Science.gov

Sample records for cooperative base stations

  1. Cell Edge Capacity Improvement by Using Adaptive Base Station Cooperation in Cellular Networks with Fractional Frequency Reuse

    NASA Astrophysics Data System (ADS)

    Xu, Liang; Yamamoto, Koji; Murata, Hidekazu; Yoshida, Susumu

    The present paper focuses on the application of the base station cooperation (BSC) technique in fractional frequency reuse (FFR) networks. Fractional frequency reuse is considered to be a promising scheme for avoiding the inter-cell interference problem in OFDMA cellular systems, such as WiMAX, in which the edge mobile stations (MSs) of adjacent cells use different subchannels for separate transmission. However, the problem of FFR is that the cell edge spectral efficiency (SE) is much lower than that of the cell center. The BSC technique, in which adjacent BSs perform cooperative transmission for one cell edge MS with the same channel, may improve the cell edge SE. However, since more BSs transmit signals for one cell edge MS, the use of BSC can also increase the inter-cell interference, which might degrade the network performance. In this paper, with a focus on this tradeoff, we propose an adaptive BSC scheme in which BSC is only performed for the cell edge MSs that can achieve a significant capacity increase with only a slight increase in inter-cell interference. Moreover, a channel reallocation scheme is proposed in order to further improve the performance of the adaptive BSC scheme. The simulation results reveal that, compared to the conventional FFR scheme, the proposed schemes are effective for improving the performance of FFR networks.

  2. PBS's Station Program Cooperative: A Political Experiment.

    ERIC Educational Resources Information Center

    Avery, Robert K.

    The Public Broadcasting Service (PBS) has developed a new means of financing a portion of PBS' national programing--the "Station Program Cooperative" (SPC). Established in April 1974, the SPC is the product of a multifaceted attack on three critical and interrelated problems: (1) an increasing scarcity of funds for national programing;…

  3. Space Station - Opportunity for international cooperation and utilization

    NASA Technical Reports Server (NTRS)

    Pedersen, K. S.

    1984-01-01

    In connection with his announcement regarding the development of a permanently manned Space Station, President Reagan invited the United States' friends and allies to join in the Space Station program. The President's invitation was preceded by more than two years of interaction between NASA and some of its potential partners in Space Station planning activities. Attention is given to international participation in Space Station planning, international cooperation on the Space Station, the guidelines for international cooperation, and the key challenges. Questions regarding quid pro quos are considered along with aspects of technology transfer, commercial use, problems of management, and the next steps concerning the Space Station program.

  4. Space Station - Opportunity for international cooperation and utilization

    NASA Technical Reports Server (NTRS)

    Pedersen, K. S.

    1984-01-01

    In connection with his announcement regarding the development of a permanently manned Space Station, President Reagan invited the United States' friends and allies to join in the Space Station program. The President's invitation was preceded by more than two years of interaction between NASA and some of its potential partners in Space Station planning activities. Attention is given to international participation in Space Station planning, international cooperation on the Space Station, the guidelines for international cooperation, and the key challenges. Questions regarding quid pro quos are considered along with aspects of technology transfer, commercial use, problems of management, and the next steps concerning the Space Station program.

  5. International cooperation in the Space Station programme - Assessing the experience to date

    NASA Technical Reports Server (NTRS)

    Logsdon, John M.

    1991-01-01

    The origins and framework for cooperation in the Space Station program are outlined. Particular attention is paid to issues and commitments between the countries and to the political context of the Station partnership. A number of conclusions concerning international cooperation in space are drawn based on the Space Station experience. Among these conclusions is the assertion that an international partnership requires realistic assesments, mutual trust, and strong commitments in order to work.

  6. International cooperation in the Space Station programme - Assessing the experience to date

    NASA Technical Reports Server (NTRS)

    Logsdon, John M.

    1991-01-01

    The origins and framework for cooperation in the Space Station program are outlined. Particular attention is paid to issues and commitments between the countries and to the political context of the Station partnership. A number of conclusions concerning international cooperation in space are drawn based on the Space Station experience. Among these conclusions is the assertion that an international partnership requires realistic assesments, mutual trust, and strong commitments in order to work.

  7. 75 FR 33238 - Basin Electric Power Cooperative: Deer Creek Station

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-11

    ...; ] DEPARTMENT OF AGRICULTURE Rural Utilities Service Basin Electric Power Cooperative: Deer Creek Station AGENCY... Basin Electric Power Cooperative's (Basin Electric) application for a RUS loan and a Western... Office, 314 6th Avenue, Brookings, SD. SUPPLEMENTARY INFORMATION: Basin Electric's proposed Project is to...

  8. 75 FR 8895 - Basin Electric Power Cooperative: Deer Creek Station

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-26

    ...; ] DEPARTMENT OF AGRICULTURE Rural Utilities Service Basin Electric Power Cooperative: Deer Creek Station AGENCY... potential environmental impacts of and alternatives to Basin Electric Power Cooperative's (Basin Electric...: (202) 690-0649, or e-mail: lauren.mcgee @wdc.usda.gov. SUPPLEMENTARY INFORMATION: Basin Electric's...

  9. 75 FR 43915 - Basin Electric Power Cooperative: Deer Creek Station

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-27

    ... Rural Utilities Service Basin Electric Power Cooperative: Deer Creek Station AGENCY: Rural Utilities... environmental impacts of and alternatives to Basin Electric Power Cooperative's (Basin Electric) application for...://www.usda.gov/rus/water/ees/eis.htm . SUPPLEMENTARY INFORMATION: Basin Electric's proposed Project is...

  10. International cooperation in the Space Station

    NASA Technical Reports Server (NTRS)

    Raney, William P.

    1987-01-01

    The principles and policies governing participation in the International Space Station are examined from a NASA perspective. The history of the program is reviewed; the most important aspects of the partnership concept (functional allocation, shared access, and interface commonality) are considered in detail; and the ongoing outfitting studies are briefly characterized. Major issues remaining to be negotiated include (1) the overall management structure; (2) the division of responsibilities for system design, integration, operation, and utilization; and (3) the sharing of operating costs.

  11. International cooperation in the Space Station

    NASA Technical Reports Server (NTRS)

    Raney, William P.

    1987-01-01

    The principles and policies governing participation in the International Space Station are examined from a NASA perspective. The history of the program is reviewed; the most important aspects of the partnership concept (functional allocation, shared access, and interface commonality) are considered in detail; and the ongoing outfitting studies are briefly characterized. Major issues remaining to be negotiated include (1) the overall management structure; (2) the division of responsibilities for system design, integration, operation, and utilization; and (3) the sharing of operating costs.

  12. Space Station - A model for future cooperation in space

    NASA Technical Reports Server (NTRS)

    Raney, W. P.

    1986-01-01

    Advances in the ability to operate in, and thus to exploit, space have come more rapidly than almost anything else that has been done. From the beginning, nations have engaged in both cooperation and competition, from the stage of adventurous exploration to the current routine commercial activity. The Space Station program serves as a focus for the free world to move forward together, sharing both risks and benefits during the initial, formative period of an entirely new level of capability.

  13. 75 FR 8153 - Nebraska Public Power District; Cooper Nuclear Station Environmental Assessment and Finding of No...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-23

    ... COMMISSION Nebraska Public Power District; Cooper Nuclear Station Environmental Assessment and Finding of No... District (NPPD, the licensee), for operation of the Cooper Nuclear Station (CNS), located in Nemaha County... Statement for the Cooper Nuclear Station dated February 1973. Agencies and Persons Consulted In...

  14. International Cooperation of Payload Operations on the International Space Station

    NASA Technical Reports Server (NTRS)

    Melton, Tina; Onken, Jay

    2003-01-01

    One of the primary goals of the International Space Station (ISS) is to provide an orbiting laboratory to be used to conduct scientific research and commercial products utilizing the unique environment of space. The ISS Program has united multiple nations into a coalition with the objective of developing and outfitting this orbiting laboratory and sharing in the utilization of the resources available. The primary objectives of the real- time integration of ISS payload operations are to ensure safe operations of payloads, to avoid mutual interference between payloads and onboard systems, to monitor the use of integrated station resources and to increase the total effectiveness of ISS. The ISS organizational architecture has provided for the distribution of operations planning and execution functions to the organizations with expertise to perform each function. Each IPP is responsible for the integration and operations of their payloads within their resource allocations and the safety requirements defined by the joint program. Another area of international cooperation is the sharing in the development and on- orbit utilization of unique payload facilities. An example of this cooperation is the Microgravity Science Glovebox. The hardware was developed by ESA and provided to NASA as part of a barter arrangement.

  15. International Cooperation of Payload Operations on the International Space Station

    NASA Technical Reports Server (NTRS)

    Melton, Tina; Onken, Jay

    2003-01-01

    One of the primary goals of the International Space Station (ISS) is to provide an orbiting laboratory to be used to conduct scientific research and commercial products utilizing the unique environment of space. The ISS Program has united multiple nations into a coalition with the objective of developing and outfitting this orbiting laboratory and sharing in the utilization of the resources available. The primary objectives of the real- time integration of ISS payload operations are to ensure safe operations of payloads, to avoid mutual interference between payloads and onboard systems, to monitor the use of integrated station resources and to increase the total effectiveness of ISS. The ISS organizational architecture has provided for the distribution of operations planning and execution functions to the organizations with expertise to perform each function. Each IPP is responsible for the integration and operations of their payloads within their resource allocations and the safety requirements defined by the joint program. Another area of international cooperation is the sharing in the development and on- orbit utilization of unique payload facilities. An example of this cooperation is the Microgravity Science Glovebox. The hardware was developed by ESA and provided to NASA as part of a barter arrangement.

  16. American experiences and perspectives - International cooperation on a permanently manned Space Station

    NASA Technical Reports Server (NTRS)

    Pedersen, K. S.

    1985-01-01

    In the late 1960s, NASA contemplated the establishment of a permanently manned Space Station along with the development of the Space Shuttle. After a temporary postponement of the Space Station project, it was finally decided to develop a Space Station and to have it operating by the early 1990s. This station is to serve in a variety of functions which are important for further advances with respect to the utilization of space. The Space Station could even serve as a staging base for trips to the moon and visits to Mars. An international approach is to be taken regarding the development and utilization of the Space Station, giving attention to a cooperation of the U.S. with Canada, Europe, and Japan. The implementation of such a cooperation requires that a number of problems are solved. Basic approaches suitable for achieving such a solution are discussed, taking into account the development of operational schemes which provide for efficient management, while permitting the exercise of diverse 'ownership' rights.

  17. American experiences and perspectives - International cooperation on a permanently manned Space Station

    NASA Technical Reports Server (NTRS)

    Pedersen, K. S.

    1985-01-01

    In the late 1960s, NASA contemplated the establishment of a permanently manned Space Station along with the development of the Space Shuttle. After a temporary postponement of the Space Station project, it was finally decided to develop a Space Station and to have it operating by the early 1990s. This station is to serve in a variety of functions which are important for further advances with respect to the utilization of space. The Space Station could even serve as a staging base for trips to the moon and visits to Mars. An international approach is to be taken regarding the development and utilization of the Space Station, giving attention to a cooperation of the U.S. with Canada, Europe, and Japan. The implementation of such a cooperation requires that a number of problems are solved. Basic approaches suitable for achieving such a solution are discussed, taking into account the development of operational schemes which provide for efficient management, while permitting the exercise of diverse 'ownership' rights.

  18. Cooperative processing data bases

    NASA Technical Reports Server (NTRS)

    Hasta, Juzar

    1991-01-01

    Cooperative processing for the 1990's using client-server technology is addressed. The main theme is concepts of downsizing from mainframes and minicomputers to workstations on a local area network (LAN). This document is presented in view graph form.

  19. Mechanisms for similarity based cooperation

    NASA Astrophysics Data System (ADS)

    Traulsen, A.

    2008-06-01

    Cooperation based on similarity has been discussed since Richard Dawkins introduced the term “green beard” effect. In these models, individuals cooperate based on an aribtrary signal (or tag) such as the famous green beard. Here, two different models for such tag based cooperation are analysed. As neutral drift is important in both models, a finite population framework is applied. The first model, which we term “cooperative tags” considers a situation in which groups of cooperators are formed by some joint signal. Defectors adopting the signal and exploiting the group can lead to a breakdown of cooperation. In this case, conditions are derived under which the average abundance of the more cooperative strategy exceeds 50%. The second model considers a situation in which individuals start defecting towards others that are not similar to them. This situation is termed “defective tags”. It is shown that in this case, individuals using tags to cooperate exclusively with their own kind dominate over unconditional cooperators.

  20. 75 FR 76055 - Nebraska Public Power District Cooper Nuclear Station; Notice of Issuance of Renewed Facility...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-07

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Docket No. 50-298; NRC-2008-0617] Nebraska Public Power District Cooper Nuclear Station; Notice of... operator of the Cooper Nuclear Station (CNS). Renewed facility operating license No. DPR-46...

  1. 47 CFR 95.33 - Cooperative use of radio stations in the GMRS.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 5 2013-10-01 2013-10-01 false Cooperative use of radio stations in the GMRS... SPECIAL RADIO SERVICES PERSONAL RADIO SERVICES General Mobile Radio Service (GMRS) § 95.33 Cooperative use of radio stations in the GMRS. (a) Licensees (a licensee is the entity to which the license is issued...

  2. 47 CFR 95.33 - Cooperative use of radio stations in the GMRS.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 5 2014-10-01 2014-10-01 false Cooperative use of radio stations in the GMRS... SPECIAL RADIO SERVICES PERSONAL RADIO SERVICES General Mobile Radio Service (GMRS) § 95.33 Cooperative use of radio stations in the GMRS. (a) Licensees (a licensee is the entity to which the license is issued...

  3. 47 CFR 95.33 - Cooperative use of radio stations in the GMRS.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 5 2012-10-01 2012-10-01 false Cooperative use of radio stations in the GMRS... SPECIAL RADIO SERVICES PERSONAL RADIO SERVICES General Mobile Radio Service (GMRS) § 95.33 Cooperative use of radio stations in the GMRS. (a) Licensees (a licensee is the entity to which the license is issued...

  4. 47 CFR 95.33 - Cooperative use of radio stations in the GMRS.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 5 2011-10-01 2011-10-01 false Cooperative use of radio stations in the GMRS... SPECIAL RADIO SERVICES PERSONAL RADIO SERVICES General Mobile Radio Service (GMRS) § 95.33 Cooperative use of radio stations in the GMRS. (a) Licensees (a licensee is the entity to which the license is issued...

  5. 78 FR 40519 - Cooper Nuclear Station; Application and Amendment to Facility Operating License Involving...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-05

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Cooper Nuclear Station; Application and Amendment to Facility Operating License Involving Proposed... No. DPR-46, issued to Nebraska Public Power District (the licensee), for operation of the...

  6. Cooperative Knowledge Bases.

    DTIC Science & Technology

    1988-02-01

    intellegent knowledge bases. The present state of our system for concurrent evaluation of a knowledge base of logic clauses using static allocation...de Kleer, J., An assumption-based TMS, Artificial Intelligence, Vol. 28, No. 2, 1986. [Doyle 79) Doyle, J. A truth maintenance system, Artificial

  7. Government-to-government cooperation in space station development

    NASA Technical Reports Server (NTRS)

    Nassiff, S. H.

    1985-01-01

    A memoranda of understanding was recently signed between the United States (NASA) and three international Space Station partners - Canada, European Space Agency (ESA), and Japan. The international partners are performing parallel Phase B preliminary design studies, concurrent with the U.S., on their proposed elements/systems for possible integration and operation with the U.S. Space Station System complex. During the 21-month Space Station Phase B study, a large amount of technical interface data will have to be transferred between the U.S. and the international partners. Scheduled bilateral technical coordination meetings will also be held. The coordination and large number of interfaces required to integrate the international requirements into the Space Station require a clean interface management organizational structure and operation procedures to accomplish the integration task. The international coordination management organizational structure, management tools, and communications network are discussed including the proposed international elements/systems being studied by the international partners.

  8. International Cooperation in the Field of International Space Station (ISS) Payload Safety

    NASA Technical Reports Server (NTRS)

    Heimann, Timothy; Larsen, Axel M.; Rose, Summer; Sgobba, Tommaso

    2005-01-01

    In the frame of the International Space Station (ISS) Program cooperation, in 1998, the European Space Agency (ESA) approached the National Aeronautics and Space Administration (NASA) with the unique concept of a Payload Safety Review Panel (PSRP) "franchise" based at the European Space Technology Center (ESTEC), where the panel would be capable of autonomously reviewing flight hardware for safety. This paper will recount the course of an ambitious idea as it progressed into a fully functional reality. It will show how a panel initially conceived at NASA to serve a national programme has evolved into an international safety cooperation asset. The PSRP established at NASA began reviewing ISS payloads approximately in late 1994 or early 1995 as an expansion of the pre-existing Shuttle Program PSRP. This paper briefly describes the fundamental Shuttle safety process and the establishment of the safety requirements for payloads intending to use the Space Transportation System and International Space Station (ISS). The paper will also offer some historical statistics about the experiments that completed the payload safety process for Shuttle and ISS. The paper 1 then presents the background of ISS agreements and international treaties that had to be taken into account when establishing the ESA PSRP. The detailed franchising model will be expounded upon, followed by an outline of the cooperation charter approved by the NASA Associate Administrator, Office of Space Flight, and ESA Director of Manned Spaceflight and Microgravity. The resulting ESA PSRP implementation and its success statistics to date will then be addressed. Additionally the paper presents the ongoing developments with the Japan Aerospace Exploration Agency. The discussion will conclude with ideas for future developments, such to achieve a fully integrated international system of payload safety panels for ISS.

  9. International Cooperation in the Field of International Space Station (ISS) Payload Safety

    NASA Technical Reports Server (NTRS)

    Heimann, Timothy; Larsen, Axel M.; Rose, Summer; Sgobba, Tommaso

    2005-01-01

    In the frame of the International Space Station (ISS) Program cooperation, in 1998, the European Space Agency (ESA) approached the National Aeronautics and Space Administration (NASA) with the unique concept of a Payload Safety Review Panel (PSRP) "franchise" based at the European Space Technology Center (ESTEC), where the panel would be capable of autonomously reviewing flight hardware for safety. This paper will recount the course of an ambitious idea as it progressed into a fully functional reality. It will show how a panel initially conceived at NASA to serve a national programme has evolved into an international safety cooperation asset. The PSRP established at NASA began reviewing ISS payloads approximately in late 1994 or early 1995 as an expansion of the pre-existing Shuttle Program PSRP. This paper briefly describes the fundamental Shuttle safety process and the establishment of the safety requirements for payloads intending to use the Space Transportation System and International Space Station (ISS). The paper will also offer some historical statistics about the experiments that completed the payload safety process for Shuttle and ISS. The paper 1 then presents the background of ISS agreements and international treaties that had to be taken into account when establishing the ESA PSRP. The detailed franchising model will be expounded upon, followed by an outline of the cooperation charter approved by the NASA Associate Administrator, Office of Space Flight, and ESA Director of Manned Spaceflight and Microgravity. The resulting ESA PSRP implementation and its success statistics to date will then be addressed. Additionally the paper presents the ongoing developments with the Japan Aerospace Exploration Agency. The discussion will conclude with ideas for future developments, such to achieve a fully integrated international system of payload safety panels for ISS.

  10. Teleprogramming a cooperative space robotic workcell for space station

    NASA Astrophysics Data System (ADS)

    Haule, Damian D.; Noorhosseini, S. M.; Malowany, Alfred S.

    1992-11-01

    The growing insight into the complexity and cost of in-orbit operations of future space missions strengthens the belief that a significant amount of automation will be needed to operate the orbital laboratories in a safe, efficient, and economic way. Thus, Automation & Robotics (A&R) technology is vital for unmanned exploration missions to comets and planets. While part of the space worksite may be structured, the space environment is generally unstructured. By `structured,' we mean environments that are designed and engineered to somehow `cooperate' with the machine. In addition, the structured part of the space worksite may be damaged or in an unknown condition. This lack of structure, as well as the non- repetitive nature of the tasks, require constant adaptation to the space environment by the robot. This is the motivation for increased space robot autonomy. However, complete autonomy is still beyond the scope of today's state-of-the-art in the case of a system executing a complete mission in a hazardous environment such as space. A systematic approach for the development of A&R technologies will reduce the lead-times and costs of facilities for recurrent basic tasks. A space robotic workcell (SRW) is a collection of robots, sensors, and other industrial equipment grouped in a cooperative environment to perform various complex tasks in space. Due to their distributed nature, the control and programming of SRWs is often a difficult task. The issues involved in order to design a real-time teleprogrammable SRW system that performs intervention tasks at remote unstructured sites are summarized. The concept of `remotely operated autonomous robots' (i.e., robots teleprogrammed and telesupervised at the task level while at a space worksite) is also developed via telepresence for human-machine interface and voice/speech programming. This paper makes an assessment of the role that teleprogramming may have in furthering the automation capabilities of space teleoperated

  11. Ideas for a Cooperative Software Development for Future GGOS Stations

    NASA Astrophysics Data System (ADS)

    Neidhardt, A.; Ettl, M.

    2012-12-01

    The development of software is a creative process, which offers a huge degree of freedom. In scientific fields a lot of researchers develop their own software for specific needs. Everyone has their own preferences and backgrounds regarding the used programming languages, styles, and platforms. This complexity results in software which is not always directly usable by others in the communities. In addition, the software is often error-prone as hidden bugs are not always revealed. Therefore ideas came up to solve these problems at the Geodetic Observatory Wettzell. The results were coding layouts and policies, documentation strategies, the usage of version control, and a consistent process of continuous integration. Within this, the discussed quality factors can define quality metrics which help to quantize code quality. The resulting software is a repository of tested modules that can be used in different programs for the geodetic space techniques. This is one possible contribution to future GGOS stations.

  12. 75 FR 10517 - Nebraska Public Power District, Cooper Nuclear Station; Exemption

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-08

    ... compliance date for all operating nuclear power plants, but noted that the Commission's regulations provide... COMMISSION Nebraska Public Power District, Cooper Nuclear Station; Exemption 1.0 Background Nebraska Public... licensed activities in nuclear power reactors against radiological sabotage,'' published in the Federal...

  13. Exploring Reputation-Based Cooperation:

    NASA Astrophysics Data System (ADS)

    Vilone, Daniele; Giardini, Francesca; Paolucci, Mario

    In dyadic models of indirect reciprocity, the receivers' history of giving has a significant impact on the donor's decision. When the interaction involves more than two agents things become more complicated, and in large groups cooperation can hardly emerge. In this work we use a Public Goods Game to investigate whether publicly available reputation scores may support the evolution of cooperation and whether this is affected by the kind of network structure adopted. Moreover, if agents interact on a bipartite graph with partner selection, cooperation can quickly thrive in large groups.

  14. Jigsaw Cooperative Learning: Acid-Base Theories

    ERIC Educational Resources Information Center

    Tarhan, Leman; Sesen, Burcin Acar

    2012-01-01

    This study focused on investigating the effectiveness of jigsaw cooperative learning instruction on first-year undergraduates' understanding of acid-base theories. Undergraduates' opinions about jigsaw cooperative learning instruction were also investigated. The participants of this study were 38 first-year undergraduates in chemistry education…

  15. Jigsaw Cooperative Learning: Acid-Base Theories

    ERIC Educational Resources Information Center

    Tarhan, Leman; Sesen, Burcin Acar

    2012-01-01

    This study focused on investigating the effectiveness of jigsaw cooperative learning instruction on first-year undergraduates' understanding of acid-base theories. Undergraduates' opinions about jigsaw cooperative learning instruction were also investigated. The participants of this study were 38 first-year undergraduates in chemistry education…

  16. The Emergence of Relationship-based Cooperation

    PubMed Central

    Xu, Bo; Wang, Jianwei

    2015-01-01

    This paper investigates the emergence of relationship-based cooperation by coupling two simple mechanisms into the model: tie strength based investment preference and homophily assumption. We construct the model by categorizing game participants into four types: prosocialists (players who prefers to invest in their intimate friends), antisocialists (players who prefer to invest in strangers), egoists (players who never cooperate) and altruists (players who cooperate indifferently with anyone). We show that the relationship-based cooperation (prosocialists) is favored throughout the evolution if we assume players of the same type have stronger ties than different ones. Moreover, we discover that strengthening the internal bonds within the strategic clusters further promotes the competitiveness of prosocialists and therefore facilitates the emergence of relationship-based cooperation in our proposed scenarios. The robustness of the model is also tested under different strategy updating rules and network structures. The results show that this argument is robust against the variations of initial conditions and therefore can be considered as a fundamental theoretical framework to study relationship-based cooperation in reality. PMID:26567904

  17. The Emergence of Relationship-based Cooperation

    NASA Astrophysics Data System (ADS)

    Xu, Bo; Wang, Jianwei

    2015-11-01

    This paper investigates the emergence of relationship-based cooperation by coupling two simple mechanisms into the model: tie strength based investment preference and homophily assumption. We construct the model by categorizing game participants into four types: prosocialists (players who prefers to invest in their intimate friends), antisocialists (players who prefer to invest in strangers), egoists (players who never cooperate) and altruists (players who cooperate indifferently with anyone). We show that the relationship-based cooperation (prosocialists) is favored throughout the evolution if we assume players of the same type have stronger ties than different ones. Moreover, we discover that strengthening the internal bonds within the strategic clusters further promotes the competitiveness of prosocialists and therefore facilitates the emergence of relationship-based cooperation in our proposed scenarios. The robustness of the model is also tested under different strategy updating rules and network structures. The results show that this argument is robust against the variations of initial conditions and therefore can be considered as a fundamental theoretical framework to study relationship-based cooperation in reality.

  18. Space Station Based Microacceleration Experiment Platform

    NASA Technical Reports Server (NTRS)

    Barber, Katy; Economopoulos, Tony; Evenson, Erik; Gonzalez, Raul; Henson, Steve; Parada, Enrique; Robinson, Rick; Scott, Mike; Spotz, Bill

    1990-01-01

    Normal Space Station Freedom activities, such as docking, astronauts' movement, equipment vibrations, and space station reboosts, exert forces on the structure, resulting in static or transient accelerations greater than many microgravity experiments can tolerate. A solution to this problem is to isolate experiments on a separate platform free from such disturbances. The Space Station Based Microacceleration Experiment Platform, a proposed solution to the Space Station microgravity experiment problem is described. It is modular in design and can be telerobotically assembled and operated. The Microacceleration Experiment Platform (MEP) consists of a minimum configuration platform to which power, propulsion, propellant, and experiment modules are added. The platform's layout is designed to take maximum advantage of the microgravity field structure in orbit.

  19. 47 CFR 95.139 - Adding a small base station or a small control station.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 5 2011-10-01 2011-10-01 false Adding a small base station or a small control... SPECIAL RADIO SERVICES PERSONAL RADIO SERVICES General Mobile Radio Service (GMRS) § 95.139 Adding a small... or more small base stations or a small control station may be added to a GMRS system at any...

  20. 47 CFR 95.139 - Adding a small base station or a small control station.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 5 2013-10-01 2013-10-01 false Adding a small base station or a small control... SPECIAL RADIO SERVICES PERSONAL RADIO SERVICES General Mobile Radio Service (GMRS) § 95.139 Adding a small... or more small base stations or a small control station may be added to a GMRS system at any...

  1. 47 CFR 95.139 - Adding a small base station or a small control station.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Adding a small base station or a small control... SPECIAL RADIO SERVICES PERSONAL RADIO SERVICES General Mobile Radio Service (GMRS) § 95.139 Adding a small... or more small base stations or a small control station may be added to a GMRS system at any...

  2. 47 CFR 95.139 - Adding a small base station or a small control station.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 5 2014-10-01 2014-10-01 false Adding a small base station or a small control... SPECIAL RADIO SERVICES PERSONAL RADIO SERVICES General Mobile Radio Service (GMRS) § 95.139 Adding a small... or more small base stations or a small control station may be added to a GMRS system at any...

  3. 47 CFR 95.139 - Adding a small base station or a small control station.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 5 2012-10-01 2012-10-01 false Adding a small base station or a small control... SPECIAL RADIO SERVICES PERSONAL RADIO SERVICES General Mobile Radio Service (GMRS) § 95.139 Adding a small... or more small base stations or a small control station may be added to a GMRS system at any...

  4. Agent-Based Cooperative Control

    DTIC Science & Technology

    2005-12-01

    518. [91] A. Robertson, G. Inalhan, J. P. How, “ Formation control strategies for a separated spacecraft interferometer,” in Proc. of the 1999...100] M. Tillerson and J. P. How, “Advanced guidance algorithms for spacecraft formation -keeping,” in Proc. of the 2002 American Control Conference...based nonlinear control theory. Potential Field Addresses: issues of desired interaction such as coordination, formation , and collision

  5. Lunar base thermoelectric power station study

    NASA Technical Reports Server (NTRS)

    Determan, William; Frye, Patrick; Mondt, Jack; Fleurial, Jean-Pierre; Johnson, Ken; Stapfer, G.; Brooks, Michael D.; Heshmatpour, Ben

    2006-01-01

    Under NASA's Project Prometheus, the Nuclear Systems Program, the Jet Propulsion Laboratory, Pratt & Whitney Rocketdyne, and Teledyne Energy Systems have teamed with a number of universities, under the Segmented Thermoelectric Multicouple Converter (STMC) program, to develop the next generation of advanced thermoelectric converters for space reactor power systems. Work on the STMC converter assembly has progressed to the point where the lower temperature stage of the segmented multicouple converter assembly is ready for laboratory testing and the upper stage materials have been identified and their properties are being characterized. One aspect of the program involves mission application studies to help define the potential benefits from the use of these STMC technologies for designated NASA missions such as the lunar base power station where kilowatts of power are required to maintain a permanent manned presence on the surface of the moon. A modular 50 kWe thermoelectric power station concept was developed to address a specific set of requirements developed for this mission. Previous lunar lander concepts had proposed the use of lunar regolith as in-situ radiation shielding material for a reactor power station with a one kilometer exclusion zone radius to minimize astronaut radiation dose rate levels. In the present concept, we will examine the benefits and requirements for a hermetically-sealed reactor thermoelectric power station module suspended within a man-made lunar surface cavity. The concept appears to maximize the shielding capabilities of the lunar regolith while minimizing its handling requirements. Both thermal and nuclear radiation levels from operation of the station, at its 100-m exclusion zone radius, were evaluated and found to be acceptable. Site preparation activities are reviewed and well as transport issues for this concept. The goal of the study was to review the entire life cycle of the unit to assess its technical problems and technology

  6. Lunar Base Thermoelectric Power Station Study

    SciTech Connect

    Determan, William; Frye, Patrick; Mondt, Jack; Fleurial, Jean-Pierre; Johnson, Ken; Stapfer, Gerhard; Brooks, Michael; Heshmatpour, Ben

    2006-01-20

    Under NASA's Project Prometheus, the Nuclear Space Power Systems Program, the Jet Propulsion Laboratory, Pratt and Whitney Rocketdyne, and Teledyne Energy Systems have teamed with a number of universities, under the Segmented Thermoelectric Multicouple Converter (STMC) Task, to develop the next generation of advanced thermoelectric converters for space reactor power systems. Work on the STMC converter assembly has progressed to the point where the lower temperature stage of the segmented multicouple converter assembly is ready for laboratory testing, and promising candidates for the upper stage materials have been identified and their properties are being characterized. One aspect of the program involves mission application studies to help define the potential benefits from the use of these STMC technologies for designated NASA missions such as a lunar base power station where kilowatts of power would be required to maintain a permanent manned presence on the surface of the moon. A modular 50 kWe thermoelectric power station concept was developed to address a specific set of requirements developed for this particular mission concept. Previous lunar lander concepts had proposed the use of lunar regolith as in-situ radiation shielding material for a reactor power station with a one kilometer exclusion zone radius to minimize astronaut radiation dose rate levels. In the present concept, we will examine the benefits and requirements for a hermetically-sealed reactor thermoelectric power station module suspended within a man-made lunar surface cavity. The concept appears to maximize the shielding capabilities of the lunar regolith while minimizing its handling requirements. Both thermal and nuclear radiation levels from operation of the station, at its 100-m exclusion zone radius, were evaluated and found to be acceptable. Site preparation activities are reviewed as well as transport issues for this concept. The goal of the study was to review the entire life cycle of

  7. Lunar Base Thermoelectric Power Station Study

    NASA Astrophysics Data System (ADS)

    Determan, William; Frye, Patrick; Mondt, Jack; Fleurial, Jean-Pierre; Johnson, Ken; Stapfer, Gerhard; Brooks, Michael; Heshmatpour, Ben

    2006-01-01

    Under NASA's Project Prometheus, the Nuclear Space Power Systems Program, the Jet Propulsion Laboratory, Pratt & Whitney Rocketdyne, and Teledyne Energy Systems have teamed with a number of universities, under the Segmented Thermoelectric Multicouple Converter (STMC) Task, to develop the next generation of advanced thermoelectric converters for space reactor power systems. Work on the STMC converter assembly has progressed to the point where the lower temperature stage of the segmented multicouple converter assembly is ready for laboratory testing, and promising candidates for the upper stage materials have been identified and their properties are being characterized. One aspect of the program involves mission application studies to help define the potential benefits from the use of these STMC technologies for designated NASA missions such as a lunar base power station where kilowatts of power would be required to maintain a permanent manned presence on the surface of the moon. A modular 50 kWe thermoelectric power station concept was developed to address a specific set of requirements developed for this particular mission concept. Previous lunar lander concepts had proposed the use of lunar regolith as in-situ radiation shielding material for a reactor power station with a one kilometer exclusion zone radius to minimize astronaut radiation dose rate levels. In the present concept, we will examine the benefits and requirements for a hermetically-sealed reactor thermoelectric power station module suspended within a man-made lunar surface cavity. The concept appears to maximize the shielding capabilities of the lunar regolith while minimizing its handling requirements. Both thermal and nuclear radiation levels from operation of the station, at its 100-m exclusion zone radius, were evaluated and found to be acceptable. Site preparation activities are reviewed as well as transport issues for this concept. The goal of the study was to review the entire life cycle of the

  8. Lunar base thermoelectric power station study

    NASA Technical Reports Server (NTRS)

    Determan, William; Frye, Patrick; Mondt, Jack; Fleurial, Jean-Pierre; Johnson, Ken; Stapfer, G.; Brooks, Michael D.; Heshmatpour, Ben

    2006-01-01

    Under NASA's Project Prometheus, the Nuclear Systems Program, the Jet Propulsion Laboratory, Pratt & Whitney Rocketdyne, and Teledyne Energy Systems have teamed with a number of universities, under the Segmented Thermoelectric Multicouple Converter (STMC) program, to develop the next generation of advanced thermoelectric converters for space reactor power systems. Work on the STMC converter assembly has progressed to the point where the lower temperature stage of the segmented multicouple converter assembly is ready for laboratory testing and the upper stage materials have been identified and their properties are being characterized. One aspect of the program involves mission application studies to help define the potential benefits from the use of these STMC technologies for designated NASA missions such as the lunar base power station where kilowatts of power are required to maintain a permanent manned presence on the surface of the moon. A modular 50 kWe thermoelectric power station concept was developed to address a specific set of requirements developed for this mission. Previous lunar lander concepts had proposed the use of lunar regolith as in-situ radiation shielding material for a reactor power station with a one kilometer exclusion zone radius to minimize astronaut radiation dose rate levels. In the present concept, we will examine the benefits and requirements for a hermetically-sealed reactor thermoelectric power station module suspended within a man-made lunar surface cavity. The concept appears to maximize the shielding capabilities of the lunar regolith while minimizing its handling requirements. Both thermal and nuclear radiation levels from operation of the station, at its 100-m exclusion zone radius, were evaluated and found to be acceptable. Site preparation activities are reviewed and well as transport issues for this concept. The goal of the study was to review the entire life cycle of the unit to assess its technical problems and technology

  9. Antenna unit and radio base station therewith

    DOEpatents

    Kuwahara, Mikio; Doi, Nobukazu; Suzuki, Toshiro; Ishida, Yuji; Inoue, Takashi; Niida, Sumaru

    2007-04-10

    Phase and amplitude deviations, which are generated, for example, by cables connecting an array antenna of a CDMA base station and the base station, are calibrated in the baseband. The base station comprises: an antenna apparatus 1; couplers 2; an RF unit 3 that converts a receive signal to a baseband signal, converts a transmit signal to a radio frequency, and performs power control; an A/D converter 4 for converting a receive signal to a digital signal; a receive beam form unit 6 that multiplies the receive signal by semi-fixed weight; a despreader 7 for this signal input; a time-space demodulator 8 for demodulating user data; a despreader 9 for probe signal; a space modulator 14 for user data; a spreader 13 for user signal; a channel combiner 12; a Tx calibrater 11 for controlling calibration of a signal; a D/A converter 10; a unit 16 for calculation of correlation matrix for generating a probe signal used for controlling an Rx calibration system and a TX calibration system; a spreader 17 for probe signal; a power control unit 18; a D/A converter 19; an RF unit 20 for probe signal; an A/D converter 21 for signal from the couplers 2; and a despreader 22.

  10. Cooperating knowledge-based systems

    NASA Technical Reports Server (NTRS)

    Feigenbaum, Edward A.; Buchanan, Bruce G.

    1988-01-01

    This final report covers work performed under Contract NCC2-220 between NASA Ames Research Center and the Knowledge Systems Laboratory, Stanford University. The period of research was from March 1, 1987 to February 29, 1988. Topics covered were as follows: (1) concurrent architectures for knowledge-based systems; (2) methods for the solution of geometric constraint satisfaction problems, and (3) reasoning under uncertainty. The research in concurrent architectures was co-funded by DARPA, as part of that agency's Strategic Computing Program. The research has been in progress since 1985, under DARPA and NASA sponsorship. The research in geometric constraint satisfaction has been done in the context of a particular application, that of determining the 3-D structure of complex protein molecules, using the constraints inferred from NMR measurements.

  11. Distributed, cooperating knowledge-based systems

    NASA Technical Reports Server (NTRS)

    Truszkowski, Walt

    1991-01-01

    Some current research in the development and application of distributed, cooperating knowledge-based systems technology is addressed. The focus of the current research is the spacecraft ground operations environment. The underlying hypothesis is that, because of the increasing size, complexity, and cost of planned systems, conventional procedural approaches to the architecture of automated systems will give way to a more comprehensive knowledge-based approach. A hallmark of these future systems will be the integration of multiple knowledge-based agents which understand the operational goals of the system and cooperate with each other and the humans in the loop to attain the goals. The current work includes the development of a reference model for knowledge-base management, the development of a formal model of cooperating knowledge-based agents, the use of testbed for prototyping and evaluating various knowledge-based concepts, and beginning work on the establishment of an object-oriented model of an intelligent end-to-end (spacecraft to user) system. An introductory discussion of these activities is presented, the major concepts and principles being investigated are highlighted, and their potential use in other application domains is indicated.

  12. Cooperating expert systems for Space Station - Power/thermal subsystem testbeds

    NASA Technical Reports Server (NTRS)

    Wong, Carla M.; Weeks, David J.; Sundberg, Gale R.; Healey, Kathleen L.; Dominick, Jeffrey S.

    1988-01-01

    The Systems Autonomy Demonstration Project (SADP) is a NASA-sponsored series of increasingly complex demonstrations to show the benefits of integrating knowledge-based systems with conventional process control in real-time, real-world problem domains that can facilitate the operations and availability of major Space Station distributed systems. This paper describes the system design, objectives, approaches, and status of each of the testbed knowledge-based systems. Simplified schematics of the systems are shown.

  13. Assortative mating based on cooperativeness and generosity.

    PubMed

    Tognetti, A; Berticat, C; Raymond, M; Faurie, C

    2014-05-01

    Cooperative behaviour and generosity towards nonkin represent costly and risky behaviour that could be used as a signal of mate quality. Therefore, cooperative traits could serve as criteria in mate choice, leading to assortative mating for those traits. There is evidence of similarity in couples for altruistic traits. However, the literature is based on self-reports and does not provide conclusive proof of either a convergence across time or mating preferences. Here, we report a field experiment, conducted in rural villages in Senegal, showing that husbands and wives are similar with respect to their contributions to a public good and their charity donations. Further analyses suggest that this similarity is due to initial assortment rather than convergence of phenotypes.

  14. Cooperation.

    ERIC Educational Resources Information Center

    Online-Offline, 1997

    1997-01-01

    The theme of this month's issue is "cooperation"--related to animal, personal, national, and global cooperation; rules and regulations; and team efforts. K-8 resources on the theme include World Wide Web sites, CD-ROM, software, videos, books, and others. Features include cooperative living, alliances of nations, songs of cooperation, and animals…

  15. Ameliorated GA approach for base station planning

    NASA Astrophysics Data System (ADS)

    Wang, Andong; Sun, Hongyue; Wu, Xiaomin

    2011-10-01

    In this paper, we aim at locating base station (BS) rationally to satisfy the most customs by using the least BSs. An ameliorated GA is proposed to search for the optimum solution. In the algorithm, we mesh the area to be planned according to least overlap length derived from coverage radius, bring into isometric grid encoding method to represent BS distribution as well as its number and develop select, crossover and mutation operators to serve our unique necessity. We also construct our comprehensive object function after synthesizing coverage ratio, overlap ratio, population and geographical conditions. Finally, after importing an electronic map of the area to be planned, a recommended strategy draft would be exported correspondingly. We eventually import HongKong, China to simulate and yield a satisfactory solution.

  16. NASA space station automation: AI-based technology review

    NASA Technical Reports Server (NTRS)

    Firschein, O.; Georgeff, M. P.; Park, W.; Neumann, P.; Kautz, W. H.; Levitt, K. N.; Rom, R. J.; Poggio, A. A.

    1985-01-01

    Research and Development projects in automation for the Space Station are discussed. Artificial Intelligence (AI) based automation technologies are planned to enhance crew safety through reduced need for EVA, increase crew productivity through the reduction of routine operations, increase space station autonomy, and augment space station capability through the use of teleoperation and robotics. AI technology will also be developed for the servicing of satellites at the Space Station, system monitoring and diagnosis, space manufacturing, and the assembly of large space structures.

  17. Amplification of Cooper pair splitting current in a graphene-based Cooper pair beam splitter geometry

    NASA Astrophysics Data System (ADS)

    Islam, SK Firoz; Saha, Arijit

    2017-09-01

    Motivated by the recent experiments [Scientific Reports 6, 23051 (2016), 10.1038/srep23051; Phys. Rev. Lett. 114, 096602 (2015), 10.1103/PhysRevLett.114.096602], we theoretically investigate Cooper pair splitting current in a graphene-based Cooper pair beam splitter geometry. By considering the graphene-based superconductor as an entangler device, instead of normal [two-dimensional (2D)] BCS superconductor, we show that the Cooper pair splitting current mediated by the crossed Andreev process is amplified compared to its normal superconductor counterpart. This amplification is attributed to the strong suppression of the local normal Andreev reflection process (arising from the Cooper pair splitting) from the graphene-based superconductor to lead via the same quantum dot, in comparison to the usual 2D superconductor. Due to the vanishing density of states at the Dirac point of undoped graphene, a doped graphene-based superconductor is considered here and it is observed that Cooper pair splitting current is very insensitive to the doping level in comparison to the usual 2D superconductor. The transport process of nonlocal spin-entangled electrons also depends on the type of pairing, i.e., whether the electron-hole pairing is onsite, intersublattice or the combination of both. The intersublattice pairing of graphene causes the maximum nonlocal Cooper pair splitting current, whereas the presence of both pairings reduces the Cooper pair splitting current.

  18. VIEW OF BASE END STATION BARLOW SHOWING THE SUGGESTED APPEARANCE ...

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

    VIEW OF BASE END STATION BARLOW SHOWING THE SUGGESTED APPEARANCE DURING USE (TOP IS NOT EXTANT INDICATING POST-USE DAMAGE), PACING NORTHWEST, VIEW IS OF THE FRONT, WITH THE RIGHT FRONT CORNER EXPOSED - White's Point Reservation, Base End Stations, B"1, Bounded by Voyager Circle & Mariner Drive, San Pedro, Los Angeles County, CA

  19. A vision-based telerobotic control station

    NASA Technical Reports Server (NTRS)

    Tillotson, Brian

    1990-01-01

    A telerobotic control station is described. In it, a machine vision system measures the position, orientation, and configuration of a user's hand. A robotic manipulator mirrors the status of the hand. This concept has two benefits: control actions are intuitive and easily learned, and the workstation requires little volume or mass.

  20. Installation of Ohio's First Electrolysis-Based Hydrogen Fueling Station

    NASA Technical Reports Server (NTRS)

    Scheidegger, Brianne T.; Lively, Michael L.

    2012-01-01

    This paper describes progress made towards the installation of a hydrogen fueling station in Northeast Ohio. In collaboration with several entities in the Northeast Ohio area, the NASA Glenn Research Center is installing a hydrogen fueling station that uses electrolysis to generate hydrogen on-site. The installation of this station is scheduled for the spring of 2012 at the Greater Cleveland Regional Transit Authority s Hayden bus garage in East Cleveland. This will be the first electrolysis-based hydrogen fueling station in Ohio.

  1. Cooperative Secure Data Aggregation in Sensor Networks Using Elliptic Curve Based Cryptosystems

    NASA Astrophysics Data System (ADS)

    Lin, Hua-Yi; Chiang, Tzu-Chiang

    Remote sensing infrastructures are now in widespread use to acquire detected information. Since the deployed nodes are separated, they need to cooperatively communicate sensed data to the base station, as shown in Fig.1. Additionally, the carried information probably contains confidential data. However, the properties of wireless communications are vulnerable to an exposed environment. Hence, secure data transmissions for cooperative information integration in sensor networks are essential. In general, wireless sensor nodes have limited resources, and they cannot provide sufficient CPU, memory and bandwidth to address complex operations. The proposed scheme depends on Discrete Logarithm Problem (DLP) of Elliptic Curve Cryptography (ECC), and exploits a smaller key size to achieve comparable security levels than Rivest Shamir Adleman (RSA) and Diffie-Hellman (DH) cryptosystems. Consequently, this paper exploits Elliptic Curve Diffie-Hellman (ECDH) based security methods to achieve cooperative secure information integration.

  2. The Concept of Photonics-Based Virtual Ground Tracking Station

    NASA Astrophysics Data System (ADS)

    Liu, Y.; Cong, B.; Nie, Y. M.; He, J.; Wang, X. Q.

    2016-02-01

    In this paper, we propose the concept of virtual ground tracking station for space missions. Based on microwave photonics, the virtual tracking station can realize spatial diversity, antenna arraying, dynamic resource allocation and distributed signal processing. Compared with conventional design, the flexibility, efficiency and performance can be significantly improved.

  3. Space station accommodations for lunar base elements: A study

    NASA Technical Reports Server (NTRS)

    Weidman, Deene J.; Cirillo, William; Llewellyn, Charles; Kaszubowski, Martin; Kienlen, E. Michael, Jr.

    1987-01-01

    The results of a study conducted at NASA-LaRC to assess the impact on the space station of accommodating a Manned Lunar Base are documented. Included in the study are assembly activities for all infrastructure components, resupply and operations support for lunar base elements, crew activity requirements, the effect of lunar activities on Cape Kennedy operations, and the effect on space station science missions. Technology needs to prepare for such missions are also defined. Results of the study indicate that the space station can support the manned lunar base missions with the addition of a Fuel Depot Facility and a heavy lift launch vehicle to support the large launch requirements.

  4. Social Networks-Based Adaptive Pairing Strategy for Cooperative Learning

    ERIC Educational Resources Information Center

    Chuang, Po-Jen; Chiang, Ming-Chao; Yang, Chu-Sing; Tsai, Chun-Wei

    2012-01-01

    In this paper, we propose a grouping strategy to enhance the learning and testing results of students, called Pairing Strategy (PS). The proposed method stems from the need of interactivity and the desire of cooperation in cooperative learning. Based on the social networks of students, PS provides members of the groups to learn from or mimic…

  5. Marketing Education Cooperative Education Manual. Classroom and Training Station Connecting Activities

    ERIC Educational Resources Information Center

    Ohio Department of Education, 2004

    2004-01-01

    Cooperative Education is a teaching method which uses real life work experiences to teach and/or reinforce competencies from the Marketing Content Standards. Direct connections are made between classroom instruction and workplace activities. The activities in this manual can be used to reinforce and contextualize content taught in the classroom…

  6. The Space Station Freedom - International cooperation and innovation in space safety

    NASA Technical Reports Server (NTRS)

    Rodney, George A.

    1989-01-01

    The Space Station Freedom (SSF) being developed by the United States, European Space Agency (ESA), Japan, and Canada poses novel safety challenges in design, operations, logistics, and program management. A brief overview discloses many features that make SSF a radical departure from earlier low earth orbit (LEO) space stations relative to safety management: size and power levels; multiphase manned assembly; 30-year planned lifetime, with embedded 'hooks and scars' forevolution; crew size and skill-mix variability; sustained logistical dependence; use of man, robotics and telepresence for on-orbit maintenance of station and free-flyer systems; closed-environment recycling; use of automation and expert systems; long-term operation of collocated life-sciences and materials-science experiments, requiring control and segregation of hazardous and chemically incompatible materials; and materials aging in space.

  7. The Space Station Freedom - International cooperation and innovation in space safety

    NASA Technical Reports Server (NTRS)

    Rodney, George A.

    1989-01-01

    The Space Station Freedom (SSF) being developed by the United States, European Space Agency (ESA), Japan, and Canada poses novel safety challenges in design, operations, logistics, and program management. A brief overview discloses many features that make SSF a radical departure from earlier low earth orbit (LEO) space stations relative to safety management: size and power levels; multiphase manned assembly; 30-year planned lifetime, with embedded 'hooks and scars' forevolution; crew size and skill-mix variability; sustained logistical dependence; use of man, robotics and telepresence for on-orbit maintenance of station and free-flyer systems; closed-environment recycling; use of automation and expert systems; long-term operation of collocated life-sciences and materials-science experiments, requiring control and segregation of hazardous and chemically incompatible materials; and materials aging in space.

  8. Electromagnetic field pattern in the environment of GSM base stations.

    PubMed

    Aniołczyk, H

    1999-01-01

    Three mobile phone systems are used in Poland: analog, operated at the 450 MHz frequency range, and two digital systems operated at 900 MHz and 1800 MHz. The GSM--Global System for Mobile Communication meets all relevant requirements, and it is most widely used throughout the world. According to the mobile phone concept, the whole communication area is divided into sub-areas (cells) where base stations are located. The base stations are provided with the transmitter units mounted on free-standing masts, high chimneys and building roofs, including those of the residential buildings. The transmitter antennas of the base stations constitute a source of 935-960 EMF radiation. This work analyses the essential characteristics of the base station antennas from the point of view of radiation intensity. The analysis is based on the results of EMF measurements performed by experts of two relevant research institutes. For inaccessible antennas, the measurements were performed at the accredited laboratory.

  9. Aspiration-based partner switching boosts cooperation in social dilemmas.

    PubMed

    Li, Zhi; Yang, Zhihu; Wu, Te; Wang, Long

    2014-01-01

    Most previous studies concerning linking dynamics often assumed that links pairing individuals should be identified and treated differently during topology adjusting procedure, in order to promote cooperation. A common assumption was that cooperators were expected to avoid being exploited by quickly breaking up relationships with defectors. Then the so-called prosocial links linking two cooperators (abbreviated as CC links hereafter) would be much favored by evolution, whereby cooperation was promoted. However, we suggest that this is not always necessary. Here, we developed a minimal model in which an aspiration-based partner switching mechanism was embedded to regulate the evolution of cooperation in social dilemmas. Individuals adjusted social ties in a self-questioning manner in line with the learning theory. Less game information was involved during dynamic linking and all links were tackled anonymously irrespective of their types (i.e., CD links, DD links, or CC links). The main results indicate that cooperation flourishes for a broad range of parameters. The denser the underlying network, the more difficult the evolution of cooperation. More importantly, moderate aspirations do much better in promoting the evolution of altruistic behavior and for most cases there exists the optimal aspiration level that most benefits cooperation. Too strong or too weak selection intensity turns out to be pretty conducive to the evolution of cooperation in such a dynamical system.

  10. Cooperative UAV-Based Communications Backbone for Sensor Networks

    SciTech Connect

    Roberts, R S

    2001-10-07

    The objective of this project is to investigate the use of unmanned air vehicles (UAVs) as mobile, adaptive communications backbones for ground-based sensor networks. In this type of network, the UAVs provide communication connectivity to sensors that cannot communicate with each other because of terrain, distance, or other geographical constraints. In these situations, UAVs provide a vertical communication path for the sensors, thereby mitigating geographic obstacles often imposed on networks. With the proper use of UAVs, connectivity to a widely disbursed sensor network in rugged terrain is readily achieved. Our investigation has focused on networks where multiple cooperating UAVs are used to form a network backbone. The advantage of using multiple UAVs to form the network backbone is parallelization of sensor connectivity. Many widely spaced or isolated sensors can be connected to the network at once using this approach. In these networks, the UAVs logically partition the sensor network into sub-networks (subnets), with one UAV assigned per subnet. Partitioning the network into subnets allows the UAVs to service sensors in parallel thereby decreasing the sensor-to-network connectivity. A UAV services sensors in its subnet by flying a route (path) through the subnet, uplinking data collected by the sensors, and forwarding the data to a ground station. An additional advantage of using multiple UAVs in the network is that they provide redundancy in the communications backbone, so that the failure of a single UAV does not necessarily imply the loss of the network.

  11. Quantum key distribution using card, base station and trusted authority

    SciTech Connect

    Nordholt, Jane Elizabeth; Hughes, Richard John; Newell, Raymond Thorson; Peterson, Charles Glen; Rosenberg, Danna; McCabe, Kevin Peter; Tyagi, Kush T; Dallman, Nicholas

    2015-04-07

    Techniques and tools for quantum key distribution ("QKD") between a quantum communication ("QC") card, base station and trusted authority are described herein. In example implementations, a QC card contains a miniaturized QC transmitter and couples with a base station. The base station provides a network connection with the trusted authority and can also provide electric power to the QC card. When coupled to the base station, after authentication by the trusted authority, the QC card acquires keys through QKD with a trusted authority. The keys can be used to set up secure communication, for authentication, for access control, or for other purposes. The QC card can be implemented as part of a smart phone or other mobile computing device, or the QC card can be used as a fillgun for distribution of the keys.

  12. Quantum key distribution using card, base station and trusted authority

    DOEpatents

    Nordholt, Jane E.; Hughes, Richard John; Newell, Raymond Thorson; Peterson, Charles Glen; Rosenberg, Danna; McCabe, Kevin Peter; Tyagi, Kush T.; Dallmann, Nicholas

    2017-06-14

    Techniques and tools for quantum key distribution ("QKD") between a quantum communication ("QC") card, base station and trusted authority are described herein. In example implementations, a QC card contains a miniaturized QC transmitter and couples with a base station. The base station provides a network connection with the trusted authority and can also provide electric power to the QC card. When coupled to the base station, after authentication by the trusted authority, the QC card acquires keys through QKD with a trust authority. The keys can be used to set up secure communication, for authentication, for access control, or for other purposes. The QC card can be implemented as part of a smart phone or other mobile computing device, or the QC card can be used as a fillgun for distribution of the keys.

  13. Evolution of cooperation driven by social-welfare-based migration

    NASA Astrophysics Data System (ADS)

    Li, Yan; Ye, Hang; Zhang, Hong

    2016-03-01

    Individuals' migration behavior may play a significant role in the evolution of cooperation. In reality, individuals' migration behavior may depend on their perceptions of social welfare. To study the relationship between social-welfare-based migration and the evolution of cooperation, we consider an evolutionary prisoner's dilemma game (PDG) in which an individual's migration depends on social welfare but not on the individual's own payoff. By introducing three important social welfare functions (SWFs) that are commonly studied in social science, we find that social-welfare-based migration can promote cooperation under a wide range of parameter values. In addition, these three SWFs have different effects on cooperation, especially through the different spatial patterns formed by migration. Because the relative efficiency of the three SWFs will change if the parameter values are changed, we cannot determine which SWF is optimal for supporting cooperation. We also show that memory capacity, which is needed to evaluate individual welfare, may affect cooperation levels in opposite directions under different SWFs. Our work should be helpful for understanding the evolution of human cooperation and bridging the chasm between studies of social preferences and studies of social cooperation.

  14. Human cooperation based on punishment reputation.

    PubMed

    dos Santos, Miguel; Rankin, Daniel J; Wedekind, Claus

    2013-08-01

    The threat of punishment usually promotes cooperation. However, punishing itself is costly, rare in nonhuman animals, and humans who punish often finish with low payoffs in economic experiments. The evolution of punishment has therefore been unclear. Recent theoretical developments suggest that punishment has evolved in the context of reputation games. We tested this idea in a simple helping game with observers and with punishment and punishment reputation (experimentally controlling for other possible reputational effects). We show that punishers fully compensate their costs as they receive help more often. The more likely defection is punished within a group, the higher the level of within-group cooperation. These beneficial effects perish if the punishment reputation is removed. We conclude that reputation is key to the evolution of punishment.

  15. Environmental safety conditions for mobile base stations in Alexandria.

    PubMed

    el-Shal, W; el-Sebaie, O

    2000-01-01

    The use of wireless communications devices e.g. cellular phones is increasing rapidly all over the world and in Egypt as well. This translates into a potentially significant public health problem: how far is the risk associated with these devices? Another risk is expected from the cellular towers or base stations, which transmit and receive these electromagnetic waves. Usually, these base stations should be constructed over residential buildings to cover all areas. Considering the increased public awareness about electromagnetic fields (EMF) exposure associated with these towers, this work aimed at investigation and evaluation of authorized environmental safety conditions for some mobile base stations in different districts of Alexandria city. The different mobile base stations were investigated for 12 standard safety specifications of the buildings' roofs on which mobile base stations are constructed. Although some of the standard specifications in the examined base stations were in compliance with standard specifications, some items were not in a safe condition. Only base stations F & G had complete safe conditions for all investigated items because of being erected on lighting towers of a sports stadium. On the other hand, base stations C, D, E, I, J, K, L1 & L2 needed a raise in the height of the antennas over buildings' roofs of 1-4.5 m. However, base stations C, D, H, K, L1 & L2 may pose a risk to near living population and consequently the towers have to be moved away. The violating distances are 3, 5.5, 3, 4.5, 4, 3 meters, respectively, while the environmental standard is 6 m. Therefore, the towers should be moved away from these populated areas Nevertheless, guided directions should be constructed in all base stations to warn close living population. Safety regulations as well as frequent inspection need to be applied, on both Egyptian mobile phone companies, to ensure the application of all standard specifications. A significant research effort is needed

  16. Identifying a base network of federally funded streamgaging stations

    USGS Publications Warehouse

    Ries, Kernell G.; Kolva, J.R.; Stewart, D.W.

    2004-01-01

    The U.S. Geological Survey (USGS) has completed a preliminary analysis to identify streamgaging stations needed in a base network that would satisfy five primary Federal goals for collecting streamflow information. The five goals are (1) determining streamflow at interstate and international borders and at locations mandated by court decrees, (2) determining the streamflow component of water budgets for the major river basins of the Nation, (3) providing real-time streamflow information to the U.S. National Weather Service to support flood-forecasting activities, (4) providing streamflow information at locations of monitoring stations included in USGS national water-quality networks, and (5) providing streamflow information necessary for regionalization of streamflow characteristics and assessing potential long-term trends in streamflow associated with changes in climate. The analysis was done using a Geographic Information System. USGS headquarters staff made initial selections of stations that satisfied at least one of the five goals, and then staff in each of the 48 USGS district offices reviewed the selections, making suggestions for additions or changes based on detailed local knowledge of the streams in the area. The analysis indicated that 4,242 streamgaging stations are needed in the base network to meet the 5 Federal goals for streamflow information. Of these, 2,692 stations (63.5 percent) are currently operated by the USGS, 277 stations (6.5 percent) are currently operated by other agencies, 865 (20.4 percent) are discontinued USGS stations that need to be reactivated, and 408 (9.6 percent) are locations where new stations are needed. Copyright ASCE 2004.

  17. Mobile phone base stations-Effects on wellbeing and health.

    PubMed

    Kundi, Michael; Hutter, Hans-Peter

    2009-08-01

    Studying effects of mobile phone base station signals on health have been discouraged by authoritative bodies like WHO International EMF Project and COST 281. WHO recommended studies around base stations in 2003 but again stated in 2006 that studies on cancer in relation to base station exposure are of low priority. As a result only few investigations of effects of base station exposure on health and wellbeing exist. Cross-sectional investigations of subjective health as a function of distance or measured field strength, despite differences in methods and robustness of study design, found indications for an effect of exposure that is likely independent of concerns and attributions. Experimental studies applying short-term exposure to base station signals gave various results, but there is weak evidence that UMTS and to a lesser degree GSM signals reduce wellbeing in persons that report to be sensitive to such exposures. Two ecological studies of cancer in the vicinity of base stations report both a strong increase of incidence within a radius of 350 and 400m respectively. Due to the limitations inherent in this design no firm conclusions can be drawn, but the results underline the urgent need for a comprehensive investigation of this issue. Animal and in vitro studies are inconclusive to date. An increased incidence of DMBA induced mammary tumors in rats at a SAR of 1.4W/kg in one experiment could not be replicated in a second trial. Indications of oxidative stress after low-level in vivo exposure of rats could not be supported by in vitro studies of human fibroblasts and glioblastoma cells. From available evidence it is impossible to delineate a threshold below which no effect occurs, however, given the fact that studies reporting low exposure were invariably negative it is suggested that power densities around 0.5-1mW/m(2) must be exceeded in order to observe an effect. The meager data base must be extended in the coming years. The difficulties of investigating

  18. Reputation-based partner choice promotes cooperation in social networks

    NASA Astrophysics Data System (ADS)

    Fu, Feng; Hauert, Christoph; Nowak, Martin A.; Wang, Long

    2008-08-01

    We investigate the cooperation dynamics attributed to the interplay between the evolution of individual strategies and evolution of individual partnerships. We focus on the effect of reputation on an individual’s partner-switching process. We assume that individuals can either change their strategies by imitating their partners or adjust their partnerships based on local information about reputations. We manipulate the partner switching in two ways; that is, individuals can switch from the lowest reputation partners, either to their partners’ partners who have the highest reputation (i.e., ordering in partnership) or to others randomly chosen from the entire population (i.e., randomness in partnership). We show that when individuals are able to alter their behavioral strategies and their social interaction partnerships on the basis of reputation, cooperation can prevail. We find that the larger temptation to defect and the denser the partner network, the more frequently individuals need to shift their partnerships in order for cooperation to thrive. Furthermore, an increasing tendency of switching to partners’ partners is more likely to lead to a higher level of cooperation. We show that when reputation is absent in such partner-switching processes, cooperation is much less favored than that of the reputation involved. Moreover, we investigate the effect of discounting an individual’s reputation on the evolution of cooperation. Our results highlight the importance of the consideration of reputation (indirect reciprocity) on the promotion of cooperation when individuals can adjust their partnerships.

  19. Evolution of Cooperation Driven by Reputation-Based Migration

    PubMed Central

    Cong, Rui; Wu, Bin; Qiu, Yuanying; Wang, Long

    2012-01-01

    How cooperation emerges and is stabilized has been a puzzling problem to biologists and sociologists since Darwin. One of the possible answers to this problem lies in the mobility patterns. These mobility patterns in previous works are either random-like or driven by payoff-related properties such as fitness, aspiration, or expectation. Here we address another force which drives us to move from place to place: reputation. To this end, we propose a reputation-based model to explore the effect of migration on cooperation in the contest of the prisoner's dilemma. In this model, individuals earn their reputation scores through previous cooperative behaviors. An individual tends to migrate to a new place if he has a neighborhood of low reputation. We show that cooperation is promoted for relatively large population density and not very large temptation to defect. A higher mobility sensitivity to reputation is always better for cooperation. A longer reputation memory favors cooperation, provided that the corresponding mobility sensitivity to reputation is strong enough. The microscopic perception of the effect of this mechanism is also given. Our results may shed some light on the role played by migration in the emergence and persistence of cooperation. PMID:22615739

  20. Evolution of cooperation driven by reputation-based migration.

    PubMed

    Cong, Rui; Wu, Bin; Qiu, Yuanying; Wang, Long

    2012-01-01

    How cooperation emerges and is stabilized has been a puzzling problem to biologists and sociologists since Darwin. One of the possible answers to this problem lies in the mobility patterns. These mobility patterns in previous works are either random-like or driven by payoff-related properties such as fitness, aspiration, or expectation. Here we address another force which drives us to move from place to place: reputation. To this end, we propose a reputation-based model to explore the effect of migration on cooperation in the contest of the prisoner's dilemma. In this model, individuals earn their reputation scores through previous cooperative behaviors. An individual tends to migrate to a new place if he has a neighborhood of low reputation. We show that cooperation is promoted for relatively large population density and not very large temptation to defect. A higher mobility sensitivity to reputation is always better for cooperation. A longer reputation memory favors cooperation, provided that the corresponding mobility sensitivity to reputation is strong enough. The microscopic perception of the effect of this mechanism is also given. Our results may shed some light on the role played by migration in the emergence and persistence of cooperation.

  1. Reputation-based partner choice promotes cooperation in social networks.

    PubMed

    Fu, Feng; Hauert, Christoph; Nowak, Martin A; Wang, Long

    2008-08-01

    We investigate the cooperation dynamics attributed to the interplay between the evolution of individual strategies and evolution of individual partnerships. We focus on the effect of reputation on an individual's partner-switching process. We assume that individuals can either change their strategies by imitating their partners or adjust their partnerships based on local information about reputations. We manipulate the partner switching in two ways; that is, individuals can switch from the lowest reputation partners, either to their partners' partners who have the highest reputation (i.e., ordering in partnership) or to others randomly chosen from the entire population (i.e., randomness in partnership). We show that when individuals are able to alter their behavioral strategies and their social interaction partnerships on the basis of reputation, cooperation can prevail. We find that the larger temptation to defect and the denser the partner network, the more frequently individuals need to shift their partnerships in order for cooperation to thrive. Furthermore, an increasing tendency of switching to partners' partners is more likely to lead to a higher level of cooperation. We show that when reputation is absent in such partner-switching processes, cooperation is much less favored than that of the reputation involved. Moreover, we investigate the effect of discounting an individual's reputation on the evolution of cooperation. Our results highlight the importance of the consideration of reputation (indirect reciprocity) on the promotion of cooperation when individuals can adjust their partnerships.

  2. Perception of mobile phone and base station risks.

    PubMed

    Siegrist, Michael; Earle, Timothy C; Gutscher, Heinz; Keller, Carmen

    2005-10-01

    Perceptions of risks associated with mobile phones, base stations, and other sources of electromagnetic fields (EMF) were examined. Data from a telephone survey conducted in the German- and French-speaking parts of Switzerland are presented (N = 1,015). Participants assessed both risks and benefits associated with nine different sources of EMF. Trust in the authorities regulating these hazards was assessed as well. In addition, participants answered a set of questions related to attitudes toward EMF and toward mobile phone base stations. According to respondents' assessments, high-voltage transmission lines are the most risky source of EMF. Mobile phones and mobile phone base stations received lower risk ratings. Results showed that trust in authorities was positively associated with perceived benefits and negatively associated with perceived risks. People who use their mobile phones frequently perceived lower risks and higher benefits than people who use their mobile phones infrequently. People who believed they lived close to a base station did not significantly differ in their level of risks associated with mobile phone base stations from people who did not believe they lived close to a base station. Regarding risk regulation, a majority of participants were in favor of fixing limiting values based on the worst-case scenario. Correlations suggest that belief in paranormal phenomena is related to level of perceived risks associated with EMF. Furthermore, people who believed that most chemical substances cause cancer also worried more about EMF than people who did not believe that chemical substances are that harmful. Practical implications of the results are discussed.

  3. Realization and capacity analysis of cooperative communications based on multiplexing

    NASA Astrophysics Data System (ADS)

    Zhao, Yao

    2008-04-01

    Cooperative communication (CC) techniques, which form virtual multiple input multiple output (MIMO) systems through cooperation among users, have been prevailing in current academic research. Two scenarios that have been mostly considered are one source to one destination with help from a classic relay node and two sources to one destination with cooperation among sources, i.e. cooperation for multiple access channels. In either case, single antenna is employed at each node. In this paper, I propose to realize cooperation based on multiplexing for a broadcast channel where there is one source equipped with multiple antennas and two destinations with single antenna. One of the destinations experiencing better channels helps the other destination under worse channel conditions by serving as a relay. Such a channel is referred to as a multiple input single output (MISO) cooperative broadcast channel (CBC). Further, I consider the capacity analysis for the MISO CBC where additive white Gaussian noise (AWGN) presents (MISO AWGN CBC), which is not easy because MISO AWGN channel, as a vector Gaussian channel, is generally not degraded. I derive an outer bound on the capacity region of MISO AWGN CBC to provide insights into its information transmission limit.

  4. Auction-based Security Game for Multiuser Cooperative Networks

    NASA Astrophysics Data System (ADS)

    Wang, An; Cai, Yueming; Yang, Wendong; Cheng, Yunpeng

    2013-04-01

    In this paper, we develop an auction-based algorithm to allocate the relay power efficiently to improve the system secrecy rate in a cooperative network, where several source-destination pairs and one cooperative relay are involved. On the one hand, the cooperative relay assists these pairs to transmit under a peak power constraint. On the other hand, the relay is untrusty and is also a passive eavesdropper. The whole auction process is completely distributed and no instantaneous channel state information exchange is needed. We also prove the existence and uniqueness of the Nash Equilibrium (NE) for the proposed power auction game. Moreover, the Pareto optimality is also validated. Simulation results show that our proposed auction-based algorithm can effectively improve the system secrecy rate. Besides, the proposed auction-based algorithm can converge to the unique NE point within a finite number of iterations. More interestingly, we also find that the proposed power auction mechanism is cheat-proof.

  5. International Cooperation in the Field of International Space Station Payload Safety: Overcoming Differences and Working for Future

    NASA Astrophysics Data System (ADS)

    Nakamura, Yasuhiro; Ozawa, Masayuki; Takeyasu, Yoshioka; Griffith, Gerald; Goto, Katsuhito; Mitsui, Masami

    2010-09-01

    The importance of international cooperation among the International Space Station(ISS) Program participants is ever increasing as the ISS nears assembly complete. In the field of payload safety assurance, NASA and JAXA have enhanced their cooperation level. The authors describe the evolution of cooperation between the two agencies and the challenges encountered and overcame. NASA and JAXA have been working toward development of a NASA Payload Safety Review Panel(PSRP) franchise panel at JAXA for several years. When the JAXA Safety Review Panel(SRP) becomes a fully franchised panel of the NASA PSRP, the JAXA SRP will have the authority review and approve all JAXA ISS payloads operated on USOS and JEM, although NASA and JAXA joint reviews may be conducted as necessary. A NASA PSRP franchised panel at JAXA will streamline the conventional review process. Japanese payload organizations will not have to go through both JAXA and NASA payload safety reviews, while NASA will be relieved of a certain amount of review activities. The persistent efforts have recently born fruit. For the past two years, NASA and JAXA have increased emphasis on efforts to develop a NASA PSRP Franchised Panel at JAXA with concrete results. In 2009, NASA and JAXA signed Charter and Joint Development Plan. At the end of 2009, NASA PSRP transferred some review responsibility to the JAXA SRP under the franchising charter. Although JAXA had long history of reviewing payloads by their own panel prior to NASA PSRP reviews, it took several years for JAXA to receive NASA PSRP approval for delegation of franchised review authority to JAXA. This paper discusses challenges JAXA and NAXA faced. Considerations were required in developing a franchise at JAXA for history and experiences of the JAXA SRP as well as language and cultural differences. The JAXA panel, not only had its own well-established processes and supporting organizational structures which had some differences from its NASA PSRP counterparts

  6. Knowledge-based machine vision systems for space station automation

    NASA Technical Reports Server (NTRS)

    Ranganath, Heggere S.; Chipman, Laure J.

    1989-01-01

    Computer vision techniques which have the potential for use on the space station and related applications are assessed. A knowledge-based vision system (expert vision system) and the development of a demonstration system for it are described. This system implements some of the capabilities that would be necessary in a machine vision system for the robot arm of the laboratory module in the space station. A Perceptics 9200e image processor, on a host VAXstation, was used to develop the demonstration system. In order to use realistic test images, photographs of actual space shuttle simulator panels were used. The system's capabilities of scene identification and scene matching are discussed.

  7. Receive Diversity Combining Techniques for SC-FDMA-Based Cooperative Relays

    NASA Astrophysics Data System (ADS)

    Woo, Kyung-Soo; Kim, Yeong-Jun; Yoo, Hyun-Il; Kim, Jaekwon; Yun, Sangboh; Cho, Yong-Soo

    In this letter, two receive diversity combining techniques are proposed for cooperative relay systems based on single-carrier frequency division multiple access (SC-FDMA) when relay station (RS) transmits the received signals from multiple mobile stations (MSs) together using one large size discrete Fourier transform (DFT). A simplified-MRC (S-MRC) technique performs diversity combining in the time-domain by using the estimated channel weights and initial estimates obtained by the SC-FDMA signal detector. An interference rejection-MRC (IR-MRC) technique performs diversity combining in the frequency-domain by adjusting the DFT spreading size at the receiver. It is shown by computer simulation that the proposed receive combining techniques achieve a significant diversity gain over the conventional techniques.

  8. 47 CFR 90.1331 - Restrictions on the operation of base and fixed stations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...-3700 MHz Band § 90.1331 Restrictions on the operation of base and fixed stations. (a)(1) Except as provided in paragraph (a)(2) of this section, base and fixed stations may not be located within 150 km of... these stations are available at http://www.fcc.gov/ib/sd/3650/. (2) Base and fixed stations may be...

  9. A Literature-Based Cooperative Lesson for ESL.

    ERIC Educational Resources Information Center

    Cromwell-Hoffman, Carole; Sasser, Linda

    This cooperative lesson for students of English as a Second Language (ESL) has students from different cultural and language backgrounds write folk tales from their native cultures and compile them into a book. Each four-member team is constructed based on student variables, including ethnicity, personality, academic ability, language functioning,…

  10. Project-Based Learning in Geotechnics: Cooperative versus Collaborative Teamwork

    ERIC Educational Resources Information Center

    Pinho-Lopes, Margarida; Macedo, Joaquim

    2016-01-01

    Since 2007/2008 project-based learning models have been used to deliver two fundamental courses on Geotechnics in University of Aveiro, Portugal. These models have evolved and have encompassed either cooperative or collaborative teamwork. Using data collected in five editions of each course (Soil Mechanics I and Soil Mechanics II), the different…

  11. Project-Based Learning in Geotechnics: Cooperative versus Collaborative Teamwork

    ERIC Educational Resources Information Center

    Pinho-Lopes, Margarida; Macedo, Joaquim

    2016-01-01

    Since 2007/2008 project-based learning models have been used to deliver two fundamental courses on Geotechnics in University of Aveiro, Portugal. These models have evolved and have encompassed either cooperative or collaborative teamwork. Using data collected in five editions of each course (Soil Mechanics I and Soil Mechanics II), the different…

  12. Cooperative wireless network control based health and activity monitoring system.

    PubMed

    Prakash, R; Ganesh, A Balaji; Girish, Siva V

    2016-10-01

    A real-time cooperative communication based wireless network is presented for monitoring health and activity of an end-user in their environment. The cooperative communication offers better energy consumption and also an opportunity to aware the current location of a user non-intrusively. The link between mobile sensor node and relay node is dynamically established by using Received Signal Strength Indicator (RSSI) and Link Quality Indicator (LQI) based on adaptive relay selection scheme. The study proposes a Linear Acceleration based Transmission Power Decision Control (LA-TPDC) algorithm to further enhance the energy efficiency of cooperative communication. Further, the occurrences of false alarms are carefully prevented by introducing three stages of sequential warning system. The real-time experiments are carried-out by using the nodes, namely mobile sensor node, relay nodes and a destination node which are indigenously developed by using a CC430 microcontroller integrated with an in-built transceiver at 868 MHz. The wireless node performance characteristics, such as energy consumption, Signal-Noise ratio (SNR), Bit Error Rate (BER), Packet Delivery Ratio (PDR) and transmission offset are evaluated for all the participated nodes. The experimental results observed that the proposed linear acceleration based transmission power decision control algorithm almost doubles the battery life time than energy efficient conventional cooperative communication.

  13. Cooperation under predation risk: a data-based ESS analysis

    PubMed Central

    Parker, G. A.; Milinski, M.

    1997-01-01

    Two fish that jointly approach a predator in order to inspect it share the deadly risk of capture depending on the distance between them. Models are developed that seek ESS inspection distances of both single prey and pairs, based on experimental data of the risk that prey (sticklebacks) incur when they approach a predator (pike) to varying distances. Our analysis suggests that an optimal inspection distance can exist for a single fish, and for two equal fish behaving entirely cooperatively so as to maximize the fitness of the pair. Two equal fish inspecting cooperatively should inspect at an equal distance from the predator. The optimal distance is much closer to the predator for cooperative pairs than for single inspectors. However, optimal inspection for two equal fish behaving cooperatively operates across a rather narrow band of conditions relating to the benefits of cooperation. Evolutionarily stable inspection can also exist for two equal fish behaving non-cooperatively such that each acts to make a best reply (in terms of its personal fitness) to its opponent's strategy. Non-cooperative pairs should also inspect at equal distance from the pike. Unlike the 'single fish' and 'cooperative' optima, which are unique inspection distances, there exists a range of ESS inspection distances. If either fish chooses to move to any point in this zone, the best reply of its opponent is to match it (move exactly alongside). Unilateral forward movement in the 'match zone' may not be possible without some cooperation, but if the pair can 'agree' to move forward synchronously, maintaining equal distance, inspection will occur at the nearest point in this zone to the predator. This 'near threshold' is an ESS and is closer to the predator than the single fish optimum: pairs behaving almost selfishly can thus attain greater benefits from inspection by the protection gained from Hamilton's dilution effect. That pairs should inspect more closely than single fish conforms with

  14. Engineering graphics data entry for space station data base

    NASA Technical Reports Server (NTRS)

    Lacovara, R. C.

    1986-01-01

    The entry of graphical engineering data into the Space Station Data Base was examined. Discussed were: representation of graphics objects; representation of connectivity data; graphics capture hardware; graphics display hardware; site-wide distribution of graphics, and consolidation of tools and hardware. A fundamental assumption was that existing equipment such as IBM based graphics capture software and VAX networked facilities would be exploited. Defensible conclusions reached after study and simulations of use of these systems at the engineering level are: (1) existing IBM based graphics capture software is an adequate and economical means of entry of schematic and block diagram data for present and anticipated electronic systems for Space Station; (2) connectivity data from the aforementioned system may be incorporated into the envisioned Space Station Data Base with modest effort; (3) graphics and connectivity data captured on the IBM based system may be exported to the VAX network in a simple and direct fashion; (4) graphics data may be displayed site-wide on VT-125 terminals and lookalikes; (5) graphics hard-copy may be produced site-wide on various dot-matrix printers; and (6) the system may provide integrated engineering services at both the engineering and engineering management level.

  15. Engineering graphics data entry for space station data base

    NASA Technical Reports Server (NTRS)

    Lacovara, R. C.

    1986-01-01

    The entry of graphical engineering data into the Space Station Data Base was examined. Discussed were: representation of graphics objects; representation of connectivity data; graphics capture hardware; graphics display hardware; site-wide distribution of graphics, and consolidation of tools and hardware. A fundamental assumption was that existing equipment such as IBM based graphics capture software and VAX networked facilities would be exploited. Defensible conclusions reached after study and simulations of use of these systems at the engineering level are: (1) existing IBM based graphics capture software is an adequate and economical means of entry of schematic and block diagram data for present and anticipated electronic systems for Space Station; (2) connectivity data from the aforementioned system may be incorporated into the envisioned Space Station Data Base with modest effort; (3) graphics and connectivity data captured on the IBM based system may be exported to the VAX network in a simple and direct fashion; (4) graphics data may be displayed site-wide on VT-125 terminals and lookalikes; (5) graphics hard-copy may be produced site-wide on various dot-matrix printers; and (6) the system may provide integrated engineering services at both the engineering and engineering management level.

  16. Theodolite-camera videometrics system based on total station

    NASA Astrophysics Data System (ADS)

    Zhu, Zhao-kun; Yuan, Yun; Zhang, Xiao-hu

    2011-08-01

    A novel measuring system, named Theodolite-camera Videometrics System (TVS) based on total station, has been introduced in this paper, and the concept of theodolite-camera which is the key component of TVS has been proposed, it consists of non-metric camera and rotation platform generally, and can rotate horizontally and vertically. TVS based on total station is free of field control points, and the fields of view of its theodolite-cameras are nonfixed, thus TVS is qualified for targets with wide moving range or big structure. Theodolite-camera model has been analyzed and presented in detail in this paper. The calibration strategy adopted has been demonstrated to be accurate and feasible by both simulated and real data, and TVS has also been proved to be a valid, reliable, precise measuring system, and living up to expectations.

  17. GSM base station electromagnetic radiation and oxidative stress in rats.

    PubMed

    Yurekli, Ali Ihsan; Ozkan, Mehmed; Kalkan, Tunaya; Saybasili, Hale; Tuncel, Handan; Atukeren, Pinar; Gumustas, Koray; Seker, Selim

    2006-01-01

    The ever increasing use of cellular phones and the increasing number of associated base stations are becoming a widespread source of nonionizing electromagnetic radiation. Some biological effects are likely to occur even at low-level EM fields. In this study, a gigahertz transverse electromagnetic (GTEM) cell was used as an exposure environment for plane wave conditions of far-field free space EM field propagation at the GSM base transceiver station (BTS) frequency of 945 MHz, and effects on oxidative stress in rats were investigated. When EM fields at a power density of 3.67 W/m2 (specific absorption rate = 11.3 mW/kg), which is well below current exposure limits, were applied, MDA (malondialdehyde) level was found to increase and GSH (reduced glutathione) concentration was found to decrease significantly (p < 0.0001). Additionally, there was a less significant (p = 0.0190) increase in SOD (superoxide dismutase) activity under EM exposure.

  18. Programmable Ultra-Lightweight System Adaptable Radio Satellite Base Station

    NASA Technical Reports Server (NTRS)

    Varnavas, Kosta; Sims, Herb

    2015-01-01

    With the explosion of the CubeSat, small sat, and nanosat markets, the need for a robust, highly capable, yet affordable satellite base station, capable of telemetry capture and relay, is significant. The Programmable Ultra-Lightweight System Adaptable Radio (PULSAR) is NASA Marshall Space Flight Center's (MSFC's) software-defined digital radio, developed with previous Technology Investment Programs and Technology Transfer Office resources. The current PULSAR will have achieved a Technology Readiness Level-6 by the end of FY 2014. The extensibility of the PULSAR will allow it to be adapted to perform the tasks of a mobile base station capable of commanding, receiving, and processing satellite, rover, or planetary probe data streams with an appropriate antenna.

  19. Evolving technologies for Space Station Freedom computer-based workstations

    NASA Technical Reports Server (NTRS)

    Jensen, Dean G.; Rudisill, Marianne

    1990-01-01

    Viewgraphs on evolving technologies for Space Station Freedom computer-based workstations are presented. The human-computer computer software environment modules are described. The following topics are addressed: command and control workstation concept; cupola workstation concept; Japanese experiment module RMS workstation concept; remote devices controlled from workstations; orbital maneuvering vehicle free flyer; remote manipulator system; Japanese experiment module exposed facility; Japanese experiment module small fine arm; flight telerobotic servicer; human-computer interaction; and workstation/robotics related activities.

  20. 78 FR 6344 - Certain Wireless Communications Base Stations and Components Thereof Notice of Receipt of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-30

    ... COMMISSION Certain Wireless Communications Base Stations and Components Thereof Notice of Receipt of... received a complaint entitled Certain Wireless Communications Base Stations and Components Thereof, DN 2934... the sale within the United States after importation of certain wireless communications base...

  1. Research of a synchronized cooperative GIS system based on message

    NASA Astrophysics Data System (ADS)

    Sun, Yaqin; Du, Peijun; Zhou, Liangchen

    2010-11-01

    In traditional electronic government GIS (E-gov GIS), spatial data evaluation, examination and approval are dealt with by individuals, and the results are shared among collaborators in asynchronous mode. In order to improve the collaborative ability of E-gov GIS, a message-based synchronized cooperative GIS system (MSCGIS) is proposed in this paper. MSCGIS abstracts collaborators' GIS operations and encapsulates them into GIS command messages. And then the GIS command messages are passed and executed among related collaborators. Based on messaging, MSCGIS can realize the GIS synchronized cooperation of group. Some key issues are investigated in detail, such as the design scheme of MSCGIS, the encoding specification of GIS command message based on XML, and the interface and the collaborative process of prototype system. In a word, the construction idea of MSCGIS is sharing the GIS functions through passing collaborators' operations, rather than sharing spatial data among collaborators in traditional modes.

  2. Research of a synchronized cooperative GIS system based on message

    NASA Astrophysics Data System (ADS)

    Sun, Yaqin; Du, Peijun; Zhou, Liangchen

    2009-09-01

    In traditional electronic government GIS (E-gov GIS), spatial data evaluation, examination and approval are dealt with by individuals, and the results are shared among collaborators in asynchronous mode. In order to improve the collaborative ability of E-gov GIS, a message-based synchronized cooperative GIS system (MSCGIS) is proposed in this paper. MSCGIS abstracts collaborators' GIS operations and encapsulates them into GIS command messages. And then the GIS command messages are passed and executed among related collaborators. Based on messaging, MSCGIS can realize the GIS synchronized cooperation of group. Some key issues are investigated in detail, such as the design scheme of MSCGIS, the encoding specification of GIS command message based on XML, and the interface and the collaborative process of prototype system. In a word, the construction idea of MSCGIS is sharing the GIS functions through passing collaborators' operations, rather than sharing spatial data among collaborators in traditional modes.

  3. The Earth Based Ground Stations Element of the Lunar Program

    NASA Technical Reports Server (NTRS)

    Gal-Edd, Jonathan; Fatig, Curtis; Schier, James; Lee, Charles

    2007-01-01

    The Lunar Architecture Team (LAT) is responsible for developing a concept for building and supporting a lunar outpost with several exploration capabilities such as rovers, colonization, and observatories. The lunar outpost is planned to be located at the Moon's South Pole. The LAT Communications and Navigation Team (C&N) is responsible for defining the network infrastructure to support the lunar outpost. The following elements are needed to support lunar outpost activities: A Lunar surface network based on industry standard wireless 802.xx protocols, relay satellites positioned 180 degrees apart to provide South Pole coverage for the half of the lunar 28-day orbit that is obscured from Earth view, earth-based ground stations deployed at geographical locations 120 degrees apart. This paper will focus on the Earth ground stations of the lunar architecture. Two types of ground station networks are discussed. One provides Direct to Earth (DTE) support to lunar users using Kaband 23/26Giga-Hertz (GHz) communication frequencies. The second supports the Lunar Relay Satellite (LRS) that will be using Ka-band 40/37GHz (Q-band). This paper will discuss strategies to provide a robust operational network in support of various lunar missions and trades of building new antennas at non-NASA facilities, to improve coverage and provide site diversification for handling rain attenuation.

  4. A logical model of cooperating rule-based systems

    NASA Technical Reports Server (NTRS)

    Bailin, Sidney C.; Moore, John M.; Hilberg, Robert H.; Murphy, Elizabeth D.; Bahder, Shari A.

    1989-01-01

    A model is developed to assist in the planning, specification, development, and verification of space information systems involving distributed rule-based systems. The model is based on an analysis of possible uses of rule-based systems in control centers. This analysis is summarized as a data-flow model for a hypothetical intelligent control center. From this data-flow model, the logical model of cooperating rule-based systems is extracted. This model consists of four layers of increasing capability: (1) communicating agents, (2) belief-sharing knowledge sources, (3) goal-sharing interest areas, and (4) task-sharing job roles.

  5. Optimising base station location for UMTS cellular networks

    NASA Astrophysics Data System (ADS)

    Kalata, G.; Pozniak-Koszalka, I.; Koszalka, L.; Kasprzak, A.

    2014-12-01

    Rapid development of universal mobile telecommunication systems put demands on tools for assisting planning of cellular network infrastructure. The tools need to focus on critical issues in modern cellular networks and techniques used for previous generation system no longer serve useful. In this paper, an algorithm based on Branch & Bound approach is proposed for solving base station location problem, covering interference levels, traffic demands and power control mechanism. The efficiency of the algorithm is evaluated with respect to existing approaches for solving this problem - using the designed and implemented experimentation system.

  6. Image feature extraction based multiple ant colonies cooperation

    NASA Astrophysics Data System (ADS)

    Zhang, Zhilong; Yang, Weiping; Li, Jicheng

    2015-05-01

    This paper presents a novel image feature extraction algorithm based on multiple ant colonies cooperation. Firstly, a low resolution version of the input image is created using Gaussian pyramid algorithm, and two ant colonies are spread on the source image and low resolution image respectively. The ant colony on the low resolution image uses phase congruency as its inspiration information, while the ant colony on the source image uses gradient magnitude as its inspiration information. These two ant colonies cooperate to extract salient image features through sharing a same pheromone matrix. After the optimization process, image features are detected based on thresholding the pheromone matrix. Since gradient magnitude and phase congruency of the input image are used as inspiration information of the ant colonies, our algorithm shows higher intelligence and is capable of acquiring more complete and meaningful image features than other simpler edge detectors.

  7. Feature selection with neighborhood entropy-based cooperative game theory.

    PubMed

    Zeng, Kai; She, Kun; Niu, Xinzheng

    2014-01-01

    Feature selection plays an important role in machine learning and data mining. In recent years, various feature measurements have been proposed to select significant features from high-dimensional datasets. However, most traditional feature selection methods will ignore some features which have strong classification ability as a group but are weak as individuals. To deal with this problem, we redefine the redundancy, interdependence, and independence of features by using neighborhood entropy. Then the neighborhood entropy-based feature contribution is proposed under the framework of cooperative game. The evaluative criteria of features can be formalized as the product of contribution and other classical feature measures. Finally, the proposed method is tested on several UCI datasets. The results show that neighborhood entropy-based cooperative game theory model (NECGT) yield better performance than classical ones.

  8. Project-based learning in Geotechnics: cooperative versus collaborative teamwork

    NASA Astrophysics Data System (ADS)

    Pinho-Lopes, Margarida; Macedo, Joaquim

    2016-01-01

    Since 2007/2008 project-based learning models have been used to deliver two fundamental courses on Geotechnics in University of Aveiro, Portugal. These models have evolved and have encompassed either cooperative or collaborative teamwork. Using data collected in five editions of each course (Soil Mechanics I and Soil Mechanics II), the different characteristics of the models using cooperative or collaborative teamwork are pointed out and analysed, namely in terms of the students' perceptions. The data collected include informal feedback from students, monitoring of their marks and academic performance, and answers to two sets of questionnaires: developed for these courses, and institutional. The data indicate students have good opinion of the project-based learning model, though collaborative teamwork is the best rated. The overall efficacy of the models was analysed (sum of their effectiveness, efficiency and attractiveness). The collaborative model was found more adequate.

  9. Cooperative Opportunistic Pressure Based Routing for Underwater Wireless Sensor Networks

    PubMed Central

    Javaid, Nadeem; Muhammad; Sher, Arshad; Abdul, Wadood; Niaz, Iftikhar Azim; Almogren, Ahmad; Alamri, Atif

    2017-01-01

    In this paper, three opportunistic pressure based routing techniques for underwater wireless sensor networks (UWSNs) are proposed. The first one is the cooperative opportunistic pressure based routing protocol (Co-Hydrocast), second technique is the improved Hydrocast (improved-Hydrocast), and third one is the cooperative improved Hydrocast (Co-improved Hydrocast). In order to minimize lengthy routing paths between the source and the destination and to avoid void holes at the sparse networks, sensor nodes are deployed at different strategic locations. The deployment of sensor nodes at strategic locations assure the maximum monitoring of the network field. To conserve the energy consumption and minimize the number of hops, greedy algorithm is used to transmit data packets from the source to the destination. Moreover, the opportunistic routing is also exploited to avoid void regions by making backward transmissions to find reliable path towards the destination in the network. The relay cooperation mechanism is used for reliable data packet delivery, when signal to noise ratio (SNR) of the received signal is not within the predefined threshold then the maximal ratio combining (MRC) is used as a diversity technique to improve the SNR of the received signals at the destination. Extensive simulations validate that our schemes perform better in terms of packet delivery ratio and energy consumption than the existing technique; Hydrocast. PMID:28335494

  10. Cooperative Opportunistic Pressure Based Routing for Underwater Wireless Sensor Networks.

    PubMed

    Javaid, Nadeem; Muhammad; Sher, Arshad; Abdul, Wadood; Niaz, Iftikhar Azim; Almogren, Ahmad; Alamri, Atif

    2017-03-19

    In this paper, three opportunistic pressure based routing techniques for underwater wireless sensor networks (UWSNs) are proposed. The first one is the cooperative opportunistic pressure based routing protocol (Co-Hydrocast), second technique is the improved Hydrocast (improved-Hydrocast), and third one is the cooperative improved Hydrocast (Co-improved Hydrocast). In order to minimize lengthy routing paths between the source and the destination and to avoid void holes at the sparse networks, sensor nodes are deployed at different strategic locations. The deployment of sensor nodes at strategic locations assure the maximum monitoring of the network field. To conserve the energy consumption and minimize the number of hops, greedy algorithm is used to transmit data packets from the source to the destination. Moreover, the opportunistic routing is also exploited to avoid void regions by making backward transmissions to find reliable path towards the destination in the network. The relay cooperation mechanism is used for reliable data packet delivery, when signal to noise ratio (SNR) of the received signal is not within the predefined threshold then the maximal ratio combining (MRC) is used as a diversity technique to improve the SNR of the received signals at the destination. Extensive simulations validate that our schemes perform better in terms of packet delivery ratio and energy consumption than the existing technique; Hydrocast.

  11. Cooperative peer-to-peer multiagent-based systems

    NASA Astrophysics Data System (ADS)

    Caram, L. F.; Caiafa, C. F.; Ausloos, M.; Proto, A. N.

    2015-08-01

    A multiagent based model for a system of cooperative agents aiming at growth is proposed. This is based on a set of generalized Verhulst-Lotka-Volterra differential equations. In this study, strong cooperation is allowed among agents having similar sizes, and weak cooperation if agents have markedly different "sizes", thus establishing a peer-to-peer modulated interaction scheme. A rigorous analysis of the stable configurations is presented first examining the fixed points of the system, next determining their stability as a function of the model parameters. It is found that the agents are self-organizing into clusters. Furthermore, it is demonstrated that, depending on parameter values, multiple stable configurations can coexist. It occurs that only one of them always emerges with probability close to one, because its associated attractor dominates over the rest. This is shown through numerical integrations and simulations, after analytic developments. In contrast to the competitive case, agents are able to increase their capacity beyond the no-interaction case limit. In other words, when some collaborative partnership among a relatively small number of partners takes place, all agents act in good faith prioritizing the common good, when receiving a mutual benefit allowing them to surpass their capacity.

  12. Cooperative peer-to-peer multiagent-based systems.

    PubMed

    Caram, L F; Caiafa, C F; Ausloos, M; Proto, A N

    2015-08-01

    A multiagent based model for a system of cooperative agents aiming at growth is proposed. This is based on a set of generalized Verhulst-Lotka-Volterra differential equations. In this study, strong cooperation is allowed among agents having similar sizes, and weak cooperation if agents have markedly different "sizes", thus establishing a peer-to-peer modulated interaction scheme. A rigorous analysis of the stable configurations is presented first examining the fixed points of the system, next determining their stability as a function of the model parameters. It is found that the agents are self-organizing into clusters. Furthermore, it is demonstrated that, depending on parameter values, multiple stable configurations can coexist. It occurs that only one of them always emerges with probability close to one, because its associated attractor dominates over the rest. This is shown through numerical integrations and simulations, after analytic developments. In contrast to the competitive case, agents are able to increase their capacity beyond the no-interaction case limit. In other words, when some collaborative partnership among a relatively small number of partners takes place, all agents act in good faith prioritizing the common good, when receiving a mutual benefit allowing them to surpass their capacity.

  13. [Health care based on cooperation between professionals and affected people].

    PubMed

    Muriel-Fernández, Rafael; García-Domínguez, José-Miguel; Rodríguez-Gómez, Susana; Sagués-Amadó, Antonio

    2016-01-01

    The purpose of this article is to support the need for a change of care, based on cooperation between those who provide care and those who receive it. This article develops the decisive factors for change: the investee cooperation, the reference in case management, the concept of recovery and terminal care, the reduction of suffering and the value of change reflected in the 'win-win'. In each of them a questioning of the current situation, a methodological analysis and an input of tools and consequences of the change is made. To conclude, the article incorporates the 'itinerary of shared care' as a resource and one of the ways to bring these changes to the reality of day-to-day care. Copyright © 2015 Elsevier España, S.L.U. All rights reserved.

  14. Electromagnetic fields from mobile phone base station - variability analysis.

    PubMed

    Bienkowski, Pawel; Zubrzak, Bartlomiej

    2015-09-01

    The article describes the character of electromagnetic field (EMF) in mobile phone base station (BS) surroundings and its variability in time with an emphasis on the measurement difficulties related to its pulse and multi-frequency nature. Work also presents long-term monitoring measurements performed recently in different locations in Poland - small city with dispersed building development and in major polish city - dense urban area. Authors tried to determine the trends in changing of EMF spectrum analyzing daily changes of measured EMF levels in those locations. Research was performed using selective electromagnetic meters and also EMF meter with spectrum analysis.

  15. Integrated Attitude Control Based on Momentum Management for Space Station

    NASA Astrophysics Data System (ADS)

    Zhou, Li-Ni

    An integrated attitude control for attitude control, momentum management and power storage is proposed as a momentum-management-based IPACS. The integrated attitude control combines ACMM and IPACS to guarantees the momentum of CMGs and flywheels within acceptable limits as well as satisfying the requirements of attitude control and power storage. The later objective is to testify the foundation of the integrated attitude control by the fact that the momentum management of the integrated attitude control is able to keep the momentum exchange actuators including flywheels and VSCMG out of singularity. Finally, the space station attitude control task during assembly process is illustrated to testify the effectiveness of the integrated attitude control.

  16. Cooperativity-based modeling of heterotypic DNA nanostructure assembly

    PubMed Central

    Shapiro, Anastasia; Hozeh, Avital; Girshevitz, Olga; Abu-Horowitz, Almogit; Bachelet, Ido

    2015-01-01

    DNA origami is a robust method for the fabrication of nanoscale 2D and 3D objects with complex features and geometries. The process of DNA origami folding has been recently studied, however quantitative understanding of it is still elusive. Here, we describe a systematic quantification of the assembly process of DNA nanostructures, focusing on the heterotypic DNA junction—in which arms are unequal—as their basic building block. Using bulk fluorescence studies we tracked this process and identified multiple levels of cooperativity from the arms in a single junction to neighboring junctions in a large DNA origami object, demonstrating that cooperativity is a central underlying mechanism in the process of DNA nanostructure assembly. We show that the assembly of junctions in which the arms are consecutively ordered is more efficient than junctions with randomly-ordered components, with the latter showing assembly through several alternative trajectories as a potential mechanism explaining the lower efficiency. This highlights consecutiveness as a new design consideration that could be implemented in DNA nanotechnology CAD tools to produce more efficient and high-yield designs. Altogether, our experimental findings allowed us to devise a quantitative, cooperativity-based heuristic model for the assembly of DNA nanostructures, which is highly consistent with experimental observations. PMID:26071955

  17. Cooperativity-based modeling of heterotypic DNA nanostructure assembly.

    PubMed

    Shapiro, Anastasia; Hozeh, Avital; Girshevitz, Olga; Abu-Horowitz, Almogit; Bachelet, Ido

    2015-07-27

    DNA origami is a robust method for the fabrication of nanoscale 2D and 3D objects with complex features and geometries. The process of DNA origami folding has been recently studied, however quantitative understanding of it is still elusive. Here, we describe a systematic quantification of the assembly process of DNA nanostructures, focusing on the heterotypic DNA junction-in which arms are unequal-as their basic building block. Using bulk fluorescence studies we tracked this process and identified multiple levels of cooperativity from the arms in a single junction to neighboring junctions in a large DNA origami object, demonstrating that cooperativity is a central underlying mechanism in the process of DNA nanostructure assembly. We show that the assembly of junctions in which the arms are consecutively ordered is more efficient than junctions with randomly-ordered components, with the latter showing assembly through several alternative trajectories as a potential mechanism explaining the lower efficiency. This highlights consecutiveness as a new design consideration that could be implemented in DNA nanotechnology CAD tools to produce more efficient and high-yield designs. Altogether, our experimental findings allowed us to devise a quantitative, cooperativity-based heuristic model for the assembly of DNA nanostructures, which is highly consistent with experimental observations.

  18. Task-Based Flocking Algorithm for Mobile Robot Cooperation

    NASA Astrophysics Data System (ADS)

    He, Hongsheng; Ge, Shuzhi Sam; Tong, Guofeng

    In this paper, one task-based flocking algorithm that coordinates a swarm of robots is presented and evaluated based on the standard simulation platform. Task-based flocking algorithm(TFA) is an effective framework for mobile robots cooperation. Flocking behaviors are integrated into the cooperation of the multi-robot system to organize a robot team to achieve a common goal. The goal of the whole team is obtained through the collaboration of the individual robot’s task. The flocking model is presented, and the flocking energy function is defined based on that model to analyze the stability of the flocking and the task switching criterion. The simulation study is conducted in a five-versus-five soccer game, where the each robot dynamically selects its task in accordance with status and the whole robot team behaves as a flocking. Through simulation results and experiments, it is proved that the task-based flocking algorithm can effectively coordinate and control the robot flock to achieve the goal.

  19. Charging stations location model based on spatiotemporal electromobility use patterns

    NASA Astrophysics Data System (ADS)

    Pagany, Raphaela; Marquardt, Anna; Zink, Roland

    2016-04-01

    One of the major challenges for mainstream adoption of electric vehicles is the provision of infrastructure for charging the batteries of the vehicles. The charging stations must not only be located dense enough to allow users to complete their journeys, but the electric energy must also be provided from renewable sources in order to truly offer a transportation with less CO2 emissions. The examination of potential locations for the charging of electric vehicles can facilitate the adaption of electromobility and the integration of electronic vehicles in everyday life. A geographic information system (GIS) based model for optimal location of charging stations in a small and regional scale is presented. This considers parameters such as the forecast of electric vehicle use penetration, the relevant weight of diverse point of interests and the distance between parking area and destination for different vehicle users. In addition to the spatial scale the temporal modelling of the energy demand at the different charging locations has to be considerate. Depending on different user profiles (commuters, short haul drivers etc.) the frequency of charging vary during the day, the week and the year. In consequence, the spatiotemporal variability is a challenge for a reliable energy supply inside a decentralized renewable energy system. The presented model delivers on the one side the most adequate identified locations for charging stations and on the other side the interaction between energy supply and demand for electromobility under the consideration of temporal aspects. Using ESRI ArcGIS Desktop, first results for the case study region of Lower Bavaria are generated. The aim of the concept is to keep the model transferable to other regions and also open to integrate further and more detailed user profiles, derived from social studies about i.e. the daily behavior and the perception of electromobility in a next step.

  20. Knowledge-based assistance in costing the space station DMS

    NASA Technical Reports Server (NTRS)

    Henson, Troy; Rone, Kyle

    1988-01-01

    The Software Cost Engineering (SCE) methodology developed over the last two decades at IBM Systems Integration Division (SID) in Houston is utilized to cost the NASA Space Station Data Management System (DMS). An ongoing project to capture this methodology, which is built on a foundation of experiences and lessons learned, has resulted in the development of an internal-use-only, PC-based prototype that integrates algorithmic tools with knowledge-based decision support assistants. This prototype Software Cost Engineering Automation Tool (SCEAT) is being employed to assist in the DMS costing exercises. At the same time, DMS costing serves as a forcing function and provides a platform for the continuing, iterative development, calibration, and validation and verification of SCEAT. The data that forms the cost engineering database is derived from more than 15 years of development of NASA Space Shuttle software, ranging from low criticality, low complexity support tools to highly complex and highly critical onboard software.

  1. Development of automated microrobot-based nanohandling stations for nanocharacterization

    NASA Astrophysics Data System (ADS)

    Fatikow, Sergej; Eichhorn, Volkmar; Krohs, Florian; Mircea, Iulian; Stolle, Christian; Hagemann, Saskia

    2007-05-01

    Current research work on the development of automated microrobot-based nanohandling stations (AMNSs) using the probe of an atomic force microscope (AFM) as an endeffector is presented. The manipulation of individual multiwalled carbon nanotubes (MWCNTs) and the characterization of eukaryotic cells are aspired applications. For this reason, the developed AMNSs have to be integrated both into a scanning electron microscope (SEM) for the nanomanipulation of carbon nanotubes (CNTs) and into an optical microscope for the cell characterization. Such an AMNS combines different micro- and nanomanipulators, each offering three degrees of freedom (DoF), in order to perform the coarse and fine positioning between object and endeffector. Piezoresistive AFM probes are applied as an endeffector allowing to measure the acting forces and to realize a force feedback for the station's control system. First investigations have been carried out by bending of MWCNTs and calculating the Young's modulus of a MWCNT. Electrically conductive adhesives (ECAs) have been developed for the microelectronics industry, and their mechanical properties have to be determined. Therefore an AMNS for the mechanical characterization of thin ECA coatings by nanoindentation inside an SEM is presented as well, showing first experimental results.

  2. Station-based Surface Data Value-Added Product

    SciTech Connect

    Tang, Q.; Xie, S.

    2015-07-01

    This report describes the Atmospheric Radiation Measurement (ARM) Best Estimate (ARMBE) station-based surface data (ARMBESTNS) value-added product. It is a twin data product of the ARMBE 2-Dimensional gridded (ARMBE2DGRID) data set. Unlike the ARMBE2DGRID data set, ARMBESTNS data are reported at the original site locations and show the original information (except for the interpolation over time). Therefore, the users have the flexibility to process the data with the approach more suitable for their applications. This document provides information about the input data, quality control (QC) method, and output format of this data set. As much of the information is identical to that of the ARMBE2DGRID data, this document will emphasize more on the different aspects of these two data sets.

  3. Estimation of base station position using timing advance measurements

    NASA Astrophysics Data System (ADS)

    Raitoharju, Matti; Ali-Löytty, Simo; Wirola, Lauri

    2011-10-01

    Timing Advance is used in TDMA (Time Division Multiple Access) systems, such as GSM and LTE, to synchronize the mobile phone to the cellular BS (Base Station). Mobile phone positioning can use TA measurements if BS positions are known, but in many cases BS positions are not in the public domain. In this work we study how to use a set of TA measurements taken by mobile phones at known positions to estimate the position of a BS. This paper describes two methods -- GMF (Gaussian Mixture Filter) and PMF (Point Mass Filter) for estimation of the BS position. Positioning performance is evaluated using simulated and real measurements. In suburban field tests, TA measurements suffice to determine BS position with an error comparable to the TA granularity (550m). GMF computes BS position much faster than PMF and is only slightly less accurate.

  4. Cooperative Learning: Improving University Instruction by Basing Practice on Validated Theory

    ERIC Educational Resources Information Center

    Johnson, David W.; Johnson, Roger T.; Smith, Karl A.

    2014-01-01

    Cooperative learning is an example of how theory validated by research may be applied to instructional practice. The major theoretical base for cooperative learning is social interdependence theory. It provides clear definitions of cooperative, competitive, and individualistic learning. Hundreds of research studies have validated its basic…

  5. Cooperative Learning: Improving University Instruction by Basing Practice on Validated Theory

    ERIC Educational Resources Information Center

    Johnson, David W.; Johnson, Roger T.; Smith, Karl A.

    2014-01-01

    Cooperative learning is an example of how theory validated by research may be applied to instructional practice. The major theoretical base for cooperative learning is social interdependence theory. It provides clear definitions of cooperative, competitive, and individualistic learning. Hundreds of research studies have validated its basic…

  6. NASA space station automation: AI-based technology review. Executive summary

    NASA Technical Reports Server (NTRS)

    Firschein, O.; Georgeff, M. P.; Park, W.; Cheeseman, P. C.; Goldberg, J.; Neumann, P.; Kautz, W. H.; Levitt, K. N.; Rom, R. J.; Poggio, A. A.

    1985-01-01

    Research and Development projects in automation technology for the Space Station are described. Artificial Intelligence (AI) based technologies are planned to enhance crew safety through reduced need for EVA, increase crew productivity through the reduction of routine operations, increase space station autonomy, and augment space station capability through the use of teleoperation and robotics.

  7. Acceptorless dehydrogenation of small molecules through cooperative base metal catalysis

    PubMed Central

    West, Julian G.; Huang, David; Sorensen, Erik J.

    2015-01-01

    The dehydrogenation of unactivated alkanes is an important transformation both in industrial and biological systems. Recent efforts towards this reaction have revolved around high temperature, organometallic C–H activation by noble metal catalysts that produce alkenes and hydrogen gas as the sole products. Conversely, natural desaturase systems proceed through stepwise hydrogen atom transfer at physiological temperature; however, these transformations require a terminal oxidant. Here we show combining tetra-n-butylammonium decatungstate (TBADT) and cobaloxime pyridine chloride (COPC) can catalytically dehydrogenate unactivated alkanes and alcohols under near-UV irradiation at room temperature with hydrogen as the sole by-product. This noble metal-free process follows a nature-inspired pathway of high- and low-energy hydrogen atom abstractions. The hydrogen evolution ability of cobaloximes is leveraged to render the system catalytic, with cooperative turnover numbers up to 48 and yields up to 83%. Our results demonstrate how cooperative base metal catalysis can achieve transformations previously restricted to precious metal catalysts. PMID:26656087

  8. Measurements and Modelling of Base Station Power Consumption under Real Traffic Loads †

    PubMed Central

    Lorincz, Josip; Garma, Tonko; Petrovic, Goran

    2012-01-01

    Base stations represent the main contributor to the energy consumption of a mobile cellular network. Since traffic load in mobile networks significantly varies during a working or weekend day, it is important to quantify the influence of these variations on the base station power consumption. Therefore, this paper investigates changes in the instantaneous power consumption of GSM (Global System for Mobile Communications) and UMTS (Universal Mobile Telecommunications System) base stations according to their respective traffic load. The real data in terms of the power consumption and traffic load have been obtained from continuous measurements performed on a fully operated base station site. Measurements show the existence of a direct relationship between base station traffic load and power consumption. According to this relationship, we develop a linear power consumption model for base stations of both technologies. This paper also gives an overview of the most important concepts which are being proposed to make cellular networks more energy-efficient. PMID:22666026

  9. Measurements and modelling of base station power consumption under real traffic loads.

    PubMed

    Lorincz, Josip; Garma, Tonko; Petrovic, Goran

    2012-01-01

    Base stations represent the main contributor to the energy consumption of a mobile cellular network. Since traffic load in mobile networks significantly varies during a working or weekend day, it is important to quantify the influence of these variations on the base station power consumption. Therefore, this paper investigates changes in the instantaneous power consumption of GSM (Global System for Mobile Communications) and UMTS (Universal Mobile Telecommunications System) base stations according to their respective traffic load. The real data in terms of the power consumption and traffic load have been obtained from continuous measurements performed on a fully operated base station site. Measurements show the existence of a direct relationship between base station traffic load and power consumption. According to this relationship, we develop a linear power consumption model for base stations of both technologies. This paper also gives an overview of the most important concepts which are being proposed to make cellular networks more energy-efficient.

  10. Deep Space Habitat Configurations Based On International Space Station Systems

    NASA Technical Reports Server (NTRS)

    Smitherman, David; Russell, Tiffany; Baysinger, Mike; Capizzo, Pete; Fabisinski, Leo; Griffin, Brand; Hornsby, Linda; Maples,Dauphne; Miernik, Janie

    2012-01-01

    A Deep Space Habitat (DSH) is the crew habitation module designed for long duration missions. Although humans have lived in space for many years, there has never been a habitat beyond low-Earth-orbit. As part of the Advanced Exploration Systems (AES) Habitation Project, a study was conducted to develop weightless habitat configurations using systems based on International Space Station (ISS) designs. Two mission sizes are described for a 4-crew 60-day mission, and a 4-crew 500-day mission using standard Node, Lab, and Multi-Purpose Logistics Module (MPLM) sized elements, and ISS derived habitation systems. These durations were selected to explore the lower and upper bound for the exploration missions under consideration including a range of excursions within the Earth-Moon vicinity, near earth asteroids, and Mars orbit. Current methods for sizing the mass and volume for habitats are based on mathematical models that assume the construction of a new single volume habitat. In contrast to that approach, this study explored the use of ISS designs based on existing hardware where available and construction of new hardware based on ISS designs where appropriate. Findings included a very robust design that could be reused if the DSH were assembled and based at the ISS and a transportation system were provided for its return after each mission. Mass estimates were found to be higher than mathematical models due primarily to the use of multiple ISS modules instead of one new large module, but the maturity of the designs using flight qualified systems have potential for improved cost, schedule, and risk benefits.

  11. Deep Space Habitat Configurations Based on International Space Station Systems

    NASA Technical Reports Server (NTRS)

    Smitherman, David; Russell, Tiffany; Baysinger, Mike; Capizzo, Pete; Fabisinski, Leo; Griffin, Brand; Hornsby, Linda; Maples, Dauphne; Miernik, Janie

    2012-01-01

    A Deep Space Habitat (DSH) is the crew habitation module designed for long duration missions. Although humans have lived in space for many years, there has never been a habitat beyond low-Earth-orbit. As part of the Advanced Exploration Systems (AES) Habitation Project, a study was conducted to develop weightless habitat configurations using systems based on International Space Station (ISS) designs. Two mission sizes are described for a 4-crew 60-day mission, and a 4-crew 500-day mission using standard Node, Lab, and Multi-Purpose Logistics Module (MPLM) sized elements, and ISS derived habitation systems. These durations were selected to explore the lower and upper bound for the exploration missions under consideration including a range of excursions within the Earth-Moon vicinity, near earth asteroids, and Mars orbit. Current methods for sizing the mass and volume for habitats are based on mathematical models that assume the construction of a new single volume habitat. In contrast to that approach, this study explored the use of ISS designs based on existing hardware where available and construction of new hardware based on ISS designs where appropriate. Findings included a very robust design that could be reused if the DSH were assembled and based at the ISS and a transportation system were provided for its return after each mission. Mass estimates were found to be higher than mathematical models due primarily to the use of multiple ISS modules instead of one new large module, but the maturity of the designs using flight qualified systems have potential for improved cost, schedule, and risk benefits.

  12. Automatic ground-based station for vicarious calibration

    NASA Astrophysics Data System (ADS)

    Schmechtig, Catherine; Santer, Richard P.; Roger, Jean-Claude; Meygret, Aime

    1997-12-01

    Vicarious calibration generally requires field activities in order to characterize surface reflectances and atmosphere to unable use the prediction of the radiance at the satellite level. To limit human presence on the field, an automatic ground-based station was defined as well as the required protocol to achieve satellite vicarious calibration. The solar irradiance measurements are self calibrated using the Langley technique. The instrument was designed so that, firstly, the same gun measures both the solar irradiance and the radiance (sky or ground) and, secondly, that the field of view is constant over the spectral range. These two conditions offer an intercalibration opportunity between radiance and irradiance as well as the field of view is well defined. Experimental determination of the field of view is possible in UV region based on the Rayleigh scattering. We, then, describe how to derive the TOA signal from measurements. Two approaches have been developed according the energetic characteristics we want to estimate (reflectance or radiance). Preliminary results of a field campaign in June 1997 are reported.

  13. Cooperative Environment Scans Based on a Multi-Robot System

    PubMed Central

    Kwon, Ji-Wook

    2015-01-01

    This paper proposes a cooperative environment scan system (CESS) using multiple robots, where each robot has low-cost range finders and low processing power. To organize and maintain the CESS, a base robot monitors the positions of the child robots, controls them, and builds a map of the unknown environment, while the child robots with low performance range finders provide obstacle information. Even though each child robot provides approximated and limited information of the obstacles, CESS replaces the single LRF, which has a high cost, because much of the information is acquired and accumulated by a number of the child robots. Moreover, the proposed CESS extends the measurement boundaries and detects obstacles hidden behind others. To show the performance of the proposed system and compare this with the numerical models of the commercialized 2D and 3D laser scanners, simulation results are included. PMID:25789491

  14. Variographic analysis of public exposure to electromagnetic radiation due to cellular base stations.

    PubMed

    Lemaire, Thomas; Wiart, Joe; De Doncker, Philippe

    2016-10-05

    The spatial structure of the vertical component of the electric field emitted by base stations in the Brussels region (Belgium) is measured, and studied using the variogram. A relationship between the variogram shape and base station antenna density in each measurement area is found; the variogram range and sill level are shown to depend on cellular base stations' antenna density, following exponential laws. Bioelectromagnetics. © 2016 Wiley Periodicals, Inc.

  15. Spatial modes of cooperation based on bounded rationality

    NASA Astrophysics Data System (ADS)

    Pan, Qiuhui; Wang, Lingxiao; Shi, Rongrong; Wang, Huan; He, Mingfeng

    2014-12-01

    Social factors, such as public opinion, values, ethics, moral standards, could guide people’s behavior to some degree. In this paper, we introduce social orientation as a motivator factor into the Nowak model, and discuss the variation of cooperation proportion under the function of motivator factor and betrayal temptation. Results show that motivator factors can promote cooperation proportion, and there is a motivator factor threshold. And a jump point is present in the value, on each side of which cooperation proportion has a small change. Reduction of betrayal temptation can also promote cooperation proportion, and there is a betrayal temptation threshold. And the value is corresponding with a jump point. And cooperation proportion changes very little on each side of the value. In addition, when betrayal temptation and motivator factor both play a role in a system, there are always cooperators and defectors in coexistence.

  16. Partner choice promotes cooperation: the two faces of testing with agent-based models.

    PubMed

    Campennì, Marco; Schino, Gabriele

    2014-03-07

    Reciprocity is one of the most debated among the mechanisms that have been proposed to explain the evolution of cooperation. While a distinction can be made between two general processes that can underlie reciprocation (within-pair temporal relations between cooperative events, and partner choice based on benefits received), theoretical modelling has concentrated on the former, while the latter has been often neglected. We developed a set of agent-based models in which agents adopted a strategy of obligate cooperation and partner choice based on benefits received. Our models tested the ability of partner choice both to reproduce significant emergent features of cooperation in group living animals and to promote the evolution of cooperation. Populations formed by agents adopting a strategy of obligate cooperation and partner choice based on benefits received showed differentiated "social relationships" and a positive correlation between cooperation given and received, two common phenomena in animal cooperation. When selection across multiple generations was added to the model, agents adopting a strategy of partner choice based on benefits received outperformed selfish agents that did not cooperate. Our results suggest partner choice is a significant aspect of cooperation and provides a possible mechanism for its evolution.

  17. Coexistence of 3G repeaters with LTE base stations.

    PubMed

    Yeo, Woon-Young; Lee, Sang-Min; Hwang, Gyung-Ho; Kim, Jae-Hoon

    2013-01-01

    Repeaters have been an attractive solution for mobile operators to upgrade their wireless networks at low cost and to extend network coverage effectively. Since the first LTE commercial deployment in 2009, many mobile operators have launched LTE networks by upgrading their 3G and legacy networks. Because all 3G frequency bands are shared with the frequency bands for LTE deployment and 3G mobile operators have an enormous number of repeaters, reusing 3G repeaters in LTE networks is definitely a practical and cost-efficient solution. However, 3G repeaters usually do not support spatial multiplexing with multiple antennas, and thus it is difficult to reuse them directly in LTE networks. In order to support spatial multiplexing of LTE, the role of 3G repeaters should be replaced with small LTE base stations or MIMO-capable repeaters. In this paper, a repeater network is proposed to reuse 3G repeaters in LTE deployment while still supporting multilayer transmission of LTE. Interestingly, the proposed network has a higher cluster throughput than an LTE network with MIMO-capable repeaters.

  18. Coexistence of 3G Repeaters with LTE Base Stations

    PubMed Central

    Yeo, Woon-Young

    2013-01-01

    Repeaters have been an attractive solution for mobile operators to upgrade their wireless networks at low cost and to extend network coverage effectively. Since the first LTE commercial deployment in 2009, many mobile operators have launched LTE networks by upgrading their 3G and legacy networks. Because all 3G frequency bands are shared with the frequency bands for LTE deployment and 3G mobile operators have an enormous number of repeaters, reusing 3G repeaters in LTE networks is definitely a practical and cost-efficient solution. However, 3G repeaters usually do not support spatial multiplexing with multiple antennas, and thus it is difficult to reuse them directly in LTE networks. In order to support spatial multiplexing of LTE, the role of 3G repeaters should be replaced with small LTE base stations or MIMO-capable repeaters. In this paper, a repeater network is proposed to reuse 3G repeaters in LTE deployment while still supporting multilayer transmission of LTE. Interestingly, the proposed network has a higher cluster throughput than an LTE network with MIMO-capable repeaters. PMID:24459420

  19. Small Dosimeter based on Timepix device for International Space Station

    NASA Astrophysics Data System (ADS)

    Turecek, D.; Pinsky, L.; Jakubek, J.; Vykydal, Z.; Stoffle, N.; Pospisil, S.

    2011-12-01

    The radiation environment in space is different, more complex and more intense than on Earth. Conventional devices and detection methods used nowadays do not allow to discriminate single particle types and the energy of the single particles. The Timepix detector is a position sensitive pixelated detector developed at CERN in a frame of the Medipix collaboration that provides capability to visualize tracks and measure energy of single particles. This information can be used for sorting the particles into different categories. It is possible to distinguish light charged particles such as electrons or heavy charged particles such as ions. Moreover, the Linear Energy Transfer (LET) for charged particles can be determined. Each category is assigned a quality factor corresponding to the energy a particle would deposit in the human tissue. By summing the dose of all particles an estimate of the dose rate can be calculated. For space dosimetry purposes a miniature device with the Timepix detector and a custom made integrated USB based readout interface has been constructed. The entire device has dimensions of a USB flash memory stick. The whole compact device is connected to a control PC and is operated continuously. The PC runs a software that controls data acquisition, adjusts the acquisition time adaptively according to the particle rate, analyzes the particle tracks, evaluates the deposited energy and the LET and visualizes in a simple display the estimated dose rate. The performance of the device will be tested during a mission on International Space Station planned towards the beginning of year 2012.

  20. Component Data Base for Space Station Resistojet Auxiliary Propulsion

    NASA Technical Reports Server (NTRS)

    Bader, Clayton H.

    1988-01-01

    The resistojet was baselined for Space Station auxiliary propulsion because of its operational versatility, efficiency, and durability. This report was conceived as a guide to designers and planners of the Space Station auxiliary propulsion system. It is directed to the low thrust resistojet concept, though it should have application to other station concepts or systems such as the Environmental Control and Life Support System (ECLSS), Manufacturing and Technology Laboratory (MTL), and the Waste Fluid Management System (WFMS). The information will likely be quite useful in the same capacity for other non-Space Station systems including satellite, freeflyers, explorers, and maneuvering vehicles. The report is a catalog of the most useful information for the most significant feed system components and is organized for the greatest convenience of the user.

  1. Ohio's First Electrolysis-Based Hydrogen Fueling Station

    NASA Technical Reports Server (NTRS)

    Demattia, Brianne

    2014-01-01

    Presentation to the earth day coalition describing efforts with NASA GRC and Cleveland RTA on Ohio's hydrogen fueling station and bus demonstration. Project background and goals, challenges and successes, and current status.

  2. A Dynamic Programming Approach for Base Station Sleeping in Cellular Networks

    NASA Astrophysics Data System (ADS)

    Gong, Jie; Zhou, Sheng; Niu, Zhisheng

    The energy consumption of the information and communication technology (ICT) industry, which has become a serious problem, is mostly due to the network infrastructure rather than the mobile terminals. In this paper, we focus on reducing the energy consumption of base stations (BSs) by adjusting their working modes (active or sleep). Specifically, the objective is to minimize the energy consumption while satisfying quality of service (QoS, e.g., blocking probability) requirement and, at the same time, avoiding frequent mode switching to reduce signaling and delay overhead. The problem is modeled as a dynamic programming (DP) problem, which is NP-hard in general. Based on cooperation among neighboring BSs, a low-complexity algorithm is proposed to reduce the size of state space as well as that of action space. Simulations demonstrate that, with the proposed algorithm, the active BS pattern well meets the time variation and the non-uniform spatial distribution of system traffic. Moreover, the tradeoff between the energy saving from BS sleeping and the cost of switching is well balanced by the proposed scheme.

  3. A study of knowledge-based systems for the Space Station

    NASA Technical Reports Server (NTRS)

    Friedland, Peter; Swietek, Gregg; Bullock, Bruce

    1989-01-01

    A rapid turnaround study on the potential uses of knowledge-based systems for Space Station Freedom was conducted from October 1987 through January 1988. Participants included both NASA personnel and experienced industrial knowledge engineers. Major results of the study included five recommended systems for the Baseline Configuration of the Space Station, an analysis of sensor hooks and scars, and a proposed plan for evolutionary growth of knowledge-based systems on the Space Station.

  4. Mobile phones, mobile phone base stations and cancer: a review.

    PubMed

    Moulder, J E; Foster, K R; Erdreich, L S; McNamee, J P

    2005-03-01

    There have been reports in the media and claims in the courts that radiofrequency (RF) emissions from mobile phones are a cause of cancer, and there have been numerous public objections to the siting of mobile phone base antennas because of a fear of cancer. This review summarizes the current state of evidence concerning whether the RF energy used for wireless communication might be carcinogenic. Relevant studies were identified by searching MedLine with a combination of exposure and endpoint terms. This was supplemented by a review of the over 1700 citations assembled by the Institute of Electrical and Electronics Engineers (IEEE) International Committee on Electromagnetic Safety as part of their updating of the IEEE C95.1 RF energy safety guidelines. Where there were multiple studies, preference was given to recent reports, to positive reports of effects and to attempts to confirm such positive reports. Biophysical considerations indicate that there is little theoretical basis for anticipating that RF energy would have significant biological effects at the power levels used by modern mobile phones and their base station antennas. The epidemiological evidence for a causal association between cancer and RF energy is weak and limited. Animal studies have provided no consistent evidence that exposure to RF energy at non-thermal intensities causes or promotes cancer. Extensive in vitro studies have found no consistent evidence of genotoxic potential, but in vitro studies assessing the epigenetic potential of RF energy are limited. Overall, a weight-of-evidence evaluation shows that the current evidence for a causal association between cancer and exposure to RF energy is weak and unconvincing. However, the existing epidemiology is limited and the possibility of epigenetic effects has not been thoroughly evaluated, so that additional research in those areas will be required for a more thorough assessment of the possibility of a causal connection between cancer and the

  5. Role of delay-based reward in the spatial cooperation

    NASA Astrophysics Data System (ADS)

    Wang, Xu-Wen; Nie, Sen; Jiang, Luo-Luo; Wang, Bing-Hong; Chen, Shi-Ming

    2017-01-01

    Strategy selection in games, a typical decision making, usually brings noticeable reward for players which have discounted value if the delay appears. The discounted value is measure: earning sooner with a small reward or later with a delayed larger reward. Here, we investigate effects of delayed rewards on the cooperation in structured population. It is found that delayed reward supports the spreading of cooperation in square lattice, small-world and random networks. In particular, intermediate reward differences between delays impel the highest cooperation level. Interestingly, cooperative individuals with the same delay time steps form clusters to resist the invasion of defects, and cooperative individuals with lowest delay reward survive because they form the largest clusters in the lattice.

  6. NetCooperate: a network-based tool for inferring host-microbe and microbe-microbe cooperation.

    PubMed

    Levy, Roie; Carr, Rogan; Kreimer, Anat; Freilich, Shiri; Borenstein, Elhanan

    2015-05-17

    Host-microbe and microbe-microbe interactions are often governed by the complex exchange of metabolites. Such interactions play a key role in determining the way pathogenic and commensal species impact their host and in the assembly of complex microbial communities. Recently, several studies have demonstrated how such interactions are reflected in the organization of the metabolic networks of the interacting species, and introduced various graph theory-based methods to predict host-microbe and microbe-microbe interactions directly from network topology. Using these methods, such studies have revealed evolutionary and ecological processes that shape species interactions and community assembly, highlighting the potential of this reverse-ecology research paradigm. NetCooperate is a web-based tool and a software package for determining host-microbe and microbe-microbe cooperative potential. It specifically calculates two previously developed and validated metrics for species interaction: the Biosynthetic Support Score which quantifies the ability of a host species to supply the nutritional requirements of a parasitic or a commensal species, and the Metabolic Complementarity Index which quantifies the complementarity of a pair of microbial organisms' niches. NetCooperate takes as input a pair of metabolic networks, and returns the pairwise metrics as well as a list of potential syntrophic metabolic compounds. The Biosynthetic Support Score and Metabolic Complementarity Index provide insight into host-microbe and microbe-microbe metabolic interactions. NetCooperate determines these interaction indices from metabolic network topology, and can be used for small- or large-scale analyses. NetCooperate is provided as both a web-based tool and an open-source Python module; both are freely available online at http://elbo.gs.washington.edu/software_netcooperate.html.

  7. Optimal base station placement for wireless sensor networks with successive interference cancellation.

    PubMed

    Shi, Lei; Zhang, Jianjun; Shi, Yi; Ding, Xu; Wei, Zhenchun

    2015-01-14

    We consider the base station placement problem for wireless sensor networks with successive interference cancellation (SIC) to improve throughput. We build a mathematical model for SIC. Although this model cannot be solved directly, it enables us to identify a necessary condition for SIC on distances from sensor nodes to the base station. Based on this relationship, we propose to divide the feasible region of the base station into small pieces and choose a point within each piece for base station placement. The point with the largest throughput is identified as the solution. The complexity of this algorithm is polynomial. Simulation results show that this algorithm can achieve about 25% improvement compared with the case that the base station is placed at the center of the network coverage area when using SIC.

  8. Optimal Base Station Placement for Wireless Sensor Networks with Successive Interference Cancellation

    PubMed Central

    Shi, Lei; Zhang, Jianjun; Shi, Yi; Ding, Xu; Wei, Zhenchun

    2015-01-01

    We consider the base station placement problem for wireless sensor networks with successive interference cancellation (SIC) to improve throughput. We build a mathematical model for SIC. Although this model cannot be solved directly, it enables us to identify a necessary condition for SIC on distances from sensor nodes to the base station. Based on this relationship, we propose to divide the feasible region of the base station into small pieces and choose a point within each piece for base station placement. The point with the largest throughput is identified as the solution. The complexity of this algorithm is polynomial. Simulation results show that this algorithm can achieve about 25% improvement compared with the case that the base station is placed at the center of the network coverage area when using SIC. PMID:25594600

  9. A cooperative control algorithm for camera based observational systems.

    SciTech Connect

    Young, Joseph G.

    2012-01-01

    Over the last several years, there has been considerable growth in camera based observation systems for a variety of safety, scientific, and recreational applications. In order to improve the effectiveness of these systems, we frequently desire the ability to increase the number of observed objects, but solving this problem is not as simple as adding more cameras. Quite often, there are economic or physical restrictions that prevent us from adding additional cameras to the system. As a result, we require methods that coordinate the tracking of objects between multiple cameras in an optimal way. In order to accomplish this goal, we present a new cooperative control algorithm for a camera based observational system. Specifically, we present a receding horizon control where we model the underlying optimal control problem as a mixed integer linear program. The benefit of this design is that we can coordinate the actions between each camera while simultaneously respecting its kinematics. In addition, we further improve the quality of our solution by coupling our algorithm with a Kalman filter. Through this integration, we not only add a predictive component to our control, but we use the uncertainty estimates provided by the filter to encourage the system to periodically observe any outliers in the observed area. This combined approach allows us to intelligently observe the entire region of interest in an effective and thorough manner.

  10. Friendship-based partner switching promotes cooperation in heterogeneous populations

    NASA Astrophysics Data System (ADS)

    Chen, Wei; Wu, Te; Li, Zhiwu; Wang, Long

    2016-02-01

    The forming of human social ties tends to be with similar individuals. This study concentrates on the emergence of cooperation among heterogeneous populations. A simple model is proposed by considering the impact of interplay between the evolution of strategies and that of social partnerships on cooperation dynamics. Whenever two individuals acquire the rewards by playing prisoner's dilemma game with each other, the friendship (friendship is quantified as the weight of a link) between the two individuals deepens. Individuals can switch off the social ties with the partners who are unfriendly and rewire to similar new ones. Under this partner switching mechanism, population structure is divided into several groups and cooperation can prevail. It is observed that the frequent tendency of partner switching can lead to the enhancement of cooperative behavior under the enormous temptation to defect. Moreover, the influence of discounting the relationship between different individuals is also investigated. Meanwhile, the cooperation prevails when the adjustment of friendships mainly depends on the incomes of selected individuals rather than that of their partners. Finally, it is found that too similar population fail to maximize the cooperation and there exists a moderate similarity that can optimize cooperation.

  11. 78 FR 13895 - Certain Wireless Communications Base Stations and Components Thereof; Institution of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-01

    ... COMMISSION Certain Wireless Communications Base Stations and Components Thereof; Institution of Investigation... wireless communications base stations and components thereof by reason of infringement of U.S. Patent No. 6..., the sale for importation, or the sale within the United States after importation of certain...

  12. Cooperation in aspiration-based N -person prisoner's dilemmas

    NASA Astrophysics Data System (ADS)

    Płatkowski, Tadeusz; Bujnowski, Paweł

    2009-03-01

    We propose a mathematical model of the N -person prisoner’s dilemma game played by a continuous population of agents with a time-dependent aspiration level. The model—a system of differential equations—takes into account the evolution of the aspiration level and of the mean frequency of the cooperators in the population. The dependence of the asymptotic level of cooperation on the individual payoffs and on the transition rates determining the agent’s reaction to the received payoffs is studied. In general the existence and the magnitude of the asymptotic level of cooperation depends on N , the payoffs and the transition rates, and decreases with increasing N .

  13. Dynamic cooperative clustering based power assignment: network capacity and lifetime efficient topology control in cooperative ad hoc networks.

    PubMed

    Li, Xiao-Hong; Xiao, Ling; Wang, Dong

    2014-01-01

    Cooperative communication (CC) is used in topology control as it can reduce the transmission power and expand the transmission range. However, all previous research on topology control under the CC model focused on maintaining network connectivity and minimizing the total energy consumption, which would lead to low network capacity, transmission interruption, or even network paralysis. Meanwhile, without considering the balance of energy consumption in the network, it would reduce the network lifetime and greatly affect the network performance. This paper tries to solve the above problems existing in the research on topology control under the CC model by proposing a power assignment (DCCPA) algorithm based on dynamic cooperative clustering in cooperative ad hoc networks. The new algorithm clusters the network to maximize network capacity and makes the clusters communicate with each other by CC. To reduce the number of redundant links between clusters, we design a static clustering method by using Kruskal algorithm. To maximize the network lifetime, we also propose a cluster head rotating method which can reach a good tradeoff between residual energy and distance for the cluster head reselection. Experimental results show that DCCPA can improve 80% network capacity with Cooperative Bridges algorithm; meanwhile, it can improve 20% network lifetime.

  14. Dynamic Cooperative Clustering Based Power Assignment: Network Capacity and Lifetime Efficient Topology Control in Cooperative Ad Hoc Networks

    PubMed Central

    Xiao, Ling

    2014-01-01

    Cooperative communication (CC) is used in topology control as it can reduce the transmission power and expand the transmission range. However, all previous research on topology control under the CC model focused on maintaining network connectivity and minimizing the total energy consumption, which would lead to low network capacity, transmission interruption, or even network paralysis. Meanwhile, without considering the balance of energy consumption in the network, it would reduce the network lifetime and greatly affect the network performance. This paper tries to solve the above problems existing in the research on topology control under the CC model by proposing a power assignment (DCCPA) algorithm based on dynamic cooperative clustering in cooperative ad hoc networks. The new algorithm clusters the network to maximize network capacity and makes the clusters communicate with each other by CC. To reduce the number of redundant links between clusters, we design a static clustering method by using Kruskal algorithm. To maximize the network lifetime, we also propose a cluster head rotating method which can reach a good tradeoff between residual energy and distance for the cluster head reselection. Experimental results show that DCCPA can improve 80% network capacity with Cooperative Bridges algorithm; meanwhile, it can improve 20% network lifetime. PMID:24757413

  15. Cooperative learning: a new application of problem-based learning in mental health training.

    PubMed

    Bahar-Ozvariş, Sevkat; Cetin, Füsun Cuhadaroğlu; Turan, Sevgi; Peters, Antoinette S

    2006-09-01

    Interaction in problem-based learning (PBL) tutorials is not necessarily cooperative, which may account for variation in learning outcomes. Therefore, a cooperative assessment structure was introduced in a PBL course and the difference examined between this method and individual, lecture-based learning in mental health training. Experimental student groups gained more knowledge between pre- and post-test than did control groups, and the experimental students who scored low on the pre-test made the greatest gains. Groups that reported greater cooperation tended to have higher achievement scores. Experimental students felt that cooperation helped them learn but it also took more time and was sometimes chaotic.

  16. Space Station nitrogen supply system based on stored chemicals

    NASA Technical Reports Server (NTRS)

    Powell, F. T.; Schwartz, M.

    1985-01-01

    The Space Station atmosphere is to have an 'earth-like' composition, and nitrogen is to be routinely supplied to replace losses. The required nitrogen is to be provided by an innovative method, involving a catalytic dissociation of liquid N2H4 and separation of the product nitrogen and hydrogen mixture. The considered technique of nitrogen storage and resupply has several advantages in comparison to methods using either cryogenic liquid or high pressure nitrogen. One advantage is related to savings with respect to launch weight, while a second advantage is provided by the obtained hydrogen which is available for other uses within the Space Station.

  17. Monitoring Method and Apparatus Using Asynchronous, One-Way Transmission from Sensor to Base Station

    NASA Technical Reports Server (NTRS)

    Jensen, Scott L. (Inventor); Drouant, George J. (Inventor)

    2013-01-01

    A monitoring system is disclosed, which includes a base station and at least one sensor unit that is separate from the base station. The at least one sensor unit resides in a dormant state until it is awakened by the triggering of a vibration-sensitive switch. Once awakened, the sensor may take a measurement, and then transmit to the base station the measurement. Once data is transmitted from the sensor to the base station, the sensor may return to its dormant state. There may be various sensors for each base station and the various sensors may optionally measure different quantities, such as current, voltage, single-axis and/or three-axis magnetic fields.

  18. Epidemiological evidence for a health risk from mobile phone base stations.

    PubMed

    Khurana, Vini G; Hardell, Lennart; Everaert, Joris; Bortkiewicz, Alicja; Carlberg, Michael; Ahonen, Mikko

    2010-01-01

    Human populations are increasingly exposed to microwave/radiofrequency (RF) emissions from wireless communication technology, including mobile phones and their base stations. By searching PubMed, we identified a total of 10 epidemiological studies that assessed for putative health effects of mobile phone base stations. Seven of these studies explored the association between base station proximity and neurobehavioral effects and three investigated cancer. We found that eight of the 10 studies reported increased prevalence of adverse neurobehavioral symptoms or cancer in populations living at distances < 500 meters from base stations. None of the studies reported exposure above accepted international guidelines, suggesting that current guidelines may be inadequate in protecting the health of human populations. We believe that comprehensive epidemiological studies of long-term mobile phone base station exposure are urgently required to more definitively understand its health impact.

  19. Outdoor field experience with autonomous RPC based stations

    NASA Astrophysics Data System (ADS)

    Lopes, L.; Assis, P.; Blanco, A.; Carolino, N.; Cerda, M. A.; Conceição, R.; Cunha, O.; Ferreira, M.; Fonte, P.; Luz, R.; Mendes, L.; Pereira, A.; Pimenta, M.; Sarmento, R.; Tomé, B.

    2016-09-01

    In the last two decades Resistive Plate Chambers were employed in the Cosmic Ray Experiments COVER-PLASTEX and ARGO/YBJ. In both experiments the detectors were housed indoors, likely owing to gas distribution requirements and the need to control environment variables that directly affect RPCs operational stability. But in experiments where Extended Air Shower (EAS) sampling is necessary, large area arrays composed by dispersed stations are deployed, rendering this kind of approach impossible. In this situation, it would be mandatory to have detectors that could be deployed in small standalone stations, with very rare opportunities for maintenance, and with good resilience to environmental conditions. Aiming to meet these requirements, we started some years ago the development of RPCs for Autonomous Stations. The results from indoor tests and measurements were very promising, both concerning performance and stability under very low gas flow rate, which is the main requirement for Autonomous Stations. In this work we update the indoor results and show the first ones concerning outdoor stable operation. In particular, a dynamic adjustment of the high voltage is applied to keep gas gain constant.

  20. Cooperators benefit through reputation-based partner choice in economic games.

    PubMed

    Sylwester, Karolina; Roberts, Gilbert

    2010-10-23

    Explaining unconditional cooperation, such as donations to charities or contributions to public goods, continues to present a problem. One possibility is that cooperation can pay through developing a reputation that makes one more likely to be chosen for a profitable cooperative partnership, a process termed competitive altruism (CA) or reputation-based partner choice. Here, we show, to our knowledge, for the first time, that investing in a cooperative reputation can bring net benefits through access to more cooperative partners. Participants played a public goods game (PGG) followed by an opportunity to select a partner for a second cooperative game. We found that those who gave more in the PGG were more often selected as desired partners and received more in the paired cooperative game. Reputational competition was even stronger when it was possible for participants to receive a higher payoff from partner choice. The benefits of being selected by a more cooperative partner outweighed the costs of cooperation in the reputation building phase. CA therefore provides an alternative to indirect reciprocity as an explanation for reputation-building behaviour. Furthermore, while indirect reciprocity depends upon individuals giving preference to those of good standing, CA can explain unconditional cooperation.

  1. Radiofrequency radiation injures trees around mobile phone base stations.

    PubMed

    Waldmann-Selsam, Cornelia; Balmori-de la Puente, Alfonso; Breunig, Helmut; Balmori, Alfonso

    2016-12-01

    In the last two decades, the deployment of phone masts around the world has taken place and, for many years, there has been a discussion in the scientific community about the possible environmental impact from mobile phone base stations. Trees have several advantages over animals as experimental subjects and the aim of this study was to verify whether there is a connection between unusual (generally unilateral) tree damage and radiofrequency exposure. To achieve this, a detailed long-term (2006-2015) field monitoring study was performed in the cities of Bamberg and Hallstadt (Germany). During monitoring, observations and photographic recordings of unusual or unexplainable tree damage were taken, alongside the measurement of electromagnetic radiation. In 2015 measurements of RF-EMF (Radiofrequency Electromagnetic Fields) were carried out. A polygon spanning both cities was chosen as the study site, where 144 measurements of the radiofrequency of electromagnetic fields were taken at a height of 1.5m in streets and parks at different locations. By interpolation of the 144 measurement points, we were able to compile an electromagnetic map of the power flux density in Bamberg and Hallstadt. We selected 60 damaged trees, in addition to 30 randomly selected trees and 30 trees in low radiation areas (n=120) in this polygon. The measurements of all trees revealed significant differences between the damaged side facing a phone mast and the opposite side, as well as differences between the exposed side of damaged trees and all other groups of trees in both sides. Thus, we found that side differences in measured values of power flux density corresponded to side differences in damage. The 30 selected trees in low radiation areas (no visual contact to any phone mast and power flux density under 50μW/m(2)) showed no damage. Statistical analysis demonstrated that electromagnetic radiation from mobile phone masts is harmful for trees. These results are consistent with the fact

  2. Application of Risk-Based Inspection method for gas compressor station

    NASA Astrophysics Data System (ADS)

    Zhang, Meng; Liang, Wei; Qiu, Zeyang; Lin, Yang

    2017-05-01

    According to the complex process and lots of equipment, there are risks in gas compressor station. At present, research on integrity management of gas compressor station is insufficient. In this paper, the basic principle of Risk Based Inspection (RBI) and the RBI methodology are studied; the process of RBI in the gas compressor station is developed. The corrosion loop and logistics loop of the gas compressor station are determined through the study of corrosion mechanism and process of the gas compressor station. The probability of failure is calculated by using the modified coefficient, and the consequence of failure is calculated by the quantitative method. In particular, we addressed the application of a RBI methodology in a gas compressor station. The risk ranking is helpful to find the best preventive plan for inspection in the case study.

  3. Space Station-based deep-space optical communication experiments

    NASA Technical Reports Server (NTRS)

    Chen, Chien-Chung; Schwartz, Jon A.

    1988-01-01

    A series of three experiments proposed for advanced optical deep-space communications is described. These proposed experiments would be carried out aboard the Space Station to test and evaluate the capability of optical instruments to conduct data communication and spacecraft navigation for deep-space missions. Techniques for effective data communication, precision spacecraft ranging, and accurate angular measurements will be developed and evaluated in a spaceborne environment.

  4. Public exposure to radio waves near GSM microcell and picocell base stations.

    PubMed

    Cooper, T G; Mann, S M; Khalid, M; Blackwell, R P

    2006-06-01

    Exposures of the general public to radio waves at locations near 20 randomly selected GSM microcell and picocell base stations in the UK have been assessed in the context of the International Commission on Non-Ionizing Radiation Protection (ICNIRP) guidelines. Compliance distances were calculated for the antennas of the base stations from their reported radiated powers. Under pessimistic assumptions that would maximise exposures, the minimum height at which the general public reference level could potentially be exceeded near any of the base station antennas was calculated to be 2.4 m above ground level. The power densities of the broadcast carriers transmitted by the base stations have been measured and scaled to include all other possible carriers. Exposures were generally in the range 0.002-2% of the ICNIRP general public reference level, and the greatest exposure quotient near any of the base stations was 8.6%. Exposures close to microcell base stations were found to be generally greater than those close to macrocell base stations.

  5. Competency-Based Cooperative Office Education. Vocational Education Curriculum Guide. Revision. Bulletin 1246.

    ERIC Educational Resources Information Center

    Louisiana State Dept. of Education, Baton Rouge. Div. of Vocational Education.

    This curriculum guide, dealing with competency-based cooperative office education in the State of Louisiana, consists of 10 chapters on program implementation and 12 instructional units. Covered in the first part of the guide are cooperative office education programs; coordination, program management, and student placement; legal responsibilities;…

  6. A Study on Family-School Cooperation Based on an Analysis of School Documentation

    ERIC Educational Resources Information Center

    Polovina, Nada; Stanisic, Jelena

    2007-01-01

    Family-school cooperation is a very complex process that can be studied at different levels in a number of different ways. This study has covered only some aspects of cooperation between parents and teachers, based on school documentation of a Belgrade elementary school. The study covered analyses of 60 Attendance Registers pertaining to 60…

  7. GNSS-based network positioning technology for cooperative emergency management

    NASA Astrophysics Data System (ADS)

    Wu, Caicong; Chu, Tianxing; Tang, Anning; Su, Huaihong

    2009-06-01

    Personal digital assistant (PDA) with built-in GPS chip begins to be used for city management and emergency response management nowadays. The intelligent terminal can be used for event recording, multimedia (photo, audio, and video) capturing, wireless communication, GPS positioning and navigation. In the near future, PDA would take place of the vehicle GPS monitoring terminal to provide more functions and convenient. This article organizes the PDA of the same team for emergency response event into an integrated network through wireless communication so that each terminal can see each other on the map, including the vehicle GPS monitoring terminals. All of the terminals should send its GPS position and collected information to the emergency response center (ERC) through GPRS with a customized protocol. Then the center would create the socket connection to push the neighbors' location and common or special information to the others in the team according to the terminal's requirement and its authorities, and the leader or commander could send commands and messages to all of the underling members also. The GNSS based positioning and communication network organizes the dispersive emergency response personnel handheld with PDA and vehicles equipped with vehicle GPS monitoring terminal into an organic and cooperative network, each member in the network can see where its colleagues are, so as to seek for the help or support and exchange information in real time without calling which avoids exposure to the tracked objects. The Compass-1 satellite positioning and communication terminal is also used for personnel and vehicle positioning and message reporting. Altay is selected as the demonstration area. The prototype emergency management system is established for the local public security bureau and well validates the terminals and network function.

  8. Reputation-based conditional interaction supports cooperation in well-mixed prisoner's dilemmas.

    PubMed

    Chen, Xiaojie; Schick, Alana; Doebeli, Michael; Blachford, Alistair; Wang, Long

    2012-01-01

    In the well-mixed prisoner's dilemma game, individuals are typically assumed to have no choice about whether to interact with other individuals in the population. In this paper, we instead consider reputation-based conditional interaction and its consequences for the evolution of cooperation. Each individual has a tolerance range, and only interacts with other individuals whose reputation lies within its tolerance range in a chosen sample of the population. Reputation contains information about the number of interaction partners an individual has just cooperated with. We find that the introduction of conditional interaction promotes cooperation in well-mixed populations, and there exist moderate tolerance ranges for which this effect is maximized. For a given tolerance range, there is a critical cost-to-benefit ratio below which cooperation can be promoted. Interestingly, we find that if cooperation evolves, different cooperators' interaction clusters are typically maintained in the population, each around a different reputation level. We further investigate some properties of these cooperators' clusters. Moreover, we examine the effects of the sample number on the evolution of cooperation. Our results highlight the importance of the detailed consideration of modes of interaction for the evolution of cooperation in well-mixed populations.

  9. Flywheel-Based Fast Charging Station – FFCS for Electric Vehicles and Public Transportation

    NASA Astrophysics Data System (ADS)

    Gabbar, Hossam A.; Othman, Ahmed M.

    2017-08-01

    This paper demonstrates novel Flywheel-based Fast Charging Station (FFCS) for high performance and profitable charging infrastructures for public electric buses. The design criteria will be provided for fast charging stations. The station would support the private and open charging framework. Flywheel Energy storage system is utilized to offer advanced energy storage for charging stations to achieve clean public transportation, including electric buses with reducing GHG, including CO2 emission reduction. The integrated modelling and management system in the station is performed by a decision-based control platform that coordinates the power streams between the quick chargers, the flywheel storage framework, photovoltaic cells and the network association. There is a tidy exchange up between the capacity rate of flywheel framework and the power rating of the network association.”

  10. The Training Information Management System. Volume 4. User’s Manual for the Training Base Station

    DTIC Science & Technology

    1986-07-01

    INFORMATION MANAGEMENT SYSTEM : User’s Manual for the Training Base Station Perceptroni cs N for ARI Field Unit...COVERED THE TRAINING INFORMATION MANAGEMENT SYSTEM : Final Report, Vol. 4 User’s Manual for the Training Base Station April B4 - January 86 5. PERFORMING ORG...ideuMIfy’ b7 block numbov) >The Training Information Management System (TIMS) is a computer-based system which can be used by Army personnel to collect

  11. Broadband Cooperative Spectrum Sensing Based on Distributed Modulated Wideband Converter.

    PubMed

    Xu, Ziyong; Li, Zhi; Li, Jian

    2016-09-28

    The modulated wideband converter (MWC) is a kind of sub-Nyquist sampling system which is developed from compressed sensing theory. It accomplishes highly accurate broadband sparse signal recovery by multichannel sub-Nyquist sampling sequences. However, when the number of sparse sub-bands becomes large, the amount of sampling channels increases proportionally. Besides, it is very hard to adjust the number of sampling channels when the sparsity changes, because its undersampling board is designed by a given sparsity. Such hardware cost and inconvenience are unacceptable in practical applications. This paper proposes a distributed modulated wideband converter (DMWC) scheme innovatively, which regards one sensor node as one sampling channel and combines MWC technology with a broadband cooperative spectrum sensing network perfectly. Being different from the MWC scheme, DMWC takes phase shift and transmission loss into account in the input terminal, which are unavoidable in practical application. Our scheme is not only able to recover the support of broadband sparse signals quickly and accurately, but also reduces the hardware cost of the single node drastically. Theoretical analysis and numerical simulations show that phase shift has no influence on the recovery of frequency support, but transmission loss degrades the recovery performance to a different extent. Nevertheless, we can increase the amount of cooperative nodes and select satisfactory nodes by a different transmission distance to improve the recovery performance. Furthermore, we can adjust the amount of cooperative nodes flexibly when the sparsity changes. It indicates DMWC is extremely effective in the broadband cooperative spectrum sensing network.

  12. Broadband Cooperative Spectrum Sensing Based on Distributed Modulated Wideband Converter

    PubMed Central

    Xu, Ziyong; Li, Zhi; Li, Jian

    2016-01-01

    The modulated wideband converter (MWC) is a kind of sub-Nyquist sampling system which is developed from compressed sensing theory. It accomplishes highly accurate broadband sparse signal recovery by multichannel sub-Nyquist sampling sequences. However, when the number of sparse sub-bands becomes large, the amount of sampling channels increases proportionally. Besides, it is very hard to adjust the number of sampling channels when the sparsity changes, because its undersampling board is designed by a given sparsity. Such hardware cost and inconvenience are unacceptable in practical applications. This paper proposes a distributed modulated wideband converter (DMWC) scheme innovatively, which regards one sensor node as one sampling channel and combines MWC technology with a broadband cooperative spectrum sensing network perfectly. Being different from the MWC scheme, DMWC takes phase shift and transmission loss into account in the input terminal, which are unavoidable in practical application. Our scheme is not only able to recover the support of broadband sparse signals quickly and accurately, but also reduces the hardware cost of the single node drastically. Theoretical analysis and numerical simulations show that phase shift has no influence on the recovery of frequency support, but transmission loss degrades the recovery performance to a different extent. Nevertheless, we can increase the amount of cooperative nodes and select satisfactory nodes by a different transmission distance to improve the recovery performance. Furthermore, we can adjust the amount of cooperative nodes flexibly when the sparsity changes. It indicates DMWC is extremely effective in the broadband cooperative spectrum sensing network. PMID:27690034

  13. Influence of Mobile Users' Density Distribution on the CDMA Base Station Power

    NASA Astrophysics Data System (ADS)

    Lebl, Aleksandar; Mitić, Dragan; Popović, Miroslav; Markov, Žarko; Mileusnić, Mladen; Matić, Vladimir

    2016-12-01

    In this paper we analyze the influence of users' density distribution in one cell of CDMA mobile network (ie adjusted power control on the forward link) on base station emission power. This influence is analyzed for different circles radii around base station within which same emission power is generated for all mobile users, and for different values of propagation loss coefficient. It is proved that emission power in this cell must be increased comparing to the similar cell, which uses complete power control. The power increase is greater when greater number of users are situated near base station, and for greater values of propagation loss coefficient. The results are presented, illustrated by numerical examples and verified by simulation for three users' density distributions: uniform, decreasing and increasing density from the base station to the cell rim. The simulation process, which is based on random traffic process, is presented briefly.

  14. Cooperation and Contagion in Web-Based, Networked Public Goods Experiments

    PubMed Central

    Suri, Siddharth; Watts, Duncan J.

    2011-01-01

    A longstanding idea in the literature on human cooperation is that cooperation should be reinforced when conditional cooperators are more likely to interact. In the context of social networks, this idea implies that cooperation should fare better in highly clustered networks such as cliques than in networks with low clustering such as random networks. To test this hypothesis, we conducted a series of web-based experiments, in which 24 individuals played a local public goods game arranged on one of five network topologies that varied between disconnected cliques and a random regular graph. In contrast with previous theoretical work, we found that network topology had no significant effect on average contributions. This result implies either that individuals are not conditional cooperators, or else that cooperation does not benefit from positive reinforcement between connected neighbors. We then tested both of these possibilities in two subsequent series of experiments in which artificial seed players were introduced, making either full or zero contributions. First, we found that although players did generally behave like conditional cooperators, they were as likely to decrease their contributions in response to low contributing neighbors as they were to increase their contributions in response to high contributing neighbors. Second, we found that positive effects of cooperation were contagious only to direct neighbors in the network. In total we report on 113 human subjects experiments, highlighting the speed, flexibility, and cost-effectiveness of web-based experiments over those conducted in physical labs. PMID:21412431

  15. Cooperation and contagion in web-based, networked public goods experiments.

    PubMed

    Suri, Siddharth; Watts, Duncan J

    2011-03-11

    A longstanding idea in the literature on human cooperation is that cooperation should be reinforced when conditional cooperators are more likely to interact. In the context of social networks, this idea implies that cooperation should fare better in highly clustered networks such as cliques than in networks with low clustering such as random networks. To test this hypothesis, we conducted a series of web-based experiments, in which 24 individuals played a local public goods game arranged on one of five network topologies that varied between disconnected cliques and a random regular graph. In contrast with previous theoretical work, we found that network topology had no significant effect on average contributions. This result implies either that individuals are not conditional cooperators, or else that cooperation does not benefit from positive reinforcement between connected neighbors. We then tested both of these possibilities in two subsequent series of experiments in which artificial seed players were introduced, making either full or zero contributions. First, we found that although players did generally behave like conditional cooperators, they were as likely to decrease their contributions in response to low contributing neighbors as they were to increase their contributions in response to high contributing neighbors. Second, we found that positive effects of cooperation were contagious only to direct neighbors in the network. In total we report on 113 human subjects experiments, highlighting the speed, flexibility, and cost-effectiveness of web-based experiments over those conducted in physical labs.

  16. Survey of RF exposure levels from mobile telephone base stations in Australia.

    PubMed

    Henderson, S I; Bangay, M J

    2006-01-01

    This paper reports the results of an exposure level survey of radiofrequency electromagnetic energy originating from mobile telephone base station antennas. Measurements of CDMA800, GSM900, GSM1800, and 3G(UMTS) signals were performed at distances ranging over 50 to 500 m from 60 base stations in five Australian cities. The exposure levels from these mobile telecommunications base stations were found to be well below the general public exposure limits of the ICNIRP guidelines and the Australian radiofrequency standard (ARPANSA RPS3). The highest recorded level from a single base station was 7.8 x 10(-3) W/m(2), which translates to 0.2% of the general public exposure limit.

  17. Lunar base mission technology issues and orbital demonstration requirements on space station

    NASA Technical Reports Server (NTRS)

    Llewellyn, Charles P.; Weidman, Deene J.

    1992-01-01

    The International Space Station has been the object of considerable design, redesign, and alteration since it was originally proposed in early 1984. In the intervening years the station has slowly evolved to a specific design that was thoroughly reviewed by a large agency-wide Critical Evaluation Task Force (CETF). As space station designs continue to evolve, studies must be conducted to determine the suitability of the current design for some of the primary purposes for which the station will be used. This paper concentrates on the technology requirements and issues, the on-orbit demonstration and verification program, and the space station focused support required prior to the establishment of a permanently manned lunar base as identified in the National Commission on Space report. Technology issues associated with the on-orbit assembly and processing of the lunar vehicle flight elements are also discussed.

  18. NIRS-Based Hyperscanning Reveals Increased Interpersonal Coherence in Superior Frontal Cortex during Cooperation

    PubMed Central

    Cui, Xu; Bryant, Daniel M.; Reiss, Allan L.

    2011-01-01

    We used Near-Infrared Spectroscopy (NIRS) to simultaneously measure brain activity in two people while they played a computer-based cooperation game side by side. Inter-brain activity coherence was calculated between the two participants. We found that the coherence between signals generated by participants right superior frontal cortices increased during cooperation, but not during competition. Increased coherence was also associated with better cooperation performance. To our knowledge, this work represents the first use of a single NIRS instrument for simultaneous measurements of brain activity in two people. This study demonstrates the use of NIRS-based hyperscanning in studies of social interaction in a naturalistic environment. PMID:21933717

  19. Graph-Based Cooperative Localization Using Symmetric Measurement Equations

    PubMed Central

    Gulati, Dhiraj; Zhang, Feihu; Clarke, Daniel; Knoll, Alois

    2017-01-01

    Precise localization is a key requirement for the success of highly assisted or autonomous vehicles. The diminishing cost of hardware has resulted in a proliferation of the number of sensors in the environment. Cooperative localization (CL) presents itself as a feasible and effective solution for localizing the ego-vehicle and its neighboring vehicles. However, one of the major challenges to fully realize the effective use of infrastructure sensors for jointly estimating the state of a vehicle in cooperative vehicle-infrastructure localization is an effective data association. In this paper, we propose a method which implements symmetric measurement equations within factor graphs in order to overcome the data association challenge with a reduced bandwidth overhead. Simulated results demonstrate the benefits of the proposed approach in comparison with our previously proposed approach of topology factors. PMID:28629141

  20. Graph-Based Cooperative Localization Using Symmetric Measurement Equations.

    PubMed

    Gulati, Dhiraj; Zhang, Feihu; Clarke, Daniel; Knoll, Alois

    2017-06-17

    Precise localization is a key requirement for the success of highly assisted or autonomous vehicles. The diminishing cost of hardware has resulted in a proliferation of the number of sensors in the environment. Cooperative localization (CL) presents itself as a feasible and effective solution for localizing the ego-vehicle and its neighboring vehicles. However, one of the major challenges to fully realize the effective use of infrastructure sensors for jointly estimating the state of a vehicle in cooperative vehicle-infrastructure localization is an effective data association. In this paper, we propose a method which implements symmetric measurement equations within factor graphs in order to overcome the data association challenge with a reduced bandwidth overhead. Simulated results demonstrate the benefits of the proposed approach in comparison with our previously proposed approach of topology factors.

  1. [Level of microwave radiation from mobile phone base stations built in residential districts].

    PubMed

    Hu, Ji; Lu, Yiyang; Zhang, Huacheng; Xie, Hebing; Yang, Xinwen

    2009-11-01

    To investigate the condition of microwave radiation pollution from mobile phone base station built in populated area. Random selected 18 residential districts where had base station and 10 residential districts where had no base stations. A TES-92 electromagnetic radiation monitor were used to measure the intensity of microwave radiation in external and internal living environment. The intensities of microwave radiation in the exposure residential districts were more higher than those of the control residential districts (p < 0.05). There was a intensity peak at about 10 m from the station, it would gradually weaken with the increase of the distance. The level of microwave radiation in antenna main lobe region is not certainly more higher than the side lobe direction, and the side lobe direction also is not more lower. At the same district, where there were two base stations, the electromagnetic field nestification would take place in someplace. The intensities of microwave radiation outside the exposure windows in the resident room not only changed with distance but also with the height of the floor. The intensities of microwave radiation inside the aluminum alloys security net were more lower than those of outside the aluminum alloys security net (p < 0.05), but the inside or outside of glass-window appears almost no change (p > 0.05). Although all the measure dates on the ground around the base station could be below the primary standard in "environment electromagnetic wave hygienic standard" (GB9175-88), there were still a minorities of windows which exposed to the base station were higher, and the outside or inside of a few window was even higher beyond the primary safe level defined standard. The aluminum alloys security net can partly shield the microwave radiation from the mobile phone base station.

  2. Dynamic analysis of the Space Station truss structure based on a continuum representation

    NASA Technical Reports Server (NTRS)

    Thomas, Segun; Stubbs, Norris

    1989-01-01

    A mathematical model is developed for the real-time simulation of a Space Station. First, a continuum equivalent representation of the Space Station truss structure is presented which accounts for extensional, transverse, and shear deformations and coupling between them. The procedure achieves a significant reduction in the degrees of freedom of the system. Dynamic equations are then formulated for the continuum equivalent of the Space Station truss structure based on the matrix version of Kane's dynamical equations. Finally, constraint equations are derived for the dynamic analysis of flexible bodies with closed loop configuration.

  3. Bus transport network of Shenyang considering competitive and cooperative relationship

    NASA Astrophysics Data System (ADS)

    Hu, Baoyu; Feng, Shumin; Nie, Cen

    2017-01-01

    Competition and cooperation is a universal phenomenon in bus transport networks (BTNs) because of the shared stations between bus routes. A measuring method is proposed for competitive and cooperative relationship between bus routes. Based on this measurement, we develop a new representation model for BTNs, namely competitive-cooperative space R. This model is applied to investigate empirically bus transport network of Shenyang (BTN-S) from China. We present the histograms of competitive-cooperative coefficients, competitive coefficients and cooperative coefficients to illustrate that competitive and cooperative relationship plays an important role in transporting passengers. The competitive-cooperative situation shows that cooperative relationship holds an absolutely dominant position in BTN-S. To explore the networked characteristics, we present some empirical distributions, for the number of bus stations on a route, the number of shared stations between two routes, degree and weighted degree, competitive strength, and cooperative strength. We also examine the correlations between degree and competitive strength, and between degree and cooperative strength. Besides, we investigate the diversities of competitive strength and cooperative strength in BTN-S. This study can help us to understand the BTN from a deeper level.

  4. Teaching calculus using module based on cooperative learning strategy

    NASA Astrophysics Data System (ADS)

    Arbin, Norazman; Ghani, Sazelli Abdul; Hamzah, Firdaus Mohamad

    2014-06-01

    The purpose of the research is to evaluate the effectiveness of a module which utilizes the cooperative learning for teaching Calculus for limit, derivative and integral. The sample consists of 50 semester 1 students from the Science Programme (AT 16) Sultan Idris Education University. A set of questions of related topics (pre and post) has been used as an instrument to collect data. The data is analyzed using inferential statistics involving the paired sample t-test and the independent t-test. The result shows that students have positive inclination towards the modulein terms of understanding.

  5. Prospective multicenter study of ultrasound-based measurements of fetal head station and position throughout labor.

    PubMed

    Vitner, D; Paltieli, Y; Haberman, S; Gonen, R; Ville, Y; Nizard, J

    2015-11-01

    To assess the relationship between fetal head position and head station during labor, as measured using an ultrasound-based system, and the occurrence of occiput posterior (OP) position at delivery. This was an international prospective observational study including women who delivered between January 2009 and September 2013 in four centers: one in Brooklyn, NY, USA; one in Haifa, Israel; and two in Paris, France. We used an ultrasound-based system (LaborPro) to monitor fetal head station and position non-invasively throughout labor. We collected data on demographics, labor parameters and outcome. A total of 595 women were included. In 563 (94.6%) women, fetal head position at delivery was occiput anterior (OA), in 31 (5.2%) it was OP and in one (0.2%) it was occiput transverse. In 89% of pregnancies with intrapartum OP when fetal head station was above -2, the head position turned to OA at delivery; the equivalent figures were 74% and 63% OA at delivery when intrapartum OP was diagnosed at head stations of -2 to < 0, and 0 and below, respectively. Cesarean delivery was performed in 35% of pregnancies with fetal head in OP position at delivery, as opposed to 10% of those with non-OP position at delivery. On retrospective analysis, all deliveries in OP were already in OP at station -2 and below. In this first assessment of fetal head position at delivery according to fetal head position at various station levels, our data show that 100% of OP positions at delivery were already in OP position at station -2 and below. We did not observe rotation from a non-OP to an OP position from station -2 and below. Nearly two-thirds of fetuses in OP at station 0 and below will rotate to an OA position for delivery. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

  6. International Cooperation for Space-Based Global Maritime Awareness- The Next Step

    NASA Astrophysics Data System (ADS)

    Greidanus, H.; Thomas, G. G.; Campbell, G.; Bryan, K.

    2013-03-01

    This paper aims to put forward for discussion a number of possible ways to promote international cooperation for global maritime awareness, in particular using space-based assets. Maritime awareness concerns the knowledge of human activities going on at sea, so for a large part equates to ship traffic detection and monitoring for safety, security and protection of resources and the environment. The essential benefits and challenges for cooperation, and related sharing of information, are recounted. Several concrete options for global cooperation that should be viable also in view of the challenges are proposed. A public discussion with global stakeholders should follow, leading to convergence on a mechanism that should be subsequently implemented.

  7. On Deployment of Multiple Base Stations for Energy-Efficient Communication in Wireless Sensor Networks

    DOE PAGES

    Lin, Yunyue; Wu, Qishi; Cai, Xiaoshan; ...

    2010-01-01

    Data transmission from sensor nodes to a base station or a sink node often incurs significant energy consumption, which critically affects network lifetime. We generalize and solve the problem of deploying multiple base stations to maximize network lifetime in terms of two different metrics under one-hop and multihop communication models. In the one-hop communication model, the sensors far away from base stations always deplete their energy much faster than others. We propose an optimal solution and a heuristic approach based on the minimal enclosing circle algorithm to deploy a base station at the geometric center of each cluster. In themore » multihop communication model, both base station location and data routing mechanism need to be considered in maximizing network lifetime. We propose an iterative algorithm based on rigorous mathematical derivations and use linear programming to compute the optimal routing paths for data transmission. Simulation results show the distinguished performance of the proposed deployment algorithms in maximizing network lifetime.« less

  8. Mobile phone base stations and well-being--A meta-analysis.

    PubMed

    Klaps, Armin; Ponocny, Ivo; Winker, Robert; Kundi, Michael; Auersperg, Felicitas; Barth, Alfred

    2016-02-15

    It is unclear whether electromagnetic fields emitted by mobile phone base stations affect well-being in adults. The existing studies on this topic are highly inconsistent. In the current paper we attempt to clarify this question by carrying out a meta-analysis which is based on the results of 17 studies. Double-blind studies found no effects on human well-being. By contrast, field or unblinded studies clearly showed that there were indeed effects. This provides evidence that at least some effects are based on a nocebo effect. Whether there is an influence of electromagnetic fields emitted by mobile phone base stations thus depends on a person's knowledge about the presence of the presumed cause. Taken together, the results of the meta-analysis show that the effects of mobile phone base stations seem to be rather unlikely. However, nocebo effects occur. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Reputation-Based Conditional Interaction Supports Cooperation in Well-Mixed Prisoner’s Dilemmas

    PubMed Central

    Chen, Xiaojie; Schick, Alana; Doebeli, Michael; Blachford, Alistair; Wang, Long

    2012-01-01

    In the well-mixed prisoner’s dilemma game, individuals are typically assumed to have no choice about whether to interact with other individuals in the population. In this paper, we instead consider reputation-based conditional interaction and its consequences for the evolution of cooperation. Each individual has a tolerance range, and only interacts with other individuals whose reputation lies within its tolerance range in a chosen sample of the population. Reputation contains information about the number of interaction partners an individual has just cooperated with. We find that the introduction of conditional interaction promotes cooperation in well-mixed populations, and there exist moderate tolerance ranges for which this effect is maximized. For a given tolerance range, there is a critical cost-to-benefit ratio below which cooperation can be promoted. Interestingly, we find that if cooperation evolves, different cooperators’ interaction clusters are typically maintained in the population, each around a different reputation level. We further investigate some properties of these cooperators’ clusters. Moreover, we examine the effects of the sample number on the evolution of cooperation. Our results highlight the importance of the detailed consideration of modes of interaction for the evolution of cooperation in well-mixed populations. PMID:22615761

  10. Sustainable cooperation based on reputation and habituation in the public goods game.

    PubMed

    Liu, Yan; Chen, Tong

    2017-10-01

    Reputation can promote cooperation in public goods game and player's cooperative behavior is not pure economical rationality, but habituation would influence their behaviors as well. One's habituation can be formed by repeated behaviors in daily life and be affected by habitual preference. We aim to investigate the sustainable cooperation based on reputation and habit formation. To better investigate the impacts of reputation and habitual preference on the evolution and sustainability of cooperation. We introduce three types of agents into our spatial public goods game. Through numerical simulations, we find that the larger habitual preference make cooperation easier to emerge and maintain. Additionally, we find that a moderate number of agents who want to obtain more reputation (ICs) are best for the sustainability of cooperation. Finally, we observe that the variation of donations of ICs can influence greatly on the equilibrium of public goods game. When ICs reduce their donations, a proper contribution will be better to maintain the cooperative behaviors. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Design of a Base Station for MEMS CCR Localization in an Optical Sensor Network

    PubMed Central

    Park, Chan Gook; Jeon, Hyun Cheol; Kim, Hyoun Jin; Kim, Jae Yoon

    2014-01-01

    This paper introduces a design and implementation of a base station, capable of positioning sensor nodes using an optical scheme. The base station consists of a pulse laser module, optical detectors and beam splitter, which are mounted on a rotation-stage, and a Time to Digital Converter (TDC). The optical pulse signal transmitted to the sensor node with a Corner Cube Retro-reflector (CCR) is reflected to the base station, and the Time of Flight (ToF) data can be obtained from the two detectors. With the angle and flight time data, the position of the sensor node can be calculated. The performance of the system is evaluated by using a commercial CCR. The sensor nodes are placed at different angles from the base station and scanned using the laser. We analyze the node position error caused by the rotation and propose error compensation methods, namely the outlier sample exception and decreasing the confidence factor steadily using the recursive least square (RLS) methods. Based on the commercial CCR results, the MEMS CCR is also tested to demonstrate the compatibility between the base station and the proposed methods. The result shows that the localization performance of the system can be enhanced with the proposed compensation method using the MEMS CCR. PMID:24815681

  12. Detecting Cooperativity between Transcription Factors Based on Functional Coherence and Similarity of Their Target Gene Sets

    PubMed Central

    Wu, Wei-Sheng; Lai, Fu-Jou

    2016-01-01

    In eukaryotic cells, transcriptional regulation of gene expression is usually achieved by cooperative transcription factors (TFs). Therefore, knowing cooperative TFs is the first step toward uncovering the molecular mechanisms of gene expression regulation. Many algorithms based on different rationales have been proposed to predict cooperative TF pairs in yeast. Although various types of rationales have been used in the existing algorithms, functional coherence is not yet used. This prompts us to develop a new algorithm based on functional coherence and similarity of the target gene sets to identify cooperative TF pairs in yeast. The proposed algorithm predicted 40 cooperative TF pairs. Among them, three (Pdc2-Thi2, Hot1-Msn1 and Leu3-Met28) are novel predictions, which have not been predicted by any existing algorithms. Strikingly, two (Pdc2-Thi2 and Hot1-Msn1) of the three novel predictions have been experimentally validated, demonstrating the power of the proposed algorithm. Moreover, we show that the predictions of the proposed algorithm are more biologically meaningful than the predictions of 17 existing algorithms under four evaluation indices. In summary, our study suggests that new algorithms based on novel rationales are worthy of developing for detecting previously unidentifiable cooperative TF pairs. PMID:27623007

  13. Odour-based kin discrimination in the cooperatively breeding meerkat.

    PubMed

    Leclaire, Sarah; Nielsen, Johanna F; Thavarajah, Nathan K; Manser, Marta; Clutton-Brock, Tim H

    2013-02-23

    Kin recognition is a useful ability for animals, facilitating cooperation among relatives and avoidance of excessive kin competition or inbreeding. In meerkats, Suricata suricatta, encounters between unfamiliar kin are relatively frequent, and kin recognition by phenotype matching is expected to avoid inbreeding with close relatives. Here, we investigate whether female meerkats are able to discriminate the scent of unfamiliar kin from unfamiliar non-kin. Dominant females were presented with anal gland secretion from unfamiliar individuals that varied in their relatedness. Our result indicates that females spent more time investigating the scent of related than unrelated unfamiliar individuals, suggesting that females may use a phenotype matching mechanism (or recognition alleles) to discriminate the odour of their kin from the odour of their non-kin. Our study provides a key starting point for further investigations into the use of kin recognition for inbreeding avoidance in the widely studied meerkat.

  14. Odour-based kin discrimination in the cooperatively breeding meerkat

    PubMed Central

    Leclaire, Sarah; Nielsen, Johanna F.; Thavarajah, Nathan K.; Manser, Marta; Clutton-Brock, Tim H.

    2013-01-01

    Kin recognition is a useful ability for animals, facilitating cooperation among relatives and avoidance of excessive kin competition or inbreeding. In meerkats, Suricata suricatta, encounters between unfamiliar kin are relatively frequent, and kin recognition by phenotype matching is expected to avoid inbreeding with close relatives. Here, we investigate whether female meerkats are able to discriminate the scent of unfamiliar kin from unfamiliar non-kin. Dominant females were presented with anal gland secretion from unfamiliar individuals that varied in their relatedness. Our result indicates that females spent more time investigating the scent of related than unrelated unfamiliar individuals, suggesting that females may use a phenotype matching mechanism (or recognition alleles) to discriminate the odour of their kin from the odour of their non-kin. Our study provides a key starting point for further investigations into the use of kin recognition for inbreeding avoidance in the widely studied meerkat. PMID:23234867

  15. [The electromagnetic fields of the base stations of mobile radio communication and ecology. The estimation of danger of the base station EMF for population and for bioecosystems].

    PubMed

    Grigor'ev, Iu G; Grigor'ev, K A

    2005-01-01

    The estimation of the danger for the population and for the bioecosistems of the electromagnetic conditions around of the base stations was given. The insufficiency of the scientific knowledge does not allow to guarantee the safety of the population and of the bioecosystems in the conditions of a round-the-clock long-term influence of EMF RF. WHO recommends to use "Precautionary principle".

  16. Novel Trajectory Control for Human Cooperation Robot Based on Behavior Mode Switching

    NASA Astrophysics Data System (ADS)

    Seki, Hirokazu; Takahashi, Kazuki; Tadakuma, Susumu

    This paper describes a novel trajectory control system for human cooperation robots based on behavior mode switching. Human cooperation robots have the great possibility to serve as useful support systems for elderly people and physically handicapped people and it is expected to realize the smooth and human-friendly support movements. This study defines three behavior modes in human cooperation motion and their respective trajectory control system are designed. In the trajectory design, minimum jerk model is introduced to realize the smooth and human-friendly cooperation movements. In addition, the initial value compensation at the mode switching is also developed. Some experiments on two-axis plane robot and performance evaluation by trial subjects show the effectiveness of the proposed trajectory control system.

  17. Practice and Evaluation of a Cooperative Learning Support on Educational Function as Teamwork in Project-based Learning with Regional Cooperation

    NASA Astrophysics Data System (ADS)

    Aoki, Hideyuki; Kamata, Motohiro; Yamagami, Norihisa

    The purpose of my study was to develop of cooperative learning support on Educational Function as Teamwork in Project-based Learning with Regional Cooperation. Analysis of validation of the original method were made using correlation analysis of student satisfaction of relationships among teammate and educational function as teamwork, result of self-diagnose. As a result, we achieved analysis results with a collective creativity were involved in student‧s planning skill. It was shown that educational functions as teamwork plays an important part in the growth of students. Our study revealed that there was method using cooperative learning technique helps to promote improvement of educational function as teamwork.

  18. 33 CFR 334.746 - U.S. Coast Guard, Destin Station at Eglin Air Force Base, Fla.; restricted area.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false U.S. Coast Guard, Destin Station... REGULATIONS § 334.746 U.S. Coast Guard, Destin Station at Eglin Air Force Base, Fla.; restricted area. (a) The... the area without the permission of the Commander, U.S. Coast Guard, Destin Station, Florida, or his...

  19. Consensus-Based Cooperative Control Based on Pollution Sensing and Traffic Information for Urban Traffic Networks

    PubMed Central

    Artuñedo, Antonio; del Toro, Raúl M.; Haber, Rodolfo E.

    2017-01-01

    Nowadays many studies are being conducted to develop solutions for improving the performance of urban traffic networks. One of the main challenges is the necessary cooperation among different entities such as vehicles or infrastructure systems and how to exploit the information available through networks of sensors deployed as infrastructures for smart cities. In this work an algorithm for cooperative control of urban subsystems is proposed to provide a solution for mobility problems in cities. The interconnected traffic lights controller (TLC) network adapts traffic lights cycles, based on traffic and air pollution sensory information, in order to improve the performance of urban traffic networks. The presence of air pollution in cities is not only caused by road traffic but there are other pollution sources that contribute to increase or decrease the pollution level. Due to the distributed and heterogeneous nature of the different components involved, a system of systems engineering approach is applied to design a consensus-based control algorithm. The designed control strategy contains a consensus-based component that uses the information shared in the network for reaching a consensus in the state of TLC network components. Discrete event systems specification is applied for modelling and simulation. The proposed solution is assessed by simulation studies with very promising results to deal with simultaneous responses to both pollution levels and traffic flows in urban traffic networks. PMID:28445398

  20. Consensus-Based Cooperative Control Based on Pollution Sensing and Traffic Information for Urban Traffic Networks.

    PubMed

    Artuñedo, Antonio; Del Toro, Raúl M; Haber, Rodolfo E

    2017-04-26

    Nowadays many studies are being conducted to develop solutions for improving the performance of urban traffic networks. One of the main challenges is the necessary cooperation among different entities such as vehicles or infrastructure systems and how to exploit the information available through networks of sensors deployed as infrastructures for smart cities. In this work an algorithm for cooperative control of urban subsystems is proposed to provide a solution for mobility problems in cities. The interconnected traffic lights controller (TLC) network adapts traffic lights cycles, based on traffic and air pollution sensory information, in order to improve the performance of urban traffic networks. The presence of air pollution in cities is not only caused by road traffic but there are other pollution sources that contribute to increase or decrease the pollution level. Due to the distributed and heterogeneous nature of the different components involved, a system of systems engineering approach is applied to design a consensus-based control algorithm. The designed control strategy contains a consensus-based component that uses the information shared in the network for reaching a consensus in the state of TLC network components. Discrete event systems specification is applied for modelling and simulation. The proposed solution is assessed by simulation studies with very promising results to deal with simultaneous responses to both pollution levels and traffic flows in urban traffic networks.

  1. Output power distributions of mobile radio base stations based on network measurements

    NASA Astrophysics Data System (ADS)

    Colombi, D.; Thors, B.; Persson, T.; Wirén, N.; Larsson, L.-E.; Törnevik, C.

    2013-04-01

    In this work output power distributions of mobile radio base stations have been analyzed for 2G and 3G telecommunication systems. The approach is based on measurements in selected networks using performance surveillance tools part of the network Operational Support System (OSS). For the 3G network considered, direct measurements of output power levels were possible, while for the 2G networks, output power levels were estimated from measurements of traffic volumes. Both voice and data services were included in the investigation. Measurements were conducted for large geographical areas, to ensure good overall statistics, as well as for smaller areas to investigate the impact of different environments. For high traffic hours, the 90th percentile of the averaged output power was found to be below 65% and 45% of the available output power for the 2G and 3G systems, respectively.

  2. Inquiry and groups: student interactions in cooperative inquiry-based science

    NASA Astrophysics Data System (ADS)

    Woods-McConney, Amanda; Wosnitza, Marold; Sturrock, Keryn L.

    2016-03-01

    Science education research has recommended cooperative inquiry based science in the primary science context for more than two decades but after more than 20 years, student achievement in science has not substantially improved. This study, through direct observation and analysis, investigated content-related student interactions in an authentic inquiry based primary science class setting. Thirty-one upper primary students were videotaped working in cooperative inquiry based science activities. Cooperative talk and negotiation of the science content was analysed to identify any high-level group interactions. The data show that while all groups have incidences of high-level content-related group interactions, the frequency and duration of these interactions were limited. No specific pattern of preceding events was identified and no episodes of high-level content-related group interactions were immediately preceded by the teacher's interactions with the groups. This in situ study demonstrated that even without any kind of scaffolding, specific skills in knowing how to implement cooperative inquiry based science, high-level content-related group interactions did occur very briefly. Support for teachers to develop their knowledge and skills in facilitating cooperative inquiry based science learning is warranted to ensure that high-level content-related group interactions and the associated conceptual learning are not left to chance in science classrooms.

  3. Efficient ways for setting up the operation of nuclear power stations in power systems in the base load mode

    NASA Astrophysics Data System (ADS)

    Aminov, R. Z.; Shkret, A. F.; Burdenkova, E. Yu.; Garievskii, M. V.

    2011-05-01

    The results obtained from studies of efficient ways and methods for organizing the operation of developing nuclear power stations in the base load mode are presented. We also show comparative efficiency of different scenarios for unloading condensing thermal power stations, cogeneration stations, combined-cycle power plants, nuclear power stations, and using off-peak electric energy for electricity-intensive loads: pumped-hydroelectric storage, electric-powered heat supply, and electrolysis of water for producing hydrogen and oxygen.

  4. Utilizing a Rapid Prototyping Approach in the Building of a Hypermedia-Based Reference Station.

    ERIC Educational Resources Information Center

    Sell, Dan

    This paper discusses the building of a hypermedia-based reference station at the Wright Laboratory Technical Library, Wright-Patterson Air Force Base, Ohio. Following this, the paper focuses on an electronic user survey from which data is collected and analysis is made. The survey data is used in a rapid prototyping approach, which is defined as…

  5. Analysis of lifetime of wireless sensor network with base station moving on different paths

    NASA Astrophysics Data System (ADS)

    Singh, Ashutosh Kumar; Purohit, N.; Varma, S.

    2014-05-01

    Energy saving is the top most requirement of the wireless sensor network (WSN) for making it a cost effective technology. In this direction, minimisation of the distance between the communicating nodes should be an obvious choice, as it consumes the biggest chunk of the node energy. But the stationary nature of nodes (including the base station) in the standard WSN does not allow it; thus, the provision of a moving base station has been recently introduced. A few schemes with moving base station have already been developed but they suffer from several drawbacks, for example, the path over which the base station can move has not been considered which is highly unfeasible. An efficient and implementable moving strategy is needed to be developed, which is the primary goal of the present work. The fuzzy logic inference mechanism has been developed and the performance of the same is illustrated in terms of WSN lifetime. Lifetime of a WSN depends on many factors, for example, residual energy of nodes, distance between communicating nodes and base station, etc. Ability of fuzzy logic theory to address more than one factor simultaneously gives it an upper edge over other alternatives. The present work explores the possibilities of building either a circular shaped or a cross-shaped path in the deployment area. A relative study of the movement of base station on these paths has been presented. Simulation results show that the cross path always give better performance than circular path and the lifetime improves with increase in the length of the predefined path.

  6. A Technical Approach to the Evaluation of Radiofrequency Radiation Emissions from Mobile Telephony Base Stations

    PubMed Central

    Buckus, Raimondas; Strukčinskienė, Birute; Raistenskis, Juozas; Stukas, Rimantas; Šidlauskienė, Aurelija; Čerkauskienė, Rimantė; Isopescu, Dorina Nicolina; Stabryla, Jan; Cretescu, Igor

    2017-01-01

    During the last two decades, the number of macrocell mobile telephony base station antennas emitting radiofrequency (RF) electromagnetic radiation (EMR) in residential areas has increased significantly, and therefore much more attention is being paid to RF EMR and its effects on human health. Scientific field measurements of public exposure to RF EMR (specifically to radio frequency radiation) from macrocell mobile telephony base station antennas and RF electromagnetic field (EMF) intensity parameters in the environment are discussed in this article. The research methodology is applied according to the requirements of safety norms and Lithuanian Standards in English (LST EN). The article presents and analyses RF EMFs generated by mobile telephony base station antennas in areas accessible to the general public. Measurements of the RF electric field strength and RF EMF power density were conducted in the near- and far-fields of the mobile telephony base station antenna. Broadband and frequency-selective measurements were performed outside (on the roof and on the ground) and in a residential area. The tests performed on the roof in front of the mobile telephony base station antennas in the near-field revealed the presence of a dynamic energy interaction within the antenna electric field, which changes rapidly with distance. The RF EMF power density values on the ground at distances of 50, 100, 200, 300, 400, and 500 m from the base station are very low and are scattered within intervals of 0.002 to 0.05 μW/cm2. The results were compared with international exposure guidelines (ICNIRP). PMID:28257069

  7. A Technical Approach to the Evaluation of Radiofrequency Radiation Emissions from Mobile Telephony Base Stations.

    PubMed

    Buckus, Raimondas; Strukčinskienė, Birute; Raistenskis, Juozas; Stukas, Rimantas; Šidlauskienė, Aurelija; Čerkauskienė, Rimantė; Isopescu, Dorina Nicolina; Stabryla, Jan; Cretescu, Igor

    2017-03-01

    During the last two decades, the number of macrocell mobile telephony base station antennas emitting radiofrequency (RF) electromagnetic radiation (EMR) in residential areas has increased significantly, and therefore much more attention is being paid to RF EMR and its effects on human health. Scientific field measurements of public exposure to RF EMR (specifically to radio frequency radiation) from macrocell mobile telephony base station antennas and RF electromagnetic field (EMF) intensity parameters in the environment are discussed in this article. The research methodology is applied according to the requirements of safety norms and Lithuanian Standards in English (LST EN). The article presents and analyses RF EMFs generated by mobile telephony base station antennas in areas accessible to the general public. Measurements of the RF electric field strength and RF EMF power density were conducted in the near- and far-fields of the mobile telephony base station antenna. Broadband and frequency-selective measurements were performed outside (on the roof and on the ground) and in a residential area. The tests performed on the roof in front of the mobile telephony base station antennas in the near-field revealed the presence of a dynamic energy interaction within the antenna electric field, which changes rapidly with distance. The RF EMF power density values on the ground at distances of 50, 100, 200, 300, 400, and 500 m from the base station are very low and are scattered within intervals of 0.002 to 0.05 μW/cm². The results were compared with international exposure guidelines (ICNIRP).

  8. Occupational exposure to base stations-compliance with EU directive 2004/40/EC.

    PubMed

    Gajsek, Peter; Simunić, Dina

    2006-01-01

    The rapid growth of mobile communications has not only led to a rising number of mobile telephones. It has also made base stations essential for these services widespread on many roofs. However, not everyone is aware that working close to sources of high frequency electromagnetic fields (EMF), such as transmitter antennas for mobile phones, pagers and police, fire and other emergency services, can result in high EMF exposure. This paper deals with measurements and calculations of the compliance boundary for workers in one typical roof top base station setting according to EU Directive and other relevant EN standards.

  9. Load forecast method of electric vehicle charging station using SVR based on GA-PSO

    NASA Astrophysics Data System (ADS)

    Lu, Kuan; Sun, Wenxue; Ma, Changhui; Yang, Shenquan; Zhu, Zijian; Zhao, Pengfei; Zhao, Xin; Xu, Nan

    2017-06-01

    This paper presents a Support Vector Regression (SVR) method for electric vehicle (EV) charging station load forecast based on genetic algorithm (GA) and particle swarm optimization (PSO). Fuzzy C-Means (FCM) clustering is used to establish similar day samples. GA is used for global parameter searching and PSO is used for a more accurately local searching. Load forecast is then regressed using SVR. The practical load data of an EV charging station were taken to illustrate the proposed method. The result indicates an obvious improvement in the forecasting accuracy compared with SVRs based on PSO and GA exclusively.

  10. Space Station based operations and maintenance support to spacecraft, platforms, and orbit transfer vehicle (OTV)

    NASA Technical Reports Server (NTRS)

    Steincamp, J. W.; Mulqueen, J. A.; Maloney, J. W.

    1984-01-01

    The orbital servicing concepts developed for several existing and planned spacecraft are reviewed to illustrate the evolution and capabilities of Shuttle-based support services, and the potential range of future services are categorized by several criteria including transportation systems requirements, supporting facilities and equipment options, and servicing locations. Implications of Space Station-basing the services are described, along with possible implementing systems. In particular, the technique of 'formation flying' by means of which spacecraft may be physically isolated from each other while maintaining reasonable propellant requirements for maneuvers between them is explored by representative examples. OTV mission support is described as an evolutionary augmentation of the basic Space Station services.

  11. Cooperative Operating Control Based on Virtual Resources and User-Suited HCI

    NASA Astrophysics Data System (ADS)

    Choinski, Dariusz; Metzger, Mieczyslaw; Nocon, Witold

    The paper presents concept of virtual resources (VR) which improve multilevel, remote Internet-based operation of real-time controlled industrial processes. In comparison to classical directly connected-to-plant operations, the VR-based system introduces all typical features of its flexible nature, hiding the unnecessary implementation details from the process operators. The user-suited, human-computer interfaces (HCI) improve cooperation between specialists who must carry out operating control of the process. Realisation of such a system is based on the concept of maximal usage of particular specialist’s skills improving theirs cooperation. Although the proposed concept is dedicated to remote operating experimentation on real-time controlled industrial plants, it has also a more general aspect. As a case example, the cooperative operating control of a biotechnological pilot-plant is presented.

  12. LQR-Based Optimal Distributed Cooperative Design for Linear Discrete-Time Multiagent Systems.

    PubMed

    Zhang, Huaguang; Feng, Tao; Liang, Hongjing; Luo, Yanhong

    2017-03-01

    In this paper, a novel linear quadratic regulator (LQR)-based optimal distributed cooperative design method is developed for synchronization control of general linear discrete-time multiagent systems on a fixed, directed graph. Sufficient conditions are derived for synchronization, which restrict the graph eigenvalues into a bounded circular region in the complex plane. The synchronizing speed issue is also considered, and it turns out that the synchronizing region reduces as the synchronizing speed becomes faster. To obtain more desirable synchronizing capacity, the weighting matrices are selected by sufficiently utilizing the guaranteed gain margin of the optimal regulators. Based on the developed LQR-based cooperative design framework, an approximate dynamic programming technique is successfully introduced to overcome the (partially or completely) model-free cooperative design for linear multiagent systems. Finally, two numerical examples are given to illustrate the effectiveness of the proposed design methods.

  13. Time averaged transmitter power and exposure to electromagnetic fields from mobile phone base stations.

    PubMed

    Bürgi, Alfred; Scanferla, Damiano; Lehmann, Hugo

    2014-08-07

    Models for exposure assessment of high frequency electromagnetic fields from mobile phone base stations need the technical data of the base stations as input. One of these parameters, the Equivalent Radiated Power (ERP), is a time-varying quantity, depending on communication traffic. In order to determine temporal averages of the exposure, corresponding averages of the ERP have to be available. These can be determined as duty factors, the ratios of the time-averaged power to the maximum output power according to the transmitter setting. We determine duty factors for UMTS from the data of 37 base stations in the Swisscom network. The UMTS base stations sample contains sites from different regions of Switzerland and also different site types (rural/suburban/urban/hotspot). Averaged over all regions and site types, a UMTS duty factor for the 24 h-average is obtained, i.e., the average output power corresponds to about a third of the maximum power. We also give duty factors for GSM based on simple approximations and a lower limit for LTE estimated from the base load on the signalling channels.

  14. Time Averaged Transmitter Power and Exposure to Electromagnetic Fields from Mobile Phone Base Stations

    PubMed Central

    Bürgi, Alfred; Scanferla, Damiano; Lehmann, Hugo

    2014-01-01

    Models for exposure assessment of high frequency electromagnetic fields from mobile phone base stations need the technical data of the base stations as input. One of these parameters, the Equivalent Radiated Power (ERP), is a time-varying quantity, depending on communication traffic. In order to determine temporal averages of the exposure, corresponding averages of the ERP have to be available. These can be determined as duty factors, the ratios of the time-averaged power to the maximum output power according to the transmitter setting. We determine duty factors for UMTS from the data of 37 base stations in the Swisscom network. The UMTS base stations sample contains sites from different regions of Switzerland and also different site types (rural/suburban/urban/hotspot). Averaged over all regions and site types, a UMTS duty factor F ≈ 0.32 ± 0.08 for the 24 h-average is obtained, i.e., the average output power corresponds to about a third of the maximum power. We also give duty factors for GSM based on simple approximations and a lower limit for LTE estimated from the base load on the signalling channels. PMID:25105551

  15. Differential roles of fairness- and compassion-based motivations for cooperation, defection, and punishment.

    PubMed

    Singer, Tania; Steinbeis, Nikolaus

    2009-06-01

    The present paper briefly describes and contrasts two different motivations crucially involved in decision making and cooperation, namely fairness-based and compassion-based motivation. Whereas both can lead to cooperation in comparable social situations, we suggest that they are driven by fundamentally different mechanisms and, overall, predict different behavioral outcomes. First, we provide a brief definition of each and discuss the relevant behavioral and neuroscientific literature with regards to cooperation in the context of economic games. We suggest that, whereas both fairness- and compassion-based motivation can support cooperation, fairness-based motivation leads to punishment in cases of norm violation, while compassion-based motivation can, in cases of defection, counteract a desire for revenge and buffer the decline into iterative noncooperation. However, those with compassion-based motivation alone may get exploited. Finally, we argue that the affective states underlying fairness-based and compassion-based motivation are fundamentally different, the former driven by anger or fear of being punished and the latter by a wish for the other person's well-being.

  16. When Creative Problem Solving Strategy Meets Web-Based Cooperative Learning Environment in Accounting Education

    ERIC Educational Resources Information Center

    Cheng, Kai Wen

    2011-01-01

    Background: Facing highly competitive and changing environment, cultivating citizens with problem-solving attitudes is one critical vision of education. In brief, the importance of education is to cultivate students with practical abilities. Realizing the advantages of web-based cooperative learning (web-based CL) and creative problem solving…

  17. Generic supervisor: A knowledge-based tool for control of space station on-board systems

    NASA Technical Reports Server (NTRS)

    Carnes, J. R.; Nelson, R.

    1988-01-01

    The concept of a generic module for management of onboard systems grew out of the structured analysis effort for the Space Station software. Hierarchical specification of subsystems software revealed that nontrivial supervisory elements are required at all levels. The number of supervisors (and subsequent software) required to implement the hierarchical control over onboard functions comprise a large portion of the Space Station software. Thus, a generic knowledge based supervisory module significantly reduces the amount of software developed. This module, the Generic Supervisor, depends on its knowledge of control to provide direction for subordinates and feedback to superiors within a specific subsystem area. The Generic Supervisor provides an adaptable and maintainable control system. A portion of the Space Station Environmental Control and Life Support System (ECLSS) was implemented as a hierarchy of supervisors. This prototype implementation demonstrates the feasibility of a generic knowledge based supervisor, and its facility to meet complex mission requirements.

  18. Generic supervisor: A knowledge-based tool for control of space station on-board systems

    NASA Technical Reports Server (NTRS)

    Carnes, J. R.; Nelson, R.

    1988-01-01

    The concept of a generic module for management of onboard systems grew out of the structured analysis effort for the Space Station software. Hierarchical specification of subsystems software revealed that nontrivial supervisory elements are required at all levels. The number of supervisors (and subsequent software) required to implement the hierarchical control over onboard functions comprise a large portion of the Space Station software. Thus, a generic knowledge based supervisory module significantly reduces the amount of software developed. This module, the Generic Supervisor, depends on its knowledge of control to provide direction for subordinates and feedback to superiors within a specific subsystem area. The Generic Supervisor provides an adaptable and maintainable control system. A portion of the Space Station Environmental Control and Life Support System (ECLSS) was implemented as a hierarchy of supervisors. This prototype implementation demonstrates the feasibility of a generic knowledge based supervisor, and its facility to meet complex mission requirements.

  19. Statistical analysis of electromagnetic radiation measurements in the vicinity of indoor microcell GSM/UMTS base stations in Serbia.

    PubMed

    Koprivica, Mladen; Petrić, Majda; Nešković, Nataša; Nešković, Aleksandar

    2016-01-01

    To determine the level of radiofrequency radiation generated by base stations of Global System for Mobile Communications and Universal Mobile Telecommunication System, extensive electromagnetic field strength measurements were carried out in the vicinity of 664 base station locations. These were classified into three categories: indoor, masts, and locations with installations on buildings. Although microcell base stations with antennas installed indoors typically emit less power than outdoor macrocell base stations, the fact that people can be found close to antennas requires exposure originating from these base stations to be carefully considered. Measurement results showed that maximum recorded value of electric field strength exceeded International Commission on Non-Ionizing Radiation Protection reference levels at 7% of indoor base station locations. At the same time, this percentage was much lower in the case of masts and installations on buildings (0% and 2.5%, respectively). © 2015 Wiley Periodicals, Inc.

  20. Computer-based training system for the diagnosis of failure in the flow station

    SciTech Connect

    Villalobos, A.; Rosales, O.; Granadillo, A.

    1994-12-31

    This paper will refer to the design and implementation of a computer based training system for diagnosing failures that lead to automatic shutdown due to high levels in the tank, in flow stations on Maracaibo Lake, Venezuela. The project includes three basic modules: The Computer Assisted Instruction (CAI): Constituted by three lessons and its corresponding evaluations; Computer Management Instruction (CMI): To control the instruction material; The Expert System (ES): Selected as a learning resource. The operation for diagnosing failures requires from certain experience to be accomplished efficiently. The flow station receive, separate, temporarily store and pump fluids coming from nearby wells. They are basic elements in petroleum production and for this reason, production treatment from nearby wells depends on their functioning and properly. When an automatic close of station is produced the automatic income valves of crude at the separators are closed bringing as consequence that the production is remained trapped in the manifold of production. The time that the station remains closed represent the deferred production. The computer-based training system contributes to improve the productivity of the flow station operations.

  1. Digital data-acquisition system for use with a proton-precession base-station magnetometer

    SciTech Connect

    McPherron, R.L.

    1982-08-26

    At UCLA the base station magnetometer is a Scintrex MB -2 which uses a two inch wide chart record scaled to 100 nT. The magnetometer is also equipped with a digital readout. This is available in BCD format on a 37 pin connector at the back of the instrument. This reading may be recorded digitally if an appropriate data acquisition and storage system is available. The recent development of inexpensive microcomputers and audio cassette recorders provided motivation for our exploration group to develop a digital data acquisition system for the existing base station magnetometer. A block diagram of the data acquisition system is presented. The microcomputer utilizes a R6502 as the central processor. Data are entered into the computer via a 12 key keypad and are displayed on a 6 digit liquid crystal display. Data from the Scintrex base magnetometer is passed to the microcomputer via a 37 line connector. One line of this connector is used to signal the status of the internally controlled sampling circuit in the base station magnetometer. Digital data are stored temporarily in RAM memory until an output buffer is filled. When this occurs power is applied to the audio cassette tape transport mechanism and after a short delay a block of data is written onto tape. The tape interface implements the Kansas City standard which is nearly universally used for microcomputer recording on audio cassette recorders. The entire system is powered by the same 12V dc battery used by the base station magnetometer. (WHK)

  2. Streamflow characteristics based on data through water year 2009 for selected streamflow-gaging stations in or near Montana: Chapter E in Montana StreamStats

    USGS Publications Warehouse

    McCarthy, Peter M.

    2016-04-05

    Chapter E of this Scientific Investigations Report documents results from a study by the U.S. Geological Survey, in cooperation with the Montana Department of Environmental Quality and the Montana Department of Natural Resources and Conservation, to provide an update of statewide streamflow characteristics based on data through water year 2009 for streamflow-gaging stations in or near Montana. Streamflow characteristics are presented for 408 streamflow-gaging stations in Montana and adjacent areas having 10 or more years of record. Data include the magnitude and probability of annual low and high streamflow, the magnitude and probability of low streamflow for three seasons (March–June, July–October, and November–February), streamflow duration statistics for monthly and annual periods, and mean streamflows for monthly and annual periods. Streamflow is considered to be regulated at streamflow-gaging stations where dams or other large-scale human modifications affect 20 percent or more of the contributing drainage basin. Separate streamflow characteristics are presented for the unregulated and regulated periods of record for streamflow-gaging stations with sufficient data.

  3. Radio frequency electromagnetic field compliance assessment of multi-band and MIMO equipped radio base stations.

    PubMed

    Thors, Björn; Thielens, Arno; Fridén, Jonas; Colombi, Davide; Törnevik, Christer; Vermeeren, Günter; Martens, Luc; Joseph, Wout

    2014-05-01

    In this paper, different methods for practical numerical radio frequency exposure compliance assessments of radio base station products were investigated. Both multi-band base station antennas and antennas designed for multiple input multiple output (MIMO) transmission schemes were considered. For the multi-band case, various standardized assessment methods were evaluated in terms of resulting compliance distance with respect to the reference levels and basic restrictions of the International Commission on Non-Ionizing Radiation Protection. Both single frequency and multiple frequency (cumulative) compliance distances were determined using numerical simulations for a mobile communication base station antenna transmitting in four frequency bands between 800 and 2600 MHz. The assessments were conducted in terms of root-mean-squared electromagnetic fields, whole-body averaged specific absorption rate (SAR) and peak 10 g averaged SAR. In general, assessments based on peak field strengths were found to be less computationally intensive, but lead to larger compliance distances than spatial averaging of electromagnetic fields used in combination with localized SAR assessments. For adult exposure, the results indicated that even shorter compliance distances were obtained by using assessments based on localized and whole-body SAR. Numerical simulations, using base station products employing MIMO transmission schemes, were performed as well and were in agreement with reference measurements. The applicability of various field combination methods for correlated exposure was investigated, and best estimate methods were proposed. Our results showed that field combining methods generally considered as conservative could be used to efficiently assess compliance boundary dimensions of single- and dual-polarized multicolumn base station antennas with only minor increases in compliance distances.

  4. Pedestrian movement analysis in transfer station corridor: Velocity-based and acceleration-based

    NASA Astrophysics Data System (ADS)

    Ji, Xiangfeng; Zhang, Jian; Hu, Yongkai; Ran, Bin

    2016-05-01

    In this paper, pedestrians are classified into aggressive and conservative ones by their temper. Aggressive pedestrians' walking through crowd in transfer station corridor is analyzed. Treating pedestrians as particles, this paper uses the modified social force model (MSFM) as the building block, where forces involve self-driving force, repulsive force and friction force. The proposed model in this paper is a discrete model combining the MSFM and cellular automata (CA) model, where the updating rules of the CA are redefined with MSFM. Due to the continuity of values generated by the MSFM, we use the fuzzy logic to discretize the continuous values into cells pedestrians can move in one step. With the observation that stimulus around pedestrians influences their acceleration directly, an acceleration-based movement model is presented, compared to the generally reviewed velocity-based movement model. In the acceleration-based model, a discretized version of kinematic equation is presented based on the acceleration discretized with fuzzy logic. In real life, some pedestrians would rather keep their desired speed and this is also mimicked in this paper, which is called inertia. Compared to the simple triangular membership function, a trapezoidal membership function and a piecewise linear membership function are used to capture pedestrians' inertia. With the trapezoidal and the piecewise linear membership function, many overlapping scenarios should be carefully handled and Dubois and Prade's four-index method is used to completely describe the relative relationship of fuzzy quantities. Finally, a simulation is constructed to demonstrate the effect of our model.

  5. Multi Groups Cooperation based Symbiotic Evolution for TSK-type Neuro-Fuzzy Systems Design

    PubMed Central

    Cheng, Yi-Chang; Hsu, Yung-Chi

    2010-01-01

    In this paper, a TSK-type neuro-fuzzy system with multi groups cooperation based symbiotic evolution method (TNFS-MGCSE) is proposed. The TNFS-MGCSE is developed from symbiotic evolution. The symbiotic evolution is different from traditional GAs (genetic algorithms) that each chromosome in symbiotic evolution represents a rule of fuzzy model. The MGCSE is different from the traditional symbiotic evolution; with a population in MGCSE is divided to several groups. Each group formed by a set of chromosomes represents a fuzzy rule and cooperate with other groups to generate the better chromosomes by using the proposed cooperation based crossover strategy (CCS). In this paper, the proposed TNFS-MGCSE is used to evaluate by numerical examples (Mackey-Glass chaotic time series and sunspot number forecasting). The performance of the TNFS-MGCSE achieves excellently with other existing models in the simulations. PMID:21709856

  6. Multi Groups Cooperation based Symbiotic Evolution for TSK-type Neuro-Fuzzy Systems Design.

    PubMed

    Cheng, Yi-Chang; Hsu, Yung-Chi; Lin, Sheng-Fuu

    2010-07-01

    In this paper, a TSK-type neuro-fuzzy system with multi groups cooperation based symbiotic evolution method (TNFS-MGCSE) is proposed. The TNFS-MGCSE is developed from symbiotic evolution. The symbiotic evolution is different from traditional GAs (genetic algorithms) that each chromosome in symbiotic evolution represents a rule of fuzzy model. The MGCSE is different from the traditional symbiotic evolution; with a population in MGCSE is divided to several groups. Each group formed by a set of chromosomes represents a fuzzy rule and cooperate with other groups to generate the better chromosomes by using the proposed cooperation based crossover strategy (CCS). In this paper, the proposed TNFS-MGCSE is used to evaluate by numerical examples (Mackey-Glass chaotic time series and sunspot number forecasting). The performance of the TNFS-MGCSE achieves excellently with other existing models in the simulations.

  7. Research on multirobot pursuit task allocation algorithm based on emotional cooperation factor.

    PubMed

    Fang, Baofu; Chen, Lu; Wang, Hao; Dai, Shuanglu; Zhong, Qiubo

    2014-01-01

    Multirobot task allocation is a hot issue in the field of robot research. A new emotional model is used with the self-interested robot, which gives a new way to measure self-interested robots' individual cooperative willingness in the problem of multirobot task allocation. Emotional cooperation factor is introduced into self-interested robot; it is updated based on emotional attenuation and external stimuli. Then a multirobot pursuit task allocation algorithm is proposed, which is based on emotional cooperation factor. Combined with the two-step auction algorithm recruiting team leaders and team collaborators, set up pursuit teams, and finally use certain strategies to complete the pursuit task. In order to verify the effectiveness of this algorithm, some comparing experiments have been done with the instantaneous greedy optimal auction algorithm; the results of experiments show that the total pursuit time and total team revenue can be optimized by using this algorithm.

  8. Non-cooperative spacecraft pose tracking based on point cloud feature

    NASA Astrophysics Data System (ADS)

    He, Ying; Liang, Bin; He, Jin; Li, Shunzhi

    2017-10-01

    On-orbit services have been paid more and more attention for its role in spacecraft life-extension, capacity improvement and on-orbit debris removal. As most of on-orbit targets are non-cooperative, relatively accurate pose measurement is very essential for subsequent operations. However, with the rapid development of TriDAR, flash LIDAR and other laser scanning equipment in non-cooperative target measurement, it becomes more imperative to research methods for non-cooperative target pose tracking based on 3D point cloud feature. In this paper, a method for non-cooperative target pose tracking based on point cloud feature is proposed. Firstly, the target is identified using curvature, normal, density and other geometric features of the point cloud. Then the particle filter algorithm is used to recognize the position and orientation of the target being tracked by calculating the similarity of the point cloud features of two adjacent frames. Experimental results showed that the proposed method could effectively identify the features of non-cooperative targets and track their position and attitude.

  9. 47 CFR 90.656 - Responsibilities of base station licensees of Specialized Mobile Radio systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Specialized Mobile Radio systems. 90.656 Section 90.656 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Regulations Governing... Bands § 90.656 Responsibilities of base station licensees of Specialized Mobile Radio systems. (a) The...

  10. 47 CFR 90.656 - Responsibilities of base station licensees of Specialized Mobile Radio systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Specialized Mobile Radio systems. 90.656 Section 90.656 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Regulations Governing... Bands § 90.656 Responsibilities of base station licensees of Specialized Mobile Radio systems. (a) The...

  11. 47 CFR 90.656 - Responsibilities of base station licensees of Specialized Mobile Radio systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Specialized Mobile Radio systems. 90.656 Section 90.656 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Regulations Governing... Bands § 90.656 Responsibilities of base station licensees of Specialized Mobile Radio systems. (a) The...

  12. 47 CFR 90.656 - Responsibilities of base station licensees of Specialized Mobile Radio systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Specialized Mobile Radio systems. 90.656 Section 90.656 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Regulations Governing... Bands § 90.656 Responsibilities of base station licensees of Specialized Mobile Radio systems. (a) The...

  13. 47 CFR 90.656 - Responsibilities of base station licensees of Specialized Mobile Radio systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Specialized Mobile Radio systems. 90.656 Section 90.656 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Regulations Governing... Bands § 90.656 Responsibilities of base station licensees of Specialized Mobile Radio systems. (a) The...

  14. POLLUTION PREVENTION OPPORTUNITY ASSESSMENT - UNITED STATES NAVAL BASE NORFOLK NAVAL AIR STATION

    EPA Science Inventory

    This report summarizes work conducted at the U.S. Navy's Naval Base Norfolk, Naval Air Station (NAS) located at Sewells Point in Norfolk, Virginia, under the U.S. Environmental Protection Agency's (EPA) Waste Reduction Evaluations at Federal Sites (WREAFS) Program. This project w...

  15. Microprocessor-based control of the photovoltaic solar power system for an AM radio station

    SciTech Connect

    Much, C. H.; Rothenheber, P. J.

    1980-01-01

    A microprocessor-based controller for a 15 kW photovoltaic power system powering an AM radio station keeps dc bus voltage between desired limits, governs battery operation, monitors safety conditions, and provides status reporting. The microprocessor also facilitates complicated algorithms that improve performance. The first three months of system operation are presented.

  16. Effect of electromagnetic radiations from mobile phone base stations on general health and salivary function

    PubMed Central

    Singh, Kushpal; Nagaraj, Anup; Yousuf, Asif; Ganta, Shravani; Pareek, Sonia; Vishnani, Preeti

    2016-01-01

    Objective: Cell phones use electromagnetic, nonionizing radiations in the microwave range, which some believe may be harmful to human health. The present study aimed to determine the effect of electromagnetic radiations (EMRs) on unstimulated/stimulated salivary flow rate and other health-related problems between the general populations residing in proximity to and far away from mobile phone base stations. Materials and Methods: A total of four mobile base stations were randomly selected from four zones of Jaipur, Rajasthan, India. Twenty individuals who were residing in proximity to the selected mobile phone towers were taken as the case group and the other 20 individuals (control group) who were living nearly 1 km away in the periphery were selected for salivary analysis. Questions related to sleep disturbances were measured using Pittsburgh Sleep Quality Index (PSQI) and other health problems were included in the questionnaire. Chi-square test was used for statistical analysis. Results: It was unveiled that a majority of the subjects who were residing near the mobile base station complained of sleep disturbances, headache, dizziness, irritability, concentration difficulties, and hypertension. A majority of the study subjects had significantly lesser stimulated salivary secretion (P < 0.01) as compared to the control subjects. Conclusions: The effects of prolonged exposure to EMRs from mobile phone base stations on the health and well-being of the general population cannot be ruled out. Further studies are warranted to evaluate the effect of electromagnetic fields (EMFs) on general health and more specifically on oral health. PMID:27011934

  17. POLLUTION PREVENTION OPPORTUNITY ASSESSMENT - UNITED STATES NAVAL BASE NORFOLK NAVAL AIR STATION

    EPA Science Inventory

    This report summarizes work conducted at the U.S. Navy's Naval Base Norfolk, Naval Air Station (NAS) located at Sewells Point in Norfolk, Virginia, under the U.S. Environmental Protection Agency's (EPA) Waste Reduction Evaluations at Federal Sites (WREAFS) Program. This project w...

  18. Research Station "Ice Base "Cape Baranov"- overview of activities in 2013 - 2015 years

    NASA Astrophysics Data System (ADS)

    Makshtas, Alexander; Sokolov, Vladimir; Bogorodskii, Peter; Kustov, Vasily; Movchan, Vadim; Laurila, Tuomas; Asmi, Eija; Popovicheva, Olga; Eleftheriadis, Kostas

    2016-04-01

    Research Station "Ice base "Cape Baranov" of Arctic and Antarctic Research Institute (AARI) had been opened in the fall 2013 on the Bolshevik Island, Archipelago Severnaya Zemlia. Now it is going as the integrated observatory, conducting comprehensive studies in practically all areas of Earth Sciences: from free atmosphere to sea ice and sea water structure in the Shokalsky Strait, from glaciers to permafrost, from paleogeography to ornithology. Overview of activities together with some preliminary results of field works at the station performing in 2014 - 2015 years by international multidisciplinary team in frame of free atmosphere, atmospheric surface layer, greenhouse gases and aerosol studies is presented together with model estimations of active soil layer.

  19. Tectonic Plate Parameters Estimated in the International Terrestrial Reference Frame ITRF2008 Based on SLR Stations

    NASA Astrophysics Data System (ADS)

    Kraszewska, Katarzyna; Jagoda, Marcin; Rutkowska, Miłosława

    2016-10-01

    This paper concerns an analysis of the accuracy of estimated parameters Ω (Φ, Λ, ω) which define the tectonic plate motions. The study is based on the velocities of station positions published by ITRF2008 for Satellite Laser Ranging (SLR) technique. The Eurasian, African, North American and Australian plates were used in the analysis. Influence of the number and location of stations on the plate surface on estimation accuracy of the tectonic plate motion parameters was discussed. The results were compared with the APKIM 2005 IGN model. In general, a remarkable concurrence agreement between our solutions and the APKIM 2005 model was found.

  20. Public safety assessment of electromagnetic radiation exposure from mobile base stations.

    PubMed

    Alhekail, Z O; Hadi, M A; Alkanhal, M A

    2012-09-01

    Exposure of the general public to electromagnetic radiation originating from randomly selected GSM/WCDMA base stations in Riyadh, Kingdom of Saudi Arabia has been assessed in the context of the International Commission on Non-Ionising Radiation Protection (ICNIRP) guidelines. The purpose of the measurement was to record the maximum power density of signals to estimate possible worst case exposure at each measurement location. These power density measurements were carried out at 60 mobile base stations located in different regions of the city. For each of these sites, three sectors were operational, yielding a total of 180 sectors. Two positions were identified per site with the greatest power density values. Exposures from these base stations were generally found to be in the range of 0.313 to 0.00000149% of the ICNIRP general public reference level, and the greatest exposure near any of the base stations was 21.96 mW m(-2) for a wideband measurement in the 75-3000 MHz frequency range. Analysis of the measured data reveals several trends for different mobile bands with respect to maximum exposure in those locations. Additionally, a simplified calculation method for the electromagnetic fields was used to compare calculated and the measured data. It was determined, on the basis of both results of the measurements and calculations carried out for these selected base stations, that members of the public would not be exposed to in excess of a small fraction of the ICNIRP guidelines at any of those sites. These are first such measurements to be made in the Middle East and provide assurance that exposures in this region of the world do not seem to be any greater than elsewhere.

  1. Cooperative operation of urban drainage facilities

    NASA Astrophysics Data System (ADS)

    Kim, Joong Hoon; Lee, Eui Hoon; Lim, Osung; Jung, Donghwi

    2017-04-01

    Management of drainage facilities is an important factor in urban flooding. In the past, structural management including the installation of additional drainage facilities have been adopted to prevent urban flooding as a main policy although it is costly and time consuming. Non-structural management such as effective operation of drainage facilities is necessary to raise the flood mitigation efficiency. In this study, a new type of management, cooperative operation for urban drainage facilities including pump stations and detention reservoirs, is suggested. A novel cooperative operating management is proposed as a nonstructural management. The proposed operational management are demonstrated in the Daerim sewer network in Seoul, South Korea with a detention reservoir at the upstream of the study network and a pump station at the downstream. The new cooperative operation is based on sharing water level information at monitoring nodes and controlling drainage pumps. Results describe that flood reduction by the management of cooperative operation are better than the management of current operation. All results related to flood reduction by the cooperative operation are superior to those by the current operation. Key words: Urban flooding, Pump station, Detention reservoir, Cooperative operation, Urban drainage facilities

  2. Network-based criterion for the success of cooperation in an evolutionary prisoner's dilemma.

    PubMed

    Devlin, Stephen; Treloar, Thomas

    2012-08-01

    We consider an evolutionary prisoner's dilemma on a random network. We introduce a simple quantitative network-based parameter and show that it effectively predicts the success of cooperation in simulations on the network. The criterion is shown to be accurate on a variety of networks with degree distributions ranging from regular to Poisson to scale free. The parameter allows for comparisons of random networks regardless of their underlying topology. Finally, we draw analogies between the criterion for the success of cooperation introduced here and existing criteria in other contexts.

  3. Subject combination and electrode selection in cooperative brain-computer interface based on event related potentials.

    PubMed

    Cecotti, Hubert; Rivet, Bertrand

    2014-04-30

    New paradigms are required in Brain-Computer Interface (BCI) systems for the needs and expectations of healthy people. To solve this issue, we explore the emerging field of cooperative BCIs, which involves several users in a single BCI system. Contrary to classical BCIs that are dependent on the unique subject's will, cooperative BCIs are used for problem solving tasks where several people shall be engaged by sharing a common goal. Similarly as combining trials over time improves performance, combining trials across subjects can significantly improve performance compared with when only a single user is involved. Yet, cooperative BCIs may only be used in particular settings, and new paradigms must be proposed to efficiently use this approach. The possible benefits of using several subjects are addressed, and compared with current single-subject BCI paradigms. To show the advantages of a cooperative BCI, we evaluate the performance of combining decisions across subjects with data from an event-related potentials (ERP) based experiment where each subject observed the same sequence of visual stimuli. Furthermore, we show that it is possible to achieve a mean AUC superior to 0.95 with 10 subjects and 3 electrodes on each subject, or with 4 subjects and 6 electrodes on each subject. Several emerging challenges and possible applications are proposed to highlight how cooperative BCIs could be efficiently used with current technologies and leverage BCI applications.

  4. Understanding Cooperative Behavior Based on the Coevolution of Game Strategy and Link Weight.

    PubMed

    Huang, Keke; Zheng, Xiaoping; Li, Zhijie; Yang, Yeqing

    2015-10-05

    In reality, the dependency relationship among individuals is heterogeneous and time-varying. Based on this fact, we present a new mechanism of coevolution of game strategy and link weight when analyzing the evolution of cooperation. In detail, we model the population on a regular network, on which the relationship between players is depicted by a weighted link, and prisoner's dilemma has been applied to describe the interaction of players. Further, the impact of this mechanism on the cooperative behavior has been outlined. By conducting large-scale Monte Carlo simulations, we can easily draw a conclusion that this mechanism can promote cooperation efficiently. Compared with the traditional case, when the temptation of defection b is large, the fraction of cooperation is still able to keep in a high level. With a comprehensive examination of the distribution of stable link weight, it is evident that the coevolution mechanism would deviate the initial distribution. This mechanism induces the heterogeneity of players, which enhances the fraction of cooperation. Numerical simulations also indicate that an intermediate value of Δ/δ warrants an optimal resolution of prisoner's dilemma. The mechanism of coevolution of game strategy and link weight has a practical significance and will provide new insight for the further research.

  5. The effect of problem-based learning with cooperative-learning strategies in surgery clerkships.

    PubMed

    Turan, Sevgi; Konan, Ali; Kılıç, Yusuf Alper; Özvarış, Şevkat Bahar; Sayek, Iskender

    2012-01-01

    Cooperative learning is used often as part of the problem-based learning (PBL) process. But PBL does not demand that students work together until all individuals master the material or share the rewards for their work together. A cooperative learning and assessment structure was introduced in a PBL course in 10-week surgery clerkship, and the difference was evaluated between this method and conventional PBL in an acute abdominal pain module. An experimental design was used. No significant differences in achievement were found between the study and control group. Both the study and control group students who scored low on the pretest made the greatest gains at the end of the education. Students in the cooperative learning group felt that cooperation helped them learn, it was fun to study and expressed satisfaction, but they complained about the amount of time the groups had to work together, difficulties of group work, and noise during the sessions. This study evaluated the impact of a cooperative learning technique (student team learning [STL]) in PBL and found no differences. The study confirms that a relationship exists between allocated study time and achievement, and student's satisfaction about using this technique. Copyright © 2012 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

  6. Understanding Cooperative Behavior Based on the Coevolution of Game Strategy and Link Weight

    NASA Astrophysics Data System (ADS)

    Huang, Keke; Zheng, Xiaoping; Li, Zhijie; Yang, Yeqing

    2015-10-01

    In reality, the dependency relationship among individuals is heterogeneous and time-varying. Based on this fact, we present a new mechanism of coevolution of game strategy and link weight when analyzing the evolution of cooperation. In detail, we model the population on a regular network, on which the relationship between players is depicted by a weighted link, and prisoner’s dilemma has been applied to describe the interaction of players. Further, the impact of this mechanism on the cooperative behavior has been outlined. By conducting large-scale Monte Carlo simulations, we can easily draw a conclusion that this mechanism can promote cooperation efficiently. Compared with the traditional case, when the temptation of defection b is large, the fraction of cooperation is still able to keep in a high level. With a comprehensive examination of the distribution of stable link weight, it is evident that the coevolution mechanism would deviate the initial distribution. This mechanism induces the heterogeneity of players, which enhances the fraction of cooperation. Numerical simulations also indicate that an intermediate value of Δ/δ warrants an optimal resolution of prisoner’s dilemma. The mechanism of coevolution of game strategy and link weight has a practical significance and will provide new insight for the further research.

  7. A Model of Solid Waste Management Based Multilateral Co-Operation in Semi-Urban Community

    ERIC Educational Resources Information Center

    Kanchanabhandhu, Chanchai; Woraphong, Seree

    2016-01-01

    The purpose of this research was to construct a model of solid waste management based on multilateral cooperation in semi-urban community. Its specific objectives were to 1) study the solid waste situation and involvement of community in the solid waste management in Wangtaku Sub-district, Muang District, Nakhon Pathom Province; 2) construct a…

  8. Leadership in University-Based Cooperative Research Centres: A Qualitative Investigation of Performance Dimensions

    ERIC Educational Resources Information Center

    Craig, S. Bartholomew; Hess, Clara E.; McGinnis, Jennifer Lindberg; Gray, Denis O.

    2009-01-01

    In spite of the importance often attached to the role played by leadership in university-based cooperative research centres, we know very little about what "leadership" means in this specific context. The research reported here used a qualitative approach to identify fifteen dimensions of leadership performance for directors of university-based…

  9. The Effects of Jigsaw Technique Based on Cooperative Learning on Prospective Science Teachers' Science Process Skill

    ERIC Educational Resources Information Center

    Karacop, Ataman; Diken, Emine Hatun

    2017-01-01

    The purpose of this study is to investigate the effects of laboratory approach based on jigsaw method with cooperative learning and confirmatory laboratory approach on university students' cognitive process development in Science teaching laboratory applications, and to determine the opinions of the students on applied laboratory methods. The…

  10. Reflection in Example- and Problem-Based Learning: Effects of Reflection Prompts, Feedback and Cooperative Learning

    ERIC Educational Resources Information Center

    Krause, Ulrike-Marie; Stark, Robin

    2010-01-01

    To examine the effects of reflection prompts, elaborated feedback and cooperation on learning and reflection, two experimental studies were conducted. For both studies, an example- and problem-based e-learning environment on correlation was used. In Study 1, 57 university students were randomly assigned to two conditions: with reflection prompts…

  11. Competency Based Core Curriculum for Distributive Education and Diversified Cooperative Training.

    ERIC Educational Resources Information Center

    Mobley, Robert G.; And Others

    This document contains separate core curricula for Distributive Education and Diversified Cooperative Training programs designed to aid the teacher in using available competency-based instructional materials. Each core curriculum is composed of four parts: marketing, economics, career exploration, and employability skills. Marketing, the largest…

  12. Design and Implementation of a Project-Based Active/Cooperative Engineering Design Course for Freshmen

    ERIC Educational Resources Information Center

    Abdulaal, R. M.; Al-Bahi, A. M.; Soliman, A. Y.; Iskanderani, F. I.

    2011-01-01

    A project-based active/cooperative design course is planned, implemented, assessed and evaluated to achieve several desired engineering outcomes. The course allows freshman-level students to gain professional hands-on engineering design experience through an opportunity to practise teamwork, quality principles, communication skills, life-long…

  13. Design and Implementation of a Project-Based Active/Cooperative Engineering Design Course for Freshmen

    ERIC Educational Resources Information Center

    Abdulaal, R. M.; Al-Bahi, A. M.; Soliman, A. Y.; Iskanderani, F. I.

    2011-01-01

    A project-based active/cooperative design course is planned, implemented, assessed and evaluated to achieve several desired engineering outcomes. The course allows freshman-level students to gain professional hands-on engineering design experience through an opportunity to practise teamwork, quality principles, communication skills, life-long…

  14. Optimal guidance law for cooperative attack of multiple missiles based on optimal control theory

    NASA Astrophysics Data System (ADS)

    Sun, Xiao; Xia, Yuanqing

    2012-08-01

    This article considers the problem of optimal guidance laws for cooperative attack of multiple missiles based on the optimal control theory. New guidance laws are presented such that multiple missiles attack a single target simultaneously. Simulation results show the effectiveness of the proposed algorithms.

  15. Successful Group Work: Using Cooperative Learning and Team-Based Learning in the Classroom

    ERIC Educational Resources Information Center

    Grant-Vallone, E. J.

    2011-01-01

    This research study examined student perceptions of group experiences in the classroom. The author used cooperative learning and team-based learning to focus on three characteristics that are critical for the success of groups: structure of activities, relationships of group members, and accountability of group members. Results indicated that…

  16. Reflection in Example- and Problem-Based Learning: Effects of Reflection Prompts, Feedback and Cooperative Learning

    ERIC Educational Resources Information Center

    Krause, Ulrike-Marie; Stark, Robin

    2010-01-01

    To examine the effects of reflection prompts, elaborated feedback and cooperation on learning and reflection, two experimental studies were conducted. For both studies, an example- and problem-based e-learning environment on correlation was used. In Study 1, 57 university students were randomly assigned to two conditions: with reflection prompts…

  17. A Journal-Club-Based Class that Promotes Active and Cooperative Learning of Biology

    ERIC Educational Resources Information Center

    Kitazono, Ana A.

    2010-01-01

    A journal-club-based class has been developed to promote active and cooperative learning and expose seniors in biochemistry and cellular molecular biology to recent research in the field. Besides giving oral presentations, students also write three papers: one discussing an article of their own choosing and two, discussing articles presented by…

  18. Raising Awareness of Assistive Technology in Older Adults through a Community-Based, Cooperative Extension Program

    ERIC Educational Resources Information Center

    Sellers, Debra M.; Markham, Melinda Stafford

    2012-01-01

    The Fashion an Easier Lifestyle with Assistive Technology (FELAT) curriculum was developed as a needs-based, community educational program provided through a state Cooperative Extension Service. The overall goal for participants was to raise awareness of assistive technology. Program evaluation included a postassessment and subsequent interview to…

  19. A Journal-Club-Based Class that Promotes Active and Cooperative Learning of Biology

    ERIC Educational Resources Information Center

    Kitazono, Ana A.

    2010-01-01

    A journal-club-based class has been developed to promote active and cooperative learning and expose seniors in biochemistry and cellular molecular biology to recent research in the field. Besides giving oral presentations, students also write three papers: one discussing an article of their own choosing and two, discussing articles presented by…

  20. Inquiry and Groups: Student Interactions in Cooperative Inquiry-Based Science

    ERIC Educational Resources Information Center

    Woods-McConney, Amanda; Wosnitza, Marold; Sturrock, Keryn L.

    2016-01-01

    Science education research has recommended cooperative inquiry based science in the primary science context for more than two decades but after more than 20 years, student achievement in science has not substantially improved. This study, through direct observation and analysis, investigated content-related student interactions in an authentic…

  1. Inquiry and Groups: Student Interactions in Cooperative Inquiry-Based Science

    ERIC Educational Resources Information Center

    Woods-McConney, Amanda; Wosnitza, Marold; Sturrock, Keryn L.

    2016-01-01

    Science education research has recommended cooperative inquiry based science in the primary science context for more than two decades but after more than 20 years, student achievement in science has not substantially improved. This study, through direct observation and analysis, investigated content-related student interactions in an authentic…

  2. Optimal Base Station Density of Dense Network: From the Viewpoint of Interference and Load

    PubMed Central

    Feng, Zhiyong

    2017-01-01

    Network densification is attracting increasing attention recently due to its ability to improve network capacity by spatial reuse and relieve congestion by offloading. However, excessive densification and aggressive offloading can also cause the degradation of network performance due to problems of interference and load. In this paper, with consideration of load issues, we study the optimal base station density that maximizes the throughput of the network. The expected link rate and the utilization ratio of the contention-based channel are derived as the functions of base station density using the Poisson Point Process (PPP) and Markov Chain. They reveal the rules of deployment. Based on these results, we obtain the throughput of the network and indicate the optimal deployment density under different network conditions. Extensive simulations are conducted to validate our analysis and show the substantial performance gain obtained by the proposed deployment scheme. These results can provide guidance for the network densification. PMID:28891997

  3. Frequency analysis of extreme events based on precipitation station data over southeastern Brazil

    NASA Astrophysics Data System (ADS)

    Zilli, M. T.; Carvalho, L. V.

    2013-12-01

    The southeastern coast (SE) of Brazil is among the most densely populated areas of eastern South America with population largely concentrated in urban centers. Due to complex terrain and chaotic urbanization, this region is subject to a variety of natural disasters, including but not limited to floods and landslides that frequently occur during the austral summer (September to March). The South American Monsoon System (SAMS) and the South Atlantic Convergence zone (SACZ) are the most important climatic features that affect precipitation regimes in SE Brazil during the Austral summer. Previous studies have shown an overall increasing trend in daily precipitation and consequently in extreme events in SE Brazil. Future scenarios of climate change seem to indicate that SAMS daily precipitation will likely continue to increase throughout the 21st century. However, the rainfall response to the predicted warming is heterogeneous, and there is large uncertainty in the projected rainfall change and corresponding regional-to-local impacts. Some observational studies have demonstrated a positive trend in the frequency of extreme events in particular locations. Nevertheless, these analyses either focus on one single station or investigate relatively short periods. This study further investigates interannual to multiannual variations and changes in the frequency of daily extreme precipitation events in SE Brazil using long time series from a set of rain gauges stations. The analyzed rain gauge stations are located along the coastal area of SE Brazil (between 18°S and 25°S) and have at least 74 years of daily data, with less than 5% missing. The period of analysis varies slightly from station to station, but roughly all stations have data between 1930 and 2012. The analysis of the frequency of extreme events is based on the Peaks-over-Threshold (POT) approach, which follows a General Pareto Distribution (GPD), under the independent identically distributed assumption

  4. Space-based radio telescopes and an orbiting deep-space relay station

    NASA Technical Reports Server (NTRS)

    Powell, R. V.

    1979-01-01

    Foremost among the candidates for early utilization of the Shuttle-launched self-deployable structures are the space-based radio telescopes. Several space-based telescopes are examined including an orbiting VLBI terminal, an orbiting submillimeter telescope, and a large ambient deployable IR telescope. Particular consideration is given to the high-gain Orbiting Deep-Space Relay Station for communication with deep-space probes. Details of deployable antenna technology are discussed.

  5. Space Station

    NASA Image and Video Library

    1969-01-01

    This picture illustrates a concept of a 33-Foot-Diameter Space Station Leading to a Space Base. In-house work of the Marshall Space Flight Center, as well as a Phase B contract with the McDornel Douglas Astronautics Company, resulted in a preliminary design for a space station in 1969 and l970. The Marshall-McDonnel Douglas approach envisioned the use of two common modules as the core configuration of a 12-man space station. Each common module was 33 feet in diameter and 40 feet in length and provided the building blocks, not only for the space station, but also for a 50-man space base. Coupled together, the two modules would form a four-deck facility: two decks for laboratories and two decks for operations and living quarters. Zero-gravity would be the normal mode of operation, although the station would have an artificial gravity capability. This general-purpose orbital facility was to provide wide-ranging research capabilities. The design of the facility was driven by the need to accommodate a broad spectrum of activities in support of astronomy, astrophysics, aerospace medicine, biology, materials processing, space physics, and space manufacturing. To serve the needs of Earth observations, the station was to be placed in a 242-nautical-mile orbit at a 55-degree inclination. An Intermediate-21 vehicle (comprised of Saturn S-IC and S-II stages) would have launched the station in 1977.

  6. Distributed Cooperation Solution Method of Complex System Based on MAS

    NASA Astrophysics Data System (ADS)

    Weijin, Jiang; Yuhui, Xu

    To adapt the model in reconfiguring fault diagnosing to dynamic environment and the needs of solving the tasks of complex system fully, the paper introduced multi-Agent and related technology to the complicated fault diagnosis, an integrated intelligent control system is studied in this paper. Based on the thought of the structure of diagnostic decision and hierarchy in modeling, based on multi-layer decomposition strategy of diagnosis task, a multi-agent synchronous diagnosis federation integrated different knowledge expression modes and inference mechanisms are presented, the functions of management agent, diagnosis agent and decision agent are analyzed, the organization and evolution of agents in the system are proposed, and the corresponding conflict resolution algorithm in given, Layered structure of abstract agent with public attributes is build. System architecture is realized based on MAS distributed layered blackboard. The real world application shows that the proposed control structure successfully solves the fault diagnose problem of the complex plant, and the special advantage in the distributed domain.

  7. Space Station

    NASA Image and Video Library

    1991-01-01

    This artist's concept depicts the Space Station Freedom as it would look orbiting the Earth, illustrated by Marshall Space Flight Center artist, Tom Buzbee. Scheduled to be completed in late 1999, this smaller configuration of the Space Station featured a horizontal truss structure that supported U.S., European, and Japanese Laboratory Modules; the U.S. Habitation Module; and three sets of solar arrays. The Space Station Freedom was an international, permanently marned, orbiting base to be assembled in orbit by a series of Space Shuttle missions that were to begin in the mid-1990's.

  8. Space Station

    NASA Image and Video Library

    1991-01-01

    This artist's concept depicts the Space Station Freedom as it would look orbiting the Earth; illustrated by Marshall Space Flight Center artist, Tom Buzbee. Scheduled to be completed in late 1999, this smaller configuration of the Space Station features a horizontal truss structure that supported U.S., European, and Japanese Laboratory Modules; the U.S. Habitation Module; and three sets of solar arrays. The Space Station Freedom was an international, permanently marned, orbiting base to be assembled in orbit by a series of Space Shuttle missions that were to begin in the mid-1990's.

  9. Cooperative Networks

    DTIC Science & Technology

    2009-02-23

    than the traditional direct transmission and full cooperation schemes. B. OFDM-Based Cooperation Relay and Subchannel Assignment and Combining We... subchannel assignment and combining schemes. Based on the amount of CSI, resources, such as subchannels , can be allocated to relays to improve the end-to-end...relay node uses the same subchannel to relay the information transmitted by the source node. To further improve the performance gain, subchannel

  10. Mining Learning Social Networks for Cooperative Learning with Appropriate Learning Partners in a Problem-Based Learning Environment

    ERIC Educational Resources Information Center

    Chen, Chih-Ming; Chang, Chia-Cheng

    2014-01-01

    Many studies have identified web-based cooperative learning as an increasingly popular educational paradigm with potential to increase learner satisfaction and interactions. However, peer-to-peer interaction often suffers barriers owing to a failure to explore useful social interaction information in web-based cooperative learning environments.…

  11. The Effects of Inquiry-Based Computer Simulation with Cooperative Learning on Scientific Thinking and Conceptual Understanding of Gas Laws

    ERIC Educational Resources Information Center

    Abdullah, Sopiah; Shariff, Adilah

    2008-01-01

    The purpose of the study was to investigate the effects of inquiry-based computer simulation with heterogeneous-ability cooperative learning (HACL) and inquiry-based computer simulation with friendship cooperative learning (FCL) on (a) scientific reasoning (SR) and (b) conceptual understanding (CU) among Form Four students in Malaysian Smart…

  12. The Effects of Inquiry-Based Computer Simulation with Cooperative Learning on Scientific Thinking and Conceptual Understanding of Gas Laws

    ERIC Educational Resources Information Center

    Abdullah, Sopiah; Shariff, Adilah

    2008-01-01

    The purpose of the study was to investigate the effects of inquiry-based computer simulation with heterogeneous-ability cooperative learning (HACL) and inquiry-based computer simulation with friendship cooperative learning (FCL) on (a) scientific reasoning (SR) and (b) conceptual understanding (CU) among Form Four students in Malaysian Smart…

  13. Mining Learning Social Networks for Cooperative Learning with Appropriate Learning Partners in a Problem-Based Learning Environment

    ERIC Educational Resources Information Center

    Chen, Chih-Ming; Chang, Chia-Cheng

    2014-01-01

    Many studies have identified web-based cooperative learning as an increasingly popular educational paradigm with potential to increase learner satisfaction and interactions. However, peer-to-peer interaction often suffers barriers owing to a failure to explore useful social interaction information in web-based cooperative learning environments.…

  14. Knowledge-based vision for space station object motion detection, recognition, and tracking

    NASA Technical Reports Server (NTRS)

    Symosek, P.; Panda, D.; Yalamanchili, S.; Wehner, W., III

    1987-01-01

    Computer vision, especially color image analysis and understanding, has much to offer in the area of the automation of Space Station tasks such as construction, satellite servicing, rendezvous and proximity operations, inspection, experiment monitoring, data management and training. Knowledge-based techniques improve the performance of vision algorithms for unstructured environments because of their ability to deal with imprecise a priori information or inaccurately estimated feature data and still produce useful results. Conventional techniques using statistical and purely model-based approaches lack flexibility in dealing with the variabilities anticipated in the unstructured viewing environment of space. Algorithms developed under NASA sponsorship for Space Station applications to demonstrate the value of a hypothesized architecture for a Video Image Processor (VIP) are presented. Approaches to the enhancement of the performance of these algorithms with knowledge-based techniques and the potential for deployment of highly-parallel multi-processor systems for these algorithms are discussed.

  15. 33 CFR 334.746 - U.S. Coast Guard, Destin Station at Eglin Air Force Base, Fla.; restricted area.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false U.S. Coast Guard, Destin Station at Eglin Air Force Base, Fla.; restricted area. 334.746 Section 334.746 Navigation and Navigable... REGULATIONS § 334.746 U.S. Coast Guard, Destin Station at Eglin Air Force Base, Fla.; restricted area. (a) The...

  16. Automated guidance algorithms for a space station-based crew escape vehicle.

    PubMed

    Flanary, R; Hammen, D G; Ito, D; Rabalais, B W; Rishikof, B H; Siebold, K H

    2003-04-01

    An escape vehicle was designed to provide an emergency evacuation for crew members living on a space station. For maximum escape capability, the escape vehicle needs to have the ability to safely evacuate a station in a contingency scenario such as an uncontrolled (e.g., tumbling) station. This emergency escape sequence will typically be divided into three events: The first separation event (SEP1), the navigation reconstruction event, and the second separation event (SEP2). SEP1 is responsible for taking the spacecraft from its docking port to a distance greater than the maximum radius of the rotating station. The navigation reconstruction event takes place prior to the SEP2 event and establishes the orbital state to within the tolerance limits necessary for SEP2. The SEP2 event calculates and performs an avoidance burn to prevent station recontact during the next several orbits. This paper presents the tools and results for the whole separation sequence with an emphasis on the two separation events. The first challenge includes collision avoidance during the escape sequence while the station is in an uncontrolled rotational state, with rotation rates of up to 2 degrees per second. The task of avoiding a collision may require the use of the Vehicle's de-orbit propulsion system for maximum thrust and minimum dwell time within the vicinity of the station vicinity. The thrust of the propulsion system is in a single direction, and can be controlled only by the attitude of the spacecraft. Escape algorithms based on a look-up table or analytical guidance can be implemented since the rotation rate and the angular momentum vector can be sensed onboard and a-priori knowledge of the position and relative orientation are available. In addition, crew intervention has been provided for in the event of unforeseen obstacles in the escape path. The purpose of the SEP2 burn is to avoid re-contact with the station over an extended period of time. Performing this maneuver requires

  17. A Cooperative Approach to Virtual Machine Based Fault Injection

    SciTech Connect

    Naughton III, Thomas J; Engelmann, Christian; Vallee, Geoffroy R; Aderholdt, William Ferrol; Scott, Stephen L

    2017-01-01

    Resilience investigations often employ fault injection (FI) tools to study the effects of simulated errors on a target system. It is important to keep the target system under test (SUT) isolated from the controlling environment in order to maintain control of the experiement. Virtual machines (VMs) have been used to aid these investigations due to the strong isolation properties of system-level virtualization. A key challenge in fault injection tools is to gain proper insight and context about the SUT. In VM-based FI tools, this challenge of target con- text is increased due to the separation between host and guest (VM). We discuss an approach to VM-based FI that leverages virtual machine introspection (VMI) methods to gain insight into the target s context running within the VM. The key to this environment is the ability to provide basic information to the FI system that can be used to create a map of the target environment. We describe a proof- of-concept implementation and a demonstration of its use to introduce simulated soft errors into an iterative solver benchmark running in user-space of a guest VM.

  18. Worst-case-based robust beamforming for wireless cooperative networks

    NASA Astrophysics Data System (ADS)

    Zhang, Li; Chen, Haihua; He, Ming

    2014-12-01

    It is known that distributed beamforming techniques can improve the performance of relay networks by using channel state information (CSI). In practical applications, there exist unavoidably estimation errors of the CSI, which results in outage of quality of service (QoS) or overconsumption of transmit power. In this paper, we propose two worst-case-based distributed beamforming techniques that are robust to the channel estimation errors. In the worst-case-based approaches, the worst case in a set that includes the actual case is optimized. Therefore, the performance of the actual case can be guaranteed. In our first approach, the maximal total relay transmit power in the set is minimized subject to the QoS constraint. This distributed beamforming problem can be approximately solved using second-order cone programming (SOCP). In our second method, the worst QoS in the set is maximized subject to the constraints of individual relay transmit powers. It is shown that the resultant problem can be approximately formulated as a quasi-convex problem and can be solved by using a bisection search method. Simulation results show that the proposed beamforming techniques are robust to the CSI errors and there is no outage of QoS or power in the proposed methods.

  19. On cooperative and efficient overlay network evolution based on a group selection pattern.

    PubMed

    Nakao, Akihiro; Wang, Yufeng

    2010-04-01

    In overlay networks, the interplay between network structure and dynamics remains largely unexplored. In this paper, we study dynamic coevolution between individual rational strategies (cooperative or defect) and the overlay network structure, that is, the interaction between peer's local rational behaviors and the emergence of the whole network structure. We propose an evolutionary game theory (EGT)-based overlay topology evolution scheme to drive a given overlay into the small-world structure (high global network efficiency and average clustering coefficient). Our contributions are the following threefold: From the viewpoint of peers' local interactions, we explicitly consider the peer's rational behavior and introduce a link-formation game to characterize the social dilemma of forming links in an overlay network. Furthermore, in the evolutionary link-formation phase, we adopt a simple economic process: Each peer keeps one link to a cooperative neighbor in its neighborhood, which can slightly speed up the convergence of cooperation and increase network efficiency; from the viewpoint of the whole network structure, our simulation results show that the EGT-based scheme can drive an arbitrary overlay network into a fully cooperative and efficient small-world structure. Moreover, we compare our scheme with a search-based economic model of network formation and illustrate that our scheme can achieve the experimental and analytical results in the latter model. In addition, we also graphically illustrate the final overlay network structure; finally, based on the group selection model and evolutionary set theory, we theoretically obtain the approximate threshold of cost and draw the conclusion that the small value of the average degree and the large number of the total peers in an overlay network facilitate the evolution of cooperation.

  20. Amplify-and-Forward Cooperative Diversity for Green UWB-Based WBSNs

    PubMed Central

    2013-01-01

    This paper proposes a novel green cooperative diversity technique based on suboptimal template-based ultra-wideband (UWB) wireless body sensor networks (WBSNs) using amplify-and-forward (AF) relays. In addition, it analyzes the bit-error-rate (BER) performance of the proposed nodes. The analysis is based on the moment-generating function (MGF) of the total signal-to-noise ratio (SNR) at the destination. It also provides an approximate value for the total SNR. The analysis studies the performance of equally correlated binary pulse position modulation (EC-BPPM) assuming the sinusoidal and square suboptimal template pulses. Numerical results are provided for the performance evaluation of optimal and suboptimal template-based nodes with and without relay cooperation. Results show that one relay node provides ~23 dB performance enhancement at 1e − 3 BER, which mitigates the effect of the nondesirable non-line-of-sight (NLOS) links in WBSNs. PMID:24307880

  1. Amplify-and-forward cooperative diversity for green UWB-based WBSNs.

    PubMed

    Shaban, Heba; Abou El-Nasr, Mohamad

    2013-01-01

    This paper proposes a novel green cooperative diversity technique based on suboptimal template-based ultra-wideband (UWB) wireless body sensor networks (WBSNs) using amplify-and-forward (AF) relays. In addition, it analyzes the bit-error-rate (BER) performance of the proposed nodes. The analysis is based on the moment-generating function (MGF) of the total signal-to-noise ratio (SNR) at the destination. It also provides an approximate value for the total SNR. The analysis studies the performance of equally correlated binary pulse position modulation (EC-BPPM) assuming the sinusoidal and square suboptimal template pulses. Numerical results are provided for the performance evaluation of optimal and suboptimal template-based nodes with and without relay cooperation. Results show that one relay node provides ~23 dB performance enhancement at 1e - 3 BER, which mitigates the effect of the nondesirable non-line-of-sight (NLOS) links in WBSNs.

  2. Statistical analysis of electromagnetic radiation measurements in the vicinity of GSM/UMTS base station antenna masts.

    PubMed

    Koprivica, Mladen; Neskovic, Natasa; Neskovic, Aleksandar; Paunovic, George

    2014-01-01

    As a result of dense installations of public mobile base station, additional electromagnetic radiation occurs in the living environment. In order to determine the level of radio-frequency radiation generated by base stations, extensive electromagnetic field strength measurements were carried out for 664 base station locations. Base station locations were classified into three categories: indoor, masts and locations with installations on buildings. Having in mind the large percentage (47 %) of sites with antenna masts, a detailed analysis of this location category was performed, and the measurement results were presented. It was concluded that the total electric field strength in the vicinity of base station antenna masts in no case exceeded 10 V m(-1), which is quite below the International Commission on Non-Ionizing Radiation Protection reference levels. At horizontal distances >50 m from the mast bottom, the median and maximum values were <1 and 2 V m(-1), respectively.

  3. Cooperation in memory-based prisoner's dilemma game on interdependent networks

    NASA Astrophysics Data System (ADS)

    Luo, Chao; Zhang, Xiaolin; Liu, Hong; Shao, Rui

    2016-05-01

    Memory or so-called experience normally plays the important role to guide the human behaviors in real world, that is essential for rational decisions made by individuals. Hence, when the evolutionary behaviors of players with bounded rationality are investigated, it is reasonable to make an assumption that players in system are with limited memory. Besides, in order to unravel the intricate variability of complex systems in real world and make a highly integrative understanding of their dynamics, in recent years, interdependent networks as a comprehensive network structure have obtained more attention in this community. In this article, the evolution of cooperation in memory-based prisoner's dilemma game (PDG) on interdependent networks composed by two coupled square lattices is studied. Herein, all or part of players are endowed with finite memory ability, and we focus on the mutual influence of memory effect and interdependent network reciprocity on cooperation of spatial PDG. We show that the density of cooperation can be significantly promoted within an optimal region of memory length and interdependent strength. Furthermore, distinguished by whether having memory ability/external links or not, each kind of players on networks would have distinct evolutionary behaviors. Our work could be helpful to understand the emergence and maintenance of cooperation under the evolution of memory-based players on interdependent networks.

  4. A strategic conflict avoidance approach based on cooperative coevolutionary with the dynamic grouping strategy

    NASA Astrophysics Data System (ADS)

    Guan, Xiangmin; Zhang, Xuejun; Wei, Jian; Hwang, Inseok; Zhu, Yanbo; Cai, Kaiquan

    2016-07-01

    Conflict avoidance plays a crucial role in guaranteeing the safety and efficiency of the air traffic management system. Recently, the strategic conflict avoidance (SCA) problem has attracted more and more attention. Taking into consideration the large-scale flight planning in a global view, SCA can be formulated as a large-scale combinatorial optimisation problem with complex constraints and tight couplings between variables, which is difficult to solve. In this paper, an SCA approach based on the cooperative coevolution algorithm combined with a new decomposition strategy is proposed to prevent the premature convergence and improve the search capability. The flights are divided into several groups using the new grouping strategy, referred to as the dynamic grouping strategy, which takes full advantage of the prior knowledge of the problem to better deal with the tight couplings among flights through maximising the chance of putting flights with conflicts in the same group, compared with existing grouping strategies. Then, a tuned genetic algorithm (GA) is applied to different groups simultaneously to resolve conflicts. Finally, the high-quality solutions are obtained through cooperation between different groups based on cooperative coevolution. Simulation results using real flight data from the China air route network and daily flight plans demonstrate that the proposed algorithm can reduce the number of conflicts and the average delay effectively, outperforming existing approaches including GAs, the memetic algorithm, and the cooperative coevolution algorithms with different well-known grouping strategies.

  5. A NASA/RAE cooperation in the development of a real-time knowledge based autopilot

    NASA Technical Reports Server (NTRS)

    Daysh, Colin; Corbin, Malcolm; Butler, Geoff; Duke, Eugene L.; Belle, Steven D.; Brumbaugh, Randal W.

    1991-01-01

    As part of a US/UK cooperative aeronautical research program, a joint activity between NASA-Ames and the Royal Aerospace Establishment on Knowledge Based Systems (KBS) was established. This joint activity is concerned with tools and techniques for the implementation and validation of real-time KBS. The proposed next stage of the research is described, in which some of the problems of implementing and validating a Knowledge Based Autopilot (KBAP) for a generic high performance aircraft will be studied.

  6. Measuring sustainability based upon various perspectives: a case study of a hill station in Southeast Asia.

    PubMed

    Estoque, Ronald C; Murayama, Yuji

    2014-11-01

    A hill station is a town or city situated in mountain regions in the tropics founded during the western colonization in the nineteenth and early twentieth centuries. Hill stations have moderate temperatures, and are known for their relatively good natural environments, which generate valuable ecosystem services that benefit the local population. However, rapid urbanization threatens the sustainability of these areas. This study evaluates the sustainability of the urbanization process of Baguio City, a hill station city in Southeast Asia and the summer capital of the Philippines, by determining the relationship between its velocity of urbanization and velocity of urban sustainability based upon various perspectives. From an equal weight perspective (of the triple bottom line of sustainability components, namely environmental, social, and economic) and a pro-economic perspective, the results revealed that the urbanization of Baguio City has been moving toward a "sustainable urbanization." However, from the environmental and eco-sustainable human development perspectives, the results indicated that it has been moving toward an "unsustainable urbanization." The paper discusses the implications of the findings for the planning of sustainable development for Baguio City, including some critical challenges in sustainability assessment and the applicability of the framework used for future sustainability assessments of the other hill stations in Southeast Asia.

  7. Lambda Station: On-demand flow based routing for data intensive Grid applications over multitopology networks

    SciTech Connect

    Bobyshev, A.; Crawford, M.; DeMar, P.; Grigaliunas, V.; Grigoriev, M.; Moibenko, A.; Petravick, D.; Rechenmacher, R.; Newman, H.; Bunn, J.; Van Lingen, F.; Nae, D.; Ravot, S.; Steenberg, C.; Su, X.; Thomas, M.; Xia, Y.; /Caltech

    2006-08-01

    Lambda Station is an ongoing project of Fermi National Accelerator Laboratory and the California Institute of Technology. The goal of this project is to design, develop and deploy network services for path selection, admission control and flow based forwarding of traffic among data-intensive Grid applications such as are used in High Energy Physics and other communities. Lambda Station deals with the last-mile problem in local area networks, connecting production clusters through a rich array of wide area networks. Selective forwarding of traffic is controlled dynamically at the demand of applications. This paper introduces the motivation of this project, design principles and current status. Integration of Lambda Station client API with the essential Grid middleware such as the dCache/SRM Storage Resource Manager is also described. Finally, the results of applying Lambda Station services to development and production clusters at Fermilab and Caltech over advanced networks such as DOE's UltraScience Net and NSF's UltraLight is covered.

  8. Analyzing mobile WiMAX base station deployment under different frequency planning strategies

    NASA Astrophysics Data System (ADS)

    Salman, M. K.; Ahmad, R. B.; Ali, Ziad G.; Aldhaibani, Jaafar A.; Fayadh, Rashid A.

    2015-05-01

    The frequency spectrum is a precious resource and scarce in the communication markets. Therefore, different techniques are adopted to utilize the available spectrum in deploying WiMAX base stations (BS) in cellular networks. In this paper several types of frequency planning techniques are illustrated, and a comprehensive comparative study between conventional frequency reuse of 1 (FR of 1) and fractional frequency reuse (FFR) is presented. These techniques are widely used in network deployment, because they employ universal frequency (using all the available bandwidth) in their base station installation/configuration within network system. This paper presents a network model of 19 base stations in order to be employed in the comparison of the aforesaid frequency planning techniques. Users are randomly distributed within base stations, users' resource mapping and their burst profile selection are based on the measured signal to interference plus-noise ratio (SINR). Simulation results reveal that the FFR has advantages over the conventional FR of 1 in various metrics. 98 % of downlink resources (slots) are exploited when FFR is applied, whilst it is 81 % at FR of 1. Data rate of FFR has been increased to 10.6 Mbps, while it is 7.98 Mbps at FR of 1. The spectral efficiency is better enhanced (1.072 bps/Hz) at FR of 1 than FFR (0.808 bps/Hz), since FR of 1 exploits all the Bandwidth. The subcarrier efficiency shows how many data bits that can be carried by subcarriers under different frequency planning techniques, the system can carry more data bits under FFR (2.40 bit/subcarrier) than FR of 1 (1.998 bit/subcarrier). This study confirms that FFR can perform better than conventional frequency planning (FR of 1) which made it a strong candidate for WiMAX BS deployment in cellular networks.

  9. Design of Radio Frequency Link in Automatic Test System for Multimode Mobile Communication Base Station

    NASA Astrophysics Data System (ADS)

    Zhang, Weipeng

    2015-12-01

    A modularized design for the radio frequency (RF) link in automatic test system of multimode mobile communication base station is presented, considering also the characteristics of wireless communication indices and composition of signals of base stations. The test link is divided into general module, time division duplex (TDD) module, module of spurious noise filter, module of downlink intermodulation, module of uplink intermodulation and uplink block module. The composition of modules and link functions are defined, and the interfaces of the general module and the module of spurious noise filter are described. Finally, the estimated gain budget of the test link is presented. It is verified by experiments that the system is reliable and the test efficiency is improved.

  10. Laser based bi-directional Gbit ground links with the Tesat transportable adaptive optical ground station

    NASA Astrophysics Data System (ADS)

    Heine, Frank; Saucke, Karen; Troendle, Daniel; Motzigemba, Matthias; Bischl, Hermann; Elser, Dominique; Marquardt, Christoph; Henninger, Hennes; Meyer, Rolf; Richter, Ines; Sodnik, Zoran

    2017-02-01

    Optical ground stations can be an alternative to radio frequency based transmit (forward) and receive (return) systems for data relay services and other applications including direct to earth optical communications from low earth orbit spacecrafts, deep space receivers, space based quantum key distribution systems and Tbps capacity feeder links to geostationary spacecrafts. The Tesat Transportable Adaptive Optical Ground Station is operational since September 2015 at the European Space Agency site in Tenerife, Spain.. This paper reports about the results of the 2016 experimental campaigns including the characterization of the optical channel from Tenerife for an optimized coding scheme, the performance of the T-AOGS under different atmospheric conditions and the first successful measurements of the suitability of the Alphasat LCT optical downlink performance for future continuous variable quantum key distribution systems.

  11. Space station software reliability analysis based on failures observed during testing at the multisystem integration facility

    NASA Technical Reports Server (NTRS)

    Tamayo, Tak Chai

    1987-01-01

    Quality of software not only is vital to the successful operation of the space station, it is also an important factor in establishing testing requirements, time needed for software verification and integration as well as launching schedules for the space station. Defense of management decisions can be greatly strengthened by combining engineering judgments with statistical analysis. Unlike hardware, software has the characteristics of no wearout and costly redundancies, thus making traditional statistical analysis not suitable in evaluating reliability of software. A statistical model was developed to provide a representation of the number as well as types of failures occur during software testing and verification. From this model, quantitative measure of software reliability based on failure history during testing are derived. Criteria to terminate testing based on reliability objectives and methods to estimate the expected number of fixings required are also presented.

  12. Implicit attitudes toward nuclear power and mobile phone base stations: support for the affect heuristic.

    PubMed

    Siegrist, Michael; Keller, Carmen; Cousin, Marie-Eve

    2006-08-01

    The implicit association test (IAT) measures automatic associations. In the present research, the IAT was adapted to measure implicit attitudes toward technological hazards. In Study 1, implicit and explicit attitudes toward nuclear power were examined. Implicit measures (i.e., the IAT) revealed negative attitudes toward nuclear power that were not detected by explicit measures (i.e., a questionnaire). In Study 2, implicit attitudes toward EMF (electro-magnetic field) hazards were examined. Results showed that cell phone base stations and power lines are judged to be similarly risky and, further, that base stations are more closely related to risk concepts than home appliances are. No differences between experts and lay people were observed. Results of the present studies are in line with the affect heuristic proposed by Slovic and colleagues. Affect seems to be an important factor in risk perception.

  13. Final Environmental Assessment of Mosquito Control at Joint Base Charleston - Weapons Station

    DTIC Science & Technology

    2011-04-01

    the proposed action, Joint Base Charleston (JB CHS) would manage mosquito populations on two parcels known as the Naval Weapons Station (NWS) spoil...predators for mosquitoes living on the dredge spoil areas. Large populations of mosquitoes restrict outdoor work and effectiveness of personnel...The human and mosquito populations frequently interface and, if improperly managed, would result in the spread of serious diseases. Large mosquito

  14. A pressure control method for emulsion pump station based on Elman neural network.

    PubMed

    Tan, Chao; Qi, Nan; Zhou, Xin; Liu, Xinhua; Yao, Xingang; Wang, Zhongbin; Si, Lei

    2015-01-01

    In order to realize pressure control of emulsion pump station which is key equipment of coal mine in the safety production, the control requirements were analyzed and a pressure control method based on Elman neural network was proposed. The key techniques such as system framework, pressure prediction model, pressure control model, and the flowchart of proposed approach were presented. Finally, a simulation example was carried out and comparison results indicated that the proposed approach was feasible and efficient and outperformed others.

  15. Data Reduction and Control Software for Meteor Observing Stations Based on CCD Video Systems

    NASA Technical Reports Server (NTRS)

    Madiedo, J. M.; Trigo-Rodriguez, J. M.; Lyytinen, E.

    2011-01-01

    The SPanish Meteor Network (SPMN) is performing a continuous monitoring of meteor activity over Spain and neighbouring countries. The huge amount of data obtained by the 25 video observing stations that this network is currently operating made it necessary to develop new software packages to accomplish some tasks, such as data reduction and remote operation of autonomous systems based on high-sensitivity CCD video devices. The main characteristics of this software are described here.

  16. National Training Center, Joint Readiness Training Center, and Home Station-Based Program Products

    DTIC Science & Technology

    1987-04-01

    Readiness Training Center (JRTC), Home Station Training, and the Combined Arms Training Activity (CATA) Lessons Learned Program are described below...effectiveness in obtaining information needed for the lessons learned program . Description of Key Products: Leader Performance: o Impact of platoon...of the improved NTC. data base, the NTC feedback system, and support of the Army’s lessons learned program . Measures for critical task performance

  17. A Pressure Control Method for Emulsion Pump Station Based on Elman Neural Network

    PubMed Central

    Tan, Chao; Qi, Nan; Yao, Xingang; Wang, Zhongbin; Si, Lei

    2015-01-01

    In order to realize pressure control of emulsion pump station which is key equipment of coal mine in the safety production, the control requirements were analyzed and a pressure control method based on Elman neural network was proposed. The key techniques such as system framework, pressure prediction model, pressure control model, and the flowchart of proposed approach were presented. Finally, a simulation example was carried out and comparison results indicated that the proposed approach was feasible and efficient and outperformed others. PMID:25861253

  18. The effect of link-based topological changes and recoveries on the robustness of cooperation on scale-free networks

    NASA Astrophysics Data System (ADS)

    Wang, Shuai; Liu, Jing

    2016-07-01

    The emergence of cooperation is one of the key metaphors behind many social disciplines and phenomena. Existing studies show that intentional attacks on nodes damage the robustness of cooperation distinctly, and the heterogeneity among nodes promotes the emergence of cooperation. However, the impact of link-based attacks and the connectivity of networks on the cooperative mechanism is still unclear. In this paper, we focus on the effect of edge removal on the emergence of cooperation together with the connectivity of networks. The results show that malicious attacks evaluated by edge-degree are efficient to invade cooperators, and heterogeneous networks tend to perform poorly when attacks arise. Furthermore, we analyze the performance of several recovering strategies, and conclude that the connectivity is crucial to the recovery of functionality of whole networks.

  19. A reference station-based GNSS computing mode to support unified precise point positioning and real-time kinematic services

    NASA Astrophysics Data System (ADS)

    Feng, Yanming; Gu, Shengfeng; Shi, Chuang; Rizos, Chris

    2013-11-01

    Currently, the GNSS computing modes are of two classes: network-based data processing and user receiver-based processing. A GNSS reference receiver station essentially contributes raw measurement data in either the RINEX file format or as real-time data streams in the RTCM format. Very little computation is carried out by the reference station. The existing network-based processing modes, regardless of whether they are executed in real-time or post-processed modes, are centralised or sequential. This paper describes a distributed GNSS computing framework that incorporates three GNSS modes: reference station-based, user receiver-based and network-based data processing. Raw data streams from each GNSS reference receiver station are processed in a distributed manner, i.e., either at the station itself or at a hosting data server/processor, to generate station-based solutions, or reference receiver-specific parameters. These may include precise receiver clock, zenith tropospheric delay, differential code biases, ambiguity parameters, ionospheric delays, as well as line-of-sight information such as azimuth and elevation angles. Covariance information for estimated parameters may also be optionally provided. In such a mode the nearby precise point positioning (PPP) or real-time kinematic (RTK) users can directly use the corrections from all or some of the stations for real-time precise positioning via a data server. At the user receiver, PPP and RTK techniques are unified under the same observation models, and the distinction is how the user receiver software deals with corrections from the reference station solutions and the ambiguity estimation in the observation equations. Numerical tests demonstrate good convergence behaviour for differential code bias and ambiguity estimates derived individually with single reference stations. With station-based solutions from three reference stations within distances of 22-103 km the user receiver positioning results, with various

  20. Exploring the cooperative regimes in an agent-based model: indirect reciprocity vs. selfish incentives

    NASA Astrophysics Data System (ADS)

    Fort, H.

    2003-08-01

    The self-organization in cooperative regimes in a simple mean-field version of a model based on “selfish” agents which play the Prisoner's Dilemma (PD) game is studied. The agents have no memory and use strategies not based on direct reciprocity nor “tags”. Two variables are assigned to each agent k at time t, measuring its capital C( k; t) and its probability of cooperation p( k; t). At each time step t a pair of agents interact by playing the PD game. These two agents update their probability of cooperation p( k; t) as follows: they compare the profits they made in this interaction δC( k; t) with an estimator ε( k; t) and, if δC( k; t)⩾ ε( k; t), agent i increases its p( k; t) while if δC( k; t)< ε( k; t) the agent decreases p( k; t). The 4!=24 different cases produced by permuting the four Prisoner's Dilemma canonical payoffs 3, 0, 1, and 5-corresponding, respectively, to R (reward), S (sucker's payoff), T (temptation to defect) and P (punishment)-are analyzed. It turns out that for all these 24 possibilities, after a transient, the system self-organizes into a stationary state with average equilibrium probability of cooperation p¯∞= constant>0 . Depending on the payoff matrix, there are different equilibrium states characterized by their average probability of cooperation and average equilibrium per capita income ( p¯∞, δC¯∞) .

  1. The Evolution of Cooperation in Managed Groundwater Systems: An Agent-Based Modelling Approach

    NASA Astrophysics Data System (ADS)

    Castilla Rho, J. C.; Mariethoz, G.; Rojas, R. F.; Andersen, M. S.; Kelly, B. F.; Holley, C.

    2014-12-01

    Human interactions with groundwater systems often exhibit complex features that hinder the sustainable management of the resource. This leads to costly and persistent conflicts over groundwater at the catchment scale. One possible way to address these conflicts is by gaining a better understanding of how social and groundwater dynamics coevolve using agent-based models (ABM). Such models allow exploring 'bottom-up' solutions (i.e., self-organised governance systems), where the behaviour of individual agents (e.g., farmers) results in the emergence of mutual cooperation among groundwater users. There is significant empirical evidence indicating that this kind of 'bottom-up' approach may lead to more enduring and sustainable outcomes, compared to conventional 'top-down' strategies such as centralized control and water right schemes (Ostrom 1990). New modelling tools are needed to study these concepts systematically and efficiently. Our model uses a conceptual framework to study cooperation and the emergence of social norms as initially proposed by Axelrod (1986), which we adapted to groundwater management. We developed an ABM that integrates social mechanisms and the physics of subsurface flow. The model explicitly represents feedback between groundwater conditions and social dynamics, capturing the spatial structure of these interactions and the potential effects on cooperation levels in an agricultural setting. Using this model, we investigate a series of mechanisms that may trigger norms supporting cooperative strategies, which can be sustained and become stable over time. For example, farmers in a self-monitoring community can be more efficient at achieving the objective of sustainable groundwater use than government-imposed regulation. Our coupled model thus offers a platform for testing new schemes promoting cooperation and improved resource use, which can be used as a basis for policy design. Importantly, we hope to raise awareness of agent-based modelling as

  2. Assessment and comparison of total RF-EMF exposure in femtocell and macrocell base station scenarios.

    PubMed

    Aerts, Sam; Plets, David; Verloock, Leen; Martens, Luc; Joseph, Wout

    2014-12-01

    The indoor coverage of a mobile service can be drastically improved by deployment of an indoor femtocell base station (FBS). However, the impact of its proximity on the total exposure of the human body to radio-frequency (RF) electromagnetic fields (EMFs) is unknown. Using a framework designed for the combination of near-field and far-field exposure, the authors assessed and compared the RF-EMF exposure of a mobile-phone (MP) user that is either connected to an FBS or a conventional macrocell base station while in an office environment. It is found that, in average macrocell coverage and MP use-time conditions and for Universal Mobile Telecommunications System technology, the total exposure can be reduced by a factor of 20-40 by using an FBS, mostly due to the significant decrease in the output power of the MP. In general, the framework presented in this study can be used for any exposure scenario, featuring any number of technologies, base stations and/or access points, users and duration. © The Author 2013. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  3. Space Station

    NASA Image and Video Library

    1970-01-01

    This is an illustration of the Space Base concept. In-house work of the Marshall Space Flight Center, as well as a Phase B contract with the McDornel Douglas Astronautics Company, resulted in a preliminary design for a space station in 1969 and l970. The Marshall-McDonnel Douglas approach envisioned the use of two common modules as the core configuration of a 12-man space station. Each common module was 33 feet in diameter and 40 feet in length and provided the building blocks, not only for the space station, but also for a 50-man space base. Coupled together, the two modules would form a four-deck facility: two decks for laboratories and two decks for operations and living quarters. Zero-gravity would be the normal mode of operation, although the station would have an artificial-gravity capability. This general-purpose orbital facility was to provide wide-ranging research capabilities. The design of the facility was driven by the need to accommodate a broad spectrum of activities in support of astronomy, astrophysics, aerospace medicine, biology, materials processing, space physics, and space manufacturing. To serve the needs of Earth observations, the station was to be placed in a 242-nautical-mile orbit at a 55-degree inclination. An Intermediate-21 vehicle (comprised of Saturn S-IC and S-II stages) would have launched the station in 1977.

  4. Optimal periodic cooperative spectrum sensing based on weight fusion in cognitive radio networks.

    PubMed

    Liu, Xin; Jia, Min; Gu, Xuemai; Tan, Xuezhi

    2013-04-19

    The performance of cooperative spectrum sensing in cognitive radio (CR) networks depends on the sensing mode, the sensing time and the number of cooperative users. In order to improve the sensing performance and reduce the interference to the primary user (PU), a periodic cooperative spectrum sensing model based on weight fusion is proposed in this paper. Moreover, the sensing period, the sensing time and the searching time are optimized, respectively. Firstly the sensing period is optimized to improve the spectrum utilization and reduce the interference, then the joint optimization algorithm of the local sensing time and the number of cooperative users, is proposed to obtain the optimal sensing time for improving the throughput of the cognitive radio user (CRU) during each period, and finally the water-filling principle is applied to optimize the searching time in order to make the CRU find an idle channel within the shortest time. The simulation results show that compared with the previous algorithms, the optimal sensing period can improve the spectrum utilization of the CRU and decrease the interference to the PU significantly, the optimal sensing time can make the CRU achieve the largest throughput, and the optimal searching time can make the CRU find an idle channel with the least time.

  5. Agent Based Modeling of Collaboration and Work Practices Onboard the International Space Station

    NASA Technical Reports Server (NTRS)

    Acquisti, Alessandro; Sierhuis, Maarten; Clancey, William J.; Bradshaw, Jeffrey M.; Shaffo, Mike (Technical Monitor)

    2002-01-01

    The International Space Station is one the most complex projects ever, with numerous interdependent constraints affecting productivity and crew safety. This requires planning years before crew expeditions, and the use of sophisticated scheduling tools. Human work practices, however, are difficult to study and represent within traditional planning tools. We present an agent-based model and simulation of the activities and work practices of astronauts onboard the ISS based on an agent-oriented approach. The model represents 'a day in the life' of the ISS crew and is developed in Brahms, an agent-oriented, activity-based language used to model knowledge in situated action and learning in human activities.

  6. Backstepping-based cooperative and adaptive tracking control design for a group of underactuated AUVs in horizontal plan

    NASA Astrophysics Data System (ADS)

    Ghommam, Jawhar; Saad, Maarouf

    2014-05-01

    In this paper, we investigate new implementable cooperative adaptive backstepping controllers for a group of underactuated autonomous vehicles that are communicating with their local neighbours to track a time-varying virtual leader of which the relative position may only be available to a portion of the team members. At the kinematic cooperative control level of the autonomous underwater vehicle, the virtual cooperative controller is basically designed on a proportional and derivative consensus algorithm presented in Ren (2010), which involves velocity information from local neighbours. In this paper, we propose a new design algorithm based on singular perturbation theory that precludes the use of the neighbours' velocity information in the cooperative design. At the dynamic cooperative control level, calculation of the partial derivatives of some stabilising functions which in turn will contain velocity information from the local neighbours is required. To facilitate the implementation of the cooperative controllers, we propose a command filter approach technique to avoid analytic differentiation of the virtual cooperative control laws. We show how Lyapunov-based techniques and graph theory can be combined together to yield a robust cooperative controller where the uncertain dynamics of the cooperating vehicles and the constraints on the communication topology which contains a directed spanning tree are explicitly taken into account. Simulation results with a dynamic model of underactuated autonomous underwater vehicles moving on the horizontal plane are presented and discussed.

  7. Mobile phone base stations and early childhood cancers: case-control study.

    PubMed

    Elliott, Paul; Toledano, Mireille B; Bennett, J; Beale, L; de Hoogh, K; Best, N; Briggs, D J

    2010-06-22

    To investigate the risk of early childhood cancers associated with the mother's exposure to radiofrequency from and proximity to macrocell mobile phone base stations (masts) during pregnancy. Case-control study. Cancer registry and national birth register data in Great Britain. 1397 cases of cancer in children aged 0-4 from national cancer registry 1999-2001 and 5588 birth controls from national birth register, individually matched by sex and date of birth (four controls per case). Incidence of cancers of the brain and central nervous system, leukaemia, and non-Hodgkin's lymphomas, and all cancers combined, adjusted for small area measures of education level, socioeconomic deprivation, population density, and population mixing. Mean distance of registered address at birth from a macrocell base station, based on a national database of 76,890 base station antennas in 1996-2001, was similar for cases and controls (1107 (SD 1131) m v 1073 (SD 1130) m, P=0.31), as was total power output of base stations within 700 m of the address (2.89 (SD 5.9) kW v 3.00 (SD 6.0) kW, P=0.54) and modelled power density (-30.3 (SD 21.7) dBm v -29.7 (SD 21.5) dBm, P=0.41). For modelled power density at the address at birth, compared with the lowest exposure category the adjusted odds ratios were 1.01 (95% confidence interval 0.87 to 1.18) in the intermediate and 1.02 (0.88 to 1.20) in the highest exposure category for all cancers (P=0.79 for trend), 0.97 (0.69 to 1.37) and 0.76 (0.51 to 1.12), respectively, for brain and central nervous system cancers (P=0.33 for trend), and 1.16 (0.90 to 1.48) and 1.03 (0.79 to 1.34) for leukaemia and non-Hodgkin's lymphoma (P=0.51 for trend). There is no association between risk of early childhood cancers and estimates of the mother's exposure to mobile phone base stations during pregnancy.

  8. Comparison of student performance in cooperative learning and traditional lecture-based biochemistry classes.

    PubMed

    Anderson, William L; Mitchell, Steven M; Osgood, Marcy P

    2005-11-01

    Student performance in two different introductory biochemistry curricula are compared based on standardized testing of student content knowledge, problem-solving skills, and student opinions about the courses. One curriculum was used in four traditional, lecture-based classes (n = 381 students), whereas the second curriculum was used in two cooperative learning classes (n = 39 students). Students in the cooperative learning classes not only performed at a level above their peers in standardized testing of content knowledge and in critical thinking and problem-solving tasks (p < 0.05), but they also were more positive about their learning experience. The testing data are in contrast to much of the medical school literature on the performance of students in problem-based learning (PBL) curricula, which shows little effect of the curricular format on student exam scores. The reason for the improvement is undoubtedly multifactorial. We argue that the enhancement of student performance in this study is related to: 1) the use of peer educational assistants, 2) an authentic PBL format, and 3) the application of a multicontextual learning environment in the curricular design. Though educationally successful, the cooperative learning classes as described in this study were too resource intensive to continue; however, we are exploring incorporation of some of the "high context" aspects of the small-group interactions into our current lecture-based course with the addition of on-line PBL cases.

  9. 24 CFR 5.613 - Public housing program and Section 8 tenant-based assistance program: PHA cooperation with...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 8 tenant-based assistance program: PHA cooperation with welfare agency. 5.613 Section 5.613 Housing... cooperation with welfare agency. (a) This section applies to the public housing program and the Section 8... with welfare agencies under which such agencies agree: (1) To target public assistance, benefits and...

  10. 24 CFR 5.613 - Public housing program and Section 8 tenant-based assistance program: PHA cooperation with...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 8 tenant-based assistance program: PHA cooperation with welfare agency. 5.613 Section 5.613 Housing... cooperation with welfare agency. (a) This section applies to the public housing program and the Section 8... with welfare agencies under which such agencies agree: (1) To target public assistance, benefits and...

  11. 24 CFR 5.613 - Public housing program and Section 8 tenant-based assistance program: PHA cooperation with...

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 8 tenant-based assistance program: PHA cooperation with welfare agency. 5.613 Section 5.613 Housing... cooperation with welfare agency. (a) This section applies to the public housing program and the Section 8... with welfare agencies under which such agencies agree: (1) To target public assistance, benefits and...

  12. 24 CFR 5.613 - Public housing program and Section 8 tenant-based assistance program: PHA cooperation with...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 8 tenant-based assistance program: PHA cooperation with welfare agency. 5.613 Section 5.613 Housing... cooperation with welfare agency. (a) This section applies to the public housing program and the Section 8... with welfare agencies under which such agencies agree: (1) To target public assistance, benefits and...

  13. 24 CFR 5.613 - Public housing program and Section 8 tenant-based assistance program: PHA cooperation with...

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 8 tenant-based assistance program: PHA cooperation with welfare agency. 5.613 Section 5.613 Housing... cooperation with welfare agency. (a) This section applies to the public housing program and the Section 8... with welfare agencies under which such agencies agree: (1) To target public assistance, benefits and...

  14. Exploring Pre-Service Teachers' Historical Thinking through the Cooperative Biography: A Design-Based Research Study

    ERIC Educational Resources Information Center

    Fuentes, David A.

    2012-01-01

    Through Design-Based Research (Cobb, et al., 2003), this study explores the intended outcomes and processes of the Cooperative Biography project. This research provides an "iterative analysis" (Cobb, et al., 2003) of how pre-service teachers experienced history while engaged in a Cooperative Biography, in a teacher-education setting.…

  15. Exploring Pre-Service Teachers' Historical Thinking through the Cooperative Biography: A Design-Based Research Study

    ERIC Educational Resources Information Center

    Fuentes, David A.

    2012-01-01

    Through Design-Based Research (Cobb, et al., 2003), this study explores the intended outcomes and processes of the Cooperative Biography project. This research provides an "iterative analysis" (Cobb, et al., 2003) of how pre-service teachers experienced history while engaged in a Cooperative Biography, in a teacher-education setting.…

  16. Incremental inverse kinematics based vision servo for autonomous robotic capture of non-cooperative space debris

    NASA Astrophysics Data System (ADS)

    Dong, Gangqi; Zhu, Z. H.

    2016-04-01

    This paper proposed a new incremental inverse kinematics based vision servo approach for robotic manipulators to capture a non-cooperative target autonomously. The target's pose and motion are estimated by a vision system using integrated photogrammetry and EKF algorithm. Based on the estimated pose and motion of the target, the instantaneous desired position of the end-effector is predicted by inverse kinematics and the robotic manipulator is moved incrementally from its current configuration subject to the joint speed limits. This approach effectively eliminates the multiple solutions in the inverse kinematics and increases the robustness of the control algorithm. The proposed approach is validated by a hardware-in-the-loop simulation, where the pose and motion of the non-cooperative target is estimated by a real vision system. The simulation results demonstrate the effectiveness and robustness of the proposed estimation approach for the target and the incremental control strategy for the robotic manipulator.

  17. NetCoDer: A Retransmission Mechanism for WSNs Based on Cooperative Relays and Network Coding.

    PubMed

    Valle, Odilson T; Montez, Carlos; Medeiros de Araujo, Gustavo; Vasques, Francisco; Moraes, Ricardo

    2016-05-31

    Some of the most difficult problems to deal with when using Wireless Sensor Networks (WSNs) are related to the unreliable nature of communication channels. In this context, the use of cooperative diversity techniques and the application of network coding concepts may be promising solutions to improve the communication reliability. In this paper, we propose the NetCoDer scheme to address this problem. Its design is based on merging cooperative diversity techniques and network coding concepts. We evaluate the effectiveness of the NetCoDer scheme through both an experimental setup with real WSN nodes and a simulation assessment, comparing NetCoDer performance against state-of-the-art TDMA-based (Time Division Multiple Access) retransmission techniques: BlockACK, Master/Slave and Redundant TDMA. The obtained results highlight that the proposed NetCoDer scheme clearly improves the network performance when compared with other retransmission techniques.

  18. NASA/RAE cooperation on a knowlede based flight status monitor

    NASA Technical Reports Server (NTRS)

    Butler, G. F.; Duke, E. L.

    1989-01-01

    As part of a US/UK cooperative aeronautical research pragram, a joint activity between the Dryden Flight Research Facility of the NASA Ames Research Center (Ames-Dryden) and the Royal Aerospace Establishment (RAE) on Knowledge Based Systems was established. Under the agreement, a Flight Status Monitor Knowledge base developed at Ames-Dryden was implemented using the real-time IKBS toolkit, MUSE, which was developed in the UK under RAE sponsorship. The Flight Status Monitor is designed to provide on-line aid to the flight test engineer in the interpretation of system health and status by storing expert knowledge of system behavior in an easily accessible form. The background to the cooperation is described and the details of the Flight Status Monitor, the MUSE implementation are presented.

  19. NetCoDer: A Retransmission Mechanism for WSNs Based on Cooperative Relays and Network Coding

    PubMed Central

    Valle, Odilson T.; Montez, Carlos; Medeiros de Araujo, Gustavo; Vasques, Francisco; Moraes, Ricardo

    2016-01-01

    Some of the most difficult problems to deal with when using Wireless Sensor Networks (WSNs) are related to the unreliable nature of communication channels. In this context, the use of cooperative diversity techniques and the application of network coding concepts may be promising solutions to improve the communication reliability. In this paper, we propose the NetCoDer scheme to address this problem. Its design is based on merging cooperative diversity techniques and network coding concepts. We evaluate the effectiveness of the NetCoDer scheme through both an experimental setup with real WSN nodes and a simulation assessment, comparing NetCoDer performance against state-of-the-art TDMA-based (Time Division Multiple Access) retransmission techniques: BlockACK, Master/Slave and Redundant TDMA. The obtained results highlight that the proposed NetCoDer scheme clearly improves the network performance when compared with other retransmission techniques. PMID:27258280

  20. A novel hazard assessment method for biomass gasification stations based on extended set pair analysis.

    PubMed

    Yan, Fang; Xu, Kaili; Li, Deshun; Cui, Zhikai

    2017-01-01

    Biomass gasification stations are facing many hazard factors, therefore, it is necessary to make hazard assessment for them. In this study, a novel hazard assessment method called extended set pair analysis (ESPA) is proposed based on set pair analysis (SPA). However, the calculation of the connection degree (CD) requires the classification of hazard grades and their corresponding thresholds using SPA for the hazard assessment. In regard to the hazard assessment using ESPA, a novel calculation algorithm of the CD is worked out when hazard grades and their corresponding thresholds are unknown. Then the CD can be converted into Euclidean distance (ED) by a simple and concise calculation, and the hazard of each sample will be ranked based on the value of ED. In this paper, six biomass gasification stations are introduced to make hazard assessment using ESPA and general set pair analysis (GSPA), respectively. By the comparison of hazard assessment results obtained from ESPA and GSPA, the availability and validity of ESPA can be proved in the hazard assessment for biomass gasification stations. Meanwhile, the reasonability of ESPA is also justified by the sensitivity analysis of hazard assessment results obtained by ESPA and GSPA.

  1. A novel hazard assessment method for biomass gasification stations based on extended set pair analysis

    PubMed Central

    Yan, Fang; Xu, Kaili; Li, Deshun; Cui, Zhikai

    2017-01-01

    Biomass gasification stations are facing many hazard factors, therefore, it is necessary to make hazard assessment for them. In this study, a novel hazard assessment method called extended set pair analysis (ESPA) is proposed based on set pair analysis (SPA). However, the calculation of the connection degree (CD) requires the classification of hazard grades and their corresponding thresholds using SPA for the hazard assessment. In regard to the hazard assessment using ESPA, a novel calculation algorithm of the CD is worked out when hazard grades and their corresponding thresholds are unknown. Then the CD can be converted into Euclidean distance (ED) by a simple and concise calculation, and the hazard of each sample will be ranked based on the value of ED. In this paper, six biomass gasification stations are introduced to make hazard assessment using ESPA and general set pair analysis (GSPA), respectively. By the comparison of hazard assessment results obtained from ESPA and GSPA, the availability and validity of ESPA can be proved in the hazard assessment for biomass gasification stations. Meanwhile, the reasonability of ESPA is also justified by the sensitivity analysis of hazard assessment results obtained by ESPA and GSPA. PMID:28938011

  2. Object tracking with robotic total stations: Current technologies and improvements based on image data

    NASA Astrophysics Data System (ADS)

    Ehrhart, Matthias; Lienhart, Werner

    2017-09-01

    The importance of automated prism tracking is increasingly triggered by the rising automation of total station measurements in machine control, monitoring and one-person operation. In this article we summarize and explain the different techniques that are used to coarsely search a prism, to precisely aim at a prism, and to identify whether the correct prism is tracked. Along with the state-of-the-art review, we discuss and experimentally evaluate possible improvements based on the image data of an additional wide-angle camera which is available for many total stations today. In cases in which the total station's fine aiming module loses the prism, the tracked object may still be visible to the wide-angle camera because of its larger field of view. The theodolite angles towards the target can then be derived from its image coordinates which facilitates a fast reacquisition of the prism. In experimental measurements we demonstrate that our image-based approach for the coarse target search is 4 to 10-times faster than conventional approaches.

  3. Optic flow based station-keeping and wind rejection for small flying vehicles

    NASA Astrophysics Data System (ADS)

    Patrick, Bryan

    Optic flow and Wide Field Integration (WFI) have shown potential for application to autonomous navigation of Unmanned Air Vehicles (UAVs). In this study the application of these same methods to other tasks, namely station-keeping and wind rejection, is examined. Theory surrounding optic flow, WFI and wind gust modeling is examined to provide a theoretical background. A controller based on a Hinfinity bounded formulation of the well known Linear Quadratic Regulator in designed to both mitigate wind disturbances and station-keep. The performance of this controller is assessed via simulation to determine both performance and trade-offs in implementation such as the method for optic flow calculation. Furthermore, flight tests are performed to examine the real world effectiveness of the controller. Finally, conclusions about potential improvement to implementation are drawn

  4. Operational and biological effects zones from base stations of cellular telephony

    SciTech Connect

    Geronikolou, St. A.; Zimeras, S.; Tsitomeneas, S. Th.

    2016-03-25

    The possible environmental impacts of cellular base stations are operational and biological. The operational effects comprise Εlectro-Μagnetic Interference (EMI), lightning alterations and aesthetic degradation. Both thermal and non-thermal biological effects depend on the absorption of UHF radiofrequencies used. We measured, calculated and estimated the impact zones. The results are: (a) The lightning lethal zone equal to the antenna height, (b) the EMI impact in a zone up to 40m and (c) the ICNIRP’s limits exceed to a zone of 8∼20m into the antenna’s radiation pattern (for 2G GSM and 3G UMTS station). Finally we conclude the adverse effects must not expected in a zone of more than 150m from the radiated antenna, whereas, there is possibility of stochastic effects in intermediate distances (20/40-150m).

  5. An IBM PC-based math model for space station solar array simulation

    NASA Technical Reports Server (NTRS)

    Emanuel, E. M.

    1986-01-01

    This report discusses and documents the design, development, and verification of a microcomputer-based solar cell math model for simulating the Space Station's solar array Initial Operational Capability (IOC) reference configuration. The array model is developed utilizing a linear solar cell dc math model requiring only five input parameters: short circuit current, open circuit voltage, maximum power voltage, maximum power current, and orbit inclination. The accuracy of this model is investigated using actual solar array on orbit electrical data derived from the Solar Array Flight Experiment/Dynamic Augmentation Experiment (SAFE/DAE), conducted during the STS-41D mission. This simulator provides real-time simulated performance data during the steady state portion of the Space Station orbit (i.e., array fully exposed to sunlight). Eclipse to sunlight transients and shadowing effects are not included in the analysis, but are discussed briefly. Integrating the Solar Array Simulator (SAS) into the Power Management and Distribution (PMAD) subsystem is also discussed.

  6. An IBM PC-based math model for space station solar array simulation

    NASA Technical Reports Server (NTRS)

    Emanuel, E. M.

    1986-01-01

    This report discusses and documents the design, development, and verification of a microcomputer-based solar cell math model for simulating the Space Station's solar array Initial Operational Capability (IOC) reference configuration. The array model is developed utilizing a linear solar cell dc math model requiring only five input parameters: short circuit current, open circuit voltage, maximum power voltage, maximum power current, and orbit inclination. The accuracy of this model is investigated using actual solar array on orbit electrical data derived from the Solar Array Flight Experiment/Dynamic Augmentation Experiment (SAFE/DAE), conducted during the STS-41D mission. This simulator provides real-time simulated performance data during the steady state portion of the Space Station orbit (i.e., array fully exposed to sunlight). Eclipse to sunlight transients and shadowing effects are not included in the analysis, but are discussed briefly. Integrating the Solar Array Simulator (SAS) into the Power Management and Distribution (PMAD) subsystem is also discussed.

  7. Determinants of enrollment of informal sector workers in cooperative based health scheme in Bangladesh.

    PubMed

    Sarker, Abdur Razzaque; Sultana, Marufa; Mahumud, Rashidul Alam; Ahmed, Sayem; Islam, Ziaul; Morton, Alec; Khan, Jahangir A M

    2017-01-01

    Providing access to affordable health care for the informal sector remains a considerable challenge for low income countries striving to make progress towards universal health coverage. The objective of the study is to identify the factors shaping the decision to enroll in a cooperative based health scheme for informal workers in Bangladesh and also help to identify the features of informal workers without health schemes and their likelihood of being insured. Data were derived from a cross-sectional in-house survey within the catchment area of a cooperative based health scheme in Bangladesh during April-June 2014, covering a total of 784 households (458 members and 326 non-members). Multivariate logistic regression model was used to identify factors associated with cooperative based health scheme and explanatory variables. This study found that a number of factors were significant determinants of health scheme participation including sex of household head, household composition, occupational category as well as involvement social financial safety net programs. Findings from this study can be suggestive for policy-makers interested in scaling up health insurance for informal workers in Bangladesh. Shared funding from this large informal sector can generate new resources for healthcare, which is in line with the healthcare financing strategy of Bangladesh as well as the recommendation of the World Health Organization for developing social health insurance as part of the path to Universal Health Coverage.

  8. Determinants of enrollment of informal sector workers in cooperative based health scheme in Bangladesh

    PubMed Central

    Sarker, Abdur Razzaque; Sultana, Marufa; Mahumud, Rashidul Alam; Ahmed, Sayem; Islam, Ziaul; Morton, Alec; Khan, Jahangir A. M.

    2017-01-01

    Background Providing access to affordable health care for the informal sector remains a considerable challenge for low income countries striving to make progress towards universal health coverage. The objective of the study is to identify the factors shaping the decision to enroll in a cooperative based health scheme for informal workers in Bangladesh and also help to identify the features of informal workers without health schemes and their likelihood of being insured. Methods Data were derived from a cross-sectional in-house survey within the catchment area of a cooperative based health scheme in Bangladesh during April–June 2014, covering a total of 784 households (458 members and 326 non-members). Multivariate logistic regression model was used to identify factors associated with cooperative based health scheme and explanatory variables. Findings This study found that a number of factors were significant determinants of health scheme participation including sex of household head, household composition, occupational category as well as involvement social financial safety net programs. Conclusion Findings from this study can be suggestive for policy-makers interested in scaling up health insurance for informal workers in Bangladesh. Shared funding from this large informal sector can generate new resources for healthcare, which is in line with the healthcare financing strategy of Bangladesh as well as the recommendation of the World Health Organization for developing social health insurance as part of the path to Universal Health Coverage. PMID:28750052

  9. Study of the National Science Foundation's South Pole Station as an analogous data base for the logistical support of a Moon laboratory

    NASA Technical Reports Server (NTRS)

    Hickam, H. H., Jr.

    1993-01-01

    The day will come when the United States will want to return to the Earth's Moon. When that occurs, NASA may look to the Apollo program for technical and inspirational guidance. The Apollo program, however, was designed to be an end to itself--the landing of a man on the Moon and his return safely within the decade of the 1960's. When that was accomplished, the program folded because it was not self-sustaining. The next time we return to the Moon, we should base our planning on a program that is designed to be a sustained effort for an indefinite period. It is the thrust of this report that the South Pole Station of the National Science Foundation can be used to develop analogs for the construction, funding, and logistical support of a lunar base. Other analogs include transportation and national efforts versus international cooperation. A recommended lunar base using the South Pole Station as inspiration is provided, as well as details concerning economical construction of the base over a 22-year period.

  10. Factors influencing cooperation among healthcare providers in a community-based stroke care system in Japan.

    PubMed

    Koga, Masatoshi; Uehara, Toshiyuki; Yasui, Nobuyuki; Hasegawa, Yasuhiro; Nagatsuka, Kazuyuki; Okada, Yasushi; Minematsu, Kazuo

    2011-01-01

    Community-based stroke care in Japan is currently provided in acute hospitals, convalescent rehabilitation units, general practices, sanatorium-type wards, nursing care facilities, and in-home/commuting care services. We conducted a nationwide survey to identify factors influencing cooperation among the various providers of community-based stroke care. We sent questionnaires to 11,178 facilities and assessed the independent variables of excellent and fair cooperation among the care providers. Of the providers that responded, 66% were engaged in medical practice or long-term care for stroke patients. The following independent variables were inversely associated with excellent or fair cooperation in the community: area with the higher population density among 3 groups divided by tertile threshold (odds ratio [OR], 0.53; 95% confidence interval [CI], 0.41-0.69), facilities covered by long-term care insurance (OR, 0.27; 95% CI, 0.22-0.34), and insufficient communication with local government (OR, 0.19; 95% CI, 0.14-0.24). Positive independent variables of excellent or fair cooperation were the sharing of patient information in the community (OR, 2.53; 95% CI, 1.78-3.66), use of a scale for assessing activities of daily living (OR, 1.93; 95% CI, 1.42-2.63), appropriate utilization of care support managers (OR, 1.91; 95% CI, 1.43-2.55), and adequate comprehension of the long-term care insurance system (OR, 1.54; 95% CI, 1.24-1.92). Our findings suggest that improved communication between healthcare providers and local government, along with appropriate attention to the problems facing providers covered by long-term care insurance, may improve community-based stroke care in Japan. Copyright © 2011 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  11. The google map based permanent infrasound station positioning decision support program for the world scale.

    NASA Astrophysics Data System (ADS)

    Lee, S.

    2016-12-01

    The permanent infrasound station was decided by the importance of the distance and noise conditions of the installed location. The first priority of the station location are signal to noise ratios for the clear identification from the background. After the installation was finished, it could not be possible to transfer to another location for the time and costs and continuous recording availability. The minimum required space for the independent infrasound station could be 10m square, the survey for the site construction should be absolute. But the survey need time and field trip budget, so the decision support program for the preliminary results could be very helpful. The google map was used to check the land use availability and construction accessibility. The decision support program support the initial ideal array design and theoretical array function from the array shape and inter-distance which could be adjustable based on direct input on the google map for the sensor location. The real examination case was reviewed also.

  12. Cooperative Game-Based Energy Efficiency Management over Ultra-Dense Wireless Cellular Networks.

    PubMed

    Li, Ming; Chen, Pengpeng; Gao, Shouwan

    2016-09-13

    Ultra-dense wireless cellular networks have been envisioned as a promising technique for handling the explosive increase of wireless traffic volume. With the extensive deployment of small cells in wireless cellular networks, the network spectral efficiency (SE) is improved with the use of limited frequency. However, the mutual inter-tier and intra-tier interference between or among small cells and macro cells becomes serious. On the other hand, more chances for potential cooperation among different cells are introduced. Energy efficiency (EE) has become one of the most important problems for future wireless networks. This paper proposes a cooperative bargaining game-based method for comprehensive EE management in an ultra-dense wireless cellular network, which highlights the complicated interference influence on energy-saving challenges and the power-coordination process among small cells and macro cells. Especially, a unified EE utility with the consideration of the interference mitigation is proposed to jointly address the SE, the deployment efficiency (DE), and the EE. In particular, closed-form power-coordination solutions for the optimal EE are derived to show the convergence property of the algorithm. Moreover, a simplified algorithm is presented to reduce the complexity of the signaling overhead, which is significant for ultra-dense small cells. Finally, numerical simulations are provided to illustrate the efficiency of the proposed cooperative bargaining game-based and simplified schemes.

  13. Cooperative Game-Based Energy Efficiency Management over Ultra-Dense Wireless Cellular Networks

    PubMed Central

    Li, Ming; Chen, Pengpeng; Gao, Shouwan

    2016-01-01

    Ultra-dense wireless cellular networks have been envisioned as a promising technique for handling the explosive increase of wireless traffic volume. With the extensive deployment of small cells in wireless cellular networks, the network spectral efficiency (SE) is improved with the use of limited frequency. However, the mutual inter-tier and intra-tier interference between or among small cells and macro cells becomes serious. On the other hand, more chances for potential cooperation among different cells are introduced. Energy efficiency (EE) has become one of the most important problems for future wireless networks. This paper proposes a cooperative bargaining game-based method for comprehensive EE management in an ultra-dense wireless cellular network, which highlights the complicated interference influence on energy-saving challenges and the power-coordination process among small cells and macro cells. Especially, a unified EE utility with the consideration of the interference mitigation is proposed to jointly address the SE, the deployment efficiency (DE), and the EE. In particular, closed-form power-coordination solutions for the optimal EE are derived to show the convergence property of the algorithm. Moreover, a simplified algorithm is presented to reduce the complexity of the signaling overhead, which is significant for ultra-dense small cells. Finally, numerical simulations are provided to illustrate the efficiency of the proposed cooperative bargaining game-based and simplified schemes. PMID:27649170

  14. Cost-Sharing of Ecological Construction Based on Trapezoidal Intuitionistic Fuzzy Cooperative Games.

    PubMed

    Liu, Jiacai; Zhao, Wenjian

    2016-11-08

    There exist some fuzziness and uncertainty in the process of ecological construction. The aim of this paper is to develop a direct and an effective simplified method for obtaining the cost-sharing scheme when some interested parties form a cooperative coalition to improve the ecological environment of Min River together. Firstly, we propose the solution concept of the least square prenucleolus of cooperative games with coalition values expressed by trapezoidal intuitionistic fuzzy numbers. Then, based on the square of the distance in the numerical value between two trapezoidal intuitionistic fuzzy numbers, we establish a corresponding quadratic programming model to obtain the least square prenucleolus, which can effectively avoid the information distortion and uncertainty enlargement brought about by the subtraction of trapezoidal intuitionistic fuzzy numbers. Finally, we give a numerical example about the cost-sharing of ecological construction in Fujian Province in China to show the validity, applicability, and advantages of the proposed model and method.

  15. Cost-Sharing of Ecological Construction Based on Trapezoidal Intuitionistic Fuzzy Cooperative Games

    PubMed Central

    Liu, Jiacai; Zhao, Wenjian

    2016-01-01

    There exist some fuzziness and uncertainty in the process of ecological construction. The aim of this paper is to develop a direct and an effective simplified method for obtaining the cost-sharing scheme when some interested parties form a cooperative coalition to improve the ecological environment of Min River together. Firstly, we propose the solution concept of the least square prenucleolus of cooperative games with coalition values expressed by trapezoidal intuitionistic fuzzy numbers. Then, based on the square of the distance in the numerical value between two trapezoidal intuitionistic fuzzy numbers, we establish a corresponding quadratic programming model to obtain the least square prenucleolus, which can effectively avoid the information distortion and uncertainty enlargement brought about by the subtraction of trapezoidal intuitionistic fuzzy numbers. Finally, we give a numerical example about the cost-sharing of ecological construction in Fujian Province in China to show the validity, applicability, and advantages of the proposed model and method. PMID:27834830

  16. Evaluation of FCS self and peer-assessment approach based on Cooperative and Engineering Design learning.

    PubMed

    Cvetkovic, Dean

    2013-01-01

    The Cooperative Learning in Engineering Design curriculum can be enhanced with structured and timely self and peer assessment teaching methodologies which can easily be applied to any Biomedical Engineering curriculum. A study was designed and implemented to evaluate the effectiveness of this structured and timely self and peer assessment on student team-based projects. In comparing the 'peer-blind' and 'face-to-face' Fair Contribution Scoring (FCS) methods, both had advantages and disadvantages. The 'peer-blind' self and peer assessment method would cause high discrepancy between self and team ratings. But the 'face-to-face' method on the other hand did not have the discrepancy issue and had actually proved to be a more accurate and effective, indicating team cohesiveness and good cooperative learning.

  17. The NASA Space Station program plans

    NASA Technical Reports Server (NTRS)

    Freitag, R. F.

    1984-01-01

    The design of a permanently manned space station is discussed. The role of the space shuttle, planning guidelines, international cooperation, and commercial possibilities are among the topics discussed.

  18. Space station, 1959 to . .

    NASA Astrophysics Data System (ADS)

    Butler, G. V.

    1981-04-01

    Early space station designs are considered, taking into account Herman Oberth's first space station, the London Daily Mail Study, the first major space station design developed during the moon mission, and the Manned Orbiting Laboratory Program of DOD. Attention is given to Skylab, new space station studies, the Shuttle and Spacelab, communication satellites, solar power satellites, a 30 meter diameter radiometer for geological measurements and agricultural assessments, the mining of the moons, and questions of international cooperation. It is thought to be very probable that there will be very large space stations at some time in the future. However, for the more immediate future a step-by-step development that will start with Spacelab stations of 3-4 men is envisaged.

  19. A large-scale measurement of electromagnetic fields near GSM base stations in Guangxi, China for risk communication.

    PubMed

    Wu, Tongning; Shao, Qing; Yang, Lei; Qi, Dianyuan; Lin, Jun; Lin, Xiaojun; Yu, Zongying

    2013-06-01

    Radiofrequency (RF) electromagnetic field (EMF) exposure from wireless telecommunication base station antennae can lead to debates, conflicts or litigations among the adjacent residents if inappropriately managed. This paper presents a measurement campaign for the GSM band EMF exposure in the vicinity of 827 base station sites (totally 6207 measurement points) in Guangxi, China. Measurement specifications are designed for risk communication with the residents who previously complained of over-exposure. The EMF power densities with the global positioning system coordinate at each measured point were recorded. Compliance with the International Commission on Non-Ionizing Radiation Protection guidelines and Chinese environmental EMF safety standards was studied. The results show that the GSM band EMF level near the base stations is very low. The measurement results and the EMF risk communication procedures positively influence public perception of the RF EMF exposure from the base stations and promote the exchange of EMF exposure-related knowledge.

  20. The effect of Base Transceiver Station waves on some immunological and hematological factors in exposed persons.

    PubMed

    Taheri, Mohammad; Roshanaei, Ghodratollah; Ghaffari, Jamileh; Rahimnejad, Samira; Khosroshahi, Behzad Nazel; Aliabadi, Mohsen; Eftekharian, Mohammad Mahdi

    2017-01-01

    Since the number of mobile subscribers has significantly increased in recent years, the installation and deployment of Base Transceiver Station (BTS) antennas sending and receiving signals has become common and inevitable in different regions. In this study, we have tried to evaluate the effect of the waves on some immunological and hematological parameters in exposed individuals. In this study, the exposed and non-exposed individuals were used as the test and control groups, respectively. The test group was healthy people who resided in the vicinity of the Base Transceiver Station (BTS) antenna and received the maximum of radiation. The control group was selected from the healthy individuals that were matched with the exposed group by age. They resided in a distance of Base Transceiver Station (BTS) antenna and received the minimum of radiation. After stating complete explanations and obtaining the consent, the venous blood samples were taken from them. Then, CBC and the level of cytokines including IL-4, IL-10 and interferon γ were performed on the samples and the results were analyzed by SPSS software. In the test group, the whole number of white blood cells, the level of hematocrit, percent of monocytes, eosinophils and basophils were significantly lower than the control group. The number of red blood cells, their average volume and the mean concentration of hemoglobin were notably higher than the controls. There was not observed a significant difference between the two groups in hemoglobin, its mean concentration, platelet count, percent of lymphocytes and neutrophils as well as serum levels of cytokines IL-4, IL-10 and interferon γ . It seems that radiation of mobile phone antennas influenced the blood and immune systems, but further study should be done to exactly determine the targets.

  1. Optimal Consensus Based Decentralized Cooperative Spectrum Sensing in Cognitive Radio Networks

    NASA Astrophysics Data System (ADS)

    Shen, Liang; Xu, Yuhua; Gao, Zhan; Wu, Qihui

    2013-03-01

    We study the problem of decentralized cooperative spectrum sensing in cognitive radio ad hoc networks without a fusion center, using a consensus based solution. First, the received logarithmic likelihood ratio (LLR) is employed as the local detection outcome; then, it is exchanged between neighboring CR users and is updated based on the LLR received from the neighbors. It is proved that with the proposed decentralized algorithm, the optimal sensing performance is achieved via just local information exchange between neighbors. In addition, it is shown that the proposed algorithm outperforms previous work in which the received energy was employed as the local detection outcome.

  2. A transition metal Lewis acid/base triad system for cooperative substrate binding.

    PubMed

    Tutusaus, Oscar; Ni, Chengbao; Szymczak, Nathaniel K

    2013-03-06

    A frustrated Lewis pair accessory functionality is positioned in the secondary coordination sphere of a terpyridine ligand (Tpy(BN) = 6-morpholino-2,2':6',2″-terpyridine-6″-boronic acid pinacol ester) to promote directed Lewis acid/base interactions. Following metalation with VCl3, the utility of the metal Lewis acid/base triad (LABT) is highlighted with N2H4 as a cooperatively coordinated substrate, affording the first η(2)-[N2H3](-) vanadium complex.

  3. An erbium-based bifuctional heterogeneous catalyst: a cooperative route towards C-C bond formation.

    PubMed

    Oliverio, Manuela; Costanzo, Paola; Macario, Anastasia; De Luca, Giuseppina; Nardi, Monica; Procopio, Antonio

    2014-07-15

    Heterogeneous bifuctional catalysts are multifunctional synthetic catalysts enabling efficient organic transformations by exploiting two opposite functionalities without mutual destruction. In this paper we report the first Er(III)-based metallorganic heterogeneous catalyst, synthesized by post-calcination MW-assisted grafting and modification of the natural aminoacid L-cysteine. The natural acid-base distance between sites was maintained to assure the cooperation. The applicability of this new bifunctional heterogeneous catalyst to C-C bond formation and the supposed mechanisms of action are discussed as well.

  4. Relative Packing Groups in Template-Based Structure Prediction: Cooperative Effects of True Positive Constraints

    PubMed Central

    Day, Ryan; Qu, Xiaotao; Swanson, Rosemarie; Bohannan, Zach; Bliss, Robert

    2011-01-01

    Abstract Most current template-based structure prediction methods concentrate on finding the correct backbone conformation and then packing sidechains within that backbone. Our packing-based method derives distance constraints from conserved relative packing groups (RPGs). In our refinement approach, the RPGs provide a level of resolution that restrains global topology while allowing conformational sampling. In this study, we test our template-based structure prediction method using 51 prediction units from CASP7 experiments. RPG-based constraints are able to substantially improve approximately two-thirds of starting templates. Upon deeper investigation, we find that true positive spatial constraints, especially those non-local in sequence, derived from the RPGs were important to building nearer native models. Surprisingly, the fraction of incorrect or false positive constraints does not strongly influence the quality of the final candidate. This result indicates that our RPG-based true positive constraints sample the self-consistent, cooperative interactions of the native structure. The lack of such reinforcing cooperativity explains the weaker effect of false positive constraints. Generally, these findings are encouraging indications that RPGs will improve template-based structure prediction. PMID:21210729

  5. Relative packing groups in template-based structure prediction: cooperative effects of true positive constraints.

    PubMed

    Day, Ryan; Qu, Xiaotao; Swanson, Rosemarie; Bohannan, Zach; Bliss, Robert; Tsai, Jerry

    2011-01-01

    Most current template-based structure prediction methods concentrate on finding the correct backbone conformation and then packing sidechains within that backbone. Our packing-based method derives distance constraints from conserved relative packing groups (RPGs). In our refinement approach, the RPGs provide a level of resolution that restrains global topology while allowing conformational sampling. In this study, we test our template-based structure prediction method using 51 prediction units from CASP7 experiments. RPG-based constraints are able to substantially improve approximately two-thirds of starting templates. Upon deeper investigation, we find that true positive spatial constraints, especially those non-local in sequence, derived from the RPGs were important to building nearer native models. Surprisingly, the fraction of incorrect or false positive constraints does not strongly influence the quality of the final candidate. This result indicates that our RPG-based true positive constraints sample the self-consistent, cooperative interactions of the native structure. The lack of such reinforcing cooperativity explains the weaker effect of false positive constraints. Generally, these findings are encouraging indications that RPGs will improve template-based structure prediction.

  6. The Environment Friendly Power Source for Power Supply of Mobile Communication Base Stations

    NASA Astrophysics Data System (ADS)

    Rudenko, N. V.; Ershov, V. V.; Evstafiev, V. V.

    2017-05-01

    The article describes the technical proposals to improve environmental and resource characteristics of the autonomous power supply systems of mobile communication base stations based on renewable energy sources, while ensuring the required reliability and security of power supply. These include: the replacement of diesel-generator with clean energy source - an electrochemical generator based on hydrogen fuel cells; the use of wind turbines with a vertical axis; use of specialized batteries. Based on the analysis of the know technical solutions, the structural circuit diagram of the hybrid solar-wind-hydrogen power plant and the basic principles of the algorithm of its work were proposed. The implementation of these proposals will improve the environmental and resource characteristics.

  7. The ARM Best Estimate Station-based Surface (ARMBESTNS) Data set

    DOE Data Explorer

    Qi,Tang; Xie,Shaocheng

    2015-08-06

    The ARM Best Estimate Station-based Surface (ARMBESTNS) data set merges together key surface measurements from the Southern Great Plains (SGP) sites. It is a twin data product of the ARM Best Estimate 2-dimensional Gridded Surface (ARMBE2DGRID) data set. Unlike the 2DGRID data set, the STNS data are reported at the original site locations and show the original information, except for the interpolation over time. Therefore, users have the flexibility to process the data with the approach more suitable for their applications.

  8. How does long term exposure to base stations and mobile phones affect human hormone profiles?

    PubMed

    Eskander, Emad F; Estefan, Selim F; Abd-Rabou, Ahmed A

    2012-01-01

    This study is concerned with assessing the role of exposure to radio frequency radiation (RFR) emitted either from mobiles or base stations and its relations with human's hormone profiles. All volunteers' samples were collected for hormonal analysis. This study showed significant decrease in volunteers' ACTH, cortisol, thyroid hormones, prolactin for young females, and testosterone levels. The present study revealed that high RFR effects on pituitary-adrenal axis. Copyright © 2011 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  9. Cooperative Transmission for Relay Networks Based on Second-Order Statistics of Channel State Information

    NASA Astrophysics Data System (ADS)

    Li, Jiangyuan; Petropulu, Athina P.; Poor, H. Vincent

    2011-03-01

    Cooperative beamforming in relay networks is considered, in which a source transmits to its destination with the help of a set of cooperating nodes. The source first transmits locally. The cooperating nodes that receive the source signal retransmit a weighted version of it in an amplify-and-forward (AF) fashion. Assuming knowledge of the second-order statistics of the channel state information, beamforming weights are determined so that the signal-to-noise ratio (SNR) at the destination is maximized subject to two different power constraints, i.e., a total (source and relay) power constraint, and individual relay power constraints. For the former constraint, the original problem is transformed into a problem of one variable, which can be solved via Newton's method. For the latter constraint, the original problem is transformed into a homogeneous quadratically constrained quadratic programming (QCQP) problem. In this case, it is shown that when the number of relays does not exceed three the global solution can always be constructed via semidefinite programming (SDP) relaxation and the matrix rank-one decomposition technique. For the cases in which the SDP relaxation does not generate a rank one solution, two methods are proposed to solve the problem: the first one is based on the coordinate descent method, and the second one transforms the QCQP problem into an infinity norm maximization problem in which a smooth finite norm approximation can lead to the solution using the augmented Lagrangian method.

  10. Evolutionary, neurobiological, gene-based solution of the ideological "puzzle" of human altruism and cooperation.

    PubMed

    Baschetti, Riccardo

    2007-01-01

    Despite hundreds of published articles about humankind's eusocial behaviours, most scholars still regard the origin of human altruism and cooperation as an enduring puzzle, because it seems incompatible with two central tenets of evolution, namely, the competition between individuals and the consequent selective advantages of selfish traits. This "puzzle", however, rather than being due to insurmountable scientific difficulties, is to be attributed to two powerful ideologies, which are politically opposite, but nevertheless concurred to prevent scholars from solving it. One ideology rejects the concept of genetic determinism, whereas the other dislikes the concept of group selection. As a consequence, these widespread ideologies, which are common in the scientific community, too, kept scholars from realising that the puzzle of human altruism and cooperation can only be solved by proposing a theoretical model that is based precisely on both genetic determinism and group selection. This model, which was never advanced in published papers, is presented here. This article also proposes to regard ancestral environments as determinants of human eusociality. By contrast, virtually all previous articles about it leave primitive habitats unmentioned. To support the hypothesis that human unselfish behaviours represent genetically conserved traits that evolved ancestrally, not products of cultural transmission, this paper also discusses six groups of arguments in the section "Genes versus culture". Finally, this article advances a purely genetic evolutionary explanation for the uniqueness of human eusociality, thereby challenging prevailing cultural explanations for the incomparably developed levels of cooperation in humankind, which are observed in no other social species.

  11. A Consensus-Based Grouping Algorithm for Multi-agent Cooperative Task Allocation with Complex Requirements.

    PubMed

    Hunt, Simon; Meng, Qinggang; Hinde, Chris; Huang, Tingwen

    2014-01-01

    This paper looks at consensus algorithms for agent cooperation with unmanned aerial vehicles. The foundation is the consensus-based bundle algorithm, which is extended to allow multi-agent tasks requiring agents to cooperate in completing individual tasks. Inspiration is taken from the cognitive behaviours of eusocial animals for cooperation and improved assignments. Using the behaviours observed in bees and ants inspires decentralised algorithms for groups of agents to adapt to changing task demand. Further extensions are provided to improve task complexity handling by the agents with added equipment requirements and task dependencies. We address the problems of handling these challenges and improve the efficiency of the algorithm for these requirements, whilst decreasing the communication cost with a new data structure. The proposed algorithm converges to a conflict-free, feasible solution of which previous algorithms are unable to account for. Furthermore, the algorithm takes into account heterogeneous agents, deadlocking and a method to store assignments for a dynamical environment. Simulation results demonstrate reduced data usage and communication time to come to a consensus on multi-agent tasks.

  12. Particle filter-based relative rolling estimation algorithm for non-cooperative infrared spacecraft

    NASA Astrophysics Data System (ADS)

    Li, Zhengzhou; Ge, Fengzeng; Chen, Wenhao; Shao, Wanxing; Liu, Bing; Cheng, Bei

    2016-09-01

    The issue of feature point mismatching among infrared image sequence would bring big challenge to estimating the relative motion of non-cooperative spacecraft for it couldn't provide the prior knowledge about its geometric structure and motion pattern. The paper introduces particle filter to precisely match the feature points within a desired region predicted by a kinetic equation, and presents a least square estimation-based algorithm to measure the relative rolling motion of non-cooperative spacecraft. The state transition equation and the measurement update equation of non-cooperative spacecraft are represented by establishing its kinetic equations, and then the relative pose measurement is converted to the maximum posteriori probability estimation via assuming the uncertainties about geometric structure and motion pattern as random and time-varying variables. These uncertainties would be interpreted and even solved through continuously measuring the image feature points of the rotating non-cooperative infrared spacecraft. Subsequently, the feature point is matched within a predicted region among sequence infrared image using particle filter algorithm to overcome the position estimation noise caused by the uncertainties of geometric structure and motion pattern. Finally, the position parameters including rotation motion are estimated by means of solving the minimum error of feature point mismatching using least square estimate theory. Both simulated and real infrared image sequences are induced in the experiment to evaluate the performance of the relative rolling estimation, and the experimental data show that the rolling motion estimated by the proposed algorithm is more robust to the feature extraction noise and various rotation speed. Meanwhile, the relative rolling estimation error would increase dramatically with distance and rotation speed increasing.

  13. Modelling of cooperating robotized systems with the use of object-based approach

    NASA Astrophysics Data System (ADS)

    Foit, K.; Gwiazda, A.; Banas, W.; Sekala, A.; Hryniewicz, P.

    2015-11-01

    Today's robotized manufacturing systems are characterized by high efficiency. The emphasis is placed mainly on the simultaneous work of machines. It could manifest in many ways, where the most spectacular one is the cooperation of several robots, during work on the same detail. What's more, recently a dual-arm robots are used that could mimic the manipulative skills of human hands. As a result, it is often hard to deal with the situation, when it is necessary not only to maintain sufficient precision, but also the coordination and proper sequence of movements of individual robots’ arms. The successful completion of this task depends on the individual robot control systems and their respective programmed, but also on the well-functioning communication between robot controllers. A major problem in case of cooperating robots is the possibility of collision between particular links of robots’ kinematic chains. This is not a simple case, because the manufacturers of robotic systems do not disclose the details of the control algorithms, then it is hard to determine such situation. Another problem with cooperation of robots is how to inform the other units about start or completion of part of the task, so that other robots can take further actions. This paper focuses on communication between cooperating robotic units, assuming that every robot is represented by object-based model. This problem requires developing a form of communication protocol that the objects can use for collecting the information about its environment. The approach presented in the paper is not limited to the robots and could be used in a wider range, for example during modelling of the complete workcell or production line.

  14. A state-based approach to trend recognition and failure prediction for the Space Station Freedom

    NASA Technical Reports Server (NTRS)

    Nelson, Kyle S.; Hadden, George D.

    1992-01-01

    A state-based reasoning approach to trend recognition and failure prediction for the Altitude Determination, and Control System (ADCS) of the Space Station Freedom (SSF) is described. The problem domain is characterized by features (e.g., trends and impending failures) that develop over a variety of time spans, anywhere from several minutes to several years. Our state-based reasoning approach, coupled with intelligent data screening, allows features to be tracked as they develop in a time-dependent manner. That is, each state machine has the ability to encode a time frame for the feature it detects. As features are detected, they are recorded and can be used as input to other state machines, creating a hierarchical feature recognition scheme. Furthermore, each machine can operate independently of the others, allowing simultaneous tracking of features. State-based reasoning was implemented in the trend recognition and the prognostic modules of a prototype Space Station Freedom Maintenance and Diagnostic System (SSFMDS) developed at Honeywell's Systems and Research Center.

  15. A knowledge-based machine vision system for space station automation

    NASA Technical Reports Server (NTRS)

    Chipman, Laure J.; Ranganath, H. S.

    1989-01-01

    A simple knowledge-based approach to the recognition of objects in man-made scenes is being developed. Specifically, the system under development is a proposed enhancement to a robot arm for use in the space station laboratory module. The system will take a request from a user to find a specific object, and locate that object by using its camera input and information from a knowledge base describing the scene layout and attributes of the object types included in the scene. In order to use realistic test images in developing the system, researchers are using photographs of actual NASA simulator panels, which provide similar types of scenes to those expected in the space station environment. Figure 1 shows one of these photographs. In traditional approaches to image analysis, the image is transformed step by step into a symbolic representation of the scene. Often the first steps of the transformation are done without any reference to knowledge of the scene or objects. Segmentation of an image into regions generally produces a counterintuitive result in which regions do not correspond to objects in the image. After segmentation, a merging procedure attempts to group regions into meaningful units that will more nearly correspond to objects. Here, researchers avoid segmenting the image as a whole, and instead use a knowledge-directed approach to locate objects in the scene. The knowledge-based approach to scene analysis is described and the categories of knowledge used in the system are discussed.

  16. Station Based Polynomial Modeling of the local ionospheric Vertical Total Electron Content (VTEC) using Particle Filter

    NASA Astrophysics Data System (ADS)

    Erdogan, Eren; Onur Karslioglu, Mahmut; Durmaz, Murat; Aghakarimi, Armin

    2014-05-01

    In this study, particle filter (PF) which is mainly based on the Monte Carlo simulation technique has been carried out for polynomial modeling of the local ionospheric conditions above the selected ground based stations. Less sensitivity to the errors caused by linearization of models and the effect of unknown or unmodeled components in the system model is one of the advantages of the particle filter as compared to the Kalman filter which is commonly used as a recursive filtering method in VTEC modeling. Besides, probability distribution of the system models is not necessarily required to be Gaussian. In this work third order polynomial function has been incorporated into the particle filter implementation to represent the local VTEC distribution. Coefficients of the polynomial model presenting the ionospheric parameters and the receiver inter frequency biases are the unknowns forming the state vector which has been estimated epoch-wise for each ground station. To consider the time varying characteristics of the regional VTEC distribution, dynamics of the state vector parameters changing permanently have been modeled using the first order Gauss-Markov process. In the processing of the particle filtering, multi-variety probability distribution of the state vector through the time has been approximated by means of randomly selected samples and their associated weights. A known drawback of the particle filtering is that the increasing number of the state vector parameters results in an inefficient filter performance and requires more samples to represent the probability distribution of the state vector. Considering the total number of unknown parameters for all ground stations, estimation of these parameters which were inserted into a single state vector has caused the particle filter to produce inefficient results. To solve this problem, the PF implementation has been carried out separately for each ground station at current time epochs. After estimation of unknown

  17. Analysis of local ionospheric variability based on SVD and MDS at low-latitude GNSS stations

    NASA Astrophysics Data System (ADS)

    Dabbakuti, J. R. K. Kumar; Devanaboyina, Venkata Ratnam; Kanchumarthi, S. Ramesh

    2016-06-01

    Investigation of ionospheric anomalies during equatorial and low latitude is of major concern for modeling and global navigation satellite system (GNSS) applications. Total electron content (TEC) varies with the ionospheric conditions, which will lead to the errors in the global positioning system (GPS) measurements. It is therefore a method that is necessary to characterize the ionospheric anomalies for satellite-based navigation systems. In this study, characterization of ionospheric variations based on the singular value decomposition (SVD) and classical multidimensional scaling (MDS) methods was studied. The yearly and daily variations are decomposed from the GPS-TEC, international reference ionosphere (IRI) 2007 and IRI 2012 models TEC over the three low-latitude GNSS stations located at Koneru Lakshmaiah University (KLU-Guntur), Hyderabad and Bangalore, respectively. From the results, it is found that there is a strong correlation between GPS-TEC and IRI models. The correlation coefficient for the first three singular values is more than 0.86. From this, it is possible to reconstruct more than 85 % of the variability contained in global GPS-derived VTEC data (for year 2013) by using only the first three modes. The semiannual variation has maximum value during March-April and September-October and has minimum value during June-July. It is observed that the annual variations have maximum value in summer and minimum value in winter, and the amplitudes decrease with increasing latitude. Further, opposite latitudinal asymmetry among annual and semiannual variations for three GNSS stations is noticed. SVD and MDS methods clearly show time-varying characteristics and the absence of the winter anomaly at low-latitude GNSS stations.

  18. International Space Station as a Base Camp for Exploration Beyond Low Earth Orbit

    NASA Technical Reports Server (NTRS)

    Raftery, Michael; Hoffman, Jeffrey

    2011-01-01

    The idea for using the International Space Station (ISS) as platform for exploration has matured in the past year and the concept continues to gain momentum. ISS provides a robust infrastructure which can be used to test systems and capabilities needed for missions to the Moon, Mars, asteroids and other potential destinations. International cooperation is a critical enabler and ISS has already demonstrated successful management of a large multi-national technical endeavor. Systems and resources needed for expeditions can be aggregated and thoroughly tested at ISS before departure thus providing wide operational flexibility and the best assurance of mission success. A small part of ISS called an Exploration Platform (ISS-EP) can be placed at Earth-Moon Libration point 1 (EML1) providing immediate benefits and flexibility for future exploration missions. We will show how ISS and the ISS-EP can be used to reduce risk and improve the operational flexibility for missions beyond low earth orbit. Life support systems and other technology developed for ISS can be evolved and adapted to the ISS-EP and other exploration spacecraft. New technology, such as electric propulsion and advanced life support systems can be tested and proven at ISS as part of an incremental development program. Commercial companies who are introducing transportation and other services will benefit with opportunities to contribute to the mission since ISS will serve as a focal point for the commercialization of low earth orbit services. Finally, we will show how use of ISS provides immediate benefits to the scientific community because its capabilities are available today and certain critical aspects of exploration missions can be simulated.

  19. International Space Station as a base camp for exploration beyond low Earth orbit

    NASA Astrophysics Data System (ADS)

    Raftery, Michael; Hoffman, Jeffrey

    2013-04-01

    The idea for using the International Space Station (ISS) as a platform for exploration has matured in the past few years and the concept continues to gain momentum. ISS provides a robust infrastructure which can be used to test systems and capabilities needed for missions to the Moon, Mars, asteroids and other potential destinations. International cooperation is a critical enabler and ISS has already demonstrated successful management of a large multi-national technical endeavor. Systems and resources needed for expeditions can be aggregated and thoroughly tested at ISS before departure thus providing wide operational flexibility and the best assurance of mission success. A small part of ISS called an Exploration Platform (ISS-EP) can be placed in cislunar space providing immediate benefits and flexibility for future exploration missions. We will show how ISS and the ISS-EP can be used to reduce risk and improve the operational flexibility for missions beyond low Earth orbit. Life support systems and other technologies developed for ISS can be evolved and adapted to the ISS-EP and other exploration spacecrafts. New technology, such as electric propulsion and advanced life support systems can be tested and proven at ISS as part of an incremental development program. Commercial companies who are introducing transportation and other services will benefit with opportunities to contribute to the mission since ISS will serve as a focal point for the commercialization of low earth orbit services. Finally, we will show how the use of ISS provides immediate benefits to the scientific community because its capabilities are available today and certain critical aspects of exploration missions can be simulated.

  20. Workgroup Report: Base Stations and Wireless Networks—Radiofrequency (RF) Exposures and Health Consequences

    PubMed Central

    Valberg, Peter A.; van Deventer, T. Emilie; Repacholi, Michael H.

    2007-01-01

    Radiofrequency (RF) waves have long been used for different types of information exchange via the airwaves—wireless Morse code, radio, television, and wireless telephony (i.e., construction and operation of telephones or telephonic systems). Increasingly larger numbers of people rely on mobile telephone technology, and health concerns about the associated RF exposure have been raised, particularly because the mobile phone handset operates in close proximity to the human body, and also because large numbers of base station antennas are required to provide widespread availability of service to large populations. The World Health Organization convened an expert workshop to discuss the current state of cellular-telephone health issues, and this article brings together several of the key points that were addressed. The possibility of RF health effects has been investigated in epidemiology studies of cellular telephone users and workers in RF occupations, in experiments with animals exposed to cell-phone RF, and via biophysical consideration of cell-phone RF electric-field intensity and the effect of RF modulation schemes. As summarized here, these separate avenues of scientific investigation provide little support for adverse health effects arising from RF exposure at levels below current international standards. Moreover, radio and television broadcast waves have exposed populations to RF for > 50 years with little evidence of deleterious health consequences. Despite unavoidable uncertainty, current scientific data are consistent with the conclusion that public exposures to permissible RF levels from mobile telephony and base stations are not likely to adversely affect human health. PMID:17431492

  1. Timepix-based radiation environment monitor measurements aboard the International Space Station

    NASA Astrophysics Data System (ADS)

    Stoffle, Nicholas; Pinsky, Lawrence; Kroupa, Martin; Hoang, Son; Idarraga, John; Amberboy, Clif; Rios, Ryan; Hauss, Jessica; Keller, John; Bahadori, Amir; Semones, Edward; Turecek, Daniel; Jakubek, Jan; Vykydal, Zdenek; Pospisil, Stanislav

    2015-05-01

    A number of small, single element radiation detectors, employing the CERN-based Medipix2 Collaboration's Timepix Application Specific Integrated Circuit (ASIC) coupled to a specially modified version of the USB-Lite interface for that ASIC provided by the Institute for Experimental and Applied Physics (IEAP) at the Czech Technical University in Prague, have been developed at the University of Houston and NASA Johnson Space Center. These detectors, officially designated by NASA as Radiation Environment Monitors (REMs), were deployed aboard the International Space Station in late 2012. Six REM units are currently operating on Station Support Computers (SSCs) and returning data on a daily basis. The associated data acquisition software on the SSCs provides both automated data collection and transfer, as well as algorithms to handle adjustment of acquisition rates and recovery and restart of the acquisition software. A suite of ground software analysis tools has been developed to allow rapid analysis of the data and provides a ROOT-based framework for extending data analysis capabilities.

  2. LoRa Mobile-To-Base-Station Channel Characterization in the Antarctic.

    PubMed

    Gaelens, Johnny; Van Torre, Patrick; Verhaevert, Jo; Rogier, Hendrik

    2017-08-18

    Antarctic conditions demand that wireless sensor nodes are operational all year round and that they provide a large communication range of several tens of kilometers. LoRa technology operating in sub-GHz frequency bands implements these wireless links with minimal power consumption. The employed chirp spread spectrum modulation provides a large link budget, combined with the excellent radio-wave propagation characteristics in these bands. In this paper, an experimental wireless link from a mobile vehicle which transmits sensor data to a base station is measured and analyzed in terms of signal-to-noise ratio and packet loss. These measurements confirm the usefulness of LoRa technology for wireless sensor systems in polar regions. By deploying directional antennas at the base station, a range of up to 30 km is covered in case of Line-of-Sight radio propagation in both the 434 and 868 MHz bands. Varying terrain elevation is shown to be the dominating factor influencing the propagation, sometimes causing the Line-of-Sight path to be obstructed. Tropospheric radio propagation effects were not apparent in the measurements.

  3. Workgroup report: base stations and wireless networks-radiofrequency (RF) exposures and health consequences.

    PubMed

    Valberg, Peter A; van Deventer, T Emilie; Repacholi, Michael H

    2007-03-01

    Radiofrequency (RF) waves have long been used for different types of information exchange via the air waves--wireless Morse code, radio, television, and wireless telephone (i.e., construction and operation of telephones or telephone systems). Increasingly larger numbers of people rely on mobile telephone technology, and health concerns about the associated RF exposure have been raised, particularly because the mobile phone handset operates in close proximity to the human body, and also because large numbers of base station antennas are required to provide widespread availability of service to large populations. The World Health Organization convened an expert workshop to discuss the current state of cellular-telephone health issues, and this article brings together several of the key points that were addressed. The possibility of RF health effects has been investigated in epidemiology studies of cellular telephone users and workers in RF occupations, in experiments with animals exposed to cell-phone RF, and via biophysical consideration of cell-phone RF electric-field intensity and the effect of RF modulation schemes. As summarized here, these separate avenues of scientific investigation provide little support for adverse health effects arising from RF exposure at levels below current international standards. Moreover, radio and television broadcast waves have exposed populations to RF for > 50 years with little evidence of deleterious health consequences. Despite unavoidable uncertainty, current scientific data are consistent with the conclusion that public exposures to permissible RF levels from mobile telephone and base stations are not likely to adversely affect human health.

  4. The precautionary principle in the context of mobile phone and base station radiofrequency exposures.

    PubMed

    Dolan, Mike; Rowley, Jack

    2009-09-01

    No health hazard has been established from exposure to radiofrequency fields up to the levels recommended by the International Commission on Non-Ionizing Radiation Protection. However, in response to public concern and the perceived level of scientific uncertainty, there are continuing calls for the application of the precautionary principle to radiofrequency exposures from mobile phones and base stations. We examined the international evolution of calls for precautionary measures in relation to mobile phones and base stations, with particular focus on Australia and the United Kingdom. The precautionary principle is difficult to define, and there is no widespread agreement as to how it should be implemented. However, there is a strong argument that precautionary measures should not be implemented in the absence of reliable scientific data and logical reasoning pointing to a possible health hazard. There is also experimental evidence that precautionary advice may increase public concern. We argue that conservative exposure standards, technical features that minimize unnecessary exposures, ongoing research, regular review of standards, and availability of consumer information make mobile communications inherently precautionary. Commonsense measures can be adopted by individuals, governments, and industry to address public concern while ensuring that mobile networks are developed for the benefit of society.

  5. The Precautionary Principle in the Context of Mobile Phone and Base Station Radiofrequency Exposures

    PubMed Central

    Dolan, Mike; Rowley, Jack

    2009-01-01

    Background No health hazard has been established from exposure to radiofrequency fields up to the levels recommended by the International Commission on Non-Ionizing Radiation Protection. However, in response to public concern and the perceived level of scientific uncertainty, there are continuing calls for the application of the precautionary principle to radiofrequency exposures from mobile phones and base stations. Objective We examined the international evolution of calls for precautionary measures in relation to mobile phones and base stations, with particular focus on Australia and the United Kingdom. Results The precautionary principle is difficult to define, and there is no widespread agreement as to how it should be implemented. However, there is a strong argument that precautionary measures should not be implemented in the absence of reliable scientific data and logical reasoning pointing to a possible health hazard. There is also experimental evidence that precautionary advice may increase public concern. Conclusion We argue that conservative exposure standards, technical features that minimize unnecessary exposures, ongoing research, regular review of standards, and availability of consumer information make mobile communications inherently precautionary. Commonsense measures can be adopted by individuals, governments, and industry to address public concern while ensuring that mobile networks are developed for the benefit of society. PMID:19750093

  6. LoRa Mobile-To-Base-Station Channel Characterization in the Antarctic

    PubMed Central

    Gaelens, Johnny; Van Torre, Patrick; Verhaevert, Jo

    2017-01-01

    Antarctic conditions demand that wireless sensor nodes are operational all year round and that they provide a large communication range of several tens of kilometers. LoRa technology operating in sub-GHz frequency bands implements these wireless links with minimal power consumption. The employed chirp spread spectrum modulation provides a large link budget, combined with the excellent radio-wave propagation characteristics in these bands. In this paper, an experimental wireless link from a mobile vehicle which transmits sensor data to a base station is measured and analyzed in terms of signal-to-noise ratio and packet loss. These measurements confirm the usefulness of LoRa technology for wireless sensor systems in polar regions. By deploying directional antennas at the base station, a range of up to 30 km is covered in case of Line-of-Sight radio propagation in both the 434 and 868 MHz bands. Varying terrain elevation is shown to be the dominating factor influencing the propagation, sometimes causing the Line-of-Sight path to be obstructed. Tropospheric radio propagation effects were not apparent in the measurements. PMID:28820477

  7. Performance of static positioning for medium distances based on data from a virtual reference station and ASG-PL Network

    NASA Astrophysics Data System (ADS)

    Bakula, M.

    The use of a network of reference stations instead of a single reference station allows the modelling of some systematic errors in a region and allows a user to increase the distance between the rover receiver and reference stations. In some countries, GPS reference stations exist and GPS observations are available for users in real-time mode and in post-processing. Observations from several GPS reference stations in a regional network enable modelling spatially-correlated errors and their modelling on an epoch-by-epoch and satellite-by-satellite basis. As a result, observations of a virtual reference station can be created at a rover's approximate position and its observations can be used in the precise baseline positioning of the rover. This paper presents the performance of the static positioning of a rover station, its quality and reliability for two different baselines. Single-baseline and network static solutions are presented and compared. Network solutions are based on data from a virtual reference station (VRS) obtained by the Wasoft/Virtuall software. In both cases, the same strategy of ambiguity resolution was used. These approaches have been tested with the use of 24-hour GPS data from the Polish Active Geodetic Network (ASG-PL). The data from three reference stations with medium-range separation were used in the process of generating VRS data. GPS data of the rover station were divided into 20, 10 and 5-min. sessions with a sampling interval of 5 sec. Practical calculations and analyses of horizontal and vertical accuracy of coordinates clearly show the improvement of static positioning in terms of time observation span and ambiguity reliability.

  8. Comparison of technology-based cooperative learning with technology-based individual learning in enhancing fundamental nursing proficiency.

    PubMed

    Lin, Zu-Chun

    2013-05-01

    The aim of nursing education is to prepare students with critical thinking, high interests in profession and high proficiency in patient care. Cooperative learning promotes team work and encourages knowledge building upon discussion. It has been viewed as one of the most powerful learning methods. Technology has been considered an influential tool in teaching and learning. It assists students in gathering more information to solve the problems and master skills better. The purpose of this study was to compare the effect of technology-based cooperative learning with technology-based individual learning in nursing students' critical thinking in catheterization knowledge gaining, error discovering, skill acquisitions, and overall scores. This study used a pretest-posttest experimental design. Ninety-eight students were assigned randomly to one of two groups. Questionnaires and tests were collected at baseline and after completion of intervention. The results of this study showed that there was no significant difference in related catheterization skill performance. However, the remaining variables differed greatly between the two groups. CONCLUSIONS AND APPLICATIONS: This study's findings guide the researchers and instructors to use technology-based cooperative learning more appropriately. Future research should address the design of the course module and the availability of mobile devices to reach student-centered and learn on the move goals. Copyright © 2011 Elsevier Ltd. All rights reserved.

  9. International Space Station (ISS)

    NASA Image and Video Library

    1997-06-01

    Artist's digital concept of the International Space Station (ISS), a gateway to permanent human presence in space, after all assembly is completed in Year 2003. The Station will be powered by almost an acre of solar panels and have a mass of almost one million pounds. Station modules are being provided by the United States, Russia, Japan, and Europe. Canada is providing a mechanical arm and Canada Hand. Sixteen countries are cooperating to provide a multidisciplinary laboratory, technology test bed, and observatory that will provide an unprecedented undertaking in scientific, technological, and international experimentation.

  10. More than a drop in the bucket: decentralized membrane-based drinking water refill stations in southeast Asia.

    PubMed

    Sima, Laura C; Elimelech, Menachem

    2013-07-16

    Decentralized membrane-based water treatment and refill stations represent a viable and growing business model in Southeast Asia, which rely upon the purchase of water from refill stations by consumers. This feature article discusses these water treatment and refill stations, including the appropriateness of the technology, the suitability of the business models employed, and the long-term environmental and operational sustainability of these systems. We also provide an outlook for the sector, highlighting key technical challenges that need to be addressed in order to improve the capacity of these systems, such that they can become an effective and financially viable solution.

  11. Mass spectrometry based on a coupled Cooper-pair box and nanomechanical resonator system

    NASA Astrophysics Data System (ADS)

    Jiang, Cheng; Chen, Bin; Li, Jin-Jin; Zhu, Ka-Di

    2011-10-01

    Nanomechanical resonators (NRs) with very high frequency have a great potential for mass sensing with unprecedented sensitivity. In this study, we propose a scheme for mass sensing based on the NR capacitively coupled to a Cooper-pair box (CPB) driven by two microwave currents. The accreted mass landing on the resonator can be measured conveniently by tracking the resonance frequency shifts because of mass changes in the signal absorption spectrum. We demonstrate that frequency shifts induced by adsorption of ten 1587 bp DNA molecules can be well resolved in the absorption spectrum. Integration with the CPB enables capacitive readout of the mechanical resonance directly on the chip.

  12. Raising awareness of assistive technology in older adults through a community-based, cooperative extension program.

    PubMed

    Sellers, Debra M; Markham, Melinda Stafford

    2012-01-01

    The Fashion an Easier Lifestyle with Assistive Technology (FELAT) curriculum was developed as a needs-based, community educational program provided through a state Cooperative Extension Service. The overall goal for participants was to raise awareness of assistive technology. Program evaluation included a postassessment and subsequent interview to determine short-term knowledge gain and longer term behavior change. The sample consisted of mainly older, married females. The FELAT program was effective at raising awareness and increasing knowledge of assistive technology, and for many participants, the program acted as a catalyst for planning to or taking action related to assistive technology.

  13. Mass spectrometry based on a coupled Cooper-pair box and nanomechanical resonator system.

    PubMed

    Jiang, Cheng; Chen, Bin; Li, Jin-Jin; Zhu, Ka-Di

    2011-10-31

    Nanomechanical resonators (NRs) with very high frequency have a great potential for mass sensing with unprecedented sensitivity. In this study, we propose a scheme for mass sensing based on the NR capacitively coupled to a Cooper-pair box (CPB) driven by two microwave currents. The accreted mass landing on the resonator can be measured conveniently by tracking the resonance frequency shifts because of mass changes in the signal absorption spectrum. We demonstrate that frequency shifts induced by adsorption of ten 1587 bp DNA molecules can be well resolved in the absorption spectrum. Integration with the CPB enables capacitive readout of the mechanical resonance directly on the chip.

  14. Mass spectrometry based on a coupled Cooper-pair box and nanomechanical resonator system

    PubMed Central

    2011-01-01

    Nanomechanical resonators (NRs) with very high frequency have a great potential for mass sensing with unprecedented sensitivity. In this study, we propose a scheme for mass sensing based on the NR capacitively coupled to a Cooper-pair box (CPB) driven by two microwave currents. The accreted mass landing on the resonator can be measured conveniently by tracking the resonance frequency shifts because of mass changes in the signal absorption spectrum. We demonstrate that frequency shifts induced by adsorption of ten 1587 bp DNA molecules can be well resolved in the absorption spectrum. Integration with the CPB enables capacitive readout of the mechanical resonance directly on the chip. PMID:22039926

  15. Fuzzy variable impedance control based on stiffness identification for human-robot cooperation

    NASA Astrophysics Data System (ADS)

    Mao, Dachao; Yang, Wenlong; Du, Zhijiang

    2017-06-01

    This paper presents a dynamic fuzzy variable impedance control algorithm for human-robot cooperation. In order to estimate the intention of human for co-manipulation, a fuzzy inference system is set up to adjust the impedance parameter. Aiming at regulating the output fuzzy universe based on the human arm’s stiffness, an online stiffness identification method is developed. A drag interaction task is conducted on a 5-DOF robot with variable impedance control. Experimental results demonstrate that the proposed algorithm is superior.

  16. Latitudinal GRBR-TEC estimation in Southeast Asia region based on the two-station method

    NASA Astrophysics Data System (ADS)

    Watthanasangmechai, Kornyanat; Yamamoto, Mamoru; Saito, Akinori; Tsugawa, Takuya; Yokoyama, Tatsuhiro; Supnithi, Pornchai; Yatini, Clara Yono

    2014-10-01

    Total electron content (TEC) is an important parameter for revealing latitudinal ionospheric structures, such as the equatorial ionization anomaly (EIA) in Southeast Asia. Understanding the EIA is beneficial for studying equatorial spread F. To reveal the structures, the absolute TEC as a function of latitude must be accurately determined. In early 2012, we expanded a GNU Radio Beacon Receiver (GRBR) network to provide latitudinal coverage in the Thailand-Indonesia sector. We employed the GRBR network to receive VHF and UHF signals from polar low-Earth-orbit satellites. The TEC offset is an unknown parameter in the absolute TEC estimation process. We propose a new technique based on the two-station method to estimate the offset for the latitudinal TEC estimation, and it works better than the original method for a sparse network. The TEC estimation system requires two iterations to minimize the root-mean-square error (RMSE). Once the RMSE reaches the global minimum, the absolute TECs are estimated simultaneously over five GRBR stations. GPS-TECs from local stations are used as the initial guess of the offset estimation. The height of the ionospheric pierce point is determined from the ionosonde hmF2. As a result, the latitudinal GRBR-TEC was successfully estimated from the polar orbit satellites. The two EIA humps were clearly captured by the GRBR-TEC. The result was well verified with the TEC reconstructed from the C/NOFS density data and the ionosonde bottomside data. This is a significant step showing that the GRBR is a useful tool for the study of low-latitude ionospheric features.

  17. Robotic assembly and maintenance of future space stations based on the ISS mission operations experience

    NASA Astrophysics Data System (ADS)

    Rembala, Richard; Ower, Cameron

    2009-10-01

    MDA has provided 25 years of real-time engineering support to Shuttle (Canadarm) and ISS (Canadarm2) robotic operations beginning with the second shuttle flight STS-2 in 1981. In this capacity, our engineering support teams have become familiar with the evolution of mission planning and flight support practices for robotic assembly and support operations at mission control. This paper presents observations on existing practices and ideas to achieve reduced operational overhead to present programs. It also identifies areas where robotic assembly and maintenance of future space stations and space-based facilities could be accomplished more effectively and efficiently. Specifically, our experience shows that past and current space Shuttle and ISS assembly and maintenance operations have used the approach of extensive preflight mission planning and training to prepare the flight crews for the entire mission. This has been driven by the overall communication latency between the earth and remote location of the space station/vehicle as well as the lack of consistent robotic and interface standards. While the early Shuttle and ISS architectures included robotics, their eventual benefits on the overall assembly and maintenance operations could have been greater through incorporating them as a major design driver from the beginning of the system design. Lessons learned from the ISS highlight the potential benefits of real-time health monitoring systems, consistent standards for robotic interfaces and procedures and automated script-driven ground control in future space station assembly and logistics architectures. In addition, advances in computer vision systems and remote operation, supervised autonomous command and control systems offer the potential to adjust the balance between assembly and maintenance tasks performed using extra vehicular activity (EVA), extra vehicular robotics (EVR) and EVR controlled from the ground, offloading the EVA astronaut and even the robotic

  18. Robust and Cooperative Image-Based Visual Servoing System Using a Redundant Architecture

    PubMed Central

    Garcia-Aracil, Nicolas; Perez-Vidal, Carlos; Sabater, Jose Maria; Morales, Ricardo; Badesa, Francisco J.

    2011-01-01

    The reliability and robustness of image-based visual servoing systems is still unsolved by the moment. In order to address this issue, a redundant and cooperative 2D visual servoing system based on the information provided by two cameras in eye-in-hand/eye-to-hand configurations is proposed. Its control law has been defined to assure that the whole system is stable if each subsystem is stable and to allow avoiding typical problems of image-based visual servoing systems like task singularities, features extraction errors, disappearance of image features, local minima, etc. Experimental results with an industrial robot manipulator based on Schunk modular motors to demonstrate the stability, performance and robustness of the proposed system are presented. PMID:22247698

  19. Robust and cooperative image-based visual servoing system using a redundant architecture.

    PubMed

    Garcia-Aracil, Nicolas; Perez-Vidal, Carlos; Sabater, Jose Maria; Morales, Ricardo; Badesa, Francisco J

    2011-01-01

    The reliability and robustness of image-based visual servoing systems is still unsolved by the moment. In order to address this issue, a redundant and cooperative 2D visual servoing system based on the information provided by two cameras in eye-in-hand/eye-to-hand configurations is proposed. Its control law has been defined to assure that the whole system is stable if each subsystem is stable and to allow avoiding typical problems of image-based visual servoing systems like task singularities, features extraction errors, disappearance of image features, local minima, etc. Experimental results with an industrial robot manipulator based on Schunk modular motors to demonstrate the stability, performance and robustness of the proposed system are presented.

  20. Reputation-Based Trust for a Cooperative, Agent-Based Backup Protection Scheme for Power Networks

    DTIC Science & Technology

    2010-03-01

    The transmission systems in each grid are then linked to distribution systems at power substations . The voltage is gradually stepped down to lower...protection mechanisms such as intrusion detection systems and firewalls. This thesis shows that cooperative information sharing produces improved decision...power systems [40]. The first term is voltage . Voltage (V) refers to the difference in electric potential and can be expressed as one Joule of

  1. A soft-hard combination-based cooperative spectrum sensing scheme for cognitive radio networks.

    PubMed

    Do, Nhu Tri; An, Beongku

    2015-02-13

    In this paper we propose a soft-hard combination scheme, called SHC scheme, for cooperative spectrum sensing in cognitive radio networks. The SHC scheme deploys a cluster based network in which Likelihood Ratio Test (LRT)-based soft combination is applied at each cluster, and weighted decision fusion rule-based hard combination is utilized at the fusion center. The novelties of the SHC scheme are as follows: the structure of the SHC scheme reduces the complexity of cooperative detection which is an inherent limitation of soft combination schemes. By using the LRT, we can detect primary signals in a low signal-to-noise ratio regime (around an average of -15 dB). In addition, the computational complexity of the LRT is reduced since we derive the closed-form expression of the probability density function of LRT value. The SHC scheme also takes into account the different effects of large scale fading on different users in the wide area network. The simulation results show that the SHC scheme not only provides the better sensing performance compared to the conventional hard combination schemes, but also reduces sensing overhead in terms of reporting time compared to the conventional soft combination scheme using the LRT.

  2. Distributed Fault Detection Based on Credibility and Cooperation for WSNs in Smart Grids

    PubMed Central

    Shao, Sujie; Guo, Shaoyong; Qiu, Xuesong

    2017-01-01

    Due to the increasingly important role in monitoring and data collection that sensors play, accurate and timely fault detection is a key issue for wireless sensor networks (WSNs) in smart grids. This paper presents a novel distributed fault detection mechanism for WSNs based on credibility and cooperation. Firstly, a reasonable credibility model of a sensor is established to identify any suspicious status of the sensor according to its own temporal data correlation. Based on the credibility model, the suspicious sensor is then chosen to launch fault diagnosis requests. Secondly, the sending time of fault diagnosis request is discussed to avoid the transmission overhead brought about by unnecessary diagnosis requests and improve the efficiency of fault detection based on neighbor cooperation. The diagnosis reply of a neighbor sensor is analyzed according to its own status. Finally, to further improve the accuracy of fault detection, the diagnosis results of neighbors are divided into several classifications to judge the fault status of the sensors which launch the fault diagnosis requests. Simulation results show that this novel mechanism can achieve high fault detection ratio with a small number of fault diagnoses and low data congestion probability. PMID:28452925

  3. Distributed Fault Detection Based on Credibility and Cooperation for WSNs in Smart Grids.

    PubMed

    Shao, Sujie; Guo, Shaoyong; Qiu, Xuesong

    2017-04-28

    Due to the increasingly important role in monitoring and data collection that sensors play, accurate and timely fault detection is a key issue for wireless sensor networks (WSNs) in smart grids. This paper presents a novel distributed fault detection mechanism for WSNs based on credibility and cooperation. Firstly, a reasonable credibility model of a sensor is established to identify any suspicious status of the sensor according to its own temporal data correlation. Based on the credibility model, the suspicious sensor is then chosen to launch fault diagnosis requests. Secondly, the sending time of fault diagnosis request is discussed to avoid the transmission overhead brought about by unnecessary diagnosis requests and improve the efficiency of fault detection based on neighbor cooperation. The diagnosis reply of a neighbor sensor is analyzed according to its own status. Finally, to further improve the accuracy of fault detection, the diagnosis results of neighbors are divided into several classifications to judge the fault status of the sensors which launch the fault diagnosis requests. Simulation results show that this novel mechanism can achieve high fault detection ratio with a small number of fault diagnoses and low data congestion probability.

  4. Role of the right inferior frontal gyrus in turn-based cooperation and competition: A near-infrared spectroscopy study.

    PubMed

    Liu, Tao; Saito, Hirofumi; Oi, Misato

    2015-10-01

    Interpersonal interaction can be classified into two types: concurrent and turn-based interaction, requiring synchronized body-movement and complementary behaviors across persons, respectively. To examine the neural mechanism of turn-based interaction, we simultaneously measured paired participants activations in their bilateral inferior frontal gyrus (IFG) and the bilateral inferior parietal lobule (IPL) in a turn-taking game using near-infrared spectroscopy (NIRS). Pairs of participants were assigned to either one of two roles (game builder and the partner) in the game. The builder's task was to make a copy of a target disk-pattern by placing disks on a monitor, while the partner's task was to aid the builder in his/her goal (cooperation condition) or to obstruct it (competition condition). The builder always took the initial move and the partner followed. The NIRS data demonstrated an interaction of role (builder vs. partner) by task-type (cooperation vs. competition) in the right IFG. The builder in the cooperation condition showed higher activation than the cooperator, but the same builder in the competition condition showed lower activation than in the cooperation condition. The activations in the competitor-builder pairs showed positive correlation between their right IFG, but the activations in the cooperator-builder pairs did not. These results suggest that the builder's activation in the right IFG is reduced/increased in the context of interacting with a cooperative/competitive partner. Also, the competitor may actively trace the builder's disk manipulation, leading to deeper mind-set synchronization in the competition condition, while the cooperator may passively follow the builder's move, leading to shallower mind-set synchronization in the cooperation condition.

  5. International Space Station-Based Electromagnetic Launcher for Space Science Payloads

    NASA Technical Reports Server (NTRS)

    Jones, Ross M.

    2013-01-01

    A method was developed of lowering the cost of planetary exploration missions by using an electromagnetic propulsion/launcher, rather than a chemical-fueled rocket for propulsion. An electromagnetic launcher (EML) based at the International Space Station (ISS) would be used to launch small science payloads to the Moon and near Earth asteroids (NEAs) for the science and exploration missions. An ISS-based electromagnetic launcher could also inject science payloads into orbits around the Earth and perhaps to Mars. The EML would replace rocket technology for certain missions. The EML is a high-energy system that uses electricity rather than propellant to accelerate payloads to high velocities. The most common type of EML is the rail gun. Other types are possible, e.g., a coil gun, also known as a Gauss gun or mass driver. The EML could also "drop" science payloads into the Earth's upper

  6. Risk-based Inspection Guide for the Susquehanna Station HPCI system

    SciTech Connect

    Travis, R; Higgins, J; Gunther, W; Shier, W

    1992-11-01

    The High Pressure Coolant Injection (HPCI) system has been examined from a risk perspective. A system Risk-based Inspection Guide (S-RIG) has been developed as an aid to HPCI system inspections at the Susquehanna Steam Electric Station (SSES) which is operated by Pennsylvania Power & Light (PP&L). Included in this S-RIG is a discussion of the role of HPCI in mitigating accidents and a presentation of PRA-based failure modes which could prevent proper operation of the system. The S-RIG uses industry operating experience, including plant-specific illustrative examples, to augment the basic PRA failure modes. It is designed to be used as a reference for both routine inspections and the evaluation of the significance of component failures.

  7. International Space Station (ISS)

    NASA Image and Video Library

    1995-04-17

    International Cooperation Phase III: A Space Shuttle docked to the International Space Station (ISS) in this computer generated representation of the ISS in its completed and fully operational state with elements from the U.S., Europe, Canada, Japan, and Russia.

  8. International Space Station (ISS)

    NASA Image and Video Library

    1995-07-11

    Artist's concept for Phase III of the International Space Station (ISS) as shown here in its completed and fully operational state with elements from the United States, Europe, Canada, Japan, and Russia. Sixteen countries are cooperating to provide a multidisciplinary laboratory, technology test bed, and observatory that will provide an unprecedented undertaking in scientific, technological, and international experimentation.

  9. Cooperative robotic sentry vehicles

    NASA Astrophysics Data System (ADS)

    Feddema, John T.; Lewis, Christopher L.; Klarer, Paul; Eisler, G. R.; Caprihan, Rahul

    1999-08-01

    As part of a project for the Defense Advanced Research Projects Agency, Sandia National Laboratories' Intelligent Systems and Robotics Center is developing and testing the feasibility of a cooperative team of robotic sentry vehicles to guard a perimeter and to perform a surround task. This paper describes on-going activities in the development of these robotic sentry vehicles. To date, we have developed a robotic perimeter detection system which consists of eight 'Roving All Terrain Lunar Explorer Rovers' (RATLER), a laptop-based base-station, and several Miniature Intrusion Detection Sensors (MIDS). A radio frequency receiver on each of the RATLER vehicles alerts the sentry vehicles of alarms from the hidden MIDS. When an alarm is received, each vehicle decides whether it should investigate the alarm based on the proximity of itself and the other vehicles to the alarm. As one vehicle attends an alarm, the other vehicles adjust their position around the perimeter to better prepare for another alarm. For the surround task, both potential field and A* search path planners have been added to the base-station and vehicles. At the base-station, the operator specifies goal and exclusion regions on a GIS map. The path planner generates vehicles paths that are previewed by the operator. Once the operator has validated the path, the appropriate information is downloaded t the vehicles. For the potential field path planner, the polygons and line segments that represent the obstacles and goals are downloaded to the vehicles, instead of the simulated paths. On board the vehicles, the same potential field path planner generates the path except that it uses the true location of itself and the nearest neighboring vehicle. For the A* path planner, the actual path is downloaded to the vehicles because of limited on-board computational power.

  10. Free-Suspension Residual Flexibility Testing of Space Station Pathfinder: Comparison to Fixed-Base Results

    NASA Technical Reports Server (NTRS)

    Tinker, Michael L.

    1998-01-01

    Application of the free-suspension residual flexibility modal test method to the International Space Station Pathfinder structure is described. The Pathfinder, a large structure of the general size and weight of Space Station module elements, was also tested in a large fixed-base fixture to simulate Shuttle Orbiter payload constraints. After correlation of the Pathfinder finite element model to residual flexibility test data, the model was coupled to a fixture model, and constrained modes and frequencies were compared to fixed-base test. modes. The residual flexibility model compared very favorably to results of the fixed-base test. This is the first known direct comparison of free-suspension residual flexibility and fixed-base test results for a large structure. The model correlation approach used by the author for residual flexibility data is presented. Frequency response functions (FRF) for the regions of the structure that interface with the environment (a test fixture or another structure) are shown to be the primary tools for model correlation that distinguish or characterize the residual flexibility approach. A number of critical issues related to use of the structure interface FRF for correlating the model are then identified and discussed, including (1) the requirement of prominent stiffness lines, (2) overcoming problems with measurement noise which makes the antiresonances or minima in the functions difficult to identify, and (3) the use of interface stiffness and lumped mass perturbations to bring the analytical responses into agreement with test data. It is shown that good comparison of analytical-to-experimental FRF is the key to obtaining good agreement of the residual flexibility values.

  11. Space Station Needs, Attributes and Architectural Options. Contractor orientation briefings

    NASA Technical Reports Server (NTRS)

    1983-01-01

    Requirements are considered for user missions involving life sciences; astrophysics, environmental observation; Earth and planetary exploration; materials processing; Spacelab payloads; technology development; and communications are analyzed. Plans to exchange data with potential cooperating nations and ESA are reviewed. The capability of the space shuttle to support space station activities are discussed. The status of the OAST space station technology study, conceptual architectures for a space station, elements of the space-based infrastructure, and the use of the shuttle external tank are also considered.

  12. Simple Random Sampling-Based Probe Station Selection for Fault Detection in Wireless Sensor Networks

    PubMed Central

    Huang, Rimao; Qiu, Xuesong; Rui, Lanlan

    2011-01-01

    Fault detection for wireless sensor networks (WSNs) has been studied intensively in recent years. Most existing works statically choose the manager nodes as probe stations and probe the network at a fixed frequency. This straightforward solution leads however to several deficiencies. Firstly, by only assigning the fault detection task to the manager node the whole network is out of balance, and this quickly overloads the already heavily burdened manager node, which in turn ultimately shortens the lifetime of the whole network. Secondly, probing with a fixed frequency often generates too much useless network traffic, which results in a waste of the limited network energy. Thirdly, the traditional algorithm for choosing a probing node is too complicated to be used in energy-critical wireless sensor networks. In this paper, we study the distribution characters of the fault nodes in wireless sensor networks, validate the Pareto principle that a small number of clusters contain most of the faults. We then present a Simple Random Sampling-based algorithm to dynamic choose sensor nodes as probe stations. A dynamic adjusting rule for probing frequency is also proposed to reduce the number of useless probing packets. The simulation experiments demonstrate that the algorithm and adjusting rule we present can effectively prolong the lifetime of a wireless sensor network without decreasing the fault detected rate. PMID:22163789

  13. Simple random sampling-based probe station selection for fault detection in wireless sensor networks.

    PubMed

    Huang, Rimao; Qiu, Xuesong; Rui, Lanlan

    2011-01-01

    Fault detection for wireless sensor networks (WSNs) has been studied intensively in recent years. Most existing works statically choose the manager nodes as probe stations and probe the network at a fixed frequency. This straightforward solution leads however to several deficiencies. Firstly, by only assigning the fault detection task to the manager node the whole network is out of balance, and this quickly overloads the already heavily burdened manager node, which in turn ultimately shortens the lifetime of the whole network. Secondly, probing with a fixed frequency often generates too much useless network traffic, which results in a waste of the limited network energy. Thirdly, the traditional algorithm for choosing a probing node is too complicated to be used in energy-critical wireless sensor networks. In this paper, we study the distribution characters of the fault nodes in wireless sensor networks, validate the Pareto principle that a small number of clusters contain most of the faults. We then present a Simple Random Sampling-based algorithm to dynamic choose sensor nodes as probe stations. A dynamic adjusting rule for probing frequency is also proposed to reduce the number of useless probing packets. The simulation experiments demonstrate that the algorithm and adjusting rule we present can effectively prolong the lifetime of a wireless sensor network without decreasing the fault detected rate.

  14. Design and Development of a CPCI-Based Electronics Package for Space Station Experiments

    NASA Technical Reports Server (NTRS)

    Kolacz, John S.; Clapper, Randy S.; Wade, Raymond P.

    2006-01-01

    The NASA John H. Glenn Research Center is developing a Compact-PCI (CPCI) based electronics package for controlling space experiment hardware on the International Space Station. Goals of this effort include an easily modified, modular design that allows for changes in experiment requirements. Unique aspects of the experiment package include a flexible circuit used for internal interconnections and a separate enclosure (box in a box) for controlling 1 kW of power for experiment fuel heating requirements. This electronics package was developed as part of the FEANICS (Flow Enclosure Accommodating Novel Investigations in Combustion of Solids) mini-facility which is part of the Fluids and Combustion Facility s Combustion Integrated Rack (CIR). The CIR will be the platform for future microgravity combustion experiments and will reside on the Destiny Module of the International Space Station (ISS). The FEANICS mini-facility will be the primary means for conducting solid fuel combustion experiments in the CIR on ISS. The main focus of many of these solid combustion experiments will be to conduct applied scientific investigations in fire-safety to support NASA s future space missions. A description of the electronics package and the results of functional testing are the subjects of this report. The report concludes that the use of innovative packaging methods combined with readily available COTS hardware can provide a modular electronics package which is easily modified for changing experiment requirements.

  15. Graph theoretic framework based cooperative control and estimation of multiple UAVs for target tracking

    NASA Astrophysics Data System (ADS)

    Ahmed, Mousumi

    Designing the control technique for nonlinear dynamic systems is a significant challenge. Approaches to designing a nonlinear controller are studied and an extensive study on backstepping based technique is performed in this research with the purpose of tracking a moving target autonomously. Our main motivation is to explore the controller for cooperative and coordinating unmanned vehicles in a target tracking application. To start with, a general theoretical framework for target tracking is studied and a controller in three dimensional environment for a single UAV is designed. This research is primarily focused on finding a generalized method which can be applied to track almost any reference trajectory. The backstepping technique is employed to derive the controller for a simplified UAV kinematic model. This controller can compute three autopilot modes i.e. velocity, ground heading (or course angle), and flight path angle for tracking the unmanned vehicle. Numerical implementation is performed in MATLAB with the assumption of having perfect and full state information of the target to investigate the accuracy of the proposed controller. This controller is then frozen for the multi-vehicle problem. Distributed or decentralized cooperative control is discussed in the context of multi-agent systems. A consensus based cooperative control is studied; such consensus based control problem can be viewed from the algebraic graph theory concepts. The communication structure between the UAVs is represented by the dynamic graph where UAVs are represented by the nodes and the communication links are represented by the edges. The previously designed controller is augmented to account for the group to obtain consensus based on their communication. A theoretical development of the controller for the cooperative group of UAVs is presented and the simulation results for different communication topologies are shown. This research also investigates the cases where the communication

  16. 47 CFR 0.434 - Data bases and lists of authorized broadcast stations and pending broadcast applications.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 1 2011-10-01 2011-10-01 false Data bases and lists of authorized broadcast... Commission § 0.434 Data bases and lists of authorized broadcast stations and pending broadcast applications. Periodically the FCC makes available copies of its data bases and lists containing information about...

  17. 47 CFR 0.434 - Data bases and lists of authorized broadcast stations and pending broadcast applications.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 1 2014-10-01 2014-10-01 false Data bases and lists of authorized broadcast... Commission § 0.434 Data bases and lists of authorized broadcast stations and pending broadcast applications. Periodically the FCC makes available copies of its data bases and lists containing information about...

  18. 47 CFR 0.434 - Data bases and lists of authorized broadcast stations and pending broadcast applications.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 1 2013-10-01 2013-10-01 false Data bases and lists of authorized broadcast... Commission § 0.434 Data bases and lists of authorized broadcast stations and pending broadcast applications. Periodically the FCC makes available copies of its data bases and lists containing information about...

  19. 47 CFR 0.434 - Data bases and lists of authorized broadcast stations and pending broadcast applications.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 1 2012-10-01 2012-10-01 false Data bases and lists of authorized broadcast... Commission § 0.434 Data bases and lists of authorized broadcast stations and pending broadcast applications. Periodically the FCC makes available copies of its data bases and lists containing information about authorized...

  20. MAS-Based Cooperative Control for Biotechnological Process-A Case Study

    NASA Astrophysics Data System (ADS)

    Choinski, Dariusz; Metzger, Mieczyslaw; Nocon, Witold

    The MAS-based control seems to be better suited for manufacturing control because of its discrete event character. Nevertheless, for continuous industrial processes the MAS-based control can be also very attractive. In this paper, a synthesis of the MAS-based control system for the continuous process is presented. A biological reactor is controlled using respirometric approach. In this approach, both standard control loops and additional experiments are performed to obtain measurements not available on-line. Therefore, the system consists of different control agents being able to cooperate or to inhibit each other in order to achieve the appropriate goals. A case study experiments are realized using an experimental wastewater treatment pilot plant.

  1. A monocular vision system based on cooperative targets detection for aircraft pose measurement

    NASA Astrophysics Data System (ADS)

    Wang, Zhenyu; Wang, Yanyun; Cheng, Wei; Chen, Tao; Zhou, Hui

    2017-08-01

    In this paper, a monocular vision measurement system based on cooperative targets detection is proposed, which can capture the three-dimensional information of objects by recognizing the checkerboard target and calculating of the feature points. The aircraft pose measurement is an important problem for aircraft’s monitoring and control. Monocular vision system has a good performance in the range of meter. This paper proposes an algorithm based on coplanar rectangular feature to determine the unique solution of distance and angle. A continuous frame detection method is presented to solve the problem of corners’ transition caused by symmetry of the targets. Besides, a displacement table test system based on three-dimensional precision and measurement system human-computer interaction software has been built. Experiment result shows that it has a precision of 2mm in the range of 300mm to 1000mm, which can meet the requirement of the position measurement in the aircraft cabin.

  2. Cooperative Localization for Multi-AUVs Based on GM-PHD Filters and Information Entropy Theory.

    PubMed

    Zhang, Lichuan; Wang, Tonghao; Zhang, Feihu; Xu, Demin

    2017-10-08

    Cooperative localization (CL) is considered a promising method for underwater localization with respect to multiple autonomous underwater vehicles (multi-AUVs). In this paper, we proposed a CL algorithm based on information entropy theory and the probability hypothesis density (PHD) filter, aiming to enhance the global localization accuracy of the follower. In the proposed framework, the follower carries lower cost navigation systems, whereas the leaders carry better ones. Meanwhile, the leaders acquire the followers' observations, including both measurements and clutter. Then, the PHD filters are utilized on the leaders and the results are communicated to the followers. The followers then perform weighted summation based on all received messages and obtain a final positioning result. Based on the information entropy theory and the PHD filter, the follower is able to acquire a precise knowledge of its position.

  3. A WAVCIS Based Ocean Observing Station to Provide Hydrodynamic Data off Eglin Air Force Base, Fort Walton, Florida, USA

    DTIC Science & Technology

    2010-06-01

    longer active (yellow dots in Fig. 1). For this project, the CSI FTW station (see Fig. 2) was deployed offshore, off a 91.4 m tall meteorological tower...from the station along with meteorological data from a nearby NOAA station, are discussed in this paper. The Florida observation station (CSI FTW ...a Campbell CR23X Data logger which was housed inside the surface buoy. Field measurements from the CSI FTW station included wave height, wave

  4. Analysis of the effect of mobile phone base station antenna loading on localized SAR and its consequences for measurements.

    PubMed

    Hansson, Björn; Thors, Björn; Törnevik, Christer

    2011-12-01

    In this work, the effect of antenna element loading on the localized specific absorption rate (SAR) has been analyzed for base station antennas. The analysis was conducted in order to determine whether localized SAR measurements of large multi-element base station antennas can be conducted using standardized procedures and commercially available equipment. More specifically, it was investigated if the antenna shifting measurement procedure, specified in the European base station exposure assessment standard EN 50383, will produce accurate localized SAR results for base station antennas larger than the specified measurement phantom. The obtained results show that SAR accuracy is affected by the presence of lossy material within distances of one wavelength from the tested antennas as a consequence of coupling and redistribution of transmitted power among the antenna elements. It was also found that the existing standardized phantom is not optimal for SAR measurements of large base station antennas. A new methodology is instead proposed based on a larger, box-shaped, whole-body phantom.

  5. Autonomous robotic capture of non-cooperative target by adaptive extended Kalman filter based visual servo

    NASA Astrophysics Data System (ADS)

    Dong, Gangqi; Zhu, Zheng H.

    2016-05-01

    This paper presents a real-time, vision-based algorithm for the pose and motion estimation of non-cooperative targets and its application in visual servo robotic manipulator to perform autonomous capture. A hybrid approach of adaptive extended Kalman filter and photogrammetry is developed for the real-time pose and motion estimation of non-cooperative targets. Based on the pose and motion estimates, the desired pose and trajectory of end-effector is defined and the corresponding desired joint angles of the robotic manipulator are derived by inverse kinematics. A close-loop visual servo control scheme is then developed for the robotic manipulator to track, approach and capture the target. Validating experiments are designed and performed on a custom-built six degrees of freedom robotic manipulator with an eye-in-hand configuration. The experimental results demonstrate the feasibility, effectiveness and robustness of the proposed adaptive extended Kalman filter enabled pose and motion estimation and visual servo strategy.

  6. An Accurate Non-Cooperative Method for Measuring Textureless Spherical Target Based on Calibrated Lasers.

    PubMed

    Wang, Fei; Dong, Hang; Chen, Yanan; Zheng, Nanning

    2016-12-09

    Strong demands for accurate non-cooperative target measurement have been arising recently for the tasks of assembling and capturing. Spherical objects are one of the most common targets in these applications. However, the performance of the traditional vision-based reconstruction method was limited for practical use when handling poorly-textured targets. In this paper, we propose a novel multi-sensor fusion system for measuring and reconstructing textureless non-cooperative spherical targets. Our system consists of four simple lasers and a visual camera. This paper presents a complete framework of estimating the geometric parameters of textureless spherical targets: (1) an approach to calibrate the extrinsic parameters between a camera and simple lasers; and (2) a method to reconstruct the 3D position of the laser spots on the target surface and achieve the refined results via an optimized scheme. The experiment results show that our proposed calibration method can obtain a fine calibration result, which is comparable to the state-of-the-art LRF-based methods, and our calibrated system can estimate the geometric parameters with high accuracy in real time.

  7. Robust Feature Selection from Microarray Data Based on Cooperative Game Theory and Qualitative Mutual Information.

    PubMed

    Mortazavi, Atiyeh; Moattar, Mohammad Hossein

    2016-01-01

    High dimensionality of microarray data sets may lead to low efficiency and overfitting. In this paper, a multiphase cooperative game theoretic feature selection approach is proposed for microarray data classification. In the first phase, due to high dimension of microarray data sets, the features are reduced using one of the two filter-based feature selection methods, namely, mutual information and Fisher ratio. In the second phase, Shapley index is used to evaluate the power of each feature. The main innovation of the proposed approach is to employ Qualitative Mutual Information (QMI) for this purpose. The idea of Qualitative Mutual Information causes the selected features to have more stability and this stability helps to deal with the problem of data imbalance and scarcity. In the third phase, a forward selection scheme is applied which uses a scoring function to weight each feature. The performance of the proposed method is compared with other popular feature selection algorithms such as Fisher ratio, minimum redundancy maximum relevance, and previous works on cooperative game based feature selection. The average classification accuracy on eleven microarray data sets shows that the proposed method improves both average accuracy and average stability compared to other approaches.

  8. An Accurate Non-Cooperative Method for Measuring Textureless Spherical Target Based on Calibrated Lasers

    PubMed Central

    Wang, Fei; Dong, Hang; Chen, Yanan; Zheng, Nanning

    2016-01-01

    Strong demands for accurate non-cooperative target measurement have been arising recently for the tasks of assembling and capturing. Spherical objects are one of the most common targets in these applications. However, the performance of the traditional vision-based reconstruction method was limited for practical use when handling poorly-textured targets. In this paper, we propose a novel multi-sensor fusion system for measuring and reconstructing textureless non-cooperative spherical targets. Our system consists of four simple lasers and a visual camera. This paper presents a complete framework of estimating the geometric parameters of textureless spherical targets: (1) an approach to calibrate the extrinsic parameters between a camera and simple lasers; and (2) a method to reconstruct the 3D position of the laser spots on the target surface and achieve the refined results via an optimized scheme. The experiment results show that our proposed calibration method can obtain a fine calibration result, which is comparable to the state-of-the-art LRF-based methods, and our calibrated system can estimate the geometric parameters with high accuracy in real time. PMID:27941705

  9. Individual wealth-based selection supports cooperation in spatial public goods games.

    PubMed

    Chen, Xiaojie; Szolnoki, Attila

    2016-09-06

    In a social dilemma game group members are allowed to decide if they contribute to the joint venture or not. As a consequence, defectors, who do not invest but only enjoy the mutual benefit, prevail and the system evolves onto the tragedy of the common state. This unfortunate scenario can be avoided if participation is not obligatory but only happens with a given probability. But what if we also consider a player's individual wealth when to decide about participation? To address this issue we propose a model in which the probabilistic participation in the public goods game is combined with a conditional investment mode that is based on individual wealth: if a player's wealth exceeds a threshold value then it is qualified and can participate in the joint venture. Otherwise, the participation is forbidden in the investment interactions. We show that if only probabilistic participation is considered, spatially structured populations cannot support cooperation better than well-mixed populations where full defection state can also be avoided for small participation probabilities. By adding the wealth-based criterion of participation, however, structured populations are capable to augment network reciprocity relevantly and allow cooperator strategy to dominate in a broader parameter interval.

  10. Individual wealth-based selection supports cooperation in spatial public goods games

    NASA Astrophysics Data System (ADS)

    Chen, Xiaojie; Szolnoki, Attila

    2016-09-01

    In a social dilemma game group members are allowed to decide if they contribute to the joint venture or not. As a consequence, defectors, who do not invest but only enjoy the mutual benefit, prevail and the system evolves onto the tragedy of the common state. This unfortunate scenario can be avoided if participation is not obligatory but only happens with a given probability. But what if we also consider a player’s individual wealth when to decide about participation? To address this issue we propose a model in which the probabilistic participation in the public goods game is combined with a conditional investment mode that is based on individual wealth: if a player’s wealth exceeds a threshold value then it is qualified and can participate in the joint venture. Otherwise, the participation is forbidden in the investment interactions. We show that if only probabilistic participation is considered, spatially structured populations cannot support cooperation better than well-mixed populations where full defection state can also be avoided for small participation probabilities. By adding the wealth-based criterion of participation, however, structured populations are capable to augment network reciprocity relevantly and allow cooperator strategy to dominate in a broader parameter interval.

  11. Individual wealth-based selection supports cooperation in spatial public goods games

    PubMed Central

    Chen, Xiaojie; Szolnoki, Attila

    2016-01-01

    In a social dilemma game group members are allowed to decide if they contribute to the joint venture or not. As a consequence, defectors, who do not invest but only enjoy the mutual benefit, prevail and the system evolves onto the tragedy of the common state. This unfortunate scenario can be avoided if participation is not obligatory but only happens with a given probability. But what if we also consider a player’s individual wealth when to decide about participation? To address this issue we propose a model in which the probabilistic participation in the public goods game is combined with a conditional investment mode that is based on individual wealth: if a player’s wealth exceeds a threshold value then it is qualified and can participate in the joint venture. Otherwise, the participation is forbidden in the investment interactions. We show that if only probabilistic participation is considered, spatially structured populations cannot support cooperation better than well-mixed populations where full defection state can also be avoided for small participation probabilities. By adding the wealth-based criterion of participation, however, structured populations are capable to augment network reciprocity relevantly and allow cooperator strategy to dominate in a broader parameter interval. PMID:27597441

  12. Robust Feature Selection from Microarray Data Based on Cooperative Game Theory and Qualitative Mutual Information

    PubMed Central

    Mortazavi, Atiyeh; Moattar, Mohammad Hossein

    2016-01-01

    High dimensionality of microarray data sets may lead to low efficiency and overfitting. In this paper, a multiphase cooperative game theoretic feature selection approach is proposed for microarray data classification. In the first phase, due to high dimension of microarray data sets, the features are reduced using one of the two filter-based feature selection methods, namely, mutual information and Fisher ratio. In the second phase, Shapley index is used to evaluate the power of each feature. The main innovation of the proposed approach is to employ Qualitative Mutual Information (QMI) for this purpose. The idea of Qualitative Mutual Information causes the selected features to have more stability and this stability helps to deal with the problem of data imbalance and scarcity. In the third phase, a forward selection scheme is applied which uses a scoring function to weight each feature. The performance of the proposed method is compared with other popular feature selection algorithms such as Fisher ratio, minimum redundancy maximum relevance, and previous works on cooperative game based feature selection. The average classification accuracy on eleven microarray data sets shows that the proposed method improves both average accuracy and average stability compared to other approaches. PMID:27127506

  13. Space Station

    NASA Image and Video Library

    1985-12-01

    Skylab's success proved that scientific experimentation in a low gravity environment was essential to scientific progress. A more permanent structure was needed to provide this space laboratory. President Ronald Reagan, on January 25, 1984, during his State of the Union address, claimed that the United States should exploit the new frontier of space, and directed NASA to build a permanent marned space station within a decade. The idea was that the space station would not only be used as a laboratory for the advancement of science and medicine, but would also provide a staging area for building a lunar base and manned expeditions to Mars and elsewhere in the solar system. President Reagan invited the international community to join with the United States in this endeavour. NASA and several countries moved forward with this concept. By December 1985, the first phase of the space station was well underway with the design concept for the crew compartments and laboratories. Pictured are two NASA astronauts, at Marshall Space Flight Center's (MSFC) Neutral Buoyancy Simulator (NBS), practicing construction techniques they later used to construct the space station after it was deployed.

  14. Estimation of selected streamflow statistics for a network of low-flow partial-record stations in areas affected by Base Realignment and Closure (BRAC) in Maryland

    USGS Publications Warehouse

    Ries, Kernell G.; Eng, Ken

    2010-01-01

    The U.S. Geological Survey, in cooperation with the Maryland Department of the Environment, operated a network of 20 low-flow partial-record stations during 2008 in a region that extends from southwest of Baltimore to the northeastern corner of Maryland to obtain estimates of selected streamflow statistics at the station locations. The study area is expected to face a substantial influx of new residents and businesses as a result of military and civilian personnel transfers associated with the Federal Base Realignment and Closure Act of 2005. The estimated streamflow statistics, which include monthly 85-percent duration flows, the 10-year recurrence-interval minimum base flow, and the 7-day, 10-year low flow, are needed to provide a better understanding of the availability of water resources in the area to be affected by base-realignment activities. Streamflow measurements collected for this study at the low-flow partial-record stations and measurements collected previously for 8 of the 20 stations were related to concurrent daily flows at nearby index streamgages to estimate the streamflow statistics. Three methods were used to estimate the streamflow statistics and two methods were used to select the index streamgages. Of the three methods used to estimate the streamflow statistics, two of them--the Moments and MOVE1 methods--rely on correlating the streamflow measurements at the low-flow partial-record stations with concurrent streamflows at nearby, hydrologically similar index streamgages to determine the estimates. These methods, recommended for use by the U.S. Geological Survey, generally require about 10 streamflow measurements at the low-flow partial-record station. The third method transfers the streamflow statistics from the index streamgage to the partial-record station based on the average of the ratios of the measured streamflows at the partial-record station to the concurrent streamflows at the index streamgage. This method can be used with as few as

  15. Integrating stations from the North America Gravity Database into a local GPS-based land gravity survey

    USGS Publications Warehouse

    Shoberg, Thomas G.; Stoddard, Paul R.

    2013-01-01

    The ability to augment local gravity surveys with additional gravity stations from easily accessible national databases can greatly increase the areal coverage and spatial resolution of a survey. It is, however, necessary to integrate such data seamlessly with the local survey. One challenge to overcome in integrating data from national databases is that these data are typically of unknown quality. This study presents a procedure for the evaluation and seamless integration of gravity data of unknown quality from a national database with data from a local Global Positioning System (GPS)-based survey. The starting components include the latitude, longitude, elevation and observed gravity at each station location. Interpolated surfaces of the complete Bouguer anomaly are used as a means of quality control and comparison. The result is an integrated dataset of varying quality with many stations having GPS accuracy and other reliable stations of unknown origin, yielding a wider coverage and greater spatial resolution than either survey alone.

  16. National surveys of radiofrequency field strengths from radio base stations in Africa

    PubMed Central

    Joyner, Ken H.; Van Wyk, Marthinus J.; Rowley, Jack T.

    2014-01-01

    The authors analysed almost 260 000 measurement points from surveys of radiofrequency (RF) field strengths near radio base stations in seven African countries over two time frames from 2001 to 2003 and 2006 to 2012. The results of the national surveys were compared, chronological trends investigated and potential exposures compared by technology and with frequency modulation (FM) radio. The key findings from thes data are that irrespective of country, the year and mobile technology, RF fields at a ground level were only a small fraction of the international human RF exposure recommendations. Importantly, there has been no significant increase in typical measured levels since the introduction of 3G services. The mean levels in these African countries are similar to the reported levels for countries of Asia, Europe and North America using similar mobile technologies. The median level for the FM services in South Africa was comparable to the individual but generally lower than the combined mobile services. PMID:24044904

  17. National surveys of radiofrequency field strengths from radio base stations in Africa.

    PubMed

    Joyner, Ken H; Van Wyk, Marthinus J; Rowley, Jack T

    2014-01-01

    The authors analysed almost 260 000 measurement points from surveys of radiofrequency (RF) field strengths near radio base stations in seven African countries over two time frames from 2001 to 2003 and 2006 to 2012. The results of the national surveys were compared, chronological trends investigated and potential exposures compared by technology and with frequency modulation (FM) radio. The key findings from thes data are that irrespective of country, the year and mobile technology, RF fields at a ground level were only a small fraction of the international human RF exposure recommendations. Importantly, there has been no significant increase in typical measured levels since the introduction of 3G services. The mean levels in these African countries are similar to the reported levels for countries of Asia, Europe and North America using similar mobile technologies. The median level for the FM services in South Africa was comparable to the individual but generally lower than the combined mobile services.

  18. A Seed-Based Plant Propagation Algorithm: The Feeding Station Model

    PubMed Central

    Salhi, Abdellah

    2015-01-01

    The seasonal production of fruit and seeds is akin to opening a feeding station, such as a restaurant. Agents coming to feed on the fruit are like customers attending the restaurant; they arrive at a certain rate and get served at a certain rate following some appropriate processes. The same applies to birds and animals visiting and feeding on ripe fruit produced by plants such as the strawberry plant. This phenomenon underpins the seed dispersion of the plants. Modelling it as a queuing process results in a seed-based search/optimisation algorithm. This variant of the Plant Propagation Algorithm is described, analysed, tested on nontrivial problems, and compared with well established algorithms. The results are included. PMID:25821858

  19. Life cycle assessment of sewage sludge co-incineration in a coal-based power station.

    PubMed

    Hong, Jingmin; Xu, Changqing; Hong, Jinglan; Tan, Xianfeng; Chen, Wei

    2013-09-01

    A life cycle assessment was conducted to evaluate the environmental and economic effects of sewage sludge co-incineration in a coal-fired power plant. The general approach employed by a coal-fired power plant was also assessed as control. Sewage sludge co-incineration technology causes greater environmental burden than does coal-based energy production technology because of the additional electricity consumption and wastewater treatment required for the pretreatment of sewage sludge, direct emissions from sludge incineration, and incinerated ash disposal processes. However, sewage sludge co-incineration presents higher economic benefits because of electricity subsidies and the income generating potential of sludge. Environmental assessment results indicate that sewage sludge co-incineration is unsuitable for mitigating the increasing pressure brought on by sewage sludge pollution. Reducing the overall environmental effect of sludge co-incineration power stations necessitates increasing net coal consumption efficiency, incinerated ash reuse rate, dedust system efficiency, and sludge water content rate.

  20. Low-cost extrapolation method for maximal LTE radio base station exposure estimation: test and validation.

    PubMed

    Verloock, Leen; Joseph, Wout; Gati, Azeddine; Varsier, Nadège; Flach, Björn; Wiart, Joe; Martens, Luc

    2013-06-01

    An experimental validation of a low-cost method for extrapolation and estimation of the maximal electromagnetic-field exposure from long-term evolution (LTE) radio base station installations are presented. No knowledge on downlink band occupation or service characteristics is required for the low-cost method. The method is applicable in situ. It only requires a basic spectrum analyser with appropriate field probes without the need of expensive dedicated LTE decoders. The method is validated both in laboratory and in situ, for a single-input single-output antenna LTE system and a 2×2 multiple-input multiple-output system, with low deviations in comparison with signals measured using dedicated LTE decoders.

  1. A dynamic case-based planning system for space station application

    NASA Technical Reports Server (NTRS)

    Oppacher, F.; Deugo, D.

    1988-01-01

    We are currently investigating the use of a case-based reasoning approach to develop a dynamic planning system. The dynamic planning system (DPS) is designed to perform resource management, i.e., to efficiently schedule tasks both with and without failed components. This approach deviates from related work on scheduling and on planning in AI in several aspects. In particular, an attempt is made to equip the planner with an ability to cope with a changing environment by dynamic replanning, to handle resource constraints and feedback, and to achieve some robustness and autonomy through plan learning by dynamic memory techniques. We briefly describe the proposed architecture of DPS and its four major components: the PLANNER, the plan EXECUTOR, the dynamic REPLANNER, and the plan EVALUATOR. The planner, which is implemented in Smalltalk, is being evaluated for use in connection with the Space Station Mobile Service System (MSS).

  2. Evaluation of RF electromagnetic field exposure levels from cellular base stations in Korea.

    PubMed

    Kim, Byung Chan; Park, Seong-Ook

    2010-09-01

    This article presents the measurement results of human exposure to CDMA800 and CDMA1800 signals at locations in Korea where the general public has expressed concern. Measurements were performed at 50 locations across the country to compare the electromagnetic field levels with the general public exposure compliance limits. At each site, the distances between the nearest single or co-located base station and measurement positions were within a range of approximately 32-422 m. The measured exposure levels were very low compared with the international standard and the Korean human protection notice. The highest field level was 1.5 V/m, which corresponds to 0.15% of the International Commission on Non-Ionizing Radiation Protection (ICNIRP) guidelines for human exposure. 2010 Wiley-Liss, Inc.

  3. Mobile phone base station radiation does not affect neoplastic transformation in BALB/3T3 cells.

    PubMed

    Hirose, H; Suhara, T; Kaji, N; Sakuma, N; Sekijima, M; Nojima, T; Miyakoshi, J

    2008-01-01

    A large-scale in vitro study focusing on low-level radiofrequency (RF) fields from mobile radio base stations employing the International Mobile Telecommunication 2000 (IMT-2000) cellular system was conducted to test the hypothesis that modulated RF fields affect malignant transformation or other cellular stress responses. Our group previously reported that DNA strand breaks were not induced in human cells exposed to 2.1425 GHz Wideband Code Division Multiple Access (W-CDMA) radiation up to 800 mW/kg from mobile radio base stations employing the IMT-2000 cellular system. In the current study, BALB/3T3 cells were continuously exposed to 2.1425 GHz W-CDMA RF fields at specific absorption rates (SARs) of 80 and 800 mW/kg for 6 weeks and malignant cell transformation was assessed. In addition, 3-methylcholanthrene (MCA)-treated cells were exposed to RF fields in a similar fashion, to assess for effects on tumor promotion. Finally, the effect of RF fields on tumor co-promotion was assessed in BALB/3T3 cells initiated with MCA and co-exposed to 12-O-tetradecanoylphorbol-13-acetate (TPA). At the end of the incubation period, transformation dishes were fixed, stained with Giemsa, and scored for morphologically transformed foci. No significant differences in transformation frequency were observed between the test groups exposed to RF signals and the sham-exposed negative controls in the non-, MCA-, or MCA plus TPA-treated cells. Our studies found no evidence to support the hypothesis that RF fields may affect malignant transformation. Our results suggest that exposure to low-level RF radiation of up to 800 mW/kg does not induce cell transformation, which causes tumor formation. (c) 2007 Wiley-Liss, Inc.

  4. Risk and benefit perceptions of mobile phone and base station technology in Bangladesh.

    PubMed

    van Kleef, Ellen; Fischer, Arnout R H; Khan, Moin; Frewer, Lynn J

    2010-06-01

    Research in developed countries showed that many citizens perceive that radio signals transmitted by mobile phones and base stations represent potential health risks. Less research has been conducted in developing countries focused on citizen perceptions of risks and benefits, despite the recent and rapid introduction of mobile communication technologies. This study aims to identify factors that are influential in determining the tradeoffs that Bangladeshi citizens make between risks and benefits in terms of mobile phone technology acceptance and health concerns associated with the technology. Bangladesh was selected as representative of many developing countries inasmuch as terrestrial telephone infrastructure is insubstantial, and mobile phone use has expanded rapidly over the last decade, even among the poor. Issues of importance were identified in a small-scale qualitative study among Bangladeshi citizens (n = 13), followed by a survey within a sample of Bangladeshi citizens (n = 500). The results demonstrate that, in general, the perceived benefits of mobile phone technology outweigh the risks. The perceived benefits are primarily related to the social and personal advantages of mobile phone use, including the ability to receive emergency news about floods, cyclones, and other natural disasters. Base stations were seen as a symbol of societal advance. The results furthermore suggest that overall risk perceptions are relatively low, in particular health risks, and are primarily driven by perceptions that related to crime and social inconvenience. Perceived health risks are relatively small. These findings show that risk communication and management may be particularly effective when contextual factors of the society where the system is implemented are taken into consideration.

  5. A Lightweight Neighbor-Info-Based Routing Protocol for No-Base-Station Taxi-Call System

    PubMed Central

    Zhu, Xudong; Wang, Jinhang; Chen, Yunchao

    2014-01-01

    Since the quick topology change and short connection duration, the VANET has had unstable routing and wireless signal quality. This paper proposes a kind of lightweight routing protocol-LNIB for call system without base station, which is applicable to the urban taxis. LNIB maintains and predicts neighbor information dynamically, thus finding the reliable path between the source and the target. This paper describes the protocol in detail and evaluates the performance of this protocol by simulating under different nodes density and speed. The result of evaluation shows that the performance of LNIB is better than AODV which is a classic protocol in taxi-call scene. PMID:24737984

  6. A lightweight neighbor-info-based routing protocol for no-base-station taxi-call system.

    PubMed

    Zhu, Xudong; Wang, Jinhang; Chen, Yunchao

    2014-01-01

    Since the quick topology change and short connection duration, the VANET has had unstable routing and wireless signal quality. This paper proposes a kind of lightweight routing protocol-LNIB for call system without base station, which is applicable to the urban taxis. LNIB maintains and predicts neighbor information dynamically, thus finding the reliable path between the source and the target. This paper describes the protocol in detail and evaluates the performance of this protocol by simulating under different nodes density and speed. The result of evaluation shows that the performance of LNIB is better than AODV which is a classic protocol in taxi-call scene.

  7. Classification of e-government documents based on cooperative expression of word vectors

    NASA Astrophysics Data System (ADS)

    Fu, Qianqian; Liu, Hao; Wei, Zhiqiang

    2017-03-01

    The effective document classification is a powerful technique to deal with the huge amount of e-government documents automatically instead of accomplishing them manually. The word-to-vector (word2vec) model, which converts semantic word into low-dimensional vectors, could be successfully employed to classify the e-government documents. In this paper, we propose the cooperative expressions of word vector (Co-word-vector), whose multi-granularity of integration explores the possibility of modeling documents in the semantic space. Meanwhile, we also aim to improve the weighted continuous bag of words model based on word2vec model and distributed representation of topic-words based on LDA model. Furthermore, combining the two levels of word representation, performance result shows that our proposed method on the e-government document classification outperform than the traditional method.

  8. Cooperative Learning through Team-Based Projects in the Biotechnology Industry.

    PubMed

    Luginbuhl, Sarah C; Hamilton, Paul T

    2013-01-01

    We have developed a cooperative-learning, case studies project model that has teams of students working with biotechnology professionals on company-specific problems. These semester-long, team-based projects can be used effectively to provide students with valuable skills in an industry environment and experience addressing real issues faced by biotechnology companies. Using peer-evaluations, we have seen improvement in students' professional skills such as time-management, quality of work, and level of contribution over multiple semesters. This model of team-based, industry-sponsored projects could be implemented in other college and university courses/programs to promote professional skills and expose students to an industry setting.

  9. Cooperative Learning through Team-Based Projects in the Biotechnology Industry †

    PubMed Central

    Luginbuhl, Sarah C.; Hamilton, Paul T.

    2013-01-01

    We have developed a cooperative-learning, case studies project model that has teams of students working with biotechnology professionals on company-specific problems. These semester-long, team-based projects can be used effectively to provide students with valuable skills in an industry environment and experience addressing real issues faced by biotechnology companies. Using peer-evaluations, we have seen improvement in students’ professional skills such as time-management, quality of work, and level of contribution over multiple semesters. This model of team-based, industry-sponsored projects could be implemented in other college and university courses/programs to promote professional skills and expose students to an industry setting. PMID:24358386

  10. Adjusted peak-flow frequency estimates for selected streamflow-gaging stations in or near Montana based on data through water year 2011: Chapter D in Montana StreamStats

    USGS Publications Warehouse

    Sando, Steven K.; Sando, Roy; McCarthy, Peter M.; Dutton, DeAnn M.

    2016-04-05

    Notice:Table 1–2 in this report is being revised. The regression equations for the Northwest Region are being recalculated; the revised report will be posted at this page as soon as it is complete.AbstractThe climatic conditions of the specific time period during which peak-flow data were collected at a given streamflow-gaging station (hereinafter referred to as gaging station) can substantially affect how well the peak-flow frequency (hereinafter referred to as frequency) results represent long-term hydrologic conditions. Differences in the timing of the periods of record can result in substantial inconsistencies in frequency estimates for hydrologically similar gaging stations. Potential for inconsistency increases with decreasing peak-flow record length. The representativeness of the frequency estimates for a short-term gaging station can be adjusted by various methods including weighting the at-site results in association with frequency estimates from regional regression equations (RREs) by using the Weighted Independent Estimates (WIE) program. Also, for gaging stations that cannot be adjusted by using the WIE program because of regulation or drainage areas too large for application of RREs, frequency estimates might be improved by using record extension procedures, including a mixed-station analysis using the maintenance of variance type I (MOVE.1) procedure. The U.S. Geological Survey, in cooperation with the Montana Department of Transportation and the Montana Department of Natural Resources and Conservation, completed a study to provide adjusted frequency estimates for selected gaging stations through water year 2011.The purpose of Chapter D of this Scientific Investigations Report is to present adjusted frequency estimates for 504 selected streamflow-gaging stations in or near Montana based on data through water year 2011. Estimates of peak-flow magnitudes for the 66.7-, 50-, 42.9-, 20-, 10-, 4-, 2-, 1-, 0.5-, and 0.2-percent annual exceedance

  11. Adjusted peak-flow frequency estimates for selected streamflow-gaging stations in or near Montana based on data through water year 2011: Chapter D in Montana StreamStats

    USGS Publications Warehouse

    Sando, Steven K.; Sando, Roy; McCarthy, Peter M.; Dutton, DeAnn M.

    2016-04-05

    The climatic conditions of the specific time period during which peak-flow data were collected at a given streamflow-gaging station (hereinafter referred to as gaging station) can substantially affect how well the peak-flow frequency (hereinafter referred to as frequency) results represent long-term hydrologic conditions. Differences in the timing of the periods of record can result in substantial inconsistencies in frequency estimates for hydrologically similar gaging stations. Potential for inconsistency increases with decreasing peak-flow record length. The representativeness of the frequency estimates for a short-term gaging station can be adjusted by various methods including weighting the at-site results in association with frequency estimates from regional regression equations (RREs) by using the Weighted Independent Estimates (WIE) program. Also, for gaging stations that cannot be adjusted by using the WIE program because of regulation or drainage areas too large for application of RREs, frequency estimates might be improved by using record extension procedures, including a mixed-station analysis using the maintenance of variance type I (MOVE.1) procedure. The U.S. Geological Survey, in cooperation with the Montana Department of Transportation and the Montana Department of Natural Resources and Conservation, completed a study to provide adjusted frequency estimates for selected gaging stations through water year 2011.The purpose of Chapter D of this Scientific Investigations Report is to present adjusted frequency estimates for 504 selected streamflow-gaging stations in or near Montana based on data through water year 2011. Estimates of peak-flow magnitudes for the 66.7-, 50-, 42.9-, 20-, 10-, 4-, 2-, 1-, 0.5-, and 0.2-percent annual exceedance probabilities are reported. These annual exceedance probabilities correspond to the 1.5-, 2-, 2.33-, 5-, 10-, 25-, 50-, 100-, 200-, and 500-year recurrence intervals, respectively.The at-site frequency estimates were

  12. Space Station

    NASA Image and Video Library

    1991-01-01

    In 1982, the Space Station Task Force was formed, signaling the initiation of the Space Station Freedom Program, and eventually resulting in the Marshall Space Flight Center's responsibilities for Space Station Work Package 1.

  13. Evolution of tag-based cooperation on Erdős-Rényi random graphs

    NASA Astrophysics Data System (ADS)

    Lima, F. W. S.; Hadzibeganovic, Tarik; Stauffer, Dietrich

    2014-12-01

    Here, we study an agent-based model of the evolution of tag-mediated cooperation on Erdős-Rényi random graphs. In our model, agents with heritable phenotypic traits play pairwise Prisoner's Dilemma-like games and follow one of the four possible strategies: Ethnocentric, altruistic, egoistic and cosmopolitan. Ethnocentric and cosmopolitan strategies are conditional, i.e. their selection depends upon the shared phenotypic similarity among interacting agents. The remaining two strategies are always unconditional, meaning that egoists always defect while altruists always cooperate. Our simulations revealed that ethnocentrism can win in both early and later evolutionary stages on directed random graphs when reproduction of artificial agents was asexual; however, under the sexual mode of reproduction on a directed random graph, we found that altruists dominate initially for a rather short period of time, whereas ethnocentrics and egoists suppress other strategists and compete for dominance in the intermediate and later evolutionary stages. Among our results, we also find surprisingly regular oscillations which are not damped in the course of time even after half a million Monte Carlo steps. Unlike most previous studies, our findings highlight conditions under which ethnocentrism is less stable or suppressed by other competing strategies.

  14. Current cross-correlations in double quantum dot based Cooper pair splitters with ferromagnetic leads

    NASA Astrophysics Data System (ADS)

    Wrześniewski, Kacper; Trocha, Piotr; Weymann, Ireneusz

    2017-05-01

    We investigate the current cross-correlations in a double quantum dot based Cooper pair splitter coupled to one superconducting and two ferromagnetic electrodes. The analysis is performed by assuming a weak coupling between the double dot and ferromagnetic leads, while the coupling to the superconductor is arbitrary. Employing the perturbative real-time diagrammatic technique, we study the Andreev transport properties of the device, focusing on the Andreev current cross-correlations, for various parameters of the model, both in the linear and nonlinear response regimes. Depending on parameters and transport regime, we find both positive and negative current cross-correlations. Enhancement of the former type of cross-correlations indicates transport regimes, in which the device works with high Cooper pair splitting efficiency, contrary to the latter type of correlations, which imply negative influence on the splitting. The processes and mechanisms leading to both types of current cross-correlations are thoroughly examined and discussed, giving a detailed insight into the Andreev transport properties of the considered device.

  15. Environment Sensitivity-based Cooperative Co-evolutionary Algorithms for Dynamic Multi-objective Optimization.

    PubMed

    Xu, Biao; Zhang, Yong; Gong, Dunwei; Guo, Yinan; Rong, Miao

    2017-01-16

    Dynamic multi-objective optimization problems (DMOPs) not only involve multiple conflicting objectives, but these objectives may also vary with time, raising a challenge for researchers to solve them. This paper presents a cooperative co-evolutionary strategy based on environment sensitivities for solving DMOPs. In this strategy, a new method that groups decision variables is first proposed, in which all the decision variables are partitioned into two subcomponents according to their interrelation with environment. Adopting two populations to cooperatively optimize the two subcomponents, two prediction methods, i.e., differential prediction and Cauchy mutation, are then employed respectively to speed up their responses on the change of the environment. Furthermore, two improved dynamic multi-objective optimization algorithms, i.e., DNSGAII-CO and DMOPSO-CO, are proposed by incorporating the above strategy into NSGA-II and multi-objective particle swarm optimization, respectively. The proposed algorithms are compared with three state-of-the-art algorithms by applying to seven benchmark DMOPs. Experimental results reveal that the proposed algorithms significantly outperform the compared algorithms in terms of convergence and distribution on most DMOPs.

  16. Current cross-correlations in double quantum dot based Cooper pair splitters with ferromagnetic leads.

    PubMed

    Wrześniewski, Kacper; Trocha, Piotr; Weymann, Ireneusz

    2017-05-17

    We investigate the current cross-correlations in a double quantum dot based Cooper pair splitter coupled to one superconducting and two ferromagnetic electrodes. The analysis is performed by assuming a weak coupling between the double dot and ferromagnetic leads, while the coupling to the superconductor is arbitrary. Employing the perturbative real-time diagrammatic technique, we study the Andreev transport properties of the device, focusing on the Andreev current cross-correlations, for various parameters of the model, both in the linear and nonlinear response regimes. Depending on parameters and transport regime, we find both positive and negative current cross-correlations. Enhancement of the former type of cross-correlations indicates transport regimes, in which the device works with high Cooper pair splitting efficiency, contrary to the latter type of correlations, which imply negative influence on the splitting. The processes and mechanisms leading to both types of current cross-correlations are thoroughly examined and discussed, giving a detailed insight into the Andreev transport properties of the considered device.

  17. Temperament and self-based correlates of cooperative, competitive and individualistic learning preferences.

    PubMed

    Gocłowska, Małgorzata A; Aldhobaiban, Nawal; Elliot, Andrew J; Murayama, Kou; Kobeisy, Ahmed; Abdelaziz, Ashraf

    2015-08-28

    People vary in the extent to which they prefer cooperative, competitive or individualistic achievement tasks. In this research, we conducted two studies designed to investigate correlates and possible roots of these social interdependence orientations, namely approach and avoidance temperament, general self-efficacy, implicit theories of intelligence, and contingencies of self-worth based in others' approval, competition and academic competence. The results indicated that approach temperament, general self-efficacy and incremental theory were positively related, and entity theory was negatively related to cooperative preferences (|r| range from .11 to .41); approach temperament, general self-efficacy, competition contingencies and academic competence contingencies were positively related to competitive preferences (|r| range from .16 to .46); and avoidance temperament, entity theory, competitive contingencies and academic competence contingencies were positively related, and incremental theory was negatively related to individualistic preferences (|r| range from .09 to .15). The findings are discussed with regard to the meaning of each of the three social interdependence orientations, cultural differences among the observed relations and implications for practitioners.

  18. Electrochemical sensor for mercury(II) based on conformational switch mediated by interstrand cooperative coordination.

    PubMed

    Liu, Si-Jia; Nie, Hua-Gui; Jiang, Jian-Hui; Shen, Guo-Li; Yu, Ru-Qin

    2009-07-15

    A novel electrochemical sensor was developed for sensitive and selective detection of mercury(II), based on thymine-Hg2+-thymine (T-Hg2+-T) coordination chemistry. This strategy exploited the cooperativity of proximate poly-T oligonucleotides in coordination with Hg2+. Ferrocene (Fc)-tagged poly-T oligonucleotides were immobilized on the electrode surface via self-assembly of the terminal thiol moiety. In the presence of Hg2+, a pair of poly-T oligonucleotides could cooperatively coordinate with Hg2+, which triggered a conformational reorganization of the poly-T oligonucleotides from flexible single strands to relatively rigid duplexlike complexes, thus drawing the Fc tags away from the electrode with a substantially decreased redox current. The response characteristics of the sensor were thoroughly investigated using capillary electrophoresis and electrochemical measurements. The results revealed that the sensor showed a sensitive response to Hg2+ in a concentration range from 1.0 nM to 2.0 microM, with a detection limit of 0.5 nM. Also, this strategy afforded exquisite selectivity for Hg2+ against a reservoir of other environmentally related metal ions, compared to existing anodic stripping voltammetry (ASV) techniques. In addition, this sensor could be implemented using minimal reagents and working steps with excellent reusability through mild regeneration procedure. It was expected that this cost-effective electrochemical sensor might hold considerable potential in on-site applications of Hg2+ detection.

  19. Stereo-vision-based cooperative-vehicle positioning using OCC and neural networks

    NASA Astrophysics Data System (ADS)

    Ifthekhar, Md. Shareef; Saha, Nirzhar; Jang, Yeong Min

    2015-10-01

    Vehicle positioning has been subjected to extensive research regarding driving safety measures and assistance as well as autonomous navigation. The most common positioning technique used in automotive positioning is the global positioning system (GPS). However, GPS is not reliably accurate because of signal blockage caused by high-rise buildings. In addition, GPS is error prone when a vehicle is inside a tunnel. Moreover, GPS and other radio-frequency-based approaches cannot provide orientation information or the position of neighboring vehicles. In this study, we propose a cooperative-vehicle positioning (CVP) technique by using the newly developed optical camera communications (OCC). The OCC technique utilizes image sensors and cameras to receive and decode light-modulated information from light-emitting diodes (LEDs). A vehicle equipped with an OCC transceiver can receive positioning and other information such as speed, lane change, driver's condition, etc., through optical wireless links of neighboring vehicles. Thus, the target vehicle position that is too far away to establish an OCC link can be determined by a computer-vision-based technique combined with the cooperation of neighboring vehicles. In addition, we have devised a back-propagation (BP) neural-network learning method for positioning and range estimation for CVP. The proposed neural-network-based technique can estimate target vehicle position from only two image points of target vehicles using stereo vision. For this, we use rear LEDs on target vehicles as image points. We show from simulation results that our neural-network-based method achieves better accuracy than that of the computer-vision method.

  20. 47 CFR 0.434 - Data bases and lists of authorized broadcast stations and pending broadcast applications.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Data bases and lists of authorized broadcast stations and pending broadcast applications. 0.434 Section 0.434 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL COMMISSION ORGANIZATION General Information Lists Containing Information Compiled by the Commission § 0.434 Data bases...

  1. 33 CFR 334.746 - U.S. Coast Guard, Destin Station at Eglin Air Force Base, Fla.; restricted area.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... at Eglin Air Force Base, Fla.; restricted area. 334.746 Section 334.746 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE DANGER ZONE AND RESTRICTED AREA REGULATIONS § 334.746 U.S. Coast Guard, Destin Station at Eglin Air Force Base, Fla.; restricted area. (a) The...

  2. Performance of a radio link between a base station and a medical implant utilising the MICS standard.

    PubMed

    Johansson, Anders J

    2004-01-01

    Modern medical implants are of increasing complexity and with that, the need for fast and flexible communication with them grows. A wireless system is preferable and an inductive link is the most commonly used. But it has the drawback of a very short range, essentially limited to having the external transceiver touching the patient. The Medical Implant Communication System, MICS, is a standard aimed at improving the communication distance. It operates at a higher frequency band between 402 MHz and 405 MHz. We have by simulations and measurements investigated the channel properties of this band and calculated the link performance for a typical implant application. The result is a link speed between a base station and a bedridden patient of 600 kbit bits per second with a bit error rate of 2% in the downlink to the implant and 1 % in the uplink to the base station. Conclusions on the necessary complexity of the base station are also given.

  3. Ground-based aerosol measurements during CHARMEX/ADRIMED campaign at Granada station

    NASA Astrophysics Data System (ADS)

    Granados-Muñoz, Maria Jose; Bravo-Aranda, Juan Antonio; Navas-Guzman, Francisco; Guerro-Rascado, Juan Luis; Titos, Gloria; Lyamani, Hassan; Valenzuela, Antonio; Cazorla, Alberto; Olmo, Francisco Jose; Mallet, Marc; Alados-Arboledas, Lucas

    2015-04-01

    In the framework of ChArMEx/ADRIMED (Chemistry-Aerosol Mediterranean Experiment, http://charmex.lsce.ipsl.fr/; Aerosol Direct Radiative Impact on the regional climate in the MEDiterranean region) projects, a field experiment based on in situ and remote sensing measurements from surface and airborne platforms was performed. The ADRIMED project aimed to capture the high complexity of the Mediterranean region by using an integrated approach based on intensive experimental field campaign and spaceborne observations, radiative transfer calculations and climate modelling with Regional Climate Models better adapted than global circulation models. For this purpose, measurements were performed at different surface super-sites (including Granada station) over the Occidental Mediterranean region during summer 2013 for creating an updated database of the physical, chemical, optical properties and the vertical distribution of the major "Mediterranean aerosols". Namely, measurements at Granada station were performed on 16 and 17 July 2013, in coincidence with the overpasses of the ATR aircraft over the station. The instrumentation used for the campaign includes both remote sensing instruments (a multiwavelength Raman lidar and a sun photometer) and in-situ measurements (a nephelometer, a Multi-Angle Absorption Photometer (MAAP), an Aerodynamic particle sizer (APS), a high volume sampler of PM10 and an aethalometer). During the measurement period a mineral dust event was detected, with similar dust load on both days. According to in-situ measurements, the event reached the surface level on 16 of June. Vertically resolved lidar measurements indicated presence of mineral dust layers up to 5 km asl both on 16 and 17 June 2013. Temporal evolution analysis indicated that on 17 June the dust layer decoupled from the boundary layer and disappeared around 14:00 UTC. In addition, lidar and sun-photometer data were used to retrieve volume concentration profiles by means of LIRIC (Lidar

  4. Spin exchange optical pumping based polarized {sup 3}He filling station for the Hybrid Spectrometer at the Spallation Neutron Source

    SciTech Connect

    Jiang, C. Y.; Tong, X.; Brown, D. R.; Culbertson, H.; Kadron, B.; Robertson, J. L.; Graves-Brook, M. K.; Hagen, M. E.; Lee, W. T.; Winn, B.

    2013-06-15

    The Hybrid Spectrometer (HYSPEC) is a new direct geometry spectrometer at the Spallation Neutron Source at the Oak Ridge National Laboratory. This instrument is equipped with polarization analysis capability with 60 Degree-Sign horizontal and 15 Degree-Sign vertical detector coverages. In order to provide wide angle polarization analysis for this instrument, we have designed and built a novel polarized {sup 3}He filling station based on the spin exchange optical pumping method. It is designed to supply polarized {sup 3}He gas to HYSPEC as a neutron polarization analyzer. In addition, the station can optimize the {sup 3}He pressure with respect to the scattered neutron energies. The depolarized {sup 3}He gas in the analyzer can be transferred back to the station to be repolarized. We have constructed the prototype filling station. Preliminary tests have been carried out demonstrating the feasibility of the filling station. Here, we report on the design, construction, and the preliminary results of the prototype filling station.

  5. Two-agent cooperative search using game models with endurance-time constraints

    NASA Astrophysics Data System (ADS)

    Sujit, P. B.; Ghose, Debasish

    2010-07-01

    In this article, the problem of two Unmanned Aerial Vehicles (UAVs) cooperatively searching an unknown region is addressed. The search region is discretized into hexagonal cells and each cell is assumed to possess an uncertainty value. The UAVs have to cooperatively search these cells taking limited endurance, sensor and communication range constraints into account. Due to limited endurance, the UAVs need to return to the base station for refuelling and also need to select a base station when multiple base stations are present. This article proposes a route planning algorithm that takes endurance time constraints into account and uses game theoretical strategies to reduce the uncertainty. The route planning algorithm selects only those cells that ensure the agent will return to any one of the available bases. A set of paths are formed using these cells which the game theoretical strategies use to select a path that yields maximum uncertainty reduction. We explore non-cooperative Nash, cooperative and security strategies from game theory to enhance the search effectiveness. Monte-Carlo simulations are carried out which show the superiority of the game theoretical strategies over greedy strategy for different look ahead step length paths. Within the game theoretical strategies, non-cooperative Nash and cooperative strategy perform similarly in an ideal case, but Nash strategy performs better than the cooperative strategy when the perceived information is different. We also propose a heuristic based on partitioning of the search space into sectors to reduce computational overhead without performance degradation.

  6. Mobile phone base stations and adverse health effects: phase 1 of a population-based, cross-sectional study in Germany.

    PubMed

    Blettner, M; Schlehofer, B; Breckenkamp, J; Kowall, B; Schmiedel, S; Reis, U; Potthoff, P; Schüz, J; Berg-Beckhoff, G

    2009-02-01

    The aim of this first phase of a cross-sectional study from Germany was to investigate whether proximity of residence to mobile phone base stations as well as risk perception is associated with health complaints. The researchers conducted a population-based, multi-phase, cross-sectional study within the context of a large panel survey regularly carried out by a private research institute in Germany. In the initial phase, reported on in this paper, 30,047 persons from a total of 51,444 who took part in the nationwide survey also answered questions on how mobile phone base stations affected their health. A list of 38 health complaints was used. A multiple linear regression model was used to identify predictors of health complaints including proximity of residence to mobile phone base stations and risk perception. Of the 30,047 participants (response rate 58.6%), 18.7% of participants were concerned about adverse health effects of mobile phone base stations, while an additional 10.3% attributed their personal adverse health effects to the exposure from them. Participants who were concerned about or attributed adverse health effects to mobile phone base stations and those living in the vicinity of a mobile phone base station (500 m) reported slightly more health complaints than others. A substantial proportion of the German population is concerned about adverse health effects caused by exposure from mobile phone base stations. The observed slightly higher prevalence of health complaints near base stations can not however be fully explained by attributions or concerns.

  7. Free-free and fixed base modal survey tests of the Space Station Common Module Prototype

    NASA Technical Reports Server (NTRS)

    Driskill, T. C.; Anderson, J. B.; Coleman, A. D.

    1992-01-01

    This paper describes the testing aspects and the problems encountered during the free-free and fixed base modal surveys completed on the original Space Station Common Module Prototype (CMP). The CMP is a 40-ft long by 14.5-ft diameter 'waffle-grid' cylinder built by the Boeing Company and housed at the Marshall Space Flight Center (MSFC) near Huntsville, AL. The CMP modal survey tests were conducted at MSFC by the Dynamics Test Branch. The free-free modal survey tests (June '90 to Sept. '90) included interface verification tests (IFVT), often referred to as impedance measurements, mass-additive testing and linearity studies. The fixed base modal survey tests (Feb. '91 to April '91), including linearity studies, were conducted in a fixture designed to constrain the CMP in 7 total degrees-of-freedom at five trunnion interfaces (two primary, two secondary, and the keel). The fixture also incorporated an airbag off-load system designed to alleviate the non-linear effects of friction in the primary and secondary trunnion interfaces. Numerous test configurations were performed with the objective of providing a modal data base for evaluating the various testing methodologies to verify dynamic finite element models used for input to coupled load analysis.

  8. Fiber-distributed Ultra-wideband noise radar with steerable power spectrum and colorless base station.

    PubMed

    Zheng, Jianyu; Wang, Hui; Fu, Jianbin; Wei, Li; Pan, Shilong; Wang, Lixian; Liu, Jianguo; Zhu, Ninghua

    2014-03-10

    A fiber-distributed Ultra-wideband (UWB) noise radar was achieved, which consists of a chaotic UWB noise source based on optoelectronic oscillator (OEO), a fiber-distributed transmission link, a colorless base station (BS), and a cross-correlation processing module. Due to a polarization modulation based microwave photonic filter and an electrical UWB pass-band filter embedded in the feedback loop of the OEO, the power spectrum of chaotic UWB signal could be shaped and notch-filtered to avoid the spectrum-overlay-induced interference to the narrow band signals. Meanwhile, the wavelength-reusing could be implemented in the BS by means of the distributed polarization modulation-to-intensity modulation conversion. The experimental comparison for range finding was carried out as the chaotic UWB signal was notch-filtered at 5.2 GHz and 7.8 GHz or not. Measured results indicate that space resolution with cm-level could be realized after 3-km fiber transmission thanks to the excellent self-correlation property of the UWB noise signal provided by the OEO. The performance deterioration of the radar raised by the energy loss of the notch-filtered noise signal was negligible.

  9. Knowledge-based system V and V in the Space Station Freedom program

    NASA Technical Reports Server (NTRS)

    Kelley, Keith; Hamilton, David; Culbert, Chris

    1992-01-01

    Knowledge Based Systems (KBS's) are expected to be heavily used in the Space Station Freedom Program (SSFP). Although SSFP Verification and Validation (V&V) requirements are based on the latest state-of-the-practice in software engineering technology, they may be insufficient for Knowledge Based Systems (KBS's); it is widely stated that there are differences in both approach and execution between KBS V&V and conventional software V&V. In order to better understand this issue, we have surveyed and/or interviewed developers from sixty expert system projects in order to understand the differences and difficulties in KBS V&V. We have used this survey results to analyze the SSFP V&V requirements for conventional software in order to determine which specific requirements are inappropriate for KBS V&V and why they are inappropriate. Further work will result in a set of recommendations that can be used either as guidelines for applying conventional software V&V requirements to KBS's or as modifications to extend the existing SSFP conventional software V&V requirements to include KBS requirements. The results of this work are significant to many projects, in addition to SSFP, which will involve KBS's.

  10. Comparison of two human-machine-interfaces for cooperative maneuver-based driving.

    PubMed

    Franz, Benjamin; Kauer, Michaela; Blanke, Anton; Schreiber, Michael; Bruder, Ralph; Geyer, Sebastian

    2012-01-01

    In the project "Conduct-by-Wire" which is founded by the German Research Foundation (DFG) cooperative maneuver based driving is examined. In this paper two different input devices (gesture recognition and tactile touch display) are compared in a simulator study with 29 participants. It shows that the major advantage of the gesture recognition is that there is no need for the driver to take his gaze off the road. In contrast, the number of gazes at the tactile touch display is significantly higher. The major advantage of the tactile touch display is that no input errors occurred during the test drives. Conversely, the gesture recognition was significantly worse. Nevertheless, further work is needed to decide which input device is the best.

  11. Assessing the value of cooperation and information exchange in large water resources systems by agent-based optimization

    NASA Astrophysics Data System (ADS)

    Giuliani, M.; Castelletti, A.

    2013-07-01

    Many large-scale water resources systems, especially in transboundary contexts, are characterized by the presence of several and conflicting interests and managed by multiple, institutionally independent decision makers. These systems are often studied adopting a centralized approach based on the assumption of full cooperation and information exchange among the involved parties. Such a perspective is conceptually interesting to quantify the best achievable performance but might have little practical impact given the real political and institutional setting. In this work, we propose a novel decision-analytic framework based on multiagent systems to model and analyze different levels of cooperation and information exchange among multiple decision makers. The Zambezi River basin is used as a case study. According to the proposed agent-based optimization approach, each agent represents a decision maker, whose decisions are defined by an explicit optimization problem considering only the agent's local interests. The economic value of information exchange is estimated comparing a noncooperative setting, where agents act independently, with the first basic level of cooperation, i.e., coordination, characterized by full information exchange. The economic value of cooperation is also estimated by comparison with the ideal, fully cooperative management of the system. Results show that coordination, obtained with complete information exchange, allows the downstream agents to better adapt to the upstream behaviors. The impact of information exchange depends on the objective considered, and we show coordination to be particularly beneficial to environmental interests.

  12. Long-lead station-scale prediction of hydrological droughts in South Korea based on bivariate pattern-based downscaling

    NASA Astrophysics Data System (ADS)

    Sohn, Soo-Jin; Tam, Chi-Yung

    2016-05-01

    Capturing climatic variations in boreal winter to spring (December-May) is essential for properly predicting droughts in South Korea. This study investigates the variability and predictability of the South Korean climate during this extended season, based on observations from 60 station locations and multi-model ensemble (MME) hindcast experiments (1983/1984-2005/2006) archived at the APEC Climate Center (APCC). Multivariate empirical orthogonal function (EOF) analysis results based on observations show that the first two leading modes of winter-to-spring precipitation and temperature variability, which together account for ~80 % of the total variance, are characterized by regional-scale anomalies covering the whole South Korean territory. These modes were also closely related to some of the recurrent large-scale circulation changes in the northern hemisphere during the same season. Consistent with the above, examination of the standardized precipitation evapotranspiration index (SPEI) indicates that drought conditions in South Korea tend to be accompanied by regional-to-continental-scale circulation anomalies over East Asia to the western north Pacific. Motivated by the aforementioned findings on the spatial-temporal coherence among station-scale precipitation and temperature anomalies, a new bivariate and pattern-based downscaling method was developed. The novelty of this method is that precipitation and temperature data were first filtered using multivariate EOFs to enhance their spatial-temporal coherence, before being linked to large-scale circulation variables using canonical correlation analysis (CCA). To test its applicability and to investigate its related potential predictability, a perfect empirical model was first constructed with observed datasets as predictors. Next, a model output statistics (MOS)-type hybrid dynamical-statistical model was developed, using products from nine one-tier climate models as inputs. It was found that, with model sea

  13. Endovascular navigation based on real/virtual environments cooperation for computer-assisted TEAM procedures

    NASA Astrophysics Data System (ADS)

    Goksu, Cemil; Haigron, Pascal; Acosta, Oscar; Lucas, Antoine

    2004-05-01

    Transfemoral Endovascular Aneurysm Management, the less invasive treatment of Aortic Abdominal Aneurysms (AAA), is a highly specialized procedure, using advanced devices and requiring a high degree of clinical expertise. There is a great need for a navigation guidance system able to make this procedure safer and more precise. In this context of computer-assisted minimally invasive interventional procedures, we propose a new framework based on the cooperation between the real environment where the intervention takes place and a patient-specific virtual environment, which contains a virtual operating room including a C-arm model as well as the 3D preoperative patient data. This approach aims to deal with the problem of lack of knowledge about soft tissue behavior by better exploiting available information before and during the intervention through a cooperative approach. In order to assist the TEAM procedure in standard interventional conditions, we applied this framework to design a 3D navigation guidance system, which has been successfully used during three TEAM interventions in the operating room. Intra-operatively, anatomical feature-based 2D/3D registration between a single 2D fluoroscopic view, reproduced from the pose planned in the virtual environment, and the preoperative CT volume, is performed by means of a chamfer distance map. The 3D localization of the endovascular devices (sheath, guide wire, prosthesis) tracked either interactively or automatically on 2D sequences, is constrained to either the 3D vascular tree or a 3D device model. Moreover, we propose a first solution to take into account the tissue deformations during this particular intervention and to update the virtual environment with the intraoperative data.

  14. Behavior-based cooperative robotics applied to multi-target observation

    SciTech Connect

    Parker, L.E.

    1996-12-31

    An important issue that arises in the automation of many security, surveillance, and reconnaissance tasks is that of monitoring (or observing) the movements of targets navigating in a bounded area of interest. A key research issue in these problems is that of sensor placement - determining where sensors should be located to maintain the targets in view. In complex applications involving limited-range sensors, the use of multiple sensors dynamically moving over time is required. In this paper, the author investigates the use of a cooperative team of autonomous sensor-based robots for the observation of multiple moving targets. The author focuses primarily on developing the distributed control strategies that allow the robot team to attempt to minimize the total time in which targets escape observation by some robot team member in the area of interest. The initial efforts on this problem address the aspects of distributed control in homogeneous robot teams with equivalent sensing and movement capabilities working in an uncluttered, bounded area. This paper first formalizes the problem, discusses related work, and then shows that this problem is NP-hard. The author then presents a distributed approximate approach to solving this problem that combines low-level multi-robot control with higher-level control. The low-level control is described in terms of force fields emanating from the targets and the robots. The higher level control is presented in the ALLIANCE formalism, which provides mechanisms for fault tolerant cooperative control, and allows robot team members to adjust their low-level actions based upon the actions of their teammates. The author then presents the results of the ongoing implementation of this approach, both in simulation and on physical robots. To the authors knowledge, this is the first paper addressing this research problem that has been implemented on physical robot teams.

  15. Symposium on roles of and cooperation between academic- and practice-based pharmacy clinicians.

    PubMed

    Birtcher, Kimberly K; Corbett, Stephanie Mallow; Pass, Steven E; Coyle, Elizabeth A; Yeh, Rosa F; Tipton, Joyce; Garey, Kevin W

    2010-02-01

    The findings of an academic symposium as they relate to the history and role of the academic pharmacy clinician, the strengths and limitations of the academic pharmacy clinician model, and the framework for future synergistic work relations among clinical pharmacy practitioners are summarized. On April 23, 2008, a symposium was convened to bring key thought leaders together to discuss the relationship of the academic-based pharmacy clinician and the practice-based pharmacy clinician. Participants included clinical faculty and administrators from two colleges of pharmacy, practice-based clinical pharmacists and pharmacy managers from seven health care institutions, and representatives from the American Association of Colleges of Pharmacy, the American College of Clinical Pharmacy, and the American Society of Health-System Pharmacists. Symposium participants discussed the roles and expectations of clinical pharmacists based on primary affiliation within the contemporary practice model for academic- and practice-based pharmacy clinicians and identified sources of conflict for academic- and practice-based pharmacy clinicians. Symposium participants agreed that in order to succeed, the academic-based and the practice-based pharmacy clinicians must function in a true partnership as each individual has strengths, resources, and benefits to bring to the relationship. Furthermore, knowledge, consideration, and an understanding of the potentially different goals and objectives of each institution are critical. A symposium attended by clinical faculty members and administrators from two colleges of pharmacy, practice-based clinical pharmacists and pharmacy managers from seven health care institutions, and representatives from three national pharmacy organizations was conducted to discuss the roles of and cooperation between academic- and practice-based pharmacy clinicians.

  16. The Mechanical Property Data Base from an Air Force/Industry Cooperative Test Program on High Temperature Aluminum Alloys

    DTIC Science & Technology

    1994-02-01

    WL-TR-94-/,J27 AD-A282 911 THE MECHANICAL PROPERTY DATA BASE FROM AN AIR FORCE/INDUSTRY COOPERATIVE TEST PROGRAM ON HIGH TEMPERATURE ALUMINUM ALLOYS...Property Data Baserfrom an Air Force/ PE 62102F Industry Cooperative Test Program on High Temperature PR 2418 Aluminum Allovs- 6. AUTHOR(S) TA 07 Mary Ann...8217 unlimited. 13. ABSTRACT (Maximum 200 wo:ds) A mechanical property data base on high temperature aluminum alloys produced by Allied Signal (8009’ sheet

  17. [Flaw of demand coverage based method for optimal locations of monitoring stations and modification].

    PubMed

    Liu, Shu-Ming; Li, Zhen-Yu; Chen, Jin-Duan; Wang, Qi; Meng, Fan-Lin

    2010-01-01

    The method of locating online sensor on a water distribution system for monitoring water quality was investigated. A flaw of demand coverage method was identified. To overcome this flaw, a demand coverage index based method was proposed in this paper. The demand coverage index method evaluates a node's representativeness by taking both the total amount of demand coverage and its temporal distribution into account. This increases the calculation accuracy and data representativeness. In order to increase the speed of optimization, a genetic algorithm was employed to solve the optimization problem in this work. Two example water distribution systems were employed to evaluate the performances of both methods. It was obtained that more than 85% of node demand can be covered by 7 monitoring stations for the example water distribution system with 95 nodes. Example applications show that results from this method have better representativeness than the one from demand coverage method. An online monitoring network based on optimal locations obtained from demand coverage method can better represent water quality of the distribution systems.

  18. Exposure assessment of mobile phone base station radiation in an outdoor environment using sequential surrogate modeling.

    PubMed

    Aerts, Sam; Deschrijver, Dirk; Joseph, Wout; Verloock, Leen; Goeminne, Francis; Martens, Luc; Dhaene, Tom

    2013-05-01

    Human exposure to background radiofrequency electromagnetic fields (RF-EMF) has been increasing with the introduction of new technologies. There is a definite need for the quantification of RF-EMF exposure but a robust exposure assessment is not yet possible, mainly due to the lack of a fast and efficient measurement procedure. In this article, a new procedure is proposed for accurately mapping the exposure to base station radiation in an outdoor environment based on surrogate modeling and sequential design, an entirely new approach in the domain of dosimetry for human RF exposure. We tested our procedure in an urban area of about 0.04 km(2) for Global System for Mobile Communications (GSM) technology at 900 MHz (GSM900) using a personal exposimeter. Fifty measurement locations were sufficient to obtain a coarse street exposure map, locating regions of high and low exposure; 70 measurement locations were sufficient to characterize the electric field distribution in the area and build an accurate predictive interpolation model. Hence, accurate GSM900 downlink outdoor exposure maps (for use in, e.g., governmental risk communication and epidemiological studies) are developed by combining the proven efficiency of sequential design with the speed of exposimeter measurements and their ease of handling.

  19. High precision mobile location framework and its service based on virtual reference station of GPS

    NASA Astrophysics Data System (ADS)

    Liu, Chun; Sun, Liangyu; Yao, Lianbi

    2008-10-01

    The wireless communication technology and space technology are synchronously developed in recent years, which bring up the development of location based service (LBS). At present, many location technology methods were developed. However, all these methods can only provide a relative poor location precision and depend on high cost. The technology of Virtual Reference Station (VRS) of GPS is then involved in this paper. One of the objective in this paper is aim to give the LBS position structure to improve the mobile location position when a mobile position instrument is connected with VRS network. The cheaper GPS built-in Personal Designer Aid (PDA) is then used to achieve a higher precision by using RTCM data from existing VRS network. In order to obtain a high precision position when using the low-cost GPS receiver as a rover, the infrusture of the mobile differential correction system is then put forward. According to network transportation of RTCM via internet protocol (NTRIP), the message is communicated through wireless network, such as GPRS, CDMA and so on. The rough coordinate information is sent to VRS control center continuously, and then the VRS correction information is replied to rover in the data format of RTCM3.1. So the position will be updated based on mathematic solution after the decoding of RTCM3.1 data. The thought of LBS position can improve the precision, and can speed the LBS.

  20. Peak-flow frequency analyses and results based on data through water year 2011 for selected streamflow-gaging stations in or near Montana: Chapter C in Montana StreamStats

    USGS Publications Warehouse

    Sando, Steven K.; McCarthy, Peter M.; Dutton, DeAnn M.

    2016-04-05

    Chapter C of this Scientific Investigations Report documents results from a study by the U.S. Geological Survey, in cooperation with the Montana Department of Transportation and the Montana Department of Natural Resources, to provide an update of statewide peak-flow frequency analyses and results for Montana. The purpose of this report chapter is to present peak-flow frequency analyses and results for 725 streamflow-gaging stations in or near Montana based on data through water year 2011. The 725 streamflow-gaging stations included in this study represent nearly all streamflowgaging stations in Montana (plus some from adjacent states or Canadian Provinces) that have at least 10 years of peak-flow records through water year 2011. For 29 of the 725 streamflow-gaging stations, peak-flow frequency analyses and results are reported for both unregulated and regulated conditions. Thus, peak-flow frequency analyses and results are reported for a total of 754 analyses. Estimates of peak-flow magnitudes for 66.7-, 50-, 42.9-, 20-, 10-, 4-, 2-, 1-, 0.5-, and 0.2-percent annual exceedance probabilities are reported. These annual exceedance probabilities correspond to 1.5-, 2-, 2.33-, 5-, 10-, 25-, 50-, 100-, 200-, and 500-year recurrence intervals.

  1. Chinese Meridian Project and its international cooperation

    NASA Astrophysics Data System (ADS)

    Yang, Guotao; Wang, Chi; Jiao, Jing; Liu, Zhengkuan

    2016-07-01

    Meridian Space Weather Monitoring Project (Meridian Project) has a Chinese multi-station chain along 120ºE longitude to monitor space environment, starting from Mohe, the most northern station in China, through Beijing, Wuhan and extended to Zhongshan station in the Antarctic. The Meridian Project consists of 15 observational stations, the instruments includes magnetometer, ionosonde, incoherent scattering radar, HF back-scattering radar, VLF receiver, LIDAR, and Fabry-Perot interferometer (FPI). The Meridian Project has finished its construction phase in 2012, and started its running phase in 2013. Until now, more than 100 papers have been published by using Meridian Project data. The Meridian Project also provide service for Chinese space activity. The International Space Weather Meridian Circle Program (IMCP) is based upon the Meridian Project. With the international cooperation around this circle, we should take full advantage of foreign resources. The Meridian Project will be extended to Russian, though many Southeast Asia countries such as Australia, and so on. Furthermore, it will be extended to the countries located in the west hemisphere near 60° meridian. The first and only ground-based global space weather monitoring circle will be formed. Cooperation agreements for IMCP have been signed, and we will develop IMCP more deeply in the 2016 COSPAR meeting.

  2. Antenna modeling considerations for accurate SAR calculations in human phantoms in close proximity to GSM cellular base station antennas.

    PubMed

    van Wyk, Marnus J; Bingle, Marianne; Meyer, Frans J C

    2005-09-01

    International bodies such as International Commission on Non-Ionizing Radiation Protection (ICNIRP) and the Institute for Electrical and Electronic Engineering (IEEE) make provision for human exposure assessment based on SAR calculations (or measurements) and basic restrictions. In the case of base station exposure this is mostly applicable to occupational exposure scenarios in the very near field of these antennas where the conservative reference level criteria could be unnecessarily restrictive. This study presents a variety of critical aspects that need to be considered when calculating SAR in a human body close to a mobile phone base station antenna. A hybrid FEM/MoM technique is proposed as a suitable numerical method to obtain accurate results. The verification of the FEM/MoM implementation has been presented in a previous publication; the focus of this study is an investigation into the detail that must be included in a numerical model of the antenna, to accurately represent the real-world scenario. This is accomplished by comparing numerical results to measurements for a generic GSM base station antenna and appropriate, representative canonical and human phantoms. The results show that it is critical to take the disturbance effect of the human phantom (a large conductive body) on the base station antenna into account when the antenna-phantom spacing is less than 300 mm. For these small spacings, the antenna structure must be modeled in detail. The conclusion is that it is feasible to calculate, using the proposed techniques and methodology, accurate occupational compliance zones around base station antennas based on a SAR profile and basic restriction guidelines.

  3. Analysis on influencing factors of EV charging station planning based on AHP

    NASA Astrophysics Data System (ADS)

    Yan, F.; Ma, X. F.

    2016-08-01

    As a new means of transport, electric vehicle (EV) is of great significance to alleviate the energy crisis. EV charging station planning has a far-reaching significance for the development of EV industry. This paper analyzes the impact factors of EV charging station planning, and then uses the analytic hierarchy process (AHP) to carry on the further analysis to the influencing factors, finally it gets the weight of each influence factor, and provides the basis for the evaluation scheme of the planning of charging stations for EV.

  4. Statistical analysis of electromagnetic radiation measurements in the vicinity of GSM/UMTS base station installed on buildings in Serbia.

    PubMed

    Koprivica, Mladen; Slavkovic, Vladimir; Neskovic, Natasa; Neskovic, Aleksandar

    2016-03-01

    As a result of dense deployment of public mobile base stations, additional electromagnetic (EM) radiation occurs in the modern human environment. At the same time, public concern about the exposure to EM radiation emitted by such sources has increased. In order to determine the level of radio frequency radiation generated by base stations, extensive EM field strength measurements were carried out for 664 base station locations, from which 276 locations refer to the case of base stations with antenna system installed on buildings. Having in mind the large percentage (42 %) of locations with installations on buildings, as well as the inevitable presence of people in their vicinity, a detailed analysis of this location category was performed. Measurement results showed that the maximum recorded value of total electric field strength has exceeded International Commission on Non-Ionizing Radiation Protection general public exposure reference levels at 2.5 % of locations and Serbian national reference levels at 15.6 % of locations. It should be emphasised that the values exceeding the reference levels were observed only outdoor, while in indoor total electric field strength in no case exceeded the defined reference levels. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  5. International Space Station (ISS)

    NASA Image and Video Library

    2007-11-05

    Back dropped by the blackness of space and Earth's horizon is the International Space Station (ISS) as seen from Space Shuttle Discovery as the two spacecraft begin their relative separation. The latest configuration of the ISS includes the Italian-built U.S. Node 2, named Harmony, and the P6 truss segment installed over 11 days of cooperative work onboard the shuttle and station by the STS-120 and Expedition 16 crews. Undocking of the two spacecraft occurred at 4:32 a.m. (CST) on Nov. 5, 2007.

  6. International Space Station (ISS)

    NASA Image and Video Library

    2007-11-05

    Back dropped by the blueness of Earth is the International Space Station (ISS) as seen from Space Shuttle Discovery as the two spacecraft begin their relative separation. The latest configuration of the ISS includes the Italian-built U.S. Node 2, named Harmony, and the P6 truss segment installed over 11 days of cooperative work onboard the shuttle and station by the STS-120 and Expedition 16 crews. Undocking of the two spacecraft occurred at 4:32 a.m. (CST) on Nov. 5, 2007.

  7. Regulation during Cooperative and Collaborative Learning: A Theory-Based Review of Terms and Concepts

    ERIC Educational Resources Information Center

    Schoor, Cornelia; Narciss, Susanne; Körndle, Hermann

    2015-01-01

    This article reviews the terms and concepts that have been used for describing regulation of learning during cooperative and collaborative learning and suggests differentiating them on the basis of which parts of a regulatory feedback loop model are being shared. During cooperative and collaborative learning, not only self-regulation but also the…

  8. Student Teachers' Perceptions of Cooperating Teachers as Teacher Educators: Development of Standards Based Scales

    ERIC Educational Resources Information Center

    Holbert, Romena M. Garrett

    2011-01-01

    Cooperating teachers play important roles in student teachers' development as educators. The purpose of this study was to develop a measure that enables systematic investigation of the actions and interactions of cooperating teachers during student teaching. Three sets of educational standards lent focus to this work. The measures developed were…

  9. Regulation during Cooperative and Collaborative Learning: A Theory-Based Review of Terms and Concepts

    ERIC Educational Resources Information Center

    Schoor, Cornelia; Narciss, Susanne; Körndle, Hermann

    2015-01-01

    This article reviews the terms and concepts that have been used for describing regulation of learning during cooperative and collaborative learning and suggests differentiating them on the basis of which parts of a regulatory feedback loop model are being shared. During cooperative and collaborative learning, not only self-regulation but also the…

  10. Field investigation source area ST58 old Quartermaster service station, Eielson Air Force Base, Alaska

    SciTech Connect

    Liikala, T.L.; Evans, J.C.

    1995-01-01

    Source area ST58 is the site of the old Quartermaster service station at Eielson Air Force Base, Alaska. The source area is one of several Source Evaluation Report sites being investigated by Pacific Northwest Laboratory for the US Air Force as candidates for no further remedial action, interim removal action, or a remedial investigation/feasibility study under a Federal Facilities Agreement. The purpose of this work was to characterize source area ST58 and excavate the most contaminated soils for use in composting treatability studies. A field investigation was conducted to determine the nature and extent of soil contamination. The field investigation entailed a records search; grid node location, surface geophysical, and soil gas surveys; and test pit soil sampling. Soil excavation followed based on the results of the field investigation. The site was backfilled with clean soil. Results from this work indicate close spatial correlation between screening instruments, used during the field investigation and soil excavation, and laboratory analyses. Gasoline was identified as the main subsurface contaminant based on the soil gas surveys and test pit soil sampling. A center of contamination was located near the northcentral portion of the source area, and a center was located in the northwestern comer. The contamination typically occurred near or below a former soil horizon probably as a result of surface spills and leaks from discontinuities and/or breaks in the underground piping. Piping locations were delineated during the surface geophysical surveys and corresponded very well to unscaled drawings of the site. The high subsurface concentrations of gasoline detected in the northwestern comer of the source area probably reflect ground-water contamination and/or possibly floating product.

  11. Cooperative intelligent robotics in space III; Proceedings of the Meeting, Boston, MA, Nov. 16-18, 1992

    NASA Technical Reports Server (NTRS)

    Erickson, Jon D. (Editor)

    1992-01-01

    The present volume on cooperative intelligent robotics in space discusses sensing and perception, Space Station Freedom robotics, cooperative human/intelligent robot teams, and intelligent space robotics. Attention is given to space robotics reasoning and control, ground-based space applications, intelligent space robotics architectures, free-flying orbital space robotics, and cooperative intelligent robotics in space exploration. Topics addressed include proportional proximity sensing for telerobots using coherent lasar radar, ground operation of the mobile servicing system on Space Station Freedom, teleprogramming a cooperative space robotic workcell for space stations, and knowledge-based task planning for the special-purpose dextrous manipulator. Also discussed are dimensions of complexity in learning from interactive instruction, an overview of the dynamic predictive architecture for robotic assistants, recent developments at the Goddard engineering testbed, and parallel fault-tolerant robot control.

  12. Measurement and analysis of radiofrequency radiations from some mobile phone base stations in Ghana.

    PubMed

    Amoako, J K; Fletcher, J J; Darko, E O

    2009-08-01

    A survey of the radiofrequency electromagnetic radiation at public access points in the vicinity of 50 cellular phone base stations has been carried out. The primary objective was to measure and analyse the electromagnetic field strength levels emitted by antennae installed and operated by the Ghana Telecommunications Company. On all the sites measurements were made using a hand-held spectrum analyser to determine the electric field level with the 900 and 1800 MHz frequency bands. The results indicated that power densities at public access points varied from as low as 0.01 microW m(-2) to as high as 10 microW m(-2) for the frequency of 900 MHz. At a transmission frequency of 1800 MHz, the variation of power densities is from 0.01 to 100 microW m(-2). The results were found to be in compliant with the International Commission on Non-ionizing Radiological Protection guidance level but were 20 times higher than the results generally obtained for such a practice elsewhere. There is therefore a need to re-assess the situation to ensure reduction in the present level as an increase in mobile phone usage is envisaged within the next few years.

  13. Animal carcinogenicity studies on radiofrequency fields related to mobile phones and base stations

    SciTech Connect

    Dasenbrock, Clemens . E-mail: clemens-dasebrock@bc.boehringer-ingelheim.com

    2005-09-01

    Since a report in 1997 on an increased lymphoma incidence in mice chronically exposed to a mobile phone radiofrequency signal, none of the subsequent long-term studies in rodents have confirmed these results. On the other hand, several of the follow-up co- and carcinogenicity studies are still underway or are presently being initiated. Most of the published long-term studies used 1 exposure level only and suffer from a poor dosimetry which does not consider the animal's growth. Additional points of criticism are a limited, in some cases, questionable histopathology and inadequate group sizes. Overall, if dealing with new chemicals or drugs, these studies would not be acceptable for registration with the responsible authorities. The major critical points are taken into consideration within the European co- and carcinogenicity projects (CEMFEC and PERFORM-A), which are in their final stages and in the US long-term studies in mice and rats which are about to be initiated. Nevertheless, the WHO evaluation for health risk assessment of long-term telephone use and base station exposure will start in late 2005.

  14. A fault diagnosis system for PV power station based on global partitioned gradually approximation method

    NASA Astrophysics Data System (ADS)

    Wang, S.; Zhang, X. N.; Gao, D. D.; Liu, H. X.; Ye, J.; Li, L. R.

    2016-08-01

    As the solar photovoltaic (PV) power is applied extensively, more attentions are paid to the maintenance and fault diagnosis of PV power plants. Based on analysis of the structure of PV power station, the global partitioned gradually approximation method is proposed as a fault diagnosis algorithm to determine and locate the fault of PV panels. The PV array is divided into 16x16 blocks and numbered. On the basis of modularly processing of the PV array, the current values of each block are analyzed. The mean current value of each block is used for calculating the fault weigh factor. The fault threshold is defined to determine the fault, and the shade is considered to reduce the probability of misjudgments. A fault diagnosis system is designed and implemented with LabVIEW. And it has some functions including the data realtime display, online check, statistics, real-time prediction and fault diagnosis. Through the data from PV plants, the algorithm is verified. The results show that the fault diagnosis results are accurate, and the system works well. The validity and the possibility of the system are verified by the results as well. The developed system will be benefit for the maintenance and management of large scale PV array.

  15. Rainy season change in Sanjiangyuan, China area based on the meteorological stations data

    NASA Astrophysics Data System (ADS)

    Cai, Zhanqing; Peng, Dailiang; Wen, Jingyi; Gong, Zhi; Wang, Tiantian; Hu, Yuekai; Wu, Yuxi; Xu, Junfeng

    2017-07-01

    The Sanjiangyuan area is famous as the Chinese water tower, it is a transition zone of semi-humid, semi-arid and arid area. An area of about 400,000 square kilometers and the water source of billions of people, also the ecological barrier of the whole of Asia’s economic and social development.Based on the daily rainfall data of 13 meteorological stations in Sanjiangyuan area from 1985 to 2015, the rainfall indexes such as the rainy season from the beginning and the ending of the rainy season were extracted. And the trend of rainy season in the study area was analyzed. The results show that the daily rainfall in the Sanjiangyuan area accounts for more than 50% of the annual rainfall; the onset of the rainy season in the eastern part of Sanjiangyuan has a delayed trend and the central area has a tendency to advance; the number of days in the rainy season has decreased in the past 30 years, reduced 4d. There is a positive correlation between the starting date of rainy season and the average rainfall in the rainy season. The changes of these rainy seasons are of great significance to the economic development and ecological protection of the region.

  16. What input data are needed to accurately model electromagnetic fields from mobile phone base stations?

    PubMed

    Beekhuizen, Johan; Kromhout, Hans; Bürgi, Alfred; Huss, Anke; Vermeulen, Roel

    2015-01-01

    The increase in mobile communication technology has led to concern about potential health effects of radio frequency electromagnetic fields (RF-EMFs) from mobile phone base stations. Different RF-EMF prediction models have been applied to assess population exposure to RF-EMF. Our study examines what input data are needed to accurately model RF-EMF, as detailed data are not always available for epidemiological studies. We used NISMap, a 3D radio wave propagation model, to test models with various levels of detail in building and antenna input data. The model outcomes were compared with outdoor measurements taken in Amsterdam, the Netherlands. Results showed good agreement between modelled and measured RF-EMF when 3D building data and basic antenna information (location, height, frequency and direction) were used: Spearman correlations were >0.6. Model performance was not sensitive to changes in building damping parameters. Antenna-specific information about down-tilt, type and output power did not significantly improve model performance compared with using average down-tilt and power values, or assuming one standard antenna type. We conclude that 3D radio wave propagation modelling is a feasible approach to predict outdoor RF-EMF levels for ranking exposure levels in epidemiological studies, when 3D building data and information on the antenna height, frequency, location and direction are available.

  17. Comparative international analysis of radiofrequency exposure surveys of mobile communication radio base stations.

    PubMed

    Rowley, Jack T; Joyner, Ken H

    2012-01-01

    This paper presents analyses of data from surveys of radio base stations in 23 countries across five continents from the year 2000 onward and includes over 173,000 individual data points. The research compared the results of the national surveys, investigated chronological trends and compared exposures by technology. The key findings from this data are that irrespective of country, the year and cellular technology, exposures to radio signals at ground level were only a small fraction of the relevant human exposure standards. Importantly, there has been no significant increase in exposure levels since the widespread introduction of 3G mobile services, which should be reassuring for policy makers and negate the need for post-installation measurements at ground level for compliance purposes. There may be areas close to antennas where compliance levels could be exceeded. Future potential work includes extending the study to additional countries, development of cumulative exposure distributions and investigating the possibility of linking exposure measurements to population statistics to assess the distribution of exposure levels relative to population percentiles.

  18. Soyuz-TM-based interim Assured Crew Return Vehicle (ACRV) for the Space Station Freedom

    NASA Technical Reports Server (NTRS)

    Semenov, Yu. P.; Babkov, Oleg I.; Timchenko, Vladimir A.; Craig, Jerry W.

    1993-01-01

    The concept of using the available Soyuz-TM Assured Crew Return Vehicle (ACRV) spacecraft for the assurance of the safety of the Space Station Freedom (SSF) crew after the departure of the Space Shuttle from SSF was proposed by the NPO Energia and was accepted by NASA in 1992. The ACRV will provide the crew with the capability to evacuate a seriously injured/ill crewmember from the SSF to a ground-based care facility under medically tolerable conditions and with the capability for a safe evacuation from SSF in the events SSF becomes uninhabitable or the Space Shuttle flights are interrupted for a time that exceeds SSF ability for crew support and/or safe operations. This paper presents the main results of studies on Phase A (including studies on the service life of ACRV; spacecraft design and operations; prelaunch processing; mission support; safety, reliability, maintenance and quality and assurance; landing, and search/rescue operations; interfaces with the SSF and with Space Shuttle; crew accommodation; motion of orbital an service modules; and ACRV injection by the Expendable Launch Vehicles), along with the objectives of further work on the Phase B.

  19. Study of variations of radiofrequency power density from mobile phone base stations with distance.

    PubMed

    Ayinmode, B O; Farai, I P

    2013-10-01

    The variations of radiofrequency (RF) radiation power density with distance around some mobile phone base stations (BTSs), in ten randomly selected locations in Ibadan, western Nigeria, were studied. Measurements were made with a calibrated hand-held spectrum analyser. The maximum Global System of Mobile (GSM) communication 1800 signal power density was 323.91 µW m(-2) at 250 m radius of a BTS and that of GSM 900 was 1119.00 µW m(-2) at 200 m radius of another BTS. The estimated total maximum power density was 2972.00 µW m(-2) at 50 m radius of a different BTS. This study shows that the maximum carrier signal power density and the total maximum power density from a BTS may be observed averagely at 200 and 50 m of its radius, respectively. The result of this study demonstrates that exposure of people to RF radiation from phone BTSs in Ibadan city is far less than the recommended limits by International scientific bodies.

  20. Soyuz-TM-based interim Assured Crew Return Vehicle (ACRV) for the Space Station Freedom

    NASA Technical Reports Server (NTRS)

    Semenov, Yu. P.; Babkov, Oleg I.; Timchenko, Vladimir A.; Craig, Jerry W.

    1993-01-01

    The concept of using the available Soyuz-TM Assured Crew Return Vehicle (ACRV) spacecraft for the assurance of the safety of the Space Station Freedom (SSF) crew after the departure of the Space Shuttle from SSF was proposed by the NPO Energia and was accepted by NASA in 1992. The ACRV will provide the crew with the capability to evacuate a seriously injured/ill crewmember from the SSF to a ground-based care facility under medically tolerable conditions and with the capability for a safe evacuation from SSF in the events SSF becomes uninhabitable or the Space Shuttle flights are interrupted for a time that exceeds SSF ability for crew support and/or safe operations. This paper presents the main results of studies on Phase A (including studies on the service life of ACRV; spacecraft design and operations; prelaunch processing; mission support; safety, reliability, maintenance and quality and assurance; landing, and search/rescue operations; interfaces with the SSF and with Space Shuttle; crew accommodation; motion of orbital an service modules; and ACRV injection by the Expendable Launch Vehicles), along with the objectives of further work on the Phase B.

  1. Comparative international analysis of radiofrequency exposure surveys of mobile communication radio base stations

    PubMed Central

    Rowley, Jack T; Joyner, Ken H

    2012-01-01

    This paper presents analyses of data from surveys of radio base stations in 23 countries across five continents from the year 2000 onward and includes over 173,000 individual data points. The research compared the results of the national surveys, investigated chronological trends and compared exposures by technology. The key findings from this data are that irrespective of country, the year and cellular technology, exposures to radio signals at ground level were only a small fraction of the relevant human exposure standards. Importantly, there has been no significant increase in exposure levels since the widespread introduction of 3G mobile services, which should be reassuring for policy makers and negate the need for post-installation measurements at ground level for compliance purposes. There may be areas close to antennas where compliance levels could be exceeded. Future potential work includes extending the study to additional countries, development of cumulative exposure distributions and investigating the possibility of linking exposure measurements to population statistics to assess the distribution of exposure levels relative to population percentiles. PMID:22377680

  2. Antarctic station-based seasonal pressure reconstructions since 1905: 1. Reconstruction evaluation

    NASA Astrophysics Data System (ADS)

    Fogt, Ryan L.; Goergens, Chad A.; Jones, Megan E.; Witte, Grant A.; Lee, Ming Yueng; Jones, Julie M.

    2016-03-01

    Seasonal mean Antarctic pressures at 17 stations are reconstructed based on the method of principal component regression, employing midlatitude pressure data as predictors. Several reconstruction methods were performed in order to assess the stability and reliability of the reconstructions obtained, including performing the reconstructions over a shorter 30 year window and withholding the remaining data for an independent validation. Generally, there were small differences between the various approaches, but typically reconstructions conducted on data with the trends still present and over the full period of observations achieved the highest skill. Seasonally, reconstruction skill was high in austral summer across the entire Antarctic continent. Reconstructions that employed gridded pressure data over oceans as well as the observations (here termed "pseudoreconstructions") also performed remarkably well in austral winter. Spatially, the reconstruction skill was highest near the Antarctic Peninsula in all seasons, and weakest in coastal East Antarctica and the Antarctic Interior during austral spring and autumn; the spatial variability of the skill in part reflects the distance to the nearest midlatitude predictor. Nonetheless, for nearly all seasons and locations the observed trends since 1957 were well captured by the reconstructions, as was the low-frequency decadal-scale variability. These results suggest Antarctic pressure observations can be extended throughout the twentieth century with high confidence, especially in summer, allowing for a more precise understanding of the role and magnitude of natural atmospheric circulation variability across Antarctica.

  3. A web-based tool that combines satellite and weather station observations to support irrigation scheduling

    USDA-ARS?s Scientific Manuscript database

    Abstract: The Satellite Irrigation Management Support (SIMS) project combines NASA's Terrestrial Observation and Prediction System (TOPS), Landsat and MODIS satellite imagery, and reference evapotranspiration from surface weather station networks to map daily crop irrigation demand in California in ...

  4. Characteristics of human arm based on musculoskeletal model in human-human cooperative task

    NASA Astrophysics Data System (ADS)

    Zhang, Nan; Ikeura, Ryojun; Wang, Yuanxin; Mizutani, Kazuki; Sawai, Hideki

    2007-12-01

    Human characteristics are supposed to be applied to the control systems of the human-friendly robots. Therefore, it is important to know the human characteristics in human-robot cooperative tasks. In this study, we considered a single rotational degree of freedom experimental system as well as a mass-spring-damper-friction dynamic model for the human arm and analyzed the master-slave and the master-semi master cooperative motions. Through the master-slave cooperative motion, we verified the application of the mass-spring-friction dynamic model of the slave's arm, and regarding its parameter we found the damping factor as zero and the stiffness as well as the coulomb friction torque almost individually invariable. Through the master-semi master cooperative motion, we got the torque characteristics and drew a comparison of them with those in the master-slave cooperative motion, and then we found improved torque characteristics, the constant torque characteristics.

  5. UV climatology at Palmer Station, Antarctica, based on Version 2 NSF network data

    NASA Astrophysics Data System (ADS)

    Bernhard, Germar; Booth, Charles R.; Ehramjian, James C.

    2005-08-01

    Spectral ultraviolet (UV) and visible irradiance has been measured at Palmer Station, Antarctica, between 1988 and 2004 with a SUV-100 spectroradiometer. The instrument is part of the U.S. National Science Foundation's UV Monitoring Network. Here we present a UV climatology for Palmer Station based on the recently produced "Version 2" data edition. This data set will supersede the original release "Version 0". Corrections applied to the new version increased biologically effective UV dose rates by 0-9%. Values of UV-A irradiance changed by -8% to +10%. A comparison with results of a radiative transfer model confirmed that measurements of different years are consistent to within +/-5%. Total ozone column was calculated from UV spectra and was found to agree with measurements of NASA's Total Ozone Mapping Spectrometer (TOMS) installed on the Nimbus-7 satellite to within 1%. TOMS measurements on the Earth Probe satellite are 3% lower than SUV-100 data. Effective surface albedo was estimated from clear sky spectra. Between August and November, albedo typically ranges between 0.6 and 0.95. After melting of snow and sea ice, albedo varies between 0.3 and 0.5. Biologically effective UV radiation is largest in November and December when low total ozone amounts coincide with relatively small solar zenith angles (SZA). During these months, the noon-time UV Index typically varies between 4 and 7, but UV indices as high as 14.8 have been observed. The largest erythemal daily dose of 8.8 kJ/m2 was measured on 11/10/97 and 12/7/98. Linear regression analyses did not indicate statistically significant trends in UV or visible radiation, with the exception of February when small downward trends with statistical significance were observed. On average, clouds reduce UV irradiance at 345 nm between 28% (October and November) and 42% (February) compared to clear sky levels. In extreme cases, reductions by clouds can be as high as 90%. Between September and November, the variability

  6. 49 CFR 37.57 - Required cooperation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 1 2010-10-01 2010-10-01 false Required cooperation. 37.57 Section 37.57... DISABILITIES (ADA) Transportation Facilities § 37.57 Required cooperation. An owner or person in control of an intercity or commuter rail station shall provide reasonable cooperation to the responsible person(s)...

  7. 49 CFR 37.57 - Required cooperation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 1 2011-10-01 2011-10-01 false Required cooperation. 37.57 Section 37.57... DISABILITIES (ADA) Transportation Facilities § 37.57 Required cooperation. An owner or person in control of an intercity or commuter rail station shall provide reasonable cooperation to the responsible person(s)...

  8. 49 CFR 37.57 - Required cooperation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 1 2014-10-01 2014-10-01 false Required cooperation. 37.57 Section 37.57... DISABILITIES (ADA) Transportation Facilities § 37.57 Required cooperation. An owner or person in control of an intercity or commuter rail station shall provide reasonable cooperation to the responsible person(s)...

  9. 49 CFR 37.57 - Required cooperation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 1 2012-10-01 2012-10-01 false Required cooperation. 37.57 Section 37.57... DISABILITIES (ADA) Transportation Facilities § 37.57 Required cooperation. An owner or person in control of an intercity or commuter rail station shall provide reasonable cooperation to the responsible person(s)...

  10. 49 CFR 37.57 - Required cooperation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 1 2013-10-01 2013-10-01 false Required cooperation. 37.57 Section 37.57... DISABILITIES (ADA) Transportation Facilities § 37.57 Required cooperation. An owner or person in control of an intercity or commuter rail station shall provide reasonable cooperation to the responsible person(s)...

  11. Environmental Assessment for the Construction of a New Fire Station, Edwards Air Force Base, California

    DTIC Science & Technology

    2006-10-01

    and a separate 2,500-square foot storage facility. The cost of the construction project is estimated at $8.4 million. J Under Alternative B, the No...HWSF Hazardous Waste Storage Facility IAP initial accumulation point ICE internal combustion engine IMT information management tool INRMP...would also require a separate storage facility of approximately 2,500 square feet. The new fire station would replace the current Fire Station 1

  12. Crewmember activity in the middeck and Mir Space Station Base Block

    NASA Image and Video Library

    2016-08-24

    STS091-361-034 (2-12 June 1998) --- Andrew S.W. Thomas signs a plaque containing the names of all the visitors to Russia's Mir space station. Thomas is the final of seven NASA astronauts to serve as a guest cosmonaut researcher aboard Mir as part of International Space Station (ISS) Phase I. Looking on in the background are astronauts Franklin R. Chang-Diaz, payload commander; and Janet L. Kavandi, mission specialist.

  13. Micromechanically-based formulation of the cooperative model for the yield behavior of starch-based nano-biocomposites.

    PubMed

    Chivrac, F; Gueguen, O; Pollet, E; Averous, L; Ahzi, S; Belouettar, S

    2010-04-01

    The tensile yield stress of plasticized starch filled with montmorillonite has been studied as a function of the temperature and the strain rate and has been compared to the yield behavior of the original matrix. Aggregated/intercalated and exfoliated nano-biocomposites, obtained from different nanofillers, have been produced and tested under uniaxial tension (tensile test). To model the nanocomposite tensile yield stress behavior, a preexisting micro-mechanically based cooperative model, which describes properly the yield of semi-crystalline polymers has been modified. According to our development, the yield behavior of nano-biocomposites is strongly dependant on the clay concentration and exfoliation ratio. Based on the thermodynamics properties, an effective activation volume and effective activation energy are computed through the Takayanagi homogenization model. The predicted results for the yield stress at low strain rates and at different temperatures are in agreement with our experimental results.

  14. Space Station

    NASA Image and Video Library

    1977-01-01

    The Marshall Space Flight Center (MSFC) and the Johnson Space Center (JSC) were each awarded 16-month contracts in April 1976 for the Space Station Systems Analysis Study (SSSAS). Grumman Aerospace Corporation was MSFC's contractor and McDornell Douglas Aerospace Company was JSC's contractor. The goal of this study was to formulate plans for a permanent operational base and laboratory facility in Earth orbit in addition to developing a space construction base design for implementing the program. An expended Space Shuttle external tank was to be the central core platform of the base, and additional pressurized modules could be added to provide laboratory facilities. This artist's concept depicts a space construction base design for implementing the SSSAS.

  15. A total station spatial positioning method based on rotary laser scanning and ultrasonic ranging

    NASA Astrophysics Data System (ADS)

    Wu, Jun; Zhu, Jigui; Yu, Zhijing; Zhuge, Jingchang; Xue, Bin

    2016-11-01

    Total station spatial coordinator measuring technology is extensively applied in the large-scale measurement of industrial assembly and manufacturing for its flexibility and adaptability. The existing total station technology has some principal limits such as poor efficiency and single tasking; in order to achieve the total station spatial coordinator measuring technology with the advantages of multi-task, real-time measurement, and high accuracy, this paper presents a novel total station measurement method by using multi-laser plane constraints established through rotating planar planes and distance information obtained with an ultrasonic ranging method. With the spatial divergence angles of the optoelectronic scanning and ultrasonic arrays, this method can measure the spatial coordinates in multi-task and real-time with a single station and a portable target bar. Experimental results show that the proposed method is feasible and valid with satisfactory accuracy. The maximum distance measurement error is less than 0.2 mm in a volume that is 5 m far away from the station.

  16. A total station spatial positioning method based on rotary laser scanning and ultrasonic ranging.

    PubMed

    Wu, Jun; Zhu, Jigui; Yu, Zhijing; Zhuge, Jingchang; Xue, Bin

    2016-11-01

    Total station spatial coordinator measuring technology is extensively applied in the large-scale measurement of industrial assembly and manufacturing for its flexibility and adaptability. The existing total station technology has some principal limits such as poor efficiency and single tasking; in order to achieve the total station spatial coordinator measuring technology with the advantages of multi-task, real-time measurement, and high accuracy, this paper presents a novel total station measurement method by using multi-laser plane constraints established through rotating planar planes and distance information obtained with an ultrasonic ranging method. With the spatial divergence angles of the optoelectronic scanning and ultrasonic arrays, this method can measure the spatial coordinates in multi-task and real-time with a single station and a portable target bar. Experimental results show that the proposed method is feasible and valid with satisfactory accuracy. The maximum distance measurement error is less than 0.2 mm in a volume that is 5 m far away from the station.

  17. A subcarrier-pair based resource allocation scheme using proportional fairness for cooperative OFDM-based cognitive radio networks.

    PubMed

    Ma, Yongtao; Zhou, Liuji; Liu, Kaihua

    2013-08-09

    The paper presents a joint subcarrier-pair based resource allocation algorithm in order to improve the efficiency and fairness of cooperative multiuser orthogonal frequency division multiplexing (MU-OFDM) cognitive radio (CR) systems. A communication model where one source node communicates with one destination node assisted by one half-duplex decode-and-forward (DF) relay is considered in the paper. An interference-limited environment is considered, with the constraint of transmitted sum-power over all channels and aggregate average interference towards multiple primary users (PUs). The proposed resource allocation algorithm is capable of maximizing both the system transmission efficiency and fairness among secondary users (SUs). Besides, the proposed algorithm can also keep the interference introduced to the PU bands below a threshold. A proportional fairness constraint is used to assure that each SU can achieve a required data rate, with quality of service guarantees. Moreover, we extend the analysis to the scenario where each cooperative SU has no channel state information (CSI) about non-adjacent links. We analyzed the throughput and fairness tradeoff in CR system. A detailed analysis of the performance of the proposed algorithm is presented with the simulation results.

  18. A Subcarrier-Pair Based Resource Allocation Scheme Using Proportional Fairness for Cooperative OFDM-Based Cognitive Radio Networks

    PubMed Central

    Ma, Yongtao; Zhou, Liuji; Liu, Kaihua

    2013-01-01

    The paper presents a joint subcarrier-pair based resource allocation algorithm in order to improve the efficiency and fairness of cooperative multiuser orthogonal frequency division multiplexing (MU-OFDM) cognitive radio (CR) systems. A communication model where one source node communicates with one destination node assisted by one half-duplex decode-and-forward (DF) relay is considered in the paper. An interference-limited environment is considered, with the constraint of transmitted sum-power over all channels and aggregate average interference towards multiple primary users (PUs). The proposed resource allocation algorithm is capable of maximizing both the system transmission efficiency and fairness among secondary users (SUs). Besides, the proposed algorithm can also keep the interference introduced to the PU bands below a threshold. A proportional fairness constraint is used to assure that each SU can achieve a required data rate, with quality of service guarantees. Moreover, we extend the analysis to the scenario where each cooperative SU has no channel state information (CSI) about non-adjacent links. We analyzed the throughput and fairness tradeoff in CR system. A detailed analysis of the performance of the proposed algorithm is presented with the simulation results. PMID:23939586

  19. The Effect of Cooperative Learning Approach Based on Conceptual Change Condition on Students' Understanding of Chemical Equilibrium Concepts

    ERIC Educational Resources Information Center

    Bilgin, Ibrahim; Geban, Omer

    2006-01-01

    The purpose of this study is to investigate the effects of the cooperative learning approach based on conceptual change conditions over traditional instruction on 10th grade students' conceptual understanding and achievement of computational problems related to chemical equilibrium concepts. The subjects of this study consisted of 87 tenth grade…

  20. The Effects of CBI Lesson Sequence Type and Field Dependence on Learning from Computer-Based Cooperative Instruction in Web

    ERIC Educational Resources Information Center

    Ipek, Ismail

    2010-01-01

    The purpose of this study was to investigate the effects of CBI lesson sequence type and cognitive style of field dependence on learning from Computer-Based Cooperative Instruction (CBCI) in WEB on the dependent measures, achievement, reading comprehension and reading rate. Eighty-seven college undergraduate students were randomly assigned to…