Sample records for priority based multicast

  1. Algorithm for protecting light-trees in survivable mesh wavelength-division-multiplexing networks

    NASA Astrophysics Data System (ADS)

    Luo, Hongbin; Li, Lemin; Yu, Hongfang

    2006-12-01

    Wavelength-division-multiplexing (WDM) technology is expected to facilitate bandwidth-intensive multicast applications such as high-definition television. A single fiber cut in a WDM mesh network, however, can disrupt the dissemination of information to several destinations on a light-tree based multicast session. Thus it is imperative to protect multicast sessions by reserving redundant resources. We propose a novel and efficient algorithm for protecting light-trees in survivable WDM mesh networks. The algorithm is called segment-based protection with sister node first (SSNF), whose basic idea is to protect a light-tree using a set of backup segments with a higher priority to protect the segments from a branch point to its children (sister nodes). The SSNF algorithm differs from the segment protection scheme proposed in the literature in how the segments are identified and protected. Our objective is to minimize the network resources used for protecting each primary light-tree such that the blocking probability can be minimized. To verify the effectiveness of the SSNF algorithm, we conduct extensive simulation experiments. The simulation results demonstrate that the SSNF algorithm outperforms existing algorithms for the same problem.

  2. 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.

  3. Maximization Network Throughput Based on Improved Genetic Algorithm and Network Coding for Optical Multicast Networks

    NASA Astrophysics Data System (ADS)

    Wei, Chengying; Xiong, Cuilian; Liu, Huanlin

    2017-12-01

    Maximal multicast stream algorithm based on network coding (NC) can improve the network's throughput for wavelength-division multiplexing (WDM) networks, which however is far less than the network's maximal throughput in terms of theory. And the existing multicast stream algorithms do not give the information distribution pattern and routing in the meantime. In the paper, an improved genetic algorithm is brought forward to maximize the optical multicast throughput by NC and to determine the multicast stream distribution by hybrid chromosomes construction for multicast with single source and multiple destinations. The proposed hybrid chromosomes are constructed by the binary chromosomes and integer chromosomes, while the binary chromosomes represent optical multicast routing and the integer chromosomes indicate the multicast stream distribution. A fitness function is designed to guarantee that each destination can receive the maximum number of decoding multicast streams. The simulation results showed that the proposed method is far superior over the typical maximal multicast stream algorithms based on NC in terms of network throughput in WDM networks.

  4. VMCast: A VM-Assisted Stability Enhancing Solution for Tree-Based Overlay Multicast

    PubMed Central

    Gu, Weidong; Zhang, Xinchang; Gong, Bin; Zhang, Wei; Wang, Lu

    2015-01-01

    Tree-based overlay multicast is an effective group communication method for media streaming applications. However, a group member’s departure causes all of its descendants to be disconnected from the multicast tree for some time, which results in poor performance. The above problem is difficult to be addressed because overlay multicast tree is intrinsically instable. In this paper, we proposed a novel stability enhancing solution, VMCast, for tree-based overlay multicast. This solution uses two types of on-demand cloud virtual machines (VMs), i.e., multicast VMs (MVMs) and compensation VMs (CVMs). MVMs are used to disseminate the multicast data, whereas CVMs are used to offer streaming compensation. The used VMs in the same cloud datacenter constitute a VM cluster. Each VM cluster is responsible for a service domain (VMSD), and each group member belongs to a specific VMSD. The data source delivers the multicast data to MVMs through a reliable path, and MVMs further disseminate the data to group members along domain overlay multicast trees. The above approach structurally improves the stability of the overlay multicast tree. We further utilized CVM-based streaming compensation to enhance the stability of the data distribution in the VMSDs. VMCast can be used as an extension to existing tree-based overlay multicast solutions, to provide better services for media streaming applications. We applied VMCast to two application instances (i.e., HMTP and HCcast). The results show that it can obviously enhance the stability of the data distribution. PMID:26562152

  5. VMCast: A VM-Assisted Stability Enhancing Solution for Tree-Based Overlay Multicast.

    PubMed

    Gu, Weidong; Zhang, Xinchang; Gong, Bin; Zhang, Wei; Wang, Lu

    2015-01-01

    Tree-based overlay multicast is an effective group communication method for media streaming applications. However, a group member's departure causes all of its descendants to be disconnected from the multicast tree for some time, which results in poor performance. The above problem is difficult to be addressed because overlay multicast tree is intrinsically instable. In this paper, we proposed a novel stability enhancing solution, VMCast, for tree-based overlay multicast. This solution uses two types of on-demand cloud virtual machines (VMs), i.e., multicast VMs (MVMs) and compensation VMs (CVMs). MVMs are used to disseminate the multicast data, whereas CVMs are used to offer streaming compensation. The used VMs in the same cloud datacenter constitute a VM cluster. Each VM cluster is responsible for a service domain (VMSD), and each group member belongs to a specific VMSD. The data source delivers the multicast data to MVMs through a reliable path, and MVMs further disseminate the data to group members along domain overlay multicast trees. The above approach structurally improves the stability of the overlay multicast tree. We further utilized CVM-based streaming compensation to enhance the stability of the data distribution in the VMSDs. VMCast can be used as an extension to existing tree-based overlay multicast solutions, to provide better services for media streaming applications. We applied VMCast to two application instances (i.e., HMTP and HCcast). The results show that it can obviously enhance the stability of the data distribution.

  6. Design of a Multicast Optical Packet Switch Based on Fiber Bragg Grating Technology for Future Networks

    NASA Astrophysics Data System (ADS)

    Cheng, Yuh-Jiuh; Yeh, Tzuoh-Chyau; Cheng, Shyr-Yuan

    2011-09-01

    In this paper, a non-blocking multicast optical packet switch based on fiber Bragg grating technology with optical output buffers is proposed. Only the header of optical packets is converted to electronic signals to control the fiber Bragg grating array of input ports and the packet payloads should be transparently destined to their output ports so that the proposed switch can reduce electronic interfaces as well as the bit rate. The modulation and the format of packet payloads may be non-standard where packet payloads could also include different wavelengths for increasing the volume of traffic. The advantage is obvious: the proposed switch could transport various types of traffic. An easily implemented architecture which can provide multicast services is also presented. An optical output buffer is designed to queue the packets if more than one incoming packet should reach to the same destination output port or including any waiting packets in optical output buffer that will be sent to the output port at a time slot. For preserving service-packet sequencing and fairness of routing sequence, a priority scheme and a round-robin algorithm are adopted at the optical output buffer. The fiber Bragg grating arrays for both input ports and output ports are designed for routing incoming packets using optical code division multiple access technology.

  7. A Stateful Multicast Access Control Mechanism for Future Metro-Area-Networks.

    ERIC Educational Resources Information Center

    Sun, Wei-qiang; Li, Jin-sheng; Hong, Pei-lin

    2003-01-01

    Multicasting is a necessity for a broadband metro-area-network; however security problems exist with current multicast protocols. A stateful multicast access control mechanism, based on MAPE, is proposed. The architecture of MAPE is discussed, as well as the states maintained and messages exchanged. The scheme is flexible and scalable. (Author/AEF)

  8. Protocol Architecture Model Report

    NASA Technical Reports Server (NTRS)

    Dhas, Chris

    2000-01-01

    NASA's Glenn Research Center (GRC) defines and develops advanced technology for high priority national needs in communications technologies for application to aeronautics and space. GRC tasked Computer Networks and Software Inc. (CNS) to examine protocols and architectures for an In-Space Internet Node. CNS has developed a methodology for network reference models to support NASA's four mission areas: Earth Science, Space Science, Human Exploration and Development of Space (REDS), Aerospace Technology. This report applies the methodology to three space Internet-based communications scenarios for future missions. CNS has conceptualized, designed, and developed space Internet-based communications protocols and architectures for each of the independent scenarios. The scenarios are: Scenario 1: Unicast communications between a Low-Earth-Orbit (LEO) spacecraft inspace Internet node and a ground terminal Internet node via a Tracking and Data Rela Satellite (TDRS) transfer; Scenario 2: Unicast communications between a Low-Earth-Orbit (LEO) International Space Station and a ground terminal Internet node via a TDRS transfer; Scenario 3: Multicast Communications (or "Multicasting"), 1 Spacecraft to N Ground Receivers, N Ground Transmitters to 1 Ground Receiver via a Spacecraft.

  9. Web server for priority ordered multimedia services

    NASA Astrophysics Data System (ADS)

    Celenk, Mehmet; Godavari, Rakesh K.; Vetnes, Vermund

    2001-10-01

    In this work, our aim is to provide finer priority levels in the design of a general-purpose Web multimedia server with provisions of the CM services. The type of services provided include reading/writing a web page, downloading/uploading an audio/video stream, navigating the Web through browsing, and interactive video teleconferencing. The selected priority encoding levels for such operations follow the order of admin read/write, hot page CM and Web multicasting, CM read, Web read, CM write and Web write. Hot pages are the most requested CM streams (e.g., the newest movies, video clips, and HDTV channels) and Web pages (e.g., portal pages of the commercial Internet search engines). Maintaining a list of these hot Web pages and CM streams in a content addressable buffer enables a server to multicast hot streams with lower latency and higher system throughput. Cold Web pages and CM streams are treated as regular Web and CM requests. Interactive CM operations such as pause (P), resume (R), fast-forward (FF), and rewind (RW) have to be executed without allocation of extra resources. The proposed multimedia server model is a part of the distributed network with load balancing schedulers. The SM is connected to an integrated disk scheduler (IDS), which supervises an allocated disk manager. The IDS follows the same priority handling as the SM, and implements a SCAN disk-scheduling method for an improved disk access and a higher throughput. Different disks are used for the Web and CM services in order to meet the QoS requirements of CM services. The IDS ouput is forwarded to an Integrated Transmission Scheduler (ITS). The ITS creates a priority ordered buffering of the retrieved Web pages and CM data streams that are fed into an auto regressive moving average (ARMA) based traffic shaping circuitry before being transmitted through the network.

  10. Mobility based key management technique for multicast security in mobile ad hoc networks.

    PubMed

    Madhusudhanan, B; Chitra, S; Rajan, C

    2015-01-01

    In MANET multicasting, forward and backward secrecy result in increased packet drop rate owing to mobility. Frequent rekeying causes large message overhead which increases energy consumption and end-to-end delay. Particularly, the prevailing group key management techniques cause frequent mobility and disconnections. So there is a need to design a multicast key management technique to overcome these problems. In this paper, we propose the mobility based key management technique for multicast security in MANET. Initially, the nodes are categorized according to their stability index which is estimated based on the link availability and mobility. A multicast tree is constructed such that for every weak node, there is a strong parent node. A session key-based encryption technique is utilized to transmit a multicast data. The rekeying process is performed periodically by the initiator node. The rekeying interval is fixed depending on the node category so that this technique greatly minimizes the rekeying overhead. By simulation results, we show that our proposed approach reduces the packet drop rate and improves the data confidentiality.

  11. Scalable Multicast Protocols for Overlapped Groups in Broker-Based Sensor Networks

    NASA Astrophysics Data System (ADS)

    Kim, Chayoung; Ahn, Jinho

    In sensor networks, there are lots of overlapped multicast groups because of many subscribers, associated with their potentially varying specific interests, querying every event to sensors/publishers. And gossip based communication protocols are promising as one of potential solutions providing scalability in P(Publish)/ S(Subscribe) paradigm in sensor networks. Moreover, despite the importance of both guaranteeing message delivery order and supporting overlapped multicast groups in sensor or P2P networks, there exist little research works on development of gossip-based protocols to satisfy all these requirements. In this paper, we present two versions of causally ordered delivery guaranteeing protocols for overlapped multicast groups. The one is based on sensor-broker as delegates and the other is based on local views and delegates representing subscriber subgroups. In the sensor-broker based protocol, sensor-broker might lead to make overlapped multicast networks organized by subscriber's interests. The message delivery order has been guaranteed consistently and all multicast messages are delivered to overlapped subscribers using gossip based protocols by sensor-broker. Therefore, these features of the sensor-broker based protocol might be significantly scalable rather than those of the protocols by hierarchical membership list of dedicated groups like traditional committee protocols. And the subscriber-delegate based protocol is much stronger rather than fully decentralized protocols guaranteeing causally ordered delivery based on only local views because the message delivery order has been guaranteed consistently by all corresponding members of the groups including delegates. Therefore, this feature of the subscriber-delegate protocol is a hybrid approach improving the inherent scalability of multicast nature by gossip-based technique in all communications.

  12. Demonstration of flexible and reconfigurable WDM multicast scheme supporting downstream emergency multicast communication for WDM optical access network

    NASA Astrophysics Data System (ADS)

    Li, Ze; Zhang, Min; Wang, Danshi; Cui, Yue

    2017-09-01

    We propose a flexible and reconfigurable wavelength-division multiplexing (WDM) multicast scheme supporting downstream emergency multicast communication for WDM optical access network (WDM-OAN) via a multicast module (MM) based on four-wave mixing (FWM) in a semiconductor optical amplifier. It serves as an emergency measure to dispose of the burst, large bandwidth, and real-time multicast service with fast service provisioning and high resource efficiency. It also plays the role of physical backup in cases of big data migration or network disaster caused by invalid lasers or modulator failures. It provides convenient and reliable multicast service and emergency protection for WDM-OAN without modifying WDM-OAN structure. The strategies of an MM setting at the optical line terminal and remote node are discussed to apply this scheme to passive optical networks and active optical networks, respectively. Utilizing the proposed scheme, we demonstrate a proof-of-concept experiment in which one-to-six/eight 10-Gbps nonreturn-to-zero-differential phase-shift keying WDM multicasts in both strategies are successfully transmitted over single-mode fiber of 20.2 km. One-to-many reconfigurable WDM multicasts dealing with higher data rate and other modulation formats of multicast service are possible through the proposed scheme. It can be applied to different WDM access technologies, e.g., time-wavelength-division multiplexing-OAN and coherent WDM-OAN, and upgraded smoothly.

  13. Link importance incorporated failure probability measuring solution for multicast light-trees in elastic optical networks

    NASA Astrophysics Data System (ADS)

    Li, Xin; Zhang, Lu; Tang, Ying; Huang, Shanguo

    2018-03-01

    The light-tree-based optical multicasting (LT-OM) scheme provides a spectrum- and energy-efficient method to accommodate emerging multicast services. Some studies focus on the survivability technologies for LTs against a fixed number of link failures, such as single-link failure. However, a few studies involve failure probability constraints when building LTs. It is worth noting that each link of an LT plays different important roles under failure scenarios. When calculating the failure probability of an LT, the importance of its every link should be considered. We design a link importance incorporated failure probability measuring solution (LIFPMS) for multicast LTs under independent failure model and shared risk link group failure model. Based on the LIFPMS, we put forward the minimum failure probability (MFP) problem for the LT-OM scheme. Heuristic approaches are developed to address the MFP problem in elastic optical networks. Numerical results show that the LIFPMS provides an accurate metric for calculating the failure probability of multicast LTs and enhances the reliability of the LT-OM scheme while accommodating multicast services.

  14. Design and implementation of priority and time-window based traffic scheduling and routing-spectrum allocation mechanism in elastic optical networks

    NASA Astrophysics Data System (ADS)

    Wang, Honghuan; Xing, Fangyuan; Yin, Hongxi; Zhao, Nan; Lian, Bizhan

    2016-02-01

    With the explosive growth of network services, the reasonable traffic scheduling and efficient configuration of network resources have an important significance to increase the efficiency of the network. In this paper, an adaptive traffic scheduling policy based on the priority and time window is proposed and the performance of this algorithm is evaluated in terms of scheduling ratio. The routing and spectrum allocation are achieved by using the Floyd shortest path algorithm and establishing a node spectrum resource allocation model based on greedy algorithm, which is proposed by us. The fairness index is introduced to improve the capability of spectrum configuration. The results show that the designed traffic scheduling strategy can be applied to networks with multicast and broadcast functionalities, and makes them get real-time and efficient response. The scheme of node spectrum configuration improves the frequency resource utilization and gives play to the efficiency of the network.

  15. Multicast routing for wavelength-routed WDM networks with dynamic membership

    NASA Astrophysics Data System (ADS)

    Huang, Nen-Fu; Liu, Te-Lung; Wang, Yao-Tzung; Li, Bo

    2000-09-01

    Future broadband networks must support integrated services and offer flexible bandwidth usage. In our previous work, we explore the optical link control layer on the top of optical layer that enables the possibility of bandwidth on-demand service directly over wavelength division multiplexed (WDM) networks. Today, more and more applications and services such as video-conferencing software and Virtual LAN service require multicast support over the underlying networks. Currently, it is difficult to provide wavelength multicast over the optical switches without optical/electronic conversions although the conversion takes extra cost. In this paper, based on the proposed wavelength router architecture (equipped with ATM switches to offer O/E and E/O conversions when necessary), a dynamic multicast routing algorithm is proposed to furnish multicast services over WDM networks. The goal is to joint a new group member into the multicast tree so that the cost, including the link cost and the optical/electronic conversion cost, is kept as less as possible. The effectiveness of the proposed wavelength router architecture as well as the dynamic multicast algorithm is evaluated by simulation.

  16. Group-multicast capable optical virtual private ring with contention avoidance

    NASA Astrophysics Data System (ADS)

    Peng, Yunfeng; Du, Shu; Long, Keping

    2008-11-01

    A ring based optical virtual private network (OVPN) employing contention sensing and avoidance is proposed to deliver multiple-to-multiple group-multicast traffic. The network architecture is presented and its operation principles as well as performance are investigated. The main contribution of this article is the presentation of an innovative group-multicast capable OVPN architecture with technologies available today.

  17. Dynamic multicast routing scheme in WDM optical network

    NASA Astrophysics Data System (ADS)

    Zhu, Yonghua; Dong, Zhiling; Yao, Hong; Yang, Jianyong; Liu, Yibin

    2007-11-01

    During the information era, the Internet and the service of World Wide Web develop rapidly. Therefore, the wider and wider bandwidth is required with the lower and lower cost. The demand of operation turns out to be diversified. Data, images, videos and other special transmission demands share the challenge and opportunity with the service providers. Simultaneously, the electrical equipment has approached their limit. So the optical communication based on the wavelength division multiplexing (WDM) and the optical cross-connects (OXCs) shows great potentials and brilliant future to build an optical network based on the unique technical advantage and multi-wavelength characteristic. In this paper, we propose a multi-layered graph model with inter-path between layers to solve the problem of multicast routing wavelength assignment (RWA) contemporarily by employing an efficient graph theoretic formulation. And at the same time, an efficient dynamic multicast algorithm named Distributed Message Copying Multicast (DMCM) mechanism is also proposed. The multicast tree with minimum hops can be constructed dynamically according to this proposed scheme.

  18. Simultaneous multichannel wavelength multicasting and XOR logic gate multicasting for three DPSK signals based on four-wave mixing in quantum-dot semiconductor optical amplifier.

    PubMed

    Qin, Jun; Lu, Guo-Wei; Sakamoto, Takahide; Akahane, Kouichi; Yamamoto, Naokatsu; Wang, Danshi; Wang, Cheng; Wang, Hongxiang; Zhang, Min; Kawanishi, Tetsuya; Ji, Yuefeng

    2014-12-01

    In this paper, we experimentally demonstrate simultaneous multichannel wavelength multicasting (MWM) and exclusive-OR logic gate multicasting (XOR-LGM) for three 10Gbps non-return-to-zero differential phase-shift-keying (NRZ-DPSK) signals in quantum-dot semiconductor optical amplifier (QD-SOA) by exploiting the four-wave mixing (FWM) process. No additional pump is needed in the scheme. Through the interaction of the input three 10Gbps DPSK signal lights in QD-SOA, each channel is successfully multicasted to three wavelengths (1-to-3 for each), totally 3-to-9 MWM, and at the same time, three-output XOR-LGM is obtained at three different wavelengths. All the new generated channels are with a power penalty less than 1.2dB at a BER of 10(-9). Degenerate and non-degenerate FWM components are fully used in the experiment for data and logic multicasting.

  19. The Verification-based Analysis of Reliable Multicast Protocol

    NASA Technical Reports Server (NTRS)

    Wu, Yunqing

    1996-01-01

    Reliable Multicast Protocol (RMP) is a communication protocol that provides an atomic, totally ordered, reliable multicast service on top of unreliable IP Multicasting. In this paper, we develop formal models for R.W using existing automatic verification systems, and perform verification-based analysis on the formal RMP specifications. We also use the formal models of RW specifications to generate a test suite for conformance testing of the RMP implementation. Throughout the process of RMP development, we follow an iterative, interactive approach that emphasizes concurrent and parallel progress between the implementation and verification processes. Through this approach, we incorporate formal techniques into our development process, promote a common understanding for the protocol, increase the reliability of our software, and maintain high fidelity between the specifications of RMP and its implementation.

  20. Multifunctional switching unit for add/drop, wavelength conversion, format conversion, and WDM multicast based on bidirectional LCoS and SOA-loop architecture.

    PubMed

    Wang, Danshi; Zhang, Min; Qin, Jun; Lu, Guo-Wei; Wang, Hongxiang; Huang, Shanguo

    2014-09-08

    We propose a multifunctional optical switching unit based on the bidirectional liquid crystal on silicon (LCoS) and semiconductor optical amplifier (SOA) architecture. Add/drop, wavelength conversion, format conversion, and WDM multicast are experimentally demonstrated. Due to the bidirectional characteristic, the LCoS device cannot only multiplex the input signals, but also de-multiplex the converted signals. Dual-channel wavelength conversion and format conversion from 2 × 25Gbps differential quadrature phase-shift-keying (DQPSK) to 2 × 12.5Gbps differential phase-shift-keying (DPSK) based on four-wave mixing (FWM) in SOA is obtained with only one pump. One-to-six WDM multicast of 25Gbps DQPSK signals with two pumps is also achieved. All of the multicast channels are with a power penalty less than 1.1 dB at FEC threshold of 3.8 × 10⁻³.

  1. Dynamic segment shared protection for multicast traffic in meshed wavelength-division-multiplexing optical networks

    NASA Astrophysics Data System (ADS)

    Liao, Luhua; Li, Lemin; Wang, Sheng

    2006-12-01

    We investigate the protection approach for dynamic multicast traffic under shared risk link group (SRLG) constraints in meshed wavelength-division-multiplexing optical networks. We present a shared protection algorithm called dynamic segment shared protection for multicast traffic (DSSPM), which can dynamically adjust the link cost according to the current network state and can establish a primary light-tree as well as corresponding SRLG-disjoint backup segments for a dependable multicast connection. A backup segment can efficiently share the wavelength capacity of its working tree and the common resources of other backup segments based on SRLG-disjoint constraints. The simulation results show that DSSPM not only can protect the multicast sessions against a single-SRLG breakdown, but can make better use of the wavelength resources and also lower the network blocking probability.

  2. Evaluation of multicast schemes in optical burst-switched networks: the case with dynamic sessions

    NASA Astrophysics Data System (ADS)

    Jeong, Myoungki; Qiao, Chunming; Xiong, Yijun; Vandenhoute, Marc

    2000-10-01

    In this paper, we evaluate the performance of several multicast schemes in optical burst-switched WDM networks taking into accounts the overheads due to control packets and guard bands (Gbs) of bursts on separate channels (wavelengths). A straightforward scheme is called Separate Multicasting (S-MCAST) where each source node constructs separate bursts for its multicast (per each multicast session) and unicast traffic. To reduce the overhead due to Gbs (and control packets), one may piggyback the multicast traffic in bursts containing unicast traffic using a scheme called Multiple Unicasting (M-UCAST). The third scheme is called Tree-Shared Multicasting (TS-MCAST) wehreby multicast traffic belonging to multiple multicast sesions can be mixed together in a burst, which is delivered via a shared multicast tree. In [1], we have evaluated several multicast schemes with static sessions at the flow level. In this paper, we perform a simple analysis for the multicast schemes and evaluate the performance of three multicast schemes, focusing on the case with dynamic sessions in terms of the link utilization, bandwidth consumption, blocking (loss) probability, goodput and the processing loads.

  3. Multicast backup reprovisioning problem for Hamiltonian cycle-based protection on WDM networks

    NASA Astrophysics Data System (ADS)

    Din, Der-Rong; Huang, Jen-Shen

    2014-03-01

    As networks grow in size and complexity, the chance and the impact of failures increase dramatically. The pre-allocated backup resources cannot provide 100% protection guarantee when continuous failures occur in a network. In this paper, the multicast backup re-provisioning problem (MBRP) for Hamiltonian cycle (HC)-based protection on WDM networks for the link-failure case is studied. We focus on how to recover the protecting capabilities of Hamiltonian cycle against the subsequent link-failures on WDM networks for multicast transmissions, after recovering the multicast trees affected by the previous link-failure. Since this problem is a hard problem, an algorithm, which consists of several heuristics and a genetic algorithm (GA), is proposed to solve it. The simulation results of the proposed method are also given. Experimental results indicate that the proposed algorithm can solve this problem efficiently.

  4. Near-field self-interference cancellation and quality of service multicast beamforming in full-duplex

    NASA Astrophysics Data System (ADS)

    Wu, Fei; Shao, Shihai; Tang, Youxi

    2016-10-01

    To enable simultaneous multicast downlink transmit and receive operations on the same frequency band, also known as full-duplex links between an access point and mobile users. The problem of minimizing the total power of multicast transmit beamforming is considered from the viewpoint of ensuring the suppression amount of near-field line-of-sight self-interference and guaranteeing prescribed minimum signal-to-interference-plus-noise-ratio (SINR) at each receiver of the multicast groups. Based on earlier results for multicast groups beamforming, the joint problem is easily shown to be NP-hard. A semidefinite relaxation (SDR) technique with linear program power adjust method is proposed to solve the NP-hard problem. Simulation shows that the proposed method is feasible even when the local receive antenna in nearfield and the mobile user in far-filed are in the same direction.

  5. Authenticated IGMP for Controlling Access to Multicast Distribution Tree

    NASA Astrophysics Data System (ADS)

    Park, Chang-Seop; Kang, Hyun-Sun

    A receiver access control scheme is proposed to protect the multicast distribution tree from DoS attack induced by unauthorized use of IGMP, by extending the security-related functionality of IGMP. Based on a specific network and business model adopted for commercial deployment of IP multicast applications, a key management scheme is also presented for bootstrapping the proposed access control as well as accounting and billing for CP (Content Provider), NSP (Network Service Provider), and group members.

  6. A decentralized software bus based on IP multicas ting

    NASA Technical Reports Server (NTRS)

    Callahan, John R.; Montgomery, Todd

    1995-01-01

    We describe decentralized reconfigurable implementation of a conference management system based on the low-level Internet Protocol (IP) multicasting protocol. IP multicasting allows low-cost, world-wide, two-way transmission of data between large numbers of conferencing participants through the Multicasting Backbone (MBone). Each conference is structured as a software bus -- a messaging system that provides a run-time interconnection model that acts as a separate agent (i.e., the bus) for routing, queuing, and delivering messages between distributed programs. Unlike the client-server interconnection model, the software bus model provides a level of indirection that enhances the flexibility and reconfigurability of a distributed system. Current software bus implementations like POLYLITH, however, rely on a centralized bus process and point-to-point protocols (i.e., TCP/IP) to route, queue, and deliver messages. We implement a software bus called the MULTIBUS that relies on a separate process only for routing and uses a reliable IP multicasting protocol for delivery of messages. The use of multicasting means that interconnections are independent of IP machine addresses. This approach allows reconfiguration of bus participants during system execution without notifying other participants of new IP addresses. The use of IP multicasting also permits an economy of scale in the number of participants. We describe the MULITIBUS protocol elements and show how our implementation performs better than centralized bus implementations.

  7. Mobility based multicast routing in wireless mesh networks

    NASA Astrophysics Data System (ADS)

    Jain, Sanjeev; Tripathi, Vijay S.; Tiwari, Sudarshan

    2013-01-01

    There exist two fundamental approaches to multicast routing namely minimum cost trees and shortest path trees. The (MCT's) minimum cost tree is one which connects receiver and sources by providing a minimum number of transmissions (MNTs) the MNTs approach is generally used for energy constraint sensor and mobile ad hoc networks. In this paper we have considered node mobility and try to find out simulation based comparison of the (SPT's) shortest path tree, (MST's) minimum steiner trees and minimum number of transmission trees in wireless mesh networks by using the performance metrics like as an end to end delay, average jitter, throughput and packet delivery ratio, average unicast packet delivery ratio, etc. We have also evaluated multicast performance in the small and large wireless mesh networks. In case of multicast performance in the small networks we have found that when the traffic load is moderate or high the SPTs outperform the MSTs and MNTs in all cases. The SPTs have lowest end to end delay and average jitter in almost all cases. In case of multicast performance in the large network we have seen that the MSTs provide minimum total edge cost and minimum number of transmissions. We have also found that the one drawback of SPTs, when the group size is large and rate of multicast sending is high SPTs causes more packet losses to other flows as MCTs.

  8. The specification-based validation of reliable multicast protocol: Problem Report. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Wu, Yunqing

    1995-01-01

    Reliable Multicast Protocol (RMP) is a communication protocol that provides an atomic, totally ordered, reliable multicast service on top of unreliable IP multicasting. In this report, we develop formal models for RMP using existing automated verification systems, and perform validation on the formal RMP specifications. The validation analysis help identifies some minor specification and design problems. We also use the formal models of RMP to generate a test suite for conformance testing of the implementation. Throughout the process of RMP development, we follow an iterative, interactive approach that emphasizes concurrent and parallel progress of implementation and verification processes. Through this approach, we incorporate formal techniques into our development process, promote a common understanding for the protocol, increase the reliability of our software, and maintain high fidelity between the specifications of RMP and its implementation.

  9. Fixed-rate layered multicast congestion control

    NASA Astrophysics Data System (ADS)

    Bing, Zhang; Bing, Yuan; Zengji, Liu

    2006-10-01

    A new fixed-rate layered multicast congestion control algorithm called FLMCC is proposed. The sender of a multicast session transmits data packets at a fixed rate on each layer, while receivers each obtain different throughput by cumulatively subscribing to deferent number of layers based on their expected rates. In order to provide TCP-friendliness and estimate the expected rate accurately, a window-based mechanism implemented at receivers is presented. To achieve this, each receiver maintains a congestion window, adjusts it based on the GAIMD algorithm, and from the congestion window an expected rate is calculated. To measure RTT, a new method is presented which combines an accurate measurement with a rough estimation. A feedback suppression based on a random timer mechanism is given to avoid feedback implosion in the accurate measurement. The protocol is simple in its implementation. Simulations indicate that FLMCC shows good TCP-friendliness, responsiveness as well as intra-protocol fairness, and provides high link utilization.

  10. Multicasting based optical inverse multiplexing in elastic optical network.

    PubMed

    Guo, Bingli; Xu, Yingying; Zhu, Paikun; Zhong, Yucheng; Chen, Yuanxiang; Li, Juhao; Chen, Zhangyuan; He, Yongqi

    2014-06-16

    Optical multicasting based inverse multiplexing (IM) is introduced in spectrum allocation of elastic optical network to resolve the spectrum fragmentation problem, where superchannels could be split and fit into several discrete spectrum blocks in the intermediate node. We experimentally demonstrate it with a 1-to-7 optical superchannel multicasting module and selecting/coupling components. Also, simulation results show that, comparing with several emerging spectrum defragmentation solutions (e.g., spectrum conversion, split spectrum), IM could reduce blocking performance significantly but without adding too much system complexity as split spectrum. On the other hand, service fairness for traffic with different granularity of these schemes is investigated for the first time and it shows that IM performs better than spectrum conversion and almost as well as split spectrum, especially for smaller size traffic under light traffic intensity.

  11. Reliable multicast protocol specifications flow control and NACK policy

    NASA Technical Reports Server (NTRS)

    Callahan, John R.; Montgomery, Todd L.; Whetten, Brian

    1995-01-01

    This appendix presents the flow and congestion control schemes recommended for RMP and a NACK policy based on the whiteboard tool. Because RMP uses a primarily NACK based error detection scheme, there is no direct feedback path through which receivers can signal losses through low buffer space or congestion. Reliable multicast protocols also suffer from the fact that throughput for a multicast group must be divided among the members of the group. This division is usually very dynamic in nature and therefore does not lend itself well to a priori determination. These facts have led the flow and congestion control schemes of RMP to be made completely orthogonal to the protocol specification. This allows several differing schemes to be used in different environments to produce the best results. As a default, a modified sliding window scheme based on previous algorithms are suggested and described below.

  12. Degree-constrained multicast routing for multimedia communications

    NASA Astrophysics Data System (ADS)

    Wang, Yanlin; Sun, Yugeng; Li, Guidan

    2005-02-01

    Multicast services have been increasingly used by many multimedia applications. As one of the key techniques to support multimedia applications, the rational and effective multicast routing algorithms are very important to networks performance. When switch nodes in networks have different multicast capability, multicast routing problem is modeled as the degree-constrained Steiner problem. We presented two heuristic algorithms, named BMSTA and BSPTA, for the degree-constrained case in multimedia communications. Both algorithms are used to generate degree-constrained multicast trees with bandwidth and end to end delay bound. Simulations over random networks were carried out to compare the performance of the two proposed algorithms. Experimental results show that the proposed algorithms have advantages in traffic load balancing, which can avoid link blocking and enhance networks performance efficiently. BMSTA has better ability in finding unsaturated links and (or) unsaturated nodes to generate multicast trees than BSPTA. The performance of BMSTA is affected by the variation of degree constraints.

  13. A proposed group management scheme for XTP multicast

    NASA Technical Reports Server (NTRS)

    Dempsey, Bert J.; Weaver, Alfred C.

    1990-01-01

    The purpose of a group management scheme is to enable its associated transfer layer protocol to be responsive to user determined reliability requirements for multicasting. Group management (GM) must assist the client process in coordinating multicast group membership, allow the user to express the subset of the multicast group that a particular multicast distribution must reach in order to be successful (reliable), and provide the transfer layer protocol with the group membership information necessary to guarantee delivery to this subset. GM provides services and mechanisms that respond to the need of the client process or process level management protocols to coordinate, modify, and determine attributes of the multicast group, especially membership. XTP GM provides a link between process groups and their multicast groups by maintaining a group membership database that identifies members in a name space understood by the underlying transfer layer protocol. Other attributes of the multicast group useful to both the client process and the data transfer protocol may be stored in the database. Examples include the relative dispersion, most recent update, and default delivery parameters of a group.

  14. Optical multicast system for data center networks.

    PubMed

    Samadi, Payman; Gupta, Varun; Xu, Junjie; Wang, Howard; Zussman, Gil; Bergman, Keren

    2015-08-24

    We present the design and experimental evaluation of an Optical Multicast System for Data Center Networks, a hardware-software system architecture that uniquely integrates passive optical splitters in a hybrid network architecture for faster and simpler delivery of multicast traffic flows. An application-driven control plane manages the integrated optical and electronic switched traffic routing in the data plane layer. The control plane includes a resource allocation algorithm to optimally assign optical splitters to the flows. The hardware architecture is built on a hybrid network with both Electronic Packet Switching (EPS) and Optical Circuit Switching (OCS) networks to aggregate Top-of-Rack switches. The OCS is also the connectivity substrate of splitters to the optical network. The optical multicast system implementation requires only commodity optical components. We built a prototype and developed a simulation environment to evaluate the performance of the system for bulk multicasting. Experimental and numerical results show simultaneous delivery of multicast flows to all receivers with steady throughput. Compared to IP multicast that is the electronic counterpart, optical multicast performs with less protocol complexity and reduced energy consumption. Compared to peer-to-peer multicast methods, it achieves at minimum an order of magnitude higher throughput for flows under 250 MB with significantly less connection overheads. Furthermore, for delivering 20 TB of data containing only 15% multicast flows, it reduces the total delivery energy consumption by 50% and improves latency by 55% compared to a data center with a sole non-blocking EPS network.

  15. A novel WDM passive optical network architecture supporting two independent multicast data streams

    NASA Astrophysics Data System (ADS)

    Qiu, Yang; Chan, Chun-Kit

    2012-01-01

    We propose a novel scheme to perform optical multicast overlay of two independent multicast data streams on a wavelength-division-multiplexed (WDM) passive optical network. By controlling a sinusoidal clock signal and shifting the wavelength at the optical line terminal (OLT), the delivery of the two multicast data, being carried by the generated optical tones, can be independently and flexibly controlled. Simultaneous transmission of 10-Gb/s unicast downstream and upstream data as well as two independent 10-Gb/s multicast data was successfully demonstrated.

  16. Multipoint to multipoint routing and wavelength assignment in multi-domain optical networks

    NASA Astrophysics Data System (ADS)

    Qin, Panke; Wu, Jingru; Li, Xudong; Tang, Yongli

    2018-01-01

    In multi-point to multi-point (MP2MP) routing and wavelength assignment (RWA) problems, researchers usually assume the optical networks to be a single domain. However, the optical networks develop toward to multi-domain and larger scale in practice. In this context, multi-core shared tree (MST)-based MP2MP RWA are introduced problems including optimal multicast domain sequence selection, core nodes belonging in which domains and so on. In this letter, we focus on MST-based MP2MP RWA problems in multi-domain optical networks, mixed integer linear programming (MILP) formulations to optimally construct MP2MP multicast trees is presented. A heuristic algorithm base on network virtualization and weighted clustering algorithm (NV-WCA) is proposed. Simulation results show that, under different traffic patterns, the proposed algorithm achieves significant improvement on network resources occupation and multicast trees setup latency in contrast with the conventional algorithms which were proposed base on a single domain network environment.

  17. Enabling end-user network monitoring via the multicast consolidated proxy monitor

    NASA Astrophysics Data System (ADS)

    Kanwar, Anshuman; Almeroth, Kevin C.; Bhattacharyya, Supratik; Davy, Matthew

    2001-07-01

    The debugging of problems in IP multicast networks relies heavily on an eclectic set of stand-alone tools. These tools traditionally neither provide a consistent interface nor do they generate readily interpretable results. We propose the ``Multicast Consolidated Proxy Monitor''(MCPM), an integrated system for collecting, analyzing and presenting multicast monitoring results to both the end user and the network operator at the user's Internet Service Provider (ISP). The MCPM accesses network state information not normally visible to end users and acts as a proxy for disseminating this information. Functionally, through this architecture, we aim to a) provide a view of the multicast network at varying levels of granularity, b) provide end users with a limited ability to query the multicast infrastructure in real time, and c) protect the infrastructure from overwhelming amount of monitoring load through load control. Operationally, our scheme allows scaling to the ISPs dimensions, adaptability to new protocols (introduced as multicast evolves), threshold detection for crucial parameters and an access controlled, customizable interface design. Although the multicast scenario is used to illustrate the benefits of consolidated monitoring, the ultimate aim is to scale the scheme to unicast IP networks.

  18. A Secure Multicast Framework in Large and High-Mobility Network Groups

    NASA Astrophysics Data System (ADS)

    Lee, Jung-San; Chang, Chin-Chen

    With the widespread use of Internet applications such as Teleconference, Pay-TV, Collaborate tasks, and Message services, how to construct and distribute the group session key to all group members securely is becoming and more important. Instead of adopting the point-to-point packet delivery, these emerging applications are based upon the mechanism of multicast communication, which allows the group member to communicate with multi-party efficiently. There are two main issues in the mechanism of multicast communication: Key Distribution and Scalability. The first issue is how to distribute the group session key to all group members securely. The second one is how to maintain the high performance in large network groups. Group members in conventional multicast systems have to keep numerous secret keys in databases, which makes it very inconvenient for them. Furthermore, in case that a member joins or leaves the communication group, many involved participants have to change their own secret keys to preserve the forward secrecy and the backward secrecy. We consequently propose a novel version for providing secure multicast communication in large network groups. Our proposed framework not only preserves the forward secrecy and the backward secrecy but also possesses better performance than existing alternatives. Specifically, simulation results demonstrate that our scheme is suitable for high-mobility environments.

  19. Issues in designing transport layer multicast facilities

    NASA Technical Reports Server (NTRS)

    Dempsey, Bert J.; Weaver, Alfred C.

    1990-01-01

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

  20. Agile multicasting based on cascaded χ(2) nonlinearities in a step-chirped periodically poled lithium niobate.

    PubMed

    Ahlawat, Meenu; Bostani, Ameneh; Tehranchi, Amirhossein; Kashyap, Raman

    2013-08-01

    We experimentally demonstrate the possibility of agile multicasting for wavelength division multiplexing (WDM) networks, of a single-channel to two and seven channels over the C band, also extendable to S and L bands. This is based on cascaded χ(2) nonlinear mixing processes, namely, second-harmonic generation (SHG)-sum-frequency generation (SFG) and difference-frequency generation (DFG) in a 20-mm-long step-chirped periodically poled lithium niobate crystal, specially designed and fabricated for a 28-nm-wide SH-SF bandwidth centered at around 1.55 μm. The multiple idlers are simultaneously tuned by detuning the pump wavelengths within the broad SH-SF bandwidth. By selectively tuning the pump wavelengths over less than 10 and 6 nm, respectively, multicasting into two and seven idlers is successfully achieved across ~70 WDM channels within the 50 GHz International Telecommunication Union grid spacing.

  1. Application Layer Multicast

    NASA Astrophysics Data System (ADS)

    Allani, Mouna; Garbinato, Benoît; Pedone, Fernando

    An increasing number of Peer-to-Peer (P2P) Internet applications rely today on data dissemination as their cornerstone, e.g., audio or video streaming, multi-party games. These applications typically depend on some support for multicast communication, where peers interested in a given data stream can join a corresponding multicast group. As a consequence, the efficiency, scalability, and reliability guarantees of these applications are tightly coupled with that of the underlying multicast mechanism.

  2. A reliable multicast for XTP

    NASA Technical Reports Server (NTRS)

    Dempsey, Bert J.; Weaver, Alfred C.

    1990-01-01

    Multicast services needed for current distributed applications on LAN's fall generally into one of three categories: datagram, semi-reliable, and reliable. Transport layer multicast datagrams represent unreliable service in which the transmitting context 'fires and forgets'. XTP executes these semantics when the MULTI and NOERR mode bits are both set. Distributing sensor data and other applications in which application-level error recovery strategies are appropriate benefit from the efficiency in multidestination delivery offered by datagram service. Semi-reliable service refers to multicasting in which the control algorithms of the transport layer--error, flow, and rate control--are used in transferring the multicast distribution to the set of receiving contexts, the multicast group. The multicast defined in XTP provides semi-reliable service. Since, under a semi-reliable service, joining a multicast group means listening on the group address and entails no coordination with other members, a semi-reliable facility can be used for communication between a client and a server group as well as true peer-to-peer group communication. Resource location in a LAN is an important application domain. The term 'semi-reliable' refers to the fact that group membership changes go undetected. No attempt is made to assess the current membership of the group at any time--before, during, or after--the data transfer.

  3. Issues in providing a reliable multicast facility

    NASA Technical Reports Server (NTRS)

    Dempsey, Bert J.; Strayer, W. Timothy; Weaver, Alfred C.

    1990-01-01

    Issues involved in point-to-multipoint communication are presented and the literature for proposed solutions and approaches surveyed. Particular attention is focused on the ideas and implementations that align with the requirements of the environment of interest. The attributes of multicast receiver groups that might lead to useful classifications, what the functionality of a management scheme should be, and how the group management module can be implemented are examined. The services that multicasting facilities can offer are presented, followed by mechanisms within the communications protocol that implements these services. The metrics of interest when evaluating a reliable multicast facility are identified and applied to four transport layer protocols that incorporate reliable multicast.

  4. Simultaneous Wireless Power Transfer and Secure Multicasting in Cooperative Decode-and-Forward Relay Networks.

    PubMed

    Lee, Jong-Ho; Sohn, Illsoo; Kim, Yong-Hwa

    2017-05-16

    In this paper, we investigate simultaneous wireless power transfer and secure multicasting via cooperative decode-and-forward (DF) relays in the presence of multiple energy receivers and eavesdroppers. Two scenarios are considered under a total power budget: maximizing the minimum harvested energy among the energy receivers under a multicast secrecy rate constraint; and maximizing the multicast secrecy rate under a minimum harvested energy constraint. For both scenarios, we solve the transmit power allocation and relay beamformer design problems by using semidefinite relaxation and bisection technique. We present numerical results to analyze the energy harvesting and secure multicasting performances in cooperative DF relay networks.

  5. Simultaneous Wireless Power Transfer and Secure Multicasting in Cooperative Decode-and-Forward Relay Networks

    PubMed Central

    Lee, Jong-Ho; Sohn, Illsoo; Kim, Yong-Hwa

    2017-01-01

    In this paper, we investigate simultaneous wireless power transfer and secure multicasting via cooperative decode-and-forward (DF) relays in the presence of multiple energy receivers and eavesdroppers. Two scenarios are considered under a total power budget: maximizing the minimum harvested energy among the energy receivers under a multicast secrecy rate constraint; and maximizing the multicast secrecy rate under a minimum harvested energy constraint. For both scenarios, we solve the transmit power allocation and relay beamformer design problems by using semidefinite relaxation and bisection technique. We present numerical results to analyze the energy harvesting and secure multicasting performances in cooperative DF relay networks. PMID:28509841

  6. A Low-Complexity Subgroup Formation with QoS-Aware for Enhancing Multicast Services in LTE Networks

    NASA Astrophysics Data System (ADS)

    Algharem, M.; Omar, M. H.; Rahmat, R. F.; Budiarto, R.

    2018-03-01

    The high demand of Multimedia services on in Long Term Evolution (LTE) and beyond networks forces the networks operators to find a solution that can handle the huge traffic. Along with this, subgroup formation techniques are introduced to overcome the limitations of the Conventional Multicast Scheme (CMS) by splitting the multicast users into several subgroups based on the users’ channels quality signal. However, finding the best subgroup configuration with low complexity is need more investigations. In this paper, an efficient and simple subgroup formation mechanisms are proposed. The proposed mechanisms take the transmitter MAC queue in account. The effectiveness of the proposed mechanisms is evaluated and compared with CMS in terms of throughput, fairness, delay, Block Error Rate (BLER).

  7. Mobile Multicast in Hierarchical Proxy Mobile IPV6

    NASA Astrophysics Data System (ADS)

    Hafizah Mohd Aman, Azana; Hashim, Aisha Hassan A.; Mustafa, Amin; Abdullah, Khaizuran

    2013-12-01

    Mobile Internet Protocol Version 6 (MIPv6) environments have been developing very rapidly. Many challenges arise with the fast progress of MIPv6 technologies and its environment. Therefore the importance of improving the existing architecture and operations increases. One of the many challenges which need to be addressed is the need for performance improvement to support mobile multicast. Numerous approaches have been proposed to improve mobile multicast performance. This includes Context Transfer Protocol (CXTP), Hierarchical Mobile IPv6 (HMIPv6), Fast Mobile IPv6 (FMIPv6) and Proxy Mobile IPv6 (PMIPv6). This document describes multicast context transfer in hierarchical proxy mobile IPv6 (H-PMIPv6) to provide better multicasting performance in PMIPv6 domain.

  8. Efficient Group Coordination in Multicast Trees

    DTIC Science & Technology

    2001-01-01

    describe a novel protocol to coordinate multipoint groupwork within the IP-multicast framework. The protocol supports Internet-wide coordination for large...and highly-interactive groupwork , relying on the dissemination of coordination directives among group members across a shared end-to-end multicast

  9. Bulk data transfer distributer: a high performance multicast model in ALMA ACS

    NASA Astrophysics Data System (ADS)

    Cirami, R.; Di Marcantonio, P.; Chiozzi, G.; Jeram, B.

    2006-06-01

    A high performance multicast model for the bulk data transfer mechanism in the ALMA (Atacama Large Millimeter Array) Common Software (ACS) is presented. The ALMA astronomical interferometer will consist of at least 50 12-m antennas operating at millimeter wavelength. The whole software infrastructure for ALMA is based on ACS, which is a set of application frameworks built on top of CORBA. To cope with the very strong requirements for the amount of data that needs to be transported by the software communication channels of the ALMA subsystems (a typical output data rate expected from the Correlator is of the order of 64 MB per second) and with the potential CORBA bottleneck due to parameter marshalling/de-marshalling, usage of IIOP protocol, etc., a transfer mechanism based on the ACE/TAO CORBA Audio/Video (A/V) Streaming Service has been developed. The ACS Bulk Data Transfer architecture bypasses the CORBA protocol with an out-of-bound connection for the data streams (transmitting data directly in TCP or UDP format), using at the same time CORBA for handshaking and leveraging the benefits of ACS middleware. Such a mechanism has proven to be capable of high performances, of the order of 800 Mbits per second on a 1Gbit Ethernet network. Besides a point-to-point communication model, the ACS Bulk Data Transfer provides a multicast model. Since the TCP protocol does not support multicasting and all the data must be correctly delivered to all ALMA subsystems, a distributer mechanism has been developed. This paper focuses on the ACS Bulk Data Distributer, which mimics a multicast behaviour managing data dispatching to all receivers willing to get data from the same sender.

  10. WDM Network and Multicasting Protocol Strategies

    PubMed Central

    Zaim, Abdul Halim

    2014-01-01

    Optical technology gains extensive attention and ever increasing improvement because of the huge amount of network traffic caused by the growing number of internet users and their rising demands. However, with wavelength division multiplexing (WDM), it is easier to take the advantage of optical networks and optical burst switching (OBS) and to construct WDM networks with low delay rates and better data transparency these technologies are the best choices. Furthermore, multicasting in WDM is an urgent solution for bandwidth-intensive applications. In the paper, a new multicasting protocol with OBS is proposed. The protocol depends on a leaf initiated structure. The network is composed of source, ingress switches, intermediate switches, edge switches, and client nodes. The performance of the protocol is examined with Just Enough Time (JET) and Just In Time (JIT) reservation protocols. Also, the paper involves most of the recent advances about WDM multicasting in optical networks. WDM multicasting in optical networks is given as three common subtitles: Broadcast and-select networks, wavelength-routed networks, and OBS networks. Also, in the paper, multicast routing protocols are briefly summarized and optical burst switched WDM networks are investigated with the proposed multicast schemes. PMID:24744683

  11. Lightweight causal and atomic group multicast

    NASA Technical Reports Server (NTRS)

    Birman, Kenneth P.; Schiper, Andre; Stephenson, Pat

    1991-01-01

    The ISIS toolkit is a distributed programming environment based on support for virtually synchronous process groups and group communication. A suite of protocols is presented to support this model. The approach revolves around a multicast primitive, called CBCAST, which implements a fault-tolerant, causally ordered message delivery. This primitive can be used directly or extended into a totally ordered multicast primitive, called ABCAST. It normally delivers messages immediately upon reception, and imposes a space overhead proportional to the size of the groups to which the sender belongs, usually a small number. It is concluded that process groups and group communication can achieve performance and scaling comparable to that of a raw message transport layer. This finding contradicts the widespread concern that this style of distributed computing may be unacceptably costly.

  12. Point-to-Point Multicast Communications Protocol

    NASA Technical Reports Server (NTRS)

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

    1987-01-01

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

  13. High-Performance, Reliable Multicasting: Foundations for Future Internet Groupware Applications

    NASA Technical Reports Server (NTRS)

    Callahan, John; Montgomery, Todd; Whetten, Brian

    1997-01-01

    Network protocols that provide efficient, reliable, and totally-ordered message delivery to large numbers of users will be needed to support many future Internet applications. The Reliable Multicast Protocol (RMP) is implemented on top of IP multicast to facilitate reliable transfer of data for replicated databases and groupware applications that will emerge on the Internet over the next decade. This paper explores some of the basic questions and applications of reliable multicasting in the context of the development and analysis of RMP.

  14. Efficient Network Coding-Based Loss Recovery for Reliable Multicast in Wireless Networks

    NASA Astrophysics Data System (ADS)

    Chi, Kaikai; Jiang, Xiaohong; Ye, Baoliu; Horiguchi, Susumu

    Recently, network coding has been applied to the loss recovery of reliable multicast in wireless networks [19], where multiple lost packets are XOR-ed together as one packet and forwarded via single retransmission, resulting in a significant reduction of bandwidth consumption. In this paper, we first prove that maximizing the number of lost packets for XOR-ing, which is the key part of the available network coding-based reliable multicast schemes, is actually a complex NP-complete problem. To address this limitation, we then propose an efficient heuristic algorithm for finding an approximately optimal solution of this optimization problem. Furthermore, we show that the packet coding principle of maximizing the number of lost packets for XOR-ing sometimes cannot fully exploit the potential coding opportunities, and we then further propose new heuristic-based schemes with a new coding principle. Simulation results demonstrate that the heuristic-based schemes have very low computational complexity and can achieve almost the same transmission efficiency as the current coding-based high-complexity schemes. Furthermore, the heuristic-based schemes with the new coding principle not only have very low complexity, but also slightly outperform the current high-complexity ones.

  15. Minimum Interference Channel Assignment Algorithm for Multicast in a Wireless Mesh Network.

    PubMed

    Choi, Sangil; Park, Jong Hyuk

    2016-12-02

    Wireless mesh networks (WMNs) have been considered as one of the key technologies for the configuration of wireless machines since they emerged. In a WMN, wireless routers provide multi-hop wireless connectivity between hosts in the network and also allow them to access the Internet via gateway devices. Wireless routers are typically equipped with multiple radios operating on different channels to increase network throughput. Multicast is a form of communication that delivers data from a source to a set of destinations simultaneously. It is used in a number of applications, such as distributed games, distance education, and video conferencing. In this study, we address a channel assignment problem for multicast in multi-radio multi-channel WMNs. In a multi-radio multi-channel WMN, two nearby nodes will interfere with each other and cause a throughput decrease when they transmit on the same channel. Thus, an important goal for multicast channel assignment is to reduce the interference among networked devices. We have developed a minimum interference channel assignment (MICA) algorithm for multicast that accurately models the interference relationship between pairs of multicast tree nodes using the concept of the interference factor and assigns channels to tree nodes to minimize interference within the multicast tree. Simulation results show that MICA achieves higher throughput and lower end-to-end packet delay compared with an existing channel assignment algorithm named multi-channel multicast (MCM). In addition, MICA achieves much lower throughput variation among the destination nodes than MCM.

  16. Minimum Interference Channel Assignment Algorithm for Multicast in a Wireless Mesh Network

    PubMed Central

    Choi, Sangil; Park, Jong Hyuk

    2016-01-01

    Wireless mesh networks (WMNs) have been considered as one of the key technologies for the configuration of wireless machines since they emerged. In a WMN, wireless routers provide multi-hop wireless connectivity between hosts in the network and also allow them to access the Internet via gateway devices. Wireless routers are typically equipped with multiple radios operating on different channels to increase network throughput. Multicast is a form of communication that delivers data from a source to a set of destinations simultaneously. It is used in a number of applications, such as distributed games, distance education, and video conferencing. In this study, we address a channel assignment problem for multicast in multi-radio multi-channel WMNs. In a multi-radio multi-channel WMN, two nearby nodes will interfere with each other and cause a throughput decrease when they transmit on the same channel. Thus, an important goal for multicast channel assignment is to reduce the interference among networked devices. We have developed a minimum interference channel assignment (MICA) algorithm for multicast that accurately models the interference relationship between pairs of multicast tree nodes using the concept of the interference factor and assigns channels to tree nodes to minimize interference within the multicast tree. Simulation results show that MICA achieves higher throughput and lower end-to-end packet delay compared with an existing channel assignment algorithm named multi-channel multicast (MCM). In addition, MICA achieves much lower throughput variation among the destination nodes than MCM. PMID:27918438

  17. MTP: An atomic multicast transport protocol

    NASA Technical Reports Server (NTRS)

    Freier, Alan O.; Marzullo, Keith

    1990-01-01

    Multicast transport protocol (MTP); a reliable transport protocol that utilizes the multicast strategy of applicable lower layer network architectures is described. In addition to transporting data reliably and efficiently, MTP provides the client synchronization necessary for agreement on the receipt of data and the joining of the group of communicants.

  18. Proxy-assisted multicasting of video streams over mobile wireless networks

    NASA Astrophysics Data System (ADS)

    Nguyen, Maggie; Pezeshkmehr, Layla; Moh, Melody

    2005-03-01

    This work addresses the challenge of providing seamless multimedia services to mobile users by proposing a proxy-assisted multicast architecture for delivery of video streams. We propose a hybrid system of streaming proxies, interconnected by an application-layer multicast tree, where each proxy acts as a cluster head to stream out content to its stationary and mobile users. The architecture is based on our previously proposed Enhanced-NICE protocol, which uses an application-layer multicast tree to deliver layered video streams to multiple heterogeneous receivers. We targeted the study on placements of streaming proxies to enable efficient delivery of live and on-demand video, supporting both stationary and mobile users. The simulation results are evaluated and compared with two other baseline scenarios: one with a centralized proxy system serving the entire population and one with mini-proxies each to serve its local users. The simulations are implemented using the J-SIM simulator. The results show that even though proxies in the hybrid scenario experienced a slightly longer delay, they had the lowest drop rate of video content. This finding illustrates the significance of task sharing in multiple proxies. The resulted load balancing among proxies has provided a better video quality delivered to a larger audience.

  19. Remote software upload techniques in future vehicles and their performance analysis

    NASA Astrophysics Data System (ADS)

    Hossain, Irina

    Updating software in vehicle Electronic Control Units (ECUs) will become a mandatory requirement for a variety of reasons, for examples, to update/fix functionality of an existing system, add new functionality, remove software bugs and to cope up with ITS infrastructure. Software modules of advanced vehicles can be updated using Remote Software Upload (RSU) technique. The RSU employs infrastructure-based wireless communication technique where the software supplier sends the software to the targeted vehicle via a roadside Base Station (BS). However, security is critically important in RSU to avoid any disasters due to malfunctions of the vehicle or to protect the proprietary algorithms from hackers, competitors or people with malicious intent. In this thesis, a mechanism of secure software upload in advanced vehicles is presented which employs mutual authentication of the software provider and the vehicle using a pre-shared authentication key before sending the software. The software packets are sent encrypted with a secret key along with the Message Digest (MD). In order to increase the security level, it is proposed the vehicle to receive more than one copy of the software along with the MD in each copy. The vehicle will install the new software only when it receives more than one identical copies of the software. In order to validate the proposition, analytical expressions of average number of packet transmissions for successful software update is determined. Different cases are investigated depending on the vehicle's buffer size and verification methods. The analytical and simulation results show that it is sufficient to send two copies of the software to the vehicle to thwart any security attack while uploading the software. The above mentioned unicast method for RSU is suitable when software needs to be uploaded to a single vehicle. Since multicasting is the most efficient method of group communication, updating software in an ECU of a large number of vehicles could benefit from it. However, like the unicast RSU, the security requirements of multicast communication, i.e., authenticity, confidentiality and integrity of the software transmitted and access control of the group members is challenging. In this thesis, an infrastructure-based mobile multicasting for RSU in vehicle ECUs is proposed where an ECU receives the software from a remote software distribution center using the road side BSs as gateways. The Vehicular Software Distribution Network (VSDN) is divided into small regions administered by a Regional Group Manager (RGM). Two multicast Group Key Management (GKM) techniques are proposed based on the degree of trust on the BSs named Fully-trusted (FT) and Semi-trusted (ST) systems. Analytical models are developed to find the multicast session establishment latency and handover latency for these two protocols. The average latency to perform mutual authentication of the software vendor and a vehicle, and to send the multicast session key by the software provider during multicast session initialization, and the handoff latency during multicast session is calculated. Analytical and simulation results show that the link establishment latency per vehicle of our proposed schemes is in the range of few seconds and the ST system requires few ms higher time than the FT system. The handoff latency is also in the range of few seconds and in some cases ST system requires less handoff time than the FT system. Thus, it is possible to build an efficient GKM protocol without putting too much trust on the BSs.

  20. Many-to-Many Multicast Routing Schemes under a Fixed Topology

    PubMed Central

    Ding, Wei; Wang, Hongfa; Wei, Xuerui

    2013-01-01

    Many-to-many multicast routing can be extensively applied in computer or communication networks supporting various continuous multimedia applications. The paper focuses on the case where all users share a common communication channel while each user is both a sender and a receiver of messages in multicasting as well as an end user. In this case, the multicast tree appears as a terminal Steiner tree (TeST). The problem of finding a TeST with a quality-of-service (QoS) optimization is frequently NP-hard. However, we discover that it is a good idea to find a many-to-many multicast tree with QoS optimization under a fixed topology. In this paper, we are concerned with three kinds of QoS optimization objectives of multicast tree, that is, the minimum cost, minimum diameter, and maximum reliability. All of three optimization problems are distributed into two types, the centralized and decentralized version. This paper uses the dynamic programming method to devise an exact algorithm, respectively, for the centralized and decentralized versions of each optimization problem. PMID:23589706

  1. An Economic Case for End System Multicast

    NASA Astrophysics Data System (ADS)

    Analoui, Morteza; Rezvani, Mohammad Hossein

    This paper presents a non-strategic model for the end-system multicast networks based on the concept of replica exchange economy. We believe that microeconomics is a good candidate to investigate the problem of selfishness of the end-users (peers) in order to maximize the aggregate throughput. In this solution concept, the decisions that a peer might make, does not affect the actions of the other peers at all. The proposed mechanism tunes the price of the service in such a way that general equilibrium holds.

  2. Fault recovery in the reliable multicast protocol

    NASA Technical Reports Server (NTRS)

    Callahan, John R.; Montgomery, Todd L.; Whetten, Brian

    1995-01-01

    The Reliable Multicast Protocol (RMP) provides a unique, group-based model for distributed programs that need to handle reconfiguration events at the application layer. This model, called membership views, provides an abstraction in which events such as site failures, network partitions, and normal join-leave events are viewed as group reformations. RMP provides access to this model through an application programming interface (API) that notifies an application when a group is reformed as the result of a some event. RMP provides applications with reliable delivery of messages using an underlying IP Multicast (12, 5) media to other group members in a distributed environment even in the case of reformations. A distributed application can use various Quality of Service (QoS) levels provided by RMP to tolerate group reformations. This paper explores the implementation details of the mechanisms in RMP that provide distributed applications with membership view information and fault recovery capabilities.

  3. Specification and Design of a Fault Recovery Model for the Reliable Multicast Protocol

    NASA Technical Reports Server (NTRS)

    Montgomery, Todd; Callahan, John R.; Whetten, Brian

    1996-01-01

    The Reliable Multicast Protocol (RMP) provides a unique, group-based model for distributed programs that need to handle reconfiguration events at the application layer. This model, called membership views, provides an abstraction in which events such as site failures, network partitions, and normal join-leave events are viewed as group reformations. RMP provides access to this model through an application programming interface (API) that notifies an application when a group is reformed as the result of a some event. RMP provides applications with reliable delivery of messages using an underlying IP Multicast media to other group members in a distributed environment even in the case of reformations. A distributed application can use various Quality of Service (QoS) levels provided by RMP to tolerate group reformations. This paper explores the implementation details of the mechanisms in RMP that provide distributed applications with membership view information and fault recovery capabilities.

  4. On-board B-ISDN fast packet switching architectures. Phase 2: Development. Proof-of-concept architecture definition report

    NASA Technical Reports Server (NTRS)

    Shyy, Dong-Jye; Redman, Wayne

    1993-01-01

    For the next-generation packet switched communications satellite system with onboard processing and spot-beam operation, a reliable onboard fast packet switch is essential to route packets from different uplink beams to different downlink beams. The rapid emergence of point-to-point services such as video distribution, and the large demand for video conference, distributed data processing, and network management makes the multicast function essential to a fast packet switch (FPS). The satellite's inherent broadcast features gives the satellite network an advantage over the terrestrial network in providing multicast services. This report evaluates alternate multicast FPS architectures for onboard baseband switching applications and selects a candidate for subsequent breadboard development. Architecture evaluation and selection will be based on the study performed in phase 1, 'Onboard B-ISDN Fast Packet Switching Architectures', and other switch architectures which have become commercially available as large scale integration (LSI) devices.

  5. An efficient group multicast routing for multimedia communication

    NASA Astrophysics Data System (ADS)

    Wang, Yanlin; Sun, Yugen; Yan, Xinfang

    2004-04-01

    Group multicasting is a kind of communication mechanism whereby each member of a group sends messages to all the other members of the same group. Group multicast routing algorithms capable of satisfying quality of service (QoS) requirements of multimedia applications are essential for high-speed networks. We present a heuristic algorithm for group multicast routing with end to end delay constraint. Source-specific routing trees for each member are generated in our algorithm, which satisfy member"s bandwidth and end to end delay requirements. Simulations over random network were carried out to compare proposed algorithm performance with Low and Song"s. The experimental results show that our proposed algorithm performs better in terms of network cost and ability in constructing feasible multicast trees for group members. Moreover, our algorithm achieves good performance in balancing traffic, which can avoid link blocking and enhance the network behavior efficiently.

  6. Design and development of cell queuing, processing, and scheduling modules for the iPOINT input-buffered ATM testbed

    NASA Astrophysics Data System (ADS)

    Duan, Haoran

    1997-12-01

    This dissertation presents the concepts, principles, performance, and implementation of input queuing and cell-scheduling modules for the Illinois Pulsar-based Optical INTerconnect (iPOINT) input-buffered Asynchronous Transfer Mode (ATM) testbed. Input queuing (IQ) ATM switches are well suited to meet the requirements of current and future ultra-broadband ATM networks. The IQ structure imposes minimum memory bandwidth requirements for cell buffering, tolerates bursty traffic, and utilizes memory efficiently for multicast traffic. The lack of efficient cell queuing and scheduling solutions has been a major barrier to build high-performance, scalable IQ-based ATM switches. This dissertation proposes a new Three-Dimensional Queue (3DQ) and a novel Matrix Unit Cell Scheduler (MUCS) to remove this barrier. 3DQ uses a linked-list architecture based on Synchronous Random Access Memory (SRAM) to combine the individual advantages of per-virtual-circuit (per-VC) queuing, priority queuing, and N-destination queuing. It avoids Head of Line (HOL) blocking and provides per-VC Quality of Service (QoS) enforcement mechanisms. Computer simulation results verify the QoS capabilities of 3DQ. For multicast traffic, 3DQ provides efficient usage of cell buffering memory by storing multicast cells only once. Further, the multicast mechanism of 3DQ prevents a congested destination port from blocking other less- loaded ports. The 3DQ principle has been prototyped in the Illinois Input Queue (iiQueue) module. Using Field Programmable Gate Array (FPGA) devices, SRAM modules, and integrated on a Printed Circuit Board (PCB), iiQueue can process incoming traffic at 800 Mb/s. Using faster circuit technology, the same design is expected to operate at the OC-48 rate (2.5 Gb/s). MUCS resolves the output contention by evaluating the weight index of each candidate and selecting the heaviest. It achieves near-optimal scheduling and has a very short response time. The algorithm originates from a heuristic strategy that leads to 'socially optimal' solutions, yielding a maximum number of contention-free cells being scheduled. A novel mixed digital-analog circuit has been designed to implement the MUCS core functionality. The MUCS circuit maps the cell scheduling computation to the capacitor charging and discharging procedures that are conducted fully in parallel. The design has a uniform circuit structure, low interconnect counts, and low chip I/O counts. Using 2 μm CMOS technology, the design operates on a 100 MHz clock and finds a near-optimal solution within a linear processing time. The circuit has been verified at the transistor level by HSPICE simulation. During this research, a five-port IQ-based optoelectronic iPOINT ATM switch has been developed and demonstrated. It has been fully functional with an aggregate throughput of 800 Mb/s. The second-generation IQ-based switch is currently under development. Equipped with iiQueue modules and MUCS module, the new switch system will deliver a multi-gigabit aggregate throughput, eliminate HOL blocking, provide per-VC QoS, and achieve near-100% link bandwidth utilization. Complete documentation of input modules and trunk module for the existing testbed, and complete documentation of 3DQ, iiQueue, and MUCS for the second-generation testbed are given in this dissertation.

  7. A high performance totally ordered multicast protocol

    NASA Technical Reports Server (NTRS)

    Montgomery, Todd; Whetten, Brian; Kaplan, Simon

    1995-01-01

    This paper presents the Reliable Multicast Protocol (RMP). RMP provides a totally ordered, reliable, atomic multicast service on top of an unreliable multicast datagram service such as IP Multicasting. RMP is fully and symmetrically distributed so that no site bears un undue portion of the communication load. RMP provides a wide range of guarantees, from unreliable delivery to totally ordered delivery, to K-resilient, majority resilient, and totally resilient atomic delivery. These QoS guarantees are selectable on a per packet basis. RMP provides many communication options, including virtual synchrony, a publisher/subscriber model of message delivery, an implicit naming service, mutually exclusive handlers for messages, and mutually exclusive locks. It has commonly been held that a large performance penalty must be paid in order to implement total ordering -- RMP discounts this. On SparcStation 10's on a 1250 KB/sec Ethernet, RMP provides totally ordered packet delivery to one destination at 842 KB/sec throughput and with 3.1 ms packet latency. The performance stays roughly constant independent of the number of destinations. For two or more destinations on a LAN, RMP provides higher throughput than any protocol that does not use multicast or broadcast.

  8. Hybrid monitoring scheme for end-to-end performance enhancement of multicast-based real-time media

    NASA Astrophysics Data System (ADS)

    Park, Ju-Won; Kim, JongWon

    2004-10-01

    As real-time media applications based on IP multicast networks spread widely, end-to-end QoS (quality of service) provisioning for these applications have become very important. To guarantee the end-to-end QoS of multi-party media applications, it is essential to monitor the time-varying status of both network metrics (i.e., delay, jitter and loss) and system metrics (i.e., CPU and memory utilization). In this paper, targeting the multicast-enabled AG (Access Grid) a next-generation group collaboration tool based on multi-party media services, the applicability of hybrid monitoring scheme that combines active and passive monitoring is investigated. The active monitoring measures network-layer metrics (i.e., network condition) with probe packets while the passive monitoring checks both application-layer metrics (i.e., user traffic condition by analyzing RTCP packets) and system metrics. By comparing these hybrid results, we attempt to pinpoint the causes of performance degradation and explore corresponding reactions to improve the end-to-end performance. The experimental results show that the proposed hybrid monitoring can provide useful information to coordinate the performance improvement of multi-party real-time media applications.

  9. Experimental Evaluation of Unicast and Multicast CoAP Group Communication

    PubMed Central

    Ishaq, Isam; Hoebeke, Jeroen; Moerman, Ingrid; Demeester, Piet

    2016-01-01

    The Internet of Things (IoT) is expanding rapidly to new domains in which embedded devices play a key role and gradually outnumber traditionally-connected devices. These devices are often constrained in their resources and are thus unable to run standard Internet protocols. The Constrained Application Protocol (CoAP) is a new alternative standard protocol that implements the same principals as the Hypertext Transfer Protocol (HTTP), but is tailored towards constrained devices. In many IoT application domains, devices need to be addressed in groups in addition to being addressable individually. Two main approaches are currently being proposed in the IoT community for CoAP-based group communication. The main difference between the two approaches lies in the underlying communication type: multicast versus unicast. In this article, we experimentally evaluate those two approaches using two wireless sensor testbeds and under different test conditions. We highlight the pros and cons of each of them and propose combining these approaches in a hybrid solution to better suit certain use case requirements. Additionally, we provide a solution for multicast-based group membership management using CoAP. PMID:27455262

  10. Multicast Routing and Wavelength Assignment with Shared Protection in Multi-Fiber WDM Mesh Networks: Optimal and Heuristic Solutions

    NASA Astrophysics Data System (ADS)

    Woradit, Kampol; Guyot, Matthieu; Vanichchanunt, Pisit; Saengudomlert, Poompat; Wuttisittikulkij, Lunchakorn

    While the problem of multicast routing and wavelength assignment (MC-RWA) in optical wavelength division multiplexing (WDM) networks has been investigated, relatively few researchers have considered network survivability for multicasting. This paper provides an optimization framework to solve the MC-RWA problem in a multi-fiber WDM network that can recover from a single-link failure with shared protection. Using the light-tree (LT) concept to support multicast sessions, we consider two protection strategies that try to reduce service disruptions after a link failure. The first strategy, called light-tree reconfiguration (LTR) protection, computes a new multicast LT for each session affected by the failure. The second strategy, called optical branch reconfiguration (OBR) protection, tries to restore a logical connection between two adjacent multicast members disconnected by the failure. To solve the MC-RWA problem optimally, we propose an integer linear programming (ILP) formulation that minimizes the total number of fibers required for both working and backup traffic. The ILP formulation takes into account joint routing of working and backup traffic, the wavelength continuity constraint, and the limited splitting degree of multicast-capable optical cross-connects (MC-OXCs). After showing some numerical results for optimal solutions, we propose heuristic algorithms that reduce the computational complexity and make the problem solvable for large networks. Numerical results suggest that the proposed heuristic yields efficient solutions compared to optimal solutions obtained from exact optimization.

  11. Robust Group Sparse Beamforming for Multicast Green Cloud-RAN With Imperfect CSI

    NASA Astrophysics Data System (ADS)

    Shi, Yuanming; Zhang, Jun; Letaief, Khaled B.

    2015-09-01

    In this paper, we investigate the network power minimization problem for the multicast cloud radio access network (Cloud-RAN) with imperfect channel state information (CSI). The key observation is that network power minimization can be achieved by adaptively selecting active remote radio heads (RRHs) via controlling the group-sparsity structure of the beamforming vector. However, this yields a non-convex combinatorial optimization problem, for which we propose a three-stage robust group sparse beamforming algorithm. In the first stage, a quadratic variational formulation of the weighted mixed l1/l2-norm is proposed to induce the group-sparsity structure in the aggregated beamforming vector, which indicates those RRHs that can be switched off. A perturbed alternating optimization algorithm is then proposed to solve the resultant non-convex group-sparsity inducing optimization problem by exploiting its convex substructures. In the second stage, we propose a PhaseLift technique based algorithm to solve the feasibility problem with a given active RRH set, which helps determine the active RRHs. Finally, the semidefinite relaxation (SDR) technique is adopted to determine the robust multicast beamformers. Simulation results will demonstrate the convergence of the perturbed alternating optimization algorithm, as well as, the effectiveness of the proposed algorithm to minimize the network power consumption for multicast Cloud-RAN.

  12. Hybrid digital-analog video transmission in wireless multicast and multiple-input multiple-output system

    NASA Astrophysics Data System (ADS)

    Liu, Yu; Lin, Xiaocheng; Fan, Nianfei; Zhang, Lin

    2016-01-01

    Wireless video multicast has become one of the key technologies in wireless applications. But the main challenge of conventional wireless video multicast, i.e., the cliff effect, remains unsolved. To overcome the cliff effect, a hybrid digital-analog (HDA) video transmission framework based on SoftCast, which transmits the digital bitstream with the quantization residuals, is proposed. With an effective power allocation algorithm and appropriate parameter settings, the residual gains can be maximized; meanwhile, the digital bitstream can assure transmission of a basic video to the multicast receiver group. In the multiple-input multiple-output (MIMO) system, since nonuniform noise interference on different antennas can be regarded as the cliff effect problem, ParCast, which is a variation of SoftCast, is also applied to video transmission to solve it. The HDA scheme with corresponding power allocation algorithms is also applied to improve video performance. Simulations show that the proposed HDA scheme can overcome the cliff effect completely with the transmission of residuals. What is more, it outperforms the compared WSVC scheme by more than 2 dB when transmitting under the same bandwidth, and it can further improve performance by nearly 8 dB in MIMO when compared with the ParCast scheme.

  13. Programming with process groups: Group and multicast semantics

    NASA Technical Reports Server (NTRS)

    Birman, Kenneth P.; Cooper, Robert; Gleeson, Barry

    1991-01-01

    Process groups are a natural tool for distributed programming and are increasingly important in distributed computing environments. Discussed here is a new architecture that arose from an effort to simplify Isis process group semantics. The findings include a refined notion of how the clients of a group should be treated, what the properties of a multicast primitive should be when systems contain large numbers of overlapping groups, and a new construct called the causality domain. A system based on this architecture is now being implemented in collaboration with the Chorus and Mach projects.

  14. Performance investigation of optical multicast overlay system using orthogonal modulation format

    NASA Astrophysics Data System (ADS)

    Singh, Simranjit; Singh, Sukhbir; Kaur, Ramandeep; Kaler, R. S.

    2015-03-01

    We proposed a bandwidth efficient wavelength division multiplexed-passive optical network (WDM-PON) to simultaneously transmit 60 Gb/s unicast and 10 Gb/s multicast services with 10 Gb/s upstream. The differential phase shift keying (DPSK) multicast signal is superimposed onto multiplexed non-return to zero/polarization shift keying (NRZ/PolSK) orthogonal modulated data signals. Upstream amplitude shift keying (ASK) signals formed without use of any additional light source and superimposed onto received unicast NRZ/PolSK signal before being transmitted back to optical line terminal (OLT). We also investigated the proposed WDM-PON system for variable optical input power, transmission distance of single mode fiber in multicast enable and disable mode. The measured Quality factor for all unicast and multicast signal is in acceptable range (>6). The original contribution of this paper is to propose a bandwidth efficient WDM-PON system that could be projected even in high speed scenario at reduced channel spacing and expected to be more technical viable due to use of optical orthogonal modulation formats.

  15. High-speed free-space based reconfigurable card-to-card optical interconnects with broadcast capability.

    PubMed

    Wang, Ke; Nirmalathas, Ampalavanapillai; Lim, Christina; Skafidas, Efstratios; Alameh, Kamal

    2013-07-01

    In this paper, we propose and experimentally demonstrate a free-space based high-speed reconfigurable card-to-card optical interconnect architecture with broadcast capability, which is required for control functionalities and efficient parallel computing applications. Experimental results show that 10 Gb/s data can be broadcast to all receiving channels for up to 30 cm with a worst-case receiver sensitivity better than -12.20 dBm. In addition, arbitrary multicasting with the same architecture is also investigated. 10 Gb/s reconfigurable point-to-point link and multicast channels are simultaneously demonstrated with a measured receiver sensitivity power penalty of ~1.3 dB due to crosstalk.

  16. Inertial Motion Tracking for Inserting Humans into a Networked Synthetic Environment

    DTIC Science & Technology

    2007-08-31

    tracking methods. One method requires markers on the tracked buman body, and other method does not use nmkers. OPTOTRAK from Northem Digital Inc. is a...of using multicasting protocols. Unfortunately, most routers on the Internet are not configured for multicasting. A technique called tunneling is...used to overcome this problem. Tunneling is a software solution that m s on the end point routerslcomputers and allows multicast packets to traverse

  17. Multicast for savings in cache-based video distribution

    NASA Astrophysics Data System (ADS)

    Griwodz, Carsten; Zink, Michael; Liepert, Michael; On, Giwon; Steinmetz, Ralf

    1999-12-01

    Internet video-on-demand (VoD) today streams videos directly from server to clients, because re-distribution is not established yet. Intranet solutions exist but are typically managed centrally. Caching may overcome these management needs, however existing web caching strategies are not applicable because they work in different conditions. We propose movie distribution by means of caching, and study the feasibility from the service providers' point of view. We introduce the combination of our reliable multicast protocol LCRTP for caching hierarchies combined with our enhancement to the patching technique for bandwidth friendly True VoD, not depending on network resource guarantees.

  18. The reliable multicast protocol application programming interface

    NASA Technical Reports Server (NTRS)

    Montgomery , Todd; Whetten, Brian

    1995-01-01

    The Application Programming Interface for the Berkeley/WVU implementation of the Reliable Multicast Protocol is described. This transport layer protocol is implemented as a user library that applications and software buses link against.

  19. The multidriver: A reliable multicast service using the Xpress Transfer Protocol

    NASA Technical Reports Server (NTRS)

    Dempsey, Bert J.; Fenton, John C.; Weaver, Alfred C.

    1990-01-01

    A reliable multicast facility extends traditional point-to-point virtual circuit reliability to one-to-many communication. Such services can provide more efficient use of network resources, a powerful distributed name binding capability, and reduced latency in multidestination message delivery. These benefits will be especially valuable in real-time environments where reliable multicast can enable new applications and increase the availability and the reliability of data and services. We present a unique multicast service that exploits features in the next-generation, real-time transfer layer protocol, the Xpress Transfer Protocol (XTP). In its reliable mode, the service offers error, flow, and rate-controlled multidestination delivery of arbitrary-sized messages, with provision for the coordination of reliable reverse channels. Performance measurements on a single-segment Proteon ProNET-4 4 Mbps 802.5 token ring with heterogeneous nodes are discussed.

  20. Flexible and re-configurable optical three-input XOR logic gate of phase-modulated signals with multicast functionality for potential application in optical physical-layer network coding.

    PubMed

    Lu, Guo-Wei; Qin, Jun; Wang, Hongxiang; Ji, XuYuefeng; Sharif, Gazi Mohammad; Yamaguchi, Shigeru

    2016-02-08

    Optical logic gate, especially exclusive-or (XOR) gate, plays important role in accomplishing photonic computing and various network functionalities in future optical networks. On the other hand, optical multicast is another indispensable functionality to efficiently deliver information in optical networks. In this paper, for the first time, we propose and experimentally demonstrate a flexible optical three-input XOR gate scheme for multiple input phase-modulated signals with a 1-to-2 multicast functionality for each XOR operation using four-wave mixing (FWM) effect in single piece of highly-nonlinear fiber (HNLF). Through FWM in HNLF, all of the possible XOR operations among input signals could be simultaneously realized by sharing a single piece of HNLF. By selecting the obtained XOR components using a followed wavelength selective component, the number of XOR gates and the participant light in XOR operations could be flexibly configured. The re-configurability of the proposed XOR gate and the function integration of the optical logic gate and multicast in single device offer the flexibility in network design and improve the network efficiency. We experimentally demonstrate flexible 3-input XOR gate for four 10-Gbaud binary phase-shift keying signals with a multicast scale of 2. Error-free operations for the obtained XOR results are achieved. Potential application of the integrated XOR and multicast function in network coding is also discussed.

  1. Demonstration of flexible multicasting and aggregation functionality for TWDM-PON

    NASA Astrophysics Data System (ADS)

    Chen, Yuanxiang; Li, Juhao; Zhu, Paikun; Zhu, Jinglong; Tian, Yu; Wu, Zhongying; Peng, Huangfa; Xu, Yongchi; Chen, Jingbiao; He, Yongqi; Chen, Zhangyuan

    2017-06-01

    The time- and wavelength-division multiplexed passive optical network (TWDM-PON) has been recognized as an attractive solution to provide broadband access for the next-generation networks. In this paper, we propose flexible service multicasting and aggregation functionality for TWDM-PON utilizing multiple-pump four-wave-mixing (FWM) and cyclic arrayed waveguide grating (AWG). With the proposed scheme, multiple TWDM-PON links share a single optical line terminal (OLT), which can greatly reduce the network deployment expense and achieve efficient network resource utilization by load balancing among different optical distribution networks (ODNs). The proposed scheme is compatible with existing TDM-PON infrastructure with fixed-wavelength OLT transmitter, thus smooth service upgrade can be achieved. Utilizing the proposed scheme, we demonstrate a proof-of-concept experiment with 10-Gb/s OOK and 10-Gb/s QPSK orthogonal frequency division multiplexing (OFDM) signal multicasting and aggregating to seven PON links. Compared with back-to-back (BTB) channel, the newly generated multicasting OOK signal and OFDM signal have power penalty of 1.6 dB and 2 dB at the BER of 10-3, respectively. For the aggregation of multiple channels, no obvious power penalty is observed. What is more, to verify the flexibility of the proposed scheme, we reconfigure the wavelength selective switch (WSS) and adjust the number of pumps to realize flexible multicasting functionality. One to three, one to seven, one to thirteen and one to twenty-one multicasting are achieved without modifying OLT structure.

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

    PubMed Central

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

    2017-01-01

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

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

    PubMed

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

    2016-01-01

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

  4. Digital multi-channel stabilization of four-mode phase-sensitive parametric multicasting.

    PubMed

    Liu, Lan; Tong, Zhi; Wiberg, Andreas O J; Kuo, Bill P P; Myslivets, Evgeny; Alic, Nikola; Radic, Stojan

    2014-07-28

    Stable four-mode phase-sensitive (4MPS) process was investigated as a means to enhance two-pump driven parametric multicasting conversion efficiency (CE) and signal to noise ratio (SNR). Instability of multi-beam, phase sensitive (PS) device that inherently behaves as an interferometer, with output subject to ambient induced fluctuations, was addressed theoretically and experimentally. A new stabilization technique that controls phases of three input waves of the 4MPS multicaster and maximizes CE was developed and described. Stabilization relies on digital phase-locked loop (DPLL) specifically was developed to control pump phases to guarantee stable 4MPS operation that is independent of environmental fluctuations. The technique also controls a single (signal) input phase to optimize the PS-induced improvement of the CE and SNR. The new, continuous-operation DPLL has allowed for fully stabilized PS parametric broadband multicasting, demonstrating CE improvement over 20 signal copies in excess of 10 dB.

  5. Multicast Routing of Hierarchical Data

    NASA Technical Reports Server (NTRS)

    Shacham, Nachum

    1992-01-01

    The issue of multicast of broadband, real-time data in a heterogeneous environment, in which the data recipients differ in their reception abilities, is considered. Traditional multicast schemes, which are designed to deliver all the source data to all recipients, offer limited performance in such an environment, since they must either force the source to overcompress its signal or restrict the destination population to those who can receive the full signal. We present an approach for resolving this issue by combining hierarchical source coding techniques, which allow recipients to trade off reception bandwidth for signal quality, and sophisticated routing algorithms that deliver to each destination the maximum possible signal quality. The field of hierarchical coding is briefly surveyed and new multicast routing algorithms are presented. The algorithms are compared in terms of network utilization efficiency, lengths of paths, and the required mechanisms for forwarding packets on the resulting paths.

  6. Multisites Coordination in Shared Multicast Trees

    DTIC Science & Technology

    1999-01-01

    conferencing, distributed interactive simulations, and collaborative systems. We de- scribe a novel protocol to coordinate multipoint groupwork in the IP...multicast framework. The pro- tocol supports Internet-wide coordination for large and highly-interactive groupwork , relying on trans- mission of

  7. Optimization of multicast optical networks with genetic algorithm

    NASA Astrophysics Data System (ADS)

    Lv, Bo; Mao, Xiangqiao; Zhang, Feng; Qin, Xi; Lu, Dan; Chen, Ming; Chen, Yong; Cao, Jihong; Jian, Shuisheng

    2007-11-01

    In this letter, aiming to obtain the best multicast performance of optical network in which the video conference information is carried by specified wavelength, we extend the solutions of matrix games with the network coding theory and devise a new method to solve the complex problems of multicast network switching. In addition, an experimental optical network has been testified with best switching strategies by employing the novel numerical solution designed with an effective way of genetic algorithm. The result shows that optimal solutions with genetic algorithm are accordance with the ones with the traditional fictitious play method.

  8. Fast casual multicast

    NASA Technical Reports Server (NTRS)

    Birman, Kenneth; Schiper, Andre; Stephenson, Pat

    1990-01-01

    A new protocol is presented that efficiently implements a reliable, causally ordered multicast primitive and is easily extended into a totally ordered one. Intended for use in the ISIS toolkit, it offers a way to bypass the most costly aspects of ISIS while benefiting from virtual synchrony. The facility scales with bounded overhead. Measured speedups of more than an order of magnitude were obtained when the protocol was implemented within ISIS. One conclusion is that systems such as ISIS can achieve performance competitive with the best existing multicast facilities--a finding contradicting the widespread concern that fault-tolerance may be unacceptably costly.

  9. 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

  10. 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.

  11. Towards Microeconomic Resource Sharing in End System Multicast Networks Based on Walrasian General Equilibrium

    NASA Astrophysics Data System (ADS)

    Rezvani, Mohammad Hossein; Analoui, Morteza

    2010-11-01

    We have designed a competitive economical mechanism for application level multicast in which a number of independent services are provided to the end-users by a number of origin servers. Each offered service can be thought of as a commodity and the origin servers and the users who relay the service to their downstream nodes can thus be thought of as producers of the economy. Also, the end-users can be viewed as consumers of the economy. The proposed mechanism regulates the price of each service in such a way that general equilibrium holds. So, all allocations will be Pareto optimal in the sense that the social welfare of the users is maximized.

  12. XML Tactical Chat (XTC): The Way Ahead for Navy Chat

    DTIC Science & Technology

    2007-09-01

    multicast transmissions via sophisticated pruning algorithms, while allowing multicast packets to “ tunnel ” through IP routers. [Macedonia, Brutzman 1994...conference was Jabber Inc. who added some great insight into the power of Jabber. • Great features including blackberry handheld connectivity and

  13. An FEC Adaptive Multicast MAC Protocol for Providing Reliability in WLANs

    NASA Astrophysics Data System (ADS)

    Basalamah, Anas; Sato, Takuro

    For wireless multicast applications like multimedia conferencing, voice over IP and video/audio streaming, a reliable transmission of packets within short delivery delay is needed. Moreover, reliability is crucial to the performance of error intolerant applications like file transfer, distributed computing, chat and whiteboard sharing. Forward Error Correction (FEC) is frequently used in wireless multicast to enhance Packet Error Rate (PER) performance, but cannot assure full reliability unless coupled with Automatic Repeat Request forming what is knows as Hybrid-ARQ. While reliable FEC can be deployed at different levels of the protocol stack, it cannot be deployed on the MAC layer of the unreliable IEEE802.11 WLAN due to its inability to exchange ACKs with multiple recipients. In this paper, we propose a Multicast MAC protocol that enhances WLAN reliability by using Adaptive FEC and study it's performance through mathematical analysis and simulation. Our results show that our protocol can deliver high reliability and throughput performance.

  14. Reliable WDM multicast in optical burst-switched networks

    NASA Astrophysics Data System (ADS)

    Jeong, Myoungki; Qiao, Chunming; Xiong, Yijun

    2000-09-01

    IN this paper,l we present a reliable WDM (Wavelength-Division Multiplexing) multicast protocol in optical burst-switched (OBS) networks. Since the burst dropping (loss) probability may be potentially high in a heavily loaded OBS backbone network, reliable multicast protocols that have developed for IP networks at the transport (or application) layer may incur heavy overheads such as a large number of duplicate retransmissions. In addition, it may take a longer time for an end host to detect and then recover from burst dropping (loss) occurred at the WDM layer. For efficiency reasons, we propose burst loss recovery within the OBS backbone (i.e., at the WDM link layer). The proposed protocol requires two additional functions to be performed by the WDM switch controller: subcasting and maintaining burst states, when the WDM switch has more than one downstream on the WDM multicast tree. We show that these additional functions are simple to implement and the overhead associated with them is manageable.

  15. Analysis on Multicast Routing Protocols for Mobile Ad Hoc Networks

    NASA Astrophysics Data System (ADS)

    Xiang, Ma

    As the Mobile Ad Hoc Networks technologies face a series of challenges like dynamic changes of topological structure, existence of unidirectional channel, limited wireless transmission bandwidth, the capability limitations of mobile termination and etc, therefore, the research to mobile Ad Hoc network routings inevitablely undertake a more important task than those to other networks. Multicast is a mode of communication transmission oriented to group computing, which sends the data to a group of host computers by using single source address. In a typical mobile Ad Hoc Network environment, multicast has a significant meaning. On the one hand, the users of mobile Ad Hoc Network usually need to form collaborative working groups; on the other hand, this is also an important means of fully using the broadcast performances of wireless communication and effectively using the limited wireless channel resources. This paper summarizes and comparatively analyzes the routing mechanisms of various existing multicast routing protocols according to the characteristics of mobile Ad Hoc network.

  16. WDM/TDM PON experiments using the AWG free spectral range periodicity to transmit unicast and multicast data

    NASA Astrophysics Data System (ADS)

    Bock, Carlos; Prat, Josep

    2005-04-01

    A hybrid WDM/TDM PON architecture implemented by means of two cascaded Arrayed Waveguide Gratings (AWG) is presented. Using the Free Spectral Range (FSR) periodicity of AWGs we transmit unicast and multicast traffic on different wavelengths to each Optical Network Unit (ONU). The OLT is equipped with two laser stacks, a tunable one for unicast transmission and a fixed one for multicast transmission. We propose the ONU to be reflective in order to avoid any light source at the Costumer Premises Equipment (CPE). Optical transmission tests demonstrate correct transmission at 2.5 Gbps up to 30 km.

  17. A heuristic for efficient data distribution management in distributed simulation

    NASA Astrophysics Data System (ADS)

    Gupta, Pankaj; Guha, Ratan K.

    2005-05-01

    In this paper, we propose an algorithm for reducing the complexity of region matching and efficient multicasting in data distribution management component of High Level Architecture (HLA) Run Time Infrastructure (RTI). The current data distribution management (DDM) techniques rely on computing the intersection between the subscription and update regions. When a subscription region and an update region of different federates overlap, RTI establishes communication between the publisher and the subscriber. It subsequently routes the updates from the publisher to the subscriber. The proposed algorithm computes the update/subscription regions matching for dynamic allocation of multicast group. It provides new multicast routines that exploit the connectivity of federation by communicating updates regarding interactions and routes information only to those federates that require them. The region-matching problem in DDM reduces to clique-covering problem using the connections graph abstraction where the federations represent the vertices and the update/subscribe relations represent the edges. We develop an abstract model based on connection graph for data distribution management. Using this abstract model, we propose a heuristic for solving the region-matching problem of DDM. We also provide complexity analysis of the proposed heuristics.

  18. Fingerprint multicast in secure video streaming.

    PubMed

    Zhao, H Vicky; Liu, K J Ray

    2006-01-01

    Digital fingerprinting is an emerging technology to protect multimedia content from illegal redistribution, where each distributed copy is labeled with unique identification information. In video streaming, huge amount of data have to be transmitted to a large number of users under stringent latency constraints, so the bandwidth-efficient distribution of uniquely fingerprinted copies is crucial. This paper investigates the secure multicast of anticollusion fingerprinted video in streaming applications and analyzes their performance. We first propose a general fingerprint multicast scheme that can be used with most spread spectrum embedding-based multimedia fingerprinting systems. To further improve the bandwidth efficiency, we explore the special structure of the fingerprint design and propose a joint fingerprint design and distribution scheme. From our simulations, the two proposed schemes can reduce the bandwidth requirement by 48% to 87%, depending on the number of users, the characteristics of video sequences, and the network and computation constraints. We also show that under the constraint that all colluders have the same probability of detection, the embedded fingerprints in the two schemes have approximately the same collusion resistance. Finally, we propose a fingerprint drift compensation scheme to improve the quality of the reconstructed sequences at the decoder's side without introducing extra communication overhead.

  19. Verification and validation of a reliable multicast protocol

    NASA Technical Reports Server (NTRS)

    Callahan, John R.; Montgomery, Todd L.

    1995-01-01

    This paper describes the methods used to specify and implement a complex communications protocol that provides reliable delivery of data in multicast-capable, packet-switching telecommunication networks. The protocol, called the Reliable Multicasting Protocol (RMP), was developed incrementally by two complementary teams using a combination of formal and informal techniques in an attempt to ensure the correctness of the protocol implementation. The first team, called the Design team, initially specified protocol requirements using a variant of SCR requirements tables and implemented a prototype solution. The second team, called the V&V team, developed a state model based on the requirements tables and derived test cases from these tables to exercise the implementation. In a series of iterative steps, the Design team added new functionality to the implementation while the V&V team kept the state model in fidelity with the implementation through testing. Test cases derived from state transition paths in the formal model formed the dialogue between teams during development and served as the vehicles for keeping the model and implementation in fidelity with each other. This paper describes our experiences in developing our process model, details of our approach, and some example problems found during the development of RMP.

  20. Performance Evaluation of Reliable Multicast Protocol for Checkout and Launch Control Systems

    NASA Technical Reports Server (NTRS)

    Shu, Wei Wennie; Porter, John

    2000-01-01

    The overall objective of this project is to study reliability and performance of Real Time Critical Network (RTCN) for checkout and launch control systems (CLCS). The major tasks include reliability and performance evaluation of Reliable Multicast (RM) package and fault tolerance analysis and design of dual redundant network architecture.

  1. Design, Implementation, and Verification of the Reliable Multicast Protocol. Thesis

    NASA Technical Reports Server (NTRS)

    Montgomery, Todd L.

    1995-01-01

    This document describes the Reliable Multicast Protocol (RMP) design, first implementation, and formal verification. RMP provides a totally ordered, reliable, atomic multicast service on top of an unreliable multicast datagram service. RMP is fully and symmetrically distributed so that no site bears an undue portion of the communications load. RMP provides a wide range of guarantees, from unreliable delivery to totally ordered delivery, to K-resilient, majority resilient, and totally resilient atomic delivery. These guarantees are selectable on a per message basis. RMP provides many communication options, including virtual synchrony, a publisher/subscriber model of message delivery, a client/server model of delivery, mutually exclusive handlers for messages, and mutually exclusive locks. It has been commonly believed that total ordering of messages can only be achieved at great performance expense. RMP discounts this. The first implementation of RMP has been shown to provide high throughput performance on Local Area Networks (LAN). For two or more destinations a single LAN, RMP provides higher throughput than any other protocol that does not use multicast or broadcast technology. The design, implementation, and verification activities of RMP have occurred concurrently. This has allowed the verification to maintain a high fidelity between design model, implementation model, and the verification model. The restrictions of implementation have influenced the design earlier than in normal sequential approaches. The protocol as a whole has matured smoother by the inclusion of several different perspectives into the product development.

  2. Context-based user grouping for multi-casting in heterogeneous radio networks

    NASA Astrophysics Data System (ADS)

    Mannweiler, C.; Klein, A.; Schneider, J.; Schotten, H. D.

    2011-08-01

    Along with the rise of sophisticated smartphones and smart spaces, the availability of both static and dynamic context information has steadily been increasing in recent years. Due to the popularity of social networks, these data are complemented by profile information about individual users. Making use of this information by classifying users in wireless networks enables targeted content and advertisement delivery as well as optimizing network resources, in particular bandwidth utilization, by facilitating group-based multi-casting. In this paper, we present the design and implementation of a web service for advanced user classification based on user, network, and environmental context information. The service employs simple and advanced clustering algorithms for forming classes of users. Available service functionalities include group formation, context-aware adaptation, and deletion as well as the exposure of group characteristics. Moreover, the results of a performance evaluation, where the service has been integrated in a simulator modeling user behavior in heterogeneous wireless systems, are presented.

  3. Combined Wavelet Video Coding and Error Control for Internet Streaming and Multicast

    NASA Astrophysics Data System (ADS)

    Chu, Tianli; Xiong, Zixiang

    2003-12-01

    This paper proposes an integrated approach to Internet video streaming and multicast (e.g., receiver-driven layered multicast (RLM) by McCanne) based on combined wavelet video coding and error control. We design a packetized wavelet video (PWV) coder to facilitate its integration with error control. The PWV coder produces packetized layered bitstreams that are independent among layers while being embedded within each layer. Thus, a lost packet only renders the following packets in the same layer useless. Based on the PWV coder, we search for a multilayered error-control strategy that optimally trades off source and channel coding for each layer under a given transmission rate to mitigate the effects of packet loss. While both the PWV coder and the error-control strategy are new—the former incorporates embedded wavelet video coding and packetization and the latter extends the single-layered approach for RLM by Chou et al.—the main distinction of this paper lies in the seamless integration of the two parts. Theoretical analysis shows a gain of up to 1 dB on a channel with 20% packet loss using our combined approach over separate designs of the source coder and the error-control mechanism. This is also substantiated by our simulations with a gain of up to 0.6 dB. In addition, our simulations show a gain of up to 2.2 dB over previous results reported by Chou et al.

  4. Exact and heuristic algorithms for Space Information Flow.

    PubMed

    Uwitonze, Alfred; Huang, Jiaqing; Ye, Yuanqing; Cheng, Wenqing; Li, Zongpeng

    2018-01-01

    Space Information Flow (SIF) is a new promising research area that studies network coding in geometric space, such as Euclidean space. The design of algorithms that compute the optimal SIF solutions remains one of the key open problems in SIF. This work proposes the first exact SIF algorithm and a heuristic SIF algorithm that compute min-cost multicast network coding for N (N ≥ 3) given terminal nodes in 2-D Euclidean space. Furthermore, we find that the Butterfly network in Euclidean space is the second example besides the Pentagram network where SIF is strictly better than Euclidean Steiner minimal tree. The exact algorithm design is based on two key techniques: Delaunay triangulation and linear programming. Delaunay triangulation technique helps to find practically good candidate relay nodes, after which a min-cost multicast linear programming model is solved over the terminal nodes and the candidate relay nodes, to compute the optimal multicast network topology, including the optimal relay nodes selected by linear programming from all the candidate relay nodes and the flow rates on the connection links. The heuristic algorithm design is also based on Delaunay triangulation and linear programming techniques. The exact algorithm can achieve the optimal SIF solution with an exponential computational complexity, while the heuristic algorithm can achieve the sub-optimal SIF solution with a polynomial computational complexity. We prove the correctness of the exact SIF algorithm. The simulation results show the effectiveness of the heuristic SIF algorithm.

  5. Data collection framework for energy efficient privacy preservation in wireless sensor networks having many-to-many structures.

    PubMed

    Bahşi, Hayretdin; Levi, Albert

    2010-01-01

    Wireless sensor networks (WSNs) generally have a many-to-one structure so that event information flows from sensors to a unique sink. In recent WSN applications, many-to-many structures evolved due to the need for conveying collected event information to multiple sinks. Privacy preserved data collection models in the literature do not solve the problems of WSN applications in which network has multiple un-trusted sinks with different level of privacy requirements. This study proposes a data collection framework bases on k-anonymity for preventing record disclosure of collected event information in WSNs. Proposed method takes the anonymity requirements of multiple sinks into consideration by providing different levels of privacy for each destination sink. Attributes, which may identify an event owner, are generalized or encrypted in order to meet the different anonymity requirements of sinks at the same anonymized output. If the same output is formed, it can be multicasted to all sinks. The other trivial solution is to produce different anonymized outputs for each sink and send them to related sinks. Multicasting is an energy efficient data sending alternative for some sensor nodes. Since minimization of energy consumption is an important design criteria for WSNs, multicasting the same event information to multiple sinks reduces the energy consumption of overall network.

  6. Using Interactive Broadband Multicasting in a Museum Lifelong Learning Program.

    ERIC Educational Resources Information Center

    Steinbach, Leonard

    The Cleveland Museum of Art has embarked on an innovative approach for delivering high quality video-on-demand and live interactive cultural programming, along with Web-based complementary material, to seniors in assisted living residence facilities, community-based centers, and disabled persons in their homes. The project is made possible in part…

  7. Advanced Map For Real-Time Process Control

    NASA Astrophysics Data System (ADS)

    Shiobara, Yasuhisa; Matsudaira, Takayuki; Sashida, Yoshio; Chikuma, Makoto

    1987-10-01

    MAP, a communications protocol for factory automation proposed by General Motors [1], has been accepted by users throughout the world and is rapidly becoming a user standard. In fact, it is now a LAN standard for factory automation. MAP is intended to interconnect different devices, such as computers and programmable devices, made by different manufacturers, enabling them to exchange information. It is based on the OSI intercomputer com-munications protocol standard under development by the ISO. With progress and standardization, MAP is being investigated for application to process control fields other than factory automation [2]. The transmission response time of the network system and centralized management of data exchanged with various devices for distributed control are import-ant in the case of a real-time process control with programmable controllers, computers, and instruments connected to a LAN system. MAP/EPA and MINI MAP aim at reduced overhead in protocol processing and enhanced transmission response. If applied to real-time process control, a protocol based on point-to-point and request-response transactions limits throughput and transmission response. This paper describes an advanced MAP LAN system applied to real-time process control by adding a new data transmission control that performs multicasting communication voluntarily and periodically in the priority order of data to be exchanged.

  8. Reliable multicast protocol specifications protocol operations

    NASA Technical Reports Server (NTRS)

    Callahan, John R.; Montgomery, Todd; Whetten, Brian

    1995-01-01

    This appendix contains the complete state tables for Reliable Multicast Protocol (RMP) Normal Operation, Multi-RPC Extensions, Membership Change Extensions, and Reformation Extensions. First the event types are presented. Afterwards, each RMP operation state, normal and extended, is presented individually and its events shown. Events in the RMP specification are one of several things: (1) arriving packets, (2) expired alarms, (3) user events, (4) exceptional conditions.

  9. Tera-node Network Technology (Task 3) Scalable Personal Telecommunications

    DTIC Science & Technology

    2000-03-14

    Simulation results of this work may be found in http://north.east.isi.edu/spt/ audio.html. 6. Internet Research Task Force Reliable Multicast...Adaptation, 4. Multimedia Proxy Caching, 5. Experiments with the Rate Adaptation Protocol (RAP) 6. Providing leadership and innovation to the Internet ... Research Task Force (IRTF) Reliable Multicast Research Group (RMRG) 1. End-to-end Architecture for Quality-adaptive Streaming Applications over the

  10. An Approach to Verification and Validation of a Reliable Multicasting Protocol

    NASA Technical Reports Server (NTRS)

    Callahan, John R.; Montgomery, Todd L.

    1994-01-01

    This paper describes the process of implementing a complex communications protocol that provides reliable delivery of data in multicast-capable, packet-switching telecommunication networks. The protocol, called the Reliable Multicasting Protocol (RMP), was developed incrementally using a combination of formal and informal techniques in an attempt to ensure the correctness of its implementation. Our development process involved three concurrent activities: (1) the initial construction and incremental enhancement of a formal state model of the protocol machine; (2) the initial coding and incremental enhancement of the implementation; and (3) model-based testing of iterative implementations of the protocol. These activities were carried out by two separate teams: a design team and a V&V team. The design team built the first version of RMP with limited functionality to handle only nominal requirements of data delivery. In a series of iterative steps, the design team added new functionality to the implementation while the V&V team kept the state model in fidelity with the implementation. This was done by generating test cases based on suspected errant or offnominal behaviors predicted by the current model. If the execution of a test was different between the model and implementation, then the differences helped identify inconsistencies between the model and implementation. The dialogue between both teams drove the co-evolution of the model and implementation. Testing served as the vehicle for keeping the model and implementation in fidelity with each other. This paper describes (1) our experiences in developing our process model; and (2) three example problems found during the development of RMP.

  11. An approach to verification and validation of a reliable multicasting protocol

    NASA Technical Reports Server (NTRS)

    Callahan, John R.; Montgomery, Todd L.

    1995-01-01

    This paper describes the process of implementing a complex communications protocol that provides reliable delivery of data in multicast-capable, packet-switching telecommunication networks. The protocol, called the Reliable Multicasting Protocol (RMP), was developed incrementally using a combination of formal and informal techniques in an attempt to ensure the correctness of its implementation. Our development process involved three concurrent activities: (1) the initial construction and incremental enhancement of a formal state model of the protocol machine; (2) the initial coding and incremental enhancement of the implementation; and (3) model-based testing of iterative implementations of the protocol. These activities were carried out by two separate teams: a design team and a V&V team. The design team built the first version of RMP with limited functionality to handle only nominal requirements of data delivery. In a series of iterative steps, the design team added new functionality to the implementation while the V&V team kept the state model in fidelity with the implementation. This was done by generating test cases based on suspected errant or off-nominal behaviors predicted by the current model. If the execution of a test was different between the model and implementation, then the differences helped identify inconsistencies between the model and implementation. The dialogue between both teams drove the co-evolution of the model and implementation. Testing served as the vehicle for keeping the model and implementation in fidelity with each other. This paper describes (1) our experiences in developing our process model; and (2) three example problems found during the development of RMP.

  12. Flexible and scalable wavelength multicast of coherent optical OFDM with tolerance against pump phase-noise using reconfigurable coherent multi-carrier pumping.

    PubMed

    Lu, Guo-Wei; Bo, Tianwai; Sakamoto, Takahide; Yamamoto, Naokatsu; Chan, Calvin Chun-Kit

    2016-10-03

    Recently the ever-growing demand for dynamic and high-capacity services in optical networks has resulted in new challenges that require improved network agility and flexibility in order for network resources to become more "consumable" and dynamic, or elastic, in response to requests from higher network layers. Flexible and scalable wavelength conversion or multicast is one of the most important technologies needed for developing agility in the physical layer. This paper will investigate how, using a reconfigurable coherent multi-carrier as a pump, the multicast scalability and the flexibility in wavelength allocation of the converted signals can be effectively improved. Moreover, the coherence in the multiple carriers prevents the phase noise transformation from the local pump to the converted signals, which is imperative for the phase-noise-sensitive multi-level single- or multi-carrier modulated signal. To verify the feasibility of the proposed scheme, we experimentally demonstrate the wavelength multicast of coherent optical orthogonal frequency division multiplexing (CO-OFDM) signals using a reconfigurable coherent multi-carrier pump, showing flexibility in wavelength allocation, scalability in multicast, and tolerance against pump phase noise. Less than 0.5 dB and 1.8 dB power penalties at a bit-error rate (BER) of 10-3 are obtained for the converted CO-OFDM-quadrature phase-shift keying (QPSK) and CO-OFDM-16-ary quadrature amplitude modulation (16QAM) signals, respectively, even when using a distributed feedback laser (DFB) as a pump source. In contrast, with a free-running pumping scheme, the phase noise from DFB pumps severely deteriorates the CO-OFDM signals, resulting in a visible error-floor at a BER of 10-2 in the converted CO-OFDM-16QAM signals.

  13. Chip-set for quality of service support in passive optical networks

    NASA Astrophysics Data System (ADS)

    Ringoot, Edwin; Hoebeke, Rudy; Slabbinck, B. Hans; Verhaert, Michel

    1998-10-01

    In this paper the design of a chip-set for QoS provisioning in ATM-based Passive Optical Networks is discussed. The implementation of a general-purpose switch chip on the Optical Network Unit is presented, with focus on the design of the cell scheduling and buffer management logic. The cell scheduling logic supports `colored' grants, priority jumping and weighted round-robin scheduling. The switch chip offers powerful buffer management capabilities enabling the efficient support of GFR and UBR services. Multicast forwarding is also supported. In addition, the architecture of a MAC controller chip developed for a SuperPON access network is introduced. In particular, the permit scheduling logic and its implementation on the Optical Line Termination will be discussed. The chip-set enables the efficient support of services with different service requirements on the SuperPON. The permit scheduling logic built into the MAC controller chip in combination with the cell scheduling and buffer management capabilities of the switch chip can be used by network operators to offer guaranteed service performance to delay sensitive services, and to efficiently and fairly distribute any spare capacity to delay insensitive services.

  14. Overview of AMS (CCSDS Asynchronous Message Service)

    NASA Technical Reports Server (NTRS)

    Burleigh, Scott

    2006-01-01

    This viewgraph presentation gives an overview of the Consultative Committee for Space Data Systems (CCSDS) Asynchronous Message Service (AMS). The topics include: 1) Key Features; 2) A single AMS continuum; 3) The AMS Protocol Suite; 4) A multi-continuum venture; 5) Constraining transmissions; 6) Security; 7) Fault Tolerance; 8) Performance of Reference Implementation; 9) AMS vs Multicast (1); 10) AMS vs Multicast (2); 11) RAMS testing exercise; and 12) Results.

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

    Ishihara, T

    Currently, the problem at hand is in distributing identical copies of OEP and filter software to a large number of farm nodes. One of the common methods used to transfer these softwares is through unicast. Unicast protocol faces the problem of repetitiously sending the same data over the network. Since the sending rate is limited, this process poses to be a bottleneck. Therefore, one possible solution to this problem lies in creating a reliable multicast protocol. A specific type of multicast protocol is the Bulk Multicast Protocol [4]. This system consists of one sender distributing data to many receivers. Themore » sender delivers data at a given rate of data packets. In response to that, the receiver replies to the sender with a status packet which contains information about the packet loss in terms of Negative Acknowledgment. The probability of the status packet sent back to the sender is+, where N is the number of receivers. The protocol is designed to have approximately 1 status packet for each data packet sent. In this project, we were able to show that the time taken for the complete transfer of a file to multiple receivers was about 12 times faster with multicast than by the use of unicast. The implementation of this experimental protocol shows remarkable improvement in mass data transfer to a large number of farm machines.« less

  16. Apply network coding for H.264/SVC multicasting

    NASA Astrophysics Data System (ADS)

    Wang, Hui; Kuo, C.-C. Jay

    2008-08-01

    In a packet erasure network environment, video streaming benefits from error control in two ways to achieve graceful degradation. The first approach is application-level (or the link-level) forward error-correction (FEC) to provide erasure protection. The second error control approach is error concealment at the decoder end to compensate lost packets. A large amount of research work has been done in the above two areas. More recently, network coding (NC) techniques have been proposed for efficient data multicast over networks. It was shown in our previous work that multicast video streaming benefits from NC for its throughput improvement. An algebraic model is given to analyze the performance in this work. By exploiting the linear combination of video packets along nodes in a network and the SVC video format, the system achieves path diversity automatically and enables efficient video delivery to heterogeneous receivers in packet erasure channels. The application of network coding can protect video packets against the erasure network environment. However, the rank defficiency problem of random linear network coding makes the error concealment inefficiently. It is shown by computer simulation that the proposed NC video multicast scheme enables heterogenous receiving according to their capacity constraints. But it needs special designing to improve the video transmission performance when applying network coding.

  17. Multicast Parametric Synchronous Sampling

    DTIC Science & Technology

    2011-09-01

    enhancement in a parametric mixer device. Fig. 4 shows the principle of generating uniform, high quality replicas extending over previously un-attainable...critical part of the MPASS architecture and is responsible for the direct and continuous acquisition of data across all of the multicast signal copies...ii) ability to copy THz signals with impunity to tens of replicas ; (iii) all-optical delays > 1.9 us; (iv) 10’s of THz-fast all-optical sampling of

  18. 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.

  19. AF-TRUST, Air Force Team for Research in Ubiquitous Secure Technology

    DTIC Science & Technology

    2010-07-26

    Charles Sutton, J. D. Tygar, and Kai Xia. Book chapter in Jeffrey J. P. Tsai and Philip S. Yu (eds.) Machine Learning in Cyber Trust: Security, Privacy...enterprise, tactical, embedded systems and command and control levels. From these studies, commissioned by Dr . Sekar Chandersekaran of the Secretary of the...Data centers avoid IP Multicast because of a series of problems with the technology. • Dr . Multicast (the MCMD), a system that maps traditional I PMC

  20. Secure Hierarchical Multicast Routing and Multicast Internet Anonymity

    DTIC Science & Technology

    1998-06-01

    Multimedia, Summer 94, pages 76{79, 94. [15] David Chaum . Blind signatures for untraceable payments. In Proc. Crypto󈨖, pages 199{203, 1982. [16] David L...use of digital signatures , which consist of a cryptographic hash of the message encrypted with the private key of the signer. Digitally-signed messages... signature on the request and on the certi cate it contains. Notice that the location service need not retrieve the initiator’s public key as it is contained

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

    Ennis, G.; Lala, T.K.

    This document presents the results of a study undertaken by First Pacific Networks as part of EPRI Project RP-3567-01 regarding the support of broadcast services within the EPRI Utility Communications Architecture (UCA) protocols and the use of such services by UCA applications. This report has focused on the requirements and architectural implications of broadcast within UCA. A subsequent phase of this project is to develop specific recommendations for extending CUA so as to support broadcast. The conclusions of this report are presented in Section 5. The authors summarize the major conclusions as follows: broadcast and multicast support would be verymore » useful within UCA, not only for utility-specific applications but also simply to support the network engineering of a large-scale communications system, in this regard, UCA is no different from other large network systems which have found broadcast and multicast to be of substantial benefit for a variety of system management purposes; the primary architectural impact of broadcast and multicast falls on the UCA network level (which would need to be enhanced) and the UCA application level (which would be the user of broadcast); there is a useful subset of MMS services which could take advantage of broadcast; the UCA network level would need to be enhanced both in the areas of addressing and routing so as to properly support broadcast. A subsequent analysis will be required to define the specific enhancements to UCA required to support broadcast and multicast.« less

  2. CLON: Overlay Networks and Gossip Protocols for Cloud Environments

    NASA Astrophysics Data System (ADS)

    Matos, Miguel; Sousa, António; Pereira, José; Oliveira, Rui; Deliot, Eric; Murray, Paul

    Although epidemic or gossip-based multicast is a robust and scalable approach to reliable data dissemination, its inherent redundancy results in high resource consumption on both links and nodes. This problem is aggravated in settings that have costlier or resource constrained links as happens in Cloud Computing infrastructures composed by several interconnected data centers across the globe.

  3. A Security Architecture for Fault-Tolerant Systems

    DTIC Science & Technology

    1993-06-03

    aspect of our effort to achieve better performance is integrating the system into microkernel -based operating systems. 4 Summary and discussion In...135-171, June 1983. [vRBC+92] R. van Renesse, K. Birman, R. Cooper, B. Glade, and P. Stephenson. Reliable multicast between microkernels . In...Proceedings of the USENIX Microkernels and Other Kernel Architectures Workshop, April 1992. 29

  4. Back pressure based multicast scheduling for fair bandwidth allocation.

    PubMed

    Sarkar, Saswati; Tassiulas, Leandros

    2005-09-01

    We study the fair allocation of bandwidth in multicast networks with multirate capabilities. In multirate transmission, each source encodes its signal in layers. The lowest layer contains the most important information and all receivers of a session should receive it. If a receiver's data path has additional bandwidth, it receives higher layers which leads to a better quality of reception. The bandwidth allocation objective is to distribute the layers fairly. We present a computationally simple, decentralized scheduling policy that attains the maxmin fair rates without using any knowledge of traffic statistics and layer bandwidths. This policy learns the congestion level from the queue lengths at the nodes, and adapts the packet transmissions accordingly. When the network is congested, packets are dropped from the higher layers; therefore, the more important lower layers suffer negligible packet loss. We present analytical and simulation results that guarantee the maxmin fairness of the resulting rate allocation, and upper bound the packet loss rates for different layers.

  5. Secure Multicast Tree Structure Generation Method for Directed Diffusion Using A* Algorithms

    NASA Astrophysics Data System (ADS)

    Kim, Jin Myoung; Lee, Hae Young; Cho, Tae Ho

    The application of wireless sensor networks to areas such as combat field surveillance, terrorist tracking, and highway traffic monitoring requires secure communication among the sensor nodes within the networks. Logical key hierarchy (LKH) is a tree based key management model which provides secure group communication. When a sensor node is added or evicted from the communication group, LKH updates the group key in order to ensure the security of the communications. In order to efficiently update the group key in directed diffusion, we propose a method for secure multicast tree structure generation, an extension to LKH that reduces the number of re-keying messages by considering the addition and eviction ratios of the history data. For the generation of the proposed key tree structure the A* algorithm is applied, in which the branching factor at each level can take on different value. The experiment results demonstrate the efficiency of the proposed key tree structure against the existing key tree structures of fixed branching factors.

  6. Multicasting for all-optical multifiber networks

    NASA Astrophysics Data System (ADS)

    Kã¶Ksal, Fatih; Ersoy, Cem

    2007-02-01

    All-optical wavelength-routed WDM WANs can support the high bandwidth and the long session duration requirements of the application scenarios such as interactive distance learning or on-line diagnosis of patients simultaneously in different hospitals. However, multifiber and limited sparse light splitting and wavelength conversion capabilities of switches result in a difficult optimization problem. We attack this problem using a layered graph model. The problem is defined as a k-edge-disjoint degree-constrained Steiner tree problem for routing and fiber and wavelength assignment of k multicasts. A mixed integer linear programming formulation for the problem is given, and a solution using CPLEX is provided. However, the complexity of the problem grows quickly with respect to the number of edges in the layered graph, which depends on the number of nodes, fibers, wavelengths, and multicast sessions. Hence, we propose two heuristics layered all-optical multicast algorithm [(LAMA) and conservative fiber and wavelength assignment (C-FWA)] to compare with CPLEX, existing work, and unicasting. Extensive computational experiments show that LAMA's performance is very close to CPLEX, and it is significantly better than existing work and C-FWA for nearly all metrics, since LAMA jointly optimizes routing and fiber-wavelength assignment phases compared with the other candidates, which attack the problem by decomposing two phases. Experiments also show that important metrics (e.g., session and group blocking probability, transmitter wavelength, and fiber conversion resources) are adversely affected by the separation of two phases. Finally, the fiber-wavelength assignment strategy of C-FWA (Ex-Fit) uses wavelength and fiber conversion resources more effectively than the First Fit.

  7. A framework using cluster-based hybrid network architecture for collaborative virtual surgery.

    PubMed

    Qin, Jing; Choi, Kup-Sze; Poon, Wai-Sang; Heng, Pheng-Ann

    2009-12-01

    Research on collaborative virtual environments (CVEs) opens the opportunity for simulating the cooperative work in surgical operations. It is however a challenging task to implement a high performance collaborative surgical simulation system because of the difficulty in maintaining state consistency with minimum network latencies, especially when sophisticated deformable models and haptics are involved. In this paper, an integrated framework using cluster-based hybrid network architecture is proposed to support collaborative virtual surgery. Multicast transmission is employed to transmit updated information among participants in order to reduce network latencies, while system consistency is maintained by an administrative server. Reliable multicast is implemented using distributed message acknowledgment based on cluster cooperation and sliding window technique. The robustness of the framework is guaranteed by the failure detection chain which enables smooth transition when participants join and leave the collaboration, including normal and involuntary leaving. Communication overhead is further reduced by implementing a number of management approaches such as computational policies and collaborative mechanisms. The feasibility of the proposed framework is demonstrated by successfully extending an existing standalone orthopedic surgery trainer into a collaborative simulation system. A series of experiments have been conducted to evaluate the system performance. The results demonstrate that the proposed framework is capable of supporting collaborative surgical simulation.

  8. On compensation of four wave mixing effect in dispersion managed hybrid WDM-OTDM multicast overlay system with optical phase conjugation modules

    NASA Astrophysics Data System (ADS)

    Singh, Sukhbir; Singh, Surinder

    2017-11-01

    This paper investigated the effect of FWM and its suppression using optical phase conjugation modules in dispersion managed hybrid WDM-OTDM multicast overlay system. Interaction between propagating wavelength signals at higher power level causes new FWM component generation that can significant limit the system performance. OPC module consists of the pump signal and 0.6 km HNLF implemented in midway of optical link to generate destructive phase FWM components. Investigation revealed that by use of even OPC module in optical link reduces the FWM power and mitigate the interaction between wavelength signals at variable signal input power, dispersion parameter (β2) and transmission distance. System performance comparison is also made between without DM-OPC module, with DM and with DM-OPC module in scenario of FWM tolerance. The BER performance of hybrid WDM-OTDM multicast system using OPC module is improved by multiplication factor of 2 as comparable to dispersion managed and coverage distance is increased by factor of 2 as in Singh and Singh (2016).

  9. Hybrid ARQ Scheme with Autonomous Retransmission for Multicasting in Wireless Sensor Networks.

    PubMed

    Jung, Young-Ho; Choi, Jihoon

    2017-02-25

    A new hybrid automatic repeat request (HARQ) scheme for multicast service for wireless sensor networks is proposed in this study. In the proposed algorithm, the HARQ operation is combined with an autonomous retransmission method that ensure a data packet is transmitted irrespective of whether or not the packet is successfully decoded at the receivers. The optimal number of autonomous retransmissions is determined to ensure maximum spectral efficiency, and a practical method that adjusts the number of autonomous retransmissions for realistic conditions is developed. Simulation results show that the proposed method achieves higher spectral efficiency than existing HARQ techniques.

  10. A Loss Tolerant Rate Controller for Reliable Multicast

    NASA Technical Reports Server (NTRS)

    Montgomery, Todd

    1997-01-01

    This paper describes the design, specification, and performance of a Loss Tolerant Rate Controller (LTRC) for use in controlling reliable multicast senders. The purpose of this rate controller is not to adapt to congestion (or loss) on a per loss report basis (such as per received negative acknowledgment), but instead to use loss report information and perceived state to decide more prudent courses of action for both the short and long term. The goal of this controller is to be responsive to congestion, but not overly reactive to spurious independent loss. Performance of the controller is verified through simulation results.

  11. Efficient File Sharing by Multicast - P2P Protocol Using Network Coding and Rank Based Peer Selection

    NASA Technical Reports Server (NTRS)

    Stoenescu, Tudor M.; Woo, Simon S.

    2009-01-01

    In this work, we consider information dissemination and sharing in a distributed peer-to-peer (P2P highly dynamic communication network. In particular, we explore a network coding technique for transmission and a rank based peer selection method for network formation. The combined approach has been shown to improve information sharing and delivery to all users when considering the challenges imposed by the space network environments.

  12. MDP: Reliable File Transfer for Space Missions

    NASA Technical Reports Server (NTRS)

    Rash, James; Criscuolo, Ed; Hogie, Keith; Parise, Ron; Hennessy, Joseph F. (Technical Monitor)

    2002-01-01

    This paper presents work being done at NASA/GSFC by the Operating Missions as Nodes on the Internet (OMNI) project to demonstrate the application of the Multicast Dissemination Protocol (MDP) to space missions to reliably transfer files. This work builds on previous work by the OMNI project to apply Internet communication technologies to space communication. The goal of this effort is to provide an inexpensive, reliable, standard, and interoperable mechanism for transferring files in the space communication environment. Limited bandwidth, noise, delay, intermittent connectivity, link asymmetry, and one-way links are all possible issues for space missions. Although these are link-layer issues, they can have a profound effect on the performance of transport and application level protocols. MDP, a UDP-based reliable file transfer protocol, was designed for multicast environments which have to address these same issues, and it has done so successfully. Developed by the Naval Research Lab in the mid 1990's, MDP is now in daily use by both the US Post Office and the DoD. This paper describes the use of MDP to provide automated end-to-end data flow for space missions. It examines the results of a parametric study of MDP in a simulated space link environment and discusses the results in terms of their implications for space missions. Lessons learned are addressed, which suggest minor enhancements to the MDP user interface to add specific features for space mission requirements, such as dynamic control of data rate, and a checkpoint/resume capability. These are features that are provided for in the protocol, but are not implemented in the sample MDP application that was provided. A brief look is also taken at the status of standardization. A version of MDP known as NORM (Neck Oriented Reliable Multicast) is in the process of becoming an IETF standard.

  13. Development of a Web-Based Distributed Interactive Simulation (DIS) Environment Using JavaScript

    DTIC Science & Technology

    2014-09-01

    scripting that let users change or interact with web content depending on user input, which is in contrast with server-side scripts such as PHP, Java and...transfer, DIS usually broadcasts or multicasts its PDUs based on UDP socket. 3. JavaScript JavaScript is the scripting language of the web, and all...IDE) for developing desktop, mobile and web applications with JAVA , C++, HTML5, JavaScript and more. b. Framework The DIS implementation of

  14. Research on Collaborative Technology in Distributed Virtual Reality System

    NASA Astrophysics Data System (ADS)

    Lei, ZhenJiang; Huang, JiJie; Li, Zhao; Wang, Lei; Cui, JiSheng; Tang, Zhi

    2018-01-01

    Distributed virtual reality technology applied to the joint training simulation needs the CSCW (Computer Supported Cooperative Work) terminal multicast technology to display and the HLA (high-level architecture) technology to ensure the temporal and spatial consistency of the simulation, in order to achieve collaborative display and collaborative computing. In this paper, the CSCW’s terminal multicast technology has been used to modify and expand the implementation framework of HLA. During the simulation initialization period, this paper has used the HLA statement and object management service interface to establish and manage the CSCW network topology, and used the HLA data filtering mechanism for each federal member to establish the corresponding Mesh tree. During the simulation running period, this paper has added a new thread for the RTI and the CSCW real-time multicast interactive technology into the RTI, so that the RTI can also use the window message mechanism to notify the application update the display screen. Through many applications of submerged simulation training in substation under the operation of large power grid, it is shown that this paper has achieved satisfactory training effect on the collaborative technology used in distributed virtual reality simulation.

  15. IPTV multicast with peer-assisted lossy error control

    NASA Astrophysics Data System (ADS)

    Li, Zhi; Zhu, Xiaoqing; Begen, Ali C.; Girod, Bernd

    2010-07-01

    Emerging IPTV technology uses source-specific IP multicast to deliver television programs to end-users. To provide reliable IPTV services over the error-prone DSL access networks, a combination of multicast forward error correction (FEC) and unicast retransmissions is employed to mitigate the impulse noises in DSL links. In existing systems, the retransmission function is provided by the Retransmission Servers sitting at the edge of the core network. In this work, we propose an alternative distributed solution where the burden of packet loss repair is partially shifted to the peer IP set-top boxes. Through Peer-Assisted Repair (PAR) protocol, we demonstrate how the packet repairs can be delivered in a timely, reliable and decentralized manner using the combination of server-peer coordination and redundancy of repairs. We also show that this distributed protocol can be seamlessly integrated with an application-layer source-aware error protection mechanism called forward and retransmitted Systematic Lossy Error Protection (SLEP/SLEPr). Simulations show that this joint PARSLEP/ SLEPr framework not only effectively mitigates the bottleneck experienced by the Retransmission Servers, thus greatly enhancing the scalability of the system, but also efficiently improves the resistance to the impulse noise.

  16. Saguaro: A Distributed Operating System Based on Pools of Servers.

    DTIC Science & Technology

    1988-03-25

    asynchronous message passing, multicast, and semaphores are supported. We have found this flexibility to be very useful for distributed programming. The...variety of communication primitives provided by SR has facilitated the research of Stella Atkins, who was a visiting professor at Arizona during Spring...data bits in a raw communication channel to help keep the source and destination synchronized , Psync explicitly embeds timing information drawn from the

  17. Finding idle machines in a workstation-based distributed system

    NASA Technical Reports Server (NTRS)

    Theimer, Marvin M.; Lantz, Keith A.

    1989-01-01

    The authors describe the design and performance of scheduling facilities for finding idle hosts in a workstation-based distributed system. They focus on the tradeoffs between centralized and decentralized architectures with respect to scalability, fault tolerance, and simplicity of design, as well as several implementation issues of interest when multicast communication is used. They conclude that the principal tradeoff between the two approaches is that a centralized architecture can be scaled to a significantly greater degree and can more easily monitor global system statistics, whereas a decentralized architecture is simpler to implement.

  18. Toward fidelity between specification and implementation

    NASA Technical Reports Server (NTRS)

    Callahan, John R.; Montgomery, Todd L.; Morrison, Jeff; Wu, Yunqing

    1994-01-01

    This paper describes the methods used to specify and implement a complex communications protocol that provides reliable delivery of data in multicast-capable, packet-switching telecommunication networks. The protocol, called the Reliable Multicasting Protocol (RMP), was developed incrementally by two complementary teams using a combination of formal and informal techniques in an attempt to ensure the correctness of the protocol implementation. The first team, called the Design team, initially specified protocol requirements using a variant of SCR requirements tables and implemented a prototype solution. The second team, called the V&V team, developed a state model based on the requirements tables and derived test cases from these tables to exercise the implementation. In a series of iterative steps, the Design team added new functionality to the implementation while the V&V team kept the state model in fidelity with the implementation through testing. Test cases derived from state transition paths in the formal model formed the dialogue between teams during development and served as the vehicles for keeping the model and implementation in fidelity with each other. This paper describes our experiences in developing our process model, details of our approach, and some example problems found during the development of RMP.

  19. Design and Implementation of the MARG Human Body Motion Tracking System

    DTIC Science & Technology

    2004-10-01

    7803-8463-6/041$20.00 ©:!004 IEEE 625 OPTOTRAK from Northern Digital Inc. is a typical example of a marker-based system [I 0]. Another is the...technique called tunneling is :used to overcome this problem. Tunneling is a software solution that runs on the end point routers/computers and allows...multicast packets to traverse the network by putting them into unicast packets. MUTUP overcomes the tunneling problem using shared memory in the

  20. Admission and Preventive Load Control for Delivery of Multicast and Broadcast Services via S-UMTS

    NASA Astrophysics Data System (ADS)

    Angelou, E.; Koutsokeras, N.; Andrikopoulos, I.; Mertzanis, I.; Karaliopoulos, M.; Henrio, P.

    2003-07-01

    An Admission Control strategy is proposed for unidirectional satellite systems delivering multicast and broadcast services to mobile users. In such systems, both the radio interface and the targeted services impose particular requirements on the RRM task. We briefly discuss the RRM requirements that stem from the services point of view and from the features of the SATIN access scheme that differentiate it from the conventional T-UMTS radio interface. The main functional entities of RRM and the alternative modes of operation are outlined and the proposed Admission Control algorithm is described in detail. The results from the simulation study that demonstrate its performance for a number of different scenarios are finally presented and conclusions derived.

  1. Space Flight Middleware: Remote AMS over DTN for Delay-Tolerant Messaging

    NASA Technical Reports Server (NTRS)

    Burleigh, Scott

    2011-01-01

    This paper describes a technique for implementing scalable, reliable, multi-source multipoint data distribution in space flight communications -- Delay-Tolerant Reliable Multicast (DTRM) -- that is fully supported by the "Remote AMS" (RAMS) protocol of the Asynchronous Message Service (AMS) proposed for standardization within the Consultative Committee for Space Data Systems (CCSDS). The DTRM architecture enables applications to easily "publish" messages that will be reliably and efficiently delivered to an arbitrary number of "subscribing" applications residing anywhere in the space network, whether in the same subnet or in a subnet on a remote planet or vehicle separated by many light minutes of interplanetary space. The architecture comprises multiple levels of protocol, each included for a specific purpose and allocated specific responsibilities: "application AMS" traffic performs end-system data introduction and delivery subject to access control; underlying "remote AMS" directs this application traffic to populations of recipients at remote locations in a multicast distribution tree, enabling the architecture to scale up to large networks; further underlying Delay-Tolerant Networking (DTN) Bundle Protocol (BP) advances RAMS protocol data units through the distribution tree using delay-tolerant storeand- forward methods; and further underlying reliable "convergence-layer" protocols ensure successful data transfer over each segment of the end-to-end route. The result is scalable, reliable, delay-tolerant multi-source multicast that is largely self-configuring.

  2. Dynamic Network Selection for Multicast Services in Wireless Cooperative Networks

    NASA Astrophysics Data System (ADS)

    Chen, Liang; Jin, Le; He, Feng; Cheng, Hanwen; Wu, Lenan

    In next generation mobile multimedia communications, different wireless access networks are expected to cooperate. However, it is a challenging task to choose an optimal transmission path in this scenario. This paper focuses on the problem of selecting the optimal access network for multicast services in the cooperative mobile and broadcasting networks. An algorithm is proposed, which considers multiple decision factors and multiple optimization objectives. An analytic hierarchy process (AHP) method is applied to schedule the service queue and an artificial neural network (ANN) is used to improve the flexibility of the algorithm. Simulation results show that by applying the AHP method, a group of weight ratios can be obtained to improve the performance of multiple objectives. And ANN method is effective to adaptively adjust weight ratios when users' new waiting threshold is generated.

  3. Polarization-insensitive PAM-4-carrying free-space orbital angular momentum (OAM) communications.

    PubMed

    Liu, Jun; Wang, Jian

    2016-02-22

    We present a simple configuration incorporating single polarization-sensitive phase-only liquid crystal spatial light modulator (SLM) to facilitate polarization-insensitive free-space optical communications employing orbital angular momentum (OAM) modes. We experimentally demonstrate several polarization-insensitive optical communication subsystems by propagating a single OAM mode, multicasting 4 and 10 OAM modes, and multiplexing 8 OAM modes, respectively. Free-space polarization-insensitive optical communication links using OAM modes that carry four-level pulse-amplitude modulation (PAM-4) signal are demonstrated in the experiment. The observed optical signal-to-noise ratio (OSNR) penalties are less than 1 dB in both polarization-insensitive N-fold OAM modes multicasting and multiple OAM modes multiplexing at a bit-error rate (BER) of 2e-3 (enhanced forward-error correction (EFEC) threshold).

  4. An approach to verification and validation of a reliable multicasting protocol: Extended Abstract

    NASA Technical Reports Server (NTRS)

    Callahan, John R.; Montgomery, Todd L.

    1995-01-01

    This paper describes the process of implementing a complex communications protocol that provides reliable delivery of data in multicast-capable, packet-switching telecommunication networks. The protocol, called the Reliable Multicasting Protocol (RMP), was developed incrementally using a combination of formal and informal techniques in an attempt to ensure the correctness of its implementation. Our development process involved three concurrent activities: (1) the initial construction and incremental enhancement of a formal state model of the protocol machine; (2) the initial coding and incremental enhancement of the implementation; and (3) model-based testing of iterative implementations of the protocol. These activities were carried out by two separate teams: a design team and a V&V team. The design team built the first version of RMP with limited functionality to handle only nominal requirements of data delivery. This initial version did not handle off-nominal cases such as network partitions or site failures. Meanwhile, the V&V team concurrently developed a formal model of the requirements using a variant of SCR-based state tables. Based on these requirements tables, the V&V team developed test cases to exercise the implementation. In a series of iterative steps, the design team added new functionality to the implementation while the V&V team kept the state model in fidelity with the implementation. This was done by generating test cases based on suspected errant or off-nominal behaviors predicted by the current model. If the execution of a test in the model and implementation agreed, then the test either found a potential problem or verified a required behavior. However, if the execution of a test was different in the model and implementation, then the differences helped identify inconsistencies between the model and implementation. In either case, the dialogue between both teams drove the co-evolution of the model and implementation. We have found that this interactive, iterative approach to development allows software designers to focus on delivery of nominal functionality while the V&V team can focus on analysis of off nominal cases. Testing serves as the vehicle for keeping the model and implementation in fidelity with each other. This paper describes (1) our experiences in developing our process model; and (2) three example problems found during the development of RMP. Although RMP has provided our research effort with a rich set of test cases, it also has practical applications within NASA. For example, RMP is being considered for use in the NASA EOSDIS project due to its significant performance benefits in applications that need to replicate large amounts of data to many network sites.

  5. Security Enhancement Using Cache Based Reauthentication in WiMAX Based E-Learning System

    PubMed Central

    Rajagopal, Chithra; Bhuvaneshwaran, Kalaavathi

    2015-01-01

    WiMAX networks are the most suitable for E-Learning through their Broadcast and Multicast Services at rural areas. Authentication of users is carried out by AAA server in WiMAX. In E-Learning systems the users must be forced to perform reauthentication to overcome the session hijacking problem. The reauthentication of users introduces frequent delay in the data access which is crucial in delaying sensitive applications such as E-Learning. In order to perform fast reauthentication caching mechanism known as Key Caching Based Authentication scheme is introduced in this paper. Even though the cache mechanism requires extra storage to keep the user credentials, this type of mechanism reduces the 50% of the delay occurring during reauthentication. PMID:26351658

  6. Security Enhancement Using Cache Based Reauthentication in WiMAX Based E-Learning System.

    PubMed

    Rajagopal, Chithra; Bhuvaneshwaran, Kalaavathi

    2015-01-01

    WiMAX networks are the most suitable for E-Learning through their Broadcast and Multicast Services at rural areas. Authentication of users is carried out by AAA server in WiMAX. In E-Learning systems the users must be forced to perform reauthentication to overcome the session hijacking problem. The reauthentication of users introduces frequent delay in the data access which is crucial in delaying sensitive applications such as E-Learning. In order to perform fast reauthentication caching mechanism known as Key Caching Based Authentication scheme is introduced in this paper. Even though the cache mechanism requires extra storage to keep the user credentials, this type of mechanism reduces the 50% of the delay occurring during reauthentication.

  7. Distributed Ship Navigation Control System Based on Dual Network

    NASA Astrophysics Data System (ADS)

    Yao, Ying; Lv, Wu

    2017-10-01

    Navigation system is very important for ship’s normal running. There are a lot of devices and sensors in the navigation system to guarantee ship’s regular work. In the past, these devices and sensors were usually connected via CAN bus for high performance and reliability. However, as the development of related devices and sensors, the navigation system also needs the ability of high information throughput and remote data sharing. To meet these new requirements, we propose the communication method based on dual network which contains CAN bus and industrial Ethernet. Also, we import multiple distributed control terminals with cooperative strategy based on the idea of synchronizing the status by multicasting UDP message contained operation timestamp to make the system more efficient and reliable.

  8. Digital Multicasting of Multiple Audio Streams

    NASA Technical Reports Server (NTRS)

    Macha, Mitchell; Bullock, John

    2007-01-01

    The Mission Control Center Voice Over Internet Protocol (MCC VOIP) system (see figure) comprises hardware and software that effect simultaneous, nearly real-time transmission of as many as 14 different audio streams to authorized listeners via the MCC intranet and/or the Internet. The original version of the MCC VOIP system was conceived to enable flight-support personnel located in offices outside a spacecraft mission control center to monitor audio loops within the mission control center. Different versions of the MCC VOIP system could be used for a variety of public and commercial purposes - for example, to enable members of the general public to monitor one or more NASA audio streams through their home computers, to enable air-traffic supervisors to monitor communication between airline pilots and air-traffic controllers in training, and to monitor conferences among brokers in a stock exchange. At the transmitting end, the audio-distribution process begins with feeding the audio signals to analog-to-digital converters. The resulting digital streams are sent through the MCC intranet, using a user datagram protocol (UDP), to a server that converts them to encrypted data packets. The encrypted data packets are then routed to the personal computers of authorized users by use of multicasting techniques. The total data-processing load on the portion of the system upstream of and including the encryption server is the total load imposed by all of the audio streams being encoded, regardless of the number of the listeners or the number of streams being monitored concurrently by the listeners. The personal computer of a user authorized to listen is equipped with special- purpose MCC audio-player software. When the user launches the program, the user is prompted to provide identification and a password. In one of two access- control provisions, the program is hard-coded to validate the user s identity and password against a list maintained on a domain-controller computer at the MCC. In the other access-control provision, the program verifies that the user is authorized to have access to the audio streams. Once both access-control checks are completed, the audio software presents a graphical display that includes audiostream-selection buttons and volume-control sliders. The user can select all or any subset of the available audio streams and can adjust the volume of each stream independently of that of the other streams. The audio-player program spawns a "read" process for the selected stream(s). The spawned process sends, to the router(s), a "multicast-join" request for the selected streams. The router(s) responds to the request by sending the encrypted multicast packets to the spawned process. The spawned process receives the encrypted multicast packets and sends a decryption packet to audio-driver software. As the volume or muting features are changed by the user, interrupts are sent to the spawned process to change the corresponding attributes sent to the audio-driver software. The total latency of this system - that is, the total time from the origination of the audio signals to generation of sound at a listener s computer - lies between four and six seconds.

  9. Scalable Active Optical Access Network Using Variable High-Speed PLZT Optical Switch/Splitter

    NASA Astrophysics Data System (ADS)

    Ashizawa, Kunitaka; Sato, Takehiro; Tokuhashi, Kazumasa; Ishii, Daisuke; Okamoto, Satoru; Yamanaka, Naoaki; Oki, Eiji

    This paper proposes a scalable active optical access network using high-speed Plumbum Lanthanum Zirconate Titanate (PLZT) optical switch/splitter. The Active Optical Network, called ActiON, using PLZT switching technology has been presented to increase the number of subscribers and the maximum transmission distance, compared to the Passive Optical Network (PON). ActiON supports the multicast slot allocation realized by running the PLZT switch elements in the splitter mode, which forces the switch to behave as an optical splitter. However, the previous ActiON creates a tradeoff between the network scalability and the power loss experienced by the optical signal to each user. It does not use the optical power efficiently because the optical power is simply divided into 0.5 to 0.5 without considering transmission distance from OLT to each ONU. The proposed network adopts PLZT switch elements in the variable splitter mode, which controls the split ratio of the optical power considering the transmission distance from OLT to each ONU, in addition to PLZT switch elements in existing two modes, the switching mode and the splitter mode. The proposed network introduces the flexible multicast slot allocation according to the transmission distance from OLT to each user and the number of required users using three modes, while keeping the advantages of ActiON, which are to support scalable and secure access services. Numerical results show that the proposed network dramatically reduces the required number of slots and supports high bandwidth efficiency services and extends the coverage of access network, compared to the previous ActiON, and the required computation time for selecting multicast users is less than 30msec, which is acceptable for on-demand broadcast services.

  10. DDS as middleware of the Southern African Large Telescope control system

    NASA Astrophysics Data System (ADS)

    Maartens, Deneys S.; Brink, Janus D.

    2016-07-01

    The Southern African Large Telescope (SALT) software control system1 is realised as a distributed control system, implemented predominantly in National Instruments' LabVIEW. The telescope control subsystems communicate using cyclic, state-based messages. Currently, transmitting a message is accomplished by performing an HTTP PUT request to a WebDAV directory on a centralised Apache web server, while receiving is based on polling the web server for new messages. While the method works, it presents a number of drawbacks; a scalable distributed communication solution with minimal overhead is a better fit for control systems. This paper describes our exploration of the Data Distribution Service (DDS). DDS is a formal standard specification, defined by the Object Management Group (OMG), that presents a data-centric publish-subscribe model for distributed application communication and integration. It provides an infrastructure for platform- independent many-to-many communication. A number of vendors provide implementations of the DDS standard; RTI, in particular, provides a DDS toolkit for LabVIEW. This toolkit has been evaluated against the needs of SALT, and a few deficiencies have been identified. We have developed our own implementation that interfaces LabVIEW to DDS in order to address our specific needs. Our LabVIEW DDS interface implementation is built against the RTI DDS Core component, provided by RTI under their Open Community Source licence. Our needs dictate that the interface implementation be platform independent. Since we have access to the RTI DDS Core source code, we are able to build the RTI DDS libraries for any of the platforms on which we require support. The communications functionality is based on UDP multicasting. Multicasting is an efficient communications mechanism with low overheads which avoids duplicated point-to-point transmission of data on a network where there are multiple recipients of the data. In the paper we present a performance evaluation of DDS against the current HTTP-based implementation as well as the historical DataSocket implementation. We conclude with a summary and describe future work.

  11. 47 CFR 73.1201 - Station identification.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... offerings. Television and Class A television broadcast stations may make these announcements visually or... multicast audio programming streams, in a manner that appropriately alerts its audience to the fact that it is listening to a digital audio broadcast. No other insertion between the station's call letters and...

  12. The Development of Interactive Distance Learning in Taiwan: Challenges and Prospects.

    ERIC Educational Resources Information Center

    Chu, Clarence T.

    1999-01-01

    Describes three types of interactive distance-education systems under development in Taiwan: real-time multicast systems; virtual-classroom systems; and curriculum-on-demand systems. Discusses the use of telecommunications and computer technology in higher education, problems and challenges, and future prospects. (Author/LRW)

  13. Australian DefenceScience. Volume 16, Number 1, Autumn

    DTIC Science & Technology

    2008-01-01

    are carried via VOIP technology, and multicast IP traffic for audio -visual communications is also supported. The SSATIN system overall is seen to...Artificial Intelligence and Soft Computing Palma de Mallorca, Spain http://iasted.com/conferences/home-628.html 1 - 3 Sep 2008 Visualisation , Imaging and

  14. Application of the fractional Fourier transform to the design of LCOS based optical interconnects and fiber switches.

    PubMed

    Robertson, Brian; Zhang, Zichen; Yang, Haining; Redmond, Maura M; Collings, Neil; Liu, Jinsong; Lin, Ruisheng; Jeziorska-Chapman, Anna M; Moore, John R; Crossland, William A; Chu, D P

    2012-04-20

    It is shown that reflective liquid crystal on silicon (LCOS) spatial light modulator (SLM) based interconnects or fiber switches that use defocus to reduce crosstalk can be evaluated and optimized using a fractional Fourier transform if certain optical symmetry conditions are met. Theoretically the maximum allowable linear hologram phase error compared to a Fourier switch is increased by a factor of six before the target crosstalk for telecom applications of -40 dB is exceeded. A Gerchberg-Saxton algorithm incorporating a fractional Fourier transform modified for use with a reflective LCOS SLM is used to optimize multi-casting holograms in a prototype telecom switch. Experiments are in close agreement to predicted performance.

  15. QoS Adaptation in Multimedia Multicast Conference Applications for E-Learning Services

    ERIC Educational Resources Information Center

    Deusdado, Sérgio; Carvalho, Paulo

    2006-01-01

    The evolution of the World Wide Web service has incorporated new distributed multimedia conference applications, powering a new generation of e-learning development and allowing improved interactivity and prohuman relations. Groupware applications are increasingly representative in the Internet home applications market, however, the Quality of…

  16. Internet technologies and requirements for telemedicine

    NASA Technical Reports Server (NTRS)

    Lamaster, H.; Meylor, J.; Meylor, F.

    1997-01-01

    Internet technologies are briefly introduced and those applicable for telemedicine are reviewed. Multicast internet technologies are described. The National Aeronautics and Space Administration (NASA) 'Telemedicine Space-bridge to Russia' project is described and used to derive requirements for internet telemedicine. Telemedicine privacy and Quality of Service (QoS) requirements are described.

  17. 47 CFR 76.66 - Satellite broadcast signal carriage.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... free over-the-air signal, including multicast and high definition digital signals. (c) Election cycle... first retransmission consent-mandatory carriage election cycle shall be for a four-year period... carriage election cycle, and all cycles thereafter, shall be for a period of three years (e.g. the second...

  18. 47 CFR 73.1201 - Station identification.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...; Provided, That the name of the licensee, the station's frequency, the station's channel number, as stated... number in the station identification must use the station's major channel number and may distinguish multicast program streams. For example, a DTV station with major channel number 26 may use 26.1 to identify...

  19. 47 CFR 73.1201 - Station identification.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...; Provided, That the name of the licensee, the station's frequency, the station's channel number, as stated... number in the station identification must use the station's major channel number and may distinguish multicast program streams. For example, a DTV station with major channel number 26 may use 26.1 to identify...

  20. 47 CFR 73.1201 - Station identification.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...; Provided, That the name of the licensee, the station's frequency, the station's channel number, as stated... number in the station identification must use the station's major channel number and may distinguish multicast program streams. For example, a DTV station with major channel number 26 may use 26.1 to identify...

  1. 47 CFR 73.1201 - Station identification.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...; Provided, That the name of the licensee, the station's frequency, the station's channel number, as stated... number in the station identification must use the station's major channel number and may distinguish multicast program streams. For example, a DTV station with major channel number 26 may use 26.1 to identify...

  2. The Development of CyberLearning in Dual-Mode: Higher Education Institutions in Taiwan.

    ERIC Educational Resources Information Center

    Chen, Yau Jane

    2002-01-01

    Open and distance education in Taiwan has evolved into cyberlearning. Over half (56 percent) of the conventional universities and colleges have been upgraded to dual-mode institutions offering real-time multicast instructional systems using videoconferencing, cable television, virtual classrooms, and curriculum-on-demand systems. The Ministry of…

  3. Digital Video and the Internet: A Powerful Combination.

    ERIC Educational Resources Information Center

    Barron, Ann E.; Orwig, Gary W.

    1995-01-01

    Provides an overview of digital video and outlines hardware and software necessary for interactive training on the World Wide Web and for videoconferences via the Internet. Lists sites providing additional information on digital video, on CU-SeeMe software, and on MBONE (Multicast BackBONE), a technology that permits real-time transmission of…

  4. 78 FR 53757 - Information Collections Being Submitted for Review and Approval to the Office of Management and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-30

    ...'s channel number, as stated on the station's license, and/or the station's network affiliation may... Stations, choosing to include the station's channel number in the station identification must use the station's major channel number and may distinguish multicast program streams. For example, a DTV station...

  5. Multimedia C for Remote Language Teaching over SuperJANET.

    ERIC Educational Resources Information Center

    Matthews, E.; And Others

    1996-01-01

    Describes work carried out as part of a remote language teaching research investigation, which is looking into the use of multicast, multimedia conferencing over SuperJANET. The fundamental idea is to investigate the feasibility of sharing language teaching resources among universities within the United Kingdom by using the broadband SuperJANET…

  6. 37 CFR 386.2 - Royalty fee for secondary transmission by satellite carriers.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... BOARD, LIBRARY OF CONGRESS RATES AND TERMS FOR STATUTORY LICENSES ADJUSTMENT OF ROYALTY FEES FOR... a given month. (2) In the case of a station engaged in digital multicasting, the rates set forth in paragraph (b) of this section shall apply to each digital stream that a satellite carrier or distributor...

  7. 37 CFR 386.2 - Royalty fee for secondary transmission by satellite carriers.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... BOARD, LIBRARY OF CONGRESS RATES AND TERMS FOR STATUTORY LICENSES ADJUSTMENT OF ROYALTY FEES FOR... a given month. (2) In the case of a station engaged in digital multicasting, the rates set forth in paragraph (b) of this section shall apply to each digital stream that a satellite carrier or distributor...

  8. 75 FR 53198 - Rate Adjustment for the Satellite Carrier Compulsory License

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-31

    ... LIBRARY OF CONGRESS Copyright Royalty Board 37 CFR Part 386 [Docket No. 2010-4 CRB Satellite Rate] Rate Adjustment for the Satellite Carrier Compulsory License AGENCY: Copyright Royalty Board, Library... last day of a given month. (2) In the case of a station engaged in digital multicasting, the rates set...

  9. 37 CFR 386.2 - Royalty fee for secondary transmission by satellite carriers.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... BOARD, LIBRARY OF CONGRESS RATES AND TERMS FOR STATUTORY LICENSES ADJUSTMENT OF ROYALTY FEES FOR... a given month. (2) In the case of a station engaged in digital multicasting, the rates set forth in paragraph (b) of this section shall apply to each digital stream that a satellite carrier or distributor...

  10. 37 CFR 386.2 - Royalty fee for secondary transmission by satellite carriers.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... BOARD, LIBRARY OF CONGRESS RATES AND TERMS FOR STATUTORY LICENSES ADJUSTMENT OF ROYALTY FEES FOR... a given month. (2) In the case of a station engaged in digital multicasting, the rates set forth in paragraph (b) of this section shall apply to each digital stream that a satellite carrier or distributor...

  11. Multipoint Multimedia Conferencing System with Group Awareness Support and Remote Management

    ERIC Educational Resources Information Center

    Osawa, Noritaka; Asai, Kikuo

    2008-01-01

    A multipoint, multimedia conferencing system called FocusShare is described that uses IPv6/IPv4 multicasting for real-time collaboration, enabling video, audio, and group awareness information to be shared. Multiple telepointers provide group awareness information and make it easy to share attention and intention. In addition to pointing with the…

  12. Cooperation and information replication in wireless networks.

    PubMed

    Poularakis, Konstantinos; Tassiulas, Leandros

    2016-03-06

    A significant portion of today's network traffic is due to recurring downloads of a few popular contents. It has been observed that replicating the latter in caches installed at network edges-close to users-can drastically reduce network bandwidth usage and improve content access delay. Such caching architectures are gaining increasing interest in recent years as a way of dealing with the explosive traffic growth, fuelled further by the downward slope in storage space price. In this work, we provide an overview of caching with a particular emphasis on emerging network architectures that enable caching at the radio access network. In this context, novel challenges arise due to the broadcast nature of the wireless medium, which allows simultaneously serving multiple users tuned into a multicast stream, and the mobility of the users who may be frequently handed off from one cell tower to another. Existing results indicate that caching at the wireless edge has a great potential in removing bottlenecks on the wired backbone networks. Taking into consideration the schedule of multicast service and mobility profiles is crucial to extract maximum benefit in network performance. © 2016 The Author(s).

  13. Design alternatives for process group membership and multicast

    NASA Technical Reports Server (NTRS)

    Birman, Kenneth P.; Cooper, Robert; Gleeson, Barry

    1991-01-01

    Process groups are a natural tool for distributed programming, and are increasingly important in distributed computing environments. However, there is little agreement on the most appropriate semantics for process group membership and group communication. These issues are of special importance in the Isis system, a toolkit for distributed programming. Isis supports several styles of process group, and a collection of group communication protocols spanning a range of atomicity and ordering properties. This flexibility makes Isis adaptable to a variety of applications, but is also a source of complexity that limits performance. This paper reports on a new architecture that arose from an effort to simplify Isis process group semantics. Our findings include a refined notion of how the clients of a group should be treated, what the properties of a multicast primitive should be when systems contain large numbers of overlapping groups, and a new construct called the casuality domain. As an illustration, we apply the architecture to the problem of converting processes into fault-tolerant process groups in a manner that is 'transparent' to other processes in the system.

  14. Integer-Linear-Programing Optimization in Scalable Video Multicast with Adaptive Modulation and Coding in Wireless Networks

    PubMed Central

    Lee, Chaewoo

    2014-01-01

    The advancement in wideband wireless network supports real time services such as IPTV and live video streaming. However, because of the sharing nature of the wireless medium, efficient resource allocation has been studied to achieve a high level of acceptability and proliferation of wireless multimedia. Scalable video coding (SVC) with adaptive modulation and coding (AMC) provides an excellent solution for wireless video streaming. By assigning different modulation and coding schemes (MCSs) to video layers, SVC can provide good video quality to users in good channel conditions and also basic video quality to users in bad channel conditions. For optimal resource allocation, a key issue in applying SVC in the wireless multicast service is how to assign MCSs and the time resources to each SVC layer in the heterogeneous channel condition. We formulate this problem with integer linear programming (ILP) and provide numerical results to show the performance under 802.16 m environment. The result shows that our methodology enhances the overall system throughput compared to an existing algorithm. PMID:25276862

  15. Enabling Optical Network Test Bed for 5G Tests

    NASA Astrophysics Data System (ADS)

    Giuntini, Marco; Grazioso, Paolo; Matera, Francesco; Valenti, Alessandro; Attanasio, Vincenzo; Di Bartolo, Silvia; Nastri, Emanuele

    2017-03-01

    In this work, we show some experimental approaches concerning optical network design dedicated to 5G infrastructures. In particular, we show some implementations of network slicing based on Carrier Ethernet forwarding, which will be very suitable in the context of 5G heterogeneous networks, especially looking at services for vertical enterprises. We also show how to adopt a central unit (orchestrator) to automatically manage such logical paths according to quality-of-service requirements, which can be monitored at the user location. We also illustrate how novel all-optical processes, such as the ones based on all-optical wavelength conversion, can be used for multicasting, enabling development of TV broadcasting based on 4G-5G terminals. These managing and forwarding techniques, operating on optical links, are tested in a wireless environment on Wi-Fi cells and emulating LTE and WiMAX systems by means of the NS-3 code.

  16. 75 FR 52267 - Waiver of Statement of Account Filing Deadline for the 2010/1 Period

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-25

    ... available in a print format, a PDF format, and a software ``fill-in'' format created by Gralin Associates... retransmission of multicast streams. The paper and PDF versions of the form have been available to cable... recognize that the paper and PDF versions of the SOA have been available since July, many large and small...

  17. High Performance Computing Multicast

    DTIC Science & Technology

    2012-02-01

    responsiveness, first-tier applications often implement replicated in- memory key-value stores , using them to store state or to cache data from services...alternative that replicates data , combines agreement on update ordering with amnesia freedom, and supports both good scalability and fast response. A...alternative that replicates data , combines agreement on update ordering with amnesia freedom, and supports both good scalability and fast response

  18. 77 FR 65596 - Self-Regulatory Organizations; The NASDAQ Stock Market LLC; Notice of Filing of Proposed Rule...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-29

    ... to offer remote multi-cast ITCH Wave Ports for clients co-located at other third party data centers... delivery of third party market data to market center clients via a wireless network using millimeter wave... Multi- cast ITCH Wave Ports for clients co-located at other third-party data centers, through which...

  19. Design and Implementation of Replicated Object Layer

    NASA Technical Reports Server (NTRS)

    Koka, Sudhir

    1996-01-01

    One of the widely used techniques for construction of fault tolerant applications is the replication of resources so that if one copy fails sufficient copies may still remain operational to allow the application to continue to function. This thesis involves the design and implementation of an object oriented framework for replicating data on multiple sites and across different platforms. Our approach, called the Replicated Object Layer (ROL) provides a mechanism for consistent replication of data over dynamic networks. ROL uses the Reliable Multicast Protocol (RMP) as a communication protocol that provides for reliable delivery, serialization and fault tolerance. Besides providing type registration, this layer facilitates distributed atomic transactions on replicated data. A novel algorithm called the RMP Commit Protocol, which commits transactions efficiently in reliable multicast environment is presented. ROL provides recovery procedures to ensure that site and communication failures do not corrupt persistent data, and male the system fault tolerant to network partitions. ROL will facilitate building distributed fault tolerant applications by performing the burdensome details of replica consistency operations, and making it completely transparent to the application.Replicated databases are a major class of applications which could be built on top of ROL.

  20. Detecting and Preventing Sybil Attacks in Wireless Sensor Networks Using Message Authentication and Passing Method.

    PubMed

    Dhamodharan, Udaya Suriya Raj Kumar; Vayanaperumal, Rajamani

    2015-01-01

    Wireless sensor networks are highly indispensable for securing network protection. Highly critical attacks of various kinds have been documented in wireless sensor network till now by many researchers. The Sybil attack is a massive destructive attack against the sensor network where numerous genuine identities with forged identities are used for getting an illegal entry into a network. Discerning the Sybil attack, sinkhole, and wormhole attack while multicasting is a tremendous job in wireless sensor network. Basically a Sybil attack means a node which pretends its identity to other nodes. Communication to an illegal node results in data loss and becomes dangerous in the network. The existing method Random Password Comparison has only a scheme which just verifies the node identities by analyzing the neighbors. A survey was done on a Sybil attack with the objective of resolving this problem. The survey has proposed a combined CAM-PVM (compare and match-position verification method) with MAP (message authentication and passing) for detecting, eliminating, and eventually preventing the entry of Sybil nodes in the network. We propose a scheme of assuring security for wireless sensor network, to deal with attacks of these kinds in unicasting and multicasting.

  1. Detecting and Preventing Sybil Attacks in Wireless Sensor Networks Using Message Authentication and Passing Method

    PubMed Central

    Dhamodharan, Udaya Suriya Raj Kumar; Vayanaperumal, Rajamani

    2015-01-01

    Wireless sensor networks are highly indispensable for securing network protection. Highly critical attacks of various kinds have been documented in wireless sensor network till now by many researchers. The Sybil attack is a massive destructive attack against the sensor network where numerous genuine identities with forged identities are used for getting an illegal entry into a network. Discerning the Sybil attack, sinkhole, and wormhole attack while multicasting is a tremendous job in wireless sensor network. Basically a Sybil attack means a node which pretends its identity to other nodes. Communication to an illegal node results in data loss and becomes dangerous in the network. The existing method Random Password Comparison has only a scheme which just verifies the node identities by analyzing the neighbors. A survey was done on a Sybil attack with the objective of resolving this problem. The survey has proposed a combined CAM-PVM (compare and match-position verification method) with MAP (message authentication and passing) for detecting, eliminating, and eventually preventing the entry of Sybil nodes in the network. We propose a scheme of assuring security for wireless sensor network, to deal with attacks of these kinds in unicasting and multicasting. PMID:26236773

  2. RIACS

    NASA Technical Reports Server (NTRS)

    Oliger, Joseph

    1997-01-01

    Topics considered include: high-performance computing; cognitive and perceptual prostheses (computational aids designed to leverage human abilities); autonomous systems. Also included: development of a 3D unstructured grid code based on a finite volume formulation and applied to the Navier-stokes equations; Cartesian grid methods for complex geometry; multigrid methods for solving elliptic problems on unstructured grids; algebraic non-overlapping domain decomposition methods for compressible fluid flow problems on unstructured meshes; numerical methods for the compressible navier-stokes equations with application to aerodynamic flows; research in aerodynamic shape optimization; S-HARP: a parallel dynamic spectral partitioner; numerical schemes for the Hamilton-Jacobi and level set equations on triangulated domains; application of high-order shock capturing schemes to direct simulation of turbulence; multicast technology; network testbeds; supercomputer consolidation project.

  3. A Novel Group Coordination Protocol for Collaborative Multimedia Systems

    DTIC Science & Technology

    1998-01-01

    technology have advanced considerably, ef- ficient group coordination support for applications characterized by synchronous and wide-area groupwork is...As a component within a general coordination architecture for many-to-many groupwork , floor control coexists with proto- cols for reliable ordered...multicast and media synchronization at a sub-application level. Orchestration of multiparty groupwork with fine-grained and fair floor control is an

  4. 78 FR 19051 - Self-Regulatory Organizations; The NASDAQ Stock Market LLC; Notice of Filing and Immediate...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-28

    ... that is in test mode in excess of one. (c)-(f) No change. (g) Other Port Fees Remote Multi-cast ITCH... environment to test upcoming NASDAQ releases and product enhancements, as well as test software prior to... public in accordance with the provisions of 5 U.S.C. 552, will be available for Web site viewing and...

  5. Multiuser Transmit Beamforming for Maximum Sum Capacity in Tactical Wireless Multicast Networks

    DTIC Science & Technology

    2006-08-01

    commonly used extended Kalman filter . See [2, 5, 6] for recent tutorial overviews. In particle filtering , continuous distributions are approximated by...signals (using and developing associated particle filtering tools). Our work on these topics has been reported in seven (IEEE, SIAM) journal papers and...multidimensional scaling, tracking, intercept, particle filters . 16. PRICE CODE 17. SECURITY CLASSIFICATION OF REPORT 18. SECURITY CLASSIFICATION OF

  6. Remote Observing and Automatic FTP on Kitt Peak

    NASA Astrophysics Data System (ADS)

    Seaman, Rob; Bohannan, Bruce

    As part of KPNO's Internet-based observing services we experimented with the publically available audio, video and whiteboard MBONE clients (vat, nv, wb and others) in both point-to-point and multicast modes. While bandwidth is always a constraint on the Internet, it is less of a constraint to operations than many might think. These experiments were part of two new Internet-based observing services offered to KPNO observers beginning with the Fall 1995 semester: a remote observing station and an automatic FTP data queue. The remote observing station seeks to duplicate the KPNO IRAF/ICE observing environment on a workstation at the observer's home institution. The automatic FTP queue is intended to support those observing programs that require quick transport of data back to the home institution, for instance, for near real time reductions to aid in observing tactics. We also discuss the early operational results of these services.

  7. Enhanced Performance & Functionality of Tunable Delay Lines

    DTIC Science & Technology

    2012-08-01

    Figure 6. Experimental setup. Transmitter is capable of generating 80-Gb/s RZ-DQPSK, 40-Gb/s RZ-DPSK and 40-Gb/s RZ-OOK modulation formats. Phase...Power penalty with respect to B2B of each channel for 2-, 4-, 8-fold multicasting. (c) Pulsewidth as a function of DGD along with eye diagrams of 2...63 Figure 99. Concept. (a) A distributed optical network ; (b) NOLMs for

  8. Scalable Technology for a New Generation of Collaborative Applications

    DTIC Science & Technology

    2007-04-01

    of the International Symposium on Distributed Computing (DISC), Cracow, Poland, September 2005. Classic Paxos vs. Fast Paxos: Caveat Emptor, Flavio...grou or able and fast multicast primitive to layer under high-level latency across dimensions as varied as group size [10, 17],abstractions such as...servers, networked via fast , dedicated interconnects. The system to subscribe to a fraction of the equities on the software stack running on a single

  9. Extensible Interest Management for Scalable Persistent Distributed Virtual Environments

    DTIC Science & Technology

    1999-12-01

    Calvin, Cebula et al. 1995; Morse, Bic et al. 2000) uses a two grid, with each grid cell having two multicast addresses. An entity expresses interest...Entity distribution for experimental runs 78 s I * • ...... ^..... * * a» Sis*«*»* 1 ***** Jj |r...Multiple Users and Shared Applications with VRML. VRML 97, Monterey, CA. pp. 33-40. Calvin, J. O., D. P. Cebula , et al. (1995). Data Subscription in

  10. Improved Lower Bounds on the Price of Stability of Undirected Network Design Games

    NASA Astrophysics Data System (ADS)

    Bilò, Vittorio; Caragiannis, Ioannis; Fanelli, Angelo; Monaco, Gianpiero

    Bounding the price of stability of undirected network design games with fair cost allocation is a challenging open problem in the Algorithmic Game Theory research agenda. Even though the generalization of such games in directed networks is well understood in terms of the price of stability (it is exactly H n , the n-th harmonic number, for games with n players), far less is known for network design games in undirected networks. The upper bound carries over to this case as well while the best known lower bound is 42/23 ≈ 1.826. For more restricted but interesting variants of such games such as broadcast and multicast games, sublogarithmic upper bounds are known while the best known lower bound is 12/7 ≈ 1.714. In the current paper, we improve the lower bounds as follows. We break the psychological barrier of 2 by showing that the price of stability of undirected network design games is at least 348/155 ≈ 2.245. Our proof uses a recursive construction of a network design game with a simple gadget as the main building block. For broadcast and multicast games, we present new lower bounds of 20/11 ≈ 1.818 and 1.862, respectively.

  11. A Fair Contention Access Scheme for Low-Priority Traffic in Wireless Body Area Networks

    PubMed Central

    Sajeel, Muhammad; Bashir, Faisal; Asfand-e-yar, Muhammad; Tauqir, Muhammad

    2017-01-01

    Recently, wireless body area networks (WBANs) have attracted significant consideration in ubiquitous healthcare. A number of medium access control (MAC) protocols, primarily derived from the superframe structure of the IEEE 802.15.4, have been proposed in literature. These MAC protocols aim to provide quality of service (QoS) by prioritizing different traffic types in WBANs. A contention access period (CAP)with high contention in priority-based MAC protocols can result in higher number of collisions and retransmissions. During CAP, traffic classes with higher priority are dominant over low-priority traffic; this has led to starvation of low-priority traffic, thus adversely affecting WBAN throughput, delay, and energy consumption. Hence, this paper proposes a traffic-adaptive priority-based superframe structure that is able to reduce contention in the CAP period, and provides a fair chance for low-priority traffic. Simulation results in ns-3 demonstrate that the proposed MAC protocol, called traffic- adaptive priority-based MAC (TAP-MAC), achieves low energy consumption, high throughput, and low latency compared to the IEEE 802.15.4 standard, and the most recent priority-based MAC protocol, called priority-based MAC protocol (PA-MAC). PMID:28832495

  12. An Evaluation of the Network Efficiency Required in Order to Support Multicast and Synchronous Distributed Learning Network Traffic

    DTIC Science & Technology

    2003-09-01

    This restriction limits the deployment to small and medium sized enterprises. The Internet cannot universally use DVMRP for this reason. In addition...20503. 1. AGENCY USE ONLY (Leave blank) 2. REPORT DATE September 2003 3. REPORT TYPE AND DATES COVERED Master’s Thesis 4. TITLE... University , 1996 Submitted in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE IN COMPUTER SCIENCE from

  13. Traffic Generator (TrafficGen) Version 1.4.2: Users Guide

    DTIC Science & Technology

    2016-06-01

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

  14. GUMP: Adapting Client/Server Messaging Protocols into Peer-to-Peer Serverless Environments

    DTIC Science & Technology

    2010-06-11

    and other related metadata, such as message re- ceiver ID (for supporting multiple connections) and so forth. The Proxy consumes the message and uses...the underlying discovery subsystem and multicast to process the message and translate the request into behaviour suitable for the un- derlying...communication i.e. a chat. Jingle (XEP-0166) [26] is a related specification that de- fines an extension to the XMPP protocol for initiating and

  15. Tactical Mobile Communications (Communications tactiques mobiles)

    DTIC Science & Technology

    1999-11-01

    13]. randomly at the network nodes. Each multicast group Our studies do, in fact, support this conjecture. consists of the source node plus at least...Capability investigate the MMR concept in some more detail. The study was contracted to a group which Multi-role denotes the capability to support a...through the HW- and SW-resources of the frontends can be incorporated in a task-dedicated GPU. Functions can be grouped into four categories: MMR

  16. Multimedia Data Capture with Multicast Dissemination for Online Distance Learning

    DTIC Science & Technology

    2001-12-01

    Juan Gril and Dr. Don Brutzman to wrap the multiple videos in a user- friendly environment. The web pages also contain the original PowerPoint...this CD, Juan Gril , a volunteer for the Siggraph 2001 Online Committee, created web pages that match the style and functionality desired by the...leader. The Committee for 2001 consisted of Don Brutzman, Stephen. Matsuba, Mike Collins, Allen Dutton, Juan Gril , Mike Hunsberger, Jerry Isdale

  17. The Impact on Quality of Service When Using Security-Enabling Filters to Provide for the Security of Run-Time Virtual Environments

    DTIC Science & Technology

    2002-09-01

    Secure Multicast......................................................................24 i. Message Digests and Message Authentication Codes ( MACs ...that is, the needs of the VE will determine what the design will look like (e.g., reliable vs . unreliable data communications). In general, there...Molva00] and [Abdalla00]. i. Message Digests and Message Authentication Codes ( MACs ) Message digests and MACs are used for data integrity verification

  18. Robust Airborne Networking Extensions (RANGE)

    DTIC Science & Technology

    2008-02-01

    IMUNES [13] project, which provides an entire network stack virtualization and topology control inside a single FreeBSD machine . The emulated topology...Multicast versus broadcast in a manet.” in ADHOC-NOW, 2004, pp. 14–27. [9] J. Mukherjee, R. Atwood , “ Rendezvous point relocation in protocol independent...computer with an Ethernet connection, or a Linux virtual machine on some other (e.g., Windows) operating system, should work. 2.1 Patching the source code

  19. Polling-Based High-Bit-Rate Packet Transfer in a Microcellular Network to Allow Fast Terminals

    NASA Astrophysics Data System (ADS)

    Hoa, Phan Thanh; Lambertsen, Gaute; Yamada, Takahiko

    A microcellular network will be a good candidate for the future broadband mobile network. It is expected to support high-bit-rate connection for many fast mobile users if the handover is processed fast enough to lessen its impact on QoS requirements. One of the promising techniques is believed to use for the wireless interface in such a microcellular network is the WLAN (Wireless LAN) technique due to its very high wireless channel rate. However, the less capability of mobility support of this technique must be improved to be able to expand its utilization for the microcellular environment. The reason of its less support mobility is large handover latency delay caused by contention-based handover to the new BS (base station) and delay of re-forwarding data from the old to new BS. This paper presents a proposal of multi-polling and dynamic LMC (Logical Macro Cell) to reduce mentioned above delays. Polling frame for an MT (Mobile Terminal) is sent from every BS belonging to the same LMC — a virtual single macro cell that is a multicast group of several adjacent micro-cells in which an MT is communicating. Instead of contending for the medium of a new BS during handover, the MT responds to the polling sent from that new BS to enable the transition. Because only one BS of the LMC receives the polling ACK (acknowledgement) directly from the MT, this ACK frame has to be multicast to all BSs of the same LMC through the terrestrial network to continue sending the next polling cycle at each BS. Moreover, when an MT hands over to a new cell, its current LMC is switched over to a newly corresponding LMC to prevent the future contending for a new LMC. By this way, an MT can do handover between micro-cells of an LMC smoothly because the redundant resource is reserved for it at neighboring cells, no need to contend with others. Our simulation results using the OMNeT++ simulator illustrate the performance achievements of the multi-polling and dynamic LMC scheme in eliminating handover latency, packet loss and keeping mobile users' throughput stable in the high traffic load condition though it causes somewhat overhead on the neighboring cells.

  20. NASA Exhibits

    NASA Technical Reports Server (NTRS)

    Deardorff, Glenn; Djomehri, M. Jahed; Freeman, Ken; Gambrel, Dave; Green, Bryan; Henze, Chris; Hinke, Thomas; Hood, Robert; Kiris, Cetin; Moran, Patrick; hide

    2001-01-01

    A series of NASA presentations for the Supercomputing 2001 conference are summarized. The topics include: (1) Mars Surveyor Landing Sites "Collaboratory"; (2) Parallel and Distributed CFD for Unsteady Flows with Moving Overset Grids; (3) IP Multicast for Seamless Support of Remote Science; (4) Consolidated Supercomputing Management Office; (5) Growler: A Component-Based Framework for Distributed/Collaborative Scientific Visualization and Computational Steering; (6) Data Mining on the Information Power Grid (IPG); (7) Debugging on the IPG; (8) Debakey Heart Assist Device: (9) Unsteady Turbopump for Reusable Launch Vehicle; (10) Exploratory Computing Environments Component Framework; (11) OVERSET Computational Fluid Dynamics Tools; (12) Control and Observation in Distributed Environments; (13) Multi-Level Parallelism Scaling on NASA's Origin 1024 CPU System; (14) Computing, Information, & Communications Technology; (15) NAS Grid Benchmarks; (16) IPG: A Large-Scale Distributed Computing and Data Management System; and (17) ILab: Parameter Study Creation and Submission on the IPG.

  1. Priority arbitration mechanism

    DOEpatents

    Garmire, Derrick L [Kingston, NY; Herring, Jay R [Poughkeepsie, NY; Stunkel, Craig B [Bethel, CT

    2007-03-06

    A method is provided for selecting a data source for transmission on one of several logical (virtual) lanes embodied in a single physical connection. Lanes are assigned to either a high priority class or to a low priority class. One of six conditions is employed to determine when re-arbitration of lane priorities is desired. When this occurs a next source for transmission is selected based on a the specification of the maximum number of high priority packets that can be sent after a lower priority transmission has been interrupted. Alternatively, a next source for transmission is selected based on a the specification of the maximum number of high priority packets that can be sent while a lower priority packet is waiting. If initialized correctly, the arbiter keeps all of the packets of a high priority packet contiguous, while allowing lower priority packets to be interrupted by the higher priority packets, but not to the point of starvation of the lower priority packets.

  2. Collaboration Services: Enabling Chat in Disadvantaged Grids

    DTIC Science & Technology

    2014-06-01

    grids in the tactical domain" [2]. The main focus of this group is to identify what we call tactical SOA foundation services. By this we mean which...Here, only IPv4 is supported, as differences relating to IPv4 and IPv6 addressing meant that this functionality was not easily extended to use IPv6 ...multicast groups. Our IPv4 implementation is fully compliant with the specification, whereas the IPv6 implementation uses our own interpretation of

  3. A Secure Group Communication Architecture for a Swarm of Autonomous Unmanned Aerial Vehicles

    DTIC Science & Technology

    2008-03-01

    members to use the same decryption key. This shared decryption key is called the Session Encryption Key ( SEK ) or Traffic Encryption Key (TEK...Since everyone shares the SEK , members need to hold additional Key Encryption Keys (KEK) that are used to securely distribute the SEK to each valid...managing this process. To preserve the secrecy of the multicast data, the SEK needs to be updated upon certain events such as a member joining and

  4. Network connectivity enhancement by exploiting all optical multicast in semiconductor ring laser

    NASA Astrophysics Data System (ADS)

    Siraj, M.; Memon, M. I.; Shoaib, M.; Alshebeili, S.

    2015-03-01

    The use of smart phone and tablet applications will provide the troops for executing, controlling and analyzing sophisticated operations with the commanders providing crucial documents directly to troops wherever and whenever needed. Wireless mesh networks (WMNs) is a cutting edge networking technology which is capable of supporting Joint Tactical radio System (JTRS).WMNs are capable of providing the much needed bandwidth for applications like hand held radios and communication for airborne and ground vehicles. Routing management tasks can be efficiently handled through WMNs through a central command control center. As the spectrum space is congested, cognitive radios are a much welcome technology that will provide much needed bandwidth. They can self-configure themselves, can adapt themselves to the user requirement, provide dynamic spectrum access for minimizing interference and also deliver optimal power output. Sometimes in the indoor environment, there are poor signal issues and reduced coverage. In this paper, a solution utilizing (CR WMNs) over optical network is presented by creating nanocells (PCs) inside the indoor environment. The phenomenon of four-wave mixing (FWM) is exploited to generate all-optical multicast using semiconductor ring laser (SRL). As a result same signal is transmitted at different wavelengths. Every PC is assigned a unique wavelength. By using CR technology in conjunction with PC will not only solve network coverage issue but will provide a good bandwidth to the secondary users.

  5. Unidata LDM-7: a Hybrid Multicast/unicast System for Highly Efficient and Reliable Real-Time Data Distribution

    NASA Astrophysics Data System (ADS)

    Emmerson, S. R.; Veeraraghavan, M.; Chen, S.; Ji, X.

    2015-12-01

    Results of a pilot deployment of a major new version of the Unidata Local Data Manager (LDM-7) are presented. The Unidata LDM was developed by the University Corporation for Atmospheric Research (UCAR) and comprises a suite of software for the distribution and local processing of data in near real-time. It is widely used in the geoscience community to distribute observational data and model output, most notably as the foundation of the Unidata Internet Data Distribution (IDD) system run by UCAR, but also in private networks operated by NOAA, NASA, USGS, etc. The current version, LDM-6, uses at least one unicast TCP connection per receiving host. With over 900 connections, the bit-rate of total outgoing IDD traffic from UCAR averages approximately 3.0 GHz, with peak data rates exceeding 6.6 GHz. Expected increases in data volume suggest that a more efficient distribution mechanism will be required in the near future. LDM-7 greatly reduces the outgoing bandwidth requirement by incorporating a recently-developed "semi-reliable" IP multicast protocol while retaining the unicast TCP mechanism for reliability. During the summer of 2015, UCAR and the University of Virginia conducted a pilot deployment of the Unidata LDM-7 among U.S. university participants with access to the Internet2 network. Results of this pilot program, along with comparisons to the existing Unidata LDM-6 system, are presented.

  6. Research on performance of three-layer MG-OXC system based on MLAG and OCDM

    NASA Astrophysics Data System (ADS)

    Wang, Yubao; Ren, Yanfei; Meng, Ying; Bai, Jian

    2017-10-01

    At present, as traffic volume which optical transport networks convey and species of traffic grooming methods increase rapidly, optical switching techniques are faced with a series of issues, such as more requests for the number of wavelengths and complicated structure management and implementation. This work introduces optical code switching based on wavelength switching, constructs the three layers multi-granularity optical cross connection (MG-OXC) system on the basis of optical code division multiplexing (OCDM) and presents a new traffic grooming algorithm. The proposed architecture can improve the flexibility of traffic grooming, reduce the amount of used wavelengths and save the number of consumed ports, hence, it can simplify routing device and enhance the performance of the system significantly. Through analyzing the network model of switching structure on multicast layered auxiliary graph (MLAG) and the establishment of traffic grooming links, and the simulation of blocking probability and throughput, this paper shows the excellent performance of this mentioned architecture.

  7. Optical signal processing techniques and applications of optical phase modulation in high-speed communication systems

    NASA Astrophysics Data System (ADS)

    Deng, Ning

    In recent years, optical phase modulation has attracted much research attention in the field of fiber optic communications. Compared with the traditional optical intensity-modulated signal, one of the main merits of the optical phase-modulated signal is the better transmission performance. For optical phase modulation, in spite of the comprehensive study of its transmission performance, only a little research has been carried out in terms of its functions, applications and signal processing for future optical networks. These issues are systematically investigated in this thesis. The research findings suggest that optical phase modulation and its signal processing can greatly facilitate flexible network functions and high bandwidth which can be enjoyed by end users. In the thesis, the most important physical-layer technology, signal processing and multiplexing, are investigated with optical phase-modulated signals. Novel and advantageous signal processing and multiplexing approaches are proposed and studied. Experimental investigations are also reported and discussed in the thesis. Optical time-division multiplexing and demultiplexing. With the ever-increasing demand on communication bandwidth, optical time division multiplexing (OTDM) is an effective approach to upgrade the capacity of each wavelength channel in current optical systems. OTDM multiplexing can be simply realized, however, the demultiplexing requires relatively complicated signal processing and stringent timing control, and thus hinders its practicability. To tackle this problem, in this thesis a new OTDM scheme with hybrid DPSK and OOK signals is proposed. Experimental investigation shows this scheme can greatly enhance the demultiplexing timing misalignment and improve the demultiplexing performance, and thus make OTDM more practical and cost effective. All-optical signal processing. In current and future optical communication systems and networks, the data rate per wavelength has been approaching the speed limitation of electronics. Thus, all-optical signal processing techniques are highly desirable to support the necessary optical switching functionalities in future ultrahigh-speed optical packet-switching networks. To cope with the wide use of optical phase-modulated signals, in the thesis, an all-optical logic for DPSK or PSK input signals is developed, for the first time. Based on four-wave mixing in semiconductor optical amplifier, the structure of the logic gate is simple, compact, and capable of supporting ultrafast operation. In addition to the general logic processing, a simple label recognition scheme, as a specific signal processing function, is proposed for phase-modulated label signals. The proposed scheme can recognize any incoming label pattern according to the local pattern, and is potentially capable of handling variable-length label patterns. Optical access network with multicast overlay and centralized light sources. In the arena of optical access networks, wavelength division multiplexing passive optical network (WDM-PON) is a promising technology to deliver high-speed data traffic. However, most of proposed WDM-PONs only support conventional point-to-point service, and cannot meet the requirement of increasing demand on broadcast and multicast service. In this thesis, a simple network upgrade is proposed based on the traditional PON architecture to support both point-to-point and multicast service. In addition, the two service signals are modulated on the same lightwave carrier. The upstream signal is also remodulated on the same carrier at the optical network unit, which can significantly relax the requirement on wavelength management at the network unit.

  8. Parallel and Distributed Methods for Constrained Nonconvex Optimization—Part I: Theory

    NASA Astrophysics Data System (ADS)

    Scutari, Gesualdo; Facchinei, Francisco; Lampariello, Lorenzo

    2017-04-01

    In Part I of this paper, we proposed and analyzed a novel algorithmic framework for the minimization of a nonconvex (smooth) objective function, subject to nonconvex constraints, based on inner convex approximations. This Part II is devoted to the application of the framework to some resource allocation problems in communication networks. In particular, we consider two non-trivial case-study applications, namely: (generalizations of) i) the rate profile maximization in MIMO interference broadcast networks; and the ii) the max-min fair multicast multigroup beamforming problem in a multi-cell environment. We develop a new class of algorithms enjoying the following distinctive features: i) they are \\emph{distributed} across the base stations (with limited signaling) and lead to subproblems whose solutions are computable in closed form; and ii) differently from current relaxation-based schemes (e.g., semidefinite relaxation), they are proved to always converge to d-stationary solutions of the aforementioned class of nonconvex problems. Numerical results show that the proposed (distributed) schemes achieve larger worst-case rates (resp. signal-to-noise interference ratios) than state-of-the-art centralized ones while having comparable computational complexity.

  9. Automation Hooks Architecture Trade Study for Flexible Test Orchestration

    NASA Technical Reports Server (NTRS)

    Lansdowne, Chatwin A.; Maclean, John R.; Graffagnino, Frank J.; McCartney, Patrick A.

    2010-01-01

    We describe the conclusions of a technology and communities survey supported by concurrent and follow-on proof-of-concept prototyping to evaluate feasibility of defining a durable, versatile, reliable, visible software interface to support strategic modularization of test software development. The objective is that test sets and support software with diverse origins, ages, and abilities can be reliably integrated into test configurations that assemble and tear down and reassemble with scalable complexity in order to conduct both parametric tests and monitored trial runs. The resulting approach is based on integration of three recognized technologies that are currently gaining acceptance within the test industry and when combined provide a simple, open and scalable test orchestration architecture that addresses the objectives of the Automation Hooks task. The technologies are automated discovery using multicast DNS Zero Configuration Networking (zeroconf), commanding and data retrieval using resource-oriented Restful Web Services, and XML data transfer formats based on Automatic Test Markup Language (ATML). This open-source standards-based approach provides direct integration with existing commercial off-the-shelf (COTS) analysis software tools.

  10. The Use of End-to-End Multicast Measurements for Characterizing Internal Network Behavior

    DTIC Science & Technology

    2002-08-01

    dropping on the basis Random Early Detection ( RED ) [17] is another mechanism by which packet loss may become decorrelated. It remains to be seen whether...this mechanism will be widely deployed in communications networks. On the other hand, the use of RED to merely mark packets will not break correlations...Tail and Random Early Detection ( RED ) buffer discard methods, [17]. We compared the inferred loss and delay with actual probe loss and delay. We found

  11. Virtually-synchronous communication based on a weak failure suspector

    NASA Technical Reports Server (NTRS)

    Schiper, Andre; Ricciardi, Aleta

    1993-01-01

    Failure detectors (or, more accurately Failure Suspectors (FS)) appear to be a fundamental service upon which to build fault-tolerant, distributed applications. This paper shows that a FS with very weak semantics (i.e., that delivers failure and recovery information in no specific order) suffices to implement virtually-synchronous communication (VSC) in an asynchronous system subject to process crash failures and network partitions. The VSC paradigm is particularly useful in asynchronous systems and greatly simplifies building fault-tolerant applications that mask failures by replicating processes. We suggest a three-component architecture to implement virtually-synchronous communication: (1) at the lowest level, the FS component; (2) on top of it, a component (2a) that defines new views; and (3) a component (2b) that reliably multicasts messages within a view. The issues covered in this paper also lead to a better understanding of the various membership service semantics proposed in recent literature.

  12. Load balancing for massively-parallel soft-real-time systems

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

    Hailperin, M.

    1988-09-01

    Global load balancing, if practical, would allow the effective use of massively-parallel ensemble architectures for large soft-real-problems. The challenge is to replace quick global communications, which is impractical in a massively-parallel system, with statistical techniques. In this vein, the author proposes a novel approach to decentralized load balancing based on statistical time-series analysis. Each site estimates the system-wide average load using information about past loads of individual sites and attempts to equal that average. This estimation process is practical because the soft-real-time systems of interest naturally exhibit loads that are periodic, in a statistical sense akin to seasonality in econometrics.more » It is shown how this load-characterization technique can be the foundation for a load-balancing system in an architecture employing cut-through routing and an efficient multicast protocol.« less

  13. Efficient Assignment of Multiple E-MBMS Sessions towards LTE

    NASA Astrophysics Data System (ADS)

    Alexiou, Antonios; Bouras, Christos; Kokkinos, Vasileios

    One of the major prerequisites for Long Term Evolution (LTE) networks is the mass provision of multimedia services to mobile users. To this end, Evolved - Multimedia Broadcast/Multicast Service (E-MBMS) is envisaged to play an instrumental role during LTE standardization process and ensure LTE’s proliferation in mobile market. E-MBMS targets at the economic delivery, in terms of power and spectral efficiency, of multimedia data from a single source entity to multiple destinations. This paper proposes a novel mechanism for efficient radio bearer selection during E-MBMS transmissions in LTE networks. The proposed mechanism is based on the concept of transport channels combination in any cell of the network. Most significantly, the mechanism manages to efficiently deliver multiple E-MBMS sessions. The performance of the proposed mechanism is evaluated and compared with several radio bearer selection mechanisms in order to highlight the enhancements that it provides.

  14. 40 CFR 146.9 - Criteria for establishing permitting priorities.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ....9 Criteria for establishing permitting priorities. In determining priorities for setting times for... priorities. 146.9 Section 146.9 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER... (a), (c), (g) or § 144.22(f), the Director shall base these priorities upon consideration of the...

  15. A Real-Time Executive for Multiple-Computer Clusters.

    DTIC Science & Technology

    1984-12-01

    in a real-time environment is tantamount to speed and efficiency. By effectively co-locating real-time sensors and related processing modules, real...of which there are two ki n1 s : multicast group address - virtually any nur.,ber of node groups can be assigned a group address so they are all able...interfaceloopbark by 󈧅’b4, internal _loopback by 02"b4, clear loooback by 󈧇’b4, go offline by Ŝ"b4, eo online by 󈧍’b4, onboard _diagnostic by Oa’b4, cdr

  16. Can streamlined multi-criteria decision analysis be used to implement shared decision making for colorectal cancer screening?

    PubMed Central

    Dolan, James G.; Boohaker, Emily; Allison, Jeroan; Imperiale, Thomas F.

    2013-01-01

    Background Current US colorectal cancer screening guidelines that call for shared decision making regarding the choice among several recommended screening options are difficult to implement. Multi-criteria decision analysis (MCDA) is an established methodology well suited for supporting shared decision making. Our study goal was to determine if a streamlined form of MCDA using rank order based judgments can accurately assess patients’ colorectal cancer screening priorities. Methods We converted priorities for four decision criteria and three sub-criteria regarding colorectal cancer screening obtained from 484 average risk patients using the Analytic Hierarchy Process (AHP) in a prior study into rank order-based priorities using rank order centroids. We compared the two sets of priorities using Spearman rank correlation and non-parametric Bland-Altman limits of agreement analysis. We assessed the differential impact of using the rank order-based versus the AHP-based priorities on the results of a full MCDA comparing three currently recommended colorectal cancer screening strategies. Generalizability of the results was assessed using Monte Carlo simulation. Results Correlations between the two sets of priorities for the seven criteria ranged from 0.55 to 0.92. The proportions of absolute differences between rank order-based and AHP-based priorities that were more than ± 0.15 ranged from 1% to 16%. Differences in the full MCDA results were minimal and the relative rankings of the three screening options were identical more than 88% of the time. The Monte Carlo simulation results were similar. Conclusion Rank order-based MCDA could be a simple, practical way to guide individual decisions and assess population decision priorities regarding colorectal cancer screening strategies. Additional research is warranted to further explore the use of these methods for promoting shared decision making. PMID:24300851

  17. Flexible Unicast-Based Group Communication for CoAP-Enabled Devices †

    PubMed Central

    Ishaq, Isam; Hoebeke, Jeroen; Van den Abeele, Floris; Rossey, Jen; Moerman, Ingrid; Demeester, Piet

    2014-01-01

    Smart embedded objects will become an important part of what is called the Internet of Things. Applications often require concurrent interactions with several of these objects and their resources. Existing solutions have several limitations in terms of reliability, flexibility and manageability of such groups of objects. To overcome these limitations we propose an intermediately level of intelligence to easily manipulate a group of resources across multiple smart objects, building upon the Constrained Application Protocol (CoAP). We describe the design of our solution to create and manipulate a group of CoAP resources using a single client request. Furthermore we introduce the concept of profiles for the created groups. The use of profiles allows the client to specify in more detail how the group should behave. We have implemented our solution and demonstrate that it covers the complete group life-cycle, i.e., creation, validation, flexible usage and deletion. Finally, we quantitatively analyze the performance of our solution and compare it against multicast-based CoAP group communication. The results show that our solution improves reliability and flexibility with a trade-off in increased communication overhead. PMID:24901978

  18. Novel flat datacenter network architecture based on scalable and flow-controlled optical switch system.

    PubMed

    Miao, Wang; Luo, Jun; Di Lucente, Stefano; Dorren, Harm; Calabretta, Nicola

    2014-02-10

    We propose and demonstrate an optical flat datacenter network based on scalable optical switch system with optical flow control. Modular structure with distributed control results in port-count independent optical switch reconfiguration time. RF tone in-band labeling technique allowing parallel processing of the label bits ensures the low latency operation regardless of the switch port-count. Hardware flow control is conducted at optical level by re-using the label wavelength without occupying extra bandwidth, space, and network resources which further improves the performance of latency within a simple structure. Dynamic switching including multicasting operation is validated for a 4 x 4 system. Error free operation of 40 Gb/s data packets has been achieved with only 1 dB penalty. The system could handle an input load up to 0.5 providing a packet loss lower that 10(-5) and an average latency less that 500 ns when a buffer size of 16 packets is employed. Investigation on scalability also indicates that the proposed system could potentially scale up to large port count with limited power penalty.

  19. Secure distribution for high resolution remote sensing images

    NASA Astrophysics Data System (ADS)

    Liu, Jin; Sun, Jing; Xu, Zheng Q.

    2010-09-01

    The use of remote sensing images collected by space platforms is becoming more and more widespread. The increasing value of space data and its use in critical scenarios call for adoption of proper security measures to protect these data against unauthorized access and fraudulent use. In this paper, based on the characteristics of remote sensing image data and application requirements on secure distribution, a secure distribution method is proposed, including users and regions classification, hierarchical control and keys generation, and multi-level encryption based on regions. The combination of the three parts can make that the same remote sensing images after multi-level encryption processing are distributed to different permission users through multicast, but different permission users can obtain different degree information after decryption through their own decryption keys. It well meets user access control and security needs in the process of high resolution remote sensing image distribution. The experimental results prove the effectiveness of the proposed method which is suitable for practical use in the secure transmission of remote sensing images including confidential information over internet.

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

    PubMed

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

    2017-08-08

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

  1. Hybrid services efficient provisioning over the network coding-enabled elastic optical networks

    NASA Astrophysics Data System (ADS)

    Wang, Xin; Gu, Rentao; Ji, Yuefeng; Kavehrad, Mohsen

    2017-03-01

    As a variety of services have emerged, hybrid services have become more common in real optical networks. Although the elastic spectrum resource optimizations over the elastic optical networks (EONs) have been widely investigated, little research has been carried out on the hybrid services of the routing and spectrum allocation (RSA), especially over the network coding-enabled EON. We investigated the RSA for the unicast service and network coding-based multicast service over the network coding-enabled EON with the constraints of time delay and transmission distance. To address this issue, a mathematical model was built to minimize the total spectrum consumption for the hybrid services over the network coding-enabled EON under the constraints of time delay and transmission distance. The model guarantees different routing constraints for different types of services. The immediate nodes over the network coding-enabled EON are assumed to be capable of encoding the flows for different kinds of information. We proposed an efficient heuristic algorithm of the network coding-based adaptive routing and layered graph-based spectrum allocation algorithm (NCAR-LGSA). From the simulation results, NCAR-LGSA shows highly efficient performances in terms of the spectrum resources utilization under different network scenarios compared with the benchmark algorithms.

  2. Adaptive Peer Sampling with Newscast

    NASA Astrophysics Data System (ADS)

    Tölgyesi, Norbert; Jelasity, Márk

    The peer sampling service is a middleware service that provides random samples from a large decentralized network to support gossip-based applications such as multicast, data aggregation and overlay topology management. Lightweight gossip-based implementations of the peer sampling service have been shown to provide good quality random sampling while also being extremely robust to many failure scenarios, including node churn and catastrophic failure. We identify two problems with these approaches. The first problem is related to message drop failures: if a node experiences a higher-than-average message drop rate then the probability of sampling this node in the network will decrease. The second problem is that the application layer at different nodes might request random samples at very different rates which can result in very poor random sampling especially at nodes with high request rates. We propose solutions for both problems. We focus on Newscast, a robust implementation of the peer sampling service. Our solution is based on simple extensions of the protocol and an adaptive self-control mechanism for its parameters, namely—without involving failure detectors—nodes passively monitor local protocol events using them as feedback for a local control loop for self-tuning the protocol parameters. The proposed solution is evaluated by simulation experiments.

  3. The priority group index: a proposed new method incorporating high risk and population burden to identify target populations for public health interventions.

    PubMed

    Zhang, Bo; Cohen, Joanna E; OʼConnor, Shawn

    2014-01-01

    Selection of priority groups is important for health interventions. However, no quantitative method has been developed. To develop a quantitative method to support the process of selecting priority groups for public health interventions based on both high risk and population health burden. Secondary data analysis of the 2010 Canadian Community Health Survey. Canadian population. Survey respondents. We identified priority groups for 3 diseases: heart disease, stroke, and chronic lower respiratory diseases. Three measures--prevalence, population counts, and adjusted odds ratios (OR)--were calculated for subpopulations (sociodemographic characteristics and other risk factors). A Priority Group Index (PGI) was calculated by summing the rank scores of these 3 measures. Of the 30 priority groups identified by the PGI (10 for each of the 3 disease outcomes), 7 were identified on the basis of high prevalence only, 5 based on population count only, 3 based on high OR only, and the remainder based on combinations of these. The identified priority groups were all in line with the literature as risk factors for the 3 diseases, such as elderly people for heart disease and stroke and those with low income for chronic lower respiratory diseases. The PGI was thus able to balance both high risk and population burden approaches in selecting priority groups, and thus it would address health inequities as well as disease burden in the overall population. The PGI is a quantitative method to select priority groups for public health interventions; it has the potential to enhance the effective use of limited public resources.

  4. Selection and Evaluation of Priority Domains in Global Energy Internet Standard Development Based on Technology Foresight

    NASA Astrophysics Data System (ADS)

    Jin, Yang; Ciwei, Gao; Jing, Zhang; Min, Sun; Jie, Yu

    2017-05-01

    The selection and evaluation of priority domains in Global Energy Internet standard development will help to break through limits of national investment, thus priority will be given to standardizing technical areas with highest urgency and feasibility. Therefore, in this paper, the process of Delphi survey based on technology foresight is put forward, the evaluation index system of priority domains is established, and the index calculation method is determined. Afterwards, statistical method is used to evaluate the alternative domains. Finally the top four priority domains are determined as follows: Interconnected Network Planning and Simulation Analysis, Interconnected Network Safety Control and Protection, Intelligent Power Transmission and Transformation, and Internet of Things.

  5. Evaluation of concurrent priority queue algorithms. Technical report

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

    Huang, Q.

    1991-02-01

    The priority queue is a fundamental data structure that is used in a large variety of parallel algorithms, such as multiprocessor scheduling and parallel best-first search of state-space graphs. This thesis addresses the design and experimental evaluation of two novel concurrent priority queues: a parallel Fibonacci heap and a concurrent priority pool, and compares them with the concurrent binary heap. The parallel Fibonacci heap is based on the sequential Fibonacci heap, which is theoretically the most efficient data structure for sequential priority queues. This scheme not only preserves the efficient operation time bounds of its sequential counterpart, but also hasmore » very low contention by distributing locks over the entire data structure. The experimental results show its linearly scalable throughput and speedup up to as many processors as tested (currently 18). A concurrent access scheme for a doubly linked list is described as part of the implementation of the parallel Fibonacci heap. The concurrent priority pool is based on the concurrent B-tree and the concurrent pool. The concurrent priority pool has the highest throughput among the priority queues studied. Like the parallel Fibonacci heap, the concurrent priority pool scales linearly up to as many processors as tested. The priority queues are evaluated in terms of throughput and speedup. Some applications of concurrent priority queues such as the vertex cover problem and the single source shortest path problem are tested.« less

  6. High-priority and low-priority drug-drug interactions in different international electronic health record systems: A comparative study.

    PubMed

    Cornu, Pieter; Phansalkar, Shobha; Seger, Diane L; Cho, Insook; Pontefract, Sarah; Robertson, Alexandra; Bates, David W; Slight, Sarah P

    2018-03-01

    To investigate whether alert warnings for high-priority and low-priority drug-drug interactions (DDIs) were present in five international electronic health record (EHR) systems, to compare and contrast the severity level assigned to them, and to establish the proportion of alerts that were overridden. We conducted a comparative, retrospective, multinational study using a convenience sample of 5 EHRs from the U.S., U.K., Republic of Korea and Belgium. Of the 15 previously defined, high-priority, class-based DDIs, alert warnings were found to exist for 11 in both the Korean and UK systems, 9 in the Belgian system, and all 15 in the two US systems. The specific combinations that were included in these class-based DDIs varied considerably in number, type and level of severity amongst systems. Alerts were only active for 8.4% (52/619) and 52.4% (111/212) of the specific drug-drug combinations contained in the Belgian and UK systems, respectively. Hard stops (not possible to override) existed in the US and UK systems only. The override rates for high-priority alerts requiring provider action ranged from 56.7% to 83.3%. Of the 33 previously defined low-priority DDIs, active alerts existed only in the US systems, for three class-based DDIs. The majority were non-interruptive. Alert warnings existed for most of the high-priority DDIs in the different EHRs but overriding them was easy in most of the systems. In addition to validating the high- and low-priority DDIs, this study reported a lack of standardization in DDI levels across different international knowledge bases. Copyright © 2017. Published by Elsevier B.V.

  7. 15 CFR 700.20 - Use of priority ratings.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...) BUREAU OF INDUSTRY AND SECURITY, DEPARTMENT OF COMMERCE NATIONAL SECURITY INDUSTRIAL BASE REGULATIONS DEFENSE PRIORITIES AND ALLOCATIONS SYSTEM Industrial Priorities for Energy Programs § 700.20 Use of... maintenance of energy facilities. ...

  8. 15 CFR 700.16 - Changes or cancellations of priority ratings and rated orders.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Commerce and Foreign Trade (Continued) BUREAU OF INDUSTRY AND SECURITY, DEPARTMENT OF COMMERCE NATIONAL SECURITY INDUSTRIAL BASE REGULATIONS DEFENSE PRIORITIES AND ALLOCATIONS SYSTEM Industrial Priorities § 700...

  9. A group communication approach for mobile computing mobile channel: An ISIS tool for mobile services

    NASA Astrophysics Data System (ADS)

    Cho, Kenjiro; Birman, Kenneth P.

    1994-05-01

    This paper examines group communication as an infrastructure to support mobility of users, and presents a simple scheme to support user mobility by means of switching a control point between replicated servers. We describe the design and implementation of a set of tools, called Mobile Channel, for use with the ISIS system. Mobile Channel is based on a combination of the two replication schemes: the primary-backup approach and the state machine approach. Mobile Channel implements a reliable one-to-many FIFO channel, in which a mobile client sees a single reliable server; servers, acting as a state machine, see multicast messages from clients. Migrations of mobile clients are handled as an intentional primary switch, and hand-offs or server failures are completely masked to mobile clients. To achieve high performance, servers are replicated at a sliding-window level. Our scheme provides a simple abstraction of migration, eliminates complicated hand-off protocols, provides fault-tolerance and is implemented within the existing group communication mechanism.

  10. TeCo3D: a 3D telecooperation application based on VRML and Java

    NASA Astrophysics Data System (ADS)

    Mauve, Martin

    1998-12-01

    In this paper we present a method for sharing collaboration- unaware VRML content, e.g. 3D models which were not specifically developed for use in a distributed environment. This functionality is an essential requirement for the inclusion of arbitrary VRML content, as generated by standard CAD or animation software, into teleconferencing sessions. We have developed a 3D TeleCooperation (TeCo3D) prototype to demonstrate the feasibility of our approach. The basic services provided by the prototype are the distribution of cooperation unaware VRML content, the sharing of user interactions, and the joint viewing of the content. In order to achieve maximum portability, the prototype was developed completely in Java. This paper presents general aspects of sharing VRML content as well as the concepts, the architecture and the services of the TeCo3D prototype. Our approach relies on existing VRML browsers as the VRML presentation and execution engines while reliable multicast is used as the means of communication to provide for scalability.

  11. A Performance Evaluation of NACK-Oriented Protocols as the Foundation of Reliable Delay- Tolerant Networking Convergence Layers

    NASA Technical Reports Server (NTRS)

    Iannicca, Dennis; Hylton, Alan; Ishac, Joseph

    2012-01-01

    Delay-Tolerant Networking (DTN) is an active area of research in the space communications community. DTN uses a standard layered approach with the Bundle Protocol operating on top of transport layer protocols known as convergence layers that actually transmit the data between nodes. Several different common transport layer protocols have been implemented as convergence layers in DTN implementations including User Datagram Protocol (UDP), Transmission Control Protocol (TCP), and Licklider Transmission Protocol (LTP). The purpose of this paper is to evaluate several stand-alone implementations of negative-acknowledgment based transport layer protocols to determine how they perform in a variety of different link conditions. The transport protocols chosen for this evaluation include Consultative Committee for Space Data Systems (CCSDS) File Delivery Protocol (CFDP), Licklider Transmission Protocol (LTP), NACK-Oriented Reliable Multicast (NORM), and Saratoga. The test parameters that the protocols were subjected to are characteristic of common communications links ranging from terrestrial to cis-lunar and apply different levels of delay, line rate, and error.

  12. Development and Technical Validation of the Mobile Based Assistive Listening System: A Smartphone-Based Remote Microphone.

    PubMed

    Lopez, Esteban Alejandro; Costa, Orozimbo Alves; Ferrari, Deborah Viviane

    2016-10-01

    The purpose of this research note is to describe the development and technical validation of the Mobile Based Assistive Listening System (MoBALS), a free-of-charge smartphone-based remote microphone application. MoBALS Version 1.0 was developed for Android (Version 2.1 or higher) and was coded with Java using Eclipse Indigo with the Android Software Development Kit. A Wi-Fi router with background traffic and 2 affordable smartphones were used for debugging and technical validation comprising, among other things, multicasting capability, data packet loss, and battery consumption. MoBALS requires at least 2 smartphones connected to the same Wi-Fi router for signal transmission and reception. Subscriber identity module cards or Internet connections are not needed. MoBALS can be used alone or connected to a hearing aid or cochlear implant via direct audio input. Maximum data packet loss was 99.28%, and minimum battery life was 5 hr. Other relevant design specifications and their implementation are described. MoBALS performed as a remote microphone with enhanced accessibility features and avoids overhead expenses by using already-available and affordable technology. The further development and technical revalidation of MoBALS will be followed by clinical evaluation with persons with hearing impairment.

  13. Internetworking satellite and local exchange networks for personal communications applications

    NASA Technical Reports Server (NTRS)

    Wolff, Richard S.; Pinck, Deborah

    1993-01-01

    The demand for personal communications services has shown unprecedented growth, and the next decade and beyond promise an era in which the needs for ubiquitous, transparent and personalized access to information will continue to expand in both scale and scope. The exchange of personalized information is growing from two-way voice to include data communications, electronic messaging and information services, image transfer, video, and interactive multimedia. The emergence of new land-based and satellite-based wireless networks illustrates the expanding scale and trend toward globalization and the need to establish new local exchange and exchange access services to meet the communications needs of people on the move. An important issue is to identify the roles that satellite networking can play in meeting these new communications needs. The unique capabilities of satellites, in providing coverage to large geographic areas, reaching widely dispersed users, for position location determination, and in offering broadcast and multicast services, can complement and extend the capabilities of terrestrial networks. As an initial step in exploring the opportunities afforded by the merger of satellite-based and land-based networks, several experiments utilizing the NASA ACTS satellite and the public switched local exchange network were undertaken to demonstrate the use of satellites in the delivery of personal communications services.

  14. Automation Hooks Architecture for Flexible Test Orchestration - Concept Development and Validation

    NASA Technical Reports Server (NTRS)

    Lansdowne, C. A.; Maclean, John R.; Winton, Chris; McCartney, Pat

    2011-01-01

    The Automation Hooks Architecture Trade Study for Flexible Test Orchestration sought a standardized data-driven alternative to conventional automated test programming interfaces. The study recommended composing the interface using multicast DNS (mDNS/SD) service discovery, Representational State Transfer (Restful) Web Services, and Automatic Test Markup Language (ATML). We describe additional efforts to rapidly mature the Automation Hooks Architecture candidate interface definition by validating it in a broad spectrum of applications. These activities have allowed us to further refine our concepts and provide observations directed toward objectives of economy, scalability, versatility, performance, severability, maintainability, scriptability and others.

  15. Integrating security in a group oriented distributed system

    NASA Technical Reports Server (NTRS)

    Reiter, Michael; Birman, Kenneth; Gong, LI

    1992-01-01

    A distributed security architecture is proposed for incorporation into group oriented distributed systems, and in particular, into the Isis distributed programming toolkit. The primary goal of the architecture is to make common group oriented abstractions robust in hostile settings, in order to facilitate the construction of high performance distributed applications that can tolerate both component failures and malicious attacks. These abstractions include process groups and causal group multicast. Moreover, a delegation and access control scheme is proposed for use in group oriented systems. The focus is the security architecture; particular cryptosystems and key exchange protocols are not emphasized.

  16. Research priorities in medical education at Shiraz University of Medical Sciences:categories and subcategories in the Iranian context

    PubMed Central

    NABEIEI, PARISA; AMINI, MITRA; GHANAVATI, SHIRIN; MARHAMATI, SAADAT

    2016-01-01

    Introduction Research in education is a globally significant issue without a long history. Due to the importance of the issue in Health System Development programs, this study intended to determine research priorities in medical education, considering their details and functions. By determining barriers existing in research in education progress, it is tried to make research priorities more functional by recommending acceptable strategies. Methods This is a qualitative-descriptive study in two descriptive phases. The goal of these phases was to determine research priorities subcategories in medical education by Nominal Group Technique (NGT) and two rounds of Delphi method. Through the first phase, subcategories of research priorities were determined, using Nominal Group Technique under medical education experts’ supervision. Through two rounds of Delphi, a questionnaire was constructed based on the subcategories. Eventually, research priorities were determined based on their highest score (scores more than 7 out of 10). Results In the first phase (NGT), 35 priorities in 5 major fields of medical education were presented. In the second phase, priorities were scored, using Delphi method. Medical Ethics and professionalism gained the highest scores (7.63±1.26) and educational evaluation the lowest (7.28±1.52). In this stage, 7 items were omitted but 2 of them were added again after experts’ revision in the third round of Delphi. Conclusion According to the results of the present study and based on previous studies, it really seems that the fields of “Learning and Teaching Approaches” and “Medical Ethics and Professionalism” were more important. Because of financial and resource limitations in our country and the importance of research priorities, it is recommended to frequently study “research priorities determination program” at universities. PMID:26793723

  17. Priorities in health care: reply to Lewis and Charny.

    PubMed Central

    Lamb, David

    1989-01-01

    This paper is a reply to proposals to base priority health-care decisions on public opinion surveys. Whilst it is recognised that current practice is less than satisfactory, it is argued here that basing health-care priorities on societal attitudes in this way is not a solution and does not provide a satisfactory basis for bringing democracy to the health service. PMID:11644371

  18. Differences between Parkinson's and Huntington's diseases and their role for prioritization of stem cell-based treatments.

    PubMed

    Hug, K; Hermerén, G

    2013-06-01

    The problems of allocation of scarce resources and priority setting in health care have so far not been much studied in the context of stem cell-based therapeutic applications. If and when competitive cost effective stem cell-based therapies are available, the problem of priority setting - to whom should stem cellbased therapies be offered and on what grounds - is discussed in this article using the examples of Parkinson's Disease (PD) and Huntington's Disease (HD). The aim of this paper is to examine the presently known differences between PD and HD and analyze the role of these differences for setting priorities of stem cell-based therapeutic applications to treat these diseases. To achieve this aim, we (1) present the theoretical framework used in the analysis; (2) compare PD and HD in terms of health related and non-health related consequences of these diseases for patients, their relatives and third parties; (3) analyze the ethical relevance of observed differences for priority setting given different values and variables; (4) compare PD and HD in terms of social justice related consequences of stem cell-based therapies; and (5) analyze the ethical relevance of these differences for priority setting given different values and variables. We argue that the steps of analysis applied in this paper could be helpful when setting priorities among treatments of other diseases with similar differences as those between PD and HD.

  19. Toward a comprehensive strategy for effective practitioner-scientist partnerships and larger-scale community health and well-being.

    PubMed

    Spoth, Richard L; Greenberg, Mark T

    2005-06-01

    This article articulates joint priorities for the fields of prevention science and community psychology. These priorities are intended to address issues raised by the frequent observation of natural tensions between community practitioners and scientists. The first priority is to expand the knowledge base on practitioner-scientist partnerships, particularly on factors associated with positive outcomes within communities. To further articulate this priority, the paper first discusses the rapid growth in community-based partnerships and the emergent research on them. Next described is an illustrative research project on a partnership model that links state university extension and public school delivery systems. The article then turns to the second, related priority of future capacity-building for diffusion of effective partnership-based interventions to achieve larger-scale health and well-being across communities. It outlines two salient tasks: clarification of a conceptual framework and the formulation of a comprehensive capacity-building strategy for diffusion. The comprehensive strategy would require careful attention to the expansion of networks of effective partnerships, partnership-based research agendas, and requisite policy-making.

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

    PubMed Central

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

    2017-01-01

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

  1. A Lightweight Protocol for Secure Video Streaming

    PubMed Central

    Morkevicius, Nerijus; Bagdonas, Kazimieras

    2018-01-01

    The Internet of Things (IoT) introduces many new challenges which cannot be solved using traditional cloud and host computing models. A new architecture known as fog computing is emerging to address these technological and security gaps. Traditional security paradigms focused on providing perimeter-based protections and client/server point to point protocols (e.g., Transport Layer Security (TLS)) are no longer the best choices for addressing new security challenges in fog computing end devices, where energy and computational resources are limited. In this paper, we present a lightweight secure streaming protocol for the fog computing “Fog Node-End Device” layer. This protocol is lightweight, connectionless, supports broadcast and multicast operations, and is able to provide data source authentication, data integrity, and confidentiality. The protocol is based on simple and energy efficient cryptographic methods, such as Hash Message Authentication Codes (HMAC) and symmetrical ciphers, and uses modified User Datagram Protocol (UDP) packets to embed authentication data into streaming data. Data redundancy could be added to improve reliability in lossy networks. The experimental results summarized in this paper confirm that the proposed method efficiently uses energy and computational resources and at the same time provides security properties on par with the Datagram TLS (DTLS) standard. PMID:29757988

  2. A Lightweight Protocol for Secure Video Streaming.

    PubMed

    Venčkauskas, Algimantas; Morkevicius, Nerijus; Bagdonas, Kazimieras; Damaševičius, Robertas; Maskeliūnas, Rytis

    2018-05-14

    The Internet of Things (IoT) introduces many new challenges which cannot be solved using traditional cloud and host computing models. A new architecture known as fog computing is emerging to address these technological and security gaps. Traditional security paradigms focused on providing perimeter-based protections and client/server point to point protocols (e.g., Transport Layer Security (TLS)) are no longer the best choices for addressing new security challenges in fog computing end devices, where energy and computational resources are limited. In this paper, we present a lightweight secure streaming protocol for the fog computing "Fog Node-End Device" layer. This protocol is lightweight, connectionless, supports broadcast and multicast operations, and is able to provide data source authentication, data integrity, and confidentiality. The protocol is based on simple and energy efficient cryptographic methods, such as Hash Message Authentication Codes (HMAC) and symmetrical ciphers, and uses modified User Datagram Protocol (UDP) packets to embed authentication data into streaming data. Data redundancy could be added to improve reliability in lossy networks. The experimental results summarized in this paper confirm that the proposed method efficiently uses energy and computational resources and at the same time provides security properties on par with the Datagram TLS (DTLS) standard.

  3. Bottom-up priority setting revised. A second evaluation of an institutional intervention in a Swedish health care organisation.

    PubMed

    Waldau, Susanne

    2015-09-01

    Transparent priority setting in health care based on specific ethical principles is requested by the Swedish Parliament since 1997. Implementation has been limited. In this case, transparent priority setting was performed for a second time round and engaged an entire health care organisation. Objectives were to refine a bottom-up priority setting process, reach a political decision on service limits to make reallocation towards higher prioritised services possible, and raise systems knowledge. An action research approach was chosen. The national model for priority setting was used with addition of dimensions costs, volumes, gender distribution and feasibility. The intervention included a three step process and specific procedures for each step which were created, revised and evaluated regarding factual and functional aspects. Evaluations methods included analyses of documents, recordings and surveys. Vertical and horizontal priority setting occurred and resources were reallocated. Participants' attitudes remained positive, however less so than in the first priority setting round. Identifying low-priority services was perceived difficult, causing resentment and strategic behaviour. The horizontal stage served to raise quality of the knowledge base, level out differences in ranking of services and raise systems knowledge. Existing health care management systems do not meet institutional requirements for transparent priority setting. Introducing transparent priority setting constitutes a complex institutional reform, which needs to be driven by management/administration. Strong managerial commitment is required. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  4. Cheating and Anti-Cheating in Gossip-Based Protocol: An Experimental Investigation

    NASA Astrophysics Data System (ADS)

    Xiao, Xin; Shi, Yuanchun; Tang, Yun; Zhang, Nan

    During recent years, there has been a rapid growth in deployment of gossip-based protocol in many multicast applications. In a typical gossip-based protocol, each node acts as dual roles of receiver and sender, independently exchanging data with its neighbors to facilitate scalability and resilience. However, most of previous work in this literature seldom considered cheating issue of end users, which is also very important in face of the fact that the mutual cooperation inherently determines overall system performance. In this paper, we investigate the dishonest behaviors in decentralized gossip-based protocol through extensive experimental study. Our original contributions come in two-fold: In the first part of cheating study, we analytically discuss two typical cheating strategies, that is, intentionally increasing subscription requests and untruthfully calculating forwarding probability, and further evaluate their negative impacts. The results indicate that more attention should be paid to defending cheating behaviors in gossip-based protocol. In the second part of anti-cheating study, we propose a receiver-driven measurement mechanism, which evaluates individual forwarding traffic from the perspective of receivers and thus identifies cheating nodes with high incoming/outgoing ratio. Furthermore, we extend our mechanism by introducing reliable factor to further improve its accuracy. The experiments under various conditions show that it performs quite well in case of serious cheating and achieves considerable performance in other cases.

  5. P2MP MPLS-Based Hierarchical Service Management System

    NASA Astrophysics Data System (ADS)

    Kumaki, Kenji; Nakagawa, Ikuo; Nagami, Kenichi; Ogishi, Tomohiko; Ano, Shigehiro

    This paper proposes a point-to-multipoint (P2MP) Multi-Protocol Label Switching (MPLS) based hierarchical service management system. Traditionally, general management systems deployed in some service providers control MPLS Label Switched Paths (LSPs) (e.g., RSVP-TE and LDP) and services (e.g., L2VPN, L3VPN and IP) separately. In order for dedicated management systems for MPLS LSPs and services to cooperate with each other automatically, a hierarchical service management system has been proposed with the main focus on point-to-point (P2P) TE LSPs in MPLS path management. In the case where P2MP TE LSPs and services are deployed in MPLS networks, the dedicated management systems for P2MP TE LSPs and services must work together automatically. Therefore, this paper proposes a new algorithm that uses a correlation between P2MP TE LSPs and multicast VPN services based on a P2MP MPLS-based hierarchical service management architecture. Also, the capacity and performance of the proposed algorithm are evaluated by simulations, which are actually based on certain real MPLS production networks, and are compared to that of the algorithm for P2P TE LSPs. Results show this system is very scalable within real MPLS production networks. This system, with the automatic correlation, appears to be deployable in real MPLS production networks.

  6. Prioritising in situ conservation of crop resources: A case study of African cowpea (Vigna unguiculata)

    PubMed Central

    Moray, C.; Game, E. T.; Maxted, N.

    2014-01-01

    Conserving crop wild relatives (CWR) is critical for maintaining food security. However, CWR-focused conservation plans are lacking, and are often based on the entire genus, even though only a few taxa are useful for crop improvement. We used taxonomic and geographic prioritisation to identify the best locations for in situ conservation of the most important (priority) CWR, using African cowpea (Vigna unguiculata (L.) Walp.) as a case study. Cowpea is an important crop for subsistence farmers in sub-Saharan Africa, yet its CWR are under-collected, under-conserved and under-utilised in breeding. We identified the most efficient sites to focus in situ cowpea CWR conservation and assessed whether priority CWR would be adequately represented in a genus-based conservation plan. We also investigated whether priority cowpea CWR are likely to be found in existing conservation areas and in areas important for mammal conservation. The genus-based method captured most priority CWR, and the distributions of many priority CWR overlapped with established conservation reserves and targets. These results suggest that priority cowpea CWR can be conserved by building on conservation initiatives established for other species. PMID:24936740

  7. Prioritising in situ conservation of crop resources: a case study of African cowpea (Vigna unguiculata).

    PubMed

    Moray, C; Game, E T; Maxted, N

    2014-06-17

    Conserving crop wild relatives (CWR) is critical for maintaining food security. However, CWR-focused conservation plans are lacking, and are often based on the entire genus, even though only a few taxa are useful for crop improvement. We used taxonomic and geographic prioritisation to identify the best locations for in situ conservation of the most important (priority) CWR, using African cowpea (Vigna unguiculata (L.) Walp.) as a case study. Cowpea is an important crop for subsistence farmers in sub-Saharan Africa, yet its CWR are under-collected, under-conserved and under-utilised in breeding. We identified the most efficient sites to focus in situ cowpea CWR conservation and assessed whether priority CWR would be adequately represented in a genus-based conservation plan. We also investigated whether priority cowpea CWR are likely to be found in existing conservation areas and in areas important for mammal conservation. The genus-based method captured most priority CWR, and the distributions of many priority CWR overlapped with established conservation reserves and targets. These results suggest that priority cowpea CWR can be conserved by building on conservation initiatives established for other species.

  8. Who Shall Not Be Treated: Public Attitudes on Setting Health Care Priorities by Person-Based Criteria in 28 Nations.

    PubMed

    Rogge, Jana; Kittel, Bernhard

    2016-01-01

    The principle of distributing health care according to medical need is being challenged by increasing costs. As a result, many countries have initiated a debate on the introduction of explicit priority regulations based on medical, economic and person-based criteria, or have already established such regulations. Previous research on individual attitudes towards setting health care priorities based on medical and economic criteria has revealed consistent results, whereas studies on the use of person-based criteria have generated controversial findings. This paper examines citizens' attitudes towards three person-based priority criteria, patients' smoking habits, age and being the parent of a young child. Using data from the ISSP Health Module (2011) in 28 countries, logistic regression analysis demonstrates that self-interest as well as socio-demographic predictors significantly influence respondents' attitudes towards the use of person-based criteria for health care prioritization. This study contributes to resolving the controversial findings on person-based criteria by using a larger country sample and by controlling for country-level differences with fixed effects models.

  9. Exemplar-Based Image Inpainting Using a Modified Priority Definition.

    PubMed

    Deng, Liang-Jian; Huang, Ting-Zhu; Zhao, Xi-Le

    2015-01-01

    Exemplar-based algorithms are a popular technique for image inpainting. They mainly have two important phases: deciding the filling-in order and selecting good exemplars. Traditional exemplar-based algorithms are to search suitable patches from source regions to fill in the missing parts, but they have to face a problem: improper selection of exemplars. To improve the problem, we introduce an independent strategy through investigating the process of patches propagation in this paper. We first define a new separated priority definition to propagate geometry and then synthesize image textures, aiming to well recover image geometry and textures. In addition, an automatic algorithm is designed to estimate steps for the new separated priority definition. Comparing with some competitive approaches, the new priority definition can recover image geometry and textures well.

  10. Exemplar-Based Image Inpainting Using a Modified Priority Definition

    PubMed Central

    Deng, Liang-Jian; Huang, Ting-Zhu; Zhao, Xi-Le

    2015-01-01

    Exemplar-based algorithms are a popular technique for image inpainting. They mainly have two important phases: deciding the filling-in order and selecting good exemplars. Traditional exemplar-based algorithms are to search suitable patches from source regions to fill in the missing parts, but they have to face a problem: improper selection of exemplars. To improve the problem, we introduce an independent strategy through investigating the process of patches propagation in this paper. We first define a new separated priority definition to propagate geometry and then synthesize image textures, aiming to well recover image geometry and textures. In addition, an automatic algorithm is designed to estimate steps for the new separated priority definition. Comparing with some competitive approaches, the new priority definition can recover image geometry and textures well. PMID:26492491

  11. 7 CFR 4279.155 - Loan priorities.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... natural disaster or experiencing fundamental structural changes in its economic base (5 points). (iv... the maximum allowable for a loan of its size (5 points). (5) High impact business investment priorities. The priority score for high impact business investment will be the total score for the following...

  12. An approach for setting evidence-based and stakeholder-informed research priorities in low- and middle-income countries.

    PubMed

    Rehfuess, Eva A; Durão, Solange; Kyamanywa, Patrick; Meerpohl, Joerg J; Young, Taryn; Rohwer, Anke

    2016-04-01

    To derive evidence-based and stakeholder-informed research priorities for implementation in African settings, the international research consortium Collaboration for Evidence-Based Healthcare and Public Health in Africa (CEBHA+) developed and applied a pragmatic approach. First, an online survey and face-to-face consultation between CEBHA+ partners and policy-makers generated priority research areas. Second, evidence maps for these priority research areas identified gaps and related priority research questions. Finally, study protocols were developed for inclusion within a grant proposal. Policy and practice representatives were involved throughout the process. Tuberculosis, diabetes, hypertension and road traffic injuries were selected as priority research areas. Evidence maps covered screening and models of care for diabetes and hypertension, population-level prevention of diabetes and hypertension and their risk factors, and prevention and management of road traffic injuries. Analysis of these maps yielded three priority research questions on hypertension and diabetes and one on road traffic injuries. The four resulting study protocols employ a broad range of primary and secondary research methods; a fifth promotes an integrated methodological approach across all research activities. The CEBHA+ approach, in particular evidence mapping, helped to formulate research questions and study protocols that would be owned by African partners, fill gaps in the evidence base, address policy and practice needs and be feasible given the existing research infrastructure and expertise. The consortium believes that the continuous involvement of decision-makers throughout the research process is an important means of ensuring that studies are relevant to the African context and that findings are rapidly implemented.

  13. Expert Design Advisor

    DTIC Science & Technology

    1990-10-01

    to economic, technological, spatial or logistic concerns, or involve training, man-machine interfaces, or integration into existing systems. Once the...probabilistic reasoning, mixed analysis- and simulation-oriented, mixed computation- and communication-oriented, nonpreemptive static priority...scheduling base, nonrandomized, preemptive static priority scheduling base, randomized, simulation-oriented, and static scheduling base. The selection of both

  14. Strategic Issues: Priorities for the Future.

    ERIC Educational Resources Information Center

    Alamo Community Coll. District, San Antonio, TX.

    Strategic priorities for the Alamo Community College District (ACCD) are identified based on conclusions drawn by the ACCD Community Advisory Council from studies of: (1) Bexar County population characteristics and trends; (2) community economic and social priorities; (3) college enrollment potential; (4) needs and characteristics of the ACCD's…

  15. Two-dimensional priority-based dynamic resource allocation algorithm for QoS in WDM/TDM PON networks

    NASA Astrophysics Data System (ADS)

    Sun, Yixin; Liu, Bo; Zhang, Lijia; Xin, Xiangjun; Zhang, Qi; Rao, Lan

    2018-01-01

    Wavelength division multiplexing/time division multiplexing (WDM/TDM) passive optical networks (PON) is being viewed as a promising solution for delivering multiple services and applications. The hybrid WDM / TDM PON uses the wavelength and bandwidth allocation strategy to control the distribution of the wavelength channels in the uplink direction, so that it can ensure the high bandwidth requirements of multiple Optical Network Units (ONUs) while improving the wavelength resource utilization. Through the investigation of the presented dynamic bandwidth allocation algorithms, these algorithms can't satisfy the requirements of different levels of service very well while adapting to the structural characteristics of mixed WDM / TDM PON system. This paper introduces a novel wavelength and bandwidth allocation algorithm to efficiently utilize the bandwidth and support QoS (Quality of Service) guarantees in WDM/TDM PON. Two priority based polling subcycles are introduced in order to increase system efficiency and improve system performance. The fixed priority polling subcycle and dynamic priority polling subcycle follow different principles to implement wavelength and bandwidth allocation according to the priority of different levels of service. A simulation was conducted to study the performance of the priority based polling in dynamic resource allocation algorithm in WDM/TDM PON. The results show that the performance of delay-sensitive services is greatly improved without degrading QoS guarantees for other services. Compared with the traditional dynamic bandwidth allocation algorithms, this algorithm can meet bandwidth needs of different priority traffic class, achieve low loss rate performance, and ensure real-time of high priority traffic class in terms of overall traffic on the network.

  16. Impact Analysis of Flow Shaping in Ethernet-AVB/TSN and AFDX from Network Calculus and Simulation Perspective

    PubMed Central

    He, Feng; Zhao, Lin; Li, Ershuai

    2017-01-01

    Ethernet-AVB/TSN (Audio Video Bridging/Time-Sensitive Networking) and AFDX (Avionics Full DupleX switched Ethernet) are switched Ethernet technologies, which are both candidates for real-time communication in the context of transportation systems. AFDX implements a fixed priority scheduling strategy with two priority levels. Ethernet-AVB/TSN supports a similar fixed priority scheduling with an additional Credit-Based Shaper (CBS) mechanism. Besides, TSN can support time-triggered scheduling strategy. One direct effect of CBS mechanism is to increase the delay of its flows while decreasing the delay of other priority ones. The former effect can be seen as the shaping restriction and the latter effect can be seen as the shaping benefit from CBS. The goal of this paper is to investigate the impact of CBS on different priority flows, especially on the intermediate priority ones, as well as the effect of CBS bandwidth allocation. It is based on a performance comparison of AVB/TSN and AFDX by simulation in an automotive case study. Furthermore, the shaping benefit is modeled based on integral operation from network calculus perspective. Combing with the analysis of shaping restriction and shaping benefit, some configuration suggestions on the setting of CBS bandwidth are given. Results show that the effect of CBS depends on flow loads and CBS configurations. A larger load of high priority flows in AVB tends to a better performance for the intermediate priority flows when compared with AFDX. Shaping benefit can be explained and calculated according to the changing from the permitted maximum burst. PMID:28531158

  17. Data Analyses and Modelling for Risk Based Monitoring of Mycotoxins in Animal Feed

    PubMed Central

    van der Fels-Klerx, H.J. (Ine); Adamse, Paulien; Punt, Ans; van Asselt, Esther D.

    2018-01-01

    Following legislation, European Member States should have multi-annual control programs for contaminants, such as for mycotoxins, in feed and food. These programs need to be risk based implying the checks are regular and proportional to the estimated risk for animal and human health. This study aimed to prioritize feed products in the Netherlands for deoxynivalenol and aflatoxin B1 monitoring. Historical mycotoxin monitoring results from the period 2007–2016 were combined with data from other sources. Based on occurrence, groundnuts had high priority for aflatoxin B1 monitoring; some feed materials (maize and maize products and several oil seed products) and complete/complementary feed excluding dairy cattle and young animals had medium priority; and all other animal feeds and feed materials had low priority. For deoxynivalenol, maize by-products had a high priority, complete and complementary feed for pigs had a medium priority and all other feed and feed materials a low priority. Also including health consequence estimations showed that feed materials that ranked highest for aflatoxin B1 included sunflower seed and palmkernel expeller/extracts and maize. For deoxynivalenol, maize products were ranked highest, followed by various small grain cereals (products); all other feed materials were of lower concern. Results of this study have proven to be useful in setting up the annual risk based control program for mycotoxins in animal feed and feed materials. PMID:29373559

  18. Method and apparatus for granting processors access to a resource

    DOEpatents

    Blumrich, Matthias A.; Salapura, Valentina

    2010-03-16

    An apparatus and method for granting one or more requesting entities access to a resource in a predetermined time interval. The apparatus includes a first circuit receiving one or more request signals, and implementing logic for assigning a priority to the one or more request signals, and, generating a set of first_request signals based on the priorities assigned. One or more priority select circuits for receiving the set of first_request signals and generating corresponding one or more fixed grant signals representing one or more highest priority request signals when asserted during the predetermined time interval. A second circuit device receives the one or more fixed grant signals generates one or more grant signals associated with one or more highest priority request signals assigned, the grant signals for enabling one or more respective requesting entities access to the resource in the predetermined time interval, wherein the priority assigned to the one or more request signals changes each successive predetermined time interval. In one embodiment, the assigned priority is based on a numerical pattern, the first circuit changing the numerical pattern with respect to the first_request signals generated at each successive predetermined time interval.

  19. Priority setting in the provincial health services authority: survey of key decision makers

    PubMed Central

    Teng, Flora; Mitton, Craig; MacKenzie, Jennifer

    2007-01-01

    Background In recent years, decision makers in Canada and elsewhere have expressed a desire for more explicit, evidence-based approaches to priority setting. To achieve this aim within health care organizations, knowledge of both the organizational context and stakeholder attitudes towards priority setting are required. The current work adds to a limited yet growing body of international literature describing priority setting practices in health organizations. Methods A qualitative study was conducted using in-depth, face-to-face interviews with 25 key decision makers of the Provincial Health Services Authority (PHSA) of British Columbia. Major themes and sub-themes were identified through content analysis. Results Priorities were described by decision makers as being set in an ad hoc manner, with resources generally allocated along historical lines. Participants identified the Strategic Plan and a strong research base as strengths of the organization. The main areas for improvement were a desire to have a more transparent process for priority setting, a need to develop a culture which supports explicit priority setting, and a focus on fairness in decision making. Barriers to an explicit allocation process included the challenge of providing specialized services for disparate patient groups, and a lack of formal training in priority setting amongst decision makers. Conclusion This study identified factors important to understanding organizational context and informed next steps for explicit priority setting for a provincial health authority. While the PHSA is unique in its organizational structure in Canada, lessons about priority setting should be transferable to other contexts. PMID:17565691

  20. 12 CFR 1806.203 - Selection Process, actual award amounts.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Community Financing Activities, ranked in the order set forth in the applicable NOFA. (3) Third Priority. If... amounts based on the process described in this section. (c) Priority of Awards. The Fund will rank Applicants in each category of Qualified Activity according to the priorities described in this paragraph (c...

  1. Reward-based plasticity of spatial priority maps: Exploiting inter-subject variability to probe the underlying neurobiology.

    PubMed

    Della Libera, Chiara; Calletti, Riccardo; Eštočinová, Jana; Chelazzi, Leonardo; Santandrea, Elisa

    2017-04-01

    Recent evidence indicates that the attentional priority of objects and locations is altered by the controlled delivery of reward, reflecting reward-based attentional learning. Here, we take an approach hinging on intersubject variability to probe the neurobiological bases of the reward-driven plasticity of spatial priority maps. Specifically, we ask whether an individual's susceptibility to the reward-based treatment can be accounted for by specific predictors, notably personality traits that are linked to reward processing (along with more general personality traits), but also gender. Using a visual search protocol, we show that when different target locations are associated with unequal reward probability, different priorities are acquired by the more rewarded relative to the less rewarded locations. However, while males exhibit the expected pattern of results, with greater priority for locations associated with higher reward, females show an opposite trend. Critically, both the extent and the direction of reward-based adjustments are further predicted by personality traits indexing reward sensitivity, indicating that not only male and female brains are differentially sensitive to reward, but also that specific personality traits further contribute to shaping their learning-dependent attentional plasticity. These results contribute to a better understanding of the neurobiology underlying reward-dependent attentional learning and cross-subject variability in this domain.

  2. Research priorities about stoma-related quality of life from the perspective of people with a stoma: A pilot survey.

    PubMed

    Hubbard, Gill; Taylor, Claire; Beeken, Becca; Campbell, Anna; Gracey, Jackie; Grimmett, Chloe; Fisher, Abi; Ozakinci, Gozde; Slater, Sarah; Gorely, Trish

    2017-12-01

    There is a recognized need to include patients in setting research priorities. Research priorities identified by people with a stoma are rarely elicited. To improve the quality of life of people with a stoma through use of evidence-based practice based on research priorities set by patients. Online pilot survey publicized in 2016 via United Kingdom stoma charities. People ranked nine stoma-related quality of life topics in order of research priority. People 16 years of age and over who currently have or have had a stoma for treatment for any medical condition. Distributions of the priority scores for each of the nine research topics were examined. Group differences were explored using either the Mann-Whitney U-test or the Kruskal-Wallis test depending on the number of groups. In total, 225 people completed the survey. The most important research priority was pouch leak problems and stoma bag/appliance problems followed by hernia risk. There were statistically significant differences in ranking research priorities between males and females, age, underlying disease that led to a stoma, stoma type and length of time with a stoma. People with a stoma are willing to engage in and set research priorities. The results should contribute towards future research about setting the research agenda for the study of stoma-related concerns that impact quality of life. © 2017 The Authors Health Expectations Published by John Wiley & Sons Ltd.

  3. 78 FR 3934 - Self-Regulatory Organizations; International Securities Exchange, LLC; Notice of Filing and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-17

    ... Symbols, 2) increase the maker fee for complex orders that trade against Priority Customer complex orders... provides volume-based tiered rebates for Priority Customer complex orders in the Select Symbols (excluding... orders trade with non-Priority Customer orders in the complex order book. In the Select Symbols, the...

  4. Adapting Technological Interventions to Meet the Needs of Priority Populations.

    PubMed

    Linke, Sarah E; Larsen, Britta A; Marquez, Becky; Mendoza-Vasconez, Andrea; Marcus, Bess H

    2016-01-01

    Cardiovascular diseases (CVD) comprise the leading cause of mortality worldwide, accounting for 3 in 10 deaths. Individuals with certain risk factors, including tobacco use, obesity, low levels of physical activity, type 2 diabetes mellitus, racial/ethnic minority status and low socioeconomic status, experience higher rates of CVD and are, therefore, considered priority populations. Technological devices such as computers and smartphones are now routinely utilized in research studies aiming to prevent CVD and its risk factors, and they are also rampant in the public and private health sectors. Traditional health behavior interventions targeting these risk factors have been adapted for technology-based approaches. This review provides an overview of technology-based interventions conducted in these priority populations as well as the challenges and gaps to be addressed in future research. Researchers currently possess tremendous opportunities to engage in technology-based implementation and dissemination science to help spread evidence-based programs focusing on CVD risk factors in these and other priority populations. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Contact Graph Routing Enhancements Developed in ION for DTN

    NASA Technical Reports Server (NTRS)

    Segui, John S.; Burleigh, Scott

    2013-01-01

    The Interplanetary Overlay Network (ION) software suite is an open-source, flight-ready implementation of networking protocols including the Delay/Disruption Tolerant Networking (DTN) Bundle Protocol (BP), the CCSDS (Consultative Committee for Space Data Systems) File Delivery Protocol (CFDP), and many others including the Contact Graph Routing (CGR) DTN routing system. While DTN offers the capability to tolerate disruption and long signal propagation delays in transmission, without an appropriate routing protocol, no data can be delivered. CGR was built for space exploration networks with scheduled communication opportunities (typically based on trajectories and orbits), represented as a contact graph. Since CGR uses knowledge of future connectivity, the contact graph can grow rather large, and so efficient processing is desired. These enhancements allow CGR to scale to predicted NASA space network complexities and beyond. This software improves upon CGR by adopting an earliest-arrival-time cost metric and using the Dijkstra path selection algorithm. Moving to Dijkstra path selection also enables construction of an earliest- arrival-time tree for multicast routing. The enhancements have been rolled into ION 3.0 available on sourceforge.net.

  6. 15 CFR 700.14 - Preferential scheduling.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...) BUREAU OF INDUSTRY AND SECURITY, DEPARTMENT OF COMMERCE NATIONAL SECURITY INDUSTRIAL BASE REGULATIONS DEFENSE PRIORITIES AND ALLOCATIONS SYSTEM Industrial Priorities § 700.14 Preferential scheduling. (a) A...

  7. Spatial analysis on school environment characteristics in mangrove management based on local wisdom (Case study at Lhokseumawe, Aceh)

    NASA Astrophysics Data System (ADS)

    Susiloningtyas, Dewi; Handayani, Tuty; Amalia, Naila; Nadhira, Arum Ira

    2017-01-01

    After 2004 tsunami, lots of efforts have been made, such as building school and distributing mangrove forests. This study examines the perception of teachers and students about mangrove management which spread in the administrative area of Lhokseumawe to become a reference then applied as local education regarding mangrove after tsunami disaster. This paper was based on primary data taken using questionnaire with a predetermined analysis unit to interview teachers and students in the study area. The result presented with quantitative and descriptive analysis. The result is of the total number of junior high schools in the city of Lhokseumawe as many as 41 Public Schools, Private and Religious School, there are 31 schools with priority for local wisdom education implemented mangrove. The result is classified with 3 class. The school’s first priority is schools with a melee, with mangroves mangrove poor condition. Educational priority 2 is schools with close proximity to the mangrove and mangrove condition with moderate levels of damage. Schools with third priority are school with a close range, and mangrove good condition. Priority I as many as 18 schools, 10 schools priority II and 3 school for priority with learning competency standards that differ from each other.

  8. A hazy outlook for cloud computing.

    PubMed

    Perna, Gabriel

    2012-01-01

    Because of competing priorities as well as cost, security, and implementation concerns, cloud-based storage development has gotten off to a slow start in healthcare. CIOs, CTOs, and other healthcare IT leaders are adopting a variety of strategies in this area, based on their organizations' needs, resources, and priorities.

  9. Development of maintenance composite priority index for buildings in Palestine: A pilot case study

    NASA Astrophysics Data System (ADS)

    Issa, Amjad; Awad, Riyad

    2017-11-01

    The current building maintenance practices in Palestine are not based on scientific systematic methods. Most of the municipalities use one criterion to define the maintenance priorities, which is the "worst-first" criterion. Therefore, the current practices in defining buildings maintenance plans are not dealing with the known phases that are generally followed, including those in establishing building inventories, building condition survey, detailed visual inspection, identification of the proper maintenance and rehabilitation measures, and setting priorities. Accordingly, the recent preparation of the Operation and Maintenance (O&M) Manual for Palestinian municipalities is an important step to guide them towards preparing and implementing their O&M priority-based plans, considering scare resources. During the course of preparation of the Manual, the proposed procedures were applied at ten pilot municipalities. This study aims to explore the outcome of the implementation of the 2014/2015 O&M buildings maintenance priorities at these municipalities through the development of maintenance composite priority index (PI). The new proposed priority index is a scientific tool that will identify the priority of maintenance buildings through using a systematic procedure instead of first worst one. To achieve this, analyses of the outcome of a questionnaire designed to collect relevant information from these municipalities was conducted. The maintenance priority index for buildings is calculated considering different indicators among them building status (condition), classification and importance of the building, number of beneficiaries (users), safety aspects (severity level in the building), and people complaints. The main component of the PI is the building condition index (BCI) which forms about 40% of the total weight. The physical inspection, which is the main input for calculating the BCI, is conducted on two levels; the primary level, and the secondary level. The buildings are ranked in descending order based on the PI values for each public building. The buildings that have the highest values of PI take the most priority till the specified asset maintenance budget for the targeted year is achieved. Finally, the results indicate that most of the maintenance works are funded by municipalities own budgets and not by the government.

  10. 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.

  11. Identifying conservation priorities and management strategies based on ecosystem services to improve urban sustainability in Harbin, China

    PubMed Central

    2018-01-01

    Rapid urbanization and agricultural development has resulted in the degradation of ecosystems, while also negatively impacting ecosystem services (ES) and urban sustainability. Identifying conservation priorities for ES and applying reasonable management strategies have been found to be effective methods for mitigating this phenomenon. The purpose of this study is to propose a comprehensive framework for identifying ES conservation priorities and associated management strategies for these planning areas. First, we incorporated 10 ES indicators within a systematic conservation planning (SCP) methodology in order to identify ES conservation priorities with high irreplaceability values based on conservation target goals associated with the potential distribution of ES indicators. Next, we assessed the efficiency of the ES conservation priorities for meeting the designated conservation target goals. Finally, ES conservation priorities were clustered into groups using a K-means clustering analysis in an effort to identify the dominant ES per location before formulating management strategies. We effectively identified 12 ES priorities to best represent conservation target goals for the ES indicators. These 12 priorities had a total areal coverage of 13,364 km2 representing 25.16% of the study area. The 12 priorities were further clustered into five significantly different groups (p-values between groups < 0.05), which helped to refine management strategies formulated to best enhance ES across the study area. The proposed method allows conservation and management plans to easily adapt to a wide variety of quantitative ES target goals within urban and agricultural areas, thereby preventing urban and agriculture sprawl and guiding sustainable urban development. PMID:29682412

  12. Identifying conservation priorities and management strategies based on ecosystem services to improve urban sustainability in Harbin, China.

    PubMed

    Qu, Yi; Lu, Ming

    2018-01-01

    Rapid urbanization and agricultural development has resulted in the degradation of ecosystems, while also negatively impacting ecosystem services (ES) and urban sustainability. Identifying conservation priorities for ES and applying reasonable management strategies have been found to be effective methods for mitigating this phenomenon. The purpose of this study is to propose a comprehensive framework for identifying ES conservation priorities and associated management strategies for these planning areas. First, we incorporated 10 ES indicators within a systematic conservation planning (SCP) methodology in order to identify ES conservation priorities with high irreplaceability values based on conservation target goals associated with the potential distribution of ES indicators. Next, we assessed the efficiency of the ES conservation priorities for meeting the designated conservation target goals. Finally, ES conservation priorities were clustered into groups using a K-means clustering analysis in an effort to identify the dominant ES per location before formulating management strategies. We effectively identified 12 ES priorities to best represent conservation target goals for the ES indicators. These 12 priorities had a total areal coverage of 13,364 km 2 representing 25.16% of the study area. The 12 priorities were further clustered into five significantly different groups ( p -values between groups < 0.05), which helped to refine management strategies formulated to best enhance ES across the study area. The proposed method allows conservation and management plans to easily adapt to a wide variety of quantitative ES target goals within urban and agricultural areas, thereby preventing urban and agriculture sprawl and guiding sustainable urban development.

  13. 77 FR 58424 - Self-Regulatory Organizations; International Securities Exchange, LLC; Notice of Filing and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-20

    ... Priority Customer complex orders that they send to the Exchange in these symbols. In the Select Symbols, the Exchange currently provides a base rebate of $0.34 per contract, per leg, for Priority Customer complex orders when these orders trade with non-Priority Customer complex orders in the complex order book...

  14. Cost-effective priorities for global mammal conservation.

    PubMed

    Carwardine, Josie; Wilson, Kerrie A; Ceballos, Gerardo; Ehrlich, Paul R; Naidoo, Robin; Iwamura, Takuya; Hajkowicz, Stefan A; Possingham, Hugh P

    2008-08-12

    Global biodiversity priority setting underpins the strategic allocation of conservation funds. In identifying the first comprehensive set of global priority areas for mammals, Ceballos et al. [Ceballos G, Ehrlich PR, Soberón J, Salazar I, Fay JP (2005) Science 309:603-607] found much potential for conflict between conservation and agricultural human activity. This is not surprising because, like other global priority-setting approaches, they set priorities without socioeconomic objectives. Here we present a priority-setting framework that seeks to minimize the conflicts and opportunity costs of meeting conservation goals. We use it to derive a new set of priority areas for investment in mammal conservation based on (i) agricultural opportunity cost and biodiversity importance, (ii) current levels of international funding, and (iii) degree of threat. Our approach achieves the same biodiversity outcomes as Ceballos et al.'s while reducing the opportunity costs and conflicts with agricultural human activity by up to 50%. We uncover shortfalls in the allocation of conservation funds in many threatened priority areas, highlighting a global conservation challenge.

  15. The kidney cancer research priority-setting partnership: Identifying the top 10 research priorities as defined by patients, caregivers, and expert clinicians.

    PubMed

    Jones, Jennifer; Bhatt, Jaimin; Avery, Jonathan; Laupacis, Andreas; Cowan, Katherine; Basappa, Naveen; Basiuk, Joan; Canil, Christina; Al-Asaaed, Sohaib; Heng, Daniel; Wood, Lori; Stacey, Dawn; Kollmannsberger, Christian; Jewett, Michael A S

    2017-12-01

    It is critically important to define disease-specific research priorities to better allocate limited resources. There is growing recognition of the value of involving patients and caregivers, as well as expert clinicians in this process. To our knowledge, this has not been done this way for kidney cancer. Using the transparent and inclusive process established by the James Lind Alliance, the Kidney Cancer Research Network of Canada (KCRNC) sponsored a collaborative consensus-based priority-setting partnership (PSP) to identify research priorities in the management of kidney cancer. The final result was identification of 10 research priorities for kidney cancer, which are discussed in the context of current initiatives and gaps in knowledge. This process provided a systematic and effective way to collaboratively establish research priorities with patients, caregivers, and clinicians, and provides a valuable resource for researchers and funding agencies.

  16. Aligning organizational priorities with ARC to improve youth mental health service outcomes.

    PubMed

    Glisson, Charles; Williams, Nathaniel J; Hemmelgarn, Anthony; Proctor, Enola; Green, Philip

    2016-08-01

    The Availability, Responsiveness, and Continuity (ARC) organizational intervention is designed to improve community-based youth mental health services by aligning organizational priorities with 5 principles of effective service organizations (i.e., mission driven, results oriented, improvement directed, relationship centered, participation based). This study assessed the effect of the ARC intervention on youth outcomes and the mediating role of organizational priorities as a mechanism linking the ARC intervention to outcomes. Fourteen community-based mental health agencies in a midwestern metropolis along with 475 clinicians and 605 youth (ages 5-18) served by those agencies were randomly assigned to the 3-year ARC intervention or control condition. The agencies' priorities were measured with the ARC Principles Questionnaire (APQ) completed by clinicians at the end of the intervention. Youth outcomes were measured as total problems in psychosocial functioning described by their caregivers using the Shortform Assessment for Children (SAC) at 6 monthly intervals. The rate of improvement in youths' psychosocial functioning in agencies assigned to the ARC condition was 1.6 times the rate of improvement in agencies assigned to the control condition, creating a standardized difference in functioning of d = .23 between the 2 groups at the 6-month follow-up. The effect on youth outcomes was fully mediated by the alignment of organizational priorities described in the 5 ARC principles (d = .21). The ARC organizational intervention improves youth outcomes by aligning organizational priorities with the 5 ARC principles. The findings suggest that organizational priorities explain why some community mental health agencies are more effective than others. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  17. Aligning Organizational Priorities with ARC to Improve Youth Mental Health Service Outcomes

    PubMed Central

    Glisson, Charles; Williams, Nathaniel J.; Hemmelgarn, Anthony; Procter, Enola; Green, Philip

    2016-01-01

    Objective The ARC organizational intervention was designed to improve community-based youth mental health services by aligning organizational priorities with five principles of effective service organizations (i.e., mission-driven, results-oriented, improvement-directed, relationship-centered, participation-based). This study assessed the effect of the ARC intervention on youth outcomes and the mediating role of organizational priorities as a mechanism linking the ARC intervention to outcomes. Methodology Fourteen community-based mental health agencies in a Midwestern metropolis along with 475 clinicians and 605 youth (aged 5–18) served by those agencies were randomly assigned to the three-year ARC intervention or control condition. The agencies’ priorities were measured with the ARC Principles Questionnaire (APQ) completed by clinicians at the end of the intervention. Youth outcomes were measured as total problems in psychosocial functioning described by their caregivers using the Shortform Assessment for Children (SAC) at six monthly intervals. Results The rate of improvement in youths’ psychosocial functioning in agencies assigned to the ARC condition was 1.6 times the rate of improvement in agencies assigned to the control condition, creating a standardized difference in functioning of d = .23 between the two groups at the six month follow-up. The effect on youth outcomes was fully mediated by the alignment of organizational priorities described in the five ARC principles (d = .21). Conclusions The ARC organizational intervention improves youth outcomes by aligning organizational priorities with the five ARC principles. The findings suggest that organizational priorities explain why some community mental health agencies are more effective than others. PMID:27253202

  18. Systematic Review of Real-time Remote Health Monitoring System in Triage and Priority-Based Sensor Technology: Taxonomy, Open Challenges, Motivation and Recommendations.

    PubMed

    Albahri, O S; Albahri, A S; Mohammed, K I; Zaidan, A A; Zaidan, B B; Hashim, M; Salman, Omar H

    2018-03-22

    The new and ground-breaking real-time remote monitoring in triage and priority-based sensor technology used in telemedicine have significantly bounded and dispersed communication components. To examine these technologies and provide researchers with a clear vision of this area, we must first be aware of the utilised approaches and existing limitations in this line of research. To this end, an extensive search was conducted to find articles dealing with (a) telemedicine, (b) triage, (c) priority and (d) sensor; (e) comprehensively review related applications and establish the coherent taxonomy of these articles. ScienceDirect, IEEE Xplore and Web of Science databases were checked for articles on triage and priority-based sensor technology in telemedicine. The retrieved articles were filtered according to the type of telemedicine technology explored. A total of 150 articles were selected and classified into two categories. The first category includes reviews and surveys of triage and priority-based sensor technology in telemedicine. The second category includes articles on the three-tiered architecture of telemedicine. Tier 1 represents the users. Sensors acquire the vital signs of the users and send them to Tier 2, which is the personal gateway that uses local area network protocols or wireless body area network. Medical data are sent from Tier 2 to Tier 3, which is the healthcare provider in medical institutes. Then, the motivation for using triage and priority-based sensor technology in telemedicine, the issues related to the obstruction of its application and the development and utilisation of telemedicine are examined on the basis of the findings presented in the literature.

  19. Discovering Socialization Priorities in Turkish Society Based on What the Value of Success Means

    ERIC Educational Resources Information Center

    Aypay, Ayse

    2016-01-01

    The purpose of this study is to discover socialization priorities based on what the value of success means in Turkish society. For this purpose, two related scales have been developed to identify the beliefs of adults in Turkish society towards defining the value of success and the areas in which adults perceive themselves as successful based on…

  20. Integrated approach for prioritizing watersheds for management: a study of lidder catchment of kashmir himalayas.

    PubMed

    Malik, Mohammad Imran; Bhat, M Sultan

    2014-12-01

    The Himalayan watersheds are susceptible to various forms of degradation due to their sensitive and fragile ecological disposition coupled with increasing anthropogenic disturbances. Owing to the paucity of appropriate technology and financial resources, the prioritization of watersheds has become an inevitable process for effective planning and management of natural resources. Lidder catchment constitutes a segment of the western Himalayas with an area of 1,159.38 km(2). The study is based on integrated analysis of remote sensing, geographic information system, field study, and socioeconomic data. Multicriteria evaluation of geophysical, land-use and land-cover (LULC) change, and socioeconomic indicators is carried out to prioritize watersheds for natural resource conservation and management. Knowledge-based weights and ranks are normalized, and weighted linear combination technique is adopted to determine final priority value. The watersheds are classified into four priority zones (very high priority, high priority, medium priority, and low priority) on the basis of quartiles of the priority value, thus indicating their ecological status in terms of degradation caused by anthropogenic disturbances. The correlation between priority ranks of individual indicators and integrated indicators is drawn. The results reveal that socioeconomic indicators are the most important drivers of LULC change and environmental degradation in the catchment. Moreover, the magnitude and intensity of anthropogenic impact is not uniform in different watersheds of Lidder catchment. Therefore, any conservation and management strategy must be formulated on the basis of watershed prioritization.

  1. Integrated Approach for Prioritizing Watersheds for Management: A Study of Lidder Catchment of Kashmir Himalayas

    NASA Astrophysics Data System (ADS)

    Malik, Mohammad Imran; Bhat, M. Sultan

    2014-12-01

    The Himalayan watersheds are susceptible to various forms of degradation due to their sensitive and fragile ecological disposition coupled with increasing anthropogenic disturbances. Owing to the paucity of appropriate technology and financial resources, the prioritization of watersheds has become an inevitable process for effective planning and management of natural resources. Lidder catchment constitutes a segment of the western Himalayas with an area of 1,159.38 km2. The study is based on integrated analysis of remote sensing, geographic information system, field study, and socioeconomic data. Multicriteria evaluation of geophysical, land-use and land-cover (LULC) change, and socioeconomic indicators is carried out to prioritize watersheds for natural resource conservation and management. Knowledge-based weights and ranks are normalized, and weighted linear combination technique is adopted to determine final priority value. The watersheds are classified into four priority zones (very high priority, high priority, medium priority, and low priority) on the basis of quartiles of the priority value, thus indicating their ecological status in terms of degradation caused by anthropogenic disturbances. The correlation between priority ranks of individual indicators and integrated indicators is drawn. The results reveal that socioeconomic indicators are the most important drivers of LULC change and environmental degradation in the catchment. Moreover, the magnitude and intensity of anthropogenic impact is not uniform in different watersheds of Lidder catchment. Therefore, any conservation and management strategy must be formulated on the basis of watershed prioritization.

  2. Multimedia And Internetworking Architecture Infrastructure On Interactive E-Learning System

    NASA Astrophysics Data System (ADS)

    Indah, K. A. T.; Sukarata, G.

    2018-01-01

    Interactive e-learning is a distance learning method that involves information technology, electronic system or computer as one means of learning system used for teaching and learning process that is implemented without having face to face directly between teacher and student. A strong dependence on emerging technologies greatly influences the way in which the architecture is designed to produce a powerful interactive e-learning network. In this paper analyzed an architecture model where learning can be done interactively, involving many participants (N-way synchronized distance learning) using video conferencing technology. Also used broadband internet network as well as multicast techniques as a troubleshooting method for bandwidth usage can be efficient.

  3. ISIS and META projects

    NASA Technical Reports Server (NTRS)

    Birman, Kenneth; Cooper, Robert; Marzullo, Keith

    1990-01-01

    The ISIS project has developed a new methodology, virtual synchony, for writing robust distributed software. High performance multicast, large scale applications, and wide area networks are the focus of interest. Several interesting applications that exploit the strengths of ISIS, including an NFS-compatible replicated file system, are being developed. The META project is distributed control in a soft real-time environment incorporating feedback. This domain encompasses examples as diverse as monitoring inventory and consumption on a factory floor, and performing load-balancing on a distributed computing system. One of the first uses of META is for distributed application management: the tasks of configuring a distributed program, dynamically adapting to failures, and monitoring its performance. Recent progress and current plans are reported.

  4. The effectiveness of surrogate taxa to conserve freshwater biodiversity

    USGS Publications Warehouse

    Stewart, David R.; Underwood, Zachary E.; Rahel, Frank J.; Walters, Annika W.

    2018-01-01

    Establishing protected areas has long been an effective conservation strategy, and is often based on more readily surveyed species. The potential of any freshwater taxa to be a surrogate of other aquatic groups has not been fully explored. We compiled occurrence data on 72 species of freshwater fish, amphibians, mussels, and aquatic reptiles for the Great Plains, Wyoming. We used hierarchical Bayesian multi-species mixture models and MaxEnt models to describe species distributions, and program Zonation to identify conservation priority areas for each aquatic group. The landscape-scale factors that best characterized aquatic species distributions differed among groups. There was low agreement and congruence among taxa-specific conservation priorities (<20%), meaning that no surrogate priority areas would include or protect the best habitats of other aquatic taxa. We found that common, wide-ranging aquatic species were included in taxa-specific priority areas, but rare freshwater species were not included. Thus, the development of conservation priorities based on a single freshwater aquatic group would not protect all species in the other aquatic groups.

  5. Priority setting in healthcare: towards guidelines for the program budgeting and marginal analysis framework.

    PubMed

    Peacock, Stuart J; Mitton, Craig; Ruta, Danny; Donaldson, Cam; Bate, Angela; Hedden, Lindsay

    2010-10-01

    Economists' approaches to priority setting focus on the principles of opportunity cost, marginal analysis and choice under scarcity. These approaches are based on the premise that it is possible to design a rational priority setting system that will produce legitimate changes in resource allocation. However, beyond issuing guidance at the national level, economic approaches to priority setting have had only a moderate impact in practice. In particular, local health service organizations - such as health authorities, health maintenance organizations, hospitals and healthcare trusts - have had difficulty implementing evidence from economic appraisals. Yet, in the context of making decisions between competing claims on scarce health service resources, economic tools and thinking have much to offer. The purpose of this article is to describe and discuss ten evidence-based guidelines for the successful design and implementation of a program budgeting and marginal analysis (PBMA) priority setting exercise. PBMA is a framework that explicitly recognizes the need to balance pragmatic and ethical considerations with economic rationality when making resource allocation decisions. While the ten guidelines are drawn from the PBMA framework, they may be generalized across a range of economic approaches to priority setting.

  6. Trends in municipal-well installations and aquifer utilization in southeastern Minnesota, 1880-1980

    USGS Publications Warehouse

    Woodward, D.G.

    1985-01-01

    Water appropriation in Minnesota is regulated through a permit system based on five water-use priorities. Domestic water supply, excluding industrial and commercial uses of a municipal water supply, is the highest priority (Minnesota Statutes, Chapter 105.41). Under the regulations, uses of a lower priority are not permitted to adversely affect uses of a higher priority. Identification of the aquifer(s) used for municipal supplies is also necessary to safeguard these supplies from adverse effects of competing water users and contamination, and to evaluate the consequences of each.

  7. Setting Research Priorities for Kidney Cancer.

    PubMed

    Jones, Jennifer M; Bhatt, Jaimin; Avery, Jonathan; Laupacis, Andreas; Cowan, Katherine; Basappa, Naveen S; Basiuk, Joan; Canil, Christina; Al-Asaaed, Sohaib; Heng, Daniel Y C; Wood, Lori; Stacey, Dawn; Kollmannsberger, Christian; Jewett, Michael A S

    2017-12-01

    Defining disease-specific research priorities in cancer can facilitate better allocation of limited resources. Involving patients and caregivers as well as expert clinicians in this process is of value. We undertook this approach for kidney cancer as an example. The Kidney Cancer Research Network of Canada sponsored a collaborative consensus-based priority-setting partnership that identified ten research priorities in the management of kidney cancer. These are discussed in the context of current initiatives and gaps in knowledge. Copyright © 2017 European Association of Urology. Published by Elsevier B.V. All rights reserved.

  8. Unequal error control scheme for dimmable visible light communication systems

    NASA Astrophysics Data System (ADS)

    Deng, Keyan; Yuan, Lei; Wan, Yi; Li, Huaan

    2017-01-01

    Visible light communication (VLC), which has the advantages of a very large bandwidth, high security, and freedom from license-related restrictions and electromagnetic-interference, has attracted much interest. Because a VLC system simultaneously performs illumination and communication functions, dimming control, efficiency, and reliable transmission are significant and challenging issues of such systems. In this paper, we propose a novel unequal error control (UEC) scheme in which expanding window fountain (EWF) codes in an on-off keying (OOK)-based VLC system are used to support different dimming target values. To evaluate the performance of the scheme for various dimming target values, we apply it to H.264 scalable video coding bitstreams in a VLC system. The results of the simulations that are performed using additive white Gaussian noises (AWGNs) with different signal-to-noise ratios (SNRs) are used to compare the performance of the proposed scheme for various dimming target values. It is found that the proposed UEC scheme enables earlier base layer recovery compared to the use of the equal error control (EEC) scheme for different dimming target values and therefore afford robust transmission for scalable video multicast over optical wireless channels. This is because of the unequal error protection (UEP) and unequal recovery time (URT) of the EWF code in the proposed scheme.

  9. Improving P2P live-content delivery using SVC

    NASA Astrophysics Data System (ADS)

    Schierl, T.; Sánchez, Y.; Hellge, C.; Wiegand, T.

    2010-07-01

    P2P content delivery techniques for video transmission have become of high interest in the last years. With the involvement of client into the delivery process, P2P approaches can significantly reduce the load and cost on servers, especially for popular services. However, previous studies have already pointed out the unreliability of P2P-based live streaming approaches due to peer churn, where peers may ungracefully leave the P2P infrastructure, typically an overlay networks. Peers ungracefully leaving the system cause connection losses in the overlay, which require repair operations. During such repair operations, which typically take a few roundtrip times, no data is received from the lost connection. While taking low delay for fast-channel tune-in into account as a key feature for broadcast-like streaming applications, the P2P live streaming approach can only rely on a certain media pre-buffer during such repair operations. In this paper, multi-tree based Application Layer Multicast as a P2P overlay technique for live streaming is considered. The use of Flow Forwarding (FF), a.k.a. Retransmission, or Forward Error Correction (FEC) in combination with Scalable video Coding (SVC) for concealment during overlay repair operations is shown. Furthermore the benefits of using SVC over the use of AVC single layer transmission are presented.

  10. A generic flexible and robust approach for intelligent real-time video-surveillance systems

    NASA Astrophysics Data System (ADS)

    Desurmont, Xavier; Delaigle, Jean-Francois; Bastide, Arnaud; Macq, Benoit

    2004-05-01

    In this article we present a generic, flexible and robust approach for an intelligent real-time video-surveillance system. A previous version of the system was presented in [1]. The goal of these advanced tools is to provide help to operators by detecting events of interest in visual scenes and highlighting alarms and compute statistics. The proposed system is a multi-camera platform able to handle different standards of video inputs (composite, IP, IEEE1394 ) and which can basically compress (MPEG4), store and display them. This platform also integrates advanced video analysis tools, such as motion detection, segmentation, tracking and interpretation. The design of the architecture is optimised to playback, display, and process video flows in an efficient way for video-surveillance application. The implementation is distributed on a scalable computer cluster based on Linux and IP network. It relies on POSIX threads for multitasking scheduling. Data flows are transmitted between the different modules using multicast technology and under control of a TCP-based command network (e.g. for bandwidth occupation control). We report here some results and we show the potential use of such a flexible system in third generation video surveillance system. We illustrate the interest of the system in a real case study, which is the indoor surveillance.

  11. A survey of time management and particular tasks undertaken by consultant microbiologists in the UK.

    PubMed

    Riordan, Terry; Cartwright, Keith; Cunningham, Richard; Logan, Margaret; Wright, Paul

    2007-05-01

    Medical microbiology practice encompasses a diverse range of activities. Consultant medical microbiologists (CMMs) attribute widely differing priorities to, and spend differing proportions of time on various components of the job. To obtain a professional consensus on what are high-priority and low-priority activities, and to identify the time spent on low-priority activities. National survey. Many respondents felt that time spent on report authorisation and telephoning of results was excessive, whereas time spent on ward-based work was inadequate. Timesaving could also be achieved through better prioritisation of infection-control activities. CMMs should apportion their time at work focusing on high-priority activities identified through professional consensus.

  12. Priority and Negotiation Based Dynamic Spectrum Allocation Scheme for Multiple Radio Access Network Operators

    NASA Astrophysics Data System (ADS)

    Kim, Hoon; Hyon, Taein; Lee, Yeonwoo

    Most of previous works have presented the dynamic spectrum allocation (DSA) gain achieved by utilizing the time or regional variations in traffic demand between multi-network operators (NOs). In this paper, we introduce the functionalities required for the entities related with the spectrum sharing and allocation and propose a spectrum allocation algorithm while considering the long-term priority between NOs, the priority between multiple class services, and the urgent bandwidth request. To take into account the priorities among the NOs and the priorities of multiple class services, a spectrum sharing metric (SSM) is proposed, while a negotiation procedure is proposed to treat the urgent bandwidth request.

  13. 15 CFR 700.17 - Use of rated orders.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...) BUREAU OF INDUSTRY AND SECURITY, DEPARTMENT OF COMMERCE NATIONAL SECURITY INDUSTRIAL BASE REGULATIONS DEFENSE PRIORITIES AND ALLOCATIONS SYSTEM Industrial Priorities § 700.17 Use of rated orders. (a) A person...

  14. Improving the Teaching of Evidence-Based Practice: Challenges and Priorities

    ERIC Educational Resources Information Center

    Soydan, Haluk

    2007-01-01

    This article explores some of the main challenges of improving the teaching of evidence-based practice in schools of social work. The priority challenges are the needs for a general professional cultural shift, for adequate curricula, to overcome the controversy of scientific methodology, to better understand the state of the art of the…

  15. Typology of end-of-life priorities in Saudi females: averaging analysis and Q-methodology.

    PubMed

    Hammami, Muhammad M; Hammami, Safa; Amer, Hala A; Khodr, Nesrine A

    2016-01-01

    Understanding culture-and sex-related end-of-life preferences is essential to provide quality end-of-life care. We have previously explored end-of-life choices in Saudi males and found important culture-related differences and that Q-methodology is useful in identifying intraculture, opinion-based groups. Here, we explore Saudi females' end-of-life choices. A volunteer sample of 68 females rank-ordered 47 opinion statements on end-of-life issues into a nine-category symmetrical distribution. The ranking scores of the statements were analyzed by averaging analysis and Q-methodology. The mean age of the females in the sample was 30.3 years (range, 19-55 years). Among them, 51% reported average religiosity, 78% reported very good health, 79% reported very good life quality, and 100% reported high-school education or more. The extreme five overall priorities were to be able to say the statement of faith, be at peace with God, die without having the body exposed, maintain dignity, and resolve all conflicts. The extreme five overall dis-priorities were to die in the hospital, die well dressed, be informed about impending death by family/friends rather than doctor, die at peak of life, and not know if one has a fatal illness. Q-methodology identified five opinion-based groups with qualitatively different characteristics: "physical and emotional privacy concerned, family caring" (younger, lower religiosity), "whole person" (higher religiosity), "pain and informational privacy concerned" (lower life quality), "decisional privacy concerned" (older, higher life quality), and "life quantity concerned, family dependent" (high life quality, low life satisfaction). Out of the extreme 14 priorities/dis-priorities for each group, 21%-50% were not represented among the extreme 20 priorities/dis-priorities for the entire sample. Consistent with the previously reported findings in Saudi males, transcendence and dying in the hospital were the extreme end-of-life priority and dis-priority, respectively, in Saudi females. Body modesty was a major overall concern; however, concerns about pain, various types of privacy, and life quantity were variably emphasized by the five opinion-based groups but masked by averaging analysis.

  16. Typology of end-of-life priorities in Saudi females: averaging analysis and Q-methodology

    PubMed Central

    Hammami, Muhammad M; Hammami, Safa; Amer, Hala A; Khodr, Nesrine A

    2016-01-01

    Background Understanding culture-and sex-related end-of-life preferences is essential to provide quality end-of-life care. We have previously explored end-of-life choices in Saudi males and found important culture-related differences and that Q-methodology is useful in identifying intraculture, opinion-based groups. Here, we explore Saudi females’ end-of-life choices. Methods A volunteer sample of 68 females rank-ordered 47 opinion statements on end-of-life issues into a nine-category symmetrical distribution. The ranking scores of the statements were analyzed by averaging analysis and Q-methodology. Results The mean age of the females in the sample was 30.3 years (range, 19–55 years). Among them, 51% reported average religiosity, 78% reported very good health, 79% reported very good life quality, and 100% reported high-school education or more. The extreme five overall priorities were to be able to say the statement of faith, be at peace with God, die without having the body exposed, maintain dignity, and resolve all conflicts. The extreme five overall dis-priorities were to die in the hospital, die well dressed, be informed about impending death by family/friends rather than doctor, die at peak of life, and not know if one has a fatal illness. Q-methodology identified five opinion-based groups with qualitatively different characteristics: “physical and emotional privacy concerned, family caring” (younger, lower religiosity), “whole person” (higher religiosity), “pain and informational privacy concerned” (lower life quality), “decisional privacy concerned” (older, higher life quality), and “life quantity concerned, family dependent” (high life quality, low life satisfaction). Out of the extreme 14 priorities/dis-priorities for each group, 21%–50% were not represented among the extreme 20 priorities/dis-priorities for the entire sample. Conclusion Consistent with the previously reported findings in Saudi males, transcendence and dying in the hospital were the extreme end-of-life priority and dis-priority, respectively, in Saudi females. Body modesty was a major overall concern; however, concerns about pain, various types of privacy, and life quantity were variably emphasized by the five opinion-based groups but masked by averaging analysis. PMID:27274205

  17. Use of demand for and spatial flow of ecosystem services to identify priority areas.

    PubMed

    Verhagen, Willem; Kukkala, Aija S; Moilanen, Atte; van Teeffelen, Astrid J A; Verburg, Peter H

    2017-08-01

    Policies and research increasingly focus on the protection of ecosystem services (ESs) through priority-area conservation. Priority areas for ESs should be identified based on ES capacity and ES demand and account for the connections between areas of ES capacity and demand (flow) resulting in areas of unique demand-supply connections (flow zones). We tested ways to account for ES demand and flow zones to identify priority areas in the European Union. We mapped the capacity and demand of a global (carbon sequestration), a regional (flood regulation), and 3 local ESs (air quality, pollination, and urban leisure). We used Zonation software to identify priority areas for ESs based on 6 tests: with and without accounting for ES demand and 4 tests that accounted for the effect of ES flow zone. There was only 37.1% overlap between the 25% of priority areas that encompassed the most ESs with and without accounting for ES demand. The level of ESs maintained in the priority areas increased from 23.2% to 57.9% after accounting for ES demand, especially for ESs with a small flow zone. Accounting for flow zone had a small effect on the location of priority areas and level of ESs maintained but resulted in fewer flow zones without ES maintained relative to ignoring flow zones. Accounting for demand and flow zones enhanced representation and distribution of ESs with local to regional flow zones without large trade-offs relative to the global ES. We found that ignoring ES demand led to the identification of priority areas in remote regions where benefits from ES capacity to society were small. Incorporating ESs in conservation planning should therefore always account for ES demand to identify an effective priority network for ESs. © 2016 The Authors. Conservation Biology published by Wiley Periodicals, Inc. on behalf of Society for Conservation Biology.

  18. Exploring stakeholders' views of medical education research priorities: a national survey.

    PubMed

    Dennis, Ashley A; Cleland, Jennifer A; Johnston, Peter; Ker, Jean S; Lough, Murray; Rees, Charlotte E

    2014-11-01

    Setting research priorities is important when exploring complex issues with limited resources. Only two countries (Canada and New Zealand) have previously conducted priority-setting exercises for medical education research (MER). This study aimed to identify the views of multiple stakeholders on MER priorities in Scotland. This study utilised a two-stage design to explore the views of stakeholders across the medical education continuum using online questionnaires. In Stage 1, key informants outlined their top three MER priorities and justified their choices. In Stage 2, participants rated 21 topics generated in Stage 1 according to importance and identified or justified their top priorities. A combination of qualitative (i.e. framework analysis) and quantitative (e.g. exploratory factor analysis) data analyses were employed. Views were gathered from over 1300 stakeholders. A total of 21 subthemes (or priority areas) identified in Stage 1 were explored further in Stage 2. The 21 items loaded onto five factors: the culture of learning together in the workplace; enhancing and valuing the role of educators; curriculum integration and innovation; bridging the gap between assessment and feedback, and building a resilient workforce. Within Stage 2, the top priority subthemes were: balancing conflicts between service and training; providing useful feedback; promoting resiliency and well-being; creating an effective workplace learning culture; selecting and recruiting doctors to reflect need, and ensuring that curricula prepare trainees for practice. Participant characteristics were related to the perceived importance of the factors. Finally, five themes explaining why participants prioritised items were identified: patient safety; quality of care; investing for the future; policy and political agendas, and evidence-based education. This study indicates that, across the spectrum of stakeholders and geography, certain MER priorities are consistently identified. These priority areas are in harmony with a range of current drivers in UK medical education. They provide a platform of evidence on which to base decisions about MER programmes in Scotland and beyond. © 2014 John Wiley & Sons Ltd.

  19. Federal Agency Hazardous Waste Compliance Docket

    EPA Pesticide Factsheets

    List of the Federal Agency Hazardous Waste Compliance Docket Facilities comprised of four lists: National Priorities List (NPL), Non-National Priorities List, Base Realignment and Closure Act (BRAC), and Resource Conservation and Recovery Act (RCRA).

  20. Research priorities for adolescent health in low- and middle-income countries: A mixed-methods synthesis of two separate exercises.

    PubMed

    Nagata, Jason M; Hathi, Sejal; Ferguson, B Jane; Hindin, Michele J; Yoshida, Sachiyo; Ross, David A

    2018-06-01

    In order to clarify priorities and stimulate research in adolescent health in low- and middle-income countries (LMICs), the World Health Organization (WHO) conducted two priority-setting exercises based on the Child Health and Nutrition Research Initiative (CHNRI) methodology related to 1) adolescent sexual and reproductive health and 2) eight areas of adolescent health including communicable diseases prevention and management, injuries and violence, mental health, non-communicable diseases management, nutrition, physical activity, substance use, and health policy. Although the CHNRI methodology has been utilized in over 50 separate research priority setting exercises, none have qualitatively synthesized the ultimate findings across studies. The purpose of this study was to conduct a mixed-method synthesis of two research priority-setting exercises for adolescent health in LMICs based on the CHNRI methodology and to situate the priority questions within the current global health agenda. All of the 116 top-ranked questions presented in each exercise were analyzed by two independent reviewers. Word clouds were generated based on keywords from the top-ranked questions. Questions were coded and content analysis was conducted based on type of delivery platform, vulnerable populations, and the Survive, Thrive, and Transform framework from the United Nations Global Strategy for Women's, Children's, and Adolescents' Health, 2016-2030. Within the 53 top-ranked intervention-related questions that specified a delivery platform, the platforms specified were schools (n = 17), primary care (n = 12), community (n = 11), parenting (n = 6), virtual media (n = 5), and peers (n = 2). Twenty questions specifically focused on vulnerable adolescents, including those living with HIV, tuberculosis, mental illness, or neurodevelopmental disorders; victims of gender-based violence; refugees; young persons who inject drugs; sex workers; slum dwellers; out-of-school youth; and youth in armed conflict. A majority of the top-ranked questions (108/116) aligned with one or a combination of the Survive (n = 39), Thrive (n = 67), and Transform (n = 28) agendas. This study advances the CHNRI methodology by conducting the first mixed-methods synthesis of multiple research priority-setting exercises by analyzing keywords (using word clouds) and themes (using content analysis).

  1. Officer Accessions Flow Model

    DTIC Science & Technology

    2011-07-31

    officers select their own BOLC-B dates completely divorced of their unit assignment and that unit’s ARFORGEN cycle. We reschedule all FY10 cohort LTs...for BOLC-B based upon unit priority based upon number of days until LAD. Rescheduling all FY10 cohort LTs for BOLC-B based upon unit priority...with specialty branches (doctors, lawyers, nurses , chaplains, etc) which have minimal representation in BCT-level units.  DCs are not generally

  2. A survey of time management and particular tasks undertaken by consultant microbiologists in the UK

    PubMed Central

    Riordan, Terry; Cartwright, Keith; Cunningham, Richard; Logan, Margaret; Wright, Paul

    2007-01-01

    Background Medical microbiology practice encompasses a diverse range of activities. Consultant medical microbiologists (CMMs) attribute widely differing priorities to, and spend differing proportions of time on various components of the job. Aim To obtain a professional consensus on what are high‐priority and low‐priority activities, and to identify the time spent on low‐priority activities. Method National survey. Results Many respondents felt that time spent on report authorisation and telephoning of results was excessive, whereas time spent on ward‐based work was inadequate. Timesaving could also be achieved through better prioritisation of infection‐control activities. Conclusion CMMs should apportion their time at work focusing on high‐priority activities identified through professional consensus. PMID:16714398

  3. 15 CFR Appendix I to Part 700 - Form BIS-999-Request for Special Priorities Assistance

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... and Foreign Trade (Continued) BUREAU OF INDUSTRY AND SECURITY, DEPARTMENT OF COMMERCE NATIONAL SECURITY INDUSTRIAL BASE REGULATIONS DEFENSE PRIORITIES AND ALLOCATIONS SYSTEM Pt. 700, App. I Appendix I...

  4. Improvement Research Priorities: USA Survey and Expert Consensus

    PubMed Central

    Stevens, Kathleen R.; Ovretveit, John

    2013-01-01

    The purpose of this study was to identify stakeholder views about national priorities for improvement science and build agreement for action in a national improvement and implementation research network in the USA. This was accomplished using three stages of identification and consensus. (1) Topics were identified through a multipronged environmental scan of the literature and initiatives. (2) Based on this scan, a survey was developed, and stakeholders (n = 2,777) were invited to rate the resulting 33-topic, 9-category list, via an online survey. Data from 560 respondents (20% response) were analyzed. (3) An expert panel used survey results to further refine the research priorities through a Rand Delphi process. Priorities identified were within four categories: care coordination and transitions, high-performing clinical systems and microsystems improvement approaches, implementation of evidence-based improvements and best practices, and culture of quality and safety. The priorities identified were adopted by the improvement science research network as the research agenda to guide strategy. The process and conclusions may be of value to quality improvement research funding agencies, governments, and research units seeking to concentrate their resources on improvement topics where research is capable of yielding timely and actionable answers as well as contributing to the knowledge base for improvement. PMID:24024029

  5. Ethics and equity in research priority-setting: stakeholder engagement and the needs of disadvantaged groups.

    PubMed

    Bhaumik, Soumyadeep; Rana, Sangeeta; Karimkhani, Chante; Welch, Vivian; Armstrong, Rebecca; Pottie, Kevin; Dellavalle, Robert; Dhakal, Purushottam; Oliver, Sandy; Francis, Damian K; Nasser, Mona; Crowe, Sally; Aksut, Baran; Amico, Roberto D

    2015-01-01

    A transparent and evidence-based priority-setting process promotes the optimal use of resources to improve health outcomes. Decision-makers and funders have begun to increasingly engage representatives of patients and healthcare consumers to ensure that research becomes more relevant. However, disadvantaged groups and their needs may not be integrated into the priority-setting process since they do not have a "political voice" or are unable to organise into interest groups. Equitable priority-setting methods need to balance patient needs, values, experiences with population-level issues and issues related to the health system.

  6. The effectiveness of surrogate taxa to conserve freshwater biodiversity.

    PubMed

    Stewart, David R; Underwood, Zachary E; Rahel, Frank J; Walters, Annika W

    2018-02-01

    Establishing protected areas has long been an effective conservation strategy and is often based on readily surveyed species. The potential of any freshwater taxa to be a surrogate for other aquatic groups has not been explored fully. We compiled occurrence data on 72 species of freshwater fishes, amphibians, mussels, and aquatic reptiles for the Great Plains, Wyoming (U.S.A.). We used hierarchical Bayesian multispecies mixture models and MaxEnt models to describe species' distributions and the program Zonation to identify areas of conservation priority for each aquatic group. The landscape-scale factors that best characterized aquatic species' distributions differed among groups. There was low agreement and congruence among taxa-specific conservation priorities (<20%), meaning no surrogate priority areas would include or protect the best habitats of other aquatic taxa. Common, wideranging aquatic species were included in taxa-specific priority areas, but rare freshwater species were not included. Thus, the development of conservation priorities based on a single freshwater aquatic group would not protect all species in the other aquatic groups. © 2017 Society for Conservation Biology.

  7. A consensus exercise identifying priorities for research into clinical effectiveness among children's orthopaedic surgeons in the United Kingdom.

    PubMed

    Perry, D C; Wright, J G; Cooke, S; Roposch, A; Gaston, M S; Nicolaou, N; Theologis, T

    2018-05-01

    Aims High-quality clinical research in children's orthopaedic surgery has lagged behind other surgical subspecialties. This study used a consensus-based approach to identify research priorities for clinical trials in children's orthopaedics. Methods A modified Delphi technique was used, which involved an initial scoping survey, a two-round Delphi process and an expert panel formed of members of the British Society of Children's Orthopaedic Surgery. The survey was conducted amongst orthopaedic surgeons treating children in the United Kingdom and Ireland. Results A total of 86 clinicians contributed to both rounds of the Delphi process, scoring priorities from one (low priority) to five (high priority). Elective topics were ranked higher than those relating to trauma, with the top ten elective research questions scoring higher than the top question for trauma. Ten elective, and five trauma research priorities were identified, with the three highest ranked questions relating to the treatment of slipped capital femoral epiphysis (mean score 4.6/ 5), Perthes' disease (4.5) and bone infection (4.5). Conclusion This consensus-based research agenda will guide surgeons, academics and funders to improve the evidence in children's orthopaedic surgery and encourage the development of multicentre clinical trials. Cite this article: Bone Joint J 2018;100-B:680-4.

  8. A traffic priority language for collision-free navigation of autonomous mobile robots in dynamic environments.

    PubMed

    Bourbakis, N G

    1997-01-01

    This paper presents a generic traffic priority language, called KYKLOFORTA, used by autonomous robots for collision-free navigation in a dynamic unknown or known navigation space. In a previous work by X. Grossmman (1988), a set of traffic control rules was developed for the navigation of the robots on the lines of a two-dimensional (2-D) grid and a control center coordinated and synchronized their movements. In this work, the robots are considered autonomous: they are moving anywhere and in any direction inside the free space, and there is no need of a central control to coordinate and synchronize them. The requirements for each robot are i) visual perception, ii) range sensors, and iii) the ability of each robot to detect other moving objects in the same free navigation space, define the other objects perceived size, their velocity and their directions. Based on these assumptions, a traffic priority language is needed for each robot, making it able to decide during the navigation and avoid possible collision with other moving objects. The traffic priority language proposed here is based on a set of primitive traffic priority alphabet and rules which compose pattern of corridors for the application of the traffic priority rules.

  9. International identification of research priorities for postgraduate theses in musculoskeletal physiotherapy using a modified Delphi technique.

    PubMed

    Rushton, Alison; Moore, Ann

    2010-04-01

    Research priorities are established to identify gaps and maximise opportunities in developing an evidence base. Numerous postgraduate research theses are undertaken each year within the specialist area of musculoskeletal physiotherapy, and although some are published, greater potential for influence exists. This paper identifies international research priorities for postgraduate theses developed using a consensual Delphi process. A purposive sample included course tutors and expert clinicians nominated by Member Organisations of the International Federation of Orthopaedic Manipulative Physical Therapists (N=91). Round 1 requested >10 priorities for theses, and content analysis identified research themes. Round 2 requested participants rank the importance of each theme on a 1-5 scale, and round 3 requested ranking the importance and feasibility of the research question areas within each agreed theme. Descriptive analysis and use of Kendall's coefficient of concordance enabled interpretation of consensus. The response rate of 68% was good, identifying 23 research themes in round 1. Round 2 identified 14 research themes as important. Participant rating of the importance and feasibility of research question areas in round 3 supported 43 agreed priorities demonstrating good measurement validity. Establishing priorities provides a vision of how postgraduate theses can contribute to the developing evidence base and offer a focus for international collaboration. Copyright 2009 Elsevier Ltd. All rights reserved.

  10. Building on IUCN regional red lists to produce lists of species of conservation priority: a model with Irish bees.

    PubMed

    Fitzpatrick, Una; Murray, Tomás E; Paxton, Robert J; Brown, Mark J F

    2007-10-01

    A World Conservation Union (IUCN) regional red list is an objective assessment of regional extinction risk and is not the same as a list of conservation priority species. Recent research reveals the widespread, but incorrect, assumption that IUCN Red List categories represent a hierarchical list of priorities for conservation action. We developed a simple eight-step priority-setting process and applied it to the conservation of bees in Ireland. Our model is based on the national red list but also considers the global significance of the national population; the conservation status at global, continental, and regional levels; key biological, economic, and societal factors; and is compatible with existing conservation agreements and legislation. Throughout Ireland, almost one-third of the bee fauna is threatened (30 of 100 species), but our methodology resulted in a reduced list of only 17 priority species. We did not use the priority species list to broadly categorize species to the conservation action required; instead, we indicated the individual action required for all threatened, near-threatened, and data-deficient species on the national red list based on the IUCN's conservation-actions template file. Priority species lists will strongly influence prioritization of conservation actions at national levels, but action should not be exclusive to listed species. In addition, all species on this list will not necessarily require immediate action. Our method is transparent, reproducible, and readily applicable to other taxa and regions.

  11. Setting Healthcare Priorities at the Macro and Meso Levels: A Framework for Evaluation

    PubMed Central

    Barasa, Edwine W.; Molyneux, Sassy; English, Mike; Cleary, Susan

    2015-01-01

    Background: Priority setting in healthcare is a key determinant of health system performance. However, there is no widely accepted priority setting evaluation framework. We reviewed literature with the aim of developing and proposing a framework for the evaluation of macro and meso level healthcare priority setting practices. Methods: We systematically searched Econlit, PubMed, CINAHL, and EBSCOhost databases and supplemented this with searches in Google Scholar, relevant websites and reference lists of relevant papers. A total of 31 papers on evaluation of priority setting were identified. These were supplemented by broader theoretical literature related to evaluation of priority setting. A conceptual review of selected papers was undertaken. Results: Based on a synthesis of the selected literature, we propose an evaluative framework that requires that priority setting practices at the macro and meso levels of the health system meet the following conditions: (1) Priority setting decisions should incorporate both efficiency and equity considerations as well as the following outcomes; (a) Stakeholder satisfaction, (b) Stakeholder understanding, (c) Shifted priorities (reallocation of resources), and (d) Implementation of decisions. (2) Priority setting processes should also meet the procedural conditions of (a) Stakeholder engagement, (b) Stakeholder empowerment, (c) Transparency, (d) Use of evidence, (e) Revisions, (f) Enforcement, and (g) Being grounded on community values. Conclusion: Available frameworks for the evaluation of priority setting are mostly grounded on procedural requirements, while few have included outcome requirements. There is, however, increasing recognition of the need to incorporate both consequential and procedural considerations in priority setting practices. In this review, we adapt an integrative approach to develop and propose a framework for the evaluation of priority setting practices at the macro and meso levels that draws from these complementary schools of thought. PMID:26673332

  12. Setting Healthcare Priorities at the Macro and Meso Levels: A Framework for Evaluation.

    PubMed

    Barasa, Edwine W; Molyneux, Sassy; English, Mike; Cleary, Susan

    2015-09-16

    Priority setting in healthcare is a key determinant of health system performance. However, there is no widely accepted priority setting evaluation framework. We reviewed literature with the aim of developing and proposing a framework for the evaluation of macro and meso level healthcare priority setting practices. We systematically searched Econlit, PubMed, CINAHL, and EBSCOhost databases and supplemented this with searches in Google Scholar, relevant websites and reference lists of relevant papers. A total of 31 papers on evaluation of priority setting were identified. These were supplemented by broader theoretical literature related to evaluation of priority setting. A conceptual review of selected papers was undertaken. Based on a synthesis of the selected literature, we propose an evaluative framework that requires that priority setting practices at the macro and meso levels of the health system meet the following conditions: (1) Priority setting decisions should incorporate both efficiency and equity considerations as well as the following outcomes; (a) Stakeholder satisfaction, (b) Stakeholder understanding, (c) Shifted priorities (reallocation of resources), and (d) Implementation of decisions. (2) Priority setting processes should also meet the procedural conditions of (a) Stakeholder engagement, (b) Stakeholder empowerment, (c) Transparency, (d) Use of evidence, (e) Revisions, (f) Enforcement, and (g) Being grounded on community values. Available frameworks for the evaluation of priority setting are mostly grounded on procedural requirements, while few have included outcome requirements. There is, however, increasing recognition of the need to incorporate both consequential and procedural considerations in priority setting practices. In this review, we adapt an integrative approach to develop and propose a framework for the evaluation of priority setting practices at the macro and meso levels that draws from these complementary schools of thought. © 2015 by Kerman University of Medical Sciences.

  13. Improving effectiveness of systematic conservation planning with density data.

    PubMed

    Veloz, Samuel; Salas, Leonardo; Altman, Bob; Alexander, John; Jongsomjit, Dennis; Elliott, Nathan; Ballard, Grant

    2015-08-01

    Systematic conservation planning aims to design networks of protected areas that meet conservation goals across large landscapes. The optimal design of these conservation networks is most frequently based on the modeled habitat suitability or probability of occurrence of species, despite evidence that model predictions may not be highly correlated with species density. We hypothesized that conservation networks designed using species density distributions more efficiently conserve populations of all species considered than networks designed using probability of occurrence models. To test this hypothesis, we used the Zonation conservation prioritization algorithm to evaluate conservation network designs based on probability of occurrence versus density models for 26 land bird species in the U.S. Pacific Northwest. We assessed the efficacy of each conservation network based on predicted species densities and predicted species diversity. High-density model Zonation rankings protected more individuals per species when networks protected the highest priority 10-40% of the landscape. Compared with density-based models, the occurrence-based models protected more individuals in the lowest 50% priority areas of the landscape. The 2 approaches conserved species diversity in similar ways: predicted diversity was higher in higher priority locations in both conservation networks. We conclude that both density and probability of occurrence models can be useful for setting conservation priorities but that density-based models are best suited for identifying the highest priority areas. Developing methods to aggregate species count data from unrelated monitoring efforts and making these data widely available through ecoinformatics portals such as the Avian Knowledge Network will enable species count data to be more widely incorporated into systematic conservation planning efforts. © 2015, Society for Conservation Biology.

  14. The Professional Learning Needs and Priorities of Higher-Education-Based Teacher Educators in England, Ireland and Scotland

    ERIC Educational Resources Information Center

    Czerniawski, Gerry; Gray, Donald; MacPhail, Ann; Bain, Yvonne; Conway, Paul; Guberman, Ainat

    2018-01-01

    Against a rapidly changing policy landscape for teacher education, exacerbated by 'Brexit' in the UK, findings are presented from an electronic survey of 272 higher-education based teacher educators in England, the Republic of Ireland and Scotland about their experiences of, and priorities for, professional learning. While the data generated were…

  15. Hypertension management research priorities from patients, caregivers, and healthcare providers: A report from the Hypertension Canada Priority Setting Partnership Group.

    PubMed

    Khan, Nadia; Bacon, Simon L; Khan, Samia; Perlmutter, Sara; Gerlinsky, Carline; Dermer, Mark; Johnson, Lonni; Alves, Finderson; McLean, Donna; Laupacis, Andreas; Pui, Mandy; Berg, Angelique; Flowitt, Felicia

    2017-11-01

    Patient- and stakeholder-oriented research is vital to improving the relevance of research. The authors aimed to identify the 10 most important research priorities of patients, caregivers, and healthcare providers (family physicians, nurses, nurse practitioners, pharmacists, and dietitians) for hypertension management. Using the James Lind Alliance approach, a national web-based survey asked patients, caregivers, and care providers to submit their unanswered questions on hypertension management. Questions already answered from randomized controlled trial evidence were removed. A priority setting process of patient, caregiver, and healthcare providers then ranked the final top 10 research priorities in an in-person meeting. There were 386 respondents who submitted 598 questions after exclusions. Of the respondents, 78% were patients or caregivers, 29% lived in rural areas, 78% were aged 50 to 80 years, and 75% were women. The 598 questions were distilled to 42 unique questions and from this list, the top 10 research questions prioritized included determining the combinations of healthy lifestyle modifications to reduce the need for antihypertensive medications, stress management interventions, evaluating treatment strategies based on out-of-office blood pressure compared with conventional (office) blood pressure, education tools and technologies to improve patient motivation and health behavior change, management strategies for ethnic groups, evaluating natural and alternative treatments, and the optimal role of different healthcare providers and caregivers in supporting patients with hypertension. These priorities can be used to guide clinicians, researchers, and funding bodies on areas that are a high priority for hypertension management research for patients, caregivers, and healthcare providers. This also highlights priority areas for improved knowledge translation and delivering patient-centered care. ©2017 Wiley Periodicals, Inc.

  16. Advancing Evidence-Based Assessment in School Mental Health: Key Priorities for an Applied Research Agenda.

    PubMed

    Arora, Prerna G; Connors, Elizabeth H; George, Melissa W; Lyon, Aaron R; Wolk, Courtney B; Weist, Mark D

    2016-12-01

    Evidence-based assessment (EBA) is a critically important aspect of delivering high-quality, school-based mental health care for youth. However, research in this area is limited and additional applied research on how best to support the implementation of EBA in school mental health (SMH) is needed. Accordingly, this manuscript seeks to facilitate the advancement of research on EBA in SMH by reviewing relevant literature on EBA implementation in schools and providing recommendations for key research priorities. Given the limited number of published studies available, findings from child and adolescent mental health and implementation science research are also included to inform a robust and comprehensive research agenda on this topic. Based on this literature review, five priorities for research on EBA in SMH are outlined: (1) effective identification of assessment targets, (2) appropriate selection of assessment measures, (3) investigation of organizational readiness for EBA, (4) study of implementation support for EBA, and (5) promotion of EBA data integration and use. Each priority area includes recommended directions for future research. A comprehensive and robust research agenda is warranted to build the science and practice of implementing EBA in SMH. Specific directions for this agenda are offered.

  17. The World Starts With Me: using intervention mapping for the systematic adaptation and transfer of school-based sexuality education from Uganda to Indonesia.

    PubMed

    Leerlooijer, Joanne N; Ruiter, Robert A C; Reinders, Jo; Darwisyah, Wati; Kok, Gerjo; Bartholomew, L Kay

    2011-06-01

    Evidence-based health promotion programmes, including HIV/AIDS prevention and sexuality education programmes, are often transferred to other cultures, priority groups and implementation settings. Challenges in this process include the identification of retaining core elements that relate to the programme's effectiveness while making changes that enhances acceptance in the new context and for the new priority group. This paper describes the use of a systematic approach to programme adaptation using a case study as an example. Intervention Mapping, a protocol for the development of evidence-based behaviour change interventions, was used to adapt the comprehensive school-based sexuality education programme 'The World Starts With Me'. The programme was developed for a priority population in Uganda and adapted to a programme for Indonesian secondary school students. The approach helped to systematically address the complexity and challenges of programme adaptation and to find a balance between preservation of essential programme elements (i.e. logic models) that may be crucial to the programme's effectiveness, including key objectives and theoretical behaviour change methods, and the adaptation of the programme to be acceptable to the new priority group and the programme implementers.

  18. Representation and Integration of Scientific Information

    NASA Technical Reports Server (NTRS)

    1998-01-01

    The objective of this Joint Research Interchange with NASA-Ames was to investigate how the Tsimmis technology could be used to represent and integrate scientific information. The main goal of the Tsimmis project is to allow a decision maker to find information of interest from such sources, fuse it, and process it (e.g., summarize it, visualize it, discover trends). Another important goal is the easy incorporation of new sources, as well the ability to deal with sources whose structure or services evolve. During the Interchange we had research meetings approximately every month or two. The funds provided by NASA supported work that lead to the following two papers: Fusion Queries over Internet Databases; Efficient Query Subscription Processing in a Multicast Environment.

  19. Modelling and temporal performances evaluation of networked control systems using (max, +) algebra

    NASA Astrophysics Data System (ADS)

    Ammour, R.; Amari, S.

    2015-01-01

    In this paper, we address the problem of temporal performances evaluation of producer/consumer networked control systems. The aim is to develop a formal method for evaluating the response time of this type of control systems. Our approach consists on modelling, using Petri nets classes, the behaviour of the whole architecture including the switches that support multicast communications used by this protocol. (max, +) algebra formalism is then exploited to obtain analytical formulas of the response time and the maximal and minimal bounds. The main novelty is that our approach takes into account all delays experienced at the different stages of networked automation systems. Finally, we show how to apply the obtained results through an example of networked control system.

  20. Paying more for faster care? Individuals' attitude toward price-based priority access in health care.

    PubMed

    Benning, Tim M; Dellaert, Benedict G C

    2013-05-01

    Increased competition in the health care sector has led hospitals and other health care institutions to experiment with new access allocation policies that move away from traditional expert based allocation of care to price-based priority access (i.e., the option to pay more for faster care). To date, little is known about individuals' attitude toward price-based priority access and the evaluation process underlying this attitude. This paper addresses the role of individuals' evaluations of collective health outcomes as an important driver of their attitude toward (price-based) allocation policies in health care. The authors investigate how individuals evaluate price-based priority access by means of scenario-based survey data collected in a representative sample from the Dutch population (N = 1464). They find that (a) offering individuals the opportunity to pay for faster care negatively affects their evaluations of both the total and distributional collective health outcome achieved, (b) however, when health care supply is not restricted (i.e., when treatment can be offered outside versus within the regular working hours of the hospital) offering price-based priority access affects total collective health outcome evaluations positively instead of negatively, but it does not change distributional collective health outcome evaluations. Furthermore, (c) the type of health care treatment (i.e., life saving liver transplantation treatment vs. life improving cosmetic ear correction treatment - priced at the same level to the individual) moderates the effect of collective health outcome evaluations on individuals' attitude toward allocation policies. For policy makers and hospital managers the results presented in this article are helpful because they provide a better understanding of what drives individuals' preferences for health care allocation policies. In particular, the results show that policies based on the "paying more for faster care" principle are more attractive to the general public when treatment takes place outside the regular working hours of a hospital. Copyright © 2013 Elsevier Ltd. All rights reserved.

  1. Global priorities for conservation across multiple dimensions of mammalian diversity

    PubMed Central

    Graham, Catherine H.; Costa, Gabriel C.; Hedges, S. Blair; Penone, Caterina; Radeloff, Volker C.; Rondinini, Carlo; Davidson, Ana D.

    2017-01-01

    Conservation priorities that are based on species distribution, endemism, and vulnerability may underrepresent biologically unique species as well as their functional roles and evolutionary histories. To ensure that priorities are biologically comprehensive, multiple dimensions of diversity must be considered. Further, understanding how the different dimensions relate to one another spatially is important for conservation prioritization, but the relationship remains poorly understood. Here, we use spatial conservation planning to (i) identify and compare priority regions for global mammal conservation across three key dimensions of biodiversity—taxonomic, phylogenetic, and traits—and (ii) determine the overlap of these regions with the locations of threatened species and existing protected areas. We show that priority areas for mammal conservation exhibit low overlap across the three dimensions, highlighting the need for an integrative approach for biodiversity conservation. Additionally, currently protected areas poorly represent the three dimensions of mammalian biodiversity. We identify areas of high conservation priority among and across the dimensions that should receive special attention for expanding the global protected area network. These high-priority areas, combined with areas of high priority for other taxonomic groups and with social, economic, and political considerations, provide a biological foundation for future conservation planning efforts. PMID:28674013

  2. Global priorities for conservation across multiple dimensions of mammalian diversity.

    PubMed

    Brum, Fernanda T; Graham, Catherine H; Costa, Gabriel C; Hedges, S Blair; Penone, Caterina; Radeloff, Volker C; Rondinini, Carlo; Loyola, Rafael; Davidson, Ana D

    2017-07-18

    Conservation priorities that are based on species distribution, endemism, and vulnerability may underrepresent biologically unique species as well as their functional roles and evolutionary histories. To ensure that priorities are biologically comprehensive, multiple dimensions of diversity must be considered. Further, understanding how the different dimensions relate to one another spatially is important for conservation prioritization, but the relationship remains poorly understood. Here, we use spatial conservation planning to ( i ) identify and compare priority regions for global mammal conservation across three key dimensions of biodiversity-taxonomic, phylogenetic, and traits-and ( ii ) determine the overlap of these regions with the locations of threatened species and existing protected areas. We show that priority areas for mammal conservation exhibit low overlap across the three dimensions, highlighting the need for an integrative approach for biodiversity conservation. Additionally, currently protected areas poorly represent the three dimensions of mammalian biodiversity. We identify areas of high conservation priority among and across the dimensions that should receive special attention for expanding the global protected area network. These high-priority areas, combined with areas of high priority for other taxonomic groups and with social, economic, and political considerations, provide a biological foundation for future conservation planning efforts.

  3. Human-tracking strategies for a six-legged rescue robot based on distance and view

    NASA Astrophysics Data System (ADS)

    Pan, Yang; Gao, Feng; Qi, Chenkun; Chai, Xun

    2016-03-01

    Human tracking is an important issue for intelligent robotic control and can be used in many scenarios, such as robotic services and human-robot cooperation. Most of current human-tracking methods are targeted for mobile/tracked robots, but few of them can be used for legged robots. Two novel human-tracking strategies, view priority strategy and distance priority strategy, are proposed specially for legged robots, which enable them to track humans in various complex terrains. View priority strategy focuses on keeping humans in its view angle arrange with priority, while its counterpart, distance priority strategy, focuses on keeping human at a reasonable distance with priority. To evaluate these strategies, two indexes(average and minimum tracking capability) are defined. With the help of these indexes, the view priority strategy shows advantages compared with distance priority strategy. The optimization is done in terms of these indexes, which let the robot has maximum tracking capability. The simulation results show that the robot can track humans with different curves like square, circular, sine and screw paths. Two novel control strategies are proposed which specially concerning legged robot characteristics to solve human tracking problems more efficiently in rescue circumstances.

  4. Generalized priority-queue network dynamics: Impact of team and hierarchy

    NASA Astrophysics Data System (ADS)

    Cho, Won-Kuk; Min, Byungjoon; Goh, K.-I.; Kim, I.-M.

    2010-06-01

    We study the effect of team and hierarchy on the waiting-time dynamics of priority-queue networks. To this end, we introduce generalized priority-queue network models incorporating interaction rules based on team-execution and hierarchy in decision making, respectively. It is numerically found that the waiting-time distribution exhibits a power law for long waiting times in both cases, yet with different exponents depending on the team size and the position of queue nodes in the hierarchy, respectively. The observed power-law behaviors have in many cases a corresponding single or pairwise-interacting queue dynamics, suggesting that the pairwise interaction may constitute a major dynamic consequence in the priority-queue networks. It is also found that the reciprocity of influence is a relevant factor for the priority-queue network dynamics.

  5. PWFQ: a priority-based weighted fair queueing algorithm for the downstream transmission of EPON

    NASA Astrophysics Data System (ADS)

    Xu, Sunjuan; Ye, Jiajun; Zou, Junni

    2005-11-01

    In the downstream direction of EPON, all ethernet frames share one downlink channel from the OLT to destination ONUs. To guarantee differentiated services, a scheduling algorithm is needed to solve the link-sharing issue. In this paper, we first review the classical WFQ algorithm and point out the shortcomings existing in the fair queueing principle of WFQ algorithm for EPON. Then we propose a novel scheduling algorithm called Priority-based WFQ (PWFQ) algorithm which distributes bandwidth based on priority. PWFQ algorithm can guarantee the quality of real-time services whether under light load or under heavy load. Simulation results also show that PWFQ algorithm not only can improve delay performance of real-time services, but can also meet the worst-case delay bound requirements.

  6. Setting conservation priorities.

    PubMed

    Wilson, Kerrie A; Carwardine, Josie; Possingham, Hugh P

    2009-04-01

    A generic framework for setting conservation priorities based on the principles of classic decision theory is provided. This framework encapsulates the key elements of any problem, including the objective, the constraints, and knowledge of the system. Within the context of this framework the broad array of approaches for setting conservation priorities are reviewed. While some approaches prioritize assets or locations for conservation investment, it is concluded here that prioritization is incomplete without consideration of the conservation actions required to conserve the assets at particular locations. The challenges associated with prioritizing investments through time in the face of threats (and also spatially and temporally heterogeneous costs) can be aided by proper problem definition. Using the authors' general framework for setting conservation priorities, multiple criteria can be rationally integrated and where, how, and when to invest conservation resources can be scheduled. Trade-offs are unavoidable in priority setting when there are multiple considerations, and budgets are almost always finite. The authors discuss how trade-offs, risks, uncertainty, feedbacks, and learning can be explicitly evaluated within their generic framework for setting conservation priorities. Finally, they suggest ways that current priority-setting approaches may be improved.

  7. Cultural bases for self-evaluation: seeing oneself positively in different cultural contexts.

    PubMed

    Becker, Maja; Vignoles, Vivian L; Owe, Ellinor; Easterbrook, Matthew J; Brown, Rupert; Smith, Peter B; Bond, Michael Harris; Regalia, Camillo; Manzi, Claudia; Brambilla, Maria; Aldhafri, Said; González, Roberto; Carrasco, Diego; Paz Cadena, Maria; Lay, Siugmin; Schweiger Gallo, Inge; Torres, Ana; Camino, Leoncio; Özgen, Emre; Güner, Ülkü E; Yamakoğlu, Nil; Silveira Lemos, Flávia Cristina; Trujillo, Elvia Vargas; Balanta, Paola; Macapagal, Ma Elizabeth J; Cristina Ferreira, M; Herman, Ginette; de Sauvage, Isabelle; Bourguignon, David; Wang, Qian; Fülöp, Márta; Harb, Charles; Chybicka, Aneta; Mekonnen, Kassahun Habtamu; Martin, Mariana; Nizharadze, George; Gavreliuc, Alin; Buitendach, Johanna; Valk, Aune; Koller, Silvia H

    2014-05-01

    Several theories propose that self-esteem, or positive self-regard, results from fulfilling the value priorities of one's surrounding culture. Yet, surprisingly little evidence exists for this assertion, and theories differ about whether individuals must personally endorse the value priorities involved. We compared the influence of four bases for self-evaluation (controlling one's life, doing one's duty, benefitting others, achieving social status) among 4,852 adolescents across 20 cultural samples, using an implicit, within-person measurement technique to avoid cultural response biases. Cross-sectional and longitudinal analyses showed that participants generally derived feelings of self-esteem from all four bases, but especially from those that were most consistent with the value priorities of others in their cultural context. Multilevel analyses confirmed that the bases of positive self-regard are sustained collectively: They are predictably moderated by culturally normative values but show little systematic variation with personally endorsed values.

  8. Effects of gaps in priorities between ideal and real lives on psychological burnout among academic faculty members at a medical university in Japan: a cross-sectional study.

    PubMed

    Chatani, Yuki; Nomura, Kyoko; Horie, Saki; Takemoto, Keisuke; Takeuchi, Masumi; Sasamori, Yukifumi; Takenoshita, Shinichi; Murakami, Aya; Hiraike, Haruko; Okinaga, Hiroko; Smith, Derek

    2017-04-04

    Accumulating evidence from medical workforce research indicates that poor work/life balance and increased work/home conflict induce psychological distress. In this study we aim to examine the existence of a priority gap between ideal and real lives, and its association with psychological burnout among academic professionals. This cross-sectional survey, conducted in 2014, included faculty members (228 men, 102 women) at a single medical university in Tokyo, Japan. The outcome of interest was psychological burnout, measured with a validated inventory. Discordance between ideal- and real-life priorities, based on participants' responses (work, family, individual life, combinations thereof), was defined as a priority gap. The majority (64%) of participants chose "work" as the greatest priority in real life, but only 28% chose "work" as the greatest priority in their conception of an ideal life. Priority gaps were identified in 59.5% of respondents. A stepwise multivariable general linear model demonstrated that burnout scores were associated positively with respondents' current position (P < 0.0018) and the presence of a priority gap (P < 0.0001), and negatively with the presence of social support (P < 0.0001). Among participants reporting priority gaps, burnout scores were significantly lower in those with children than in those with no children (P interaction  = 0.011); no such trend was observed in participants with no priority gap. A gap in priorities between an ideal and real life was associated with an increased risk of burnout, and the presence of children, which is a type of "family" social support, had a mitigating effect on burnout among those reporting priority gaps.

  9. 7 CFR 4279.155 - Loan priorities.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... natural resource value-added product (2 points). (iii) Occupations. The priority score for occupations... natural disaster or experiencing fundamental structural changes in its economic base (5 points). (iv... for the following: (A) Business that offers high value, specialized products and services that command...

  10. 7 CFR 4279.155 - Loan priorities.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... natural resource value-added product (2 points). (iii) Occupations. The priority score for occupations... natural disaster or experiencing fundamental structural changes in its economic base (5 points). (iv... for the following: (A) Business that offers high value, specialized products and services that command...

  11. 7 CFR 4279.155 - Loan priorities.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... natural resource value-added product (2 points). (iii) Occupations. The priority score for occupations... natural disaster or experiencing fundamental structural changes in its economic base (5 points). (iv... for the following: (A) Business that offers high value, specialized products and services that command...

  12. 7 CFR 4279.155 - Loan priorities.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... natural resource value-added product (2 points). (iii) Occupations. The priority score for occupations... natural disaster or experiencing fundamental structural changes in its economic base (5 points). (iv... for the following: (A) Business that offers high value, specialized products and services that command...

  13. Region 6's 2016 Strategic Plan and 2015 Accomplishment Report

    EPA Pesticide Factsheets

    The EPA Region 6 Strategic Plan highlights the goals we have set out to accomplish in 2016 based on each of our priorities. areas. Our Accomplishment Report summarizes our work in meeting these priorities during the prior year.

  14. A lock-free priority queue design based on multi-dimensional linked lists

    DOE PAGES

    Dechev, Damian; Zhang, Deli

    2015-04-03

    The throughput of concurrent priority queues is pivotal to multiprocessor applications such as discrete event simulation, best-first search and task scheduling. Existing lock-free priority queues are mostly based on skiplists, which probabilistically create shortcuts in an ordered list for fast insertion of elements. The use of skiplists eliminates the need of global rebalancing in balanced search trees and ensures logarithmic sequential search time on average, but the worst-case performance is linear with respect to the input size. In this paper, we propose a quiescently consistent lock-free priority queue based on a multi-dimensional list that guarantees worst-case search time of O(logN)more » for key universe of size N. The novel multi-dimensional list (MDList) is composed of nodes that contain multiple links to child nodes arranged by their dimensionality. The insertion operation works by first injectively mapping the scalar key to a high-dimensional vector, then uniquely locating the target position by using the vector as coordinates. Nodes in MDList are ordered by their coordinate prefixes and the ordering property of the data structure is readily maintained during insertion without rebalancing nor randomization. Furthermore, in our experimental evaluation using a micro-benchmark, our priority queue achieves an average of 50% speedup over the state of the art approaches under high concurrency.« less

  15. A lock-free priority queue design based on multi-dimensional linked lists

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

    Dechev, Damian; Zhang, Deli

    The throughput of concurrent priority queues is pivotal to multiprocessor applications such as discrete event simulation, best-first search and task scheduling. Existing lock-free priority queues are mostly based on skiplists, which probabilistically create shortcuts in an ordered list for fast insertion of elements. The use of skiplists eliminates the need of global rebalancing in balanced search trees and ensures logarithmic sequential search time on average, but the worst-case performance is linear with respect to the input size. In this paper, we propose a quiescently consistent lock-free priority queue based on a multi-dimensional list that guarantees worst-case search time of O(logN)more » for key universe of size N. The novel multi-dimensional list (MDList) is composed of nodes that contain multiple links to child nodes arranged by their dimensionality. The insertion operation works by first injectively mapping the scalar key to a high-dimensional vector, then uniquely locating the target position by using the vector as coordinates. Nodes in MDList are ordered by their coordinate prefixes and the ordering property of the data structure is readily maintained during insertion without rebalancing nor randomization. Furthermore, in our experimental evaluation using a micro-benchmark, our priority queue achieves an average of 50% speedup over the state of the art approaches under high concurrency.« less

  16. The Starlite Project - Prototyping Real-Time Software.

    DTIC Science & Technology

    1992-11-01

    by ONR under contract ledge of transactions and a temporal data model. A N00014-91-J-l 102, by DOE, and by NOSC. multiversion data object is one...environment. Section 4 presents experimentations of priority-based synchronization algorithms and multiversion data objects using the prototyping environment...priority-based .yn- chronization algorithms and between a multiversion database and its corresponding single- version database, through the sensitivity

  17. Performance Evaluation of Telemedicine System based on multicasting over Heterogeneous Network.

    PubMed

    Yun, H Y; Yoo, S K; Kim, D K; Rim Kim, Sung

    2005-01-01

    For appropriate diagnosis, medical image such as high quality image of patient's affected part and vital signal, patient information, and teleconferencing data for communication between specialists will be transmitted. After connecting patient and specialist the center, sender acquires patient data and transmits to the center through TCP/IP protocol. Data that is transmitted to center is retransmitted to each specialist side that accomplish connection after being copied according to listener's number from transmission buffer. At transmission of medical information data in network, transmission delay and loss occur by the change of buffer size, packet size, number of user and kind of networks. As there lies the biggest delay possibility in ADSL, buffer Size should be established by 1Mbytes first to minimize transmission regionalism and each packet's size must be set accordingly to MTU Size in order to improve network efficiency by maximum. Also, listener's number should be limited by less than 6 people. Data transmission consisted smoothly all in experiment result in common use network- ADSL, VDSL, WLAN, LAN-. But, possibility of delay appeared most greatly in ADSL that has the most confined bandwidth. To minimize the possibility of delay, some adjustment is needed such as buffer size, number of receiver, packet size.

  18. Multi-casting approach for vascular networks in cellularized hydrogels.

    PubMed

    Justin, Alexander W; Brooks, Roger A; Markaki, Athina E

    2016-12-01

    Vascularization is essential for living tissue and remains a major challenge in the field of tissue engineering. A lack of a perfusable channel network within a large and densely populated tissue engineered construct leads to necrotic core formation, preventing fabrication of functional tissues and organs. We report a new method for producing a hierarchical, three-dimensional (3D) and perfusable vasculature in a large, cellularized fibrin hydrogel. Bifurcating channels, varying in size from 1 mm to 200-250 µm, are formed using a novel process in which we convert a 3D printed thermoplastic material into a gelatin network template, by way of an intermediate alginate hydrogel. This enables a CAD-based model design, which is highly customizable, reproducible, and which can yield highly complex architectures, to be made into a removable material, which can be used in cellular environments. Our approach yields constructs with a uniform and high density of cells in the bulk, made from bioactive collagen and fibrin hydrogels. Using standard cell staining and immuno-histochemistry techniques, we showed good cell seeding and the presence of tight junctions between channel endothelial cells, and high cell viability and cell spreading in the bulk hydrogel. © 2016 The Authors.

  19. Evaluation and Selection of Best Priority Sequencing Rule in Job Shop Scheduling using Hybrid MCDM Technique

    NASA Astrophysics Data System (ADS)

    Kiran Kumar, Kalla; Nagaraju, Dega; Gayathri, S.; Narayanan, S.

    2017-05-01

    Priority Sequencing Rules provide the guidance for the order in which the jobs are to be processed at a workstation. The application of different priority rules in job shop scheduling gives different order of scheduling. More experimentation needs to be conducted before a final choice is made to know the best priority sequencing rule. Hence, a comprehensive method of selecting the right choice is essential in managerial decision making perspective. This paper considers seven different priority sequencing rules in job shop scheduling. For evaluation and selection of the best priority sequencing rule, a set of eight criteria are considered. The aim of this work is to demonstrate the methodology of evaluating and selecting the best priority sequencing rule by using hybrid multi criteria decision making technique (MCDM), i.e., analytical hierarchy process (AHP) with technique for order preference by similarity to ideal solution (TOPSIS). The criteria weights are calculated by using AHP whereas the relative closeness values of all priority sequencing rules are computed based on TOPSIS with the help of data acquired from the shop floor of a manufacturing firm. Finally, from the findings of this work, the priority sequencing rules are ranked from most important to least important. The comprehensive methodology presented in this paper is very much essential for the management of a workstation to choose the best priority sequencing rule among the available alternatives for processing the jobs with maximum benefit.

  20. Priorities for research in child maltreatment, intimate partner violence and resilience to violence exposures: results of an international Delphi consensus development process.

    PubMed

    Wathen, C Nadine; MacGregor, Jennifer C D; Hammerton, Joanne; Coben, Jeffrey H; Herrman, Helen; Stewart, Donna E; MacMillan, Harriet L

    2012-08-21

    Intimate partner violence (IPV) and child maltreatment (CM) are major global public health problems. The Preventing Violence Across the Lifespan (PreVAiL) Research Network, an international group of over 60 researchers and national and international knowledge-user partners in CM and IPV, sought to identify evidence-based research priorities in IPV and CM, with a focus on resilience, using a modified Delphi consensus development process. Review of existing empirical evidence, PreVAiL documents and team discussion identified a starting list of 20 priorities in the following categories: resilience to violence exposure (RES), CM, and IPV, as well as priorities that cross-cut the content areas (CC), and others specific to research methodologies (RM) in violence research. PreVAiL members (N = 47) completed two online survey rounds, and one round of discussions via three teleconference calls to rate, rank and refine research priorities. Research priorities were: to examine key elements of promising or successful programmes in RES/CM/IPV to build intervention pilot work; CC: to integrate violence questions into national and international surveys, and RM: to investigate methods for collecting and collating datasets to link data and to conduct pooled, meta and sub-group analyses to identify promising interventions for particular groups. These evidence-based research priorities, developed by an international team of violence, gender and mental health researchers and knowledge-user partners, are of relevance for prevention and resilience-oriented research in the areas of IPV and CM.

  1. The development of a national nutrition and mental health research agenda with comparison of priorities among diverse stakeholders.

    PubMed

    Davison, Karen M; D'Andreamatteo, Carla; Mitchell, Scott; Vanderkooy, Pat

    2017-03-01

    To develop a national nutrition and mental health research agenda based on the engagement of diverse stakeholders and to assess research priorities by stakeholder groups. A staged, integrated and participatory initiative was implemented to structure a national nutrition and mental health research agenda that included: (i) national stakeholder consultations to prioritize research questions; (ii) a workshop involving national representatives from research, policy and practice to further define priorities; (iii) triangulation of data to formulate the agenda; and (iv) test hypotheses about stakeholder influences on decision making. Canada. Diverse stakeholders including researchers, academics, administrators, service providers, policy makers, practitioners, non-profit, industry and funding agency representatives, front-line workers, individuals with lived experience of a mental health condition and those who provide care for them. This first-of-its-kind research priority-setting initiative showed points of agreement among diverse stakeholders (n 899) on research priorities aimed at service provision; however, respondents with lived experience of a mental health condition (themselves or a family member) placed emphasis on prevention and mental health promotion-based research. The final integrated agenda identified four research priorities, including programmes and services, service provider roles, the determinants of health and knowledge translation and exchange. These research priorities aim to identify effective models of care, enhance collaboration, inform policy makers and foster knowledge dissemination. Since a predictor of research uptake is the involvement of relevant stakeholders, a sustained and deliberate effort must continue to engage collaboration that will lead to the optimization of nutrition and mental health-related outcomes.

  2. Priorities for research in child maltreatment, intimate partner violence and resilience to violence exposures: results of an international Delphi consensus development process

    PubMed Central

    2012-01-01

    Background Intimate partner violence (IPV) and child maltreatment (CM) are major global public health problems. The Preventing Violence Across the Lifespan (PreVAiL) Research Network, an international group of over 60 researchers and national and international knowledge-user partners in CM and IPV, sought to identify evidence-based research priorities in IPV and CM, with a focus on resilience, using a modified Delphi consensus development process. Methods Review of existing empirical evidence, PreVAiL documents and team discussion identified a starting list of 20 priorities in the following categories: resilience to violence exposure (RES), CM, and IPV, as well as priorities that cross-cut the content areas (CC), and others specific to research methodologies (RM) in violence research. PreVAiL members (N = 47) completed two online survey rounds, and one round of discussions via three teleconference calls to rate, rank and refine research priorities. Results Research priorities were: to examine key elements of promising or successful programmes in RES/CM/IPV to build intervention pilot work; CC: to integrate violence questions into national and international surveys, and RM: to investigate methods for collecting and collating datasets to link data and to conduct pooled, meta and sub-group analyses to identify promising interventions for particular groups. Conclusions These evidence-based research priorities, developed by an international team of violence, gender and mental health researchers and knowledge-user partners, are of relevance for prevention and resilience-oriented research in the areas of IPV and CM. PMID:22908894

  3. Research priorities for adolescent health in low- and middle-income countries: A mixed-methods synthesis of two separate exercises

    PubMed Central

    Nagata, Jason M; Hathi, Sejal; Ferguson, B Jane; Hindin, Michele J; Yoshida, Sachiyo; Ross, David A

    2018-01-01

    Background In order to clarify priorities and stimulate research in adolescent health in low- and middle-income countries (LMICs), the World Health Organization (WHO) conducted two priority-setting exercises based on the Child Health and Nutrition Research Initiative (CHNRI) methodology related to 1) adolescent sexual and reproductive health and 2) eight areas of adolescent health including communicable diseases prevention and management, injuries and violence, mental health, non-communicable diseases management, nutrition, physical activity, substance use, and health policy. Although the CHNRI methodology has been utilized in over 50 separate research priority setting exercises, none have qualitatively synthesized the ultimate findings across studies. The purpose of this study was to conduct a mixed-method synthesis of two research priority-setting exercises for adolescent health in LMICs based on the CHNRI methodology and to situate the priority questions within the current global health agenda. Methods All of the 116 top-ranked questions presented in each exercise were analyzed by two independent reviewers. Word clouds were generated based on keywords from the top-ranked questions. Questions were coded and content analysis was conducted based on type of delivery platform, vulnerable populations, and the Survive, Thrive, and Transform framework from the United Nations Global Strategy for Women’s, Children’s, and Adolescents’ Health, 2016-2030. Findings Within the 53 top-ranked intervention-related questions that specified a delivery platform, the platforms specified were schools (n = 17), primary care (n = 12), community (n = 11), parenting (n = 6), virtual media (n = 5), and peers (n = 2). Twenty questions specifically focused on vulnerable adolescents, including those living with HIV, tuberculosis, mental illness, or neurodevelopmental disorders; victims of gender-based violence; refugees; young persons who inject drugs; sex workers; slum dwellers; out-of-school youth; and youth in armed conflict. A majority of the top-ranked questions (108/116) aligned with one or a combination of the Survive (n = 39), Thrive (n = 67), and Transform (n = 28) agendas. Conclusions This study advances the CHNRI methodology by conducting the first mixed-methods synthesis of multiple research priority-setting exercises by analyzing keywords (using word clouds) and themes (using content analysis). PMID:29497507

  4. Priority in Process Algebras

    NASA Technical Reports Server (NTRS)

    Cleaveland, Rance; Luettgen, Gerald; Natarajan, V.

    1999-01-01

    This paper surveys the semantic ramifications of extending traditional process algebras with notions of priority that allow for some transitions to be given precedence over others. These enriched formalisms allow one to model system features such as interrupts, prioritized choice, or real-time behavior. Approaches to priority in process algebras can be classified according to whether the induced notion of preemption on transitions is global or local and whether priorities are static or dynamic. Early work in the area concentrated on global pre-emption and static priorities and led to formalisms for modeling interrupts and aspects of real-time, such as maximal progress, in centralized computing environments. More recent research has investigated localized notions of pre-emption in which the distribution of systems is taken into account, as well as dynamic priority approaches, i.e., those where priority values may change as systems evolve. The latter allows one to model behavioral phenomena such as scheduling algorithms and also enables the efficient encoding of real-time semantics. Technically, this paper studies the different models of priorities by presenting extensions of Milner's Calculus of Communicating Systems (CCS) with static and dynamic priority as well as with notions of global and local pre- emption. In each case the operational semantics of CCS is modified appropriately, behavioral theories based on strong and weak bisimulation are given, and related approaches for different process-algebraic settings are discussed.

  5. Monitoring Natural World Heritage Sites: optimization of the monitoring system in Bogda with GIS-based multi-criteria decision analysis.

    PubMed

    Wang, Zhaoguo; Du, Xishihui

    2016-07-01

    Natural World Heritage Sites (NWHSs) are invaluable treasure due to the uniqueness of each site. Proper monitoring and management can guarantee their protection from multiple threats. In this study, geographic information system (GIS)-based multi-criteria decision analysis (GIS-MCDA) was used to assess criteria layers acquired from the data available in the literature. A conceptual model for determining the priority area for monitoring in Bogda, China, was created based on outstanding universal values (OUV) and expert knowledge. Weights were assigned to each layer using the analytic hierarchy process (AHP) based on group decisions, encompassing three experts: one being a heritage site expert, another a forest ranger, and the other a heritage site manager. Subsequently, evaluation layers and constraint layers were used to generate a priority map and to determine the feasibility of monitoring in Bogda. Finally, a monitoring suitability map of Bogda was obtained by referencing priority and feasibility maps.The high-priority monitoring area is located in the montane forest belt, which exhibits high biodiversity and is the main tourist area of Bogda. The northern buffer zone of Bogda comprises the concentrated feasible monitoring areas, and the area closest to roads and monitoring facilities is highly feasible for NWHS monitoring. The suitability of an area in terms of monitoring is largely determined by the monitoring priority in that particular area. The majority of planned monitoring facilities are well distributed in both suitable and less suitable areas. Analysis results indicate that the protection of Bogda will be more scientifically based due to its effective and all-around planned monitoring system proposed by the declaration text of Xinjiang Tianshan, which is the essential file submitted to World Heritage Centre to inscribe as a NWHS.

  6. Optical/IR from ground

    NASA Technical Reports Server (NTRS)

    Strom, Stephen; Sargent, Wallace L. W.; Wolff, Sidney; Ahearn, Michael F.; Angel, J. Roger; Beckwith, Steven V. W.; Carney, Bruce W.; Conti, Peter S.; Edwards, Suzan; Grasdalen, Gary

    1991-01-01

    Optical/infrared (O/IR) astronomy in the 1990's is reviewed. The following subject areas are included: research environment; science opportunities; technical development of the 1980's and opportunities for the 1990's; and ground-based O/IR astronomy outside the U.S. Recommendations are presented for: (1) large scale programs (Priority 1: a coordinated program for large O/IR telescopes); (2) medium scale programs (Priority 1: a coordinated program for high angular resolution; Priority 2: a new generation of 4-m class telescopes); (3) small scale programs (Priority 1: near-IR and optical all-sky surveys; Priority 2: a National Astrometric Facility); and (4) infrastructure issues (develop, purchase, and distribute optical CCDs and infrared arrays; a program to support large optics technology; a new generation of large filled aperture telescopes; a program to archive and disseminate astronomical databases; and a program for training new instrumentalists)

  7. 15 CFR 700.18 - Limitations on placing rated orders.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... transportation (Department of Transportation); (v) Water resources (Department of Defense/U.S. Army Corps of... (Continued) BUREAU OF INDUSTRY AND SECURITY, DEPARTMENT OF COMMERCE NATIONAL SECURITY INDUSTRIAL BASE REGULATIONS DEFENSE PRIORITIES AND ALLOCATIONS SYSTEM Industrial Priorities § 700.18 Limitations on placing...

  8. 15 CFR 700.18 - Limitations on placing rated orders.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... transportation (Department of Transportation); (v) Water resources (Department of Defense/U.S. Army Corps of... (Continued) BUREAU OF INDUSTRY AND SECURITY, DEPARTMENT OF COMMERCE NATIONAL SECURITY INDUSTRIAL BASE REGULATIONS DEFENSE PRIORITIES AND ALLOCATIONS SYSTEM Industrial Priorities § 700.18 Limitations on placing...

  9. 15 CFR 700.18 - Limitations on placing rated orders.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... transportation (Department of Transportation); (v) Water resources (Department of Defense/U.S. Army Corps of... (Continued) BUREAU OF INDUSTRY AND SECURITY, DEPARTMENT OF COMMERCE NATIONAL SECURITY INDUSTRIAL BASE REGULATIONS DEFENSE PRIORITIES AND ALLOCATIONS SYSTEM Industrial Priorities § 700.18 Limitations on placing...

  10. Centers for Water Research on National Priorities Related to a Systems View of Nutrient Management Kick-off Meeting

    EPA Pesticide Factsheets

    At this meeting, grantees from Centers for Water Research on National Priorities Related to a Systems View of Nutrient Management and Sustainable Chesapeake: A Community-Based Approach to Stormwater Management Using Green Infrastructure

  11. 15 CFR 700.51 - Requests for priority rating authority.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... (Continued) BUREAU OF INDUSTRY AND SECURITY, DEPARTMENT OF COMMERCE NATIONAL SECURITY INDUSTRIAL BASE... authorized include: (1) Production or construction equipment; (2) Computers when not used as production items... construction equipment. (1) A request for priority rating authority for production or construction equipment...

  12. 7 CFR 662.4 - Regional Equity implementation procedure.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Section 662.4 Agriculture Regulations of the Department of Agriculture (Continued) NATURAL RESOURCES... through a merit-based, natural resource focused allocation process as determined by the Chief. (b... priorities; (B) Historic trends in program interest; and (C) State priority natural resource concerns. (ii...

  13. 15 CFR 700.10 - Delegation of authority.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...) BUREAU OF INDUSTRY AND SECURITY, DEPARTMENT OF COMMERCE NATIONAL SECURITY INDUSTRIAL BASE REGULATIONS DEFENSE PRIORITIES AND ALLOCATIONS SYSTEM Industrial Priorities § 700.10 Delegation of authority. (a) The... respect to industrial resources have been delegated to the Secretary of Commerce under Executive Order...

  14. Priority Techniques for High Occupancy Vehicles : State-of-the-Art Overview

    DOT National Transportation Integrated Search

    1975-11-01

    The report, part of a series of publications based on research and development efforts is a concise state-of-the-art overview of priority techniques for high occupancy vehicles (buses, carpools, and vanpools). The report identifies and summarizes sel...

  15. Utilization of An NCI Infrastructure to Evaluate Breast Cancer Patient Outcomes of Importance in Determining Priorities for New Health Care Reform.

    DTIC Science & Technology

    1997-09-01

    California has made outcomes research a vital priority, as evidence - based medicine will soon dictate breast cancer practice patterns and insurance coverage...results reported to date. I also emphasize outcomes research methodology in an attempt to define treatments guidelines from an evidence - based medicine approach...techniques such as decision analysis, cost- effectiveness, and evidence - based medicine . The goal of the new inpatient service is to optimize the value of

  16. Prioritization of Stockpile Maintenance with Layered Pareto Fronts

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

    Burke, Sarah E.; Anderson-Cook, Christine M.; Lu, Lu

    Difficult choices are required for a decision-making process where resources and budgets are increasingly constrained. This study demonstrates a structured decision-making approach using layered Pareto fronts to identify priorities about how to allocate funds between munitions stockpiles based on their estimated reliability, the urgency of needing available units, and the consequences if adequate numbers of units are not available. This case study, while specific to the characteristics of a group of munitions stockpiles, illustrates the general process of structured decision-making based on first identifying appropriate metrics that summarize the important dimensions of the decision, and then objectively eliminating non-contenders frommore » further consideration. Finally, the final subjective stage incorporates user priorities to select the four stockpiles to receive additional maintenance and surveillance funds based on understanding the trade-offs and robustness to various user priorities.« less

  17. Prioritization of Stockpile Maintenance with Layered Pareto Fronts

    DOE PAGES

    Burke, Sarah E.; Anderson-Cook, Christine M.; Lu, Lu; ...

    2017-10-11

    Difficult choices are required for a decision-making process where resources and budgets are increasingly constrained. This study demonstrates a structured decision-making approach using layered Pareto fronts to identify priorities about how to allocate funds between munitions stockpiles based on their estimated reliability, the urgency of needing available units, and the consequences if adequate numbers of units are not available. This case study, while specific to the characteristics of a group of munitions stockpiles, illustrates the general process of structured decision-making based on first identifying appropriate metrics that summarize the important dimensions of the decision, and then objectively eliminating non-contenders frommore » further consideration. Finally, the final subjective stage incorporates user priorities to select the four stockpiles to receive additional maintenance and surveillance funds based on understanding the trade-offs and robustness to various user priorities.« less

  18. Evidence gaps in advanced cancer care: community-based clinicians' perspectives and priorities for CER.

    PubMed

    Lowry, Sarah J; Loggers, Elizabeth T; Bowles, Erin J A; Wagner, Edward H

    2012-05-01

    Although much effort has focused on identifying national comparative effectiveness research (CER) priorities, little is known about the CER priorities of community-based practitioners treating patients with advanced cancer. CER priorities of managed care-based clinicians may be valuable as reflections of both payer and provider research interests. We conducted mixed methods interviews with 10 clinicians (5 oncologists and 5 pharmacists) at 5 health plans within the Health Maintenance Organization Cancer Research Network. We asked, "What evidence do you most wish you had when treating patients with advanced cancer" and questioned participants on their impressions and knowledge of CER and pragmatic clinical trials (PCTs). We conducted qualitative analyses to identify themes across interviews. Ninety percent of participants had heard of CER, 20% had heard of PCTs, and all rated CER/PCTs as highly relevant to patient and health plan decision making. Each participant offered between 3 and 10 research priorities. Half (49%) involved head-to-head treatment comparisons; another 20% involved comparing different schedules or dosing regimens of the same treatment. The majority included alternative outcomes to survival (eg, toxicity, quality of life, noninferiority). Participants cited several limitations to existing evidence, including lack of generalizability, funding biases, and rapid development of new treatments. Head-to-head treatment comparisons remain a major evidence need among community- based oncology clinicians, and CER/PCTs are highly valued methods to address the limitations of traditional randomized trials, answer questions of cost-effectiveness or noninferiority, and inform data-driven dialogue and decision making by all stakeholders.

  19. Establishing research priorities for patient safety in emergency medicine: a multidisciplinary consensus panel.

    PubMed

    Plint, Amy C; Stang, Antonia S; Calder, Lisa A

    2015-01-01

    Patient safety in the context of emergency medicine is a relatively new field of study. To date, no broad research agenda for patient safety in emergency medicine has been established. The objective of this study was to establish patient safety-related research priorities for emergency medicine. These priorities would provide a foundation for high-quality research, important direction to both researchers and health-care funders, and an essential step in improving health-care safety and patient outcomes in the high-risk emergency department (ED) setting. A four-phase consensus procedure with a multidisciplinary expert panel was organized to identify, assess, and agree on research priorities for patient safety in emergency medicine. The 19-member panel consisted of clinicians, administrators, and researchers from adult and pediatric emergency medicine, patient safety, pharmacy, and mental health; as well as representatives from patient safety organizations. In phase 1, we developed an initial list of potential research priorities by electronically surveying a purposeful and convenience sample of patient safety experts, ED clinicians, administrators, and researchers from across North America using contact lists from multiple organizations. We used simple content analysis to remove duplication and categorize the research priorities identified by survey respondents. Our expert panel reached consensus on a final list of research priorities through an in-person meeting (phase 3) and two rounds of a modified Delphi process (phases 2 and 4). After phases 1 and 2, 66 unique research priorities were identified for expert panel review. At the end of phase 4, consensus was reached for 15 research priorities. These priorities represent four themes: (1) methods to identify patient safety issues (five priorities), (2) understanding human and environmental factors related to patient safety (four priorities), (3) the patient perspective (one priority), and (4) interventions for improving patient safety (five priorities). This study established expert, consensus-based research priorities for patient safety in emergency medicine. This framework could be used by researchers and health-care funders and represents an essential guiding step towards enhancing quality of care and patient safety in the ED.

  20. Naval Supply Systems Command Fleet Logistics Center

    DTIC Science & Technology

    2012-08-08

    Partial small business set - aside is a potential consideration   12-month Base plus two options   Synopsis N00604-11-R-3006 on NECO and FedBizOpps...2012 Navy Gold Coast Small Business Procurement Event 8 August 2012 #1 PRIORITY = Operating Forces Support …while ensuring Joint...while ensuring Joint Base Success FedBid.com Reverse Auction Website 8 Small Business Assistance #1 PRIORITY = Operating Forces

  1. A Scheduling Algorithm for Cloud Computing System Based on the Driver of Dynamic Essential Path.

    PubMed

    Xie, Zhiqiang; Shao, Xia; Xin, Yu

    2016-01-01

    To solve the problem of task scheduling in the cloud computing system, this paper proposes a scheduling algorithm for cloud computing based on the driver of dynamic essential path (DDEP). This algorithm applies a predecessor-task layer priority strategy to solve the problem of constraint relations among task nodes. The strategy assigns different priority values to every task node based on the scheduling order of task node as affected by the constraint relations among task nodes, and the task node list is generated by the different priority value. To address the scheduling order problem in which task nodes have the same priority value, the dynamic essential long path strategy is proposed. This strategy computes the dynamic essential path of the pre-scheduling task nodes based on the actual computation cost and communication cost of task node in the scheduling process. The task node that has the longest dynamic essential path is scheduled first as the completion time of task graph is indirectly influenced by the finishing time of task nodes in the longest dynamic essential path. Finally, we demonstrate the proposed algorithm via simulation experiments using Matlab tools. The experimental results indicate that the proposed algorithm can effectively reduce the task Makespan in most cases and meet a high quality performance objective.

  2. A Scheduling Algorithm for Cloud Computing System Based on the Driver of Dynamic Essential Path

    PubMed Central

    Xie, Zhiqiang; Shao, Xia; Xin, Yu

    2016-01-01

    To solve the problem of task scheduling in the cloud computing system, this paper proposes a scheduling algorithm for cloud computing based on the driver of dynamic essential path (DDEP). This algorithm applies a predecessor-task layer priority strategy to solve the problem of constraint relations among task nodes. The strategy assigns different priority values to every task node based on the scheduling order of task node as affected by the constraint relations among task nodes, and the task node list is generated by the different priority value. To address the scheduling order problem in which task nodes have the same priority value, the dynamic essential long path strategy is proposed. This strategy computes the dynamic essential path of the pre-scheduling task nodes based on the actual computation cost and communication cost of task node in the scheduling process. The task node that has the longest dynamic essential path is scheduled first as the completion time of task graph is indirectly influenced by the finishing time of task nodes in the longest dynamic essential path. Finally, we demonstrate the proposed algorithm via simulation experiments using Matlab tools. The experimental results indicate that the proposed algorithm can effectively reduce the task Makespan in most cases and meet a high quality performance objective. PMID:27490901

  3. Optimum Guidance Law and Information Management for a Large Number of Formation Flying Spacecrafts

    NASA Astrophysics Data System (ADS)

    Tsuda, Yuichi; Nakasuka, Shinichi

    In recent years, formation flying technique is recognized as one of the most important technologies for deep space and orbital missions that involve multiple spacecraft operations. Formation flying mission improves simultaneous observability over a wide area, redundancy and reconfigurability of the system with relatively small and low cost spacecrafts compared with the conventional single spacecraft mission. From the viewpoint of guidance and control, realizing formation flying mission usually requires tight maintenance and control of the relative distances, speeds and orientations between the member satellites. This paper studies a practical architecture for formation flight missions focusing mainly on guidance and control, and describes a new guidance algorithm for changing and keeping the relative positions and speeds of the satellites in formation. The resulting algorithm is suitable for onboard processing and gives the optimum impulsive trajectory for satellites flying closely around a certain reference orbit, that can be elliptic, parabolic or hyperbolic. Based on this guidance algorithm, this study introduces an information management methodology between the member spacecrafts which is suitable for a large formation flight architecture. Routing and multicast communication based on the wireless local area network technology are introduced. Some mathematical analyses and computer simulations will be shown in the presentation to reveal the feasibility of the proposed formation flight architecture, especially when a very large number of satellites join the formation.

  4. Priority Determination of Underwater Tourism Site Development in Gorontalo Province using Analytical Hierarchy Process (AHP)

    NASA Astrophysics Data System (ADS)

    Rohandi, M.; Tuloli, M. Y.; Jassin, R. T.

    2018-02-01

    This research aims to determine the development of priority of underwater tourism in Gorontalo province using the Analytical Hierarchy Process (AHP) method which is one of DSS methods applying Multi-Attribute Decision Making (MADM). This method used 5 criteria and 28 alternatives to determine the best priority of underwater tourism site development in Gorontalo province. Based on the AHP calculation it appeared that the best priority development of underwater tourism site is Pulau Cinta whose total AHP score is 0.489 or 48.9%. This DSS produced a reliable result, faster solution, time-saving, and low cost for the decision makers to obtain the best underwater tourism site to be developed.

  5. Preliminary concept for statewide intercity bus and rail transit system : priority corridor ranking and analysis.

    DOT National Transportation Integrated Search

    2009-03-01

    This product summarizes the preliminary concept and priority corridors for development of a potential : statewide intercity bus and rail network. The concept is based upon the results of Tasks 1 through 5 of Texas : Department of Transportation Proje...

  6. 7 CFR 1466.5 - National allocation and management.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... adjustments to national priorities and information about resource concerns and program performance. The data used in the allocation formula will be updated as they become available. (b) Provide a performance...) Establish State level EQIP performance goals based on national, regional, and State priorities. (d) Ensure...

  7. 78 FR 9869 - Proposed Priorities-National Institute on Disability and Rehabilitation Research-Rehabilitation...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-12

    ... and rehabilitation research; (2) foster an exchange of expertise, information, and training methods to... observational findings, and creating other sources of research-based information. This research stage may....133B-6.] Proposed Priorities--National Institute on Disability and Rehabilitation Research...

  8. ZBB--a new skill for the financial manager.

    PubMed

    Thompson, G B; Pyhrr, P A

    1979-03-01

    Zero-based budgeting (ZBB) is a management decision-making tool currently gaining wide acceptance. ZBB is a budgeting approach which is useful for planning, controlling and coordinating financial and human resources. It involves the re-evaluation of all budgeted activities in terms of priorities established by the management. The traditional process of incremental budgeting differs from ZBB in that only the planned changes are evaluated in the former. In incremental budgeting, the base budget is considered authorized and required little attention. The ZBB process focuses on the whol budget. This is accomplished by: (1) identifying decision units; (2) evaluating each decision unit in terms of performance, costs, benefits, and alternate means of accomplishiing the objectives; (3) ranking the decision packages; and (4) preparing a budget for the highest priority decision packages. The effect of the ZBB approach is that new high priority programs may be funded by eliminating or reducing existing lower-priority programs. ZBB is viewed as a logical process which can combine many of the elements of good management.

  9. Proportional fair scheduling algorithm based on traffic in satellite communication system

    NASA Astrophysics Data System (ADS)

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

    2018-02-01

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

  10. User modeling techniques for enhanced usability of OPSMODEL operations simulation software

    NASA Technical Reports Server (NTRS)

    Davis, William T.

    1991-01-01

    The PC based OPSMODEL operations software for modeling and simulation of space station crew activities supports engineering and cost analyses and operations planning. Using top-down modeling, the level of detail required in the data base can be limited to being commensurate with the results required of any particular analysis. To perform a simulation, a resource environment consisting of locations, crew definition, equipment, and consumables is first defined. Activities to be simulated are then defined as operations and scheduled as desired. These operations are defined within a 1000 level priority structure. The simulation on OPSMODEL, then, consists of the following: user defined, user scheduled operations executing within an environment of user defined resource and priority constraints. Techniques for prioritizing operations to realistically model a representative daily scenario of on-orbit space station crew activities are discussed. The large number of priority levels allows priorities to be assigned commensurate with the detail necessary for a given simulation. Several techniques for realistic modeling of day-to-day work carryover are also addressed.

  11. Performance-based workload assessment: Allocation strategy and added task sensitivity

    NASA Technical Reports Server (NTRS)

    Vidulich, Michael A.

    1990-01-01

    The preliminary results of a research program investigating the use of added tasks to evaluate mental workload are reviewed. The focus of the first studies was a reappraisal of the traditional secondary task logic that encouraged the use of low-priority instructions for the added task. It was believed that such low-priority tasks would encourage subjects to split their available resources among the two tasks. The primary task would be assigned all the resources it needed, and any remaining reserve capacity would be assigned to the secondary task. If the model were correct, this approach was expected to combine sensitivity to primary task difficulty with unintrusiveness to primary task performance. The first studies of the current project demonstrated that a high-priority added task, although intrusive, could be more sensitive than the traditional low-priority secondary task. These results suggested that a more appropriate model of the attentional effects associated with added task performance might be based on capacity switching, rather than the traditional optimal allocation model.

  12. [The Danish Debate on Priority Setting in Medicine--An Update].

    PubMed

    Pornak, S C; Raspe, H

    2015-09-01

    In the last years, the Danish debate about priority setting in medicine has gained new strength. This paper shows the main focuses of the current discussion based on a research of Danish primary literature. For the first time since the 1990s the Danish Council of Ethics has been involved with priority setting in medicine in a project running from 2011 to 2013. The Council emphasises the importance of legitimate processes and calls for visible values and criteria. A focus of the debate is how to deal with new expensive drugs. Politicians, physicians, health economists and the Council of Ethics have called for a national institution for priority setting in medicine. They have mainly looked to the Norwegian National Council for Priority Setting in Health Care and the British National Institute for Health and Care Excellence for inspiration. The Danish Government considered establishing a national institute for priority setting, but the plans were not put into practice. In the year 2012 a new national project was launched to create clinical guidelines. Danish doctors welcome the guidelines as a good basis for priority setting. Just like in earlier Danish priority setting debates, a coordinating institution is lacking to bundle the discussion and keep it going. The debate seems to have come to an end once again. The fact that it was seriously considered to establish an institute for priority setting is a new development. It can be expected that the discussion will be resumed in the near future, possibly the idea of an institute for priority setting will be readopted. The general conditions for priority setting in health care have improved. © Georg Thieme Verlag KG Stuttgart · New York.

  13. Occupational health research priorities in Malaysia: a Delphi study

    PubMed Central

    Sadhra, S; Beach, J; Aw, T; Sheikh-Ahmed, K

    2001-01-01

    OBJECTIVES—As part of a consultancy project on occupational health, the Delphi method was used to identify research priorities in occupational health in Malaysia.
METHODS—Participation was sought from government ministries, industry, and professional organisations, and university departments with an interest in occupational and public health. Two rounds of questionnaires resulted in a final list of priorities, with noticeable differences between participants depending on whether they worked in industry or were from government organisations.
RESULTS—The participation rate of 71% (55 of 78) was obtained for the first questionnaire and 76% (72 of 95) for the second questionnaire. The participants identified occupational health problems for specific groups and industries as the top research priority area (ranked as top priority by 25% of participants). Ministry of Health participants placed emphasis on healthcare workers (52% ranking it as top priority), whereas those from industry identified construction and plantation workers as groups, which should be accorded the highest priority. Evaluation of research and services was given a low priority.
CONCLUSIONS—The priorities for occupational health determined with the Delphi approach showed differences between Malaysia, a developing country, and findings from similar European studies. This may be expected, as differences exist in stages of economic development, types of industries, occupational activities, and cultural attitudes to occupational health and safety. Chemical poisonings and workplace accidents were accorded a high priority. By contrast with findings from western countries, workplace psychosocial problems and musculoskeletal injuries were deemed less important. There also seemed to be greater emphasis on adopting interventions for identified problems based on experience in other countries rather than the need to evaluate local occupational health provisions.


Keywords: occupational health; research priorities; Malaysia PMID:11404445

  14. Occupational health research priorities in Malaysia: a Delphi study.

    PubMed

    Sadhra, S; Beach, J R; Aw, T C; Sheikh-Ahmed, K

    2001-07-01

    As part of a consultancy project on occupational health, the Delphi method was used to identify research priorities in occupational health in Malaysia. Participation was sought from government ministries, industry, and professional organisations, and university departments with an interest in occupational and public health. Two rounds of questionnaires resulted in a final list of priorities, with noticeable differences between participants depending on whether they worked in industry or were from government organisations. The participation rate of 71% (55 of 78) was obtained for the first questionnaire and 76% (72 of 95) for the second questionnaire. The participants identified occupational health problems for specific groups and industries as the top research priority area (ranked as top priority by 25% of participants). Ministry of Health participants placed emphasis on healthcare workers (52% ranking it as top priority), whereas those from industry identified construction and plantation workers as groups, which should be accorded the highest priority. Evaluation of research and services was given a low priority. The priorities for occupational health determined with the Delphi approach showed differences between Malaysia, a developing country, and findings from similar European studies. This may be expected, as differences exist in stages of economic development, types of industries, occupational activities, and cultural attitudes to occupational health and safety. Chemical poisonings and workplace accidents were accorded a high priority. By contrast with findings from western countries, workplace psychosocial problems and musculoskeletal injuries were deemed less important. There also seemed to be greater emphasis on adopting interventions for identified problems based on experience in other countries rather than the need to evaluate local occupational health provisions.

  15. A modified priority list-based MILP method for solving large-scale unit commitment problems

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

    Ke, Xinda; Lu, Ning; Wu, Di

    This paper studies the typical pattern of unit commitment (UC) results in terms of generator’s cost and capacity. A method is then proposed to combine a modified priority list technique with mixed integer linear programming (MILP) for UC problem. The proposed method consists of two steps. At the first step, a portion of generators are predetermined to be online or offline within a look-ahead period (e.g., a week), based on the demand curve and generator priority order. For the generators whose on/off status is predetermined, at the second step, the corresponding binary variables are removed from the UC MILP problemmore » over the operational planning horizon (e.g., 24 hours). With a number of binary variables removed, the resulted problem can be solved much faster using the off-the-shelf MILP solvers, based on the branch-and-bound algorithm. In the modified priority list method, scale factors are designed to adjust the tradeoff between solution speed and level of optimality. It is found that the proposed method can significantly speed up the UC problem with minor compromise in optimality by selecting appropriate scale factors.« less

  16. Priority setting for orphan drugs: an international comparison.

    PubMed

    Rosenberg-Yunger, Zahava R S; Daar, Abdallah S; Thorsteinsdóttir, Halla; Martin, Douglas K

    2011-04-01

    To describe the process of priority setting for two orphan drugs - Cerezyme and Fabrazyme - in Canada, Australia and Israel, in order to understand and improve the process based on stakeholder perspectives. We conducted qualitative case studies of how three independent drug advisory committees made decisions relating to the funding of Cerezyme and Fabrazyme. Interviews were conducted with 22 informants, including committee members, patient groups and industry representatives. (1) DESCRIPTION: Orphan drugs reimbursement recommendations by expert panels were based on clinical evidence, cost and cost-effectiveness analysis. (2) EVALUATION: Committee members expressed an overall preference for the current drug review process used by their own committee, but were concerned with the fairness of the process particularly for orphan drugs. Other informants suggested the inclusion of other relevant values (e.g. lack of alternative treatments) in order to improve the priority setting process. Some patient groups suggested the use of an alternative funding mechanism for orphan drugs. Priority setting for drugs is not solely a technical process (involving cost-effective analysis, evidence-based medicine, etc.). Understanding the process by which reimbursement decisions are made for orphan drugs may help improve the system for future orphan drugs. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  17. Using Photovoice, Latina Transgender Women Identify Priorities in a New Immigrant-Destination State

    PubMed Central

    Rhodes, Scott D.; Alonzo, Jorge; Mann, Lilli; Simán, Florence; Garcia, Manuel; Abraham, Claire; Sun, Christina J.

    2016-01-01

    Little is known about the immigrant Latino/a transgender community in the southeastern United States. This study used photovoice, a methodology aligned with community-based participatory research, to explore needs, assets, and priorities of Latina transgender women in North Carolina. Nine immigrant Latina male-to-female transgender women documented their daily experiences through photography, engaged in empowerment-based photo-discussions, and organized a bilingual community forum to move knowledge to action. From the participants’ photographs and words, 11 themes emerged in three domains: daily challenges (e.g., health risks, uncertainty about the future, discrimination, and anxiety about family reactions); needs and priorities (e.g., health and social services, emotional support, and collective action); and community strengths and assets (e.g., supportive individuals and institutions, wisdom through lived experiences, and personal and professional goals). At the community forum, 60 influential advocates, including Latina transgender women, representatives from community-based organizations, health and social service providers, and law enforcement, reviewed findings and identified ten recommended actions. Overall, photovoice served to obtain rich qualitative insight into the lived experiences of Latina transgender women that was then shared with local leaders and agencies to help address priorities. PMID:27110226

  18. Complementarity and Area-Efficiency in the Prioritization of the Global Protected Area Network.

    PubMed

    Kullberg, Peter; Toivonen, Tuuli; Montesino Pouzols, Federico; Lehtomäki, Joona; Di Minin, Enrico; Moilanen, Atte

    2015-01-01

    Complementarity and cost-efficiency are widely used principles for protected area network design. Despite the wide use and robust theoretical underpinnings, their effects on the performance and patterns of priority areas are rarely studied in detail. Here we compare two approaches for identifying the management priority areas inside the global protected area network: 1) a scoring-based approach, used in recently published analysis and 2) a spatial prioritization method, which accounts for complementarity and area-efficiency. Using the same IUCN species distribution data the complementarity method found an equal-area set of priority areas with double the mean species ranges covered compared to the scoring-based approach. The complementarity set also had 72% more species with full ranges covered, and lacked any coverage only for half of the species compared to the scoring approach. Protected areas in our complementarity-based solution were on average smaller and geographically more scattered. The large difference between the two solutions highlights the need for critical thinking about the selected prioritization method. According to our analysis, accounting for complementarity and area-efficiency can lead to considerable improvements when setting management priorities for the global protected area network.

  19. The evolution of PBMA: towards a macro-level priority setting framework for health regions.

    PubMed

    Mitton, Craig R; Donaldson, Cam; Waldner, Howard; Eagle, Chris

    2003-11-01

    To date, relatively little work on priority setting has been carried out at a macro-level across major portfolios within integrated health care organizations. This paper describes a macro marginal analysis (MMA) process for setting priorities and allocating resources in health authorities, based on work carried out in a major urban health region in Alberta, Canada. MMA centers around an expert working group of managers and clinicians who are charged with identifying areas for resource re-allocation on an ongoing basis. Trade-offs between services are based on locally defined criteria and are informed by multiple inputs such as evidence from the literature and local expert opinion. The approach is put forth as a significant improvement on historical resource allocation patterns.

  20. Optimizing farm landscape by two decision-support tools for present and future: A case study in a mountainous farm of Taiwan

    NASA Astrophysics Data System (ADS)

    Chou, S.; Lin, Y.

    2013-12-01

    Rapid expansion of agricultural land-use has been identified as the main factor degrading biodiversity. Many studies have indicated that habitat quality and connectivity for multiple species can be preserved by applying the systematic conservation planning and software programs for spatial conservation prioritizations are usually used by planners to solve conservation problems for present and future. However, each conservation software program uses different algorithms and may not be suitable or efficient for all case studies. Therefore, in this study we compared the performance of two commonly used decision-support tools, Marxan and Zonation, on identifying priority areas as reserve region for 16 bird species in the mountain area of Taiwan. The priority areas are considered as the results of the tradeoff between bird presence (biological factor) and agricultural products (economic factor). Marxan uses the minimum set approach to identify priority areas for meeting specific targets while Zonation uses the maximum coverage approach to identify priority areas given a fixed budget. Therefore, we design the scenario with the most comparable setting, which selects target-based planning as the removal rule and boundary length penalty option in zonation. The landscape composition and configuration of the simulated priority areas were further evaluated by using landscape metrics and their similarity were examined by using Spearman's rank tests. The results showed that Marxan performed more efficiently while Zonation generated the priority areas in better connectivity. As the selection of conservation programs depends on users objectives and needs for present and future, this study provides useful information on determining suitable and efficient decision-support tools for future bird conservation. Conservation maps for Zonation based on different BLP parameter. The conservation value for Zonation is based on the hierarchical solution output. (a)BLP =1000 (b)BLP =3000 (c)BLP =5000 (d)BLP =7000 Conservation maps for Marxan based on different BMP parameter. The conservation value for Marxan is based on the selection frequency. (a)BMP =2500 (b)BMP =5000 (c)BMP =7500 (d)BMP =10000

  1. Protecting Biodiversity when Money Matters: Maximizing Return on Investment

    PubMed Central

    Underwood, Emma C.; Shaw, M. Rebecca; Wilson, Kerrie A.; Kareiva, Peter; Klausmeyer, Kirk R.; McBride, Marissa F.; Bode, Michael; Morrison, Scott A.; Hoekstra, Jonathan M.; Possingham, Hugh P.

    2008-01-01

    Background Conventional wisdom identifies biodiversity hotspots as priorities for conservation investment because they capture dense concentrations of species. However, density of species does not necessarily imply conservation ‘efficiency’. Here we explicitly consider conservation efficiency in terms of species protected per dollar invested. Methodology/Principal Findings We apply a dynamic return on investment approach to a global biome and compare it with three alternate priority setting approaches and a random allocation of funding. After twenty years of acquiring habitat, the return on investment approach protects between 32% and 69% more species compared to the other priority setting approaches. To correct for potential inefficiencies of protecting the same species multiple times we account for the complementarity of species, protecting up to three times more distinct vertebrate species than alternate approaches. Conclusions/Significance Incorporating costs in a return on investment framework expands priorities to include areas not traditionally highlighted as priorities based on conventional irreplaceability and vulnerability approaches. PMID:18231601

  2. Global Climate Change Adaptation Priorities for Biodiversity and Food Security

    PubMed Central

    Hannah, Lee; Ikegami, Makihiko; Hole, David G.; Seo, Changwan; Butchart, Stuart H. M.; Peterson, A. Townsend; Roehrdanz, Patrick R.

    2013-01-01

    International policy is placing increasing emphasis on adaptation to climate change, including the allocation of new funds to assist adaptation efforts. Climate change adaptation funding may be most effective where it meets integrated goals, but global geographic priorities based on multiple development and ecological criteria are not well characterized. Here we show that human and natural adaptation needs related to maintaining agricultural productivity and ecosystem integrity intersect in ten major areas globally, providing a coherent set of international priorities for adaptation funding. An additional seven regional areas are identified as worthy of additional study. The priority areas are locations where changes in crop suitability affecting impoverished farmers intersect with changes in ranges of restricted-range species. Agreement among multiple climate models and emissions scenarios suggests that these priorities are robust. Adaptation funding directed to these areas could simultaneously address multiple international policy goals, including poverty reduction, protecting agricultural production and safeguarding ecosystem services. PMID:23991125

  3. Global climate change adaptation priorities for biodiversity and food security.

    PubMed

    Hannah, Lee; Ikegami, Makihiko; Hole, David G; Seo, Changwan; Butchart, Stuart H M; Peterson, A Townsend; Roehrdanz, Patrick R

    2013-01-01

    International policy is placing increasing emphasis on adaptation to climate change, including the allocation of new funds to assist adaptation efforts. Climate change adaptation funding may be most effective where it meets integrated goals, but global geographic priorities based on multiple development and ecological criteria are not well characterized. Here we show that human and natural adaptation needs related to maintaining agricultural productivity and ecosystem integrity intersect in ten major areas globally, providing a coherent set of international priorities for adaptation funding. An additional seven regional areas are identified as worthy of additional study. The priority areas are locations where changes in crop suitability affecting impoverished farmers intersect with changes in ranges of restricted-range species. Agreement among multiple climate models and emissions scenarios suggests that these priorities are robust. Adaptation funding directed to these areas could simultaneously address multiple international policy goals, including poverty reduction, protecting agricultural production and safeguarding ecosystem services.

  4. Methodological Pluralism: The Gold Standard of STEM Evaluation

    ERIC Educational Resources Information Center

    Lawrenz, Frances; Huffman, Douglas

    2006-01-01

    Nationally, there is continuing debate about appropriate methods for conducting educational evaluations. The U.S. Department of Education has placed a priority on "scientifically" based evaluation methods and has advocated a "gold standard" of randomized controlled experimentation. The priority suggests that randomized control methods are best,…

  5. Market segmentation using perceived constraints

    Treesearch

    Jinhee Jun; Gerard Kyle; Andrew Mowen

    2008-01-01

    We examined the practical utility of segmenting potential visitors to Cleveland Metroparks using their constraint profiles. Our analysis identified three segments based on their scores on the dimensions of constraints: Other priorities--visitors who scored the highest on 'other priorities' dimension; Highly Constrained--visitors who scored relatively high on...

  6. Setting Priorities Among Educational Objectives.

    ERIC Educational Resources Information Center

    Sutjipto, Sudijarto; And Others

    This publication is intended to aid educational planners in developing nations in translating national goals and aspirations into educational objectives and in establishing and quantifying priorities among educational objectives. Much of the content is based on a model for setting educational objectives that was developed in Indonesia in 1972. The…

  7. 77 FR 40601 - Final Priority: Disability and Rehabilitation Research Projects and Centers Program; Disability...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-10

    ... analyses of data, producing observational findings, and creating other sources of research-based... provide a rationale for the stage of research being proposed and the research methods associated with the... DEPARTMENT OF EDUCATION Final Priority: Disability and Rehabilitation Research Projects and...

  8. 78 FR 27038 - Final Priorities; National Institute on Disability and Rehabilitation Research-Rehabilitation...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-09

    ... observational research or research toward the development of diagnostic or outcome assessment tools. The... observational findings, and creating other sources of research-based information. This research stage may....133B-6] Final Priorities; National Institute on Disability and Rehabilitation Research--Rehabilitation...

  9. NASA Tech Briefs, March 2007

    NASA Technical Reports Server (NTRS)

    2007-01-01

    Topics include: Advanced Systems for Monitoring Underwater Sounds; Wireless Data-Acquisition System for Testing Rocket Engines; Processing Raw HST Data With Up-to-Date Calibration Data; Mobile Collection and Automated Interpretation of EEG Data; System for Secure Integration of Aviation Data; Servomotor and Controller Having Large Dynamic Range; Digital Multicasting of Multiple Audio Streams; Translator for Optimizing Fluid-Handling Components; AIRSAR Web-Based Data Processing; Pattern Matcher for Trees Constructed From Lists; Reducing a Knowledge-Base Search Space When Data Are Missing; Ground-Based Correction of Remote-Sensing Spectral Imagery; State-Chart Autocoder; Pointing History Engine for the Spitzer Space Telescope; Low-Friction, High-Stiffness Joint for Uniaxial Load Cell; Magnet-Based System for Docking of Miniature Spacecraft; Electromechanically Actuated Valve for Controlling Flow Rate; Plumbing Fixture for a Microfluidic Cartridge; Camera Mount for a Head-Up Display; Core-Cutoff Tool; Recirculation of Laser Power in an Atomic Fountain; Simplified Generation of High-Angular-Momentum Light Beams; Imaging Spectrometer on a Chip; Interferometric Quantum-Nondemolition Single-Photon Detectors; Ring-Down Spectroscopy for Characterizing a CW Raman Laser; Complex Type-II Interband Cascade MQW Photodetectors; Single-Point Access to Data Distributed on Many Processors; Estimating Dust and Water Ice Content of the Martian Atmosphere From THEMIS Data; Computing a Stability Spectrum by Use of the HHT; Theoretical Studies of Routes to Synthesis of Tetrahedral N4; Estimation Filter for Alignment of the Spitzer Space Telescope; Antenna for Measuring Electric Fields Within the Inner Heliosphere; Improved High-Voltage Gas Isolator for Ion Thruster; and Hybrid Mobile Communication Networks for Planetary Exploration.

  10. Chartered Society of Physiotherapy's identification of national research priorities for physiotherapy using a modified Delphi technique.

    PubMed

    Rankin, Gabrielle; Rushton, Alison; Olver, Pat; Moore, Ann

    2012-09-01

    To define research priorities to strategically inform the evidence base for physiotherapy practice. A modified Delphi method using SurveyMonkey software identified priorities for physiotherapy research through national consensus. An iterative process of three rounds provided feedback. Round 1 requested five priorities using pre-defined prioritisation criteria. Content analysis identified research themes and topics. Round 2 requested rating of the importance of the research topics using a 1-5 Likert scale. Round 3 requested a further process of rating. Quantitative and qualitative data informed decision-making. Level of consensus was established as mean rating ≥ 3.5, coefficient of variation ≤ 30%, and ≥ 55% agreement. Consensus across participants was evaluated using Kendall's W. Four expert panels (n=40-61) encompassing a range of stakeholders and reflecting four core areas of physiotherapy practice were established by steering groups (n=204 participants overall). Response rates of 53-78% across three rounds were good. The identification of 24/185 topics for musculoskeletal, 43/174 for neurology, 30/120 for cardiorespiratory and medical rehabilitation, and 30/113 for mental and physical health and wellbeing as priorities demonstrated discrimination of the process. Consensus between participants was good for most topics. Measurement validity of the research topics was good. The involvement of multiple stakeholders as participants ensured the current context of the intended use of the priorities. From a process of national consensus involving key stakeholders, including service users, physiotherapy research topics have been identified and prioritised. Setting priorities provides a vision of how research can contribute to the developing research base in physiotherapy to maximise focus. Copyright © 2012 Chartered Society of Physiotherapy. Published by Elsevier Ltd. All rights reserved.

  11. Stakeholder Engagement to Identify Priorities for Improving the Quality and Value of Critical Care.

    PubMed

    Stelfox, Henry T; Niven, Daniel J; Clement, Fiona M; Bagshaw, Sean M; Cook, Deborah J; McKenzie, Emily; Potestio, Melissa L; Doig, Christopher J; O'Neill, Barbara; Zygun, David

    2015-01-01

    Large amounts of scientific evidence are generated, but not implemented into patient care (the 'knowledge-to-care' gap). We identified and prioritized knowledge-to-care gaps in critical care as opportunities to improve the quality and value of healthcare. We used a multi-method community-based participatory research approach to engage a Network of all adult (n = 14) and pediatric (n = 2) medical-surgical intensive care units (ICUs) in a fully integrated geographically defined healthcare system serving 4 million residents. Participants included Network oversight committee members (n = 38) and frontline providers (n = 1,790). Network committee members used a modified RAND/University of California Appropriateness Methodology, to serially propose, rate (validated 9 point scale) and revise potential knowledge-to-care gaps as priorities for improvement. The priorities were sent to frontline providers for evaluation. Results were relayed back to all frontline providers for feedback. Initially, 68 knowledge-to-care gaps were proposed, rated and revised by the committee (n = 32 participants) over 3 rounds of review and resulted in 13 proposed priorities for improvement. Then, 1,103 providers (62% response rate) evaluated the priorities, and rated 9 as 'necessary' (median score 7-9). Several factors were associated with rating priorities as necessary in multivariable logistic regression, related to the provider (experience, teaching status of ICU) and topic (strength of supporting evidence, potential to benefit the patient, potential to improve patient/family experience, potential to decrease costs). A community-based participatory research approach engaged a diverse group of stakeholders to identify 9 priorities for improving the quality and value of critical care. The approach was time and cost efficient and could serve as a model to prioritize areas for research quality improvement across other settings.

  12. A Protocol for Scalable Loop-Free Multicast Routing

    DTIC Science & Technology

    1997-01-01

    N ÁŜ+@"B�tQDVO:(#ÄŜ+ÄIO8+@D@DÀiÄq/"VÂaÀi:!8A:<B?V+B3/"V+I 8AQ "kVÄDV|¾VO¾K/"VO:J;¬K�@ÄDVNt�QDV:(𔄂+:=V|QD@D:zV+8cI#ඝ/RöV> Ä...8@DVOK¶Å�)/"Ài:�:zÀcQDÄzVO:yø|K¶@.W¢K¶ÅiQD:=Vù iIc5�T�@*(@�QR¾7/"VO:�ÀA :=VS8c;qÀi@"ILÀcQRÃMBqŜOWV I 8AQ "kV+B7¸qî�÷ï ½�ÄzÀ�8A:z:=K�WVI

  13. Engaging patients in health research: identifying research priorities through community town halls.

    PubMed

    Etchegary, Holly; Bishop, Lisa; Street, Catherine; Aubrey-Bassler, Kris; Humphries, Dale; Vat, Lidewij Eva; Barrett, Brendan

    2017-03-11

    The vision of Canada's Strategy for Patient-Oriented Research is that patients be actively engaged as partners in health research. Support units have been created across Canada to build capacity in patient-oriented research and facilitate its conduct. This study aimed to explore patients' health research priorities in the province of Newfoundland and Labrador (NL). Eight town halls were held with members of the general public in rural and urban settings across the province. Sessions were a hybrid information-consultation event, with key questions about health research priorities and outcomes guiding the discussion. Sixty eight members of the public attended town hall sessions. A broad range of health experiences in the healthcare system were recounted. Key priorities for the public included access and availability of providers and services, disease prevention and health promotion, and follow-up support and community care. In discussing their health research priorities, participants spontaneously raised a broad range of suggestions for improving the healthcare system in our jurisdiction. Public research priorities and suggestions for improving the provision of healthcare provide valuable information to guide Support Units' planning and priority-setting processes. A range of research areas were raised as priorities for patients that are likely comparable to other healthcare systems. These create a number of health research questions that would be in line with public priorities. Findings also provide lessons learned for others and add to the evidence base on patient engagement methods.

  14. Clinical Research Priorities in Adult Congenital Heart Disease

    PubMed Central

    Cotts, Timothy; Khairy, Paul; Opotowsky, Alexander R.; John, Anitha S.; Valente, Anne Marie; Zaidi, Ali N.; Cook, Stephen C.; Aboulhosn, Jamil; Ting, Jennifer Grando; Gurvitz, Michelle; Landzberg, Michael J.; Verstappen, Amy; Kay, Joseph; Earing, Michael; Franklin, Wayne; Kogon, Brian; Broberg, Craig S.

    2014-01-01

    Background Adult congenital heart disease (ACHD) clinicians are hampered by the paucity of data to inform clinical decision-making. The objective of this study was to identify priorities for clinical research in ACHD. Methods A list of 45 research questions was developed by the Alliance for Adult Research in Congenital Cardiology (AARCC), compiled into a survey, and administered to ACHD providers. Patient input was sought via the Adult Congenital Heart Association at community meetings and online forums. The 25 top questions were sent to ACHD providers worldwide via an online survey. Each question was ranked based on perceived priority and weighted based on time spent in ACHD care. The top 10 topics identified are presented and discussed. Results The final online survey yielded 139 responses. Top priority questions related to tetralogy of Fallot (timing of pulmonary valve replacement and criteria for primary prevention ICDs), patients with systemic right ventricles (determining the optimal echocardiographic techniques for measuring right ventricular function, and indications for tricuspid valve replacement and primary prevention ICDs), and single ventricle/Fontan patients (role of pulmonary vasodilators, optimal anticoagulation, medical therapy for preservation of ventricular function, treatment for protein losing enteropathy). In addition, establishing criteria to refer ACHD patients for cardiac transplantation was deemed a priority. Conclusions The ACHD field is in need of prospective research to address fundamental clinical questions. It is hoped that this methodical consultation process will inform researchers and funding organizations about clinical research topics deemed to be of high priority. PMID:24411207

  15. Clinical research priorities in adult congenital heart disease.

    PubMed

    Cotts, Timothy; Khairy, Paul; Opotowsky, Alexander R; John, Anitha S; Valente, Anne Marie; Zaidi, Ali N; Cook, Stephen C; Aboulhosn, Jamil; Ting, Jennifer Grando; Gurvitz, Michelle; Landzberg, Michael J; Verstappen, Amy; Kay, Joseph; Earing, Michael; Franklin, Wayne; Kogon, Brian; Broberg, Craig S

    2014-02-15

    Adult congenital heart disease (ACHD) clinicians are hampered by the paucity of data to inform clinical decision-making. The objective of this study was to identify priorities for clinical research in ACHD. A list of 45 research questions was developed by the Alliance for Adult Research in Congenital Cardiology (AARCC), compiled into a survey, and administered to ACHD providers. Patient input was sought via the Adult Congenital Heart Association at community meetings and online forums. The 25 top questions were sent to ACHD providers worldwide via an online survey. Each question was ranked based on perceived priority and weighted based on time spent in ACHD care. The top 10 topics identified are presented and discussed. The final online survey yielded 139 responses. Top priority questions related to tetralogy of Fallot (timing of pulmonary valve replacement and criteria for primary prevention ICDs), patients with systemic right ventricles (determining the optimal echocardiographic techniques for measuring right ventricular function, and indications for tricuspid valve replacement and primary prevention ICDs), and single ventricle/Fontan patients (role of pulmonary vasodilators, optimal anticoagulation, medical therapy for preservation of ventricular function, treatment for protein losing enteropathy). In addition, establishing criteria to refer ACHD patients for cardiac transplantation was deemed a priority. The ACHD field is in need of prospective research to address fundamental clinical questions. It is hoped that this methodical consultation process will inform researchers and funding organizations about clinical research topics deemed to be of high priority. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  16. Priority setting in HIV/AIDS control in West Java Indonesia: an evaluation based on the accountability for reasonableness framework.

    PubMed

    Tromp, Noor; Prawiranegara, Rozar; Subhan Riparev, Harris; Siregar, Adiatma; Sunjaya, Deni; Baltussen, Rob

    2015-04-01

    Indonesia has insufficient resources to adequately respond to the HIV/AIDS epidemic, and thus faces a great challenge in prioritizing interventions. In many countries, such priority setting processes are typically ad hoc and not transparent leading to unfair decisions. Here, we evaluated the priority setting process in HIV/AIDS control in West Java province against the four conditions of the accountability for reasonableness (A4R) framework: relevance, publicity, appeals and revision, and enforcement. We reviewed government documents and conducted semi-structured qualitative interviews based on the A4R framework with 22 participants of the 5-year HIV/AIDS strategy development for 2008-13 (West Java province) and 2007-11 (Bandung). We found that criteria for priority setting were used implicitly and that the strategies included a wide range of programmes. Many stakeholders were involved in the process but their contribution could be improved and particularly the public and people living with HIV/AIDS could be better engaged. The use of appeal and publicity mechanisms could be more transparent and formally stated. Public regulations are not yet installed to ensure fair priority setting. To increase fairness in HIV/AIDS priority setting, West Java should make improvements on all four conditions of the A4R framework. Published by Oxford University Press in association with The London School of Hygiene and Tropical Medicine © The Author 2014; all rights reserved.

  17. Priority setting in guideline development: article 2 in Integrating and coordinating efforts in COPD guideline development. An official ATS/ERS workshop report.

    PubMed

    Atkins, David; Perez-Padilla, Rogelio; Macnee, William; Buist, A Sonia; Cruz, Alvaro A

    2012-12-01

    Professional societies, like many other organizations around the world, have recognized the need to use more rigorous processes to ensure that health care recommendations are informed by the best available research evidence. Priority setting is an essential component of developing clinical practice guidelines informed by the best available research evidence. It ensures that resources and attention are devoted to those areas in which clinical recommendations will provide the greatest benefit to patients, clinicians, and policy makers. This is the second of a series of 14 articles that methodologists and researchers from around the world prepared to advise guideline developers in respiratory and other diseases. This review focuses on priority setting, addressing five key questions. In this review, we addressed the following questions. (1) At which steps of guideline development should priorities be considered? (2) How do we create an initial list of potential topics within the guideline? (3) What criteria should be used to establish priorities? (4) What parties should be involved and what processes should be used to set priorities? (5)What are the potential challenges of setting priorities? We updated an existing review on priority setting, and searched PubMed and other databases of methodological studies for existing systematic reviews and relevant methodological research. We did not conduct systematic reviews ourselves. Our conclusions are based on available evidence, our own experience working with guideline developers, and workshop discussions. Existing literature on priority setting largely applies to identifying priorities for which guidelines to develop rather than setting priorities for recommendations within a guideline. Nonetheless, there is substantial consensus about the general factors that should be considered in setting priorities. These include the burdens and costs of illness, potential impact of a recommendation, identified deficits or weak points in practice, variation or uncertainty in practice, and availability of evidence. The input of a variety of stakeholders is useful in setting priorities, although informal consultation is used more often than formal methods. Processes for setting priorities remains poorly described in most guidelines.

  18. Priority of VHS Development Based in Potential Area using Principal Component Analysis

    NASA Astrophysics Data System (ADS)

    Meirawan, D.; Ana, A.; Saripudin, S.

    2018-02-01

    The current condition of VHS is still inadequate in quality, quantity and relevance. The purpose of this research is to analyse the development of VHS based on the development of regional potential by using principal component analysis (PCA) in Bandung, Indonesia. This study used descriptive qualitative data analysis using the principle of secondary data reduction component. The method used is Principal Component Analysis (PCA) analysis with Minitab Statistics Software tool. The results of this study indicate the value of the lowest requirement is a priority of the construction of development VHS with a program of majors in accordance with the development of regional potential. Based on the PCA score found that the main priority in the development of VHS in Bandung is in Saguling, which has the lowest PCA value of 416.92 in area 1, Cihampelas with the lowest PCA value in region 2 and Padalarang with the lowest PCA value.

  19. Evaluating healthcare priority setting at the meso level: A thematic review of empirical literature

    PubMed Central

    Waithaka, Dennis; Tsofa, Benjamin; Barasa, Edwine

    2018-01-01

    Background: Decentralization of health systems has made sub-national/regional healthcare systems the backbone of healthcare delivery. These regions are tasked with the difficult responsibility of determining healthcare priorities and resource allocation amidst scarce resources. We aimed to review empirical literature that evaluated priority setting practice at the meso (sub-national) level of health systems. Methods: We systematically searched PubMed, ScienceDirect and Google scholar databases and supplemented these with manual searching for relevant studies, based on the reference list of selected papers. We only included empirical studies that described and evaluated, or those that only evaluated priority setting practice at the meso-level. A total of 16 papers were identified from LMICs and HICs. We analyzed data from the selected papers by thematic review. Results: Few studies used systematic priority setting processes, and all but one were from HICs. Both formal and informal criteria are used in priority-setting, however, informal criteria appear to be more perverse in LMICs compared to HICs. The priority setting process at the meso-level is a top-down approach with minimal involvement of the community. Accountability for reasonableness was the most common evaluative framework as it was used in 12 of the 16 studies. Efficiency, reallocation of resources and options for service delivery redesign were the most common outcome measures used to evaluate priority setting. Limitations: Our study was limited by the fact that there are very few empirical studies that have evaluated priority setting at the meso-level and there is likelihood that we did not capture all the studies. Conclusions: Improving priority setting practices at the meso level is crucial to strengthening health systems. This can be achieved through incorporating and adapting systematic priority setting processes and frameworks to the context where used, and making considerations of both process and outcome measures during priority setting and resource allocation. PMID:29511741

  20. Research Priorities in Mobile Learning: An International Delphi Study

    ERIC Educational Resources Information Center

    Hsu, Yu-Chang; Ching, Yu-Hui; Snelson, Chareen

    2014-01-01

    Along with advancing mobile technologies and proliferating mobile devices and applications, mobile learning research has gained great momentum in recent years. While there have been review articles summarizing past research, studies identifying mobile learning research priorities based on experts' latest insights have been lacking. This study…

  1. Setting Priorities for NIOSH Research

    ERIC Educational Resources Information Center

    Gallagher, Richard E.

    1975-01-01

    The National Institute for Occupational Safety and Health (NIOSH) is attempting to develop total programs of occupational safety and health protection. It has established research criteria and a priority system for evaluating the order of investigating suspect substances or agents based upon the expected gain of the health benefit. (Author/MW)

  2. 7 CFR 625.6 - Establishing priority for enrollment in HFRP.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... contribution of non-Federal funds; (6) Significance of forest ecosystem functions and values; (7) Estimated... place higher priority on certain forest ecosystems based regions of the State or multi-State area where... is essential to the successful restoration of the forest ecosystem and those adjacent landowners are...

  3. 7 CFR 625.6 - Establishing priority for enrollment in HFRP.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... contribution of non-Federal funds; (6) Significance of forest ecosystem functions and values; (7) Estimated... place higher priority on certain forest ecosystems based regions of the State or multi-State area where... is essential to the successful restoration of the forest ecosystem and those adjacent landowners are...

  4. 7 CFR 625.6 - Establishing priority for enrollment in HFRP.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... contribution of non-Federal funds; (6) Significance of forest ecosystem functions and values; (7) Estimated... place higher priority on certain forest ecosystems based regions of the State or multi-State area where... is essential to the successful restoration of the forest ecosystem and those adjacent landowners are...

  5. 7 CFR 625.6 - Establishing priority for enrollment in HFRP.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... contribution of non-Federal funds; (6) Significance of forest ecosystem functions and values; (7) Estimated... place higher priority on certain forest ecosystems based regions of the State or multi-State area where... is essential to the successful restoration of the forest ecosystem and those adjacent landowners are...

  6. 15 CFR 700.15 - Extension of priority ratings.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...) BUREAU OF INDUSTRY AND SECURITY, DEPARTMENT OF COMMERCE NATIONAL SECURITY INDUSTRIAL BASE REGULATIONS... receipt of a DO-A3 rated order for a navigation system and needs to purchase semiconductors for its manufacture, that person must use a DO-A3 rated order to obtain the needed semiconductors. (b) The priority...

  7. The Federal Budget: Proposed Economic and Social Priorities Leave Little Room for Education.

    ERIC Educational Resources Information Center

    NEWSNOTES: Center for Law and Education, Inc., 1982

    1982-01-01

    Outlines the latest Federal budget and regulatory proposals being discussed, examines the spending and taxation priorities on which they are based, and suggests alternatives for the funding of education and other human services. (Available from Gutman Library, 6 Appian Way, Cambridge, MA 02138.) (Author/GC)

  8. Rural Communities and Rural Social Issues: Priorities for Research.

    ERIC Educational Resources Information Center

    Black, Alan; Duff, John; Saggers, Sherry; Baines, Patricia

    This report recommends priorities for research into rural communities and rural social issues in Australia, based on an extensive literature review, surveys of policymaking agencies and researchers, and discussion at a national workshop in May 1999. Chapters 1-2 outline the study's background, purpose, and methodology; discuss issues in the…

  9. Special Education Inservice Priorities for Regular Educators.

    ERIC Educational Resources Information Center

    Bass, Michele Britton

    To identify content and format priorities for special education inservice training, 243 elementary classroom teachers in 21 schools with learning handicapped (LH) programs were surveyed. A questionnaire was developed to elicit responses to 22 topics and 21 methods of inservice training, with category selection based on a Likert-type one to four…

  10. Health Extension and Clinical and Translational Science: An Innovative Strategy for Community Engagement.

    PubMed

    Kaufman, Arthur; Rhyne, Robert L; Anastasoff, Juliana; Ronquillo, Francisco; Nixon, Marnie; Mishra, Shiraz; Poola, Charlene; Page-Reeves, Janet; Nkouaga, Carolina; Cordova, Carla; Larson, Richard S

    Health Extension Regional Officers (HEROs) through the University of New Mexico Health Sciences Center (UNMHSC) help to facilitate university-community engagement throughout New Mexico. HEROs, based in communities across the state, link priority community health needs with university resources in education, service, and research. Researchers' studies are usually aligned with federal funding priorities rather than with health priorities expressed by communities. To help overcome this misalignment, the UNM Clinical and Translational Science Center (CTSC) provides partial funding for HEROs to bridge the divide between research priorities of UNMHSC and health priorities of the state's communities. A bidirectional partnership between HEROs and CTSC researchers was established, which led to: 1) increased community engaged studies through the CTSC, 2) the HERO model itself as a subject of research, 3) a HERO-driven increase in local capacity in scholarship and grant writing, and 4) development of training modules for investigators and community stakeholders on community-engaged research. As a result, 5 grants were submitted, 4 of which were funded, totaling $7,409,002.00, and 3 research articles were published. Health extension can serve as a university-funded, community-based bridge between community health needs and Clinical and Translational Science Award (CTSA) research capacity, opening avenues for translational research. © Copyright 2017 by the American Board of Family Medicine.

  11. The unethical focus on access: a study of medical ethics and the waiting-time guarantee.

    PubMed

    Karlberg, H I; Brinkmo, B-M

    2009-03-01

    All civilized societies favour ethical principles of equity. In healthcare, these principles generally focus on needs for medical care. Methods for establishing priorities among such needs are instrumental in this process. In this study, we analysed whether rules on access to healthcare, waiting-time guarantees, conflict with ethical principles of distributive justice. We interviewed directors, managers and other decision-makers of various healthcare providers of hospitals, primary care organizations and purchasing offices. We also conducted focus group interviews with professionals from a number of distinct medical areas. Our informants and their co-workers were reasonably familiar with the ethical platforms for priority-setting established by the Swedish parliament, giving the sickest patients complete priority. However, to satisfy the waiting-time guarantees, the informants often had to make priority decisions contrary to the ethical principles by favouring access before needs to keep waiting times within certain limits. The common opinion was that the waiting-time guarantee leads to crowding-out effects, overruling the ethical principles based on needs. For more than a decade, the interpretation in Sweden of the equitable principle based on medical needs has been distorted through political decisions, leading to healthcare providers giving priority to access rather than needs for care.

  12. Development of an international research agenda for adult congenital heart disease nursing.

    PubMed

    Goossens, Eva; Fleck, Desiree; Canobbio, Mary M; Harrison, Jeanine L; Moons, Philip

    2013-02-01

    Since the population of adults with congenital heart disease (CHD) is growing, the role of nurse specialists is expanding. In order to advance ACHD nursing, the establishment of an international nursing research agenda is recommended. We aimed to investigate research priorities as perceived by nurse specialists and researchers in ACHD. We applied a sequential quan-qual design. In the quantitative phase, a two-round Delphi study was conducted, in which 37 nurse specialists and nurse researchers in ACHD care participated. Respondents assessed the level of priority of 21 research topics using a 9-point rating scale (1 = no priority at all; 9 = very high priority). In the qualitative phase, semi-structured interviews were performed with six selected Delphi panelists, to scrutinize pending research questions. This study revealed that priority should be given to studies investigating knowledge and education of patients, outcomes of Advanced Practice Nursing, quality of life, transfer and transition, and illness experiences and psychosocial issues in adults with CHD. A low priority was given to post-operative pain, sexual functioning, transplantation in ACHD, and health care costs and utilization. Agreement about the level of priority was obtained for 14 out of 21 research topics. Based on this study, we could develop an international research agenda for ACHD. Researchers ought to focus on these areas of highest priority, in order to expand and strengthen the body of knowledge in ACHD nursing.

  13. 75 FR 8854 - Teacher Incentive Fund Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-26

    ...The Secretary of Education (Secretary) proposes priorities, requirements, definitions, and selection criteria under the Teacher Incentive Fund (TIF) program. These proposed priorities, requirements, definitions, and selection criteria are designed to be used in two separate and distinct TIF grant competitions: The Main TIF competition, which will provide TIF funding to eligible entities to support their implementation of performance-based compensation systems (PBCSs) in accordance with the priorities, the Main TIF requirements, the definitions, and the selection criteria proposed in this document, and the TIF Evaluation competition, which will provide, in accordance with the priorities, the Main TIF requirements, the definitions, and the selection criteria as well as the Evaluation requirements proposed in this document, TIF funding to help pay for the costs of implementing these eligible entities' PBCS in exchange for an agreement to participate in the national evaluation. The Secretary may use these proposed TIF priorities, requirements, definitions, and selection criteria in fiscal year (FY) 2010 and subsequent years. We intend the proposed priorities, requirements, definitions, and selection criteria to improve student achievement in high-need schools by creating incentives for effective teachers and principals in these schools.

  14. [Priority pollutants ranking and screening of coke industry based on USEtox model].

    PubMed

    Hao, Tian; Du, Peng-Fei; Du, Bin; Zeng, Si-Yu

    2014-01-01

    Thesis aims at evaluating and setting priority to human toxicity and ecotoxicity of coking pollutants. A field research and sampling project are conducted in coke plant in Shanxi so as to complete the coke emission inventory. The USEtox model representing recommended practice in LCIA characterization is applied to the emission inventory to quantify the potential impacts on human toxicity and ecotoxicity of emerging pollutants. Priority pollutants, production procedures and effects of changing plant site on the toxicity are analyzed. As conclusions, benzo(a) pyrene, benzene, Zn and As are identified as the priority pollutants in human toxicity, while pyrene and anthracene in ecotoxicity. Coal charging is the dominant procedure for organic toxicity and priority pollutants include benzo (a) pyrene, benzene, naphthalene, etc. While coke drenching is the dominant procedure for metal toxicity and priority pollutants include Zn, As, Ti, Hg etc. Emission to rural environment can reduce the organic toxicity significantly compared to the emission to urban environment. However, the site changing has no effect on metal toxicity and might increase the risk of the metal pollution to rural water and soil.

  15. [National and regional prioritisation in Swedish health care: experiences from cardiology].

    PubMed

    Carlsson, Jörg

    2012-01-01

    Prioritisation of medical services in Sweden takes place on two different levels. On the national level, the Swedish priority guidelines ascribe priority values ranging from 1 (high priority) to 10 (low priority) to measures (in terms of condition-treatment pairs) of prevention, diagnosis, treatment and rehabilitation of cardiovascular diseases. In addition, this list contains interventions that should be avoided and those that should only be provided as part of clinical research projects. The government then commissions a multi-professional team under the supervision of the National Board of Health and Welfare "Socialstyelsen" with the development of corresponding guidelines. In addition to the scientific evidence, the priority lists incorporate ethical and economical aspects and are based on the so-called ethics platform consisting of human dignity, needs, solidarity and cost-effectiveness. At the other level of prioritisation there are regional projects aiming at the in- and exclusion of medical measures. The Swedish prioritisation process will be described using the example of priority lists in cardiology. (As supplied by publisher). Copyright © 2012. Published by Elsevier GmbH.

  16. Balancing efficiency, equity and feasibility of HIV treatment in South Africa – development of programmatic guidance

    PubMed Central

    2013-01-01

    South Africa, the country with the largest HIV epidemic worldwide, has been scaling up treatment since 2003 and is rapidly expanding its eligibility criteria. The HIV treatment programme has achieved significant results, and had 1.8 million people on treatment per 2011. Despite these achievements, it is now facing major concerns regarding (i) efficiency: alternative treatment policies may save more lives for the same budget; (ii) equity: there are large inequalities in who receives treatment; (iii) feasibility: still only 52% of the eligible population receives treatment. Hence, decisions on the design of the present HIV treatment programme in South Africa can be considered suboptimal. We argue there are two fundamental reasons to this. First, while there is a rapidly growing evidence-base to guide priority setting decisions on HIV treatment, its included studies typically consider only one criterion at a time and thus fail to capture the broad range of values that stakeholders have. Second, priority setting on HIV treatment is a highly political process but it seems no adequate participatory processes are in place to incorporate stakeholders’ views and evidences of all sorts. We propose an alternative approach that provides a better evidence base and outlines a fair policy process to improve priority setting in HIV treatment. The approach integrates two increasingly important frameworks on health care priority setting: accountability for reasonableness (A4R) to foster procedural fairness, and multi-criteria decision analysis (MCDA) to construct an evidence-base on the feasibility, efficiency, and equity of programme options including trade-offs. The approach provides programmatic guidance on the choice of treatment strategies at various decisions levels based on a sound conceptual framework, and holds large potential to improve HIV priority setting in South Africa. PMID:24107435

  17. [Hydrotherapy equipment].

    PubMed

    Tsibikov, V B; Ragozin, S I; Mikheeva, L V

    1985-01-01

    A flow-chart is developed demonstrating the relation between medical and prophylactic institutions within the organizational structure of the rehabilitation system and main types of rehabilitation procedures. In order to ascertain the priority in equipping rehabilitation services with adequate hardware the special priority criterion is introduced. The highest priority is assigned to balneotherapeutic and fangotherapeutic services. Based on the operation-by-operation analysis of clinical processes related to service and performance of balneologic procedures the preliminary set of clinical devices designed for baths, basins and showers in hospitals and rehabilitation departments is defined in a generalized form.

  18. Physical Sciences Research Priorities and Plans in OBPR

    NASA Technical Reports Server (NTRS)

    Trinh, Eugene

    2002-01-01

    This paper presents viewgraphs of physical sciences research priorities and plans at the Office of Biological and Physical Sciences Research (OBPR). The topics include: 1) Sixth Microgravity Fluid Physics and Transport Phenomena Conference; 2) Beneficial Characteristics of the Space Environment; 3) Windows of Opportunity for Research Derived from Microgravity; 4) Physical Sciences Research Program; 5) Fundamental Research: Space-based Results and Ground-based Applications; 6) Nonlinear Oscillations; and 7) Fundamental Research: Applications to Mission-Oriented Research.

  19. Scheduling with hop-by-hop priority increasing in meshed optical burst-switched network

    NASA Astrophysics Data System (ADS)

    Chang, Hao; Luo, Jiangtao; Zhang, Zhizhong; Xia, Da; Gong, Jue

    2006-09-01

    In OBS, JET (Just-Enough-Time) is the classical wavelength reservation scheme. But there is a phenomenon that the burst priority decreasing hop-by-hop in multi-hop networks that will waste the bandwidth that was used in the upstream. Based on the HPI (Hop-by-hop Priority Increasing) proposed in the former research, this paper will do an unprecedented simulation in 4×4 meshed topology, which is closer to the real network environment with the help of a NS2-based OBSN simulation platform constructed by ourselves. By contrasting, the drop probability and throughput on one of the longest end-to-end path lengths in the whole networks, it shows that the HPI scheme can improve the utilance of bandwidth better.

  20. Priorities to Advance Monitoring of Ecosystem Services Using Earth Observation.

    PubMed

    Cord, Anna F; Brauman, Kate A; Chaplin-Kramer, Rebecca; Huth, Andreas; Ziv, Guy; Seppelt, Ralf

    2017-06-01

    Managing ecosystem services in the context of global sustainability policies requires reliable monitoring mechanisms. While satellite Earth observation offers great promise to support this need, significant challenges remain in quantifying connections between ecosystem functions, ecosystem services, and human well-being benefits. Here, we provide a framework showing how Earth observation together with socioeconomic information and model-based analysis can support assessments of ecosystem service supply, demand, and benefit, and illustrate this for three services. We argue that the full potential of Earth observation is not yet realized in ecosystem service studies. To provide guidance for priority setting and to spur research in this area, we propose five priorities to advance the capabilities of Earth observation-based monitoring of ecosystem services. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Comparison of neuronal spike exchange methods on a Blue Gene/P supercomputer.

    PubMed

    Hines, Michael; Kumar, Sameer; Schürmann, Felix

    2011-01-01

    For neural network simulations on parallel machines, interprocessor spike communication can be a significant portion of the total simulation time. The performance of several spike exchange methods using a Blue Gene/P (BG/P) supercomputer has been tested with 8-128 K cores using randomly connected networks of up to 32 M cells with 1 k connections per cell and 4 M cells with 10 k connections per cell, i.e., on the order of 4·10(10) connections (K is 1024, M is 1024(2), and k is 1000). The spike exchange methods used are the standard Message Passing Interface (MPI) collective, MPI_Allgather, and several variants of the non-blocking Multisend method either implemented via non-blocking MPI_Isend, or exploiting the possibility of very low overhead direct memory access (DMA) communication available on the BG/P. In all cases, the worst performing method was that using MPI_Isend due to the high overhead of initiating a spike communication. The two best performing methods-the persistent Multisend method using the Record-Replay feature of the Deep Computing Messaging Framework DCMF_Multicast; and a two-phase multisend in which a DCMF_Multicast is used to first send to a subset of phase one destination cores, which then pass it on to their subset of phase two destination cores-had similar performance with very low overhead for the initiation of spike communication. Departure from ideal scaling for the Multisend methods is almost completely due to load imbalance caused by the large variation in number of cells that fire on each processor in the interval between synchronization. Spike exchange time itself is negligible since transmission overlaps with computation and is handled by a DMA controller. We conclude that ideal performance scaling will be ultimately limited by imbalance between incoming processor spikes between synchronization intervals. Thus, counterintuitively, maximization of load balance requires that the distribution of cells on processors should not reflect neural net architecture but be randomly distributed so that sets of cells which are burst firing together should be on different processors with their targets on as large a set of processors as possible.

  2. Simultaneous polarization-insensitive phase-space trans-multiplexing and wavelength multicasting via cross-phase modulation in a photonic crystal fiber at 10 GBd

    NASA Astrophysics Data System (ADS)

    Cannon, Brice M.

    This thesis investigates the all-optical combination of amplitude and phase modulated signals into one unified multi-level phase modulated signal, utilizing the Kerr nonlinearity of cross-phase modulation (XPM). Predominantly, the first experimental demonstration of simultaneous polarization-insensitive phase-transmultiplexing and multicasting (PI-PTMM) will be discussed. The PI-PTMM operation combines the data of a single 10-Gbaud carrier-suppressed return-to-zero (CSRZ) on-off keyed (OOK) pump signal and 4x10-Gbaud return-to-zero (RZ) binary phase-shift keyed (BPSK) probe signals to generate 4x10-GBd RZ-quadrature phase-shift keyed (QPSK) signals utilizing a highly nonlinear, birefringent photonic crystal fiber (PCF). Since XPM is a highly polarization dependent nonlinearity, a polarization sensitivity reduction technique was used to alleviate the fluctuations due to the remotely generated signals' unpredictable states of polarization (SOP). The measured amplified spontaneous emission (ASE) limited receiver sensitivity optical signal-to-noise ratio (OSNR) penalty of the PI-PTMM signal relative to the field-programmable gate array (FPGA) pre-coded RZ-DQPSK baseline at a forward-error correction (FEC) limit of 10-3 BER was ≈ 0.3 dB. In addition, the OSNR of the remotely generated CSRZ-OOK signal could be degraded to ≈ 29 dB/0.1nm, before the bit error rate (BER) performance of the PI-PTMM operation began to exponentially degrade. A 138-km dispersion-managed recirculating loop system with a 100-GHz, 13-channel mixed-format dense-wavelength-division multiplexed (DWDM) transmitter was constructed to investigate the effect of metro/long-haul transmission impairments. The PI-PTMM DQPSK and the FPGA pre-coded RZ-DQPSK baseline signals were transmitted 1,900 km and 2,400 km in the nonlinearity-limited transmission regime before reaching the 10-3 BER FEC limit. The relative reduction in transmission distance for the PI-PTMM signal was due to the additional transmitter impairments in the PCF that interact negatively with the transmission fiber.

  3. Setting priorities for safe motherhood programme evaluation: a participatory process in three developing countries.

    PubMed

    Madi, Banyana Cecilia; Hussein, Julia; Hounton, Sennen; D'Ambruoso, Lucia; Achadi, Endang; Arhinful, Daniel Kojo

    2007-09-01

    A participatory approach to priority setting in programme evaluation may help improve the allocation and more efficient use of scarce resources especially in low-income countries. Research agendas that are the result of collaboration between researchers, programme managers, policy makers and other stakeholders have the potential to ensure rigorous studies are conducted on matters of local priority, based on local, expert knowledge. This paper describes a process involving key stakeholders to elicit and prioritise evaluation needs for safe motherhood in three developing countries. A series of reiterative consultations with safe motherhood stakeholders from each country was conducted over a period of 36 months. In each country, the consultation process consisted of a series of participatory workshops; firstly, stakeholder's views on evaluation were elicited with parallel descriptive work on the contexts. Secondly, priorities for evaluation were identified from stakeholders; thirdly, the evaluation-priorities were refined; and finally, the evaluation research questions, reflecting the identified priorities, were agreed and finalised. Three evaluation-questions were identified in each country, and one selected, on which a full scale evaluation was undertaken. While there is a great deal written about the importance of transparent and participatory priority setting in evaluation; few examples of how such processes could be implemented exist, particularly for maternal health programmes. Our experience demonstrates that the investment in a participatory priority-setting effort is high but the process undertaken resulted in both globally and contextually-relevant priorities for evaluation. This experience provides useful lessons for public health practitioners committed to bridging the research-policy interface.

  4. What do District Health Planners in Tanzania think about improving priority setting using 'Accountability for Reasonableness'?

    PubMed Central

    Mshana, Simon; Shemilu, Haji; Ndawi, Benedict; Momburi, Roman; Olsen, Oystein Evjen; Byskov, Jens; Martin, Douglas K

    2007-01-01

    Background Priority setting in every health system is complex and difficult. In less wealthy countries the dominant approach to priority setting has been Burden of Disease (BOD) and cost-effectiveness analysis (CEA), which is helpful, but insufficient because it focuses on a narrow range of values – need and efficiency – and not the full range of relevant values, including legitimacy and fairness. 'Accountability for reasonableness' is a conceptual framework for legitimate and fair priority setting and is empirically based and ethically justified. It connects priority setting to broader, more fundamental, democratic deliberative processes that have an impact on social justice and equity. Can 'accountability for reasonableness' be helpful for improving priority setting in less wealthy countries? Methods In 2005, Tanzanian scholars from the Primary Health Care Institute (PHCI) conducted 6 capacity building workshops with senior health staff, district planners and managers, and representatives of the Tanzanian Ministry of Health to discussion improving priority setting in Tanzania using 'accountability for reasonableness'. The purpose of this paper is to describe this initiative and the participants' views about the approach. Results The approach to improving priority setting using 'accountability for reasonableness' was viewed by district decision makers with enthusiastic favour because it was the first framework that directly addressed their priority setting concerns. High level Ministry of Health participants were also very supportive of the approach. Conclusion Both Tanzanian district and governmental health planners viewed the 'accountability for reasonableness' approach with enthusiastic favour because it was the first framework that directly addressed their concerns. PMID:17997824

  5. What Should We Teach the Teachers? Identifying the Learning Priorities of Clinical Supervisors

    ERIC Educational Resources Information Center

    Bearman, Margaret; Tai, Joanna; Kent, Fiona; Edouard, Vicki; Nestel, Debra; Molloy, Elizabeth

    2018-01-01

    Clinicians who teach are essential for the health workforce but require faculty development to improve their educational skills. Curricula for faculty development programs are often based on expert frameworks without consideration of the learning priorities as defined by clinical supervisors themselves. We sought to inform these curricula by…

  6. 14 CFR 250.9 - Written explanation of denied boarding compensation and boarding priorities.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... of air carrier), you are probably entitled to monetary compensation. This notice explains the airline... of (name of air carrier): (In this space the carrier inserts its boarding priority rules or a summary... compensation is based shall include any surcharge and air transportation tax. “Alternate transportation” is air...

  7. 78 FR 60966 - Self-Regulatory Organizations: Miami International Securities Exchange LLC; Notice of Filing and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-02

    .... As such, marketing fee programs,\\7\\ and customer posting incentive programs,\\8\\ are based on... its current Priority Customer Rebate Program (the ``Program'') until October 31, 2013.\\3\\ The Program... Priority Customer \\6\\ order transmitted by that Member which is executed on the Exchange in all multiply...

  8. 77 FR 24934 - Proposed Priority-National Institute on Disability and Rehabilitation Research-Disability and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-26

    ... the stage of research being proposed and the methods appropriate to that stage. Through this priority... observational findings, and creating other sources of research-based information. This research stage may... provide a rationale for the stage of research being proposed and the research methods associated with the...

  9. Annual Report on LSCA Priorities. FY 1982.

    ERIC Educational Resources Information Center

    Office of Educational Research and Improvement (ED), Washington, DC. Center for Libraries and Education Improvement.

    This collection of six reports was compiled by the State and Public Library Services Branch of the United States Department of Education to disseminate pertinent information submitted by the State Library Administrative Agencies on the Library Services and Construction Act (LSCA) priority areas. Based on data from the fiscal year 1982 LSCA Annual…

  10. 77 FR 70451 - Report of the Evidence-Based Methodology Workshop on Polycystic Ovary Syndrome-Request for Comments

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-26

    ..., 2012. The purpose of the report is to summarize the workshop and identify future research priorities... the workshop agenda. The NIH Library created an extensive, descriptive bibliography on PCOS to... the workshop and identifies future research priorities. The report will be available online beginning...

  11. 34 CFR 222.189 - What funding priority does the Secretary give to applications?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... OFFICE OF ELEMENTARY AND SECONDARY EDUCATION, DEPARTMENT OF EDUCATION IMPACT AID PROGRAMS Impact Aid..., priority is given to applications based on a rank order of the application quality factors referenced in... application quality factors referenced in § 222.190, including the severity of the emergency. (3) Third...

  12. 34 CFR 222.189 - What funding priority does the Secretary give to applications?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... OFFICE OF ELEMENTARY AND SECONDARY EDUCATION, DEPARTMENT OF EDUCATION IMPACT AID PROGRAMS Impact Aid..., priority is given to applications based on a rank order of the application quality factors referenced in... application quality factors referenced in § 222.190, including the severity of the emergency. (3) Third...

  13. 34 CFR 222.189 - What funding priority does the Secretary give to applications?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... OFFICE OF ELEMENTARY AND SECONDARY EDUCATION, DEPARTMENT OF EDUCATION IMPACT AID PROGRAMS Impact Aid..., priority is given to applications based on a rank order of the application quality factors referenced in... application quality factors referenced in § 222.190, including the severity of the emergency. (3) Third...

  14. Innovative Problems of Improving the Quality of Life of the Welfare State

    ERIC Educational Resources Information Center

    Panachev, Valery D.

    2016-01-01

    Improvement of the population quality of life should be based on promoting healthy lifestyle, active physical exercises and sports activities as one of its main priorities. In order to facilitate the achievement of this priority, the author proposes management technique of complicated coordination movements in space in the development of…

  15. 44 CFR 152.5 - Review process and evaluation criteria.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... criteria and the program priorities. Eligible applicants that best address the priorities will advance to a... Review process and evaluation criteria. (a) Every application will be evaluated based on the answers to... screening will be in the “competitive range” and subject to a second level of review. We will use the...

  16. Aid alignment: a longer term lens on trends in development assistance for health in Uganda

    PubMed Central

    2013-01-01

    Background Over the past decade, development assistance for health (DAH) in Uganda has increased dramatically, surpassing the government’s own expenditures on health. Yet primary health care and other priorities identified in Uganda’s health sector strategic plan remain underfunded. Methods Using data available from the Creditor Reporting System (CRS), National Health Accounts (NHA), and government financial reports, we examined trends in how donors channel DAH and the extent to which DAH is aligned with sector priorities. The study follows the flow of DAH from the donor to the implementing organization, specifying the modality used for disbursing funds and categorizing funds based on program area or support function. Findings Despite efforts to improve alignment through the formation of a sector-wide approach (SWAp) for health in 1999 and the creation of a fund to pool resources for identified priorities, increasingly DAH is provided as short-term, project-based support for disease-specific initiatives, in particular HIV/AIDS. Conclusion These findings highlight the need to better align external resources with country priorities and refocus attention on longer-term sector-wide objectives. PMID:23425287

  17. Priority setting in health care: trends and models from Scandinavian experiences.

    PubMed

    Hofmann, Bjørn

    2013-08-01

    The Scandinavian welfare states have public health care systems which have universal coverage and traditionally low influence of private insurance and private provision. Due to raises in costs, elaborate public control of health care, and a significant technological development in health care, priority setting came on the public agenda comparatively early in the Scandinavian countries. The development of health care priority setting has been partly homogeneous and appears to follow certain phases. This can be of broader interest as it may shed light on alternative models and strategies in health care priority setting. Some general trends have been identified: from principles to procedures, from closed to open processes, and from experts to participation. Five general approaches have been recognized: The moral principles and values based approach, the moral principles and economic assessment approach, the procedural approach, the expert based practice defining approach, and the participatory practice defining approach. There are pros and cons with all of these approaches. For the time being the fifth approach appears attractive, but its lack of true participation and the lack of clear success criteria may pose significant challenges in the future.

  18. Performance Optimization of Priority Assisted CSMA/CA Mechanism of 802.15.6 under Saturation Regime

    PubMed Central

    Shakir, Mustafa; Rehman, Obaid Ur; Rahim, Mudassir; Alrajeh, Nabil; Khan, Zahoor Ali; Khan, Mahmood Ashraf; Niaz, Iftikhar Azim; Javaid, Nadeem

    2016-01-01

    Due to the recent development in the field of Wireless Sensor Networks (WSNs), the Wireless Body Area Networks (WBANs) have become a major area of interest for the developers and researchers. Human body exhibits postural mobility due to which distance variation occurs and the status of connections amongst sensors change time to time. One of the major requirements of WBAN is to prolong the network lifetime without compromising on other performance measures, i.e., delay, throughput and bandwidth efficiency. Node prioritization is one of the possible solutions to obtain optimum performance in WBAN. IEEE 802.15.6 CSMA/CA standard splits the nodes with different user priorities based on Contention Window (CW) size. Smaller CW size is assigned to higher priority nodes. This standard helps to reduce delay, however, it is not energy efficient. In this paper, we propose a hybrid node prioritization scheme based on IEEE 802.15.6 CSMA/CA to reduce energy consumption and maximize network lifetime. In this scheme, optimum performance is achieved by node prioritization based on CW size as well as power in respective user priority. Our proposed scheme reduces the average back off time for channel access due to CW based prioritization. Additionally, power based prioritization for a respective user priority helps to minimize required number of retransmissions. Furthermore, we also compare our scheme with IEEE 802.15.6 CSMA/CA standard (CW assisted node prioritization) and power assisted node prioritization under postural mobility in WBAN. Mathematical expressions are derived to determine the accurate analytical model for throughput, delay, bandwidth efficiency, energy consumption and life time for each node prioritization scheme. With the intention of analytical model validation, we have performed the simulations in OMNET++/MIXIM framework. Analytical and simulation results show that our proposed hybrid node prioritization scheme outperforms other node prioritization schemes in terms of average network delay, average throughput, average bandwidth efficiency and network lifetime. PMID:27598167

  19. Norepinephrine ignites local hot spots of neuronal excitation: How arousal amplifies selectivity in perception and memory

    PubMed Central

    Mather, Mara; Clewett, David; Sakaki, Michiko; Harley, Carolyn W.

    2018-01-01

    Long Abstract Existing brain-based emotion-cognition theories fail to explain arousal’s ability to both enhance and impair cognitive processing. In the Glutamate Amplifies Noradrenergic Effects (GANE) model outlined in this paper, we propose that arousal-induced norepinephrine (NE) released from the locus coeruleus (LC) biases perception and memory in favor of salient, high priority representations at the expense of lower priority representations. This increase in gain under phasic arousal occurs via synaptic self-regulation of NE based on glutamate levels. When the LC is phasically active, elevated levels of glutamate at the site of prioritized representations increase local NE release, creating “NE hot spots.” At these local hot spots, glutamate and NE release are mutually enhancing and amplify activation of prioritized representations. This excitatory effect contrasts with widespread NE suppression of weaker representations via lateral and auto-inhibitory processes. On a broader scale, hot spots increase oscillatory synchronization across neural ensembles transmitting high priority information. Furthermore, key brain structures that detect or pre-determine stimulus priority interact with phasic NE release to preferentially route such information through large-scale functional brain networks. A surge of NE before, during or after encoding enhances synaptic plasticity at sites of high glutamate activity, triggering local protein synthesis processes that enhance selective memory consolidation. Together, these noradrenergic mechanisms increase perceptual and memory selectivity under arousal. Beyond explaining discrepancies in the emotion-cognition literature, GANE reconciles and extends previous influential theories of LC neuromodulation by highlighting how NE can produce such different outcomes in processing based on priority. PMID:26126507

  20. Communicating laboratory results through a Web site: Patients' priorities and viewpoints.

    PubMed

    Sabahi, Azam; Ahmadian, Leila; Mirzaee, Moghademeh

    2018-02-28

    Patients can access laboratory results using various technologies. The aim of this study was to integrate the laboratory results into the hospital Web site based on patients' viewpoints and priorities and to measure patients' satisfaction. This descriptive-analytical study was conducted in 2015. First, a questionnaire was distributed among 200 patients to assess patients' priorities to receive laboratory results through the Web site. Second, those who agreed (n = 95) to receive their laboratory results through the Web site were identified. Then, the required changes were made to the hospital Web site based on patients' viewpoints and priorities. Third, patients were divided into two groups. The first group received their laboratory results through the Web site on the date had been announced during their visit to the laboratory. The second group was informed by SMS once their results were shown on the Web site. After receiving laboratory results, patients' satisfaction was evaluated. More than half of the participants (n = 53, 55.8%) were highly satisfied with receiving the results electronically. The higher number of people in SMS group (n = 9, 20.9%) reported that they were satisfied with time-saving compared to other group (n = 2, 3.8%) (P = .04). Participants after receiving the results through the Web site considered the functionalities of reprinting (P < .0001) and timeliness (P = .017) more important. Integrating laboratory results into the hospital Web site based on the patients' viewpoints and priorities can improve patient satisfaction and lower the patients' concern regarding confidentiality of their results. © 2018 Wiley Periodicals, Inc.

  1. Research priorities for specialized nursing practice in the United Arab Emirates.

    PubMed

    Al-Yateem, N; Al-Tamimi, M; Brenner, M; Altawil, H; Ahmad, A; Brownie, S

    2017-08-25

    Globally, nurses are undertaking expanded and more specialized roles in healthcare planning and service delivery in response to changing patterns and levels of health service demand. This means the nursing profession is increasingly considered as leaders in health service policy, research and practice. The United Arab Emirates has strengthened nursing governance and practice by establishing a Nursing and Midwifery Council and increasing the activity of nursing specialization, service leadership and research. This study aimed to identify clinically relevant research priorities to facilitate nursing contributions to evidence-based care and strengthening health services in the country. A two-stage Delphi study design was used. The first round involved 783 participants. The second round involved 1116 participants, as more clinical settings were accessed. In total, 58 research priorities across a variety of nursing specialties (paediatrics, emergency care, intensive care, labour and maternity care, operating theatre and long-term care) were identified as highly important. These identified priorities will guide a more informed programme of research in each nursing specialty, with the aim of strengthening the evidence base to improving outcomes for patients and their families in the United Arab Emirates. The findings provide guidance on key areas for nurses to focus research contributions to enhance evidence-based care and strengthen health systems. The identified priorities may also guide researchers in academic institutions to conduct research informed by current, clinically relevant issues. The findings may help inform funders and policymakers to support allocation of funding to research that has potential to contribute to enhancing nursing care in specialist areas. © 2017 International Council of Nurses.

  2. Pediatric Emergency Research Canada (PERC): Patient/Family-Informed Research Priorities for Pediatric Emergency Medicine.

    PubMed

    Bialy, Liza; Plint, Amy C; Freedman, Stephen B; Johnson, David W; Curran, Janet A; Stang, Antonia S

    2018-06-06

    A growing body of literature supports patient and public involvement in the design, prioritization and dissemination of research and evidence based medicine. The objectives of this project were to engage patients and families in developing a prioritized list of research topics for Pediatric Emergency Medicine (PEM) and to compare results with prior research prioritization initiatives in the ED (emergency department) setting. We utilized a systematic process to combine administrative data on frequency of patient presentations to the ED with multiple stakeholder input including an initial stakeholder survey followed by a modified Delphi consensus methodology consisting of two web-based surveys and a face-to-face meeting. The prioritization process resulted in a ranked list of 15 research priorities. The top five priorities were mental health presentations, pain and sedation, practice tools, quality of care delivery and resource utilization. Mental health, pain and sedation, clinical prediction rules, respiratory illnesses /wheeze, patient safety/medication error and sepsis were identified as shared priorities with prior initiatives. Topics identified in our process that were not identified in prior work included resource utilization, ED communication, antibiotic stewardship and patient/family adherence with recommendations. This work identifies key priorities for research in PEM. Comparing our results with prior initiatives in the ED setting identified shared research priorities and opportunities for collaboration among PEM research networks. This work in particular makes an important contribution to the existing literature by including the patient/family perspective missing from prior work. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  3. Delphi Survey of Clinical Nursing and Midwifery Research Priorities in the Eastern Mediterranean Region.

    PubMed

    Sun, Carolyn; Dohrn, Jennifer; Oweis, Arwa; Huijer, Huda Abu-Saad; Abu-Moghli, Fathieh; Dawani, Hania; Ghazi, Cheherezade; Larson, Elaine

    2017-03-01

    As the shortage of nurses and midwives is expected to worsen in the Eastern Mediterranean region concomitantly with a growing focus on achievement of universal health coverage, nurses and midwives are expected to fill major gaps in health care. Hence, the need for a solid evidence base for nursing practice and a clear direction for clinical nursing research are paramount. Therefore, a Delphi survey was conducted to determine clinical (research focused on patient outcomes) nursing and midwifery priorities for research within this region. A Delphi survey, using iterative rounds of an online survey of regional clinical nursing and midwifery research experts, was conducted between January and April 2016. Consensus was determined by percentage agreement on level of priority for topics as determined by participants. Additionally, results were compared between countries within the region by income and mortality levels using Kendall's tau. Critical research topics were focused on public/community/primary care as well as emergency preparedness for disasters, and these priorities are well aligned with gaps in the literature for this region. There were statistically significant differences between priority level and country mortality group for geriatrics, self-management of disease, and sexually transmitted infections. Critical research priorities should focus on population-based health topics. Between-country differences should be analyzed further. A clinical research database for the region may help improve research access for nurses and midwives. Practicing nurses and midwives lack extensive evidence (including culturally relevant evidence) on which to practice. Increasing research in areas identified in this survey may improve patient outcomes and quality of care regionally. © 2017 Sigma Theta Tau International.

  4. Discovery, research, and development of new antibiotics: the WHO priority list of antibiotic-resistant bacteria and tuberculosis.

    PubMed

    Tacconelli, Evelina; Carrara, Elena; Savoldi, Alessia; Harbarth, Stephan; Mendelson, Marc; Monnet, Dominique L; Pulcini, Céline; Kahlmeter, Gunnar; Kluytmans, Jan; Carmeli, Yehuda; Ouellette, Marc; Outterson, Kevin; Patel, Jean; Cavaleri, Marco; Cox, Edward M; Houchens, Chris R; Grayson, M Lindsay; Hansen, Paul; Singh, Nalini; Theuretzbacher, Ursula; Magrini, Nicola

    2018-03-01

    The spread of antibiotic-resistant bacteria poses a substantial threat to morbidity and mortality worldwide. Due to its large public health and societal implications, multidrug-resistant tuberculosis has been long regarded by WHO as a global priority for investment in new drugs. In 2016, WHO was requested by member states to create a priority list of other antibiotic-resistant bacteria to support research and development of effective drugs. We used a multicriteria decision analysis method to prioritise antibiotic-resistant bacteria; this method involved the identification of relevant criteria to assess priority against which each antibiotic-resistant bacterium was rated. The final priority ranking of the antibiotic-resistant bacteria was established after a preference-based survey was used to obtain expert weighting of criteria. We selected 20 bacterial species with 25 patterns of acquired resistance and ten criteria to assess priority: mortality, health-care burden, community burden, prevalence of resistance, 10-year trend of resistance, transmissibility, preventability in the community setting, preventability in the health-care setting, treatability, and pipeline. We stratified the priority list into three tiers (critical, high, and medium priority), using the 33rd percentile of the bacterium's total scores as the cutoff. Critical-priority bacteria included carbapenem-resistant Acinetobacter baumannii and Pseudomonas aeruginosa, and carbapenem-resistant and third-generation cephalosporin-resistant Enterobacteriaceae. The highest ranked Gram-positive bacteria (high priority) were vancomycin-resistant Enterococcus faecium and meticillin-resistant Staphylococcus aureus. Of the bacteria typically responsible for community-acquired infections, clarithromycin-resistant Helicobacter pylori, and fluoroquinolone-resistant Campylobacter spp, Neisseria gonorrhoeae, and Salmonella typhi were included in the high-priority tier. Future development strategies should focus on antibiotics that are active against multidrug-resistant tuberculosis and Gram-negative bacteria. The global strategy should include antibiotic-resistant bacteria responsible for community-acquired infections such as Salmonella spp, Campylobacter spp, N gonorrhoeae, and H pylori. World Health Organization. Copyright © 2018 Elsevier Ltd. All rights reserved.

  5. Identifying research priorities with nurses at a tertiary children's hospital in the United Kingdom.

    PubMed

    Williams, A; Sell, D; Oulton, K; Wilson, N; Wray, J; Gibson, F

    2017-03-01

    The objective of this study was to undertake a research priority setting exercise with the aim of maximizing efficiency and impact in research activity undertaken by nurses at one children's tertiary healthcare institution by ensuring the clinical staff directly shaped a coherent, transparent and consensus driven nurse-led research agenda. In Round 1, the research topics of 147 nurses were elicited using a modified nominal group technique as the consensus method. The number of participants in the 24 separate discussions ranged from 3 to 21, generating lists of between 6 and 23 topics. In Round 2, nurses from the clinical areas ranked topics of importance resulting in a set of four to five priorities. In Round 3, the divisional heads of nursing consulted with staff in all of their clinical areas to each finalize their five divisional priorities. The Nursing Research Working Group discussed and refined the divisions' priorities and voted on the final list to agree the top five research priorities for the organization. A total of 269 research topics were initially generated. Following three rounds of ranking and prioritizing, five priorities were agreed at Divisional level, and from these, the five top organizational priorities were selected. These were (i) understanding and improving all aspects of the patient journey through the hospital system; (ii) play; (iii) staff wellbeing, patient care and productivity; (iv) team work - linking to a more efficient service; and (v) supporting parents/parent pathway. Divisional priorities have been disseminated widely to clinical teams to inform a patient-specific nurse-led research agenda. Organizational priorities agreed upon have been disseminated through management structures and processes to ensure engagement at all levels. A subgroup of the Nursing Research Working Group has been delegated to take this work forward so that the agreed priorities continue to contribute towards shaping nurse-led research activity, thereby going some way to inform and embed an evidence-based culture of inquiry. © 2016 John Wiley & Sons Ltd.

  6. Dynamic Hop Service Differentiation Model for End-to-End QoS Provisioning in Multi-Hop Wireless Networks

    NASA Astrophysics Data System (ADS)

    Youn, Joo-Sang; Seok, Seung-Joon; Kang, Chul-Hee

    This paper presents a new QoS model for end-to-end service provisioning in multi-hop wireless networks. In legacy IEEE 802.11e based multi-hop wireless networks, the fixed assignment of service classes according to flow's priority at every node causes priority inversion problem when performing end-to-end service differentiation. Thus, this paper proposes a new QoS provisioning model called Dynamic Hop Service Differentiation (DHSD) to alleviate the problem and support effective service differentiation between end-to-end nodes. Many previous works for QoS model through the 802.11e based service differentiation focus on packet scheduling on several service queues with different service rate and service priority. Our model, however, concentrates on a dynamic class selection scheme, called Per Hop Class Assignment (PHCA), in the node's MAC layer, which selects a proper service class for each packet, in accordance with queue states and service requirement, in every node along the end-to-end route of the packet. The proposed QoS solution is evaluated using the OPNET simulator. The simulation results show that the proposed model outperforms both best-effort and 802.11e based strict priority service models in mobile ad hoc environments.

  7. Diabetes Bingo: Research Prioritization with the Filipino Community

    PubMed Central

    Oculto, Tessie; Ramones, Emilyn; Caagbay, Cedric R

    2010-01-01

    This community-based participatory research, conducted in partnership between a European-American academic researcher and a professional group of Filipino nurses, aimed to determine the diabetes research priority for the Filipino community on the island of O‘ahu in Hawai‘i, and to evaluate the multi-voting technique to seek input from the community. The study design was a qualitative, cross-sectional interactive process consisting of an educational presentation followed by data collection from the audience. Ten community presentations about the impact of diabetes on the Filipino community were conducted by a Filipino nurse with participants (N = 265). Following the educational session, the participants selected priorities for research using a multi-vote technique developed as a Diabetes Bingo card. Community voting results identified prevention and a focus on adults as important priorities for research. Based on the results of the multi-voting, the research partners were able to come to consensus on a research priority area of prevention of type 2 diabetes in adults. Multi-voting using a Diabetes Bingo card, preceded by an educational presentation by a Filipino nurse, was a culturally competent community-based participatory research method that gave voice to the participants and direction to the research partners for future projects. The multi-voting technique was readily accepted and enjoyed by participants. PMID:21229487

  8. 77 FR 74407 - Proposed Priorities, Requirements, Definitions, and Selection Criteria-Investing in Innovation Fund

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-14

    ...The Assistant Deputy Secretary for Innovation and Improvement proposes priorities, requirements, definitions, and selection criteria under the Investing in Innovation Fund (i3). The Assistant Deputy Secretary may use these priorities, requirements, definitions, and selection criteria for competitions in fiscal year (FY) 2013 and later years. The U.S. Department of Education (Department) has conducted three competitions under the i3 program and awarded 92 i3 grants since the program was established under the American Recovery and Reinvestment Act of 2009 (ARRA). These proposed priorities, requirements, definitions, and selection criteria maintain the overall purpose and structure of the i3 program, which is discussed later in this document, and incorporate changes based on specific lessons learned from the first three competitions.

  9. Managing Contention and Timing Constraints in a Real-Time Database System

    DTIC Science & Technology

    1995-01-01

    In order to realize many of these goals, StarBase is constructed on top of RT-Mach, a real - time operating system developed at Carnegie Mellon...University [ll]. StarBase differs from previous RT-DBMS work [l, 2, 31 in that a) it relies on a real - time operating system which provides priority...CPU and resource scheduling pro- vided by tlhe underlying real - time operating system . Issues of data contention are dealt with by use of a priority

  10. Energy in the Environment - Initiatives 2004-08

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

    Paul Jehn

    Under the Energy and Environment Initiative, the GWPC/GWPRF will expand the oil and gas electronic commerce initiatives used to enhance the Risk Based Data Management System (RBDMS) and the Cost Effective Regulatory Approach (CERA). The GWPC/GWPRF has identified the following priorities for work efforts during the time period that will act as the base from which selections for each work period will be proposed. Work tasks will be presented for each reporting period by the GWPC from areas selected from the general list of priorities.

  11. Phylogenetically-informed priorities for amphibian conservation.

    PubMed

    Isaac, Nick J B; Redding, David W; Meredith, Helen M; Safi, Kamran

    2012-01-01

    The amphibian decline and extinction crisis demands urgent action to prevent further large numbers of species extinctions. Lists of priority species for conservation, based on a combination of species' threat status and unique contribution to phylogenetic diversity, are one tool for the direction and catalyzation of conservation action. We describe the construction of a near-complete species-level phylogeny of 5713 amphibian species, which we use to create a list of evolutionarily distinct and globally endangered species (EDGE list) for the entire class Amphibia. We present sensitivity analyses to test the robustness of our priority list to uncertainty in species' phylogenetic position and threat status. We find that both sources of uncertainty have only minor impacts on our 'top 100' list of priority species, indicating the robustness of the approach. By contrast, our analyses suggest that a large number of Data Deficient species are likely to be high priorities for conservation action from the perspective of their contribution to the evolutionary history.

  12. Communitarian claims and community capabilities: furthering priority setting?

    PubMed

    Mooney, Gavin

    2005-01-01

    Priority setting in health care is generally not done well. This paper draws on ideas from Amartya Sen and Martha Nussbaum and adds some communitarian underpinnings to provide a way of improving on current uses of program budgeting and marginal analysis (PBMA) in priority setting. The paper suggests that shifting to a communitarian base for priority setting alters the distribution of property rights over health service decision making and increases the probability that recommendations from PBMA exercises will be implemented. The approach is built on a paradigm which departs from three tenets of welfarism as it is normally conceived: (i) individuals qua individuals seek to maximise their individual utility/well-being; (ii) individuals want to do this; and (iii) it is the values of individuals qua individuals that count. Some of the problems of PBMA, as it has been applied to date, are highlighted. It is argued that these are due largely to a lack of 'credible commitment'. Bringing in the community and communitarian values to PBMA priority setting exercises can help to overcome some of the barriers to getting PBMA recommendations implemented. The approach has the merit of reflecting Sen's concept of capabilities (but extending that to a community level). It avoids the often consequentialist base of a conventional welfarist framework, and it allows community values as opposed to individual values to come to the fore. How to elicit communitarian values is explored.

  13. Land surface temperature distribution and development for green open space in Medan city using imagery-based satellite Landsat 8

    NASA Astrophysics Data System (ADS)

    Sulistiyono, N.; Basyuni, M.; Slamet, B.

    2018-03-01

    Green open space (GOS) is one of the requirements where a city is comfortable to stay. GOS might reduce land surface temperature (LST) and air pollution. Medan is one of the biggest towns in Indonesia that experienced rapid development. However, the early development tends to neglect the GOS existence for the city. The objective of the study is to determine the distribution of land surface temperature and the relationship between the normalized difference vegetation index (NDVI) and the priority of GOS development in Medan City using imagery-based satellite Landsat 8. The method approached to correlate the distribution of land surface temperature derived from the value of digital number band 10 with the NDVI which was from the ratio of groups five and four on satellite images of Landsat 8. The results showed that the distribution of land surface temperature in the Medan City in 2016 ranged 20.57 - 33.83 °C. The relationship between the distribution of LST distribution with NDVI was reversed with a negative correlation of -0.543 (sig 0,000). The direction of GOS in Medan City is therefore developed on the allocation of LST and divided into three priority classes namely first priority class had 5,119.71 ha, the second priority consisted of 16,935.76 ha, and third priority of 6,118.50 ha.

  14. Enhanced Handover Decision Algorithm in Heterogeneous Wireless Network

    PubMed Central

    Abdullah, Radhwan Mohamed; Zukarnain, Zuriati Ahmad

    2017-01-01

    Transferring a huge amount of data between different network locations over the network links depends on the network’s traffic capacity and data rate. Traditionally, a mobile device may be moved to achieve the operations of vertical handover, considering only one criterion, that is the Received Signal Strength (RSS). The use of a single criterion may cause service interruption, an unbalanced network load and an inefficient vertical handover. In this paper, we propose an enhanced vertical handover decision algorithm based on multiple criteria in the heterogeneous wireless network. The algorithm consists of three technology interfaces: Long-Term Evolution (LTE), Worldwide interoperability for Microwave Access (WiMAX) and Wireless Local Area Network (WLAN). It also employs three types of vertical handover decision algorithms: equal priority, mobile priority and network priority. The simulation results illustrate that the three types of decision algorithms outperform the traditional network decision algorithm in terms of handover number probability and the handover failure probability. In addition, it is noticed that the network priority handover decision algorithm produces better results compared to the equal priority and the mobile priority handover decision algorithm. Finally, the simulation results are validated by the analytical model. PMID:28708067

  15. Basing the US Air Force Special Operations Forces.

    DTIC Science & Technology

    1986-12-01

    rv - _n V - rJ’W J 𔃾r 4-1 . Jr,.,rvru r 1- Jw- Table VIII. Mission and A ...vc a 3 e. ,cr when primarv 3ircraft on his top priority •-re wher ;rimarv aircraft on his 2nd priority r. ’ . rn rv r,-ratt )n his P th priority... A i.’’’’ t.~.- CXX ’ krrar~i .r , r’ , : .- p r" a - , rv "x XX, I’’ " . XX( 37f6-37"’ ",o -sed• *XX 38GC Minimum crew resi in 1,,ur .

  16. Systematic reviews addressing identified health policy priorities in Eastern Mediterranean countries: a situational analysis.

    PubMed

    El-Jardali, Fadi; Akl, Elie A; Karroum, Lama Bou; Kdouh, Ola; Akik, Chaza; Fadlallah, Racha; Hammoud, Rawan

    2014-08-20

    Systematic reviews can offer policymakers and stakeholders concise, transparent, and relevant evidence pertaining to pressing policy priorities to help inform the decision-making process. The production and the use of systematic reviews are specifically limited in the Eastern Mediterranean region. The extent to which published systematic reviews address policy priorities in the region is still unknown. This situational analysis exercise aims at assessing the extent to which published systematic reviews address policy priorities identified by policymakers and stakeholders in Eastern Mediterranean region countries. It also provides an overview about the state of systematic review production in the region and identifies knowledge gaps. We conducted a systematic search of the Health System Evidence database to identify published systematic reviews on policy-relevant priorities pertaining to the following themes: human resources for health, health financing, the role of the non-state sector, and access to medicine. Priorities were identified from two priority-setting exercises conducted in the region. We described the distribution of these systematic reviews across themes, sub-themes, authors' affiliations, and countries where included primary studies were conducted. Out of the 1,045 systematic reviews identified in Health System Evidence on selected themes, a total of 200 systematic reviews (19.1%) addressed the priorities from the Eastern Mediterranean region. The theme with the largest number of systematic reviews included was human resources for health (115) followed by health financing (33), access to medicine (27), and role of the non-state sector (25). Authors based in the region produced only three systematic reviews addressing regional priorities (1.5%). Furthermore, no systematic review focused on the Eastern Mediterranean region. Primary studies from the region had limited contribution to systematic reviews; 17 systematic reviews (8.5%) included primary studies conducted in the region. There are still gaps in the production of systematic reviews addressing policymakers' and stakeholders' priorities in the Eastern Mediterranean region. Efforts should be directed towards better aligning systematic review production with policy needs and priorities. Study findings can inform the agendas of researchers, research institutions, and international funding agencies of priority areas where systematic reviews are required.

  17. How Are New Vaccines Prioritized in Low-Income Countries? A Case Study of Human Papilloma Virus Vaccine and Pneumococcal Conjugate Vaccine in Uganda

    PubMed Central

    Wallace, Lauren; Kapirir, Lydia

    2017-01-01

    Background: To date, research on priority-setting for new vaccines has not adequately explored the influence of the global, national and sub-national levels of decision-making or contextual issues such as political pressure and stakeholder influence and power. Using Kapiriri and Martin’s conceptual framework, this paper evaluates priority setting for new vaccines in Uganda at national and sub-national levels, and considers how global priorities can influence country priorities. This study focuses on 2 specific vaccines, the human papilloma virus (HPV) vaccine and the pneumococcal conjugate vaccine (PCV). Methods: This was a qualitative study that involved reviewing relevant Ugandan policy documents and media reports, as well as 54 key informant interviews at the global level and national and sub-national levels in Uganda. Kapiriri and Martin’s conceptual framework was used to evaluate the prioritization process. Results: Priority setting for PCV and HPV was conducted by the Ministry of Health (MoH), which is considered to be a legitimate institution. While respondents described the priority setting process for PCV process as transparent, participatory, and guided by explicit relevant criteria and evidence, the prioritization of HPV was thought to have been less transparent and less participatory. Respondents reported that neither process was based on an explicit priority setting framework nor did it involve adequate representation from the districts (program implementers) or publicity. The priority setting process for both PCV and HPV was negatively affected by the larger political and economic context, which contributed to weak institutional capacity as well as power imbalances between development assistance partners and the MoH. Conclusion: Priority setting in Uganda would be improved by strengthening institutional capacity and leadership and ensuring a transparent and participatory processes in which key stakeholders such as program implementers (the districts) and beneficiaries (the public) are involved. Kapiriri and Martin’s framework has the potential to guide priority setting evaluation efforts, however, evaluation should be built into the priority setting process a priori such that information on priority setting is gathered throughout the implementation cycle. PMID:29172378

  18. Systematic reviews addressing identified health policy priorities in Eastern Mediterranean countries: a situational analysis

    PubMed Central

    2014-01-01

    Background Systematic reviews can offer policymakers and stakeholders concise, transparent, and relevant evidence pertaining to pressing policy priorities to help inform the decision-making process. The production and the use of systematic reviews are specifically limited in the Eastern Mediterranean region. The extent to which published systematic reviews address policy priorities in the region is still unknown. This situational analysis exercise aims at assessing the extent to which published systematic reviews address policy priorities identified by policymakers and stakeholders in Eastern Mediterranean region countries. It also provides an overview about the state of systematic review production in the region and identifies knowledge gaps. Methods We conducted a systematic search of the Health System Evidence database to identify published systematic reviews on policy-relevant priorities pertaining to the following themes: human resources for health, health financing, the role of the non-state sector, and access to medicine. Priorities were identified from two priority-setting exercises conducted in the region. We described the distribution of these systematic reviews across themes, sub-themes, authors’ affiliations, and countries where included primary studies were conducted. Results Out of the 1,045 systematic reviews identified in Health System Evidence on selected themes, a total of 200 systematic reviews (19.1%) addressed the priorities from the Eastern Mediterranean region. The theme with the largest number of systematic reviews included was human resources for health (115) followed by health financing (33), access to medicine (27), and role of the non-state sector (25). Authors based in the region produced only three systematic reviews addressing regional priorities (1.5%). Furthermore, no systematic review focused on the Eastern Mediterranean region. Primary studies from the region had limited contribution to systematic reviews; 17 systematic reviews (8.5%) included primary studies conducted in the region. Conclusions There are still gaps in the production of systematic reviews addressing policymakers’ and stakeholders’ priorities in the Eastern Mediterranean region. Efforts should be directed towards better aligning systematic review production with policy needs and priorities. Study findings can inform the agendas of researchers, research institutions, and international funding agencies of priority areas where systematic reviews are required. PMID:25139256

  19. The quest for a framework for sustainable and institutionalised priority-setting for health research in a low-resource setting: the case of Zambia.

    PubMed

    Kapiriri, Lydia; Chanda-Kapata, Pascalina

    2018-02-17

    Priority-setting for health research in low-income countries remains a major challenge. While there have been efforts to systematise and improve the processes, most of the initiatives have ended up being a one-off exercise and are yet to be institutionalised. This could, in part, be attributed to the limited capacity for the priority-setting institutions to identify and fund their own research priorities, since most of the priority-setting initiatives are driven by experts. This paper reports findings from a pilot project whose aim was to develop a systematic process to identify components of a locally desirable and feasible health research priority-setting approach and to contribute to capacity strengthening for the Zambia National Health Research Authority. Synthesis of the current literature on the approaches to health research prioritisations. The results of the synthesis were presented and discussed with a sample of Zambian researchers and decision-makers who are involved in health research priority-setting. The ultimate aim was for them to explore the different approaches available for guiding health research priority-setting and to identify an approach that would be relevant and feasible to implement and sustain within the Zambian context. Based on the evidence that was presented, the participants were unable to identify one approach that met the criteria. They identified attributes from the different approaches that they thought would be most appropriate and proposed a process that they deemed feasible within the Zambian context. While it is easier to implement prioritisation based on one approach that the initiator might be interested in, researchers interested in capacity-building for health research priority-setting organisations should expose the low-income country participants to all approaches. Researchers ought to be aware that sometimes one shoe may not fit all, as in the case of Zambia, instead of choosing one approach, the stakeholders may select desirable attributes from the different approaches and piece together an approach that would be feasible and acceptable within their context. An approach that builds on the decision-makers' understanding of their contexts and their input to its development would foster local ownership and has a greater potential for sustainability.

  20. Prioritized Contact Transport Stream

    NASA Technical Reports Server (NTRS)

    Hunt, Walter Lee, Jr. (Inventor)

    2015-01-01

    A detection process, contact recognition process, classification process, and identification process are applied to raw sensor data to produce an identified contact record set containing one or more identified contact records. A prioritization process is applied to the identified contact record set to assign a contact priority to each contact record in the identified contact record set. Data are removed from the contact records in the identified contact record set based on the contact priorities assigned to those contact records. A first contact stream is produced from the resulting contact records. The first contact stream is streamed in a contact transport stream. The contact transport stream may include and stream additional contact streams. The contact transport stream may be varied dynamically over time based on parameters such as available bandwidth, contact priority, presence/absence of contacts, system state, and configuration parameters.

  1. Optical network scaling: roles of spectral and spatial aggregation.

    PubMed

    Arık, Sercan Ö; Ho, Keang-Po; Kahn, Joseph M

    2014-12-01

    As the bit rates of routed data streams exceed the throughput of single wavelength-division multiplexing channels, spectral and spatial traffic aggregation become essential for optical network scaling. These aggregation techniques reduce network routing complexity by increasing spectral efficiency to decrease the number of fibers, and by increasing switching granularity to decrease the number of switching components. Spectral aggregation yields a modest decrease in the number of fibers but a substantial decrease in the number of switching components. Spatial aggregation yields a substantial decrease in both the number of fibers and the number of switching components. To quantify routing complexity reduction, we analyze the number of multi-cast and wavelength-selective switches required in a colorless, directionless and contentionless reconfigurable optical add-drop multiplexer architecture. Traffic aggregation has two potential drawbacks: reduced routing power and increased switching component size.

  2. The accountability for reasonableness approach to guide priority setting in health systems within limited resources--findings from action research at district level in Kenya, Tanzania, and Zambia.

    PubMed

    Byskov, Jens; Marchal, Bruno; Maluka, Stephen; Zulu, Joseph M; Bukachi, Salome A; Hurtig, Anna-Karin; Blystad, Astrid; Kamuzora, Peter; Michelo, Charles; Nyandieka, Lillian N; Ndawi, Benedict; Bloch, Paul; Olsen, Oystein E

    2014-08-20

    Priority-setting decisions are based on an important, but not sufficient set of values and thus lead to disagreement on priorities. Accountability for Reasonableness (AFR) is an ethics-based approach to a legitimate and fair priority-setting process that builds upon four conditions: relevance, publicity, appeals, and enforcement, which facilitate agreement on priority-setting decisions and gain support for their implementation. This paper focuses on the assessment of AFR within the project REsponse to ACcountable priority setting for Trust in health systems (REACT). This intervention study applied an action research methodology to assess implementation of AFR in one district in Kenya, Tanzania, and Zambia, respectively. The assessments focused on selected disease, program, and managerial areas. An implementing action research team of core health team members and supporting researchers was formed to implement, and continually assess and improve the application of the four conditions. Researchers evaluated the intervention using qualitative and quantitative data collection and analysis methods. The values underlying the AFR approach were in all three districts well-aligned with general values expressed by both service providers and community representatives. There was some variation in the interpretations and actual use of the AFR in the decision-making processes in the three districts, and its effect ranged from an increase in awareness of the importance of fairness to a broadened engagement of health team members and other stakeholders in priority setting and other decision-making processes. District stakeholders were able to take greater charge of closing the gap between nationally set planning and the local realities and demands of the served communities within the limited resources at hand. This study thus indicates that the operationalization of the four broadly defined and linked conditions is both possible and seems to be responding to an actual demand. This provides arguments for the continued application and further assessment of the potential of AFR in supporting priority-setting and other decision-making processes in health systems to achieve better agreed and more sustainable health improvements linked to a mutual democratic learning with potential wider implications.

  3. The accountability for reasonableness approach to guide priority setting in health systems within limited resources – findings from action research at district level in Kenya, Tanzania, and Zambia

    PubMed Central

    2014-01-01

    Background Priority-setting decisions are based on an important, but not sufficient set of values and thus lead to disagreement on priorities. Accountability for Reasonableness (AFR) is an ethics-based approach to a legitimate and fair priority-setting process that builds upon four conditions: relevance, publicity, appeals, and enforcement, which facilitate agreement on priority-setting decisions and gain support for their implementation. This paper focuses on the assessment of AFR within the project REsponse to ACcountable priority setting for Trust in health systems (REACT). Methods This intervention study applied an action research methodology to assess implementation of AFR in one district in Kenya, Tanzania, and Zambia, respectively. The assessments focused on selected disease, program, and managerial areas. An implementing action research team of core health team members and supporting researchers was formed to implement, and continually assess and improve the application of the four conditions. Researchers evaluated the intervention using qualitative and quantitative data collection and analysis methods. Results The values underlying the AFR approach were in all three districts well-aligned with general values expressed by both service providers and community representatives. There was some variation in the interpretations and actual use of the AFR in the decision-making processes in the three districts, and its effect ranged from an increase in awareness of the importance of fairness to a broadened engagement of health team members and other stakeholders in priority setting and other decision-making processes. Conclusions District stakeholders were able to take greater charge of closing the gap between nationally set planning and the local realities and demands of the served communities within the limited resources at hand. This study thus indicates that the operationalization of the four broadly defined and linked conditions is both possible and seems to be responding to an actual demand. This provides arguments for the continued application and further assessment of the potential of AFR in supporting priority-setting and other decision-making processes in health systems to achieve better agreed and more sustainable health improvements linked to a mutual democratic learning with potential wider implications. PMID:25142148

  4. Priority setting at the micro-, meso- and macro-levels in Canada, Norway and Uganda.

    PubMed

    Kapiriri, Lydia; Norheim, Ole Frithjof; Martin, Douglas K

    2007-06-01

    The objectives of this study were (1) to describe the process of healthcare priority setting in Ontario-Canada, Norway and Uganda at the three levels of decision-making; (2) to evaluate the description using the framework for fair priority setting, accountability for reasonableness; so as to identify lessons of good practices. We carried out case studies involving key informant interviews, with 184 health practitioners and health planners from the macro-level, meso-level and micro-level from Canada-Ontario, Norway and Uganda (selected by virtue of their varying experiences in priority setting). Interviews were audio-recorded, transcribed and analyzed using a modified thematic approach. The descriptions were evaluated against the four conditions of "accountability for reasonableness", relevance, publicity, revisions and enforcement. Areas of adherence to these conditions were identified as lessons of good practices; areas of non-adherence were identified as opportunities for improvement. (i) at the macro-level, in all three countries, cabinet makes most of the macro-level resource allocation decisions and they are influenced by politics, public pressure, and advocacy. Decisions within the ministries of health are based on objective formulae and evidence. International priorities influenced decisions in Uganda. Some priority-setting reasons are publicized through circulars, printed documents and the Internet in Canada and Norway. At the meso-level, hospital priority-setting decisions were made by the hospital managers and were based on national priorities, guidelines, and evidence. Hospital departments that handle emergencies, such as surgery, were prioritized. Some of the reasons are available on the hospital intranet or presented at meetings. Micro-level practitioners considered medical and social worth criteria. These reasons are not publicized. Many practitioners lacked knowledge of the macro- and meso-level priority-setting processes. (ii) Evaluation-relevance: medical evidence and economic criteria were thought to be relevant, but lobbying was thought to be irrelevant. Publicity: all cases lacked clear and effective mechanisms for publicity. REVISIONS: formal mechanisms, following the planning hierarchy, were considered less effective, informal political mechanisms were considered more effective. Canada and Norway had patients' relations officers to deal with patients' dissensions; however, revisions were more difficult in Uganda. Enforcement: leadership for ensuring decision-making fairness was not apparent. The different levels of priority setting in the three countries fulfilled varying conditions of accountability for reasonableness, none satisfied all the four conditions. To improve, decision makers at the three levels in all three cases should engage frontline practitioners, develop more effectively publicized reasons, and develop formal mechanisms for challenging and revising decisions.

  5. Neural Determinants of Task Performance during Feature-Based Attention in Human Cortex

    PubMed Central

    Gong, Mengyuan

    2018-01-01

    Abstract Studies of feature-based attention have associated activity in a dorsal frontoparietal network with putative attentional priority signals. Yet, how this neural activity mediates attentional selection and whether it guides behavior are fundamental questions that require investigation. We reasoned that endogenous fluctuations in the quality of attentional priority should influence task performance. Human subjects detected a speed increment while viewing clockwise (CW) or counterclockwise (CCW) motion (baseline task) or while attending to either direction amid distracters (attention task). In an fMRI experiment, direction-specific neural pattern similarity between the baseline task and the attention task revealed a higher level of similarity for correct than incorrect trials in frontoparietal regions. Using transcranial magnetic stimulation (TMS), we disrupted posterior parietal cortex (PPC) and found a selective deficit in the attention task, but not in the baseline task, demonstrating the necessity of this cortical area during feature-based attention. These results reveal that frontoparietal areas maintain attentional priority that facilitates successful behavioral selection. PMID:29497703

  6. Future Missions for Space Weather Specifications and Forecasts

    NASA Astrophysics Data System (ADS)

    Onsager, T. G.; Biesecker, D. A.; Anthes, R. A.; Maier, M. W.; Gallagher, F. W., III; St Germain, K.

    2017-12-01

    The progress of technology and the global integration of our economic and security infrastructures have introduced vulnerabilities to space weather that demand a more comprehensive ability to specify and to predict the dynamics of the space environment. This requires a comprehensive network of real-time space-based and ground-based observations with long-term continuity. In order to determine the most cost effective space architectures for NOAA's weather, space weather, and environmental missions, NOAA conducted the NOAA Satellite Observing System Architecture (NSOSA) study. This presentation will summarize the process used to document the future needs and the relative priorities for NOAA's operational space-based observations. This involves specifying the most important observations, defining the performance attributes at different levels of capability, and assigning priorities for achieving the higher capability levels. The highest priority observations recommended by the Space Platform Requirements Working Group (SPRWG) for improvement above a minimal capability level will be described. Finally, numerous possible satellite architectures have been explored to assess the costs and benefits of various architecture configurations.

  7. Intelligent bandwith compression

    NASA Astrophysics Data System (ADS)

    Tseng, D. Y.; Bullock, B. L.; Olin, K. E.; Kandt, R. K.; Olsen, J. D.

    1980-02-01

    The feasibility of a 1000:1 bandwidth compression ratio for image transmission has been demonstrated using image-analysis algorithms and a rule-based controller. Such a high compression ratio was achieved by first analyzing scene content using auto-cueing and feature-extraction algorithms, and then transmitting only the pertinent information consistent with mission requirements. A rule-based controller directs the flow of analysis and performs priority allocations on the extracted scene content. The reconstructed bandwidth-compressed image consists of an edge map of the scene background, with primary and secondary target windows embedded in the edge map. The bandwidth-compressed images are updated at a basic rate of 1 frame per second, with the high-priority target window updated at 7.5 frames per second. The scene-analysis algorithms used in this system together with the adaptive priority controller are described. Results of simulated 1000:1 band width-compressed images are presented. A video tape simulation of the Intelligent Bandwidth Compression system has been produced using a sequence of video input from the data base.

  8. 24 CFR 248.157 - Voluntary sale of housing not in excess of Federal cost limit.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... costs; (5) Receive a distribution equal to an 8 percent annual return on any actual cash investment made... by a priority purchaser seeking to make an offer during either 6-month priority purchaser marketing...-based nonprofit and the offer is submitted within the marketing period established in paragraph (c)(1...

  9. Distance Education Research Priorities for Australia: A Study of the Opinions of Distance Educators and Practitioners.

    ERIC Educational Resources Information Center

    Jegede, Olugbemiro J.

    A group of 56 randomly selected members of the International Council for Distance Education who were based in Australia were surveyed regarding their opinions on distance education research priorities for Australia. A five-page questionnaire was used to gather biographical details about respondents and opinions regarding available level of…

  10. Networking in Education: From Concept to Action--An Analytical View on the Educational Territories of Priority Intervention (TEIP) in Northern Portugal

    ERIC Educational Resources Information Center

    Silva, Marisa; da Silva, Sofia Marques; Araújo, Helena C

    2017-01-01

    This article presents an analysis of school principals' perspectives on networking concerning schools and school clusters from areas of social vulnerability (Educational Territories of Priority Intervention (TEIP)) in Northern Portugal. The meanings, purpose, benefits and difficulties of networking in education are examined, based on interviews…

  11. Memory for Object Locations: Priority Effect and Sex Differences in Associative Spatial Learning

    ERIC Educational Resources Information Center

    Cinan, Sevtap; Atalay, Deniz; Sisman, Simge; Basbug, Gokce; Dervent-Ozbek, Sevinc; Teoman, Dalga D.; Karagoz, Ayca; Karadeniz, A. Yezdan; Beykurt, Sinem; Suleyman, Hediye; Memis, H. Ozge; Yurtsever, Ozgur D.

    2007-01-01

    This paper reports two experiments conducted to examine priority effects and sex differences in object location memory. A new task of paired position-learning was designed, based on the A-B A-C paradigm, which was used in paired word learning. There were three different paired position-learning conditions: (1) positions of several different…

  12. White Paper: A Defect Prioritization Method Based on the Risk Priority Number

    DTIC Science & Technology

    2013-11-01

    adapted The Failure Modes and Effects Analysis ( FMEA ) method employs a measurement technique called Risk Priority Number (RPN) to quantify the...Up to an hour 16-60 1.5 Brief Interrupt 0-15 1 Table 1 – Time Scaling Factors In the FMEA formulation, RPN is a product of the three categories

  13. National occupational health research priorities, agenda and strategy of Japan: invited report in NORA symposium 2001, USA.

    PubMed

    Araki, Shunichi; Tachi, Masatomo

    2003-01-01

    An invited report on national occupational health research priorities, agenda and strategy of Japan was delivered in the NORA (National Occupational Research Agenda) Symposium 2001, USA. The third NORA Symposium was held by the US National Institute for Occupational Safety and Health (NIOSH) in Washington DC on June 27, 2001. The national conference in Japan entitled "Conference on Occupational Health Research Strategies in the 21st Century" was organized by the Japanese Ministry of Labour (Currently, Ministry of Health, Labour and Welfare) in the years 1998-2001, and the national occupational health research agenda and strategy for the next decade in Japan was identified. A total of 50 Conference members, i.e., representatives from various fields of occupational health in Japan, ranked 58 comprehensive research topics, yielding short-term (5-year) and long-term (6-10 year) priority research topics. Overall (10-year) priority research topics were calculated by combining the short-term and long-term priority scores. Together with the ranking by 145 extramural occupational health specialists, it was identified that work stress (i.e., one of the 58 research topics) was the first overall priority research topic for the next 10 years in Japan. Three other topics, i.e., elderly workers, women workers and maternity protection, and mental health and quality of work and life, were the second group of priority topics; and hazard and risk assessment and biological effect index were the third priority group. Based on the scores for the short-term and long-term priority research topics, all 58 research topics were classified into three key research areas with 18 key research issues (National Occupational Health Research Agenda, NOHRA). Finally, eight implementation measures of national strategy for the Japanese Government to promote occupational health research were introduced.

  14. Personal needs versus national needs: public attitudes regarding health care priorities at the personal and national levels.

    PubMed

    Kaplan, Giora; Baron-Epel, Orna

    2015-01-01

    Many stakeholders have little or no confidence in the ability of the public to express their opinions on health policy issues. The claim often arises that lay people prioritize according to their own personal experiences and may lack the broad perspective necessary to understand the needs of the population at large. In order to test this claim empirically, this study compares the public's priorities regarding personal insurance to their priorities regarding allocation of national health resources. Thus, the study should shed light on the extent to which the public's priorities at the national level are a reflection of their priorities at the personal level. A telephone survey was conducted with a representative sample of the Israeli adult population aged 18 and over (n = 1,225). The public's priorities were assessed by asking interviewees to assume that they were the Minister of Health and from this point of view allocate an additional budget among various health areas. Their priorities at the personal level were assessed by asking interviewees to choose preferred items for inclusion in their personal supplementary health insurance. Over half of the respondents (54%) expressed different personal and national priorities. In multivariable logistic analysis, "population group" was the only variable found to be statistically significant; Jews were 1.8 times more likely than Arabs to give a similar response to both questions. Income level was of borderline significance. At least half of the population was able to differentiate between their personal needs and national policy needs. We do not advocate a decision-making process based on polls or referendums. However, we believe that people should be allowed to express their priorities regarding national policy issues, and that decision-makers should consider these as one of the factors used to determine policy decisions.

  15. Where-Fi: a dynamic energy-efficient multimedia distribution framework for MANETs

    NASA Astrophysics Data System (ADS)

    Mohapatra, Shivajit; Carbunar, Bogdan; Pearce, Michael; Chaudhri, Rohit; Vasudevan, Venu

    2008-01-01

    Next generation mobile ad-hoc applications will revolve around users' need for sharing content/presence information with co-located devices. However, keeping such information fresh requires frequent meta-data exchanges, which could result in significant energy overheads. To address this issue, we propose distributed algorithms for energy efficient dissemination of presence and content usage information between nodes in mobile ad-hoc networks. First, we introduce a content dissemination protocol (called CPMP) for effectively distributing frequent small meta-data updates between co-located devices using multicast. We then develop two distributed algorithms that use the CPMP protocol to achieve "phase locked" wake up cycles for all the participating nodes in the network. The first algorithm is designed for fully-connected networks and then extended in the second to handle hidden terminals. The "phase locked" schedules are then exploited to adaptively transition the network interface to a deep sleep state for energy savings. We have implemented a prototype system (called "Where-Fi") on several Motorola Linux-based cell phone models. Our experimental results show that for all network topologies our algorithms were able to achieve "phase locking" between nodes even in the presence of hidden terminals. Moreover, we achieved battery lifetime extensions of as much as 28% for fully connected networks and about 20% for partially connected networks.

  16. Intelligent switches of integrated lightwave circuits with core telecommunication functions

    NASA Astrophysics Data System (ADS)

    Izhaky, Nahum; Duer, Reuven; Berns, Neil; Tal, Eran; Vinikman, Shirly; Schoenwald, Jeffrey S.; Shani, Yosi

    2001-05-01

    We present a brief overview of a promising switching technology based on Silica on Silicon thermo-optic integrated circuits. This is basically a 2D solid-state optical device capable of non-blocking switching operation. Except of its excellent performance (insertion loss<5dB, switching time<2ms...), the switch enables additional important build-in functionalities. It enables single-to- single channel switching and single-to-multiple channel multicasting/broadcasting. In addition, it has the capability of channel weighting and variable output power control (attenuation), for instance, to equalize signal levels and compensate for unbalanced different optical input powers, or to equalize unbalanced EDFA gain curve. We examine the market segments appropriate for the switch size and technology, followed by a discussion of the basic features of the technology. The discussion is focused on important requirements from the switch and the technology (e.g., insertion loss, power consumption, channel isolation, extinction ratio, switching time, and heat dissipation). The mechanical design is also considered. It must take into account integration of optical fiber, optical planar wafer, analog electronics and digital microprocessor controls, embedded software, and heating power dissipation. The Lynx Photon.8x8 switch is compared to competing technologies, in terms of typical market performance requirements.

  17. vMon-mobile provides wireless connection to the electronic patient record

    NASA Astrophysics Data System (ADS)

    Oliveira, Pedro P., Jr.; Rebelo, Marina; Pilon, Paulo E.; Gutierrez, Marco A.; Tachinardi, Umberto

    2002-05-01

    This work presents the development of a set of tools to help doctors to continuously monitor critical patients. Real-time monitoring signals are displayed via a Web Based Electronic Patient Record (Web-EPR) developed at the Heart Institute. Any computer on the Hospital's Intranet can access the Web-EPR that will open a browser plug-in called vMon. Recently vMon was adapted to wireless mobile devices providing the same real-time visualization of vital signals of its desktop counterpart. The monitoring network communicates with the hospital network through a gateway using HL7 messages and has the ability to export waveforms in real time using the multicast protocol through an API library. A dedicated ActiveX component was built that establishes the streaming of the biomedical signals under monitoring and displays them on an Internet Explorer 5.x browser. The mobile version - called vMon-mobile - will parse the browser window and deliver it to a PDA device connected to a local area network. The result is a virtual monitor presenting real-time data on a mobile device. All parameters and signals acquired from the moment the patient is connected to the monitors are stored for a few days. The most clinically relevant information is added to patient's EPR.

  18. Deployment of the National Transparent Optical Network around the San Francisco Bay Area

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

    McCammon, K.; Haigh, R.; Armstrong, G.

    1996-06-01

    We report on the deployment and initial operation of the National Transparent Optical Network, an experimental WDM network testbed around the San Francisco Bay Area, during the Optical Fiber Conference (OFC`96) held in San Jose, CA. The deployment aspects of the physical plant, optical and SONET layers are examined along with a discussion of broadband applications which utilized the network during the OFC`96 demonstration. The network features dense WDM technology, transparent optical routing technology using acousto- optic tunable filter based switches, and network modules with add/drop, multicast, and wavelength translation capabilities. The physical layer consisted of over 300 km ofmore » Sprint and Pacific Bell conventional single mode fiber which was amplified with I I optical amplifiers deployed in pre-amp, post-amp, and line amp configurations. An out-of-band control network provided datacom channels from remote equipment sites to the SONET network manager deployed at the San Jose Convention Center for the conference. Data transport over five wavelengths was achieved in the 1550 nm window using a variety of signal formats including analog and digital signal transmission on different wavelengths on the same fiber. The network operated throughout the week of OFC`96 and is still in operation today.« less

  19. Priority setting in practice: participants opinions on vertical and horizontal priority setting for reallocation.

    PubMed

    Waldau, Susanne; Lindholm, Lars; Wiechel, Anna Helena

    2010-08-01

    In the Västerbotten County Council in Sweden a priority setting process was undertaken to reallocate existing resources for funding of new methods and activities. Resources were created by limiting low priority services. A procedure for priority setting was constructed and fully tested by engaging the entire organisation. The procedure included priority setting within and between departments and political decision making. Participants' views and experiences were collected as a basis for future improvement of the process. Results indicate that participants appreciated the overall approach and methodology and wished to engage in their improvement. Among the improvement proposals is prolongation of the process in order to improve the knowledge base quality. The procedure for identification of new items for funding also needs to be revised. The priority setting process was considered an overall success because it fulfilled its political goals. Factors considered crucial for success are a wish among managers for an economic strategy that addresses existing internal resource allocation; process management characterized by goal orientation and clear leadership; an elaborate communications strategy integrated early in the process and its management; political unity in support of the procedure, and a strong political commitment throughout the process. Generalizability has already been demonstrated by several health care organisations that performed processes founded on this working model. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.

  20. The Development of a Veterans Health Administration Emergency Management Research Agenda

    PubMed Central

    Dobalian, Aram; Claver, Maria; Riopelle, Deborah; Wyte-Lake, Tamar; Canelo, Ismelda

    2017-01-01

    Introduction: The Veterans Health Administration (VHA), the largest integrated healthcare delivery system in the United States, is charged with ensuring timely access to high-quality care for veterans during disasters, and supporting national, state, local, and tribal emergency management and homeland security efforts. In 2008, the VHA Office of Public Health (OPH) sponsored the first VHA Emergency Management Research Agenda-setting conference to develop research priorities that address the needs of veterans and to position VHA as a national leader in emergency management by having VHA serve as a “laboratory” for the development of evidence-based emergency management practices. Methods: We focused on four steps: #1: Appraising the emergency management research portfolio of VHA-based researchers; #2: Obtaining systematic information on VHA’s role in emergency management and the healthcare needs of veterans during disasters; #3: Based upon gaps between the current research portfolio and the existing evidence base, identifying strategic priorities using a research agenda-setting conference; and #4: Laying the groundwork to foster the conduct of emergency management research within VHA. Results: Identified research priorities included how to prevent and treat behavioral health problems related to a disaster, the efficacy of training programs, crisis communication strategies, workforce resilience, and evacuating veterans from health care facilities. Conclusion: VHA is uniquely situated to answer research questions that cannot be readily addressed in other settings. VHA should partner with other governmental and private entities to build on existing work and establish shared research priorities. PMID:28439447

  1. Cryptographic framework for document-objects resulting from multiparty collaborative transactions.

    PubMed

    Goh, A

    2000-01-01

    Multiparty transactional frameworks--i.e. Electronic Data Interchange (EDI) or Health Level (HL) 7--often result in composite documents which can be accurately modelled using hyperlinked document-objects. The structural complexity arising from multiauthor involvement and transaction-specific sequencing would be poorly handled by conventional digital signature schemes based on a single evaluation of a one-way hash function and asymmetric cryptography. In this paper we outline the generation of structure-specific authentication hash-trees for the the authentication of transactional document-objects, followed by asymmetric signature generation on the hash-tree value. Server-side multi-client signature verification would probably constitute the single most compute-intensive task, hence the motivation for our usage of the Rabin signature protocol which results in significantly reduced verification workloads compared to the more commonly applied Rivest-Shamir-Adleman (RSA) protocol. Data privacy is handled via symmetric encryption of message traffic using session-specific keys obtained through key-negotiation mechanisms based on discrete-logarithm cryptography. Individual client-to-server channels can be secured using a double key-pair variation of Diffie-Hellman (DH) key negotiation, usage of which also enables bidirectional node authentication. The reciprocal server-to-client multicast channel is secured through Burmester-Desmedt (BD) key-negotiation which enjoys significant advantages over the usual multiparty extensions to the DH protocol. The implementation of hash-tree signatures and bi/multidirectional key negotiation results in a comprehensive cryptographic framework for multiparty document-objects satisfying both authentication and data privacy requirements.

  2. Neuroprosthesis consumers' forum: consumer priorities for research directions.

    PubMed

    Kilgore, K L; Scherer, M; Bobblitt, R; Dettloff, J; Dombrowski, D M; Godbold, N; Jatich, J W; Morris, R; Penko, J S; Schremp, E S; Cash, L A

    2001-01-01

    The purpose of this forum was to discuss with consumers having spinal cord injury what their research priorities would be for the field of functional electrical stimulation (FES) and to explore the impact of technology in the lives of people with disabilities. Both FES users and nonusers were included on the panel. The format for the discussion was primarily question and answer, with each participant giving his or her personal response to the moderator's question. Consumer research priorities depended on the individual and his or her personal priorities, preferences, background, history, and level of injury. Common themes that emerged were independence, ease of movement, ease of control, and spontaneity. From the consumers' perspective, the focus of research to restore function ought to be based on the needs and desires of the consumer, not just on the scientifically intriguing aspects of a particular technology.

  3. Next Generation Integrated Environment for Collaborative Work Across Internets

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

    Harvey B. Newman

    2009-02-24

    We are now well-advanced in our development, prototyping and deployment of a high performance next generation Integrated Environment for Collaborative Work. The system, aimed at using the capability of ESnet and Internet2 for rapid data exchange, is based on the Virtual Room Videoconferencing System (VRVS) developed by Caltech. The VRVS system has been chosen by the Internet2 Digital Video (I2-DV) Initiative as a preferred foundation for the development of advanced video, audio and multimedia collaborative applications by the Internet2 community. Today, the system supports high-end, broadcast-quality interactivity, while enabling a wide variety of clients (Mbone, H.323) to participate in themore » same conference by running different standard protocols in different contexts with different bandwidth connection limitations, has a fully Web-integrated user interface, developers and administrative APIs, a widely scalable video network topology based on both multicast domains and unicast tunnels, and demonstrated multiplatform support. This has led to its rapidly expanding production use for national and international scientific collaborations in more than 60 countries. We are also in the process of creating a 'testbed video network' and developing the necessary middleware to support a set of new and essential requirements for rapid data exchange, and a high level of interactivity in large-scale scientific collaborations. These include a set of tunable, scalable differentiated network services adapted to each of the data streams associated with a large number of collaborative sessions, policy-based and network state-based resource scheduling, authentication, and optional encryption to maintain confidentiality of inter-personal communications. High performance testbed video networks will be established in ESnet and Internet2 to test and tune the implementation, using a few target application-sets.« less

  4. Identifying environmental health priorities in underserved populations: a study of rural versus urban communities

    PubMed Central

    Bernhard, M.C.; Evans, M.B.; Kent, S.T.; Johnson, E.; Threadgill, S.L.; Tyson, S.; Becker, S.M.; Gohlke, J.M.

    2013-01-01

    Objectives Understanding and effectively addressing persistent health disparities in minority communities requires a clear picture of members’ concerns and priorities. This study was intended to engage residents in urban and rural communities in order to identify environmental health priorities. Specific emphasis was placed on how the communities defined the term environment, their perceptions of environmental exposures as affecting their health, specific priorities in their communities, and differences in urban versus rural populations. Study design A community-engaged approach was used to develop and implement focus groups and compare environmental health priorities in urban versus rural communities. Methods A total of eight focus groups were conducted: four in rural and four in urban communities. Topics included defining the term environment, how the environment may affect health, and environmental priorities within their communities, using both open discussion and a predefined list. Data were analysed both qualitatively and quantitatively to identify patterns and trends. Results There were important areas of overlap in priorities between urban and rural communities; both emphasized the importance of the social environment and shared a concern over air pollution from industrial sources. In contrast, for urban focus groups, abandoned houses and their social and physical sequelae were a high priority while concerns about adequate sewer and water services and road maintenance were high priorities in rural communities. Conclusions This study was able to identify environmental health priorities in urban versus rural minority communities. In contrast to some previous risk perception research, the results of this study suggest prioritization of tangible, known risks in everyday life instead of rare, disaster-related events, even in communities that have recently experienced devastating damage from tornadoes. The findings can help inform future efforts to study, understand and effectively address environmental issues, and are particularly relevant to developing effective community-based strategies in vulnerable populations. PMID:24239281

  5. What should dental services for people with disabilities be like? Results of an Irish Delphi panel survey.

    PubMed

    Mac Giolla Phadraig, Caoimhin; Nunn, June; Dougall, Alison; O'Neill, Eunan; McLoughlin, Jacinta; Guerin, Suzanne

    2014-01-01

    This study aimed to generate prioritised goals for oral health services for people with disabilities as a first step in meeting the need for evidence based oral health services for people with disabilities in Ireland. The study used a three round modified e-Delphi method, involving dental service professionals and people with disabilities or their representatives, in Ireland. Three rounds were completed online using SurveyMonkey. Round 1 asked: "List what you think dental services for people with disabilities in Ireland should be like." Items for subsequent rounds were generated from responses to Round 1. Round 2 and Round 3 used 5 point Likert scales to rank these items by priority: from No Priority (1) to Top Priority (5). Consensus was achieved on each item where at least 80% of respondents considered an item either High or Top Priority. A consensus meeting concluded the process. Sixty-one panelists started and 48 completed the survey. The Delphi panel agreed on level of priority for 69 items and generated 16 consensus statements. These statements covered a range of topics such as access to care, availability of information and training, quality of care, dental treatment and cost. A recurrent theme relating to the appropriateness of care to individual need arose across topics suggesting a need to match service delivery according to the individual's needs, wants and expectations rather than the disability type/diagnosis based service which predominates today. This process produced a list of prioritised goals for dental services for people with disabilities. This creates a foundation for building evidence-based service models for people with disabilities in Ireland.

  6. Earthquake Early Warning: Real-time Testing of an On-site Method Using Waveform Data from the Southern California Seismic Network

    NASA Astrophysics Data System (ADS)

    Solanki, K.; Hauksson, E.; Kanamori, H.; Wu, Y.; Heaton, T.; Boese, M.

    2007-12-01

    We have implemented an on-site early warning algorithm using the infrastructure of the Caltech/USGS Southern California Seismic Network (SCSN). We are evaluating the real-time performance of the software system and the algorithm for rapid assessment of earthquakes. In addition, we are interested in understanding what parts of the SCSN need to be improved to make early warning practical. Our EEW processing system is composed of many independent programs that process waveforms in real-time. The codes were generated by using a software framework. The Pd (maximum displacement amplitude of P wave during the first 3sec) and Tau-c (a period parameter during the first 3 sec) values determined during the EEW processing are being forwarded to the California Integrated Seismic Network (CISN) web page for independent evaluation of the results. The on-site algorithm measures the amplitude of the P-wave (Pd) and the frequency content of the P-wave during the first three seconds (Tau-c). The Pd and the Tau-c values make it possible to discriminate between a variety of events such as large distant events, nearby small events, and potentially damaging nearby events. The Pd can be used to infer the expected maximum ground shaking. The method relies on data from a single station although it will become more reliable if readings from several stations are associated. To eliminate false triggers from stations with high background noise level, we have created per station Pd threshold configuration for the Pd/Tau-c algorithm. To determine appropriate values for the Pd threshold we calculate Pd thresholds for stations based on the information from the EEW logs. We have operated our EEW test system for about a year and recorded numerous earthquakes in the magnitude range from M3 to M5. Two recent examples are a M4.5 earthquake near Chatsworth and a M4.7 earthquake near Elsinore. In both cases, the Pd and Tau-c parameters were determined successfully within 10 to 20 sec of the arrival of the P-wave at the station. The Tau-c values predicted the magnitude within 0.1 and the predicted average peak-ground-motion was 0.7 cm/s and 0.6 cm/s. The delays in the system are caused mostly by the packetizing delay because our software system is based on processing miniseed packets. Most recently we have begun reducing the data latency using new qmaserv2 software for the Q330 Quanterra datalogger. We implemented qmaserv2 based multicast receiver software to receive the native 1 sec packets from the dataloggers. The receiver reads multicast packets from the network and writes them into shared memory area. This new software will fully take advantage of the capabilities of the Q330 datalogger and significantly reduce data latency for EEW system. We have also implemented a new EEW sub-system that compliments the currently running EEW system by associating Pd and Tau-c values from multiple stations. So far, we have implemented a new trigger generation algorithm for real-time processing for the sub-system, and are able to routinely locate events and determine magnitudes using the Pd and Tau-c values.

  7. Using evaluation theory in priority setting and resource allocation.

    PubMed

    Smith, Neale; Mitton, Craig; Cornelissen, Evelyn; Gibson, Jennifer; Peacock, Stuart

    2012-01-01

    Public sector interest in methods for priority setting and program or policy evaluation has grown considerably over the last several decades, given increased expectations for accountable and efficient use of resources and emphasis on evidence-based decision making as a component of good management practice. While there has been some occasional effort to conduct evaluation of priority setting projects, the literatures around priority setting and evaluation have largely evolved separately. In this paper, the aim is to bring them together. The contention is that evaluation theory is a means by which evaluators reflect upon what it is they are doing when they do evaluation work. Theories help to organize thinking, sort out relevant from irrelevant information, provide transparent grounds for particular implementation choices, and can help resolve problematic issues which may arise in the conduct of an evaluation project. A detailed review of three major branches of evaluation theory--methods, utilization, and valuing--identifies how such theories can guide the development of efforts to evaluate priority setting and resource allocation initiatives. Evaluation theories differ in terms of their guiding question, anticipated setting or context, evaluation foci, perspective from which benefits are calculated, and typical methods endorsed. Choosing a particular theoretical approach will structure the way in which any priority setting process is evaluated. The paper suggests that explicitly considering evaluation theory makes key aspects of the evaluation process more visible to all stakeholders, and can assist in the design of effective evaluation of priority setting processes; this should iteratively serve to improve the understanding of priority setting practices themselves.

  8. Research priorities in mental health occupational therapy: A study of clinician perspectives.

    PubMed

    Hitch, Danielle; Lhuede, Kate

    2015-10-01

    The evidence to support mental health occupational therapy has proliferated in the early years of this century, but this growth has tended to be organic rather than targeted. Previous efforts to identify research priorities in this area of practice are either out dated, or encompass discrete areas of practice. The aim of this study was to identify priority areas for research in mental health occupational therapy from clinician's perspectives. A Policy Delphi method was used to enable occupational therapists to define and differentiate their perspectives on research priorities. Forty-two occupational therapists took part in the first two rounds of this method, with 69% (n = 29) going on to complete the third and final round of data collection. A Likert scale was used to rate the importance of each priority, and descriptive quantitative analysis undertaken to identify those most consistently identified as being highly important. Four research priorities were identified as being highly important in this study: (i) working in an occupationally focussed way; (ii) consumer experience of therapy groups; (iii) identifying factors which increase consumer engagement in occupation; and (iv) engaging patients on the inpatient unit in meaningful and positive occupation. Two of the priority areas are already the subject of substantial evidence bases, but there has been far less research into consumer experiences of groups and occupational engagement in acute settings. Collaboration between research teams and greater consumer inclusion are recommended for the future. This study provides an updated indication of research priorities for mental health occupational therapy in Australia. © 2015 Occupational Therapy Australia.

  9. What are the dietary treatment research priorities for inflammatory bowel disease? A short report based on a priority setting partnership with the James Lind Alliance.

    PubMed

    Lomer, M C; Hart, A L; Verjee, A; Daly, A; Solomon, J; Mclaughlin, J

    2017-12-01

    Treatment of inflammatory bowel disease (IBD) involves a multidisciplinary approach comprising medical management and sometimes surgery. Although diet is central to IBD management, the optimal diet for patients with IBD is uncertain. A UK collaborative partnership within the James Lind Alliance was set up between patients, clinicians and other stakeholders to develop research priorities in IBD. The aim of this short report is to provide a comprehensive summary of the research priority findings relating to diet in the treatment of IBD. The James Lind Alliance Priority Setting Partnership process was used to develop research priorities in IBD. In brief, patients, clinicians and other stakeholders were invited to provide up to five treatment uncertainties in IBD. These uncertainties were collated, revised and ranked, leading to a final top 10 research questions in IBD. A total of 1671 uncertainties from 531 participants were collected and refined to exclude duplicates leaving 1253 uncertainties. Of these, 348 were categorised as diet-related and grouped according to topic. There were 206 uncertainties related to how diet can be used to treat IBD or alleviate symptoms. Seventy-two percent of diet-related questions came from patients. One broadly diet-related and two diet-specific treatment uncertainties were included in the top 10 research priorities for IBD. Dietary treatment options in the management of IBD are important research priorities. Almost three-quarters of diet related questions came from patients, who were particularly interested in how diet can impact disease activity and symptom control. © 2017 The British Dietetic Association Ltd.

  10. Altering spatial priority maps via reward-based learning.

    PubMed

    Chelazzi, Leonardo; Eštočinová, Jana; Calletti, Riccardo; Lo Gerfo, Emanuele; Sani, Ilaria; Della Libera, Chiara; Santandrea, Elisa

    2014-06-18

    Spatial priority maps are real-time representations of the behavioral salience of locations in the visual field, resulting from the combined influence of stimulus driven activity and top-down signals related to the current goals of the individual. They arbitrate which of a number of (potential) targets in the visual scene will win the competition for attentional resources. As a result, deployment of visual attention to a specific spatial location is determined by the current peak of activation (corresponding to the highest behavioral salience) across the map. Here we report a behavioral study performed on healthy human volunteers, where we demonstrate that spatial priority maps can be shaped via reward-based learning, reflecting long-lasting alterations (biases) in the behavioral salience of specific spatial locations. These biases exert an especially strong influence on performance under conditions where multiple potential targets compete for selection, conferring competitive advantage to targets presented in spatial locations associated with greater reward during learning relative to targets presented in locations associated with lesser reward. Such acquired biases of spatial attention are persistent, are nonstrategic in nature, and generalize across stimuli and task contexts. These results suggest that reward-based attentional learning can induce plastic changes in spatial priority maps, endowing these representations with the "intelligent" capacity to learn from experience. Copyright © 2014 the authors 0270-6474/14/348594-11$15.00/0.

  11. Prioritizing human pharmaceuticals for ecological risks in the freshwater environment of Korea.

    PubMed

    Ji, Kyunghee; Han, Eun Jeong; Back, Sunhyoung; Park, Jeongim; Ryu, Jisung; Choi, Kyungho

    2016-04-01

    Pharmaceutical residues are potential threats to aquatic ecosystems. Because more than 3000 active pharmaceutical ingredients (APIs) are in use, identifying high-priority pharmaceuticals is important for developing appropriate management options. Priority pharmaceuticals may vary by geographical region, because their occurrence levels can be influenced by demographic, societal, and regional characteristics. In the present study, the authors prioritized human pharmaceuticals of potential ecological risk in the Korean water environment, based on amount of use, biological activity, and regional hydrologic characteristics. For this purpose, the authors estimated the amounts of annual production of 695 human APIs in Korea. Then derived predicted environmental concentrations, using 2 approaches, to develop an initial candidate list of target pharmaceuticals. Major antineoplastic drugs and hormones were added in the initial candidate list regardless of their production amount because of their high biological activity potential. The predicted no effect concentrations were derived for those pharmaceuticals based on ecotoxicity information available in the literature or by model prediction. Priority lists of human pharmaceuticals were developed based on ecological risks and availability of relevant information. Those priority APIs identified include acetaminophen, clarithromycin, ciprofloxacin, ofloxacin, metformin, and norethisterone. Many of these pharmaceuticals have been neither adequately monitored nor assessed for risks in Korea. Further efforts are needed to improve these lists and to develop management decisions for these compounds in Korean water. © 2015 SETAC.

  12. Exploring the Sexual Health Priorities and Needs of Immigrant Latinas in the Southeastern United States: A Community-Based Participatory Research Approach

    ERIC Educational Resources Information Center

    Cashman, Rebecca; Eng, Eugenia; Siman, Florence; Rhodes, Scott D.

    2011-01-01

    Latinas living in the United States are disproportionately affected by HIV/AIDS and sexually transmitted infections. However, few effective interventions currently exist that are designed to meet the priorities and needs of recently arrived and less acculturated immigrant Latinas who are settling in the southeastern United States. To identify…

  13. Setting Priorities for Graduate Medical Education,

    DTIC Science & Technology

    1996-02-01

    assist the work of these staffs. 14. SUBJECT TERMS Attrition, data bases, education , mathematical models, medical personnel, military medicine, naval...CRM 95-209 / February 1996 Setting Priorities for Graduate Medical Education Neil B. Carey • Marjorie D. Curia • Oliver A. Smith 19960718 027...the tirae for reviewing instructions, searching existing data sources gathering and maintaining the data needed, and reviewing the collection of

  14. Tree hazard control on recreation sites...estimating local budgets

    Treesearch

    Lee A. Paine

    1967-01-01

    Tree hazard control efforts on recreation sites are subject to budget and administrative restrictions. To make the most effective use of available control funds, priorities should be assigned to various classes of tree defects and a budget set up. With the method provided, local priorities are based on cost effectiveness. Some guide lines and a worksheet for planning a...

  15. 34 CFR 403.111 - How must funds be used under the Secondary School Vocational Education Program and the...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... individuals who are members of special populations. Examples: Methods by which an eligible recipient may give... special populations include, but are not limited to, the following: Example 1: Method to give priority to...: Method to give priority to a limited number of program areas. Based on data from the preceding fiscal...

  16. 34 CFR 403.111 - How must funds be used under the Secondary School Vocational Education Program and the...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... individuals who are members of special populations. Examples: Methods by which an eligible recipient may give... special populations include, but are not limited to, the following: Example 1: Method to give priority to...: Method to give priority to a limited number of program areas. Based on data from the preceding fiscal...

  17. 34 CFR 403.111 - How must funds be used under the Secondary School Vocational Education Program and the...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... individuals who are members of special populations. Examples: Methods by which an eligible recipient may give... special populations include, but are not limited to, the following: Example 1: Method to give priority to...: Method to give priority to a limited number of program areas. Based on data from the preceding fiscal...

  18. Governance factors in the identification of global conservation priorities for mammals

    PubMed Central

    Eklund, Johanna; Arponen, Anni; Visconti, Piero; Cabeza, Mar

    2011-01-01

    Global conservation priorities have often been identified based on the combination of species richness and threat information. With the development of the field of systematic conservation planning, more attention has been given to conservation costs. This leads to prioritizing developing countries, where costs are generally low and biodiversity is high. But many of these countries have poor governance, which may result in ineffective conservation or in larger costs than initially expected. We explore how the consideration of governance affects the selection of global conservation priorities for the world's mammals in a complementarity-based conservation prioritization. We use data on Control of Corruption (Worldwide Governance Indicators project) as an indicator of governance effectiveness, and gross domestic product per capita as an indicator of cost. We show that, while core areas with high levels of endemism are always selected as important regardless of governance and cost values, there are clear regional differences in selected sites when biodiversity, cost or governance are taken into account separately. Overall, the analysis supports the concentration of conservation efforts in most of the regions generally considered of high priority, but stresses the need for different conservation approaches in different continents owing to spatial patterns of governance and economic development. PMID:21844045

  19. Governance factors in the identification of global conservation priorities for mammals.

    PubMed

    Eklund, Johanna; Arponen, Anni; Visconti, Piero; Cabeza, Mar

    2011-09-27

    Global conservation priorities have often been identified based on the combination of species richness and threat information. With the development of the field of systematic conservation planning, more attention has been given to conservation costs. This leads to prioritizing developing countries, where costs are generally low and biodiversity is high. But many of these countries have poor governance, which may result in ineffective conservation or in larger costs than initially expected. We explore how the consideration of governance affects the selection of global conservation priorities for the world's mammals in a complementarity-based conservation prioritization. We use data on Control of Corruption (Worldwide Governance Indicators project) as an indicator of governance effectiveness, and gross domestic product per capita as an indicator of cost. We show that, while core areas with high levels of endemism are always selected as important regardless of governance and cost values, there are clear regional differences in selected sites when biodiversity, cost or governance are taken into account separately. Overall, the analysis supports the concentration of conservation efforts in most of the regions generally considered of high priority, but stresses the need for different conservation approaches in different continents owing to spatial patterns of governance and economic development.

  20. Oxidative Priority, Meal Frequency, and the Energy Economy of Food and Activity: Implications for Longevity, Obesity, and Cardiometabolic Disease

    PubMed Central

    Cronise, Raymond J.; Sinclair, David A.

    2017-01-01

    Abstract In most modern societies, the relationship that many individuals have with food has fundamentally changed from previous generations. People have shifted away from viewing food as primarily sustenance, and rather now seek out foods based on pure palatability or specific nutrition. However, it is far from clear what optimal nutrition is for the general population or specific individuals. We previously described the Food Triangle as a way to organize food based on an increasing energy density paradigm, and now expand on this model to predict the impact of oxidative priority and both nutrient and fiber density in relation to caloric load. When combined with meal frequency, integrated energy expenditure, macronutrient oxidative priority, and fuel partitioning expressed by the respiratory quotient, our model also offers a novel explanation for chronic overnutrition and the cause of excess body fat accumulation. Herein, we not only review how metabolism is a dynamic process subject to many regulators that mediate the fate of ingested calories but also discuss how the Food Triangle predicts the oxidative priority of ingested foods and provides a conceptual paradigm for healthy eating supported by health and longevity research. PMID:27869525

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