the highest path connectivity in all evaluating scenarios. Finally, the number of antenna elements and degree of path loss greatly affect path connectivity in CRAHNs. PMID:28346377

Ad hoc committee on global climate issues: Annual report

USGS Publications Warehouse

Gerhard, L.C.; Hanson, B.M.B.

2000-01-01

The AAPG Ad Hoc Committee on Global Climate Issues has studied the supposition of human-induced climate change since the committee's inception in January 1998. This paper details the progress and findings of the committee through June 1999. At that time there had been essentially no geologic input into the global climate change debate. The following statements reflect the current state of climate knowledge from the geologic perspective as interpreted by the majority of the committee membership. The committee recognizes that new data could change its conclusions. The earth's climate is constantly changing owing to natural variability in earth processes. Natural climate variability over recent geological time is greater than reasonable estimates of potential human-induced greenhouse gas changes. Because no tool is available to test the supposition of human-induced climate change and the range of natural variability is so great, there is no discernible human influence on global climate at this time.

An advanced search engine for patent analytics in medicinal chemistry.

PubMed

Pasche, Emilie; Gobeill, Julien; Teodoro, Douglas; Gaudinat, Arnaud; Vishnykova, Dina; Lovis, Christian; Ruch, Patrick

2012-01-01

Patent collections contain an important amount of medical-related knowledge, but existing tools were reported to lack of useful functionalities. We present here the development of TWINC, an advanced search engine dedicated to patent retrieval in the domain of health and life sciences. Our tool embeds two search modes: an ad hoc search to retrieve relevant patents given a short query and a related patent search to retrieve similar patents given a patent. Both search modes rely on tuning experiments performed during several patent retrieval competitions. Moreover, TWINC is enhanced with interactive modules, such as chemical query expansion, which is of prior importance to cope with various ways of naming biomedical entities. While the related patent search showed promising performances, the ad-hoc search resulted in fairly contrasted results. Nonetheless, TWINC performed well during the Chemathlon task of the PatOlympics competition and experts appreciated its usability.

A User Authentication Scheme Based on Elliptic Curves Cryptography for Wireless Ad Hoc Networks

PubMed Central

Chen, Huifang; Ge, Linlin; Xie, Lei

2015-01-01

The feature of non-infrastructure support in a wireless ad hoc network (WANET) makes it suffer from various attacks. Moreover, user authentication is the first safety barrier in a network. A mutual trust is achieved by a protocol which enables communicating parties to authenticate each other at the same time and to exchange session keys. For the resource-constrained WANET, an efficient and lightweight user authentication scheme is necessary. In this paper, we propose a user authentication scheme based on the self-certified public key system and elliptic curves cryptography for a WANET. Using the proposed scheme, an efficient two-way user authentication and secure session key agreement can be achieved. Security analysis shows that our proposed scheme is resilient to common known attacks. In addition, the performance analysis shows that our proposed scheme performs similar or better compared with some existing user authentication schemes. PMID:26184224

A User Authentication Scheme Based on Elliptic Curves Cryptography for Wireless Ad Hoc Networks.

PubMed

Chen, Huifang; Ge, Linlin; Xie, Lei

2015-07-14

The feature of non-infrastructure support in a wireless ad hoc network (WANET) makes it suffer from various attacks. Moreover, user authentication is the first safety barrier in a network. A mutual trust is achieved by a protocol which enables communicating parties to authenticate each other at the same time and to exchange session keys. For the resource-constrained WANET, an efficient and lightweight user authentication scheme is necessary. In this paper, we propose a user authentication scheme based on the self-certified public key system and elliptic curves cryptography for a WANET. Using the proposed scheme, an efficient two-way user authentication and secure session key agreement can be achieved. Security analysis shows that our proposed scheme is resilient to common known attacks. In addition, the performance analysis shows that our proposed scheme performs similar or better compared with some existing user authentication schemes.

Space Station Engineering and Technology Development: Proceedings of the Panel on In-Space Engineering Research and Technology Development

NASA Technical Reports Server (NTRS)

1985-01-01

In 1984 the ad hoc committee on Space Station Engineering and Technology Development of the Aeronautics and Space Engineering Board (ASEB) conducted a review of the National Aeronautics and Space Administration's (NASA's) space station program planning. The review addressed the initial operating configuration (IOC) of the station. The ASEB has reconstituted the ad hoc committee which then established panels to address each specific related subject. The participants of the panels come from the committee, industry, and universities. The proceedings of the Panel on In Space Engineering Research and Technology Development are presented in this report. Activities, and plans for identifying and developing R&T programs to be conducted by the space station and related in space support needs including module requirements are addressed. Consideration is given to use of the station for R&T for other government agencies, universities, and industry.

Some new ideas for the study of the complex spectral line profiles of hot emission stars and quasars

NASA Astrophysics Data System (ADS)

Danezis, E.

2013-01-01

Some Hot Emission Stars and AGNs present peculiar spectral line profiles which are due to DACs and SACs phenomena. The origin and the mechanisms which are responsible for the creation of DACs/SACs is an important problem that has been studied by many researchers. This paper is a review of our efforts to study the origin and the mechanisms of these phenomena. At first we present a theoretic ad hoc picture for the structure of the plasma that surrounds the specific category of hot emission stars that present DACs or SACs. Then we present the mathematical model that we constructed, which is based on the properties of the above ad hoc theoretical structure. Finally, we present some results from our statistical studies that prove the consistency of our model with the classical physical theory.

Software Architecture of Sensor Data Distribution In Planetary Exploration

NASA Technical Reports Server (NTRS)

Lee, Charles; Alena, Richard; Stone, Thom; Ossenfort, John; Walker, Ed; Notario, Hugo

2006-01-01

Data from mobile and stationary sensors will be vital in planetary surface exploration. The distribution and collection of sensor data in an ad-hoc wireless network presents a challenge. Irregular terrain, mobile nodes, new associations with access points and repeaters with stronger signals as the network reconfigures to adapt to new conditions, signal fade and hardware failures can cause: a) Data errors; b) Out of sequence packets; c) Duplicate packets; and d) Drop out periods (when node is not connected). To mitigate the effects of these impairments, a robust and reliable software architecture must be implemented. This architecture must also be tolerant of communications outages. This paper describes such a robust and reliable software infrastructure that meets the challenges of a distributed ad hoc network in a difficult environment and presents the results of actual field experiments testing the principles and actual code developed.

Wikisearching and Wikilinking

NASA Astrophysics Data System (ADS)

Jenkinson, Dylan; Leung, Kai-Cheung; Trotman, Andrew

The University of Otago submitted three element runs and three passage runs to the Relevance-in-Context task of the ad hoc track. The best Otago run was a whole-document run placing 7th. The best Otago passage run placed 13th while the best Otago element run placed 31st. There were a total of 40 runs submitted to the task. The ad hoc result reinforced our prior belief that passages are better answers than elements and that the most important aspect of the focused retrieval is the identification of relevant documents. Six runs were submitted to the Link-the-Wiki track. The best Otago run placed 1st (of 21) in file to file automatic assessment and 6th (of 28) with manual assessment. The Itakura & Clarke algorithm was used for outgoing links, with special attention paid to parsing and case sensitivity. For incoming links representative terms were selected from the document and used to find similar documents.

A critical examination of community-based responses to household food insecurity in Canada.

PubMed

Tarasuk, V

2001-08-01

Over the past two decades, household food insecurity has emerged as a significant social problem and serious public health concern in the "First World." In Canada, communities initially responded by establishing ad hoc charitable food assistance programs, but the programs have become institutionalized. In the quest for more appropriate and effective responses, a variety of community development programs have recently been initiated. Some are designed to foster personal empowerment through self-help and mutual support; others promote community-level strategies to strengthen local control over food production. The capacity of current initiatives to improve household food security appears limited by their inability to overcome or alter the poverty that under-pins this problem. This may relate to the continued focus on food-based responses, the ad hoc and community-based nature of the initiatives, and their origins in publicly funded health and social service sectors.

Real-Time Support on IEEE 802.11 Wireless Ad-Hoc Networks: Reality vs. Theory

NASA Astrophysics Data System (ADS)

Kang, Mikyung; Kang, Dong-In; Suh, Jinwoo

The usable throughput of an IEEE 802.11 system for an application is much less than the raw bandwidth. Although 802.11b has a theoretical maximum of 11Mbps, more than half of the bandwidth is consumed by overhead leaving at most 5Mbps of usable bandwidth. Considering this characteristic, this paper proposes and analyzes a real-time distributed scheduling scheme based on the existing IEEE 802.11 wireless ad-hoc networks, using USC/ISI's Power Aware Sensing Tracking and Analysis (PASTA) hardware platform. We compared the distributed real-time scheduling scheme with the real-time polling scheme to meet deadline, and compared a measured real bandwidth with a theoretical result. The theoretical and experimental results show that the distributed scheduling scheme can guarantee real-time traffic and enhances the performance up to 74% compared with polling scheme.

Context dependent off loading for cloudlet in mobile ad-hoc network

NASA Astrophysics Data System (ADS)

Bhatt, N.; Nadesh, R. K.; ArivuSelvan, K.

2017-11-01

Cloud Computing in Mobile Ad-hoc network is emerging part of research consideration as the demand and competency of mobile devices increased in last few years. To follow out operation within the remote cloud builds the postponement and influences the administration standard. To keep away from this trouble cloudlet is presented. Cloudlet gives identical support of the devices as cloud at low inactivity however at high transfer speed. Be that as it may, choice of a cloudlet for offloading calculation with flat energy is a noteworthy test if multiple cloud let is accessible adjacent. Here I proposed energy and bandwidth (Traffic overload for communication with cloud) aware cloudlet selection strategy based on the context dependency of the device location. It works on the basis of mobile device location and bandwidth availability of cloudlet. The cloudlet offloading and selection process using given solution is simulated in Cloud ~ Simulator.

Efficient Proximity Computation Techniques Using ZIP Code Data for Smart Cities †.

PubMed

Murdani, Muhammad Harist; Kwon, Joonho; Choi, Yoon-Ho; Hong, Bonghee

2018-03-24

In this paper, we are interested in computing ZIP code proximity from two perspectives, proximity between two ZIP codes ( Ad-Hoc ) and neighborhood proximity ( Top-K ). Such a computation can be used for ZIP code-based target marketing as one of the smart city applications. A naïve approach to this computation is the usage of the distance between ZIP codes. We redefine a distance metric combining the centroid distance with the intersecting road network between ZIP codes by using a weighted sum method. Furthermore, we prove that the results of our combined approach conform to the characteristics of distance measurement. We have proposed a general and heuristic approach for computing Ad-Hoc proximity, while for computing Top-K proximity, we have proposed a general approach only. Our experimental results indicate that our approaches are verifiable and effective in reducing the execution time and search space.

An epidemic model for biological data fusion in ad hoc sensor networks

NASA Astrophysics Data System (ADS)

Chang, K. C.; Kotari, Vikas

2009-05-01

Bio terrorism can be a very refined and a catastrophic approach of attacking a nation. This requires the development of a complete architecture dedicatedly designed for this purpose which includes but is not limited to Sensing/Detection, Tracking and Fusion, Communication, and others. In this paper we focus on one such architecture and evaluate its performance. Various sensors for this specific purpose have been studied. The accent has been on use of Distributed systems such as ad-hoc networks and on application of epidemic data fusion algorithms to better manage the bio threat data. The emphasis has been on understanding the performance characteristics of these algorithms under diversified real time scenarios which are implemented through extensive JAVA based simulations. Through comparative studies on communication and fusion the performance of channel filter algorithm for the purpose of biological sensor data fusion are validated.

Relationship between Omnibus and Post-hoc Tests: An Investigation of performance of the F test in ANOVA.

PubMed

Chen, Tian; Xu, Manfei; Tu, Justin; Wang, Hongyue; Niu, Xiaohui

2018-02-25

Comparison of groups is a common statistical test in many biomedical and psychosocial research studies. When there are more than two groups, one first performs an omnibus test for an overall difference across the groups. If this null is rejected, one then proceeds to the next step of post-hoc pairwise group comparisons to determine sources of difference. Otherwise, one stops and declares no group difference. A common belief is that if the omnibus test is significant, there must exist at least two groups that are significantly different and vice versa. Thus, when the omnibus test is significant, but no post-hoc between-group comparison shows significant difference, one is bewildered at what is going on and wondering how to interpret the results. At the end of the spectrum, when the omnibus test is not significant, one wonders if all post-hoc tests will be non-significant as well so that stopping after a nonsignificant omnibus test will not lead to any missed opportunity of finding group difference. In this report, we investigate this perplexing phenomenon and discuss how to interpret such results.

Role of the α1 Blocker Doxazosin in Alcoholism: a Proof-of-Concept Randomized Controlled Trial

PubMed Central

Kenna, George A.; Haass-Koffler, Carolina L.; Zywiak, William H.; Edwards, Steven M.; Brickley, Michael B.; Swift, Robert M.; Leggio, Lorenzo

2015-01-01

Background Evidence suggests the norepinephrine system represents an important treatment target for alcohol dependence (AD) and the α1-blocker prazosin may reduce alcohol drinking in rodents and alcoholic patients. The α1-blocker doxazosin demonstrates a more favorable pharmacokinetic profile than prazosin but has never been studied for AD. Methods A double-blind placebo-controlled randomized clinical trial was conducted in AD individuals seeking outpatient treatment. Doxazosin or matched placebo was titrated to 16-mg/day (or maximum tolerable dose). Drinks per week (DPW) and heavy drinking days (HDD) per week were primary outcomes. Family history density of alcoholism (FHDA), severity of AD, and gender were a priori moderators. Results Forty-one AD individuals were randomized, 30 (doxazosin = 15) completed the treatment phase, and 28 (doxazosin = 14) also completed the follow-up. There were no significant differences between groups on DPW and HDD per week. With FHDA as a moderator, there were significant FHDA x medication interactions for both DPW [pcorrected = .001, d = 1.18] and HDD [pcorrected = .00009, d = 1.30]. Post-hoc analyses revealed that doxazosin significantly reduced alcohol drinking in AD patients with high FHDA and by contrast increased drinking in those with low FHDA. Conclusions Doxazosin may be effective selectively in AD patients with high FHDA. This study provides preliminary evidence for personalized medicine using α1-blockade to treat AD. However, confirmatory studies are required. PMID:26037245

The effects of counseling spouse caregivers of people with Alzheimer disease taking donepezil and of country of residence on rates of admission to nursing homes and mortality.

PubMed

Brodaty, Henry; Mittelman, Mary; Gibson, Louisa; Seeher, Katrin; Burns, Alistair

2009-09-01

Does psychosocial intervention for caregivers whose spouses with Alzheimer disease (AD) are taking donepezil delay nursing home (NH) placement or death of patients? Randomized controlled trial with 2 years of active treatment and up to 8.5 years of follow-up (mean: 5.4 years, SD: 2.4). Outpatients of research clinics in Australia, the United Kingdom, and the United States. One hundred and fifty-five persons with AD and their spouses. Five sessions of individual and family counseling (+ prn ad hoc counseling) or usual care. Time to institutionalization and death using Cox proportional hazards methods. Over a mean of 5.4 years (SD: 2.4), there were no differences in NH placement or mortality by intervention group, but there were by country, with Australian patients admitted to NHs earlier than U.S. than U.K. patients. Earlier NH admission of Australian compared to U.K. and U.S. subjects may be due to differences in health care, NH systems, availability, and affordability.

Zinc Finger Transcription Factors as Novel Genetic Switches to Modulate Metastatic Progression of Breast Tumors

DTIC Science & Technology

2008-05-01

critical level of significance set up at P < 0.05, and significant differences between groups of treatments were analyzed with post hoc Turkish test ...2008 differences between groups of treatments were analyzed with post hoc Turkish test . As shown in Fig. 2A, particular ATFs synergized with chromatin...using ANOVA test and the post hoc Turkish test ; critical level of significance was set up at P < 0.05. B, real- time expression analysis of maspin mRNA

[The global harmonization task force : successes and challenges].

PubMed

Rotter, R G

2009-06-01

With the move towards globalized international commerce and trade, a call for harmonization of medical device regulatory requirements and practices has evolved. The purpose of the Global Harmonization Task Force (GHTF) is to encourage convergence of regulatory requirements and practices at a global level through consensus to achieve four principle goals: promote safety, quality and performance/effectiveness of medical devices; encourage technological innovation; foster international trade; and serve as a forum of information exchange - all in the interests of protecting and promoting public health. The GHTF is governed by a Steering Committee, and the principle development of the GHTF regulatory model has been, and continues to be, done through five working groups known as Study Groups and supplemented recently by the creation of several Ad Hoc Working Groups. Since its creation in 1992, the members of the GHTF have worked collaboratively to develop what is now ready to be called a global model for the regulation of medical devices.

Making great leaps forward: Accounting for detectability in herpetological field studies

USGS Publications Warehouse

Mazerolle, Marc J.; Bailey, Larissa L.; Kendall, William L.; Royle, J. Andrew; Converse, Sarah J.; Nichols, James D.

2007-01-01

Detecting individuals of amphibian and reptile species can be a daunting task. Detection can be hindered by various factors such as cryptic behavior, color patterns, or observer experience. These factors complicate the estimation of state variables of interest (e.g., abundance, occupancy, species richness) as well as the vital rates that induce changes in these state variables (e.g., survival probabilities for abundance; extinction probabilities for occupancy). Although ad hoc methods (e.g., counts uncorrected for detection, return rates) typically perform poorly in the face of no detection, they continue to be used extensively in various fields, including herpetology. However, formal approaches that estimate and account for the probability of detection, such as capture-mark-recapture (CMR) methods and distance sampling, are available. In this paper, we present classical approaches and recent advances in methods accounting for detectability that are particularly pertinent for herpetological data sets. Through examples, we illustrate the use of several methods, discuss their performance compared to that of ad hoc methods, and we suggest available software to perform these analyses. The methods we discuss control for imperfect detection and reduce bias in estimates of demographic parameters such as population size, survival, or, at other levels of biological organization, species occurrence. Among these methods, recently developed approaches that no longer require marked or resighted individuals should be particularly of interest to field herpetologists. We hope that our effort will encourage practitioners to implement some of the estimation methods presented herein instead of relying on ad hoc methods that make more limiting assumptions.

On using multiple routing metrics with destination sequenced distance vector protocol for MultiHop wireless ad hoc networks

NASA Astrophysics Data System (ADS)

Mehic, M.; Fazio, P.; Voznak, M.; Partila, P.; Komosny, D.; Tovarek, J.; Chmelikova, Z.

2016-05-01

A mobile ad hoc network is a collection of mobile nodes which communicate without a fixed backbone or centralized infrastructure. Due to the frequent mobility of nodes, routes connecting two distant nodes may change. Therefore, it is not possible to establish a priori fixed paths for message delivery through the network. Because of its importance, routing is the most studied problem in mobile ad hoc networks. In addition, if the Quality of Service (QoS) is demanded, one must guarantee the QoS not only over a single hop but over an entire wireless multi-hop path which may not be a trivial task. In turns, this requires the propagation of QoS information within the network. The key to the support of QoS reporting is QoS routing, which provides path QoS information at each source. To support QoS for real-time traffic one needs to know not only minimum delay on the path to the destination but also the bandwidth available on it. Therefore, throughput, end-to-end delay, and routing overhead are traditional performance metrics used to evaluate the performance of routing protocol. To obtain additional information about the link, most of quality-link metrics are based on calculation of the lost probabilities of links by broadcasting probe packets. In this paper, we address the problem of including multiple routing metrics in existing routing packets that are broadcasted through the network. We evaluate the efficiency of such approach with modified version of DSDV routing protocols in ns-3 simulator.

Predicting impact of multi-paths on phase change in map-based vehicular ad hoc networks

NASA Astrophysics Data System (ADS)

Rahmes, Mark; Lemieux, George; Sonnenberg, Jerome; Chester, David B.

2014-05-01

Dynamic Spectrum Access, which through its ability to adapt the operating frequency of a radio, is widely believed to be a solution to the limited spectrum problem. Mobile Ad Hoc Networks (MANETs) can extend high capacity mobile communications over large areas where fixed and tethered-mobile systems are not available. In one use case with high potential impact cognitive radio employs spectrum sensing to facilitate identification of allocated frequencies not currently accessed by their primary users. Primary users own the rights to radiate at a specific frequency and geographic location, secondary users opportunistically attempt to radiate at a specific frequency when the primary user is not using it. We quantify optimal signal detection in map based cognitive radio networks with multiple rapidly varying phase changes and multiple orthogonal signals. Doppler shift occurs due to reflection, scattering, and rapid vehicle movement. Path propagation as well as vehicle movement produces either constructive or destructive interference with the incident wave. Our signal detection algorithms can assist the Doppler spread compensation algorithm by deciding how many phase changes in signals are present in a selected band of interest. Additionally we can populate a spatial radio environment map (REM) database with known information that can be leveraged in an ad hoc network to facilitate Dynamic Spectrum Access. We show how topography can help predict the impact of multi-paths on phase change, as well as about the prediction from dense traffic areas. Utilization of high resolution geospatial data layers in RF propagation analysis is directly applicable.

3VSR: Three Valued Secure Routing for Vehicular Ad Hoc Networks using Sensing Logic in Adversarial Environment

PubMed Central

Wang, Liangmin

2018-01-01

Today IoT integrate thousands of inter networks and sensing devices e.g., vehicular networks, which are considered to be challenging due to its high speed and network dynamics. The goal of future vehicular networks is to improve road safety, promote commercial or infotainment products and to reduce the traffic accidents. All these applications are based on the information exchange among nodes, so not only reliable data delivery but also the authenticity and credibility of the data itself are prerequisite. To cope with the aforementioned problem, trust management come up as promising candidate to conduct node’s transaction and interaction management, which requires distributed mobile nodes cooperation for achieving design goals. In this paper, we propose a trust-based routing protocol i.e., 3VSR (Three Valued Secure Routing), which extends the widely used AODV (Ad hoc On-demand Distance Vector) routing protocol and employs the idea of Sensing Logic-based trust model to enhance the security solution of VANET (Vehicular Ad-Hoc Network). The existing routing protocol are mostly based on key or signature-based schemes, which off course increases computation overhead. In our proposed 3VSR, trust among entities is updated frequently by means of opinion derived from sensing logic due to vehicles random topologies. In 3VSR the theoretical capabilities are based on Dirichlet distribution by considering prior and posterior uncertainty of the said event. Also by using trust recommendation message exchange, nodes are able to reduce computation and routing overhead. The simulated results shows that the proposed scheme is secure and practical. PMID:29538314

3VSR: Three Valued Secure Routing for Vehicular Ad Hoc Networks using Sensing Logic in Adversarial Environment.

PubMed

Sohail, Muhammad; Wang, Liangmin

2018-03-14

Today IoT integrate thousands of inter networks and sensing devices e.g., vehicular networks, which are considered to be challenging due to its high speed and network dynamics. The goal of future vehicular networks is to improve road safety, promote commercial or infotainment products and to reduce the traffic accidents. All these applications are based on the information exchange among nodes, so not only reliable data delivery but also the authenticity and credibility of the data itself are prerequisite. To cope with the aforementioned problem, trust management come up as promising candidate to conduct node's transaction and interaction management, which requires distributed mobile nodes cooperation for achieving design goals. In this paper, we propose a trust-based routing protocol i.e., 3VSR (Three Valued Secure Routing), which extends the widely used AODV (Ad hoc On-demand Distance Vector) routing protocol and employs the idea of Sensing Logic-based trust model to enhance the security solution of VANET (Vehicular Ad-Hoc Network). The existing routing protocol are mostly based on key or signature-based schemes, which off course increases computation overhead. In our proposed 3VSR, trust among entities is updated frequently by means of opinion derived from sensing logic due to vehicles random topologies. In 3VSR the theoretical capabilities are based on Dirichlet distribution by considering prior and posterior uncertainty of the said event. Also by using trust recommendation message exchange, nodes are able to reduce computation and routing overhead. The simulated results shows that the proposed scheme is secure and practical.

An official American Thoracic Society workshop report: assessment and palliative management of dyspnea crisis.

PubMed

Mularski, Richard A; Reinke, Lynn F; Carrieri-Kohlman, Virginia; Fischer, Mark D; Campbell, Margaret L; Rocker, Graeme; Schneidman, Ann; Jacobs, Susan S; Arnold, Robert; Benditt, Joshua O; Booth, Sara; Byock, Ira; Chan, Garrett K; Curtis, J Randall; Donesky, Doranne; Hansen-Flaschen, John; Heffner, John; Klein, Russell; Limberg, Trina M; Manning, Harold L; Morrison, R Sean; Ries, Andrew L; Schmidt, Gregory A; Selecky, Paul A; Truog, Robert D; Wang, Angela C C; White, Douglas B

2013-10-01

In 2009, the American Thoracic Society (ATS) funded an assembly project, Palliative Management of Dyspnea Crisis, to focus on identification, management, and optimal resource utilization for effective palliation of acute episodes of dyspnea. We conducted a comprehensive search of the medical literature and evaluated available evidence from systematic evidence-based reviews (SEBRs) using a modified AMSTAR approach and then summarized the palliative management knowledge base for participants to use in discourse at a 2009 ATS workshop. We used an informal consensus process to develop a working definition of this novel entity and established an Ad Hoc Committee on Palliative Management of Dyspnea Crisis to further develop an official ATS document on the topic. The Ad Hoc Committee members defined dyspnea crisis as "sustained and severe resting breathing discomfort that occurs in patients with advanced, often life-limiting illness and overwhelms the patient and caregivers' ability to achieve symptom relief." Dyspnea crisis can occur suddenly and is characteristically without a reversible etiology. The workshop participants focused on dyspnea crisis management for patients in whom the goals of care are focused on palliation and for whom endotracheal intubation and mechanical ventilation are not consistent with articulated preferences. However, approaches to dyspnea crisis may also be appropriate for patients electing life-sustaining treatment. The Ad Hoc Committee developed a Workshop Report concerning assessment of dyspnea crisis; ethical and professional considerations; efficient utilization, communication, and care coordination; clinical management of dyspnea crisis; development of patient education and provider aid products; and enhancing implementation with audit and quality improvement.

First-order and higher order sequence learning in specific language impairment.

PubMed

Clark, Gillian M; Lum, Jarrad A G

2017-02-01

A core claim of the procedural deficit hypothesis of specific language impairment (SLI) is that the disorder is associated with poor implicit sequence learning. This study investigated whether implicit sequence learning problems in SLI are present for first-order conditional (FOC) and higher order conditional (HOC) sequences. Twenty-five children with SLI and 27 age-matched, nonlanguage-impaired children completed 2 serial reaction time tasks. On 1 version, the sequence to be implicitly learnt comprised a FOC sequence and on the other a HOC sequence. Results showed that the SLI group learned the HOC sequence (η p ² = .285, p = .005) but not the FOC sequence (η p ² = .099, p = .118). The control group learned both sequences (FOC η p ² = .497, HOC η p 2= .465, ps < .001). The SLI group's difficulty learning the FOC sequence is consistent with the procedural deficit hypothesis. However, the study provides new evidence that multiple mechanisms may underpin the learning of FOC and HOC sequences. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Boarding Team Networking on the Move: Applying Unattended Relay Nodes

DTIC Science & Technology

2014-09-01

below the main deck via a wireless ad-hoc network will enhance the situational awareness. Regarding the boarding of a non-compliant vessel, tracking...reaction time. 14. SUBJECT TERMS Maritime Interdiction Operations, Boarding Team Networking , Unattended Relay Nodes, Wireless Mesh Networks Onboard...the steel structures of naval vessels obstruct signals to propagate below the main deck. Extending the network below the main deck via a wireless ad

AD Hoc Study on Human Robot Interface Issues

DTIC Science & Technology

2002-09-01

of joint range of motion limits on strength. When the angle of a fully deflected aircraft rudder/ brake pedal is beyond the limit of ankle...mobility, the pedal will seem to have excessive resistance. In addition, this will prevent the pilot from fully utilizing the brakes of the aircraft...importance and value added of HE efforts. 34 Center High-Mounted Brake Lights. In 1985, after extensive HE studies showing positive

A Family of ACO Routing Protocols for Mobile Ad Hoc Networks.

PubMed

Rupérez Cañas, Delfín; Sandoval Orozco, Ana Lucila; García Villalba, Luis Javier; Kim, Tai-Hoon

2017-05-22

In this work, an ACO routing protocol for mobile ad hoc networks based on AntHocNet is specified. As its predecessor, this new protocol, called AntOR, is hybrid in the sense that it contains elements from both reactive and proactive routing. Specifically, it combines a reactive route setup process with a proactive route maintenance and improvement process. Key aspects of the AntOR protocol are the disjoint-link and disjoint-node routes, separation between the regular pheromone and the virtual pheromone in the diffusion process and the exploration of routes, taking into consideration the number of hops in the best routes. In this work, a family of ACO routing protocols based on AntOR is also specified. These protocols are based on protocol successive refinements. In this work, we also present a parallelized version of AntOR that we call PAntOR. Using programming multiprocessor architectures based on the shared memory protocol, PAntOR allows running tasks in parallel using threads. This parallelization is applicable in the route setup phase, route local repair process and link failure notification. In addition, a variant of PAntOR that consists of having more than one interface, which we call PAntOR-MI (PAntOR-Multiple Interface), is specified. This approach parallelizes the sending of broadcast messages by interface through threads.

Mathematics, Information, and Life Sciences

DTIC Science & Technology

2012-03-05

INS • Chip -scale atomic clocks • Ad hoc networks • Polymorphic networks • Agile networks • Laser communications • Frequency-agile RF systems...FY12 BAA Bionavigation (Bio) Neuromorphic Computing (Human) Multi-scale Modeling (Math) Foundations of Information Systems (Info) BRI

Magnetic Mars Dust Removal Technology

NASA Astrophysics Data System (ADS)

Arias, F. J.; De las Heras, S. A.

2018-04-01

From the recorded data from recent Mars missions, there are substantial evidence that the dust of Mars is strongly magnetic. In this work we propose a novel, reliable, robust, and ad hoc technique for Mars dust removal for Mars Sample Return mission.

SAIDO learning as a cognitive intervention for dementia care: a preliminary study.

PubMed

Kawashima, Ryuta; Hiller, Deborah Lewis; Sereda, Sheryl L; Antonczak, Michelle; Serger, Kara; Gannon, Denise; Ito, Shinji; Otake, Hiroshi; Yunomae, Daisaku; Kobayashi, Akihito; Muller, Christopher; Murata, Hiroyuki; FallCreek, Stephanie

2015-01-01

The purpose of this study was to examine the beneficial effects on cognitive function by a cognitive intervention program designed for dementia care called Learning Therapy in Japan and SAIDO Learning in the United States (hereinafter "SAIDO Learning," as appropriate). SAIDO Learning is a working memory training program that uses systematized basic problems in arithmetic and language, including reading aloud, as well as writing. Twenty-three nursing home residents with dementia were assigned as an intervention group, and another 24 people with dementia at another nursing home were assigned as a control group. Both nursing homes were operated by the same organization, and residents of both nursing homes received essentially the same nursing care. Thirteen and 6 subjects of the intervention and control groups, respectively, were clinically diagnosed as Alzheimer disease (AD). After the 6-month intervention, the participants with AD of the intervention group showed statistically significant improvement in cognitive function, as measured by the Mini-Mental State Examination (MMSE) compared with the control participants. In addition, post hoc analysis revealed that the Frontal Assessment Battery at Bedside (FAB) scores of the intervention group tended to improve after 6-month intervention. Based on MDS scores, improvements in total mood severity scores also were observed, but only in the intervention group of the participants with AD. These results suggest that SAIDO Learning is an effective cognitive intervention and is useful for dementia care. An additional outcome of this intervention, which has not yet been evaluated in detail, appears to be that it promotes greater positive engagement of a diversity of nursing home staff in the residents' individual progress and care needs. Copyright © 2015 AMDA – The Society for Post-Acute and Long-Term Care Medicine. Published by Elsevier Inc. All rights reserved.

Probiotics improve insulin resistance status in an experimental model of Alzheimer's disease.

PubMed

Athari Nik Azm, Somayeh; Djazayeri, Abolghassem; Safa, Majid; Azami, Kian; Djalali, Mahmoud; Sharifzadeh, Mohammad; Vafa, Mohammadreza

2017-01-01

Background: Nowadays, Alzheimer's disease (AD) is considered as Type 3 diabetes in which insulin resistance is the common cause of both diseases. Disruption of insulin signaling cascade and insulin resistance can induce AD; and central insulin resistance causes systemic alterations in serum insulin, FBS levels, and lipid profile. Studies have shown that probiotics ( Lactobacillus and Bifidobacterium species) can be used as a nutritional approach to improve these metabolic changes. We assessed the probiotic effect (4 species of Lactobacillus and Bifidobacterium ) on insulin resistance biomarkers in an experimental model of AD. Methods: A total of 60 rats were divided into 5 groups: (1) a control group without surgical and dietary intervention; (2) a controlprobiotics group receiving probiotics for 8 weeks, but not receiving any surgical intervention; (3) a group receiving a sham operation in which PBS was injected intrahippocampus but without dietary intervention; (4) an Alzheimer group for which Amyloid-ß (Aß) 1- 42 was injected intrahippocampus but without dietary intervention; (5) and an Alzheimer-probiotics group for which Aß1-42 was injected intrahippocampus and given 2g probiotics for 8 weeks. The FBS levels and lipid profile were measured by a calorimetric method, insulin levels were detected by an ELISA kit, and HOMA-IR was calculated using a formula. ANOVA (one way analysis of variance followed by Bonferroni comparisons post hoc) was used to compare all the variables between groups. Results: Serum glucose, insulin levels, and HOMA-IR index increased in the Alzheimer group compared to the control (p<0.001), while probiotics decreased only insulin level and HOMA-IR index in AP group compared to Alzheimer group (p<0.001). Also, TG levels increased in the Alzheimer group (p<0.001), but no significant difference was detected between Alzheimer and Alzheimerprobiotics group. Conclusion: It seems that probiotics play an effective role in controlling glycemic status of Alzheimer's disease.

Risk assessment, identification, and notification (RAIN) system : a novel approach for traffic management.

DOT National Transportation Integrated Search

2009-08-31

Primary research focused on the design and development of an energy-efficient Risk Notification Message Dissemination Protocol (RNMDP) for vehicular ad hoc networks (VANETs). RNMDP propagates Risk Notification Messages (RNMs) from a location of origi...

Organizing for Reporting.

ERIC Educational Resources Information Center

Wilton, Jennifer

1990-01-01

Reporting occupies a central place in institutional research but is ongoing and never completed. With automation and data management, the proportion of time spent on either routine or ad hoc reporting should decline. This function need not draw unnecessarily from resources for more interesting work. (MSE)

76 FR 19793 - Advisory Committee for Polar Programs; Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-08

... presentations and discussion on opportunities and challenges for polar research, education and infrastructure; discussion of OPP Strategic Vision development; transformative research, ad hoc proposals & program... advise NSF on the impact of its policies, programs, and [[Page 19794

Taming Pipelines, Users, and High Performance Computing with Rector

NASA Astrophysics Data System (ADS)

Estes, N. M.; Bowley, K. S.; Paris, K. N.; Silva, V. H.; Robinson, M. S.

2018-04-01

Rector is a high-performance job management system created by the LROC SOC team to enable processing of thousands of observations and ancillary data products as well as ad-hoc user jobs across a 634 CPU core processing cluster.

HEURISTIC OPTIMIZATION AND ALGORITHM TUNING APPLIED TO SORPTIVE BARRIER DESIGN

EPA Science Inventory

While heuristic optimization is applied in environmental applications, ad-hoc algorithm configuration is typical. We use a multi-layer sorptive barrier design problem as a benchmark for an algorithm-tuning procedure, as applied to three heuristics (genetic algorithms, simulated ...

48 CFR 1336.602-2 - Evaluation boards.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Evaluation boards. 1336...-2 Evaluation boards. Permanent and ad hoc architect-engineer evaluation boards may include... evaluation boards should be comprised of at least a majority of government personnel. ...

76 FR 80890 - Pacific Fishery Management Council; Public Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-27

... Fishery Management Council; Public Meeting AGENCY: National Marine Fisheries Service (NMFS), National... Pacific Fishery Management Council's (Pacific Council) Ad Hoc Groundfish Essential Fish Habitat Review... Airport Hotel, 7900 NE 82nd Avenue, Portland, OR 97220. Council address: Pacific Fishery Management...

Ultra-wideband radar sensors and networks

DOEpatents

Leach, Jr., Richard R; Nekoogar, Faranak; Haugen, Peter C

2013-08-06

Ultra wideband radar motion sensors strategically placed in an area of interest communicate with a wireless ad hoc network to provide remote area surveillance. Swept range impulse radar and a heart and respiration monitor combined with the motion sensor further improves discrimination.

78 FR 9888 - Pacific Fishery Management Council; Public Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-12

... Pacific Fishery Management Council's (Council) Ad Hoc Amendment 24 Workgroup will hold an online webinar... Fishery Management Council; Public Meeting AGENCY: National Marine Fisheries Service (NMFS), National...- 508 when prompted. Council address: Pacific Fishery Management Council, 7700 NE Ambassador Place...

[The Spanish translation of the Manual of Diagnostic Tests and Vaccines for Terrestrial Animals: current and future solutions].

PubMed

Díez, F Gutiérrez; León, F Crespo

2004-12-01

This article presents some of the problems that arose when preparing the Spanish translation of the Manual of Diagnostic Tests and Vaccines for Terrestrial Animals of the World Organisation for Animal Health (OIE). It contains a list of the language and translation problems encountered and the solutions that were found, some of which are only provisional. The problems are in part due to the lack of a multi-lingual terminological database approved by the OIE. The need for such a database, as well as for the harmonisation of veterinary terminology by the OIE Steering Committee and the Ad hoc Group on language policy, is discussed.

The Ad Hoc Mars Airplane science working group. [remotely piloted airplane as a Mars exploration vehicle

NASA Technical Reports Server (NTRS)

Clarke, V. C., Jr.

1978-01-01

The capability of a remotely piloted airplane as a Mars exploration vehicle in the aerial survey mode is assessed. Specific experiment areas covered include: visual imaging; gamma ray and infrared reflectance spectroscopy; gravity field; magnetic field and electromagnetic sounding; and atmospheric composition and dynamics. It is concluded that (1) the most important use of a plane in the aerial survey mode would be in topical studies and returned sample site characterization; (2) the airplane offers the unique capability to do high resolution, oblique imaging, and repeated profile measurements in the atmospheric boundary layer; and (3) it offers the best platform from which to do electromagnetic sounding.

Case Study of 'Engineering Peer Meetings' in JPL's ST-6 Project

NASA Technical Reports Server (NTRS)

Chao, Lawrence P.; Tumer, Irem

2004-01-01

This design process error-proofing case study describes a design review practice implemented by a project manager at NASA Jet Propulsion Laboratory. There are many types of reviews at NASA: required and not, formalized and informal, programmatic and technical. Standing project formal reviews such as the Preliminary Design Review (PDR) and Critical Design Review (CDR) are a required part of every project and mission development. However, the engineering peer reviews that support teams technical work on such projects are often informal, ad hoc, and inconsistent across the organization. This case study discusses issues and innovations identified by a project manager at JPL and implemented in 'engineering peer meetings' for his group.

Case Study of "Engineering Peer Meetings" in JPL's ST-6 Project

NASA Technical Reports Server (NTRS)

Tumer, Irem Y.; Chao, Lawrence P.

2003-01-01

This design process error-proofing case study describes a design review practice implemented by a project manager at NASA Jet Propulsion Laboratory. There are many types of reviews at NASA: required and not, formalized and informal, programmatic and technical. Standing project formal reviews such as the Preliminary Design Review (PDR) and Critical Design Review (CDR) are a required part of every project and mission development. However, the engineering peer reviews that support teams technical work on such projects are often informal, ad hoc, and inconsistent across the organization. This case study discusses issues and innovations identified by a project manager at JPL and implemented in "engineering peer meetings" for his group.

Socio-demographic, behavioral and functional characteristics of groups of community and institutionalized elderly Quechua Indians of Peru, and their association with nutritional status.

PubMed

Fortunato, Laura; Drusini, Andrea G

2005-06-01

Socio-demographic, behavioral, functional and anthropometric data for groups of elderly Quechua Indians of Peru were used to investigate the effects of gender and lifestyle patterns on nutritional status. Two community-dwelling samples were selected for study, representative of divergent lifestyles in terms of their combination of socio-economic, demographic and cultural contexts, plus an ad-hoc sample of institutionalized individuals with controlled food intake and reduced physical activity. Results suggest that differences in socio-demographic, behavioral and functional characteristics exist between the sexes and across settings (low- vs. highland) and lifestyles (institutionalized vs. community-dwelling; semi-urban vs. rural). These factors are likely to be related to diverging dietary and physical activity patterns, and have considerable effects on the nutritional status of the respondents.

The Challenges of Internetworking Unattended Autonomous Sensors

DTIC Science & Technology

2006-12-01

number of nodes that can hear the broadcast by a squared factor. The establishment of path keys for multi-hop range extension should however be used...Conf. on Info. Sci. and Syst. (CISS 󈧅), Baltimore, 21-23 March 2001 [9] R . Ramanathan, “On the Performance of Ad Hoc Networks with Beamforming...Computing”, Prentice Hall PTR, 2002 [12] S. Slijepcevic, M. Potkonjak, V. Tsiatsis, S. Zimbeck, M.B. Srivastava “On Communication Security inWireless Ad

[Implementation of interdisciplinary multimodal pain therapy according to OPS 8‑918 : Recommendations of the ad hoc commission for interdisciplinary multimodal pain therapy of the German Pain Association].

PubMed

Arnold, B; Böger, A; Brinkschmidt, T; Casser, H-R; Irnich, D; Kaiser, U; Klimczyk, K; Lutz, J; Pfingsten, M; Sabatowski, R; Schiltenwolf, M; Söllner, W

2018-02-01

With the implementation of the German diagnosis-related groups (DRG) reimbursement system in hospitals, interdisciplinary multimodal pain therapy was incorporated into the associated catalogue of procedures (OPS 8‑918). Yet, the presented criteria describing the procedure of interdisciplinary multimodal pain therapy are neither precise nor unambiguous. This has led to discrepancies in the interpretation regarding the handling of the procedure-making it difficult for medical services of health insurance companies to evaluate the accordance between the delivered therapy and the required criteria. Since the number of pain units has increased in recent years, the number of examinations by the medical service of health insurance companies has increased. This article, published by the ad hoc commission for interdisciplinary multimodal pain therapy of the German Pain Association, provides specific recommendations for correct implementation of interdisciplinary multimodal pain therapy in routine care. The aim is to achieve a maximum level of accordance between health care providers and the requirements of the medical examiners from health insurance companies. More extensive criteria regarding interdisciplinary multimodal pain treatment in an in-patient setting, especially for patients with chronic and complex pain, are obviously needed. Thus, the authors further discuss specific aspects towards further development of the OPS-code. However, the application of the OPS-code still leaves room regarding treatment intensity and process quality. Therefore, the delivery of pain management in sufficient quantity and quality still remains the responsibility of each health care provider.

77 FR 31329 - Pacific Fishery Management Council; Public Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-25

... Fishery Management Council; Public Meeting AGENCY: National Marine Fisheries Service (NMFS), National... Pacific Fishery Management Council's (Pacific Council) ad hoc South of Humbug Pacific Halibut Workgroup (SHPHW) will hold a conference call to review background material on Pacific Halibut stock assessment...

78 FR 79471 - Discretionary Advisory Committee on Heritable Disorders in Newborns and Children; Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-30

..., 2014, 10:00 a.m. to 3:30 p.m. Place: Virtual via Webinar. Status: The meeting is open to the public...) updates from the Committee's subcommittees and ad-hoc workgroups including Laboratory Standards and...

The Integration of Small Satellites in Maritime Interdiction Operations (MIO)

DTIC Science & Technology

2012-09-01

Interdiction Operation, Networks, Ad-Hoc Networks, AISSat-1, Adaptation, Weak Links, Satellite Tool Kit ( STK ), Tactical Network Topology (TNT). 15. NUMBER...43 B. STK .................................................................................................... 47 1. STK Modeling of... STK ............................. 69 1. Create the Six Satellites ........................................................ 69 2. Create the Facility

What's the Use of Theory?

ERIC Educational Resources Information Center

Thomas, Gary

1997-01-01

Argues against the use of theory in educational inquiry, contending that the meaning of theory is unclear; both personal theory and grand theory inhibit creativity and methodology; and less structured problem solving and ad hoc approaches are more likely to result in pluralistic ideas. (SK)

48 CFR 1436.602-2 - Evaluation boards.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Evaluation boards. 1436...-2 Evaluation boards. HCAs shall establish procedures for providing permanent or ad hoc architect-engineer evaluation boards. Bureau procedures shall provide for the appointment of private practitioners of...

78 FR 68480 - National Science Board

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-14

... NATIONAL SCIENCE FOUNDATION National Science Board The National Science Board's ad hoc Committee on Honorary Awards, pursuant to NSF regulations (45 CFR part 614), the National Science Foundation... gives notice in regard to the scheduling of a meeting for the transaction of National Science Board...

Why caution is recommended with post-hoc individual patient matching for estimation of treatment effect in parallel-group randomized controlled trials: the case of acute stroke trials.

PubMed

Jafari, Nahid; Hearne, John; Churilov, Leonid

2013-11-10

A post-hoc individual patient matching procedure was recently proposed within the context of parallel group randomized clinical trials (RCTs) as a method for estimating treatment effect. In this paper, we consider a post-hoc individual patient matching problem within a parallel group RCT as a multi-objective decision-making problem focussing on the trade-off between the quality of individual matches and the overall percentage of matching. Using acute stroke trials as a context, we utilize exact optimization and simulation techniques to investigate a complex relationship between the overall percentage of individual post-hoc matching, the size of the respective RCT, and the quality of matching on variables highly prognostic for a good functional outcome after stroke, as well as the dispersion in these variables. It is empirically confirmed that a high percentage of individual post-hoc matching can only be achieved when the differences in prognostic baseline variables between individually matched subjects within the same pair are sufficiently large and that the unmatched subjects are qualitatively different to the matched ones. It is concluded that the post-hoc individual matching as a technique for treatment effect estimation in parallel-group RCTs should be exercised with caution because of its propensity to introduce significant bias and reduce validity. If used with appropriate caution and thorough evaluation, this approach can complement other viable alternative approaches for estimating the treatment effect. Copyright © 2013 John Wiley & Sons, Ltd.

Hippocampal volumes among older Indian adults: Comparison with Alzheimer's disease and mild cognitive impairment

PubMed Central

Dhikav, Vikas; Duraisamy, Sharmila; Anand, Kuljeet Singh; Garga, Umesh Chandra

2016-01-01

Background: Hippocampal volume data from India have recently been reported in younger adults. Data in older adults are unknown. The present paper describes hippocampal volume from India among older adults and compares the same with patients having Alzheimer's disease (AD) and mild cognitive impairment (MCI). Materials and Methods: A total of 32 cognitively normal subjects, 20 patients with AD, and 13 patients with MCI were enrolled. Patients were evaluated for the diagnosis of AD/MCI using the National Institute of Neurological and Communicative Disorders and Stroke and the Related Disorders Association criteria and the Clinical Dementia Rating (CDR) Scale (score = 0.5), respectively. Hippocampal volume was measured using magnetic resonance imaging (MRI) machine by manual segmentation (Megnatom Symphony 1.5T scanner) three-dimensional (3D) sequences. Results: Age and duration of illness in the MCI group were 70.6 ± 8.6 years and 1.9 ± 0.9 years, respectively. In the AD group, age and duration of illness were 72 ± 8.1 years and 3.1 ± 2.2 years, respectively. In cognitively normal subjects, the age range was 45-88 years (66.9 ± 10.32) years. Mean mini–mental status examination (MMSE) score of healthy subjects was 28.28 ± 1.33. In the MCI group, MMSE was 27.05 ± 1.79. In the AD group, MMSE was 13.32 ± 5.6. In the healthy group, the hippocampal volume was 2.73 ± 0.53 cm3 on the left side and 2.77 ± 0.6 cm3 on the right side. Likewise, in MCI, the volume on the left side was 2.35 ± 0.42 cm3 and the volume on the right side was 2.36 ± 0.38 cm3. Similarly, in the AD group, the volume on the right side was 1.64 ± 0.55 cm3 and on the left side it was 1.59 ± 0.55 cm3. Post hoc analysis using Tukey's honestly significant difference (HSD) showed, using analysis of variance (ANOVA) that there was a statistically significant difference between healthy and AD (P ≤ 0.01), and between healthy and MCI (P ≤ 0.01) subjects. There was a correlation between MMSE score and hippocampal volume in the AD group. Conclusion: The volume of the hippocampus in older Indian adults was 2.77 ± 0. 6 cm3 on the right side and 2.73 ± 0.52 cm3 on the left side. There was a significant hippocampal volume loss in MCI/AD compared to cognitively normal subjects. PMID:27293329

Role of the α1 blocker doxazosin in alcoholism: a proof-of-concept randomized controlled trial.

PubMed

Kenna, George A; Haass-Koffler, Carolina L; Zywiak, William H; Edwards, Steven M; Brickley, Michael B; Swift, Robert M; Leggio, Lorenzo

2016-07-01

Evidence suggests that the norepinephrine system represents an important treatment target for alcohol dependence (AD) and the α1 -blocker prazosin may reduce alcohol drinking in rodents and alcoholic patients. The α1 -blocker doxazosin demonstrates a more favorable pharmacokinetic profile than prazosin, but has never been studied for AD. A double-blind placebo-controlled randomized clinical trial was conducted in AD individuals seeking outpatient treatment. Doxazosin or matched placebo was titrated to 16 mg/day (or maximum tolerable dose). Drinks per week (DPW) and heavy drinking days (HDD) per week were the primary outcomes. Family history density of alcoholism (FHDA), severity of AD and gender were a priori moderators. Forty-one AD individuals were randomized, 30 (doxazosin = 15) completed the treatment phase and 28 (doxazosin = 14) also completed the follow-up. There were no significant differences between groups on DPW and HDD per week. With FHDA as a moderator, there were significant FHDA × medication interactions for both DPW (pcorrected  = 0.001, d = 1.18) and HDD (pcorrected  = 0.00009, d = 1.30). Post hoc analyses revealed that doxazosin significantly reduced alcohol drinking in AD patients with high FHDA and by contrast increased drinking in those with low FHDA. Doxazosin may be effective selectively in AD patients with high FHDA. This study provides preliminary evidence for personalized medicine using α1 -blockade to treat AD. However, confirmatory studies are required. © 2015 Society for the Study of Addiction.

Identifying strategy for ad hoc percutaneous coronary intervention in patients with anticipated unfavorable radial access: the Little Women study.

PubMed

Sgueglia, Gregory A; Todaro, Daniel; De Santis, Antonella; Conte, Micaela; Gioffrè, Gaetano; Di Giorgio, Angela; D'Errico, Fabrizio; Piccioni, Fabiana; Summaria, Francesco; Gaspardone, Achille

2017-10-16

Transradial percutaneous coronary intervention (PCI) offers important advantages over transfemoral PCI, including better outcomes. However, when there is indication to ad hoc PCI, a 6 French workflow is a common default strategy, hence potentially influencing vascular access selection in patients with anticipated small size radial artery. A multidimensional evaluation was performed to compare two ad hoc interventional strategies in women <160cm: a full 6 French workflow (namely 6 French introducer sheath, diagnostic catheters and guiding catheter) with a modified workflow consisting in the use of 5 French diagnostic catheters preceded by the placement of a 6 French sheath introducer and followed by a 6 French guiding catheter use for PCI. Overall 120 women (68±11years) were enrolled in the study. Coronary angiography has been performed using 5 French or 6 French diagnostic catheters in 57 (47.5%) and 63 (52.5%) cases, respectively. Radial spasm and switch to another access occurred more frequently among women who underwent coronary angiography with 6 French rather than 5 French diagnostic catheters (43% vs. 25%, p=0.03 and 2% vs. 11%, p=0.04, respectively). Total time to guidewire lesion crossing was also significantly higher when PCI has been preceded by 6 French rather than 5 French coronary angiography (23±11min vs 16±7min, p=0.013). In patients with anticipated unfavorable radial access, a workflow consisting in 6 French introducer sheath placement, 5 French coronary angiography, and 6 French coronary intervention is on multiple parameters the most straightforward and effective strategy. Copyright © 2017 Elsevier Inc. All rights reserved.

Statistically Self-Consistent and Accurate Errors for SuperDARN Data

NASA Astrophysics Data System (ADS)

Reimer, A. S.; Hussey, G. C.; McWilliams, K. A.

2018-01-01

The Super Dual Auroral Radar Network (SuperDARN)-fitted data products (e.g., spectral width and velocity) are produced using weighted least squares fitting. We present a new First-Principles Fitting Methodology (FPFM) that utilizes the first-principles approach of Reimer et al. (2016) to estimate the variance of the real and imaginary components of the mean autocorrelation functions (ACFs) lags. SuperDARN ACFs fitted by the FPFM do not use ad hoc or empirical criteria. Currently, the weighting used to fit the ACF lags is derived from ad hoc estimates of the ACF lag variance. Additionally, an overcautious lag filtering criterion is used that sometimes discards data that contains useful information. In low signal-to-noise (SNR) and/or low signal-to-clutter regimes the ad hoc variance and empirical criterion lead to underestimated errors for the fitted parameter because the relative contributions of signal, noise, and clutter to the ACF variance is not taken into consideration. The FPFM variance expressions include contributions of signal, noise, and clutter. The clutter is estimated using the maximal power-based self-clutter estimator derived by Reimer and Hussey (2015). The FPFM was successfully implemented and tested using synthetic ACFs generated with the radar data simulator of Ribeiro, Ponomarenko, et al. (2013). The fitted parameters and the fitted-parameter errors produced by the FPFM are compared with the current SuperDARN fitting software, FITACF. Using self-consistent statistical analysis, the FPFM produces reliable or trustworthy quantitative measures of the errors of the fitted parameters. For an SNR in excess of 3 dB and velocity error below 100 m/s, the FPFM produces 52% more data points than FITACF.

A novel unbalanced multiple description coder for robust video transmission over ad hoc wireless networks

NASA Astrophysics Data System (ADS)

Huang, Feng; Sun, Lifeng; Zhong, Yuzhuo

2006-01-01

Robust transmission of live video over ad hoc wireless networks presents new challenges: high bandwidth requirements are coupled with delay constraints; even a single packet loss causes error propagation until a complete video frame is coded in the intra-mode; ad hoc wireless networks suffer from bursty packet losses that drastically degrade the viewing experience. Accordingly, we propose a novel UMD coder capable of quickly recovering from losses and ensuring continuous playout. It uses 'peg' frames to prevent error propagation in the High-Resolution (HR) description and improve the robustness of key frames. The Low-Resolution (LR) coder works independent of the HR one, but they can also help each other recover from losses. Like many UMD coders, our UMD coder is drift-free, disruption-tolerant and able to make good use of the asymmetric available bandwidths of multiple paths. The simulation results under different conditions show that the proposed UMD coder has the highest decoded quality and lowest probability of pause when compared with concurrent UMDC techniques. The coder also has a comparable decoded quality, lower startup delay and lower probability of pause than a state-of-the-art FEC-based scheme. To provide robustness for video multicast applications, we propose non-end-to-end UMDC-based video distribution over a multi-tree multicast network. The multiplicity of parents decorrelates losses and the non-end-to-end feature increases the throughput of UMDC video data. We deploy an application-level service of LR description reconstruction in some intermediate nodes of the LR multicast tree. The principle behind this is to reconstruct the disrupted LR frames by the correctly received HR frames. As a result, the viewing experience at the downstream nodes benefits from the protection reconstruction at the upstream nodes.

A Family of ACO Routing Protocols for Mobile Ad Hoc Networks

PubMed Central

Rupérez Cañas, Delfín; Sandoval Orozco, Ana Lucila; García Villalba, Luis Javier; Kim, Tai-hoon

2017-01-01

In this work, an ACO routing protocol for mobile ad hoc networks based on AntHocNet is specified. As its predecessor, this new protocol, called AntOR, is hybrid in the sense that it contains elements from both reactive and proactive routing. Specifically, it combines a reactive route setup process with a proactive route maintenance and improvement process. Key aspects of the AntOR protocol are the disjoint-link and disjoint-node routes, separation between the regular pheromone and the virtual pheromone in the diffusion process and the exploration of routes, taking into consideration the number of hops in the best routes. In this work, a family of ACO routing protocols based on AntOR is also specified. These protocols are based on protocol successive refinements. In this work, we also present a parallelized version of AntOR that we call PAntOR. Using programming multiprocessor architectures based on the shared memory protocol, PAntOR allows running tasks in parallel using threads. This parallelization is applicable in the route setup phase, route local repair process and link failure notification. In addition, a variant of PAntOR that consists of having more than one interface, which we call PAntOR-MI (PAntOR-Multiple Interface), is specified. This approach parallelizes the sending of broadcast messages by interface through threads. PMID:28531159

76 FR 51378 - National Cancer Institute; Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-18

... DEPARTMENT OF HEALTH AND HUMAN SERVICES National Institutes of Health National Cancer Institute.... App.), notice is hereby given of a meeting of the National Cancer Institute Board of Scientific... Committee: National Cancer Institute Board of Scientific Advisors, caBIG Oversight Ad hoc Subcommittee. Date...

Vehicle infrastructure integration (VII) : exploring the application of disruptive technology to assist older drivers.

DOT National Transportation Integrated Search

2012-01-01

This report discusses the approach and findings of a research project aimed at the evaluation of : an inter-vehicle communications scheme for Vehicular Ad hoc Networks (VANETs). : Because of the size, frequency, and expected number of receivers of pe...

The Need for Systematic Identification of Stakeholders for Public Engagement with Environmental Research

EPA Science Inventory

Despite the increasing promotion of stakeholder engagement in science contributing to environmental decision making, the mechanisms for identifying which stakeholders should be included are rarely strategic or documented. When documented, many of these efforts use ad hoc and/or ...

A Guide for Hard Times in Academia

ERIC Educational Resources Information Center

Reeves, Thomas C.

2003-01-01

The author lampoons twenty-first-century academic priorities. Using a fictional campus facing state-mandated budget reductions, the author parodies a system that retains high-salaried administrative and public relations positions, special-interest majors, athletic programs and junior/ad-hoc faculty, while relinquishing admissions staff, library…

77 FR 9211 - South Atlantic Fishery Management Council; Public Meetings

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-16

... Panel; Ad Hoc Data Collection Committee; Law Enforcement Committee; Spiny Lobster Committee; Ecosystem... Amendment 20B (wreckfish Individual Transferable Quota (ITQ) program modifications); Spiny Lobster Amendment... report from the Law Enforcement AP and discuss other issues as appropriate. 4. Spiny Lobster Committee...

77 FR 45591 - Pacific Fishery Management Council; Public Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-01

... Fishery Management Council; Public Meeting AGENCY: National Marine Fisheries Service (NMFS), National... Pacific Fishery Management Council's (Pacific Council) Ad Hoc South of Humbug Pacific Halibut Workgroup..., monitoring, and allocation history of Pacific halibut in the area south of Humbug Mt. DATES: The conference...

Scalable Mobile Ad Hoc Network (MANET) to Enhance Situational Awareness in Distributed Small Unit Operations

DTIC Science & Technology

2015-06-01

raspberry pi , robotic operation system (ros), arduino 15. NUMBER OF PAGES 123 16. PRICE CODE 17. SECURITY CLASSIFICATION OF REPORT...51  2.  Raspberry Pi ...52  Figure 21.  The Raspberry Pi B+ model, from [24

Relationships in Data Sanitization: A Study in Scarlet

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

Bishop, Matt; Cummins, Justin; Peisert, Sean

2010-09-23

Data anonymization and sanitization are essential components to using and sharing data, but most approaches to performing those actions either fail to take into account all of the stakeholders, are ad hoc, or both. In this paper, we discuss a means of doing so.

Trust Management and Accountability for Internet Security

ERIC Educational Resources Information Center

Liu, Wayne W.

2011-01-01

Adversarial yet interacting interdependent relationships in information sharing and service provisioning have been a pressing issue of the Internet. Such relationships exist among autonomous software agents, in networking system peers, as well as between "service users and providers." Traditional "ad hoc" security approaches effective in…

76 FR 77840 - Statement of Organization, Functions and Delegations of Authority

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-14

... current liaison functions and grant policy processes within the Office of Federal Assistance Management... processes related to assistance programs; (3) facilitates, plans, directs and coordinates the administration... review of grant applicants' and grantees' accounting systems; (5) conducts ad hoc studies and reviews...

Verifying Safety Messages Using Relative-Time and Zone Priority in Vehicular Ad Hoc Networks.

PubMed

Banani, Sam; Gordon, Steven; Thiemjarus, Surapa; Kittipiyakul, Somsak

2018-04-13

In high-density road networks, with each vehicle broadcasting multiple messages per second, the arrival rate of safety messages can easily exceed the rate at which digital signatures can be verified. Since not all messages can be verified, algorithms for selecting which messages to verify are required to ensure that each vehicle receives appropriate awareness about neighbouring vehicles. This paper presents a novel scheme to select important safety messages for verification in vehicular ad hoc networks (VANETs). The proposed scheme uses location and direction of the sender, as well as proximity and relative-time between vehicles, to reduce the number of irrelevant messages verified (i.e., messages from vehicles that are unlikely to cause an accident). Compared with other existing schemes, the analysis results show that the proposed scheme can verify messages from nearby vehicles with lower inter-message delay and reduced packet loss and thus provides high level of awareness of the nearby vehicles.

Spontaneous Ad Hoc Mobile Cloud Computing Network

PubMed Central

Lacuesta, Raquel; Sendra, Sandra; Peñalver, Lourdes

2014-01-01

Cloud computing helps users and companies to share computing resources instead of having local servers or personal devices to handle the applications. Smart devices are becoming one of the main information processing devices. Their computing features are reaching levels that let them create a mobile cloud computing network. But sometimes they are not able to create it and collaborate actively in the cloud because it is difficult for them to build easily a spontaneous network and configure its parameters. For this reason, in this paper, we are going to present the design and deployment of a spontaneous ad hoc mobile cloud computing network. In order to perform it, we have developed a trusted algorithm that is able to manage the activity of the nodes when they join and leave the network. The paper shows the network procedures and classes that have been designed. Our simulation results using Castalia show that our proposal presents a good efficiency and network performance even by using high number of nodes. PMID:25202715

An Energy-Efficient and Robust Multipath Routing Protocol for Cognitive Radio Ad Hoc Networks.

PubMed

Singh, Kishor; Moh, Sangman

2017-09-04

Routing in cognitive radio ad hoc networks (CRAHNs) is a daunting task owing to dynamic topology, intermittent connectivity, spectrum heterogeneity, and energy constraints. Other prominent aspects such as channel stability, path reliability, and route discovery frequency should also be exploited. Several routing protocols have been proposed for CRAHNs in the literature. By stressing on one of the aspects more than any other, however, they do not satisfy all requirements of throughput, energy efficiency, and robustness. In this paper, we propose an energy-efficient and robust multipath routing (ERMR) protocol for CRAHNs by considering all prominent aspects including residual energy and channel stability in design. Even when the current routing path fails, the alternative routing path is immediately utilized. In establishing primary and alternative routing paths, both residual energy and channel stability are exploited simultaneously. Our simulation study shows that the proposed ERMR outperforms the conventional protocol in terms of network throughput, packet delivery ratio, energy consumption, and end-to-end delay.

Spontaneous ad hoc mobile cloud computing network.

PubMed

Lacuesta, Raquel; Lloret, Jaime; Sendra, Sandra; Peñalver, Lourdes

2014-01-01

Cloud computing helps users and companies to share computing resources instead of having local servers or personal devices to handle the applications. Smart devices are becoming one of the main information processing devices. Their computing features are reaching levels that let them create a mobile cloud computing network. But sometimes they are not able to create it and collaborate actively in the cloud because it is difficult for them to build easily a spontaneous network and configure its parameters. For this reason, in this paper, we are going to present the design and deployment of a spontaneous ad hoc mobile cloud computing network. In order to perform it, we have developed a trusted algorithm that is able to manage the activity of the nodes when they join and leave the network. The paper shows the network procedures and classes that have been designed. Our simulation results using Castalia show that our proposal presents a good efficiency and network performance even by using high number of nodes.

Science friction: data, metadata, and collaboration.

PubMed

Edwards, Paul N; Mayernik, Matthew S; Batcheller, Archer L; Bowker, Geoffrey C; Borgman, Christine L

2011-10-01

When scientists from two or more disciplines work together on related problems, they often face what we call 'science friction'. As science becomes more data-driven, collaborative, and interdisciplinary, demand increases for interoperability among data, tools, and services. Metadata--usually viewed simply as 'data about data', describing objects such as books, journal articles, or datasets--serve key roles in interoperability. Yet we find that metadata may be a source of friction between scientific collaborators, impeding data sharing. We propose an alternative view of metadata, focusing on its role in an ephemeral process of scientific communication, rather than as an enduring outcome or product. We report examples of highly useful, yet ad hoc, incomplete, loosely structured, and mutable, descriptions of data found in our ethnographic studies of several large projects in the environmental sciences. Based on this evidence, we argue that while metadata products can be powerful resources, usually they must be supplemented with metadata processes. Metadata-as-process suggests the very large role of the ad hoc, the incomplete, and the unfinished in everyday scientific work.

A multimetric, map-aware routing protocol for VANETs in urban areas.

PubMed

Tripp-Barba, Carolina; Urquiza-Aguiar, Luis; Aguilar Igartua, Mónica; Rebollo-Monedero, David; de la Cruz Llopis, Luis J; Mezher, Ahmad Mohamad; Aguilar-Calderón, José Alfonso

2014-01-28

In recent years, the general interest in routing for vehicular ad hoc networks (VANETs) has increased notably. Many proposals have been presented to improve the behavior of the routing decisions in these very changeable networks. In this paper, we propose a new routing protocol for VANETs that uses four different metrics. which are the distance to destination, the vehicles' density, the vehicles' trajectory and the available bandwidth, making use of the information retrieved by the sensors of the vehicle, in order to make forwarding decisions, minimizing packet losses and packet delay. Through simulation, we compare our proposal to other protocols, such as AODV (Ad hoc On-Demand Distance Vector), GPSR (Greedy Perimeter Stateless Routing), I-GPSR (Improvement GPSR) and to our previous proposal, GBSR-B (Greedy Buffer Stateless Routing Building-aware). Besides, we present a performance evaluation of the individual importance of each metric to make forwarding decisions. Experimental results show that our proposed forwarding decision outperforms existing solutions in terms of packet delivery.

An Energy-Efficient and Robust Multipath Routing Protocol for Cognitive Radio Ad Hoc Networks

PubMed Central

Singh, Kishor

2017-01-01

Routing in cognitive radio ad hoc networks (CRAHNs) is a daunting task owing to dynamic topology, intermittent connectivity, spectrum heterogeneity, and energy constraints. Other prominent aspects such as channel stability, path reliability, and route discovery frequency should also be exploited. Several routing protocols have been proposed for CRAHNs in the literature. By stressing on one of the aspects more than any other, however, they do not satisfy all requirements of throughput, energy efficiency, and robustness. In this paper, we propose an energy-efficient and robust multipath routing (ERMR) protocol for CRAHNs by considering all prominent aspects including residual energy and channel stability in design. Even when the current routing path fails, the alternative routing path is immediately utilized. In establishing primary and alternative routing paths, both residual energy and channel stability are exploited simultaneously. Our simulation study shows that the proposed ERMR outperforms the conventional protocol in terms of network throughput, packet delivery ratio, energy consumption, and end-to-end delay. PMID:28869551

Hop Optimization and Relay Node Selection in Multi-hop Wireless Ad-Hoc Networks

NASA Astrophysics Data System (ADS)

Li, Xiaohua(Edward)

In this paper we propose an efficient approach to determine the optimal hops for multi-hop ad hoc wireless networks. Based on the assumption that nodes use successive interference cancellation (SIC) and maximal ratio combining (MRC) to deal with mutual interference and to utilize all the received signal energy, we show that the signal-to-interference-plus-noise ratio (SINR) of a node is determined only by the nodes before it, not the nodes after it, along a packet forwarding path. Based on this observation, we propose an iterative procedure to select the relay nodes and to calculate the path SINR as well as capacity of an arbitrary multi-hop packet forwarding path. The complexity of the algorithm is extremely low, and scaling well with network size. The algorithm is applicable in arbitrarily large networks. Its performance is demonstrated as desirable by simulations. The algorithm can be helpful in analyzing the performance of multi-hop wireless networks.

Data management issues in mobile ad hoc networks

PubMed Central

HARA, Takahiro

2017-01-01

Research on mobile ad hoc networks (MANETs) has become a hot research topic since the middle 1990’s. Over the first decade, most research focused on networking techniques, ignoring data management issues. We, however, realized early the importance of data management in MANETs, and have been conducting studies in this area for 15 years. In this review, we summarize some key technical issues related to data management in MANETs, and the studies we have done in addressing these issues, which include placement of data replicas, update management, and query processing with security management. The techniques proposed in our studies have been designed with deep considerations of MANET features including network partitioning, node participation/disappearance, limited network bandwidth, and energy efficiency. Our studies published in early 2000’s have developed a new research field as data management in MANETs. Also, our recent studies are expected to be significant guidelines of new research directions. We conclude the review by discussing some future directions for research. PMID:28496052

An Adaptive QoS Routing Solution for MANET Based Multimedia Communications in Emergency Cases

NASA Astrophysics Data System (ADS)

Ramrekha, Tipu Arvind; Politis, Christos

The Mobile Ad hoc Networks (MANET) is a wireless network deprived of any fixed central authoritative routing entity. It relies entirely on collaborating nodes forwarding packets from source to destination. This paper describes the design, implementation and performance evaluation of CHAMELEON, an adaptive Quality of Service (QoS) routing solution, with improved delay and jitter performances, enabling multimedia communication for MANETs in extreme emergency situations such as forest fire and terrorist attacks as defined in the PEACE project. CHAMELEON is designed to adapt its routing behaviour according to the size of a MANET. The reactive Ad Hoc on-Demand Distance Vector Routing (AODV) and proactive Optimized Link State Routing (OLSR) protocols are deemed appropriate for CHAMELEON through their performance evaluation in terms of delay and jitter for different MANET sizes in a building fire emergency scenario. CHAMELEON is then implemented in NS-2 and evaluated similarly. The paper concludes with a summary of findings so far and intended future work.

Verifying Safety Messages Using Relative-Time and Zone Priority in Vehicular Ad Hoc Networks

PubMed Central

Banani, Sam; Thiemjarus, Surapa; Kittipiyakul, Somsak

2018-01-01

In high-density road networks, with each vehicle broadcasting multiple messages per second, the arrival rate of safety messages can easily exceed the rate at which digital signatures can be verified. Since not all messages can be verified, algorithms for selecting which messages to verify are required to ensure that each vehicle receives appropriate awareness about neighbouring vehicles. This paper presents a novel scheme to select important safety messages for verification in vehicular ad hoc networks (VANETs). The proposed scheme uses location and direction of the sender, as well as proximity and relative-time between vehicles, to reduce the number of irrelevant messages verified (i.e., messages from vehicles that are unlikely to cause an accident). Compared with other existing schemes, the analysis results show that the proposed scheme can verify messages from nearby vehicles with lower inter-message delay and reduced packet loss and thus provides high level of awareness of the nearby vehicles. PMID:29652840

Ad-hoc surface-enhanced Raman spectroscopy methodologies for the detection of artist dyestuffs: thin layer chromatography-surface enhanced Raman spectroscopy and in situ on the fiber analysis.

PubMed

Brosseau, Christa L; Gambardella, Alessa; Casadio, Francesca; Grzywacz, Cecily M; Wouters, Jan; Van Duyne, Richard P

2009-04-15

Tailored ad-hoc methods must be developed for successful identification of minute amounts of natural dyes on works of art using Surface-Enhanced Raman Spectroscopy (SERS). This article details two of these successful approaches using silver film over nanosphere (AgFON) substrates and silica gel coupled with citrate-reduced Ag colloids. The latter substrate functions as the test system for the coupling of thin-layer chromatography and SERS (TLC-SERS), which has been used in the current research to separate and characterize a mixture of several artists' dyes. The poor limit of detection of TLC is overcome by coupling with SERS, and dyes which co-elute to nearly the same spot can be distinguished from each other. In addition, in situ extractionless non-hydrolysis SERS was used to analyze dyed reference fibers, as well as historical textile fibers. Colorants such as alizarin, purpurin, carminic acid, lac dye, crocin, and Cape jasmine were thus successfully identified.

Data management issues in mobile ad hoc networks.

PubMed

Hara, Takahiro

2017-01-01

Research on mobile ad hoc networks (MANETs) has become a hot research topic since the middle 1990's. Over the first decade, most research focused on networking techniques, ignoring data management issues. We, however, realized early the importance of data management in MANETs, and have been conducting studies in this area for 15 years. In this review, we summarize some key technical issues related to data management in MANETs, and the studies we have done in addressing these issues, which include placement of data replicas, update management, and query processing with security management. The techniques proposed in our studies have been designed with deep considerations of MANET features including network partitioning, node participation/disappearance, limited network bandwidth, and energy efficiency. Our studies published in early 2000's have developed a new research field as data management in MANETs. Also, our recent studies are expected to be significant guidelines of new research directions. We conclude the review by discussing some future directions for research.

Quality of service routing in wireless ad hoc networks

NASA Astrophysics Data System (ADS)

Sane, Sachin J.; Patcha, Animesh; Mishra, Amitabh

2003-08-01

An efficient routing protocol is essential to guarantee application level quality of service running on wireless ad hoc networks. In this paper we propose a novel routing algorithm that computes a path between a source and a destination by considering several important constraints such as path-life, availability of sufficient energy as well as buffer space in each of the nodes on the path between the source and destination. The algorithm chooses the best path from among the multiples paths that it computes between two endpoints. We consider the use of control packets that run at a priority higher than the data packets in determining the multiple paths. The paper also examines the impact of different schedulers such as weighted fair queuing, and weighted random early detection among others in preserving the QoS level guarantees. Our extensive simulation results indicate that the algorithm improves the overall lifetime of a network, reduces the number of dropped packets, and decreases the end-to-end delay for real-time voice application.

Ad Hoc modeling, expert problem solving, and R&T program evaluation

NASA Technical Reports Server (NTRS)

Silverman, B. G.; Liebowitz, J.; Moustakis, V. S.

1983-01-01

A simplified cost and time (SCAT) analysis program utilizing personal-computer technology is presented and demonstrated in the case of the NASA-Goddard end-to-end data system. The difficulties encountered in implementing complex program-selection and evaluation models in the research and technology field are outlined. The prototype SCAT system described here is designed to allow user-friendly ad hoc modeling in real time and at low cost. A worksheet constructed on the computer screen displays the critical parameters and shows how each is affected when one is altered experimentally. In the NASA case, satellite data-output and control requirements, ground-facility data-handling capabilities, and project priorities are intricately interrelated. Scenario studies of the effects of spacecraft phaseout or new spacecraft on throughput and delay parameters are shown. The use of a network of personal computers for higher-level coordination of decision-making processes is suggested, as a complement or alternative to complex large-scale modeling.

A closed-form trim solution yielding minimum trim drag for airplanes with multiple longitudinal-control effectors

NASA Technical Reports Server (NTRS)

Goodrich, Kenneth H.; Sliwa, Steven M.; Lallman, Frederick J.

1989-01-01

Airplane designs are currently being proposed with a multitude of lifting and control devices. Because of the redundancy in ways to generate moments and forces, there are a variety of strategies for trimming each airplane. A linear optimum trim solution (LOTS) is derived using a Lagrange formulation. LOTS enables the rapid calculation of the longitudinal load distribution resulting in the minimum trim drag in level, steady-state flight for airplanes with a mixture of three or more aerodynamic surfaces and propulsive control effectors. Comparisons of the trim drags obtained using LOTS, a direct constrained optimization method, and several ad hoc methods are presented for vortex-lattice representations of a three-surface airplane and two-surface airplane with thrust vectoring. These comparisons show that LOTS accurately predicts the results obtained from the nonlinear optimization and that the optimum methods result in trim drag reductions of up to 80 percent compared to the ad hoc methods.

The Vehicular Information Space Framework

NASA Astrophysics Data System (ADS)

Prinz, Vivian; Schlichter, Johann; Schweiger, Benno

Vehicular networks are distributed, self-organizing and highly mobile ad hoc networks. They allow for providing drivers with up-to-the-minute information about their environment. Therefore, they are expected to be a decisive future enabler for enhancing driving comfort and safety. This article introduces the Vehicular Information Space framework (VIS). Vehicles running the VIS form a kind of distributed database. It enables them to provide information like existing hazards, parking spaces or traffic densities in a location aware and fully distributed manner. In addition, vehicles can retrieve, modify and delete these information items. The underlying algorithm is based on features derived from existing structured Peer-to-Peer algorithms and extended to suit the specific characteristics of highly mobile ad hoc networks. We present, implement and simulate the VIS using a motorway and an urban traffic environment. Simulation studies on VIS message occurrence show that the VIS implies reasonable traffic overhead. Also, overall VIS message traffic is independent from the number of information items provided.

Functional Fixedness in Creative Thinking Tasks Depends on Stimulus Modality.

PubMed

Chrysikou, Evangelia G; Motyka, Katharine; Nigro, Cristina; Yang, Song-I; Thompson-Schill, Sharon L

2016-11-01

Pictorial examples during creative thinking tasks can lead participants to fixate on these examples and reproduce their elements even when yielding suboptimal creative products. Semantic memory research may illuminate the cognitive processes underlying this effect. Here, we examined whether pictures and words differentially influence access to semantic knowledge for object concepts depending on whether the task is close- or open-ended. Participants viewed either names or pictures of everyday objects, or a combination of the two, and generated common, secondary, or ad hoc uses for them. Stimulus modality effects were assessed quantitatively through reaction times and qualitatively through a novel coding system, which classifies creative output on a continuum from top-down-driven to bottom-up-driven responses. Both analyses revealed differences across tasks. Importantly, for ad hoc uses, participants exposed to pictures generated more top-down-driven responses than those exposed to object names. These findings have implications for accounts of functional fixedness in creative thinking, as well as theories of semantic memory for object concepts.

Functional Fixedness in Creative Thinking Tasks Depends on Stimulus Modality

PubMed Central

Chrysikou, Evangelia G.; Motyka, Katharine; Nigro, Cristina; Yang, Song-I; Thompson-Schill, Sharon L.

2015-01-01

Pictorial examples during creative thinking tasks can lead participants to fixate on these examples and reproduce their elements even when yielding suboptimal creative products. Semantic memory research may illuminate the cognitive processes underlying this effect. Here, we examined whether pictures and words differentially influence access to semantic knowledge for object concepts depending on whether the task is close- or open-ended. Participants viewed either names or pictures of everyday objects, or a combination of the two, and generated common, secondary, or ad hoc uses for them. Stimulus modality effects were assessed quantitatively through reaction times and qualitatively through a novel coding system, which classifies creative output on a continuum from top-down-driven to bottom-up-driven responses. Both analyses revealed differences across tasks. Importantly, for ad hoc uses, participants exposed to pictures generated more top-down-driven responses than those exposed to object names. These findings have implications for accounts of functional fixedness in creative thinking, as well as theories of semantic memory for object concepts. PMID:28344724

Reduced-order modeling for hyperthermia: an extended balanced-realization-based approach.

PubMed

Mattingly, M; Bailey, E A; Dutton, A W; Roemer, R B; Devasia, S

1998-09-01

Accurate thermal models are needed in hyperthermia cancer treatments for such tasks as actuator and sensor placement design, parameter estimation, and feedback temperature control. The complexity of the human body produces full-order models which are too large for effective execution of these tasks, making use of reduced-order models necessary. However, standard balanced-realization (SBR)-based model reduction techniques require a priori knowledge of the particular placement of actuators and sensors for model reduction. Since placement design is intractable (computationally) on the full-order models, SBR techniques must use ad hoc placements. To alleviate this problem, an extended balanced-realization (EBR)-based model-order reduction approach is presented. The new technique allows model order reduction to be performed over all possible placement designs and does not require ad hoc placement designs. It is shown that models obtained using the EBR method are more robust to intratreatment changes in the placement of the applied power field than those models obtained using the SBR method.

Adaptive Admissions Process for Effective and Fair Graduate Admission

ERIC Educational Resources Information Center

Zimmermann, Judith; von Davier, Alina; Heinimann, Hans Rudolf

2017-01-01

Purpose: Graduate admission has become a critical process for quality assurance in tertiary education. Hitherto, most research has investigated the validity of admissions instruments. However, surprisingly little work has been conducted on the overall organization of admission, which often remains "informal, ad hoc, and lacking in…

77 FR 28543 - Nationwide Health Information Network: Conditions for Trusted Exchange

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-15

... expansion, electronic exchange has been governed by a patchwork of contractual relationships, procurement.... Consequently, this ad-hoc governance approach has led to asymmetries in the policies and technical standards... This request for information (RFI) reflects ONC's current thinking regarding the approach ONC should...

Average Likelihood Methods of Classification of Code Division Multiple Access (CDMA)

DTIC Science & Technology

2016-05-01

case of cognitive radio applications. Modulation classification is part of a broader problem known as blind or uncooperative demodulation the goal of...Introduction 2 2.1 Modulation Classification . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 2.2 Research Objectives...6 3 Modulation Classification Methods 7 3.0.1 Ad Hoc

Three Case Studies on Business Collaboration and Process Management

ERIC Educational Resources Information Center

Fan, Shaokun

2012-01-01

The importance of collaboration has been recognized for more than 2000 years. While recent improvement in technology creates vast opportunities for collaboration, effective collaboration remains challenging as ad hoc teams work across time, geographical, language, and technical boundaries, and suffer from process inefficiency. My dissertation…

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

ERIC Educational Resources Information Center

Fisher, B. Aubrey; And Others

1979-01-01

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

EVALUATION AND ANALYSIS OF MICROSCALE FLOW AND TRANSPORT DURING REMEDIATION

EPA Science Inventory

The design of in-situ remediation is currently based on a description at the macroscopic scale. Phenomena at the pore and pore-network scales are typically lumped in terms of averaged quantities, using empirical or ad hoc expressions. These models cannot address fundamental rem...

What Is a Psychological Misconception? Moving toward an Empirical Answer

ERIC Educational Resources Information Center

Bensley, D. Alan; Lilienfeld, Scott O.

2015-01-01

Studies of psychological misconceptions have often used tests with methodological shortcomings, unknown psychometric properties, and ad hoc methods for identifying misconceptions, creating problems for estimating frequencies of specific misconceptions. To address these problems, we developed a new test, the Test of Psychological Knowledge and…

Location-Based Services in Vehicular Networks

ERIC Educational Resources Information Center

Wu, Di

2013-01-01

Location-based services have been identified as a promising communication paradigm in highly mobile and dynamic vehicular networks. However, existing mobile ad hoc networking cannot be directly applied to vehicular networking due to differences in traffic conditions, mobility models and network topologies. On the other hand, hybrid architectures…

75 FR 26267 - National Cancer Institute; Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-11

... DEPARTMENT OF HEALTH AND HUMAN SERVICES National Institutes of Health National Cancer Institute.... Appendix 2), notice is hereby given of the meeting of the National Cancer Advisory Board. The meeting will... clearly unwarranted invasion of personal privacy. Name of Committee: National Cancer Advisory Board Ad hoc...

Ad Hoc Network Architecture for Multi-Media Networks

DTIC Science & Technology

2007-12-01

sensor network . Video traffic is modeled and simulations are performed via the use of the Sun Small Programmable Object Technology (Sun SPOT) Java...characteristics of video traffic must be studied and understood. This thesis focuses on evaluating the possibility of routing video images over a wireless

Collaboration and decision making tools for mobile groups

NASA Astrophysics Data System (ADS)

Abrahamyan, Suren; Balyan, Serob; Ter-Minasyan, Harutyun; Degtyarev, Alexander

2017-12-01

Nowadays the use of distributed collaboration tools is widespread in many areas of people activity. But lack of mobility and certain equipment-dependency creates difficulties and decelerates development and integration of such technologies. Also mobile technologies allow individuals to interact with each other without need of traditional office spaces and regardless of location. Hence, realization of special infrastructures on mobile platforms with help of ad-hoc wireless local networks could eliminate hardware-attachment and be useful also in terms of scientific approach. Solutions from basic internet-messengers to complex software for online collaboration equipment in large-scale workgroups are implementations of tools based on mobile infrastructures. Despite growth of mobile infrastructures, applied distributed solutions in group decisionmaking and e-collaboration are not common. In this article we propose software complex for real-time collaboration and decision-making based on mobile devices, describe its architecture and evaluate performance.

Health Vlogs as Social Support for Chronic Illness Management.

PubMed

Huh, Jina; Liu, Leslie S; Neogi, Tina; Inkpen, Kori; Pratt, Wanda

2014-08-01

Studies have shown positive impact of video blogs (vlogs) on patient education. However, we know little on how patient-initiated vlogs shape the relationships among vloggers and viewers. We qualitatively analyzed 72 vlogs on YouTube by users diagnosed with HIV, diabetes, or cancer and 1,274 comments posted to the vlogs to understand viewers' perspectives on the vlogs. We found that the unique video medium allowed intense and enriched personal and contextual disclosure to the viewers, leading to strong community-building activities and social support among vloggers and commenters, both informationally and emotionally. Furthermore, the unique communication structure of the vlogs allowed ad hoc small groups to form, which showed different group behavior than typical text-based social media, such as online communities. We provide implications to the Health Care Industry (HCI) community on how future technologies for health vlogs could be designed to further support chronic illness management.

What proportion of congenital abnormalities can be prevented?

PubMed Central

Czeizel, A E; Intôdy, Z; Modell, B

1993-01-01

OBJECTIVE--To estimate the proportion of preventable congenital abnormalities in Hungary. DESIGN--Analysis of available Hungarian data-bases and of the effectiveness of primary, secondary, and tertiary preventive methods. SETTING--Databases of ad hoc epidemiological studies and of the Hungarian congenital abnormality registry. MAIN OUTCOME MEASURES--Prevalence at birth and prevalence after prevention in 73 congenital abnormality types or groups. RESULTS--Preventive methods are available for 51 (70%) of the 73 congenital abnormality types or groups evaluated. The birth prevalence of all congenital abnormalities could be reduced from 65 to 26 per 1000; thus 39 per 1000 (60%) are preventable. Without congenital dislocation of the hip, which is unusually common in Hungary, the preventable proportion of congenital abnormalities is 52%. CONCLUSION--Many congenital abnormalities can be prevented, but as they do not represent a single pathological category there is no single strategy for their prevention. Images p502-a p503-a PMID:8448464

Effects of a Problem-based Structure of Physics Contents on Conceptual Learning and the Ability to Solve Problems

NASA Astrophysics Data System (ADS)

Becerra-Labra, Carlos; Gras-Martí, Albert; Martínez Torregrosa, Joaquín

2012-05-01

A model of teaching/learning is proposed based on a 'problem-based structure' of the contents of the course, in combination with a training in paper and pencil problem solving that emphasizes discussion and quantitative analysis, rather than formulae plug-in. The aim is to reverse the high failure and attrition rate among engineering undergraduates taking physics. A number of tests and questionnaires were administered to a group of students following a traditional lecture-based instruction, as well as to another group that was following an instruction scheme based on the proposed approach and the teaching materials developed ad hoc. The results show that students following the new method can develop scientific reasoning habits in problem-solving skills, and show gains in conceptual learning, attitudes and interests, and that the effects of this approach on learning are noticeable several months after the course is over.

Health Vlogs as Social Support for Chronic Illness Management

PubMed Central

HUH, JINA; LIU, LESLIE S.; NEOGI, TINA; INKPEN, KORI; PRATT, WANDA

2015-01-01

Studies have shown positive impact of video blogs (vlogs) on patient education. However, we know little on how patient-initiated vlogs shape the relationships among vloggers and viewers. We qualitatively analyzed 72 vlogs on YouTube by users diagnosed with HIV, diabetes, or cancer and 1,274 comments posted to the vlogs to understand viewers’ perspectives on the vlogs. We found that the unique video medium allowed intense and enriched personal and contextual disclosure to the viewers, leading to strong community-building activities and social support among vloggers and commenters, both informationally and emotionally. Furthermore, the unique communication structure of the vlogs allowed ad hoc small groups to form, which showed different group behavior than typical text-based social media, such as online communities. We provide implications to the Health Care Industry (HCI) community on how future technologies for health vlogs could be designed to further support chronic illness management. PMID:26146474

Primary Immunodeficiency Diseases: An Update on the Classification from the International Union of Immunological Societies Expert Committee for Primary Immunodeficiency

PubMed Central

Al-Herz, Waleed; Bousfiha, Aziz; Casanova, Jean-Laurent; Chapel, Helen; Conley, Mary Ellen; Cunningham-Rundles, Charlotte; Etzioni, Amos; Fischer, Alain; Franco, Jose Luis; Geha, Raif S.; Hammarström, Lennart; Nonoyama, Shigeaki; Notarangelo, Luigi Daniele; Ochs, Hans Dieter; Puck, Jennifer M.; Roifman, Chaim M.; Seger, Reinhard; Tang, Mimi L. K.

2011-01-01

We report the updated classification of primary immunodeficiency diseases, compiled by the ad hoc Expert Committee of the International Union of Immunological Societies. As compared to the previous edition, more than 15 novel disease entities have been added in the updated version. For each disorders, the key clinical and laboratory features are provided. This updated classification is meant to help in the diagnostic approach to patients with these diseases. PMID:22566844

Incorporating ISO Metadata Using HDF Product Designer

NASA Technical Reports Server (NTRS)

Jelenak, Aleksandar; Kozimor, John; Habermann, Ted

2016-01-01

The need to store in HDF5 files increasing amounts of metadata of various complexity is greatly overcoming the capabilities of the Earth science metadata conventions currently in use. Data producers until now did not have much choice but to come up with ad hoc solutions to this challenge. Such solutions, in turn, pose a wide range of issues for data managers, distributors, and, ultimately, data users. The HDF Group is experimenting on a novel approach of using ISO 19115 metadata objects as a catch-all container for all the metadata that cannot be fitted into the current Earth science data conventions. This presentation will showcase how the HDF Product Designer software can be utilized to help data producers include various ISO metadata objects in their products.

The position of the New York Academy of Medicine on physician-assisted suicide.

PubMed

Barondess, J A

1997-01-01

In January 1997, after a lengthy, careful, and difficult process, an ad hoc group, chaired by Dr. Alan R. Fleischman, a Senior Vice President of the New York Academy of Medicine (NYAM), with representation from clinical medicine, biomedical ethics, law, and the clergy, developed a position on the difficult and contentious issue of physician-assisted suicide. After substantial debate, the Board of Trustees of NYAM authorized a letter from the President of the Academy to the Justices of the United States Supreme Court and to the attorneys on both sides of the cases about to be argued before the Court. The text of that letter, which summarizes the views of the New York Academy of Medicine, is reproduced here.