WorldWideScience

Sample records for allowed outage times

  1. Optimization of Allowed Outage Time and Surveillance Test Intervals

    Energy Technology Data Exchange (ETDEWEB)

    Al-Dheeb, Mujahed; Kang, Sunkoo; Kim, Jonghyun [KEPCO international nuclear graduate school, Ulsan (Korea, Republic of)

    2015-10-15

    The primary purpose of surveillance testing is to assure that the components of standby safety systems will be operable when they are needed in an accident. By testing these components, failures can be detected that may have occurred since the last test or the time when the equipment was last known to be operational. The probability a system or system component performs a specified function or mission under given conditions at a prescribed time is called availability (A). Unavailability (U) as a risk measure is just the complementary probability to A(t). The increase of U means the risk is increased as well. D and T have an important impact on components, or systems, unavailability. The extension of D impacts the maintenance duration distributions for at-power operations, making them longer. This, in turn, increases the unavailability due to maintenance in the systems analysis. As for T, overly-frequent surveillances can result in high system unavailability. This is because the system may be taken out of service often due to the surveillance itself and due to the repair of test-caused failures of the component. The test-caused failures include those incurred by wear and tear of the component due to the surveillances. On the other hand, as the surveillance interval increases, the component's unavailability will grow because of increased occurrences of time-dependent random failures. In that situation, the component cannot be relied upon, and accordingly the system unavailability will increase. Thus, there should be an optimal component surveillance interval in terms of the corresponding system availability. This paper aims at finding the optimal T and D which result in minimum unavailability which in turn reduces the risk. Applying the methodology in section 2 to find the values of optimal T and D for two components, i.e., safety injection pump (SIP) and turbine driven aux feedwater pump (TDAFP). Section 4 is addressing interaction between D and T. In general

  2. A study on assessment methodology of surveillance test interval and allowed outage time

    Energy Technology Data Exchange (ETDEWEB)

    Che, Moo Seong; Cheong, Chang Hyeon; Lee, Byeong Cheol [Seoul Nationl Univ., Seoul (Korea, Republic of)] (and others)

    1996-07-15

    The objectives of this study is the development of methodology by which assessing the optimizes Surveillance Test Interval(STI) and Allowed Outage Time(AOT) using PSA method that can supplement the current deterministic methods and the improvement of Korea nuclear power plants safety. In the first year of this study, the survey about the assessment methodologies, modeling and results performed by domestic and international researches is performed as the basic step before developing the assessment methodology of this study. The assessment methodology that supplement the revealed problems in many other studies is presented and the application of new methodology into the example system assures the feasibility of this method.

  3. Evaluation of allowed outage times (AOTs) from a risk and reliability standpoint

    Energy Technology Data Exchange (ETDEWEB)

    Vesely, W.E. (Science Applications International Corp., Columbus, OH (USA))

    1989-08-01

    This report describes the basic risks which are associated with allowed outage times (AOTs), defines strategies for selecting the risks to be quantified, and describes how the risks can be quantified. The report furthermore describes criteria considerations in determining the acceptability of calculated AOT risks, and discusses the merits of relative risk criteria versus absolute risk criteria. The detailed evaluations which are involved in calculating AOT risks, including uncertainty considerations are also discussed. The report also describes the proper ways that risks from multiple AOTs should be considered so that risks are properly accumulated from proposed multiple AOT changes, but are not double-counted. Generally, average AOT risks which include the frequency of occurrence of the AOT need to be accumulated but single downtime risks don't since they apply to individual AOTs. 8 refs., 22 tabs.

  4. Risk-Based Allowed Outage Time and Surveillance Test Interval Extensions for Angra 1

    Directory of Open Access Journals (Sweden)

    Sonia M. Orlando Gibelli

    2012-01-01

    Full Text Available In this work, Probabilistic Safety Assessment (PSA is used to evaluate Allowed Outage Times (AOT and Surveillance Test Intervals (STI extensions for three Angra 1 nuclear power plant safety systems. The interest in such an analysis lies on the fact that PSA comprises a risk-based tool for safety evaluation and has been increasingly applied to support both the regulatory and the operational decision-making processes. Regarding Angra 1, among other applications, PSA is meant to be an additional method that can be used by the utility to justify Technical Specification relaxation to the Brazilian regulatory body. The risk measure used in this work is the Core Damage Frequency, obtained from the Angra 1 Level 1 PSA study. AOT and STI extensions are evaluated for the Safety Injection, Service Water and Auxiliary Feedwater Systems using the SAPHIRE code. In order to compensate for the risk increase caused by the extensions, compensatory measures as (1 test of redundant train prior to entering maintenance and (2 staggered test strategy are proposed. Results have shown that the proposed AOT extensions are acceptable for two of the systems with the implementation of compensatory measures whereas STI extensions are acceptable for all three systems.

  5. A study on assessment methodology of surveillance test interval and Allowed Outage Time

    Energy Technology Data Exchange (ETDEWEB)

    Che, Moo Seong; Cheong, Chang Hyeon; Ryu, Yeong Woo; Cho, Jae Seon; Heo, Chang Wook; Kim, Do Hyeong; Kim, Joo Yeol; Kim, Yun Ik; Yang, Hei Chang [Seoul National Univ., Seoul (Korea, Republic of)

    1997-07-15

    Objectives of this study is the development of methodology by which assesses the optimization of Surveillance Test Interval(STI) and Allowed Outage Time(AOT) using PSA method that can supplement the current deterministic methods and the improvement of Korean nuclear power plants safety. In the first year of this study, the survey about the assessment methodologies, modeling and results performed by domestic and international researches are performed as the basic step before developing the assessment methodology of this study. The assessment methodology that supplement the revealed problems in many other studies is presented and the application of new methodology into the example system assures the feasibility of this method. In the second year of this study, the sensitivity analyses about the failure factors of the components are performed in the bases of the assessment methodologies of the first study, the interaction modeling of the STI and AOT is quantified. And the reliability assessment methodology about the diesel generator is reviewed and applied to the PSA code.

  6. A study on assessment methodology of surveillance test interval and allowed outage time

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Chang Hyun; You, Young Woo; Cho, Jae Seon; Huh, Chang Wook; Kim, Do Hyoung; Kim, Ju Youl; Kim, Yoon Ik; Yang, Hui Chang; Park, Kang Min [Seoul National Univ., Seoul (Korea, Republic of)

    1998-03-15

    The objectives of this study is the development of methodology by which assesses the optimization of Surveillance Test Internal(STI) and Allowed Outage Time(AOT) using PSA method that can supplement the current deterministic methods and the improvement of Korean nuclear power plant safety. In this study, the survey about the assessment methodologies, modelings and results performed by domestic and international researches are performed as the basic step before developing the assessment methodology of this study. The assessment methodology that supplement the revealed problems in many other studies is presented and the application of new methodology into the example system assures the feasibility of this method. The sensitivity analyses about the failure factors of the components are performed in the bases of the and AOT is quantified. And the reliability assessment methodology about the diesel generator is reviewed and applied to the PSA code. The qualitative assessment for the STI/AOR of RPS/ESFAS assured safety the most important system in the nuclear power plant are performed.

  7. Quantification of risk considering external events on the change of allowed outage time and the preventive maintenance during power operation

    Energy Technology Data Exchange (ETDEWEB)

    Kang, D. J.; Kim, K. Y.; Yang, J. E

    2001-03-01

    In this study, for the major safety systems of Ulchin Units 3/4, we quantify the risk on the change of AOT and the PM during power operation to identify the effects on the results of external events PSA when nuclear power plant changes such as allowed outage time are requested. The systems for which the risks on the change of allowed outage time are quantified are High Pressure Safety Injection System (HPSIS), Containment Spray System (CSS), and Emergency Diesel Generator (EDG). The systems for which the risks on the PM during power operation are Low Pressure Safety Injection System (LPSIS), CSS, EDG, Essential Service Water System (ESWS). Following conclusions can be obtained through this study: 1)The increase of core damage frequency ({delta}CDF) on the change of AOT and the conditional core damage probability (CCDP) on the on-line PM of each system are differently quantified according to the cases of considering only internal events or only external events. . 2)It is expected that the quantification of risk including internal and external events is advantageous for the licensee of NPP if the regulatory acceptance criteria for the technical specification changes are relatively set up. However, it is expected to be disadvantageous for the licensee if the acceptance criteria are absolutely set up. 3)It is expected that the conduction on the quantification of only a fire event is sufficient when the quantification of external events PSA model is required for the plant changes of Korea Standard NPPs. 4)It is expected that the quantification of the increase of core damage frequency and the incremental conditional core damage probability on technical specification changes are not needed if the quantification results of those considering only internal events are below regulatory acceptance criteria and the external events PSA results are not greatly affected by the system availability. However, it is expected that the quantification of risk considering external events

  8. Distribution of time between unscheduled outages

    Energy Technology Data Exchange (ETDEWEB)

    Jaech, J.L.; Burke, R.C.

    1963-01-02

    A study is in progress in which reactor operations will be simulated on the computer, the primary purpose being to evaluate the costs associated with various administrative alternatives which may be followed in conducting the overall operation, in addition to defining how operational costs are affected by such things as changes in fuel quality. The problem is complicated by the fact that the operation of the reactors is largely affected by random occurrences; no one can predict exactly when a tube will leak, or when a rupture will occur. Therefore, basic to the study is a probabilistic function, or set of functions, which govern the random aspects of reactor outages, and which can be used in the simulation study to generate reactor outages. This report is concerned with the derivation of such probabilistic functions. Although derived specifically for the simulation study, they are deemed of sufficient interest to warrant a separate report. Similar documents will be issued from time to time as the study progresses, and as results are found which are considered worthy of reporting prior to completion of the study.

  9. Outage probability of a relay strategy allowing intra-link errors utilizing Slepian-Wolf theorem

    Science.gov (United States)

    Cheng, Meng; Anwar, Khoirul; Matsumoto, Tad

    2013-12-01

    In conventional decode-and-forward (DF) one-way relay systems, a data block received at the relay node is discarded, if the information part is found to have errors after decoding. Such errors are referred to as intra-link errors in this article. However, in a setup where the relay forwards data blocks despite possible intra-link errors, the two data blocks, one from the source node and the other from the relay node, are highly correlated because they were transmitted from the same source. In this article, we focus on the outage probability analysis of such a relay transmission system, where source-destination and relay-destination links, Link 1 and Link 2, respectively, are assumed to suffer from the correlated fading variation due to block Rayleigh fading. The intra-link is assumed to be represented by a simple bit-flipping model, where some of the information bits recovered at the relay node are the flipped version of their corresponding original information bits at the source. The correlated bit streams are encoded separately by the source and relay nodes, and transmitted block-by-block to a common destination using different time slots, where the information sequence transmitted over Link 2 may be a noise-corrupted interleaved version of the original sequence. The joint decoding takes place at the destination by exploiting the correlation knowledge of the intra-link (source-relay link). It is shown that the outage probability of the proposed transmission technique can be expressed by a set of double integrals over the admissible rate range, given by the Slepian-Wolf theorem, with respect to the probability density function ( pdf) of the instantaneous signal-to-noise power ratios (SNR) of Link 1 and Link 2. It is found that, with the Slepian-Wolf relay technique, so far as the correlation ρ of the complex fading variation is | ρ|outage curve converges to 1 when the bit streams are not fully correlated. Moreover, the Slepian-Wolf outage probability is proved

  10. Investigation of Suitability of Cascading Outage Assessment Methods for Real-Time Assessment

    DEFF Research Database (Denmark)

    Petersen, Pauli Fríðheim; Jóhannsson, Hjörtur; Nielsen, Arne Hejde

    of the method to real-time assessment. The investigation revealed that two of the methods are of special interest for further study on real-time assessment of cascading outages. These are the betweenness centrality model, based on network topology, and the manchester model, based on AC power flow.......This paper investigates the suitability of assessment methods for cascading outages for real-time assessment. A total of ten assessment methods for cascading outages are investigated, and for all of the investigated methods a complexity assessment is performed to assess the suitability...

  11. Power Outages

    Science.gov (United States)

    ... Thunderstorms & Lightning Tornadoes Tsunamis Volcanoes Wildfires Main Content Power Outages This page provides basic safety tips and ... during and after a power outage. Before a Power Outage Build or restock your emergency preparedness kit , ...

  12. Time management challenges of major refurbishment projects : An analysis of 20 hydropower outages at Fortum

    OpenAIRE

    Nyqvist, Daniel

    2015-01-01

    While most western hydropower sites are already developed or protected by legislation, the aging hydropower park requires refurbishment actions. Especially to tackle the challenges of an increased fluctuation at the grid coming from the expansion of other renewable energy sources such as wind power. The company Fortum is carrying out a number of major refurbishment projects every year and want to enhance their time performance during the outage. Delayed projects are resulting in unexpected co...

  13. Outage Analysis of Cooperative Transmission with Energy Harvesting Relay: Time Switching versus Power Splitting

    Directory of Open Access Journals (Sweden)

    Guanyao Du

    2015-01-01

    Full Text Available This paper investigates the multiuser transmission network with an energy harvesting (EH cooperative relay, where a source transmits independent information to multiple destinations with the help of an energy constrained relay. The relay can harvest energy from the radio frequency (RF signals transmitted from the source, and it helps the multiuser transmission only by consuming the harvested energy. By adopting the time switching and the power splitting relay receiver architectures, we firstly propose two protocols, the time switching cooperative multiuser transmission (TSCMT protocol and the power splitting cooperative multiuser transmission (PSCMT protocol, to enable the simultaneous information processing and EH at the relay for the system. To evaluate the system performance, we theoretically analyze the system outage probability for the two proposed protocols and then derive explicit expressions for each of them, respectively. Numerical results are provided to demonstrate the accuracy of our analytical results and reveal that compared with traditional noncooperative scheme our proposed protocols are green solutions to offer reliable communication and lower system outage probability without consuming additional energy. In particular, for the same transmit power at the source, the PSCMT protocol is superior to the TSCMT protocol to obtain lower system outage probability.

  14. Improvement of availability of PWR nuclear plants through the reduction of the time required for refueling/maintenance outages

    Energy Technology Data Exchange (ETDEWEB)

    Mayers, J.B.; Soth, L.G.

    1978-04-01

    The objective of the project, conducted by Commonwealth Research Corporation and Westinghouse Electric Corporation, is to identify improvements in procedures and equipment which will reduce the time required for refueling/maintenance outages at PWR nuclear power plants. The outage of Commonwealth Edison Zion Station Unit 1 in March through May of 1976 was evaluated to identify those items which caused delays and those work activities that offer the potential for significant improvements that could reduce the overall duration of the outage and achieve an improvement in the plant's availability for power production. Modifications in procedures have been developed and were evaluated during one or more outages in 1977. Conceptual designs have been developed for equipment modifications to the refueling system that could reduce the time required for the refueling portion of the outage. The purpose of the interim report is to describe those conceptual designs and to assess their impact upon future outages. Recommendations are included for the implementation of these equipment improvements in a continuation of this program as a demonstration of plant availability benefits that can be realized in PWR nuclear plants already in operation or under construction.

  15. GUIDELINES FOR IMPLEMENTATION OF AN ADVANCED OUTAGE CONTROL CENTER TO IMPROVE OUTAGE COORDINATION, PROBLEM RESOLUTION, AND OUTAGE RISK MANAGEMENT

    Energy Technology Data Exchange (ETDEWEB)

    Germain, Shawn St; Farris, Ronald; Whaley, April M; Medema, Heather; Gertman, David

    2014-09-01

    This research effort is a part of the Light-Water Reactor Sustainability (LWRS) Program, which is a research and development (R&D) program sponsored by Department of Energy (DOE) and performed in close collaboration with industry R&D programs that provide the technical foundations for licensing and managing the long-term, safe, and economical operation of current nuclear power plants. The LWRS program serves to help the U.S. nuclear industry adopt new technologies and engineering solutions that facilitate the continued safe operation of the plants and extension of the current operating licenses. Managing NPP outages is a complex and difficult task due to the large number of maintenance and repair activities that are accomplished in a short period of time. During an outage, the outage control center (OCC) is the temporary command center for outage managers and provides several critical functions for the successful execution of the outage schedule. Essentially, the OCC functions to facilitate information inflow, assist outage management in processing information, and to facilitate the dissemination of information to stakeholders. Currently, outage management activities primarily rely on telephone communication, face to face reports of status, and periodic briefings in the OCC. It is a difficult task to maintain current the information related to outage progress and discovered conditions. Several advanced communication and collaboration technologies have shown promise for facilitating the information flow into, across, and out of the OCC. The use of these technologies will allow information to be shared electronically, providing greater amounts of real-time information to the decision makers and allowing OCC coordinators to meet with supporting staff remotely. Passively monitoring status electronically through advances in the areas of mobile worker technologies, computer-based procedures, and automated work packages will reduce the current reliance on manually

  16. Technology Integration Initiative In Support of Outage Management

    Energy Technology Data Exchange (ETDEWEB)

    Gregory Weatherby; David Gertman

    2012-07-01

    Plant outage management is a high priority concern for the nuclear industry from cost and safety perspectives. Often, command and control during outages is maintained in the outage control center where many of the underlying technologies supporting outage control are the same as those used in the 1980’s. This research reports on the use of advanced integrating software technologies and hand held mobile devices as a means by which to reduce cycle time, improve accuracy, and enhance transparency among outage team members. This paper reports on the first phase of research supported by the DOE Light Water Reactor Sustainability (LWRS) Program that is performed in close collaboration with industry to examine the introduction of newly available technology allowing for safe and efficient outage performance. It is thought that this research will result in: improved resource management among various plant stakeholder groups, reduced paper work, and enhanced overall situation awareness for the outage control center management team. A description of field data collection methods, including personnel interview data, success factors, end-user evaluation and integration of hand held devices in achieving an integrated design are also evaluated. Finally, the necessity of obtaining operations cooperation support in field studies and technology evaluation is acknowledged.

  17. Improvement of availability of PWR nuclear plants through the reduction of the time required for refueling/maintenance outages, Phase 1. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, C.A.

    1978-08-01

    The objective of this project is to identify improvements in procedures and equipment which will reduce the time required for refueling/maintenance outages at PWR nuclear power plants. The outage of Commonwealth Edison Zion Station Unit 1 in March through May of 1976 was evaluated to identify those items which caused delays and those work activities that offer the potential for significant improvements toward reducing its overall duration. Thus, the plant's availability for power production would be increased. Revisions in procedures and some equipment modifications were implemented and evaluated during the Zion Unit 2 refueling/maintenance outage beginning in January 1977. Analysis of the observed data has identified benefits available through improved refueling equipment and also areas where additional new, innovative refueling, or refueling-related equipment should be beneficial. A number of specific design concepts are recommended as a result of Phase 1. In addition, a new master planning mechanism is described for implementation during subsequent planned outages at Zion Station. This final report describes the recommended conceptual designs and planning mechanism and assesses their impact upon future outages. Their effect on savings in refueling time, labor, and radiation exposure is discussed. The estimated economic payoff for these concepts was found to be of such significance that an additional phase of the program is warranted. During this extended phase, a more detailed engineering study should be undertaken to determine the cost of implementation along with more specific estimates of the benefits for PWR plants already in operation or under construction.

  18. Multicast Capacity Scaling of Wireless Networks with Multicast Outage

    CERN Document Server

    Liu, Chun-Hung

    2010-01-01

    Multicast transmission has several distinctive traits as opposed to more commonly studied unicast networks. Specially, these include (i) identical packets must be delivered successfully to several nodes, (ii) outage could simultaneously happen at different receivers, and (iii) the multicast rate is dominated by the receiver with the weakest link in order to minimize outage and retransmission. To capture these key traits, we utilize a Poisson cluster process consisting of a distinct Poisson point process (PPP) for the transmitters and receivers, and then define the multicast transmission capacity (MTC) as the maximum achievable multicast rate times the number of multicast clusters per unit volume, accounting for outages and retransmissions. Our main result shows that if $\\tau$ transmission attempts are allowed in a multicast cluster, the MTC is $\\Theta\\left(\\rho k^{x}\\log(k)\\right)$ where $\\rho$ and $x$ are functions of $\\tau$ depending on the network size and density, and $k$ is the average number of the inte...

  19. Outage Analysis of Spectrum-Sharing over M-Block Fading with Sensing Information

    KAUST Repository

    Alabbasi, Abdulrahman

    2016-07-13

    Future wireless technologies, such as, 5G, are expected to support real-time applications with high data throughput, e.g., holographic meetings. From a bandwidth perspective, cognitive radio is a promising technology to enhance the system’s throughput via sharing the licensed spectrum. From a delay perspective, it is well known that increasing the number of decoding blocks will improve the system robustness against errors, while increasing the delay. Therefore, optimally allocating the resources to determine the tradeoff of tuning the length of decoding blocks while sharing the spectrum is a critical challenge for future wireless systems. In this work, we minimize the targeted outage probability over the block-fading channels while utilizing the spectrum-sharing concept. The secondary user’s outage region and the corresponding optimal power are derived, over twoblocks and M-blocks fading channels. We propose two suboptimal power strategies and derive the associated asymptotic lower and upper bounds on the outage probability with tractable expressions. These bounds allow us to derive the exact diversity order of the secondary user’s outage probability. To further enhance the system’s performance, we also investigate the impact of including the sensing information on the outage problem. The outage problem is then solved via proposing an alternating optimization algorithm, which utilizes the verified strict quasiconvex structure of the problem. Selected numerical results are presented to characterize the system’s behavior and show the improvements of several sharing concepts.

  20. Progress Report on Alloy 617 Time Dependent Allowables

    Energy Technology Data Exchange (ETDEWEB)

    Wright, Julie Knibloe [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-06-01

    Time dependent allowable stresses are required in the ASME Boiler and Pressure Vessel Code for design of components in the temperature range where time dependent deformation (i.e., creep) is expected to become significant. There are time dependent allowable stresses in Section IID of the Code for use in the non-nuclear construction codes, however, there are additional criteria that must be considered in developing time dependent allowables for nuclear components. These criteria are specified in Section III NH. St is defined as the lesser of three quantities: 100% of the average stress required to obtain a total (elastic, plastic, primary and secondary creep) strain of 1%; 67% of the minimum stress to cause rupture; and 80% of the minimum stress to cause the initiation of tertiary creep. The values are reported for a range of temperatures and for time increments up to 100,000 hours. These values are determined from uniaxial creep tests, which involve the elevated temperature application of a constant load which is relatively small, resulting in deformation over a long time period prior to rupture. The stress which is the minimum resulting from these criteria is the time dependent allowable stress St. In this report data from a large number of creep and creep-rupture tests on Alloy 617 are analyzed using the ASME Section III NH criteria. Data which are used in the analysis are from the ongoing DOE sponsored high temperature materials program, form Korea Atomic Energy Institute through the Generation IV VHTR Materials Program and historical data from previous HTR research and vendor data generated in developing the alloy. It is found that the tertiary creep criterion determines St at highest temperatures, while the stress to cause 1% total strain controls at low temperatures. The ASME Section III Working Group on Allowable Stress Criteria has recommended that the uncertainties associated with determining the onset of tertiary creep and the lack of significant

  1. Secrecy Outage Capacity of Fading Channels

    CERN Document Server

    Gungor, Onur; Koksal, C Emre; Gamal, Hesham El; Shroff, Ness B

    2011-01-01

    This paper considers point to point secure communication over flat fading channels under an outage constraint. More specifically, we extend the definition of outage capacity to account for the secrecy constraint and obtain sharp characterizations of the corresponding fundamental limits under two different assumptions on the transmitter CSI (Channel state information). First, we find the outage secrecy capacity assuming that the transmitter has perfect knowledge of the legitimate and eavesdropper channel gains. In this scenario, the capacity achieving scheme relies on opportunistically exchanging private keys between the legitimate nodes. These keys are stored in a key buffer and later used to secure delay sensitive data using the Vernam's one time pad technique. We then extend our results to the more practical scenario where the transmitter is assumed to know only the legitimate channel gain. Here, our achievability arguments rely on privacy amplification techniques to generate secret key bits. In the two cas...

  2. Development of Improved Graphical Displays for an Advanced Outage Control Center, Employing Human Factors Principles for Outage Schedule Management

    Energy Technology Data Exchange (ETDEWEB)

    St Germain, Shawn Walter [Idaho National Lab. (INL), Idaho Falls, ID (United States); Farris, Ronald Keith [Idaho National Lab. (INL), Idaho Falls, ID (United States); Thomas, Kenneth David [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-09-01

    The long-term viability of existing nuclear power plants in the United States (U.S.) is dependent upon a number of factors, including maintaining high capacity factors, maintaining nuclear safety, and reducing operating costs, particularly those associated with refueling outages. Refueling outages typically take 20-30 days, and for existing light water NPPs in the U.S., the reactor cannot be in operation during the outage. Furthermore, given that many NPPs generate between $1-1.5 million/day in revenue when in operation, there is considerable interest in shortening the length of refueling outages. Yet refueling outages are highly complex operations, involving multiple concurrent and dependent activities that are somewhat challenging to coordinate; therefore, finding ways to improve refueling outage performance, while maintaining nuclear safety has proven to be difficult. The Advanced Outage Control Center (AOCC) project is a research and development (R&D) demonstration activity under the LWRS Program. LWRS is an R&D program that works closely with industry R&D programs to establish technical foundations for the licensing and managing of long-term, safe, and economical operation of current fleet of NPPs. As such, the LWRS Advanced Outage Control Center project has the goal of improving the management of commercial NPP refueling outages. To accomplish this goal, INL is developing an advanced outage control center (OCC) that is specifically designed to maximize the usefulness of communication and collaboration technologies for outage coordination and problem resolution activities. The overall focus is on developing an AOCC with the following capabilities that enables plant and OCC staff to; Collaborate in real-time to address emergent issues; Effectively communicate outage status to all workers involved in the outage; Effectively communicate discovered conditions in the field to the OCC; Provide real-time work status; Provide automatic pending support notifications

  3. Evaluation of Distribution Network Customer Outage Costs

    Science.gov (United States)

    Zemīte, Laila; Gerhards, Jānis

    2009-01-01

    Customer outage cost criteria are considered, collected and analyzed outage costs in Latvia distribution network, as well as distribution network outage elimination structure, the most common outage causes, are proposed outage costs estimation model. Finally the discussion of results of expected customer outage costs and interrupted energy assessment rate calculation results in Latvia distribution network in 2007 are presented, based on customers' mean value of incomes, outcomes and profitability.

  4. Outage management: A case study

    Energy Technology Data Exchange (ETDEWEB)

    Haber, S.B.; Barriere, M.T. (Brookhaven National Lab., Upton, NY (United States)); Roberts, K.H. (California Univ., Berkeley, CA (United States). Walter A. Haas School of Business)

    1992-01-01

    Outage management issues identified from a field study conducted at a two-unit commercial pressurized water reactor (PWR), when one unit was in a refueling outage and the other unit was at full power operation, are the focus of this paper. The study was conduced as part of the US Nuclear Regulatory Commission's (NRC) organizational factors research program, and therefore the issues to be addressed are from an organizational perspective. Topics discussed refer to areas identified by the NRC as critical for safety during shutdown operations, including outage planning and control, personnel stress, and improvements in training and procedures. Specifically, issues in communication, management attention, involvement and oversight, administrative processes, organizational culture, and human resources relevant to each of the areas are highlighted by example from field data collection. Insights regarding future guidance in these areas are presented based upon additional data collection subsequent to the original study.

  5. Outage management: A case study

    Energy Technology Data Exchange (ETDEWEB)

    Haber, S.B.; Barriere, M.T. [Brookhaven National Lab., Upton, NY (United States); Roberts, K.H. [California Univ., Berkeley, CA (United States). Walter A. Haas School of Business

    1992-09-01

    Outage management issues identified from a field study conducted at a two-unit commercial pressurized water reactor (PWR), when one unit was in a refueling outage and the other unit was at full power operation, are the focus of this paper. The study was conduced as part of the US Nuclear Regulatory Commission`s (NRC) organizational factors research program, and therefore the issues to be addressed are from an organizational perspective. Topics discussed refer to areas identified by the NRC as critical for safety during shutdown operations, including outage planning and control, personnel stress, and improvements in training and procedures. Specifically, issues in communication, management attention, involvement and oversight, administrative processes, organizational culture, and human resources relevant to each of the areas are highlighted by example from field data collection. Insights regarding future guidance in these areas are presented based upon additional data collection subsequent to the original study.

  6. Outages planning; Planificacion de recargas

    Energy Technology Data Exchange (ETDEWEB)

    Blanquer, N.

    2010-07-01

    The reason of a nuclear power plant outage seems easy. Replace 1/3 of the total core fuel inside reactor for a new, store the old one in a pool and shuffle the rest 2/3 in other positions in the core to optimize fuel burn up. Also is needed to make the preventive, corrective and conservative maintenance, the selected design changes and the regulatory and technical requirements for equipment and systems. To make the plant outage strategy for all the above pack with nuclear safety not challenged is the objective of this article for the Spanish Nuclear Society magazine. (Author)

  7. Analysis of Fixed Outage Transmission Schemes: A Finer Look at the Full Multiplexing Point

    CERN Document Server

    Wu, Peng

    2007-01-01

    This paper studies the performance of transmission schemes that have rate that increases with average SNR while maintaining a fixed outage probability. This is in contrast to the classical Zheng-Tse diversity-multiplexing tradeoff (DMT) that focuses on increasing rate and decreasing outage probability. Three different systems are explored: antenna diversity systems, time/frequency diversity systems, and automatic repeat request (ARQ) systems. In order to accurately study performance in the fixed outage setting, it is necesary to go beyond the coarse, asymptotic multiplexing gain metric. In the case of antenna diversity and time/frequency diversity, an affine approximation to high SNR outage capacity (i.e., multiplexing gain plus a power/rate offset) accurately describes performance and shows the very significant benefits of diversity. ARQ is also seen to provide a significant performance advantage, but even an affine approximation to outage capacity is unable to capture this advantage and outage capacity must...

  8. Outage maintenance checks on large generator windings

    Energy Technology Data Exchange (ETDEWEB)

    Nindra, B.; Jeney, S.I.; Slobodinsky, Y. [National Electric Coil, Columbus, OH (United States)

    1995-12-31

    In the present days of austerity, more constraints and pressures are being brought on the maintenance engineers to certify the generators for their reliability and life extension. The outages are shorter and intervals between the outages are becoming longer. The annual outages were very common when utilities had no regulatory constraints and also had standby capacities. Furthermore, due to lean and mean budgets, outage maintenance programs are being pursued more aggressively, so that longer interval outages can be achieved to ensure peak generator performance. This paper will discuss various visual checks, electrical tests and recommended fixes to achieve the above mentioned objectives, in case any deficiencies are found.

  9. Outage Performance in Cognitive Radio Systems with Opportunistic Interference Cancelation

    DEFF Research Database (Denmark)

    Di Taranto, Rocco; Popovski, Petar

    2011-01-01

    transmitter. First, we investigate how the secondary transmitter, when using OIC and S-OIC for fixed transmitting power, should select its rate in order to meet its target outage probability under different assumptions about the channel-state-information available at the secondary transmitter. We study three...... different cases and for each of them identify the region of achievable primary and secondary rates. Second, we determine how the secondary transmitter should select its transmitting power not to violate the target outage probability at the primary terminals. Our numerical results show that the best......) and the interplay between the allowed power at the secondary transmitter (which depends on the target outage probability at the primary receiver) and the decodability at the secondary receiver....

  10. Minimizing forced outage risk in generator bidding

    Science.gov (United States)

    Das, Dibyendu

    Competition in power markets has exposed the participating companies to physical and financial uncertainties. Generator companies bid to supply power in a day-ahead market. Once their bids are accepted by the ISO they are bound to supply power. A random outage after acceptance of bids forces a generator to buy power from the expensive real-time hourly spot market and sell to the ISO at the set day-ahead market clearing price, incurring losses. A risk management technique is developed to assess this financial risk associated with forced outages of generators and then minimize it. This work presents a risk assessment module which measures the financial risk of generators bidding in an open market for different bidding scenarios. The day-ahead power market auction is modeled using a Unit Commitment algorithm and a combination of Normal and Cauchy distributions generate the real time hourly spot market. Risk profiles are derived and VaRs are calculated at 98 percent confidence level as a measure of financial risk. Risk Profiles and VaRs help the generators to analyze the forced outage risk and different factors affecting it. The VaRs and the estimated total earning for different bidding scenarios are used to develop a risk minimization module. This module will develop a bidding strategy of the generator company such that its estimated total earning is maximized keeping the VaR below a tolerable limit. This general framework of a risk management technique for the generating companies bidding in competitive day-ahead market can also help them in decisions related to building new generators.

  11. Development of Methodologies for Technology Deployment for Advanced Outage Control Centers that Improve Outage Coordination, Problem Resolution and Outage Risk Management

    Energy Technology Data Exchange (ETDEWEB)

    Shawn St. Germain; Ronald Farris; Heather Medeman

    2013-09-01

    schedule depends upon the performance of the outage management organization. During an outage, the outage control center (OCC) is the temporary command center for outage managers and provides several critical functions for the successful execution of the outage schedule. Essentially, the OCC functions to facilitate information inflow, assist outage management in processing information and to facilitate the dissemination of information to stakeholders. Currently, outage management activities primarily rely on telephone communication, face to face reports of status and periodic briefings in the OCC. Much of the information displayed in OCCs is static and out of date requiring an evaluation to determine if it is still valid. Several advanced communication and collaboration technologies have shown promise for facilitating the information flow into, across and out of the OCC. Additionally, advances in the areas of mobile worker technologies, computer based procedures and electronic work packages can be leveraged to improve the availability of real time status to outage managers.

  12. Analysis of the effects of communication and surveillance facility service outages on traffic separations.

    Science.gov (United States)

    Borener, Sherry S; Guzhva, Vitaly S

    2014-09-01

    This study examines air traffic separations in the service volumes of communication and surveillance facilities that experienced service outages. The data sample consists of 338 unscheduled service outages that happened in 2010 and 2011 at facilities located in the vicinity of 15 major traffic hubs. For each outage, radar track data were collected and used to calculate traffic separations during the period of 30 minutes before to 30 minutes after an outage. Then, the separation index, which indicates the percentage of horizontal separation retained between two aircraft at the same altitude, was estimated. The separation index and loss of separation events were analyzed using lognormal and negative binomial regression models. The results suggest that the count of separation events peaks during the 15 minutes after an outage. In addition, traffic collision avoidance system resolution advisory (TCAS RA) encounters and Category A separation events are 1.31 times more likely during the 30 minutes following the beginning of a service outage, as compared to the 30 minutes before the outage, for both types of facilities. Also, the separation index values are 19% lower following a surveillance facility outage and 4% lower following a communication facility service loss. This study provides evidence that unscheduled service outages of air traffic management facilities are associated with lost or reduced traffic separations and thus can be considered precursors to hazardous loss of separation events.

  13. 一种适用于可靠性评估的电网设备时变停运模型%A New Time-varying Component Outage Model for Power System Reliability Analysis

    Institute of Scientific and Technical Information of China (English)

    汲国强; 张伯明; 吴文传; 孙宏斌; 宁辽逸

    2013-01-01

    It is a fundamental work to develop accurate component outage model for reliability analysis in power system. The traditional outage model cannot reflect the impact of the time-varying factors in the operating conditions and the repair after failure. In this paper, a staircase function is used to approximate the deterioration failure rate curve and a renewal process based model is proposed to estimate time-varying failure probabilities. The proposed time-varying outage model can both reflect the effects on failure rate caused by both components' deterioration and repair activities in long terms. An example of a real transformer shows that the proposed model can precisely predict life cumulative probability distribution and steady state of availability. Compared to traditional constant model, the model proposed in this paper is more accurate and practical.%建立精确的元件停运模型是电力系统中长期可靠性评估的基础工作,现有的元件停运模型通常不能反映元件时变的运行工况和维修对元件的影响.采用阶梯函数来近似模拟元件老化故障率曲线,并基于更新过程理论建立了元件时变停运模型.该模型可以反映中长期可靠性评估中时间对老化故障率的增长效应和维修对老化故障率的降低效应.实际的变压器算例表明,该模型适合模拟任意老化故障率曲线,可用于老化模式已知的元件寿命分布函数和可用度稳态值的评估.相比于传统模型,所提模型具有更好的精度和更广的适用性.

  14. Outage capacity of multicarrier systems

    KAUST Repository

    Yilmaz, Ferkan

    2010-01-01

    The probability density function and the cumulative distribution function of the product of shifted Gamma variates are obtained in terms of the generalized Fox\\'s H function. Using these new results, the exact outage capacity of multi carrier transmission through a slow Nakagami-m fading channel is presented. Moreover, it is shown that analytical and simulation results are in perfect agreement. © 2009 IEEE.

  15. Underlay Cognitive Radio Systems with Improper Gaussian Signaling: Outage Performance Analysis

    KAUST Repository

    Amin, Osama

    2016-03-29

    Improper Gaussian signaling has the ability over proper (conventional) Gaussian signaling to improve the achievable rate of systems that suffer from interference. In this paper, we study the impact of using improper Gaussian signaling on the performance limits of the underlay cognitive radio system by analyzing the achievable outage probability of both the primary user (PU) and secondary user (SU). We derive the exact outage probability expression of the SU and construct upper and lower bounds of the PU outage probability which results in formulating an approximate expression of the PU outage probability. This allows us to design the SU signal by adjusting its transmitted power and the circularity coefficient to minimize the SU outage probability while maintaining a certain PU quality-of-service. Finally, we evaluate the derived expressions for both the SU and the PU and the corresponding adaptive algorithms by numerical results.

  16. Use of VIIRS DNB Data to Monitor Power Outages and Restoration for Significant Weather Events

    Science.gov (United States)

    Jedlovec, Gary; Molthan, Andrew

    2008-01-01

    NASA fs Short-term Prediction Research and Transition (SPoRT) project operates from NASA's Marshall Space Flight Center in Huntsville, Alabama. The team provides unique satellite data to the National Weather Service (NWS) and other agencies and organizations for weather analysis. While much of its work is focused on improving short-term weather forecasting, the SPoRT team supported damage assessment and response to Hurricane Superstorm Sandy by providing imagery that highlighted regions without power. The team used data from the Visible Infrared Imaging Radiometer Suite (VIIRS) on the Suomi National Polar-orbiting Partnership (Suomi NPP) satellite. The VIIRS low-light sensor, known as the day-night-band (DNB), can detect nighttime light from wildfires, urban and rural communities, and other human activity which emits light. It can also detect moonlight reflected from clouds and surface features. Using real time VIIRS data collected by our collaborative partner at the Space Science and Engineering Center of the University of Wisconsin, the SPoRT team created composite imagery to help detect power outages and restoration. This blackout imagery allowed emergency response teams from a variety of agencies to better plan and marshal resources for recovery efforts. The blackout product identified large-scale outages, offering a comprehensive perspective beyond a patchwork GIS mapping of outages that utility companies provide based on customer complaints. To support the relief efforts, the team provided its imagery to the USGS data portal, which the Federal Emergency Management Agency (FEMA) and other agencies used in their relief efforts. The team fs product helped FEMA, the U.S. Army Corps of Engineers, and U.S. Army monitor regions without power as part of their disaster response activities. Disaster responders used the images to identify possible outages and effectively distribute relief resources. An enhanced product is being developed and integrated into a web

  17. Outage analysis of blind cooperative diversity

    KAUST Repository

    Tourki, Kamel

    2011-06-06

    Mobile users with single antennas can still take advantage of spatial diversity through cooperative space-time-encoded transmission. In this paper, we considered a scheme in which a relay chooses to cooperate only if its source-relay channel is of an acceptable quality, and we evaluate the usefulness of relaying when the source acts blindly and ignores the decision of the relays whether they may cooperate or not. In our study, we consider the regenerative relays in which the decisions to cooperate are based on a targeted end-to-end data rate R. We derived the end-to-end outage probability for a transmission rate R and a code rate ρ and look at a power allocation strategy between the source and the relays in order to minimize the end-to-end outage probability at the destination for high signal-to-noise ratio, by using the golden section search method. Performance results show that the computer simulations-based results coincide with our analytical results. Copyright © 2011 John Wiley & Sons, Ltd.

  18. Does Your Domestic Photovoltaic Energy System Survive Grid Outages?

    Directory of Open Access Journals (Sweden)

    Marijn R. Jongerden

    2016-09-01

    Full Text Available Domestic renewable energy systems, including photovoltaic energy generation, as well as local storage, are becoming increasingly popular and economically feasible, but do come with a wide range of options. Hence, it can be difficult to match their specification to specific customer’s needs. Next to the usage-specific demand profiles and location-specific production profiles, local energy storage through the use of batteries is becoming increasingly important, since it allows one to balance variations in production and demand, either locally or via the grid. Moreover, local storage can also help to ensure a continuous energy supply in the presence of grid outages, at least for a while. Hybrid Petri net (HPN models allow one to analyze the effect of different battery management strategies on the continuity of such energy systems in the case of grid outages. The current paper focuses on one of these strategies, the so-called smart strategy, that reserves a certain percentage of the battery capacity to be only used in case of grid outages. Additionally, we introduce a new strategy that makes better use of the reserved backup capacity, by reducing the demand in the presence of a grid outage through a prioritization mechanism. This new strategy, called power-save, only allows the essential (high-priority demand to draw from the battery during power outages. We show that this new strategy outperforms previously-proposed strategies through a careful analysis of a number of scenarios and for a selection of survivability measures, such as minimum survivability per day, number of survivable hours per day, minimum survivability per year and various survivability quantiles.

  19. Cross-Layer Framework for Multiuser Real Time H.264/AVC Video Encoding and Transmission over Block Fading MIMO Channels Using Outage Probability

    Directory of Open Access Journals (Sweden)

    Slavche Pejoski

    2014-01-01

    Full Text Available We present a framework for cross-layer optimized real time multiuser encoding of video using a single layer H.264/AVC and transmission over MIMO wireless channels. In the proposed cross-layer adaptation, the channel of every user is characterized by the probability density function of its channel mutual information and the performance of the H.264/AVC encoder is modeled by a rate distortion model that takes into account the channel errors. These models are used during the resource allocation of the available slots in a TDMA MIMO communication system with capacity achieving channel codes. This framework allows for adaptation to the statistics of the wireless channel and to the available resources in the system and utilization of the multiuser diversity of the transmitted video sequences. We show the effectiveness of the proposed framework for video transmission over Rayleigh MIMO block fading channels, when channel distribution information is available at the transmitter.

  20. Seasonal and Local Characteristics of Lightning Outages of Power Distribution Lines in Hokuriku Area

    Science.gov (United States)

    Sugimoto, Hitoshi; Shimasaki, Katsuhiko

    The proportion of the lightning outages in all outages on Japanese 6.6kV distribution lines is high with approximately 20 percent, and then lightning protections are very important for supply reliability of 6.6kV lines. It is effective for the lightning performance to apply countermeasures in order of the area where a large number of the lightning outages occur. Winter lightning occurs in Hokuriku area, therefore it is also important to understand the seasonal characteristics of the lightning outages. In summer 70 percent of the lightning outages on distribution lines in Hokuriku area were due to sparkover, such as power wire breakings and failures of pole-mounted transformers. However, in winter almost half of lightning-damaged equipments were surge arrester failures. The number of the lightning outages per lightning strokes detected by the lightning location system (LLS) in winter was 4.4 times larger than that in summer. The authors have presumed the occurrence of lightning outages from lightning stroke density, 50% value of lightning current and installation rate of lightning protection equipments and overhead ground wire by multiple regression analysis. The presumed results suggest the local difference in the lightning outages.

  1. Use of collaboration software to improve nuclear power plant outage management

    Energy Technology Data Exchange (ETDEWEB)

    Germain, Shawn

    2015-02-01

    Nuclear Power Plant (NPP) refueling outages create some of the most challenging activities the utilities face in both tracking and coordinating thousands of activities in a short period of time. Other challenges, including nuclear safety concerns arising from atypical system configurations and resource allocation issues, can create delays and schedule overruns, driving up outage costs. Today the majority of the outage communication is done using processes that do not take advantage of advances in modern technologies that enable enhanced communication, collaboration and information sharing. Some of the common practices include: runners that deliver paper-based requests for approval, radios, telephones, desktop computers, daily schedule printouts, and static whiteboards that are used to display information. Many gains have been made to reduce the challenges facing outage coordinators; however; new opportunities can be realized by utilizing modern technological advancements in communication and information tools that can enhance the collective situational awareness of plant personnel leading to improved decision-making. Ongoing research as part of the Light Water Reactor Sustainability Program (LWRS) has been targeting NPP outage improvement. As part of this research, various applications of collaborative software have been demonstrated through pilot project utility partnerships. Collaboration software can be utilized as part of the larger concept of Computer-Supported Cooperative Work (CSCW). Collaborative software can be used for emergent issue resolution, Outage Control Center (OCC) displays, and schedule monitoring. Use of collaboration software enables outage staff and subject matter experts (SMEs) to view and update critical outage information from any location on site or off.

  2. Refueling outage availability study. Phase 1 final report

    Energy Technology Data Exchange (ETDEWEB)

    Thomasson, F.R.

    1977-11-01

    Babcock and Wilcox entered into a contract with the Department of Energy (formerly the Energy Research and Development Administration) for the performance of a refueling outage availability study with the cooperation of Duke Power Company and Arkansas Power and Light Company. The objective was to improve plant availability through reduction of refueling outage time. The conclusions of the study were drawn from data gathered during the 1976 Oconee 3 and 1977 Arkansas Unit One refueling outages. The onsite effort was one of observation and data recording, which included time-lapsed photography and video tape. The collected data were then evaluated and analyzed for potential improvements and to identify in detail where resources were consumed. The overall result was a listing of (1) specific recommendations for implementing improvements in the facilities, equipment, tools, procedures, and techniques for the participating utilities; (2) generic recommendations of immediate benefit to other applicable utilities; and (3) recommendations for further work in the succeeding phases of the DOE program. The results indicate that, by incorporating the recommendations and taking credit for the time savings, an ideal refueling outage length of 21 to 22 days for the nuclear steam system (NSS) could be realized. Additional benefits would be a reduction in man-Rem exposure and manpower requirements.

  3. 76 FR 33686 - Proposed Extension of Part 4 of the Commission's Rules Regarding Outage Reporting to...

    Science.gov (United States)

    2011-06-09

    ... expectations in American life and are fast becoming substitutes for communications services provided by older... Commission learns of major outages in a timely fashion and, at the same time, minimizes the amount of...

  4. An analytical model for evaluating outage and handover probability of cellular wireless networks

    CERN Document Server

    Decreusefond, Laurent; Vu, Than-Tung

    2010-01-01

    We consider stochastic cellular networks where base stations locations form a homogenous Poisson point process and each mobile is attached to the base station that provides the best mean signal power. The mobile is in outage if the SINR falls below some threshold. The handover decision has to be made if the mobile is in outage for some time slots. The outage probability and the handover probability is evaluated in taking into account the effect of path loss, shadowing, Rayleigh fast fading, frequency factor reuse and conventional beamforming. The main assumption is that the Rayleigh fast fading changes each time slot while other network components remain static during the period of study.

  5. A framework and review of customer outage costs: Integration and analysis of electric utility outage cost surveys

    Energy Technology Data Exchange (ETDEWEB)

    Lawton, Leora; Sullivan, Michael; Van Liere, Kent; Katz, Aaron; Eto, Joseph

    2003-11-01

    A clear understanding of the monetary value that customers place on reliability and the factors that give rise to higher and lower values is an essential tool in determining investment in the grid. The recent National Transmission Grid Study recognizes the need for this information as one of growing importance for both public and private decision makers. In response, the U.S. Department of Energy has undertaken this study, as a first step toward addressing the current absence of consistent data needed to support better estimates of the economic value of electricity reliability. Twenty-four studies, conducted by eight electric utilities between 1989 and 2002 representing residential and commercial/industrial (small, medium and large) customer groups, were chosen for analysis. The studies cover virtually all of the Southeast, most of the western United States, including California, rural Washington and Oregon, and the Midwest south and east of Chicago. All variables were standardized to a consistent metric and dollar amounts were adjusted to the 2002 CPI. The data were then incorporated into a meta-database in which each outage scenario (e.g., the lost of electric service for one hour on a weekday summer afternoon) is treated as an independent case or record both to permit comparisons between outage characteristics and to increase the statistical power of analysis results. Unadjusted average outage costs and Tobit models that estimate customer damage functions are presented. The customer damage functions express customer outage costs for a given outage scenario and customer class as a function of location, time of day, consumption, and business type. One can use the damage functions to calculate outage costs for specific customer types. For example, using the customer damage functions, the cost experienced by an ''average'' customer resulting from a 1 hour summer afternoon outage is estimated to be approximately $3 for a residential customer, $1

  6. Wooden hutch space allowance influences male Holstein calf health, performance, daily lying time, and respiratory immunity.

    Science.gov (United States)

    Calvo-Lorenzo, M S; Hulbert, L E; Fowler, A L; Louie, A; Gershwin, L J; Pinkerton, K E; Ballou, M A; Klasing, K C; Mitloehner, F M

    2016-06-01

    Dairy calves in the western United States are commonly raised individually in wooden hutches with a space allowance of 1.23m(2)/calf. Recent legislative initiatives in California and across the United States were passed regarding concern over space allowance for farm animals. The objective of this study was to determine if rearing male Holstein calves in wooden hutches modified to increase space allowance would influence measures of performance, lying time per day, health, and respiratory immunocompetence. At 4d of age, 60 calves were randomly assigned to 1 of 3housing treatments: (1) conventional housing (CONV; 1.23m(2)/calf), (2) 1.5 × CONV (MOD; 1.85m(2)/calf), or (3) 3 × CONV (MAX; 3.71m(2)/calf). Intakes of milk and solid feed were recorded daily and body weight was measured at 0, 3, 6, 10, and 12 wk of age. For the first 3 wk of the trial, calves were scored daily for fecal consistency, hydration, and hide cleanliness. In addition, calves were scored for respiratory health (i.e., nasal and eye discharge, ear position) until 7 wk of age. The total lying duration per day was recorded using data loggers at 3, 6, and 10 wk of age. Eight clinically healthy calves from each treatment were sensitized with subcutaneous ovalbumin (OVA) and then challenged with aerosolized OVA to assess calf respiratory immunity at 11 wk of age. Bronchoalveolar lavage fluid (BALF) was collected 4d after the OVA challenge and analyzed for leukocyte differentials and OVA-specific IgG, IgG1, IgA, and IgE. Calf average daily gain and body weight were positively associated with space allowance at approximately 3 wk before weaning and throughout postweaning, respectively. A greater space allowance decreased lying time after 46d. Space allowance did not influence fecal consistency, but there was a tendency for MAX calves to take 1d longer to recover from loose feces than MOD calves. The MAX calves had the fewest (%) observations with feces on their body compared with CONV or MOD. At 3 wk of

  7. Effectiveness of cell outage compensation in LTE networks

    NARCIS (Netherlands)

    Amirijoo, M.; Jorguseski, L.; Litjens, R.; Nascimento, R.

    2011-01-01

    Cell outage management is a self-healing functionality in future mobile cellular networks, aiming to automatically detect cell or site level outages (cell outage detection) as well as to mitigate as much as possible the caused degradation of coverage, capacity and/or service quality (cell outage com

  8. Status Report on the Development of Micro-Scheduling Software for the Advanced Outage Control Center Project

    Energy Technology Data Exchange (ETDEWEB)

    Germain, Shawn St. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Thomas, Kenneth [Idaho National Lab. (INL), Idaho Falls, ID (United States); Farris, Ronald [Idaho National Lab. (INL), Idaho Falls, ID (United States); Joe, Jeffrey [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2014-09-01

    The long-term viability of existing nuclear power plants (NPPs) in the United States (U.S.) is dependent upon a number of factors, including maintaining high capacity factors, maintaining nuclear safety, and reducing operating costs, particularly those associated with refueling outages. Refueling outages typically take 20-30 days, and for existing light water NPPs in the U.S., the reactor cannot be in operation during the outage. Furthermore, given that many NPPs generate between $1-1.5 million/day in revenue when in operation, there is considerable interest in shortening the length of refueling outages. Yet, refueling outages are highly complex operations, involving multiple concurrent and dependent activities that are difficult to coordinate. Finding ways to improve refueling outage performance while maintaining nuclear safety has proven to be difficult. The Advanced Outage Control Center project is a research and development (R&D) demonstration activity under the Light Water Reactor Sustainability (LWRS) Program. LWRS is a R&D program which works with industry R&D programs to establish technical foundations for the licensing and managing of long-term, safe, and economical operation of current NPPs. The Advanced Outage Control Center project has the goal of improving the management of commercial NPP refueling outages. To accomplish this goal, this INL R&D project is developing an advanced outage control center (OCC) that is specifically designed to maximize the usefulness of communication and collaboration technologies for outage coordination and problem resolution activities. This report describes specific recent efforts to develop a capability called outage Micro-Scheduling. Micro-Scheduling is the ability to allocate and schedule outage support task resources on a sub-hour basis. Micro-Scheduling is the real-time fine-tuning of the outage schedule to react to the actual progress of the primary outage activities to ensure that support task resources are

  9. Power Outage, Business Continuity and Businesses' Choices of Power Outage Mitigation Measures

    Directory of Open Access Journals (Sweden)

    Ali Asgary

    2011-01-01

    Full Text Available Problem statement: Power outage has been mentioned as one of the most experienced and perceived risks by various types of businesses and organizations. Thus, reducing the impacts of power outage has become a key agenda in business continuity planning. Back-up or stand-by generators are among the most well known measures taken by power consumers to tackle the power outage problem. Approach: A survey was conducted to understand various aspects of power outage and the impacts of power outrage on businesses. In addition a choice experiment method was used to derive businesses’ preferences for different power outage mitigation measures that would have a range of prices, space requirements, air and noise pollution as well as mobility attributes using a sample of Canadian businesses located in the . Sample was drawn from businesses operating in the Greater Toronto Area (GTA and surrounding communities in Ontario, Canada. Results: It was found that majority of businesses have experienced and unconvinced by power outage and consider it to be a major risk to their operations. Production loss, data loss, damage to equipment and loss of lighting are the most significant sources for inconveniences caused by the power outages. It was found that a considerable number of businesses have not taken appropriate measures to mitigate this risk. Estimations from the responses revealed that sample businesses had a positive willingness to pay for power outage reduction and that businesses prefer power outage mitigation measures that are least costly, have low levels of air and noise pollution and occupy smaller spaces respectively. Conclusion: An uninterrupted power supply is an important element of business continuity in today’s business world. Although many businesses are not fully prepared against power outages, they are willing to pay for low cost and low pollution power outage mitigation measures.

  10. New reconstruction algorithm allows shortened acquisition time for myocardial perfusion SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Valenta, Ines; Treyer, Valerie; Husmann, Lars; Gaemperli, Oliver; Schindler, Michael J.; Herzog, Bernhard A.; Veit-Heibach, Patrick; Pazhenkottil, Aju P.; Kaufmann, Philipp A. [University Hospital Zurich, Cardiac Imaging, Zurich (Switzerland); University of Zurich, Zurich Center for Integrative Human Physiology, Zurich (Switzerland); Buechel, Ronny R.; Nkoulou, Rene [University Hospital Zurich, Cardiac Imaging, Zurich (Switzerland)

    2010-04-15

    Shortening scan time and/or reducing radiation dose at maintained image quality are the main issues of the current research in radionuclide myocardial perfusion imaging (MPI). We aimed to validate a new iterative reconstruction (IR) algorithm for SPECT MPI allowing shortened acquisition time (HALF time) while maintaining image quality vs. standard full time acquisition (FULL time). In this study, 50 patients, referred for evaluation of known or suspected coronary artery disease by SPECT MPI using 99mTc-Tetrofosmin, underwent 1-day adenosine stress 300 MBq/rest 900 MBq protocol with standard (stress 15 min/rest 15 min FULL time) immediately followed by short emission scan (stress 9 min/rest 7 min HALF time) on a Ventri SPECT camera (GE Healthcare). FULL time scans were processed with IR, short scans were additionally processed with a recently developed software algorithm for HALF time emission scans. All reconstructions were subsequently analyzed using commercially available software (QPS/QGS, Cedars Medical Sinai) with/without X-ray based attenuation correction (AC). Uptake values (percent of maximum) were compared by regression and Bland-Altman (BA) analysis in a 20-segment model. HALF scans yielded a 96% readout and 100% clinical diagnosis concordance compared to FULL. Correlation for uptake in each segment (n = 1,000) was r = 0.87at stress (p < 0.001) and r = 0.89 at rest (p < 0.001) with respective BA limits of agreement of -11% to 10% and -12% to 11%. After AC similar correlation (r = 0.82, rest; r = 0.80, stress, both p < 0.001) and BA limits were found (-12% to 10%; -13% to 12%). With the new IR algorithm, SPECT MPI can be acquired at half of the scan time without compromising image quality, resulting in an excellent agreement with FULL time scans regarding to uptake and clinical conclusion. (orig.)

  11. Comparison and validation of statistical methods for predicting power outage durations in the event of hurricanes.

    Science.gov (United States)

    Nateghi, Roshanak; Guikema, Seth D; Quiring, Steven M

    2011-12-01

    This article compares statistical methods for modeling power outage durations during hurricanes and examines the predictive accuracy of these methods. Being able to make accurate predictions of power outage durations is valuable because the information can be used by utility companies to plan their restoration efforts more efficiently. This information can also help inform customers and public agencies of the expected outage times, enabling better collective response planning, and coordination of restoration efforts for other critical infrastructures that depend on electricity. In the long run, outage duration estimates for future storm scenarios may help utilities and public agencies better allocate risk management resources to balance the disruption from hurricanes with the cost of hardening power systems. We compare the out-of-sample predictive accuracy of five distinct statistical models for estimating power outage duration times caused by Hurricane Ivan in 2004. The methods compared include both regression models (accelerated failure time (AFT) and Cox proportional hazard models (Cox PH)) and data mining techniques (regression trees, Bayesian additive regression trees (BART), and multivariate additive regression splines). We then validate our models against two other hurricanes. Our results indicate that BART yields the best prediction accuracy and that it is possible to predict outage durations with reasonable accuracy.

  12. Cognitive Multiple-Antenna Network with Outage and Rate Margins at the Primary System

    DEFF Research Database (Denmark)

    Maham, Behrouz; Popovski, Petar

    2015-01-01

    formulas for the outage probability. Furthermore, the optimum transmit power in the secondary system is investigated for maximizing the ergodic capacity when there is an outage constraint at the primary system, and simple solutions are proposed. We then consider the case with rate adaptation at the primary...... interference from the downlink MISO cognitive radio, also called secondary system. We derive exact expressions for outage probability of the primary user under Rayleigh fading, when the primary system is exposed to interference from a secondary base station. We treat three different operating modes...... for the primary base station (BS): space-time coding, antenna selection, and beamforming, each of them with different channel information requirements. We first consider the case in which the primary BS uses a fixed rate and we analyze the outage probability. In high-SNR scenario, we derive closed-form asymptotic...

  13. Contingency Analysis of Cascading Line Outage Events

    Energy Technology Data Exchange (ETDEWEB)

    Thomas L Baldwin; Magdy S Tawfik; Miles McQueen

    2011-03-01

    As the US power systems continue to increase in size and complexity, including the growth of smart grids, larger blackouts due to cascading outages become more likely. Grid congestion is often associated with a cascading collapse leading to a major blackout. Such a collapse is characterized by a self-sustaining sequence of line outages followed by a topology breakup of the network. This paper addresses the implementation and testing of a process for N-k contingency analysis and sequential cascading outage simulation in order to identify potential cascading modes. A modeling approach described in this paper offers a unique capability to identify initiating events that may lead to cascading outages. It predicts the development of cascading events by identifying and visualizing potential cascading tiers. The proposed approach was implemented using a 328-bus simplified SERC power system network. The results of the study indicate that initiating events and possible cascading chains may be identified, ranked and visualized. This approach may be used to improve the reliability of a transmission grid and reduce its vulnerability to cascading outages.

  14. The four ``Ps`` of outage management

    Energy Technology Data Exchange (ETDEWEB)

    Kuehn, S.E.

    1996-01-01

    This article describes how planning, partnering, preparation and people prevent poor outage performance. Boasting the best production costs in a decade, the US fleet of nuclear reactors is performing better than ever. Industry wide, production costs fell 7% to $20.02 per net megawatt hour (MWh) and output climbed 3% to 634million MWh. It doesn`t take a nuclear physicists to realize that when base-loaded nuclear units are operated for long periods of time, near their technical potential, costs will fall and relative performance improves. Statistics for 1994 compiled by the Institute of Nuclear Operations (INPO) and the World Association of Nuclear Operators (WANO) showed the industry has steadily improved in most of the 10 industry-recognized categories. In 1994, Unit Capability Factor (the percentage of maximum energy generation a plant can supply to the grid) reached just under 82%, beating the 1995 goal and proving just how far the industry has come (62.7% in 1980) when improving plant operations.

  15. Time-Gated Optical Projection Tomography Allows Visualization of Adult Zebrafish Internal Structures

    Science.gov (United States)

    Foglia, Efrem Alessandro; Pistocchi, Anna; D'Andrea, Cosimo; Valentini, Gianluca; Cubeddu, Rinaldo; De Silvestri, Sandro; Cerullo, Giulio; Cotelli, Franco

    2012-01-01

    Optical imaging through biological samples is compromised by tissue scattering and currently various approaches aim to overcome this limitation. In this paper we demonstrate that an all optical technique, based on non-linear upconversion of infrared ultrashort laser pulses and on multiple view acquisition, allows the reduction of scattering effects in tomographic imaging. This technique, namely Time-Gated Optical Projection Tomography (TGOPT), is used to reconstruct three dimensionally the internal structure of adult zebrafish without staining or clearing agents. This method extends the use of Optical Projection Tomography to optically diffusive samples yielding reconstructions with reduced artifacts, increased contrast and improved resolution with respect to those obtained with non-gated techniques. The paper shows that TGOPT is particularly suited for imaging the skeletal system and nervous structures of adult zebrafish. PMID:23185643

  16. Benchmark Report on Key Outage Attributes: An Analysis of Outage Improvement Opportunities and Priorities

    Energy Technology Data Exchange (ETDEWEB)

    Germain, Shawn St. [Idaho National Laboratory (INL), Idaho Falls, ID (United States); Farris, Ronald [Idaho National Laboratory (INL), Idaho Falls, ID (United States)

    2014-09-01

    Advanced Outage Control Center (AOCC), is a multi-year pilot project targeted at Nuclear Power Plant (NPP) outage improvement. The purpose of this pilot project is to improve management of NPP outages through the development of an AOCC that is specifically designed to maximize the usefulness of communication and collaboration technologies for outage coordination and problem resolution activities. This report documents the results of a benchmarking effort to evaluate the transferability of technologies demonstrated at Idaho National Laboratory and the primary pilot project partner, Palo Verde Nuclear Generating Station. The initial assumption for this pilot project was that NPPs generally do not take advantage of advanced technology to support outage management activities. Several researchers involved in this pilot project have commercial NPP experience and believed that very little technology has been applied towards outage communication and collaboration. To verify that the technology options researched and demonstrated through this pilot project would in fact have broad application for the US commercial nuclear fleet, and to look for additional outage management best practices, LWRS program researchers visited several additional nuclear facilities.

  17. Continuous online monitoring of ionic dialysance allows modification of delivered hemodialysis treatment time.

    Science.gov (United States)

    Chesterton, Lindsay J; Priestman, William S; Lambie, Stewart H; Fielding, Catherine A; Taal, Maarten W; Fluck, Richard J; McIntyre, Christopher W

    2006-10-01

    Considerable intrinsic intrapatient variability influences the actual delivery of Kt/V. The aim of this study is to examine the feasibility of using continuous online assessment of ionic dialysance measurements (Kt/V(ID)) to allow dialysis sessions to be altered on an individual basis. Ten well-established chronic hemodialysis (HD) patients without significant residual renal function were studied (mean age 65+/-4.3 [38-81] years, mean length of time on dialysis 66+/-18 [14-189] months). These patients had all been receiving thrice-weekly 4-hr dialysis using Integra dialysis monitors. Dialysis monitors were equipped with Diascan modules permitting measurement of Kt/V(ID). Predicted treatment time required to achieve a Kt/V(ID) > or = 1.1 (equivalent to a urea-based method of 1.2) was calculated from the delivered Kt/V(ID) at 60 and 120 min. Treatment time was reprogrammed at 2 hr (ensuring all planned ultrafiltration would be accommodated into the new modified session duration). Owing to practical issues, and to avoid excessively short dialysis times, these changes were censored at no more than+/-10% of the usual 240-min treatment time (210-265 min). Data were collected from a total of 50 dialysis sessions. Almost all sessions (47/50) required modification of the standard treatment time: 13/50 sessions were lengthened and 34/50 shortened (mean length of session 232.2+/-2.5 [210-265] min). A Kt/V(ID) of > or = 1.1 was achieved in 39/50 sessions. The difference in mean urea-based Kt/V poststudy (1.3+/-0.05 [1.1-1.6]) and mean achieved Kt/V(ID) (1.16+/-0.02 [0.7-1.37]) was significant (p = 0.002). The use of individualized variable dialysis treatment time using online ionic dialysance measurements of Kt/V(ID) appears both practicable and effective at ensuring consistently delivered adequate dialysis.

  18. Guidelines for Implementation of an Advanced Outage Control Center to Improve Outage Coordination, Problem Resolution, and Outage Risk Management

    Energy Technology Data Exchange (ETDEWEB)

    St. Germain, Shawn W. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Farris, Ronald K. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Whaley, April M. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Medema, Heather D. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Gertman, David I. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2014-09-01

    This research effort is a part of the Light-Water Reactor Sustainability (LWRS) Program, which is a research and development (R&D) program sponsored by Department of Energy (DOE) and performed in close collaboration with industry R&D programs that provide the technical foundations for licensing and managing the long-term, safe, and economical operation of current nuclear power plants. The LWRS program serves to help the U.S. nuclear industry adopt new technologies and engineering solutions that facilitate the continued safe operation of the plants and extension of the current operating licenses. The purpose of this research is to improve management of nuclear power plant (NPP) outages through the development of an advanced outage control center (AOCC) that is specifically designed to maximize the usefulness of communication and collaboration technologies for outage coordination and problem resolution activities. This technical report for industry implementation outlines methods and considerations for the establishment of an AOCC. This report provides a process for implementation of a change management plan, evaluation of current outage processes, the selection of technology, and guidance for the implementation of the selected technology. Methods are presented for both adoption of technologies within an existing OCC and for a complete OCC replacement, including human factors considerations for OCC design and setup.

  19. Terahertz time domain spectroscopy allows contactless monitoring of grapevine water status

    Directory of Open Access Journals (Sweden)

    Luis Gonzaga Santesteban

    2015-06-01

    Full Text Available Agriculture is the sector with the greatest water consumption, since food production is frequently based on crop irrigation. Proper irrigation management requires reliable information on plant water status, but all the plant-based methods to determine it suffer from several inconveniences, mainly caused by the necessity of destructive sampling or of alteration of the plant organ due to contact installation. The aim of this work is to test if THz time domain reflectance measurements made on the grapevine trunk allows contactless monitoring of plant status. The experiments were performed on a potted 14-years old plant, using a general purpose THz emitter receiver head.Trunk THz time-domain reflection signal proved to be very sensitive to changes in plant water availability, as its pattern follows the trend of soil water content and trunk growth variations. Therefore, it could be used to contactless monitor plant water status. Apart from that, THz reflection signal was observed to respond to light conditions which, according to a specifically designed girdling experiment, was caused by changes in the phloem. This latter results opens a promising field of research for contactless monitoring of phloem activity.

  20. Cell outage compensation in LTE networks: Algorithms and performance assessment

    NARCIS (Netherlands)

    Amirijoo, M.; Jorguseski, L.; Litjens, R.; Schmelz, L.C.

    2011-01-01

    Cell outage compensation is a self-healing function and as such part of the Self-Organising Networks concept for mobile wireless networks. It aims at mitigating the degradation of coverage, capacity and service quality caused by a cell or site level outage. Upon detection of such an outage, cell out

  1. Sample Results from MCU Solids Outage

    Energy Technology Data Exchange (ETDEWEB)

    Peters, T.; Washington, A.; Oji, L.; Coleman, C.; Poirier, M.

    2014-09-22

    Savannah River National Laboratory (SRNL) has received several solid and liquid samples from MCU in an effort to understand and recover from the system outage starting on April 6, 2014. SRNL concludes that the presence of solids in the Salt Solution Feed Tank (SSFT) is the likely root cause for the outage, based upon the following discoveries: A solids sample from the extraction contactor #1 proved to be mostly sodium oxalate; A solids sample from the scrub contactor#1 proved to be mostly sodium oxalate; A solids sample from the Salt Solution Feed Tank (SSFT) proved to be mostly sodium oxalate; An archived sample from Tank 49H taken last year was shown to contain a fine precipitate of sodium oxalate; A solids sample from ; A liquid sample from the SSFT was shown to have elevated levels of oxalate anion compared to the expected concentration in the feed. Visual inspection of the SSFT indicated the presence of precipitated or transferred solids, which were likely also in the Salt Solution Receipt Tank (SSRT). The presence of the solids coupled with agitation performed to maintain feed temperature resulted in oxalate solids migration through the MCU system and caused hydraulic issues that resulted in unplanned phase carryover from the extraction into the scrub, and ultimately the strip contactors. Not only did this carryover result in the Strip Effluent (SE) being pushed out of waste acceptance specification, but it resulted in the deposition of solids into several of the contactors. At the same time, extensive deposits of aluminosilicates were found in the drain tube in the extraction contactor #1. However it is not known at this time how the aluminosilicate solids are related to the oxalate solids. The solids were successfully cleaned out of the MCU system. However, future consideration must be given to the exclusion of oxalate solids into the MCU system. There were 53 recommendations for improving operations recently identified. Some additional considerations or

  2. OTRA-THS MAC to reduce Power Outage Data Collection Latency in a smart meter network

    Energy Technology Data Exchange (ETDEWEB)

    Garlapati, Shravan K [ORNL; Kuruganti, Phani Teja [ORNL; Buehrer, Richard M [ORNL; Reed, Jeffrey H [ORNL

    2014-01-01

    The deployment of advanced metering infrastructure by the electric utilities poses unique communication challenges, particularly as the number of meters per aggregator increases. During a power outage, a smart meter tries to report it instantaneously to the electric utility. In a densely populated residential/industrial locality, it is possible that a large number of smart meters simultaneously try to get access to the communication network to report the power outage. If the number of smart meters is very high of the order of tens of thousands (metropolitan areas), the power outage data flooding can lead to Random Access CHannel (RACH) congestion. Several utilities are considering the use of cellular network for smart meter communications. In 3G/4G cellular networks, RACH congestion not only leads to collisions, retransmissions and increased RACH delays, but also has the potential to disrupt the dedicated traffic flow by increasing the interference levels (3G CDMA). In order to overcome this problem, in this paper we propose a Time Hierarchical Scheme (THS) that reduces the intensity of power outage data flooding and power outage reporting delay by 6/7th, and 17/18th when compared to their respective values without THS. Also, we propose an Optimum Transmission Rate Adaptive (OTRA) MAC to optimize the latency in power outage data collection. The analysis and simulation results presented in this paper show that both the OTRA and THS features of the proposed MAC results in a Power Outage Data Collection Latency (PODCL) that is 1/10th of the 4G LTE PODCL.

  3. Power outages, power externalities, and baby booms.

    Science.gov (United States)

    Burlando, Alfredo

    2014-08-01

    Determining whether power outages have significant fertility effects is an important policy question in developing countries, where blackouts are common and modern forms of family planning are scarce. Using birth records from Zanzibar, this study shows that a month-long blackout in 2008 caused a significant increase in the number of births 8 to 10 months later. The increase was similar across villages that had electricity, regardless of the level of electrification; villages with no electricity connections saw no changes in birth numbers. The large fertility increase in communities with very low levels of electricity suggests that the outage affected the fertility of households not connected to the grid through some spillover effect. Whether the baby boom is likely to translate to a permanent increase in the population remains unclear, but this article highlights an important hidden consequence of power instability in developing countries. It also suggests that electricity imposes significant externality effects on rural populations that have little exposure to it.

  4. Distributed Power-Line Outage Detection Based on Wide Area Measurement System

    Directory of Open Access Journals (Sweden)

    Liang Zhao

    2014-07-01

    Full Text Available In modern power grids, the fast and reliable detection of power-line outages is an important functionality, which prevents cascading failures and facilitates an accurate state estimation to monitor the real-time conditions of the grids. However, most of the existing approaches for outage detection suffer from two drawbacks, namely: (i high computational complexity; and (ii relying on a centralized means of implementation. The high computational complexity limits the practical usage of outage detection only for the case of single-line or double-line outages. Meanwhile, the centralized means of implementation raises security and privacy issues. Considering these drawbacks, the present paper proposes a distributed framework, which carries out in-network information processing and only shares estimates on boundaries with the neighboring control areas. This novel framework relies on a convex-relaxed formulation of the line outage detection problem and leverages the alternating direction method of multipliers (ADMM for its distributed solution. The proposed framework invokes a low computational complexity, requiring only linear and simple matrix-vector operations. We also extend this framework to incorporate the sparse property of the measurement matrix and employ the LSQRalgorithm to enable a warm start, which further accelerates the algorithm. Analysis and simulation tests validate the correctness and effectiveness of the proposed approaches.

  5. Distributed power-line outage detection based on wide area measurement system.

    Science.gov (United States)

    Zhao, Liang; Song, Wen-Zhan

    2014-07-21

    In modern power grids, the fast and reliable detection of power-line outages is an important functionality, which prevents cascading failures and facilitates an accurate state estimation to monitor the real-time conditions of the grids. However, most of the existing approaches for outage detection suffer from two drawbacks, namely: (i) high computational complexity; and (ii) relying on a centralized means of implementation. The high computational complexity limits the practical usage of outage detection only for the case of single-line or double-line outages. Meanwhile, the centralized means of implementation raises security and privacy issues. Considering these drawbacks, the present paper proposes a distributed framework, which carries out in-network information processing and only shares estimates on boundaries with the neighboring control areas. This novel framework relies on a convex-relaxed formulation of the line outage detection problem and leverages the alternating direction method of multipliers (ADMM) for its distributed solution. The proposed framework invokes a low computational complexity, requiring only linear and simple matrix-vector operations. We also extend this framework to incorporate the sparse property of the measurement matrix and employ the LSQRalgorithm to enable a warm start, which further accelerates the algorithm. Analysis and simulation tests validate the correctness and effectiveness of the proposed approaches.

  6. Advanced Outage and Control Center: Strategies for Nuclear Plant Outage Work Status Capabilities

    Energy Technology Data Exchange (ETDEWEB)

    Gregory Weatherby

    2012-05-01

    The research effort is a part of the Light Water Reactor Sustainability (LWRS) Program. LWRS is a research and development program sponsored by the Department of Energy, performed in close collaboration with industry to provide the technical foundations for licensing and managing the long-term, safe and economical operation of current nuclear power plants. The LWRS Program serves to help the US nuclear industry adopt new technologies and engineering solutions that facilitate the continued safe operation of the plants and extension of the current operating licenses. The Outage Control Center (OCC) Pilot Project was directed at carrying out the applied research for development and pilot of technology designed to enhance safe outage and maintenance operations, improve human performance and reliability, increase overall operational efficiency, and improve plant status control. Plant outage management is a high priority concern for the nuclear industry from cost and safety perspectives. Unfortunately, many of the underlying technologies supporting outage control are the same as those used in the 1980’s. They depend heavily upon large teams of staff, multiple work and coordination locations, and manual administrative actions that require large amounts of paper. Previous work in human reliability analysis suggests that many repetitive tasks, including paper work tasks, may have a failure rate of 1.0E-3 or higher (Gertman, 1996). With between 10,000 and 45,000 subtasks being performed during an outage (Gomes, 1996), the opportunity for human error of some consequence is a realistic concern. Although a number of factors exist that can make these errors recoverable, reducing and effectively coordinating the sheer number of tasks to be performed, particularly those that are error prone, has the potential to enhance outage efficiency and safety. Additionally, outage management requires precise coordination of work groups that do not always share similar objectives. Outage

  7. Transmission network expansion planning under deliberate outages

    Energy Technology Data Exchange (ETDEWEB)

    Alguacil, Natalia; Carrion, Miguel; Arroyo, Jose Manuel [E.T.S. de Ingenieros Industriales, Universidad de Castilla - La Mancha, Campus Universitario s/n, 13071 Ciudad Real (Spain)

    2009-10-15

    The reasons why the transmission network is a potentially attractive target for deliberate outages are twofold: (i) its crucial importance as a critical infrastructure for the society welfare, and (ii) its high level of vulnerability due to the current operation close to its static and dynamic limits. This new context where destructive agents come into play has been recognized by several agencies in Europe and North America, and various initiatives have been launched worldwide in order to assess and mitigate the vulnerability of transmission. Within this framework, this paper proposes the reinforcement and expansion of the transmission network as a way of mitigating the impact of increasingly plausible deliberate outages. The network planner selects the new lines to be built accounting not only for economic issues, as traditionally done, but also for the vulnerability of the transmission network against a set of credible intentional outages. The resulting vulnerability- and economic-constrained transmission expansion planning problem is formulated as a mixed-integer linear program. A number of case studies numerically illustrate the tradeoff between economic- and vulnerability-related issues and its impact on the expansion plans. In addition, we compare the results with those achieved by a traditional expansion planning model based on cost minimization. (author)

  8. Design Concepts for an Outage Control Center Information Dashboard

    Energy Technology Data Exchange (ETDEWEB)

    Hugo, Jacques Victor [Idaho National Lab. (INL), Idaho Falls, ID (United States); St Germain, Shawn Walter [Idaho National Lab. (INL), Idaho Falls, ID (United States); Thompson, Cheradan Jo [Idaho National Lab. (INL), Idaho Falls, ID (United States); Whitesides, McKenzie Jo [Idaho National Lab. (INL), Idaho Falls, ID (United States); Farris, Ronald Keith [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-12-01

    The nuclear industry, and the business world in general, is facing a rapidly increasing amount of data to be dealt with on a daily basis. In the last two decades, the steady improvement of data storage devices and means to create and collect data along the way influenced the manner in which we deal with information. Most data is still stored without filtering and refinement for later use. Many functions at a nuclear power plant generate vast amounts of data, with scheduled and unscheduled outages being a prime example of a source of some of the most complex data sets at the plant. To make matters worse, modern information and communications technology is making it possible to collect and store data faster than our ability to use it for making decisions. However, in most applications, especially outages, raw data has no value in itself; instead, managers, engineers and other specialists want to extract the information contained in it. The complexity and sheer volume of data could lead to information overload, resulting in getting lost in data that may be irrelevant to the task at hand, processed in an inappropriate way, or presented in an ineffective way. To prevent information overload, many data sources are ignored so production opportunities are lost because utilities lack the ability to deal with the enormous data volumes properly. Decision-makers are often confronted with large amounts of disparate, conflicting and dynamic information, which are available from multiple heterogeneous sources. Information and communication technologies alone will not solve this problem. Utilities need effective methods to exploit and use the hidden opportunities and knowledge residing in unexplored data resources. Superior performance before, during and after outages depends upon the right information being available at the right time to the right people. Acquisition of raw data is the easy part; instead, it is the ability to use advanced analytical, data processing and data

  9. A guideline for optimizing outage management of Eskom's transmission network / Michelle de Haan

    OpenAIRE

    de Haan, Michelle

    2012-01-01

    A streamlined process is needed to optimize the outage management of the Eskom transmission power system, as well as a ranking system in order to determine the best window of opportunity for an outage to occur thus positively impacting on Eskom‘s asset management. The outage data captured between 2007 and 2011 was analysed for all cancelled, turned down and completed outages. This data indicated that there were 19 902 completed outages, 5 312 cancelled outages and 1 889 turned down outages...

  10. The detection, prevention and mitigation of cascading outages in the power system

    Science.gov (United States)

    Song, Hongbiao

    This dissertation studies the causes and mechanism of power system cascading outages and develops new methods and new tools to help detect, prevent and mitigate the outages. Three effective solutions: a steady state control scheme, a transient stability control scheme, and an interactive system-wide and local scheme have been proposed using those new methods and tools. A steady state control scheme can help detect and prevent the possible cascading outage at its initial slow steady state progress stage. It uses new methods and new tools to solve the line overload, congestion or bus high/low voltage problems. New methods, such as vulnerability index (VI), margin index (MI), network contribution factor (NCF), topology processing and selected minimum load shedding (SMLS), and new tools, such as transmission network control based on a network contribution factor (NCF) method, generator control based on a generator distribution factor (GDF) method, and load control based on a load distribution factor (LDF) method have been proposed and developed. A transient stability control scheme can help prevent and mitigate the possible cascading outage at its transient progress stage if there is enough time to take action. It uses one Lyapunov direct method, potential energy boundary surface (PEBS) method, and sensitivity analysis of transient energy margin for fast stabilizing control. The results are verified by the accurate time-domain transient stability analysis method. The interactive scheme takes advantage of accurate system-wide and local information and analysis results, uses some techniques from both steady state control and transient stability control, works at both the system-wide level and local substation level, monitors the system all the time, and takes actions when needed to help detect, prevent and mitigate the possible cascading outage. Comprehensive simulation studies have been implemented using the IEEE 14-bus, 24-bus, 39-bus and 118-bus systems and promising

  11. Cost Benefit Analysis of the Power Storage System Considering Outage Cost in the Deregulated Power Market

    Science.gov (United States)

    Tsuru, Hirokazu; Fujii, Yasumasa

    In this paper, the authors propose the mathematical model which derives the optimal operation strategies of an on-site power storage system through the use of stochastic dynamic programming technique. The model takes account of the variations and uncertainties of electricity market prices as well as the outage costs of power grid failures. The market price fluctuation is modeled with stochastic differential equation. The stochastic state transitions between normal and failed systems are modeled with exponential density functions. The derived optimal operation indicates that the economic value of the storage system may be increased substantially, if the avoided outage costs are explicitly taken into account. The results of the sensitivity analysis indicate that the most influential parameters are the magnitude of outage cost and the mean time to failure of power grid.

  12. Outage Performance of Flexible OFDM Schemes in Packet-Switched Transmissions

    Directory of Open Access Journals (Sweden)

    Romain Couillet

    2009-01-01

    Full Text Available α-OFDM, a generalization of the OFDM modulation, is proposed. This new modulation enhances the outage capacity performance of bursty communications. The α-OFDM scheme is easily implementable as it only requires an additional time symbol rotation after the IDFT stage and a subsequent phase rotation of the cyclic prefix. The physical effect of the induced rotation is to slide the DFT window over the frequency spectrum. When successively used with different angles α at the symbol rate, α-OFDM provides frequency diversity in block fading channels. Interestingly, simulation results show a substantial gain in terms of outage capacity and outage BER in comparison with classical OFDM modulation schemes. The framework is extended to multiantenna and multicellular OFDM-based standards. Practical simulations, in the context of 3GPP-LTE, called hereafter α-LTE, sustain our theoretical claims.

  13. The effect of power outages and cheap talk on willingness to pay to reduce outages

    OpenAIRE

    Carlsson, Fredrik; Martinsson, Peter; AKAY Alpaslan

    2009-01-01

    Using an open-ended contingent valuation survey, we analyze how (i) experience of a power outage due to one of the worst storms ever to hit Sweden and (ii) a cheap talk script affect respondents' WTP to avoid power outages. Experience significantly increases and a cheap talk script decreases the proportion of respondents with zero WTP. There is no significant effect in either case on stated WTP conditional on a positive WTP. The paper concludes with a discussion on the use of valuation studie...

  14. Scales of Time Where the Quantum Discord Allows an Efficient Execution of the DQC1 Algorithm

    Directory of Open Access Journals (Sweden)

    M. Ávila

    2014-01-01

    Full Text Available The power of one qubit deterministic quantum processor (DQC1 (Knill and Laflamme (1998 generates a nonclassical correlation known as quantum discord. The DQC1 algorithm executes in an efficient way with a characteristic time given by τ=Tr[Un]/2n, where Un is an n qubit unitary gate. For pure states, quantum discord means entanglement while for mixed states such a quantity is more than entanglement. Quantum discord can be thought of as the mutual information between two systems. Within the quantum discord approach the role of time in an efficient evaluation of τ is discussed. It is found that the smaller the value of t/T is, where t is the time of execution of the DQC1 algorithm and T is the scale of time where the nonclassical correlations prevail, the more efficient the calculation of τ is. A Mösbauer nucleus might be a good processor of the DQC1 algorithm while a nuclear spin chain would not be efficient for the calculation of τ.

  15. MIMO ARQ with Multi-bit Feedback: Outage Analysis

    CERN Document Server

    Nguyen, Khoa D; Fabregas, Albert Guillen i; Letzepis, Nick

    2010-01-01

    We study the asymptotic outage performance of incremental redundancy automatic repeat request (INR-ARQ) transmission over the multiple-input multiple-output (MIMO) block-fading channels with discrete input constellations. We first show that transmission with random codes using a discrete signal constellation across all transmit antennas achieves the optimal outage diversity given by the Singleton bound. We then analyze the optimal SNR-exponent and outage diversity of INR-ARQ transmission over the MIMO block-fading channel. We show that a significant gain in outage diversity is obtained by providing more than one bit feedback at each ARQ round. Thus, the outage performance of INR-ARQ transmission can be remarkably improved with minimal additional overhead. A suboptimal feedback and power adaptation rule, which achieves the optimal outage diversity, is proposed for MIMO INR-ARQ, demonstrating the benefits provided by multi-bit feedback.

  16. Time Gating of Chloroplast Autofluorescence Allows Clearer Fluorescence Imaging In Planta.

    Directory of Open Access Journals (Sweden)

    Yutaka Kodama

    Full Text Available Chloroplast, an organelle facilitating photosynthesis, exhibits strong autofluorescence, which is an undesired background signal that restricts imaging experiments with exogenous fluorophore in plants. In this study, the autofluorescence was characterized in planta under confocal laser microscopy, and it was found that the time-gated imaging technique completely eliminates the autofluorescence. As a demonstration of the technique, a clearer signal of fluorescent protein-tagged phototropin, a blue-light photoreceptor localized at the chloroplast periphery, was visualized in planta.

  17. Cherenkov Video Imaging Allows for the First Visualization of Radiation Therapy in Real Time

    Energy Technology Data Exchange (ETDEWEB)

    Jarvis, Lesley A., E-mail: Lesley.a.jarvis@hitchcock.org [Department of Medicine, Geisel School of Medicine at Dartmouth College, Hanover, New Hampshire (United States); Norris Cotton Cancer Center at the Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire (United States); Zhang, Rongxiao [Department of Physics and Astronomy, Dartmouth College, Hanover, New Hampshire (United States); Gladstone, David J. [Department of Medicine, Geisel School of Medicine at Dartmouth College, Hanover, New Hampshire (United States); Norris Cotton Cancer Center at the Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire (United States); Jiang, Shudong [Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire (United States); Hitchcock, Whitney [Geisel School of Medicine at Dartmouth College, Hanover, New Hampshire (United States); Friedman, Oscar D.; Glaser, Adam K.; Jermyn, Michael [Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire (United States); Pogue, Brian W. [Department of Physics and Astronomy, Dartmouth College, Hanover, New Hampshire (United States); Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire (United States)

    2014-07-01

    Purpose: To determine whether Cherenkov light imaging can visualize radiation therapy in real time during breast radiation therapy. Methods and Materials: An intensified charge-coupled device (CCD) camera was synchronized to the 3.25-μs radiation pulses of the clinical linear accelerator with the intensifier set × 100. Cherenkov images were acquired continuously (2.8 frames/s) during fractionated whole breast irradiation with each frame an accumulation of 100 radiation pulses (approximately 5 monitor units). Results: The first patient images ever created are used to illustrate that Cherenkov emission can be visualized as a video during conditions typical for breast radiation therapy, even with complex treatment plans, mixed energies, and modulated treatment fields. Images were generated correlating to the superficial dose received by the patient and potentially the location of the resulting skin reactions. Major blood vessels are visible in the image, providing the potential to use these as biological landmarks for improved geometric accuracy. The potential for this system to detect radiation therapy misadministrations, which can result from hardware malfunction or patient positioning setup errors during individual fractions, is shown. Conclusions: Cherenkoscopy is a unique method for visualizing surface dose resulting in real-time quality control. We propose that this system could detect radiation therapy errors in everyday clinical practice at a time when these errors can be corrected to result in improved safety and quality of radiation therapy.

  18. Time Segmentation Approach Allowing QoS and Energy Saving for Wireless Sensor Networks

    CERN Document Server

    Chalhoub, Gerard; Misson, Michel

    2010-01-01

    Wireless sensor networks are conceived to monitor a certain application or physical phenomena and are supposed to function for several years without any human intervention for maintenance. Thus, the main issue in sensor networks is often to extend the lifetime of the network by reducing energy consumption. On the other hand, some applications have high priority traffic that needs to be transferred within a bounded end-to-end delay while maintaining an energy efficient behavior. We propose MaCARI, a time segmentation protocol that saves energy, improves the overall performance of the network and enables quality of service in terms of guaranteed access to the medium and end-to-end delays. This time segmentation is achieved by synchronizing the activity of nodes using a tree-based beacon propagation and allocating activity periods for each cluster of nodes. The tree-based topology is inspired from the cluster-tree proposed by the ZigBee standard. The efficiency of our protocol is proven analytically, by simulati...

  19. ESTIMATION MODEL OF RESIDUAL LIFE-TIME OF LOCOMOTIVE FRAME BOGIE WITH ALLOWANCE FOR CREEP

    Directory of Open Access Journals (Sweden)

    V. R. Skalskyi

    2014-12-01

    Full Text Available Purpose. The problem of determining the residual life of frame bogie elements of locomotives is a great importance for predicting their work safely and avoidance potential failures on the track. This especially concern cases when such elements have creep-fatigue cracks which grow under action of cyclic loading with excerpts T1 in the cycle and reach their critical size. Here the question of the propagation of such defects (cracks arises, their kinetics and about the period of subcritical cracks growth. The aim is to develop a calculation model for determination the period of subcritical creep-fatigue cracks growth in the bogies frames of electric locomotive. The model takes into account the basic parameters of load, geometry of the construction element and cracks. Methodology. The calculation model for determination the period of subcritical creep-fatigue cracks growth in structural elements of frame under conditions of variable load time has been formulated. It is based on the first law of thermodynamics concerning to mechanics of solids slow fracture at low temperature creep and variable loadings. It is assumed that the period of unsteady creep dominates here (the first section of the creep curve. Low-temperature creep is creep of materials at temperatures T0 < 0,5Tmp, where Tmp − the melting point of the material. Findings. The analytical formula for the determination of the stress intensity factor of truck bolster with technological hole has been obtained. It is shown that by experimentally established constants of the material using the proposed analytical relations can easily determine residual resource of the bogie frame elements. Originality. The new mathematical model for describing the kinetics of creep-fatigue cracks growth in the frames bogies of electric locomotive under variable in time loadings with various time excerpts and on this base the period determination of subcritical crack growth has been proposed. Practical value

  20. Outage Key Safety Functions Configuration risk assessment for a three loops Westinghouse PWR

    Energy Technology Data Exchange (ETDEWEB)

    Cid, M.M.; Dies, J., E-mail: javier.Dies@Upc.Edu; Tapia, C., E-mail: carlos.Tapia@Upc.Edu; Diaz, P., E-mail: pedro.diaz.bayona@upc.edu

    2015-09-15

    Highlights: • The paper evaluates the use of PSA on the Outage configuration risk management. • A method is proposed based on Risk Criteria to evaluate the OKSFs’ Configurations. • The methodology allows to identify which of the OKSFs can be analyzed using PSA. • The method has been applied to a Pilot real case. The OKSFs procedure is evaluated. - Abstract: The methodology developed provides guidance on the use of Probabilistic Safety Assessment (PSA) for the risk-informed evaluation of Guides which ensure the compliment of Outage Key Safety Functions (OKSFs) in Nuclear Power Plants. The methodology has been applied to the 3rd and 13th Plant Operational States (POSs) as a pilot experience. These POSs are within the Operating Mode 4 (Hot Shutdown) of a three loops Westinghouse Pressurized Water Reactor. The addressed Guide requires the operability of just one charge pump as boric acid supply source. PSA gives a Core Damage Frequency increase (ΔCDF) of 1.19 × 10{sup −6} year{sup −1} for the unavailability of the charge pump in standby, consequently, the maximum exposure time (time for the Increase of Core Damage Probability of the configuration to reach 1.0E−06) for this situation is T = 53.6 h. Given an average time for the POSs of 40 h, it is concluded that the charge pumps requirement is correct. However, it could be improved with the inclusion of an additional inventory replacement function. This would limit the effect on risk of the charge pump unavailability. Furthermore, the need for the external electrical sources to be available during Mode 4 is ratified. The procedure requires the operability of both supply sources during the POSs. The unavailability of one of supply sources them involves a ΔCDF equal to 1.64 × 10{sup −5} year{sup −1} and a maximum exposure time of T = 3.89 h. This requirement is considered appropriate from the risk-informed regulation point of view.

  1. Outage Analysis of Dual-hop Cognitive Networks with Relay Selection over Nakagami-m Fading Environment

    Science.gov (United States)

    Zhang, Zongsheng; Pi, Xurong

    2014-09-01

    In this paper, we investigate the outage performance of decode-and-forward cognitive relay networks for Nakagami-m fading channels, with considering both best relay selection and interference constraints. Focusing on the relay selection and making use of the underlay cognitive approach, an exact closed-form outage probability expression is derived in an independent, non-identical distributed Nakagami-m environment. The closed-form outage probability provides an efficient means to evaluate the effects of the maximum allowable interference power, number of cognitive relays, and channel conditions between the primary user and cognitive users. Finally, we present numerical results to validate the theory analysis. Moreover, from the simulation results, we obtain that the system can obtain the full diversity.

  2. Outage performance of cognitive radio systems with Improper Gaussian signaling

    KAUST Repository

    Amin, Osama

    2015-06-14

    Improper Gaussian signaling has proved its ability to improve the achievable rate of the systems that suffer from interference compared with proper Gaussian signaling. In this paper, we first study impact of improper Gaussian signaling on the performance of the cognitive radio system by analyzing the outage probability of both the primary user (PU) and the secondary user (SU). We derive exact expression of the SU outage probability and upper and lower bounds for the PU outage probability. Then, we design the SU signal by adjusting its transmitted power and the circularity coefficient to minimize the SU outage probability while maintaining a certain PU quality-of-service. Finally, we evaluate the proposed bounds and adaptive algorithms by numerical results.

  3. Lassoing Line Outages in the Smart Power Grid

    OpenAIRE

    Zhu, Hao; Giannakis, Georgios B.

    2011-01-01

    Fast and accurate unveiling of power line outages is of paramount importance not only for preventing faults that may lead to blackouts, but also for routine monitoring and control tasks of the smart grid, including state estimation and optimal power flow. Existing approaches are either challenged by the \\emph{combinatorial complexity} issues involved, and are thus limited to identifying single- and double-line outages; or, they invoke less pragmatic assumptions such as \\emph{conditionally ind...

  4. Modelling lightning caused transmission line outages in Alberta

    Energy Technology Data Exchange (ETDEWEB)

    Wu, M.; Shen, S.S.P. [Alberta Univ., Edmonton, AB (Canada). Dept. of Mathematical and Statistical Sciences; Koval, D.O. [Alberta Univ., Edmonton, AB (Canada). Dept. of Electrical Engineering

    2005-07-01

    The characteristics of lightning and the relationship between lightning and transmission line outages is not fully understood by utility planners. This study used 20 year data sets of lightning events to investigate the spatial and temporal patterns of lightning in Alberta. Studies of geographical and temporal characteristics of lightning caused transmission line outages for several voltage level transmission lines were also examined. A lasso regression variable selection procedure and Cp criterion were used to model the duration of the lightning-caused transmission line outages as a function of weather and lightning patterns. The province was divided into 110 by 110 grids, and lightning variables were calculated for each cell. All the lightning variables for each cell were then averaged based on their areas. The overall cloud-ground lightning flashes 20-year mean frequency and the physical locations of power transmission lines were then plotted. Estimated probability density functions of the duration of lightning caused transmission line outages were classified by their voltage levels. The study showed that the characteristics of the lightning caused outages were different for different voltage levels of the transmission lines. Results suggested that the findings will have a significant impact on the accuracy of reliability methodologies that use the average duration of transmission line outages in their calculations. It was concluded that the new methodology can be applied to any transmission line system operating in a unique geographical environmental area. 11 refs., 3 tabs., 5 figs.

  5. Analysis of the Dependence of Power Outages on Lightning Events within the Ijebu Province, Nigeria

    OpenAIRE

    J.O. Adepitan; E.O. Oladiran

    2012-01-01

    The study aimed at developing a model for lightning-induced outages in Nigeria from results obtained on determining the proportion and rate of lightning-induced outages out of the total power outages experienced in Ijebu province of Nigeria. Power outage records for Ijebu province, comprising Ijebu-Ode and Sagamu areas, Ogun state, Nigeria for the years 2002-2006 were collected from Power Holding Company of Nigeria (PHCN). Unintentional stochastic outages were separated from those due to deli...

  6. Forecasting New Hampshire Power Outages through the Analysis of Weather Station Observations

    Science.gov (United States)

    Fessenden, Ross T.

    Eversource Energy, formerly Public Service of New Hampshire (PSNH), has worked closely with Plymouth State University (PSU) in the past, and present, to better predict weather-related power outage events and maximize the efficiency with which Eversource responds to them. This research paired weather data from thirteen stations throughout New Hampshire, Vermont, and Massachusetts with Eversource Trouble Report and Unsatisfactory Performance of Equipment Report (TRUPER) data in an effort to quantify weather situations that lead to power outages. The ultimate goal involved developing a predictive model that uses weather data to forecast the magnitude of power outages. The study focused on the Eversource Western/Central service territory and utilized data from 2006-2010. The first four years, 2006-2009, were analyzed using Classification and Regression Tree (CART) statistical analysis. The results of this CART analysis trained a predictive model, while the fifth year, 2010, served as the testing set for the predictive model. To conduct the statistical analysis, a database was created pairing TRUPER reports with the closest available hourly weather observations. The database included nine weather variables matched with three variables from the TRUPER data: 1) customers, 2) customer minutes, and 3) outage duration. While the entire Eversource service territory saw 91,286 TRUPERs from 2006-2010, the Western/Central service territory, the focus of this study, accounted for 29,430. Before conducting the CART analysis, correlations between single weather variables and TRUPER data were calculated and, in general, proved xi weak. In addition to analyzing the complete four-year training data set, many portions/variations of the data set were analyzed. The analyses included a yearly analysis, time lag analysis, cold/warm-season analysis, and a single-station analysis. Although individual years and smaller data sets showed moderately higher correlations between weather and outage

  7. Innovation on Energy Power Technology (15)Great Advances in Power System Stabilizing Technology triggered by the Wide-area Outage

    Science.gov (United States)

    Egawa, Masanao

    On July 23, 1987, a very hot day, the largest wide-area power outage occurred in Kanto-Area, Japan. The cause was a voltage collapse on the bulk power network of Tokyo Electric Power Company, due to the abnormal rate of demand rising following resume after lunch break. Aggressive studies on voltage collapse throughout industry and university have led to great advances in power system stability. This essay describes the detail record of the outage, the applied countermeasures, and the inside story when the multiple voltage solutions of power flow on actual power system were found out for the first time.

  8. Oscillation-Driven Spike-Timing Dependent Plasticity Allows Multiple Overlapping Pattern Recognition in Inhibitory Interneuron Networks.

    Science.gov (United States)

    Garrido, Jesús A; Luque, Niceto R; Tolu, Silvia; D'Angelo, Egidio

    2016-08-01

    The majority of operations carried out by the brain require learning complex signal patterns for future recognition, retrieval and reuse. Although learning is thought to depend on multiple forms of long-term synaptic plasticity, the way this latter contributes to pattern recognition is still poorly understood. Here, we have used a simple model of afferent excitatory neurons and interneurons with lateral inhibition, reproducing a network topology found in many brain areas from the cerebellum to cortical columns. When endowed with spike-timing dependent plasticity (STDP) at the excitatory input synapses and at the inhibitory interneuron-interneuron synapses, the interneurons rapidly learned complex input patterns. Interestingly, induction of plasticity required that the network be entrained into theta-frequency band oscillations, setting the internal phase-reference required to drive STDP. Inhibitory plasticity effectively distributed multiple patterns among available interneurons, thus allowing the simultaneous detection of multiple overlapping patterns. The addition of plasticity in intrinsic excitability made the system more robust allowing self-adjustment and rescaling in response to a broad range of input patterns. The combination of plasticity in lateral inhibitory connections and homeostatic mechanisms in the inhibitory interneurons optimized mutual information (MI) transfer. The storage of multiple complex patterns in plastic interneuron networks could be critical for the generation of sparse representations of information in excitatory neuron populations falling under their control.

  9. Prediction of power system frequency response after generator outages using neural nets

    Energy Technology Data Exchange (ETDEWEB)

    Djukanovic, M.B.; Popovic, D.P. (Electrotechnicki Inst. ' Nikola Tesla' , Belgrade (Yugoslavia)); Sobajic, D.J.; Pao, Y.-H. (Case Western Reserve Univ., Cleveland, OH (United States))

    1993-09-01

    A new methodology is presented for estimating the frequency behaviour of power systems necessary for an indication of under-frequency load shedding in steady-state security assessment. It is well known that large structural disturbances such as generator tripping or load outages can initiate cascading outages, system separation into islands, and even the complete breakup. The approach provides a fairly accurate method of estimating the system average frequency response without making simplifications or neglecting non-linearities and small time constants in the equations of generating units, voltage regulators and turbines. The efficiency of the new procedure is demonstrated using the New England power system model for a series of characteristic perturbations. The validity of the proposed approach is verified by comparison with the simulation of short-term dynamics including effects of control and automatic devices. (author)

  10. TOPOLOGY AND CASCADING LINE OUTAGES IN POWER GRIDS

    Institute of Scientific and Technical Information of China (English)

    David L. PEPYNE

    2007-01-01

    Motivated by the small world network research of Watts & Strogatz, this paper studies relationships between topology and cascading line outages in electric power grids. Cascading line outages are a type of cascading collapse that can occur in power grids when the transmission network is congested. It is characterized by a self-sustaining sequence of line outages followed by grid breakup, which generally leads to widespread blackout. The main findings of this work are twofold: On one hand, the work suggests that topologies with more disorder in their interconnection topology tend to be robust with respect to cascading line outages in the sense of being able to support greater generation and demand levels than more regularly interconnected topologies. On the other hand, the work suggests that topologies with more disorder tend to be more fragile in that should a cascade get started, they tend to break apart after fewer outages than more regularly interconnected topologies. Thus, as has been observed in other complex networks, there appears to be a tradeoff between robustness and fragility.These results were established using synthetically generated power grid topologies and verified using the IEEE 57 bus and 188 bus power grid test cases.

  11. 47 CFR 4.11 - Notification and initial and final communications outage reports that must be filed by...

    Science.gov (United States)

    2010-10-01

    ... Notification shall provide: The name of the reporting entity; the date and time of onset of the outage; a brief... FEDERAL COMMUNICATIONS COMMISSION GENERAL DISRUPTIONS TO COMMUNICATIONS Reporting Requirements for... and contact telephone number by which the Commission's technical staff may contact the...

  12. An Isotropic SPPP Mo del for Femto cells Networks with Outage Probability Constraints

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jun; TIAN Hui

    2015-01-01

    Femtocells have been considered as a cost-eff ective solution to unload traffic from already overbur-dened macrocell networks in 4G cellular networks. The severe interference in spectrum-sharing macro and femto networks may cause User-equipment (UE) to experience outage. We derive an utmost isotropic Spatial Poisson point process (SPPP) density for Femtocell access points (FAPs) under the UEs’ outage constraints. Based on the derived isotropic SPPP density, we propose a distributed transmit probability self-regulation scheme for an FAP to adapt its transmit probability per Transmission time in-terval (TTI). The scheme adjusts the homogeneous dis-tributed FAPs in practice deployment to the proposed isotropic one. Simulation results show that the derived den-sity can fulfill the outage probability constraints of UEs while accommodating the maximum femtocells. The self-regulation scheme can adapt the femtocell transmit prob-abilities to provide reliable downlink service, for even a large number of femtocells per cell site.

  13. Differential timing of antibody-mediated phagocytosis and cell-free killing of invasive African Salmonella allows immune evasion.

    Science.gov (United States)

    Siggins, Matthew K; O'Shaughnessy, Colette M; Pravin, John; Cunningham, Adam F; Henderson, Ian R; Drayson, Mark T; MacLennan, Calman A

    2014-04-01

    Nontyphoidal Salmonellae commonly cause fatal bacteraemia in African children lacking anti-Salmonella antibodies. These are facultative intracellular bacteria capable of cell-free and intracellular survival within macrophages. To better understand the relationship between extracellular and intracellular infection in blood and general mechanisms of Ab-related protection against Salmonella, we used human blood and sera to measure kinetics of Ab and complement deposition, serum-mediated bactericidal killing and phagocytosis of invasive African Salmonella enterica serovar Typhimurium D23580. Binding of antibodies peaked by 30 s, but C3 deposition lagged behind, peaking after 2-4 min. C5b-9 deposition was undetectable until between 2 and 6 min and peaked after 10 min, after which time an increase in serum-mediated killing occurred. In contrast, intracellular, opsonized Salmonellae were readily detectable within 5 min. By 10 min, around half of monocytes and most neutrophils contained bacteria. The same kinetics of serum-mediated killing and phagocytosis were observed with S. enterica Typhimurium laboratory strain SL1344, and the S. enterica Enteritidis African invasive isolate D24954 and laboratory strain PT4. The differential kinetics between cell-free killing and phagocytosis of invasive nontyphoidal Salmonella allows these bacteria to escape the blood and establish intracellular infection before they are killed by the membrane attack complex.

  14. CHILD ALLOWANCE

    CERN Multimedia

    Human Resources Division

    2001-01-01

    HR Division wishes to clarify to members of the personnel that the allowance for a dependent child continues to be paid during all training courses ('stages'), apprenticeships, 'contrats de qualification', sandwich courses or other courses of similar nature. Any payment received for these training courses, including apprenticeships, is however deducted from the amount reimbursable as school fees. HR Division would also like to draw the attention of members of the personnel to the fact that any contract of employment will lead to the suppression of the child allowance and of the right to reimbursement of school fees.

  15. Obtaining statistics of cascading line outages spreading in an electric transmission network from standard utility data

    CERN Document Server

    Dobson, Ian

    2015-01-01

    We show how to use standard transmission line outage historical data to obtain the network topology in such a way that cascades of line outages can be easily located on the network. Then we obtain statistics quantifying how cascading outages typically spread on the network. Processing real outage data is fundamental for understanding cascading and for evaluating the validity of the many different models and simulations that have been proposed for cascading in power networks.

  16. Threshold-based monitoring of cascading outages with PMU measurements of area angle

    OpenAIRE

    Darvishi, Atena; Dobson, Ian

    2014-01-01

    When power grids are heavily stressed with a bulk power transfer, it is useful to have a fast indication of the increased stress when multiple line outages occur. Reducing the bulk power transfer when the outages are severe could forestall further cascading of the outages. We show that synchrophasor measurements of voltage angles at all the area tie lines can be used to indicate the severity of multiple outages. These synchrophasor measurements are readily combined into an "area angle" that c...

  17. 47 CFR 4.5 - Definitions of outage, special offices and facilities, and 911 special facilities.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Definitions of outage, special offices and... Definitions of outage, special offices and facilities, and 911 special facilities. (a) Outage is defined as a...-911 tandems/selective routers for at least 30 minutes duration; or (3) One or more end-office or...

  18. Outage probability analysis for superposition coded symmetric relaying

    Institute of Scientific and Technical Information of China (English)

    WU Yi; ZHENG Meng; FEI ZeSong; LARSSON Erik G.; KUANG JingMing

    2013-01-01

    Superposition coded symmetric relaying is a bandwidth-efficient cooperative scheme where each source node simultaneously transmits both its own "local" packet and "relay" packet that originated at its partner by adding the modulated local and relay signals in Euclidean space. This paper investigates the power allocation and outage probability of a superposition coded symmetric relaying system with finite-constellation signaling. We first derive the mutual information (MI) metrics for the system. The derived MI metrics consist of two parts: one represents the MI conveyed by the modulated signal corresponding to its own data, and the other represents the MI conveyed by the modulated signal corresponding to its partner's data. Using MI based effective signal-to-noise ratio mapping technique, we attain expressions for the outage probability. Furthermore, we discuss power allocation policies that minimize the outage probability. Simulation results are presented to verify the correctness of the outage probability analysis and the benefits of the power allocation.

  19. Using Predictive Analytics to Predict Power Outages from Severe Weather

    Science.gov (United States)

    Wanik, D. W.; Anagnostou, E. N.; Hartman, B.; Frediani, M. E.; Astitha, M.

    2015-12-01

    The distribution of reliable power is essential to businesses, public services, and our daily lives. With the growing abundance of data being collected and created by industry (i.e. outage data), government agencies (i.e. land cover), and academia (i.e. weather forecasts), we can begin to tackle problems that previously seemed too complex to solve. In this session, we will present newly developed tools to aid decision-support challenges at electric distribution utilities that must mitigate, prepare for, respond to and recover from severe weather. We will show a performance evaluation of outage predictive models built for Eversource Energy (formerly Connecticut Light & Power) for storms of all types (i.e. blizzards, thunderstorms and hurricanes) and magnitudes (from 20 to >15,000 outages). High resolution weather simulations (simulated with the Weather and Research Forecast Model) were joined with utility outage data to calibrate four types of models: a decision tree (DT), random forest (RF), boosted gradient tree (BT) and an ensemble (ENS) decision tree regression that combined predictions from DT, RF and BT. The study shows that the ENS model forced with weather, infrastructure and land cover data was superior to the other models we evaluated, especially in terms of predicting the spatial distribution of outages. This research has the potential to be used for other critical infrastructure systems (such as telecommunications, drinking water and gas distribution networks), and can be readily expanded to the entire New England region to facilitate better planning and coordination among decision-makers when severe weather strikes.

  20. Desflurane Allows for a Faster Emergence when Compared to Sevoflurane Without Affecting the Baseline Cognitive Recovery Time.

    Directory of Open Access Journals (Sweden)

    Joseph G. Werner

    2015-10-01

    Full Text Available Aims, We compared the effect of desflurane and sevoflurane on anesthesia recovery time in patients undergoing urological cystoscopic surgery. The Short Orientation Memory Concentration Test (SOMCT measured and compared cognitive impairment between groups and coughing was assessed throughout the anesthetic.Methods and Materials, This investigation included 75 ambulatory patients. Patients were randomized to receive either desflurane or sevoflurane. Inhalational anesthetics were discontinued after removal of the cystoscope and once repositioning of the patient was final. Coughing assessment and awakening time from anesthesia were assessed by a blinded observer.Statistical analysis used: Statistical analysis was performed by using t-test for parametric variables and Mann-Whitney U test for nonparametric variables. Results, The primary endpoint, mean time to eye-opening, was 5.0±2.5 minutes for desflurane, and 7.9±4.1 minutes for sevoflurane (p <0.001. There were no significant differences in time to SOMCT recovery (p=0.109, overall time spent in the post anesthesia care unit (p=0.924 or time to discharge (p=0.363. Median time until readiness for discharge was nine minutes in the desflurane group, while the sevoflurane group had a median time of 20 minutes (p=0.020. The overall incidence of coughing during the perioperative period was significantly higher in the desflurane (p=0.030. Conclusions, We re-confirmed that patients receiving desflurane had a faster emergence and met the criteria to be discharged from the post anesthesia care unit earlier. No difference was found in time to return to baseline cognition between desflurane and sevoflurane.

  1. Hurricane Isaac: A Longitudinal Analysis of Storm Characteristics and Power Outage Risk.

    Science.gov (United States)

    Tonn, Gina L; Guikema, Seth D; Ferreira, Celso M; Quiring, Steven M

    2016-10-01

    In August 2012, Hurricane Isaac, a Category 1 hurricane at landfall, caused extensive power outages in Louisiana. The storm brought high winds, storm surge, and flooding to Louisiana, and power outages were widespread and prolonged. Hourly power outage data for the state of Louisiana were collected during the storm and analyzed. This analysis included correlation of hourly power outage figures by zip code with storm conditions including wind, rainfall, and storm surge using a nonparametric ensemble data mining approach. Results were analyzed to understand how correlation of power outages with storm conditions differed geographically within the state. This analysis provided insight on how rainfall and storm surge, along with wind, contribute to power outages in hurricanes. By conducting a longitudinal study of outages at the zip code level, we were able to gain insight into the causal drivers of power outages during hurricanes. Our analysis showed that the statistical importance of storm characteristic covariates to power outages varies geographically. For Hurricane Isaac, wind speed, precipitation, and previous outages generally had high importance, whereas storm surge had lower importance, even in zip codes that experienced significant surge. The results of this analysis can inform the development of power outage forecasting models, which often focus strictly on wind-related covariates. Our study of Hurricane Isaac indicates that inclusion of other covariates, particularly precipitation, may improve model accuracy and robustness across a range of storm conditions and geography.

  2. Outage analysis of interference-limited systems using STBC with co-channel MIMO interferers

    Institute of Scientific and Technical Information of China (English)

    Yongzhao LI; Leonard J.CIMINI,JR.; Nageen HIMAYAT

    2009-01-01

    The performance of Space-Time Block Coding (STBC) with co-channel MIMO interference is investigated.For an interference-limited environment, the closed-form ex-pressions for the probability density functions of the signal-to-interference ratio are derived and applied to analyze the outage probability with three typical types of co-channel MIMO interferers: STBC, open-loop spatial multiplexing and closed-loop spatial multiplexing. Both theoretical anal-yses and simulation results show that the performance of STBC is independent of the MIMO modes used in the in-terfering links.

  3. Outage and BER analysis for ultrawideband-based WPAN in Nakagami-m fading channels

    KAUST Repository

    Mehbodniya, Abolfazl

    2011-09-01

    This paper presents a performance analysis of multiband orthogonal frequency-division multiplexing (MB-OFDM) in ultra wideband (UWB)-based personal area networks (UPANs). A UPAN consists of devices with different UWB technologies at the physical layer. Approximate expressions for the outage probability and average bit error rate (BER) are derived in closed form for the MB-OFDM target receiver, taking into account multi-user interference (MUI), as well as external interference in the form of time-hopping (TH) and direct-sequence (DS) UWB signals. © 2010 IEEE.

  4. Electromagnetic organ tracking allows for real-time compensation of tissue shift in image-guided laparoscopic rectal surgery

    DEFF Research Database (Denmark)

    Wagner, Martin; Gondan, Matthias; Zöllner, Christian

    2016-01-01

    and intraoperative electromagnetic tracking(EMT) of the rectum. Methods. Three models were compared and evaluated for the compensation of tissue. deformation. For Model A no compensation was performed. Model B moved the corresponding points rigidly to the motion of the EMT sensor. Model C used five nested linear....... In laparoscopic rectal surgery the combination of electromagnetic organ tracking and preoperative imaging is a promising approach to compensate for intraoperative tissue shift in real-time....

  5. Outage analysis of opportunistic decode-and-forward relaying

    KAUST Repository

    Tourki, Kamel

    2010-09-01

    In this paper, we investigate a dual-hop opportunistic decode-and-forward relaying scheme where the source may or not be able to communicate directly with the destination. We first derive statistics based on exact probability density function (PDF) of each hop. Then, the PDFs are used to determine closed-form outage probability expression for a transmission rate R. Furthermore, we evaluate the asymptotic outage performance and the diversity order is deduced. Unlike existing works where the analysis focused on high signal-to-noise ratio (SNR) regime, such results are important to enable the designers to take decisions regarding practical systems that operate at low SNR regime. We show that performance simulation results coincide with our analytical results under practical assumption of unbalanced hops. © 2010 IEEE.

  6. Outage Constrained Secrecy Rate Maximization Using Cooperative Jamming

    CERN Document Server

    Luo, Shuangyu; Petropulu, Athina

    2012-01-01

    We consider a Gaussian MISO wiretap channel, where a multi-antenna source communicates with a single-antenna destination in the presence of a single-antenna eavesdropper. The communication is assisted by multi-antenna helpers that act as jammers to the eavesdropper. Each helper independently transmits noise which lies in the null space of the channel to the destination, thus creates no interference to the destination. Under the assumption that there is eavesdropper channel uncertainty, we derive the optimal covariance matrix for the source signal so that the secrecy rate is maximized subject to probability of outage and power constraints. Assuming that the eavesdropper channels follow zero-mean Gaussian model with known covariances, we derive the outage probability in a closed form. Simulation results in support of the analysis are provided.

  7. Outage Probability for Multi-Cell Processing under Rayleigh Fading

    CERN Document Server

    Garcia, Virgile; Lebedev, Nikolai

    2010-01-01

    Multi-cell processing, also called Coordinated Multiple Point (CoMP), is a very promising distributed multi-antennas technique that uses neighbour cell's antennas. This is expected to be part of next generation cellular networks standards such as LTE-A. Small cell networks in dense urban environment are mainly limited by interferences and CoMP can strongly take advantage of this fact to improve cell-edge users' throughput. This paper provides an analytical derivation of the capacity outage probability for CoMP experiencing fast Rayleigh fading. Only the average received power (slow varying fading) has to be known, and perfect Channel State Information (CSI) is not required. An optimisation of the successfully received data-rate is then derived with respect to the number of cooperating stations and the outage probability, illustrated by numerical examples.

  8. Power Allocation for Outage Minimization in Cognitive Radio Networks with Limited Feedback

    CERN Document Server

    He, Yuan Yuan

    2011-01-01

    We address an optimal transmit power allocation problem that minimizes the outage probability of a secondary user (SU) who is allowed to coexist with a primary user (PU) in a narrowband spectrum sharing cognitive radio network, under a long term average transmit power constraint at the secondary transmitter (SU-TX) and an average interference power constraint at the primary receiver (PU-RX), with quantized channel state information (CSI) (including both the channels from SU-TX to SU-RX, denoted as $g_1$ and the channel from SU-TX to PU-RX, denoted as $g_0$) at the SU-TX. The optimal quantization regions in the vector channel space is shown to have a 'stepwise' structure. With this structure, the above outage minimization problem can be explicitly formulated and solved by employing the Karush-Kuhn-Tucker (KKT) necessary optimality conditions to obtain a locally optimal quantized power codebook. A low-complexity near-optimal quantized power allocation algorithm is derived for the case of large number of feedbac...

  9. Inducement of IGA/SCC in Inconel 600 steam generator tubing during unit outages

    Energy Technology Data Exchange (ETDEWEB)

    Durance, D.; Sedman, K. [Bruce Power, Tiverton, Ontario (Canada); Roberts, J. [CANTECH Associates Ltd., Burlington, Ontario (Canada); King, P. [Babcock and Wilcox Canada, Cambridge, Ontario (Canada); Gorman, J. [Dominion Engineering, Reston, VA (United States); Allen, R. [Kinectrics, Inc., Toronto, Ontario (Canada)

    2008-07-01

    The degradation of Unit 4 SG tubing by IGA/SCC has limited both the operating period and end of life predictions for Unit 4 since restart in late 2003. The circumferential IGA/SCC has been most significant in SG4 with substantial increases in both initiation and growth rates from 2005 through the spring of 2007. A detailed review of the occurrence of circumferential OD IGA/SCC at the RTZ in the HL TTS region of Bruce 4 steam generator tubes has led a conclusion that it is probable that the IGA/SCC has been the result of attack by partially reduced sulfur species such as tetrathionates and thiosulfates during periods of low temperature exposure. It is believed that attack of this type has mostly likely occurred during startup evolutions following outages as the result the development of aggressive reduced sulfur species in the TTS region during periods when the boilers were fully drained for maintenance activities. The modification of outage practices to limit secondary side oxygen ingress in the spring of 2007 has apparently arrested the degradation and has had significant affects on the allowable operating interval and end of life predictions for the entire unit. (author)

  10. Metamodel-assisted evolutionary algorithms for the unit commitment problem with probabilistic outages

    Energy Technology Data Exchange (ETDEWEB)

    Georgopoulou, Chariklia A.; Giannakoglou, Kyriakos C. [National Technical University of Athens, School of Mechanical Engineering, Lab. of Thermal Turbomachines, Parallel CFD and Optimization Unit, P.O. Box 64069, Athens 157 10 (Greece)

    2010-05-15

    An efficient method for solving power generating unit commitment (UC) problems with probabilistic unit outages is proposed. It is based on a two-level evolutionary algorithm (EA) minimizing the expected total operating cost (TOC) of a system of power generating units over a scheduling period, with known failure and repair rates of each unit. To compute the cost function value of each EA population member, namely a candidate UC schedule, a Monte Carlo simulation must be carried out. Some thousands of replicates are generated according to the units' outage and repair rates and the corresponding probabilities. Each replicate is represented by a series of randomly generated availability and unavailability periods of time for each unit and the UC schedule under consideration accordingly. The expected TOC is the average of the TOCs of all Monte Carlo replicates. Therefore, the CPU cost per Monte Carlo evaluation increases noticeably and so does the CPU cost of running the EA. To reduce it, the use of a metamodel-assisted EA (MAEA) with on-line trained surrogate evaluation models or metamodels (namely, radial-basis function networks) is proposed. A novelty of this method is that the metamodels are trained on a few ''representative'' unit outage scenarios selected among the Monte Carlo replicates generated once during the optimization and, then, used to predict the expected TOC. Based on this low cost, approximate pre-evaluation, only a few top individuals within each generation undergo Monte Carlo simulations. The proposed MAEA is demonstrated on test problems and shown to drastically reduce the CPU cost, compared to EAs which are exclusively based on Monte Carlo simulations. (author)

  11. Outage probability of distributed beamforming with co-channel interference

    KAUST Repository

    Yang, Liang

    2012-03-01

    In this letter, we consider a distributed beamforming scheme (DBF) in the presence of equal-power co-channel interferers for both amplify-and-forward and decode-and-forward relaying protocols over Rayleigh fading channels. We first derive outage probability expressions for the DBF systems. We then present a performance analysis for a scheme relying on source selection. Numerical results are finally presented to verify our analysis. © 2011 IEEE.

  12. Distortion outage minimization in Nakagami fading using limited feedback

    Science.gov (United States)

    Wang, Chih-Hong; Dey, Subhrakanti

    2011-12-01

    We focus on a decentralized estimation problem via a clustered wireless sensor network measuring a random Gaussian source where the clusterheads amplify and forward their received signals (from the intra-cluster sensors) over orthogonal independent stationary Nakagami fading channels to a remote fusion center that reconstructs an estimate of the original source. The objective of this paper is to design clusterhead transmit power allocation policies to minimize the distortion outage probability at the fusion center, subject to an expected sum transmit power constraint. In the case when full channel state information (CSI) is available at the clusterhead transmitters, the optimization problem can be shown to be convex and is solved exactly. When only rate-limited channel feedback is available, we design a number of computationally efficient sub-optimal power allocation algorithms to solve the associated non-convex optimization problem. We also derive an approximation for the diversity order of the distortion outage probability in the limit when the average transmission power goes to infinity. Numerical results illustrate that the sub-optimal power allocation algorithms perform very well and can close the outage probability gap between the constant power allocation (no CSI) and full CSI-based optimal power allocation with only 3-4 bits of channel feedback.

  13. Outage Probability Analysis of FSO Links over Foggy Channel

    KAUST Repository

    Esmail, Maged Abdullah

    2017-02-22

    Outdoor Free space optic (FSO) communication systems are sensitive to atmospheric impairments such as turbulence and fog, in addition to being subject to pointing errors. Fog is particularly severe because it induces an attenuation that may vary from few dBs up to few hundreds of dBs per kilometer. Pointing errors also distort the link alignment and cause signal fading. In this paper, we investigate and analyze the FSO systems performance under fog conditions and pointing errors in terms of outage probability. We then study the impact of several effective communication mitigation techniques that can improve the system performance including multi-hop, transmit laser selection (TLS) and hybrid RF/FSO transmission. Closed-form expressions for the outage probability are derived and practical and comprehensive numerical examples are suggested to assess the obtained results. We found that the FSO system has limited performance that prevents applying FSO in wireless microcells that have a 500 m minimum cell radius. The performance degrades more when pointing errors appear. Increasing the transmitted power can improve the performance under light to moderate fog. However, under thick and dense fog the improvement is negligible. Using mitigation techniques can play a major role in improving the range and outage probability.

  14. Controlled Tripping of Overheated Lines Mitigates Power Outages

    CERN Document Server

    Pfitzner, René; Chertkov, Michael

    2011-01-01

    We study cascades of blackouts in the model of the Polish (transmission) power grid (2700 nodes and 3504 transmission lines). A cascade is initiated by a sufficiently severe initial contingency tripping. The cascade advances via sequential tripping of many more overheated lines (with the thermal limits exceeded), islanding loads and generators and eventually arriving at a fixed point with the surviving part of the system being power- flow-balanced and the rest of the system being outaged. Utilizing the quasi-static model for cascade propagation, introduced in our earlier study (Statistical Classification of Cascading Failures in Power Grids, IEEE PES GM 2011), we analyze how the severity of the cascade depends on the order of tripping overheated lines. Our main observation is that the order of tripping has a tremendous effect on the size of the resulting outage: the probability distribution function of the outage size is broad; moreover in many of the cases studied, picking an overheated line at random result...

  15. Oscillation-Driven Spike-Timing Dependent Plasticity Allows Multiple Overlapping Pattern Recognition in Inhibitory Interneuron Networks

    DEFF Research Database (Denmark)

    Garrido, Jesús A.; Luque, Niceto R.; Tolu, Silvia

    2016-01-01

    understood. Here, we have used a simple model of afferent excitatory neurons and interneurons with lateral inhibition, reproducing a network topology found in many brain areas from the cerebellum to cortical columns. When endowed with spike-timing dependent plasticity (STDP) at the excitatory input synapses...... and at the inhibitory interneuron-interneuron synapses, the interneurons rapidly learned complex input patterns. Interestingly, induction of plasticity required that the network be entrained into theta-frequency band oscillations, setting the internal phase-reference required to drive STDP. Inhibitory plasticity...... patterns. The combination of plasticity in lateral inhibitory connections and homeostatic mechanisms in the inhibitory interneurons optimized mutual information (MI) transfer. The storage of multiple complex patterns in plastic interneuron networks could be critical for the generation of sparse...

  16. Grid-connected photovoltaic (PV) systems with batteries storage as solution to electrical grid outages in Burkina Faso

    Science.gov (United States)

    Abdoulaye, D.; Koalaga, Z.; Zougmore, F.

    2012-02-01

    This paper deals with a key solution for power outages problem experienced by many African countries and this through grid-connected photovoltaic (PV) systems with batteries storage. African grids are characterized by an insufficient power supply and frequent interruptions. Due to this fact, users who especially use classical grid-connected photovoltaic systems are unable to profit from their installation even if there is sun. In this study, we suggest the using of a grid-connected photovoltaic system with batteries storage as a solution to these problems. This photovoltaic system works by injecting the surplus of electricity production into grid and can also deliver electricity as a stand-alone system with all security needed. To achieve our study objectives, firstly we conducted a survey of a real situation of one African electrical grid, the case of Burkina Faso (SONABEL: National Electricity Company of Burkina). Secondly, as study case, we undertake a sizing, a modeling and a simulation of a grid-connected PV system with batteries storage for the LAME laboratory at the University of Ouagadougou. The simulation shows that the proposed grid-connected system allows users to profit from their photovoltaic installation at any time even if the public electrical grid has some failures either during the day or at night.

  17. World class outage performance in Malaysia

    Energy Technology Data Exchange (ETDEWEB)

    Burchardt, H.E. [YTL Power Services, Kuala Lumpur (Malaysia)

    1999-06-01

    This article reports on the performance of the Malaysian Paka and Pasir Gudang combined cycle power plants, and gives details of their maintenance and operation, the planning of inspections and overhauls, and the factors contributing to the reductions in overhaul times that have been achieved.

  18. Pricing power outages in the Netherlands

    NARCIS (Netherlands)

    Baarsma, B.E.; Hop, J.P.

    2009-01-01

    In most Western countries, the power grid provides electricity more than 99% of the time. To maintain reliability at such high levels, energy companies have to continually invest in electric transmission- and distribution systems. Since customers of electricity cannot switch from one distribution ne

  19. Cascading Power Outages Propagate Locally in an Influence Graph that is not the Actual Grid Topology

    CERN Document Server

    Hines, Paul D H; Rezaei, Pooya

    2015-01-01

    In a cascading power transmission outage, component outages propagate non-locally; after one component outages, the next failure may be very distant, both topologically and geographically. As a result, simple models of topological contagion do not accurately represent the propagation of cascades in power systems. However, cascading power outages do follow patterns, some of which are useful in understanding and reducing blackout risk. This paper describes a method by which the data from many cascading failure simulations can be transformed into a graph-based model of influences that provides actionable information about the many ways that cascades propagate in a particular system. The resulting "influence graph" model is Markovian, since component outage probabilities depend only on the outages that occurred in the prior generation. To validate the model we compare the distribution of cascade sizes resulting from n-2 contingencies in a 2896 branch test case to cascade sizes in the influence graph. The two dist...

  20. Hybrid Model for Cascading Outage in a Power System: A Numerical Study

    Science.gov (United States)

    Susuki, Yoshihiko; Takatsuji, Yu; Hikihara, Takashi

    Analysis of cascading outages in power systems is important for understanding why large blackouts emerge and how to prevent them. Cascading outages are complex dynamics of power systems, and one cause of them is the interaction between swing dynamics of synchronous machines and protection operation of relays and circuit breakers. This paper uses hybrid dynamical systems as a mathematical model for cascading outages caused by the interaction. Hybrid dynamical systems can combine families of flows describing swing dynamics with switching rules that are based on protection operation. This paper refers to data on a cascading outage in the September 2003 blackout in Italy and shows a hybrid dynamical system by which propagation of outages reproduced is consistent with the data. This result suggests that hybrid dynamical systems can provide an effective model for the analysis of cascading outages in power systems.

  1. Outage Probability of General Ad Hoc Networks in the High-Reliability Regime

    CERN Document Server

    Giacomelli, Riccardo; Haenggi, Martin

    2010-01-01

    Outage probabilities in wireless networks depend on various factors: the node distribution, the MAC scheme, and the models for path loss, fading and transmission success. In prior work on outage characterization for networks with randomly placed nodes, most of the emphasis was put on networks whose nodes are Poisson distributed and where ALOHA is used as the MAC protocol. In this paper we provide a general framework for the analysis of outage probabilities in the high-reliability regime. The outage probability characterization is based on two parameters: the intrinsic spatial contention $\\gamma$ of the network, introduced in [1], and the coordination level achieved by the MAC as measured by the interference scaling exponent $\\kappa$ introduced in this paper. We study outage probabilities under the signal-to-interference ratio (SIR) model, Rayleigh fading, and power-law path loss, and explain how the two parameters depend on the network model. The main result is that the outage probability approaches $\\gamma\\e...

  2. On Outage Performance of Spectrum-Sharing Communication over M-Block Fading

    KAUST Repository

    Alabbasi, AbdulRahman

    2015-12-06

    In this paper, we consider a cognitive radio system in which a block-fading channel is assumed. Each transmission frame consists of M blocks and each block undergoes a different channel gain. Instantaneous channel state information about the interference links remains unknown to the primary and secondary users. We minimize the secondary user\\'s targeted outage probability over the block-fading channels. To protect the primary user, a statistical constraint on its targeted outage probability is enforced. The secondary user\\'s targeted outage region and the corresponding optimal power are derived. We also propose two sub-optimal power strategies and derive compact expressions for the corresponding outage probabilities. These probabilities are shown to be asymptotic lower and upper bounds on the outage probability. Utilizing these bounds, we derive the exact diversity order of the secondary user outage probability. Selected numerical results are presented to characterize the system\\'s behavior.

  3. Optimal utilization of outages. The tasks of the OEM and/or service provider

    Energy Technology Data Exchange (ETDEWEB)

    Jakobs, Norbert [Siemens AG, Nuclear Power Generation Division, D-91050 Erlangen (Germany); Grauf, Eberhard [Gemeinschaftskernkraftwerk Neckar GmbH, im Steinbruch, D-74382 Neckarwestheim (Germany)

    1998-07-01

    The deregulation of Europe's power market on January 1, 1999 will force many electric utilities and especially nuclear power plant operators to introduce extensive cost-cutting measures in order that they can hold their own in the new competitive environment. Existing plants basically have three potential ways of reducing their power generating costs: by increasing availability, reducing fuel costs and cutting back operating costs. Optimizing plant outages provides considerable potential for raising plant availability but can also lower operating costs by reducing expenditure on maintenance. In order to optimize an outage in terms of performance time and cost, there are a number of starting points based on certain key factors: organization, planning, logistics, performance monitoring, plant and equipment enhancements as well as personnel motivation. To reach this goal it is necessary for the original equipment manufacturer (OEM) and/or service provider to be involved in these activities to a much greater extent than before and for a closer form of partnership to be established with the consumer. For it is only within a team having a common set of goals that the successes of the past have been able to be achieved and new tasks can be efficiently handled in the future. (author)

  4. Coordinate Update Algorithms for Robust Power Loading for the MU-MISO Downlink With Outage Constraints

    Science.gov (United States)

    Sohrabi, Foad; Davidson, Timothy N.

    2016-06-01

    We consider the problem of power allocation for the single-cell multi-user (MU) multiple-input single-output (MISO) downlink with quality-of-service (QoS) constraints. The base station acquires an estimate of the channels and, for a given beamforming structure, designs the power allocation so as to minimize the total transmission power required to ensure that target signal-to-interference-and-noise ratios at the receivers are met, subject to a specified outage probability. We consider scenarios in which the errors in the base station's channel estimates can be modelled as being zero-mean and Gaussian. Such a model is particularly suitable for time division duplex (TDD) systems with quasi-static channels, in which the base station estimates the channel during the uplink phase. Under that model, we employ a precise deterministic characterization of the outage probability to transform the chance-constrained formulation to a deterministic one. Although that deterministic formulation is not convex, we develop a coordinate descent algorithm that can be shown to converge to a globally optimal solution when the starting point is feasible. Insight into the structure of the deterministic formulation yields approximations that result in coordinate update algorithms with good performance and significantly lower computational cost. The proposed algorithms provide better performance than existing robust power loading algorithms that are based on tractable conservative approximations, and can even provide better performance than robust precoding algorithms based on such approximations.

  5. The Opportunity Cost of Electricity Outages and Privatization of Substations in Nepal

    OpenAIRE

    Roop Jyoti; Aygul Ozbafli; Glenn Jenkins

    2006-01-01

    The unreliability of electricity supplies is a major cause of the high cost of manufacturing in developing countries. In this paper, we are able to measure the cost imposed by power outages and suggest some feasible mitigating measures. The study employs a rich, if not unique, set of data from three large manufacturing enterprises in Nepal. Using it, the opportunity costs to the enterprises from lost production from electricity outages can be estimated accurately. Power outages due to substat...

  6. Separating the Effect of Independent Interference Sources with Rayleigh Faded Signal Link: Outage Analysis and Applications

    CERN Document Server

    Kahlon, Arshdeep S; Periyalwar, Shalini; Yanikomeroglu, Halim

    2012-01-01

    We show that, for independent interfering sources and a signal link with exponentially distributed received power, the total probability of outage can be decomposed as a simple expression of the outages from the individual interfering sources. We give a mathematical proof of this result, and discuss some immediate implications, showing how it results in important simplifications to statistical outage analysis. We also discuss its application to two active topics of study: spectrum sharing, and sum of interference powers (e.g., lognormal) analysis.

  7. Hybrid Model for Cascading Outage in a Power System: A Numerical Study

    OpenAIRE

    Susuki, Yoshihiko; Takatsuji, Yu; Hikihara, Takashi

    2009-01-01

    Analysis of cascading outages in power systems is important for understanding why large blackouts emerge and how to prevent them. Cascading outages are complex dynamics of power systems, and one cause of them is the interaction between swing dynamics of synchronous machines and protection operation of relays and circuit breakers. This paper uses hybrid dynamical systems as a mathematical model for cascading outages caused by the interaction. Hybrid dynamical systems can combine families of fl...

  8. Areva: experiences in outage services; Areva: experiencias en servicios de recarga

    Energy Technology Data Exchange (ETDEWEB)

    Wiemeier, R.; Mueller, N.; Blanco, I. J.

    2010-07-01

    As the world leader in the nuclear industry, Areva is firmly committed to the safe and reliable operation of the Spanish nuclear power plants. Following this commitment, Areva has established the subsidiary Areva NP Services Spain as a local platform to provide nuclear services for the Spanish nuclear power plants. being integrated and supported by the global Areva Group, Areva NP Services Spain is able to offer services solutions to all customers demands while maintaining close and sustainable relationships with them. This integration also allows the Spanish personnel of Areva to employ their skills by working in multinational teams in international projects. This article will present the capacities, and the most important recent national and international project performed by Areva NP Services Spain in the field of outage services. (Author)

  9. An EOQ model for time-dependent deteriorating items with alternating demand rates allowing shortages by considering time value of money

    Directory of Open Access Journals (Sweden)

    Kundu Antara

    2013-01-01

    Full Text Available The present paper deals with an economic order quantity (EOQ model of an inventory problem with alternating demand rate: (i For a certain period, the demand rate is a non linear function of the instantaneous inventory level. (ii For the rest of the cycle, the demand rate is time dependent. The time at which demand rate changes, may be deterministic or uncertain. The deterioration rate of the item is time dependent. The holding cost and shortage cost are taken as a linear function of time. The total cost function per unit time is obtained. Finally, the model is solved using a gradient based non-linear optimization technique (LINGO and is illustrated by a numerical example.

  10. Operational Readiness Verification, Phase 3. A Field Study at a Swedish NPP during a Productive Outage (Safety-train Outage)

    Energy Technology Data Exchange (ETDEWEB)

    Hollnagel, Erik [Linkoeping Univ. (Sweden). Dept. of Computer and Information Science; Gauthereau, Vincent; Persson, Bodil [Linkoeping Univ. (Sweden). Dept. of Industrial Engineering

    2004-01-01

    This report describes the results from Phase III of a study on Operational Readiness Verification (ORV) that was carried out from December 2002 to November 2003. The work comprised a field study of ORV activities at a Swedish NPP during a planned productive outage, which allowed empirical work to be conducted in an appropriate environment with good accessibility to technical staff. One conclusion from Phase I of this project was the need to look more closely at the differences between three levels or types of tests that occur in ORV: object (component) test, system level test and (safety) function test, and to analyse the different steps of testing in order to understand the nontrivial relations between tests and safety. A second conclusion was the need to take a closer look at the organisation's ability to improvise in the sense of adjusting pre-defined plans to the actual conditions under which they are to be carried out. Phase II of the project found that although all three types of test occurred, they were rather used according to need rather than to a predefined arrangement or procedure. The complexity of ORV could be understood and described by using the concepts of Community of Practice, embedding, and Efficiency-Thoroughness Trade-Off. In addition, organisation and the different communities of practice improvise by adjusting pre-defined plans or work orders to the existing conditions. Such improvisations take place both on the levels of individual actions, on the level of communities of practice, and on the organisational level. The ability to improvise is practically a necessity for work to be carried out, but is also a potential risk. Phase III of the project studied how tasks are adapted relative to the different types of embedding and the degree of correspondence between nominal and actual ORV. It also looked further at the different Communities of Practice that are part of maintenance and ORV, focusing on the coordination and communication between

  11. Outage analysis for underlay cognitive networks using incremental regenerative relaying

    KAUST Repository

    Tourki, Kamel

    2013-02-01

    Cooperative relay technology has recently been introduced into cognitive radio (CR) networks to enhance the network capacity, scalability, and reliability of end-to-end communication. In this paper, we investigate an underlay cognitive network where the quality of service (QoS) of the secondary link is maintained by triggering an opportunistic regenerative relaying once it falls under an unacceptable level. Analysis is conducted for two schemes, referred to as the channel-state information (CSI)-based and fault-tolerant schemes, respectively, where different amounts of CSI were considered. We first provide the exact cumulative distribution function (cdf) of the received signal-to-noise ratio (SNR) over each hop with colocated relays. Then, the cdf\\'s are used to determine a very accurate closed-form expression for the outage probability for a transmission rate $R$. In a high-SNR region, a floor of the secondary outage probability occurs, and we derive its corresponding expression. We validate our analysis by showing that the simulation results coincide with our analytical results in Rayleigh fading channels. © 1967-2012 IEEE.

  12. On the Outage Behavior of Asynchronous OFDM DF and AF Cooperative Networks

    CERN Document Server

    Torbatian, Mehdi

    2009-01-01

    The outage behavior of various relaying protocols over a general one hop asynchronous cooperative network is examined when orthogonal frequency division multiplexing (OFDM) is used to combat synchronization error among the relays. We consider non-orthogonal selection decode-and-forward (NSDF), orthogonal selection decode-and-forward (OSDF), non-orthogonal amplify-and-forward (NAF), and orthogonal amplify-and-forward (OAF) relaying protocols and analyze the diversity multiplexing gain tradeoff (DMT) in all scenarios. The transmitting nodes cooperatively construct an asynchronous OFDM space-time code by re-sending the source messages over a common time interval and a common frequency bandwidth. It is shown that in decode-and-forward (DF) type protocols, the asynchronous network provides a diversity gain greater than or equal to the one of the corresponding synchronous network in the limit of code word length and throughout the range of multiplexing gain. In amplify-and-forward (AF) type protocols, in which the ...

  13. 77 FR 25088 - Extension of the Commission's Rules Regarding Outage Reporting to Interconnected Voice Over...

    Science.gov (United States)

    2012-04-27

    ..., nationwide view of significant outages and assess and address their impact on 9-1-1 and other services, while... persuaded that any new outage reporting process should apply the voluntary DIRS model. DIRS is a reporting... applicable to the owners and controllers of 9-1-1 facilities, who are ILECs, CLECs, and third-party...

  14. Outage probability of opportunistic decode-and-forward relaying over Nakagami-m fading channels

    Institute of Scientific and Technical Information of China (English)

    CHUAI Gang; ZHANG Bao-zhi; LIU Xing-mei; GAO Li

    2009-01-01

    In this article, the outage probability behavior of a relay network over Nakagami-m fading channels is analyzed. Both reactive and proactive opportunistic decode-and-forward (DAF) strategies are considered. The closed-form solutions to the outage probabilities on both opportunistic DAF strategies are derived. Simulation results conf'Lrrn the presented mathematical analysis.

  15. Unified Importance Sampling Schemes for Efficient Simulation of Outage Capacity over Generalized Fading Channels

    KAUST Repository

    Rached, Nadhir B.

    2015-11-13

    The outage capacity (OC) is among the most important performance metrics of communication systems operating over fading channels. Of interest in the present paper is the evaluation of the OC at the output of the Equal Gain Combining (EGC) and the Maximum Ratio Combining (MRC) receivers. In this case, it can be seen that this problem turns out to be that of computing the Cumulative Distribution Function (CDF) for the sum of independent random variables. Since finding a closedform expression for the CDF of the sum distribution is out of reach for a wide class of commonly used distributions, methods based on Monte Carlo (MC) simulations take pride of price. In order to allow for the estimation of the operating range of small outage probabilities, it is of paramount importance to develop fast and efficient estimation methods as naive Monte Carlo (MC) simulations would require high computational complexity. In this line, we propose in this work two unified, yet efficient, hazard rate twisting Importance Sampling (IS) based approaches that efficiently estimate the OC of MRC or EGC diversity techniques over generalized independent fading channels. The first estimator is shown to possess the asymptotic optimality criterion and applies for arbitrary fading models, whereas the second one achieves the well-desired bounded relative error property for the majority of the well-known fading variates. Moreover, the second estimator is shown to achieve the asymptotic optimality property under the particular Log-normal environment. Some selected simulation results are finally provided in order to illustrate the substantial computational gain achieved by the proposed IS schemes over naive MC simulations.

  16. Home Use Devices: How to Prepare for and Handle Power Outages for Medical Devices That Require Electricity

    Science.gov (United States)

    ... Handle Power Outages for Medical Devices that Require Electricity Center for De CDRH vices and Rad lth ... Handle Power Outages for Medical Devices that Require Electricity As a home medical device user, it is ...

  17. Outage Probability and Power Allocation for Two-Way DF Relay Networks with Relay Selection

    Directory of Open Access Journals (Sweden)

    Z. Fan

    2012-09-01

    Full Text Available In this paper, we investigate the outage probability and power allocation for the two-way decode-and-forward (DF relay networks with relay selection.~Specially, we consider independent but not necessarily identical distributed Rayleigh fading channels. Firstly, we derive an exact closed form outage probability expression. To shed light on the relation between the outage probability and the power allocation factor, an upper bound for the outage probability is derived, too. We then propose a power allocation scheme in the sense of minimizing this upper bound. Monte Carlo simulations are conducted to show that the derived outage probability expression excellently matches simulation results, and our proposed power allocation scheme performs effectively.

  18. Reliability assessment to determine the optimal forced outage rate of components

    Directory of Open Access Journals (Sweden)

    Habib Daryabad

    2014-03-01

    Full Text Available Determining the optimal forced outage rate (FOR ofcomponents can lead to reducing the operational and maintenance costs inelectric power systems. FOR is closely associated with two factors: number ofoutages and duration of outages. Therefore, it is possible to decrease the FORthrough decreasing the number of outages or reducing the duration ofoutages. Decreasing number of outages is usually carried out throughreinforcement of the network and reducing the duration of outages is mainlyperformed through increasing the repair and maintenance groups. Both of theproposed methods to decrease the FOR possess the costs. Therefore, it is verysuitable to find the optimal rate of FOR and avoiding unnecessary costs. Thispaper presents a new methodology to find the optimal rate of FOR. In thisregard, the system reliability is assessed and evaluated from view of FOR andthe optimal rate of FOR is denoted for all components.

  19. Estimating Power Outage Cost based on a Survey for Industrial Customers

    Science.gov (United States)

    Yoshida, Yoshikuni; Matsuhashi, Ryuji

    A survey was conducted on power outage cost for industrial customers. 5139 factories, which are designated energy management factories in Japan, answered their power consumption and the loss of production value due to the power outage in an hour in summer weekday. The median of unit cost of power outage of whole sectors is estimated as 672 yen/kWh. The sector of services for amusement and hobbies and the sector of manufacture of information and communication electronics equipment relatively have higher unit cost of power outage. Direct damage cost from power outage in whole sectors reaches 77 billion yen. Then utilizing input-output analysis, we estimated indirect damage cost that is caused by the repercussion of production halt. Indirect damage cost in whole sectors reaches 91 billion yen. The sector of wholesale and retail trade has the largest direct damage cost. The sector of manufacture of transportation equipment has the largest indirect damage cost.

  20. A multi-state model for wind farms considering operational outage probability

    DEFF Research Database (Denmark)

    Cheng, Lin; Liu, Manjun; Sun, Yuanzhang;

    2013-01-01

    power penetration levels. Therefore, a more comprehensive analysis toward WECS as well as an appropriate reliability assessment model are essential for maintaining the reliable operation of power systems. In this paper, the impact of wind turbine outage probability on system reliability is firstly......As one of the most important renewable energy resources, wind power has drawn much attention in recent years. The stochastic characteristics of wind speed lead to generation output uncertainties of wind energy conversion system (WECS) and affect power system reliability, especially at high wind...... developed by considering the following factors: running time, operating environment, operating conditions, and wind speed fluctuations. A multi-state model for wind farms is also established. Numerical results illustrate that the proposed model can be well applied to power system reliability assessment...

  1. Outage Analysis of PLNC Based Bidirectional Relay Network in the presence of I/Q Imbalance

    Directory of Open Access Journals (Sweden)

    V.N.Senthil Kumaran

    2014-08-01

    Full Text Available Bidirectional relay network consists of two sources and a relay, where each node has a single antenna and operates in half duplex mode. The PLNC based OFDM system transmits numerous high data streams through narrow band flat fading subchannels to achieve high spectral efficiency over wide band channels. However in practice, I/Q imbalance is introduced at the radio frequency sections of the nodes affects the orthogonality among the subcarriers. In this paper, the bidirectional relay network is modelled with I/Q imbalance and the outage performance of Orthogonal Frequency Division Multiplexing (OFDM based bidirectional relay network which employs physical layer network coding (PLNC is analyzed in the presence of In-phase and Quadrature (I/Q imbalance at both the time slots.

  2. Asymmetric Hardware Distortions in Receive Diversity Systems: Outage Performance Analysis

    KAUST Repository

    Javed, Sidrah

    2017-02-22

    This paper studies the impact of asymmetric hardware distortion (HWD) on the performance of receive diversity systems using linear and switched combining receivers. The asymmetric attribute of the proposed model motivates the employment of improper Gaussian signaling (IGS) scheme rather than the traditional proper Gaussian signaling (PGS) scheme. The achievable rate performance is analyzed for the ideal and non-ideal hardware scenarios using PGS and IGS transmission schemes for different combining receivers. In addition, the IGS statistical characteristics are optimized to maximize the achievable rate performance. Moreover, the outage probability performance of the receive diversity systems is analyzed yielding closed form expressions for both PGS and IGS based transmission schemes. HWD systems that employ IGS is proven to efficiently combat the self interference caused by the HWD. Furthermore, the obtained analytic expressions are validated through Monte-Carlo simulations. Eventually, non-ideal hardware transceivers degradation and IGS scheme acquired compensation are quantified through suitable numerical results.

  3. Outage analysis for underlay relay-assisted cognitive networks

    KAUST Repository

    Tourki, Kamel

    2012-12-01

    Cooperative relay technology was recently introduced into cognitive radio networks in order to enhance network capacity, scalability, and reliability of end-to-end communication. In this paper, we investigate an underlay cognitive network where the quality of service of the secondary link is maintained by triggering an opportunistic regenerative relaying once it falls under an unacceptable level. We first provide the exact cumulative density function (CDF) of received signal-to-noise (SNR) over each hop with co-located relays. Then, the CDFs are used to determine very accurate closed-form expression for the outage probability for a transmission rate R. We validate our analysis by showing that simulation results coincide with our analytical results in Rayleigh fading channels. © 2012 IEEE.

  4. Power outages, extreme events and health: a systematic review of the literature from 2011-2012.

    Science.gov (United States)

    Klinger, Chaamala; Landeg, Owen; Murray, Virginia

    2014-01-02

    Background Extreme events (e.g. flooding) threaten critical infrastructure including power supplies. Many interlinked systems in the modern world depend on a reliable power supply to function effectively. The health sector is no exception, but the impact of power outages on health is poorly understood. Greater understanding is essential so that adverse health impacts can be prevented and/or mitigated. Methods We searched Medline, CINAHL and Scopus for papers about the health impacts of power outages during extreme events published in 2011-2012. A thematic analysis was undertaken on the extracted information. The Public Health England Extreme Events Bulletins between 01/01/2013 - 31/03/2013 were used to identify extreme events that led to power outages during this three-month period. Results We identified 20 relevant articles. Power outages were found to impact health at many levels within diverse settings. Recurrent themes included the difficulties of accessing healthcare, maintaining frontline services and the challenges of community healthcare. We identified 52 power outages in 19 countries that were the direct consequence of extreme events during the first three months of 2013. Conclusions To our knowledge, this is the first review of the health impacts of power outages. We found the current evidence and knowledge base to be poor. With scientific consensus predicting an increase in the frequency and magnitude of extreme events due to climate change, the gaps in knowledge need to be addressed in order to mitigate the impact of power outages on global health.

  5. Bringing well service into the digital age : new software and digital pens allow for real-time tracking of field data

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2010-09-15

    This article discussed a paperwork automation system that was implemented at a well services company and the efficiencies that were gained as a result of the implementation. The company's highly mobile delivery and service teams needed access to real-time delivery, inventory, and billing data, which the paper-based data management system then in place was unable to provide. The automated system incorporates new software and digital pens, which digitize handwriting and integrate the data directly into software. The new system allows for the real-time tracking of field data without disruption to existing employee processes or the necessity of a large investment in new computer infrastructure. The new system reduces the costs associated with paper-based data collection processes, including printing, form data re-keying, scanning, and storage. It also eliminates delays in reporting and billing and allows accurate inventory tracking throughout the supply chain as well as improved management of inventory levels. 2 refs., 2 figs.

  6. Simultaneous effects of allowed time, teaching method, ability, and student assessment of treatment on achievement in a high school biology course (ISIS)

    Science.gov (United States)

    Burkman, Ernest; Brezin, Michael; Griffin, Patrick

    The simultaneous effects of teaching method (self-directed, group directed, and teacher directed), allowed time for study, and two student variables (academic ability and assessment of treatment implementation) are described for student achievement in a high school biology course (ISIS). The variable student assessment of treatment implementation was viewed as a particularly important variable for two reasons: (1) in research by Stayrook, Corno, and Winne (1978) it has accounted for as much variance in achievement as the assigned treatment; and (2) it provides a means for controlling the range of implementation of teaching methods. A between-student analysis resulted in a description of effects complicated by interactions among all the variables. While the interactions were particularly strong in the student-directed method, it may generally be concluded that as time allowed for study decreased, students who perceived the treatment as being well implemented tended to have higher achievement. Also, it was found that the main effect of ability was quite strong. The results confirmed the importance of student assessment of treatment implementation as a descriptive variable. Additionally, the results suggest a qualification in the conclusion of Cronbach and Snow (1971) that individualized instruction tends to favor high-ability students; that conclusion may need to be modified to situations in which students fully perceive their autonomy.

  7. Optimal Power Allocation for Fading Channels in Cognitive Radio Networks: Ergodic Capacity and Outage Capacity

    CERN Document Server

    Kang, Xin; Nallanathan, Arumugam; Garg, Hari Krishna; Zhang, Rui

    2008-01-01

    A cognitive radio network (CRN) is formed by either allowing the secondary users (SUs) in a secondary communication network (SCN) to opportunistically operate in the frequency bands originally allocated to a primary communication network (PCN) or by allowing SCN to coexist with the primary users (PUs) in PCN as long as the interference caused by SCN to each PU is properly regulated. In this paper, we consider the latter case, known as spectrum sharing, and study the optimal power allocation strategies to achieve the ergodic capacity and the outage capacity of the SU fading channel under different types of power constraints and fading channel models. In particular, besides the interference power constraint at PU, the transmit power constraint of SU is also considered. Since the transmit power and the interference power can be limited either by a peak or an average constraint, various combinations of power constraints are studied. It is shown that there is a capacity gain for SU under the average over the peak ...

  8. Heterologous Matrix Metalloproteinase Gene Promoter Activity Allows In Vivo Real-time Imaging of Bleomycin-Induced Lung Fibrosis in Transiently Transgenized Mice

    Science.gov (United States)

    Stellari, Fabio Franco; Ruscitti, Francesca; Pompilio, Daniela; Ravanetti, Francesca; Tebaldi, Giulia; Macchi, Francesca; Verna, Andrea Elizabeth; Villetti, Gino; Donofrio, Gaetano

    2017-01-01

    Idiopathic pulmonary fibrosis is a very common interstitial lung disease derived from chronic inflammatory insults, characterized by massive scar tissue deposition that causes the progressive loss of lung function and subsequent death for respiratory failure. Bleomycin is used as the standard agent to induce experimental pulmonary fibrosis in animal models for the study of its pathogenesis. However, to visualize the establishment of lung fibrosis after treatment, the animal sacrifice is necessary. Thus, the aim of this study was to avoid this limitation by using an innovative approach based on a double bleomycin treatment protocol, along with the in vivo images analysis of bleomycin-treated mice. A reporter gene construct, containing the luciferase open reading frame under the matrix metalloproteinase-1 promoter control region, was tested on double bleomycin-treated mice to investigate, in real time, the correlation between bleomycin treatment, inflammation, tissue remodeling and fibrosis. Bioluminescence emitted by the lungs of bleomycin-treated mice, corroborated by fluorescent molecular tomography, successfully allowed real time monitoring of fibrosis establishment. The reporter gene technology experienced in this work could represent an advanced functional approach for real time non-invasive assessment of disease evolution during therapy, in a reliable and translational living animal model. PMID:28298912

  9. Research and Practice of DC Power Double Renovation without Power Outage%直流电源双重化改造不停电策略研究与实践

    Institute of Scientific and Technical Information of China (English)

    仇群辉; 傅进; 费云中; 颜彦

    2015-01-01

    结合直流电源双重化改造实践,对一次设备停电方式、保护轮停方式和不停电方式下设备操作量、操作时间、作业人数以及改造时间进行比较分析,研究出一种不停电改造方法并建议推广应用。%Through double renovation of DC power, equipment operation amount, operation time, number of operators and renovation time of primary equipment outage, alternate outage of relay protection and non-out-age are compared and analyzed. In the final, a non-outage scheme is developed and widely applied.

  10. An approach to implement PSO to optimize outage probability of coded cooperative communication with multiple relays

    Directory of Open Access Journals (Sweden)

    Sindhu Hak Gupta

    2016-09-01

    Full Text Available Coded Cooperative Communication is a novel concept and it is the solution to utilize the benefits of MIMO (Multiple Input Multiple Output gains on distributed scale. In this paper the outage behavior of coded cooperative communication with multiple relays is examined. The numerical expression for outage probability is derived. Nakagami-m fading statics is considered. Outage probability is observed to be function of various free and constrained parameters. An approach is presented to implement PSO and optimize the free parameters on which outage probability of coded cooperative communication with multiple relay depends. Analytical and Matlab simulation results reveal that the proposed technique outperforms Non Optimized technique and exhibit a promising performance.

  11. Power outage estimation for tropical cyclones: improved accuracy with simpler models.

    Science.gov (United States)

    Nateghi, Roshanak; Guikema, Seth; Quiring, Steven M

    2014-06-01

    In this article, we discuss an outage-forecasting model that we have developed. This model uses very few input variables to estimate hurricane-induced outages prior to landfall with great predictive accuracy. We also show the results for a series of simpler models that use only publicly available data and can still estimate outages with reasonable accuracy. The intended users of these models are emergency response planners within power utilities and related government agencies. We developed our models based on the method of random forest, using data from a power distribution system serving two states in the Gulf Coast region of the United States. We also show that estimates of system reliability based on wind speed alone are not sufficient for adequately capturing the reliability of system components. We demonstrate that a multivariate approach can produce more accurate power outage predictions.

  12. Outage Capacity Analysis of TAS/MRC Systems over Arbitrary Nakagami-m Fading Channels

    Science.gov (United States)

    Hung, Chia-Chun; Chiang, Ching-Tai; Lin, Shyh-Neng; Wu, Rong-Ching

    A simple closed-form approximation for the outage capacity of Transmit Antenna Selection/Maximal-Ratio Combining (TAS/MRC) systems over independent and identically distributed (i.i.d) Nakagami-m fading channels is derived while the fading index is a positive integer. When the Nakagami-m fading index is not an integer, the approximate outage capacity is derived as a single infinite series of Gamma function. Computer simulations verify the accuracy of the approximate results.

  13. Determination of breath isoprene allows the identification of the expiratory fraction of the propofol breath signal during real-time propofol breath monitoring.

    Science.gov (United States)

    Hornuss, Cyrill; Dolch, Michael E; Janitza, Silke; Souza, Kimberly; Praun, Siegfried; Apfel, Christian C; Schelling, Gustav

    2013-10-01

    Real-time measurement of propofol in the breath may be used for routine clinical monitoring. However, this requires unequivocal identification of the expiratory phase of the respiratory propofol signal as only expiratory propofol reflects propofol blood concentrations. Determination of CO2 breath concentrations is the current gold standard for the identification of expiratory gas but usually requires additional equipment. Human breath also contains isoprene, a volatile organic compound with low inspiratory breath concentration and an expiratory concentration plateau. We investigated whether breath isoprene could be used similarly to CO2 to identify the expiratory fraction of the propofol breath signal. We investigated real-time breath data obtained from 40 study subjects during routine anesthesia. Propofol, isoprene, and CO2 breath concentrations were determined by a combined ion molecule reaction/electron impact mass spectrometry system. The expiratory propofol signal was identified according to breath CO2 and isoprene concentrations and presented as median of intervals of 30 s duration. Bland-Altman analysis was applied to detect differences (bias) in the expiratory propofol signal extracted by the two identification methods. We investigated propofol signals in a total of 3,590 observation intervals of 30 s duration in the 40 study subjects. In 51.4 % of the intervals (1,844/3,590) both methods extracted the same results for expiratory propofol signal. Overall bias between the two data extraction methods was -0.12 ppb. The lower and the upper limits of the 95 % CI were -0.69 and 0.45 ppb. Determination of isoprene breath concentrations allows the identification of the expiratory propofol signal during real-time breath monitoring.

  14. Synergistic Use of Nighttime Satellite Data, Electric Utility Infrastructure, and Ambient Population to Improve Power Outage Detections in Urban Areas

    Directory of Open Access Journals (Sweden)

    Tony A. Cole

    2017-03-01

    Full Text Available Natural and anthropogenic hazards are frequently responsible for disaster events, leading to damaged physical infrastructure, which can result in loss of electrical power for affected locations. Remotely-sensed, nighttime satellite imagery from the Suomi National Polar-orbiting Partnership (Suomi-NPP Visible Infrared Imaging Radiometer Suite (VIIRS Day/Night Band (DNB can monitor power outages in disaster-affected areas through the identification of missing city lights. When combined with locally-relevant geospatial information, these observations can be used to estimate power outages, defined as geographic locations requiring manual intervention to restore power. In this study, we produced a power outage product based on Suomi-NPP VIIRS DNB observations to estimate power outages following Hurricane Sandy in 2012. This product, combined with known power outage data and ambient population estimates, was then used to predict power outages in a layered, feedforward neural network model. We believe this is the first attempt to synergistically combine such data sources to quantitatively estimate power outages. The VIIRS DNB power outage product was able to identify initial loss of light following Hurricane Sandy, as well as the gradual restoration of electrical power. The neural network model predicted power outages with reasonable spatial accuracy, achieving Pearson coefficients (r between 0.48 and 0.58 across all folds. Our results show promise for producing a continental United States (CONUS- or global-scale power outage monitoring network using satellite imagery and locally-relevant geospatial data.

  15. 基于自适应匹配模型的停电管理系统设计与应用%The design and application of power outage managing system based on data automatic matching model

    Institute of Scientific and Technical Information of China (English)

    熊淦辉; 黎沛坚; 徐俊林; 刘斯烟; 刘柳

    2015-01-01

    文中设计了停电管理系统。该系统通过集成计量自动化系统、营销管理系统、生产系统以及营配数据中心,实现所有专变客户、公变台区停电时间的自动采集,并采用国际标准强化分析方法和停电时间统计自适应匹配模型,实现客户停电时间统计自动化、提高客户停电时间数据统计及时性和准确性。通过在东莞供电局进行的测试运行试点和应用,表明文中设计的客户停电应用管理系统可以使客户停电时间统计准确率提高50%以上。%This thesis designsa power outage managing system. The system integratesmetering automation system、marketing management information system、production system、marketing and distribution data center tocollect power outage time of all special transformer customers and public transformer districtsautomatically . It not just realizes the automatic statistics of customer outage time but also improves effectivenessand accuracyof statistics for customer outage time throughadoptinganalysis method based oninternational standards and the automatic matching model.The trial operation and application in Dongguan power supply bureau show that power outage managing system which the thesis designs can raise the accuracy of statisticsfor customer outage timemore than 50%.

  16. Information from a power transmission line process data bank for an expert system following a network outage. Informationen aus einer Netz-Prozessdatenbank fuer ein Expertensystem zum Netzwiederaufbau

    Energy Technology Data Exchange (ETDEWEB)

    Krost, G.; Rumpel, D. (Duisburg Univ. (Gesamthochschule) (Germany, F.R.). Fachgebiet Elektrische Anlagen und Netze)

    1990-03-01

    An expert system can be of great use in unpredictable and time critical situations. For example following a network outage. It helps find solutions to problems and because of its lucidity be used as a training help for control room personnel. Because of the complexity of the information involved in ascertaining the condition of the network, such an expert system must have access to the transmission line process data bank. (orig.).

  17. Wind turbine outage model based on operation conditions%计及运行工况的风电机组停运模型

    Institute of Scientific and Technical Information of China (English)

    蒋程; 张建华; 刘先正; 于坤山

    2013-01-01

    根据风电机组停运的特点,把其分为电磁系统和机械系统。考虑电网运行工况对风机停运的影响建立了基于电网电压和频率的电磁系统的故障率模型;考虑天气对风机停运的影响建立了基于风速的机械系统的故障率模型,综合上述两方面,得到计及运行工况的风电机组故障率模型。在Matlab中对某1.5 MW风机进行仿真,给出了不同运行工况下风电机组的故障率。此模型能够反映电网运行条件和外界风速对风电机组故障率的影响,能够如实表征风电机组实时运行的安全可靠性水平。%According to the characteristics of outage, the wind turbine is divided into two parts, namely the electromagnetic system and the machinery system. The failure rate model of electromagnetic system based on the grid voltage and frequency is established considering the impact of the grid operating conditions on the wind turbine outage, and the failure rate model of machinery system based on the wind speed is established considering the impact of the weather on the wind turbine outage, then the wind turbine outage rate model based on operating conditions of grid and weather can be obtained. The simulation of 1.5 MW wind turbine is carried out in Matlab, and the outage rate of wind turbine under diffident operation conditions is given. The model can reflect the effect of wind turbine outage rate on the grid operating conditions and external wind speed and can accurately characterize the level of safety and reliability of the wind turbine under real-time operation.

  18. Outage Probability Minimization for Energy Harvesting Cognitive Radio Sensor Networks.

    Science.gov (United States)

    Zhang, Fan; Jing, Tao; Huo, Yan; Jiang, Kaiwei

    2017-01-24

    The incorporation of cognitive radio (CR) capability in wireless sensor networks yields a promising network paradigm known as CR sensor networks (CRSNs), which is able to provide spectrum efficient data communication. However, due to the high energy consumption results from spectrum sensing, as well as subsequent data transmission, the energy supply for the conventional sensor nodes powered by batteries is regarded as a severe bottleneck for sustainable operation. The energy harvesting technique, which gathers energy from the ambient environment, is regarded as a promising solution to perpetually power-up energy-limited devices with a continual source of energy. Therefore, applying the energy harvesting (EH) technique in CRSNs is able to facilitate the self-sustainability of the energy-limited sensors. The primary concern of this study is to design sensing-transmission policies to minimize the long-term outage probability of EH-powered CR sensor nodes. We formulate this problem as an infinite-horizon discounted Markov decision process and propose an ϵ-optimal sensing-transmission (ST) policy through using the value iteration algorithm. ϵ is the error bound between the ST policy and the optimal policy, which can be pre-defined according to the actual need. Moreover, for a special case that the signal-to-noise (SNR) power ratio is sufficiently high, we present an efficient transmission (ET) policy and prove that the ET policy achieves the same performance with the ST policy. Finally, extensive simulations are conducted to evaluate the performance of the proposed policies and the impaction of various network parameters.

  19. Outage Probability Minimization for Energy Harvesting Cognitive Radio Sensor Networks

    Directory of Open Access Journals (Sweden)

    Fan Zhang

    2017-01-01

    Full Text Available The incorporation of cognitive radio (CR capability in wireless sensor networks yields a promising network paradigm known as CR sensor networks (CRSNs, which is able to provide spectrum efficient data communication. However, due to the high energy consumption results from spectrum sensing, as well as subsequent data transmission, the energy supply for the conventional sensor nodes powered by batteries is regarded as a severe bottleneck for sustainable operation. The energy harvesting technique, which gathers energy from the ambient environment, is regarded as a promising solution to perpetually power-up energy-limited devices with a continual source of energy. Therefore, applying the energy harvesting (EH technique in CRSNs is able to facilitate the self-sustainability of the energy-limited sensors. The primary concern of this study is to design sensing-transmission policies to minimize the long-term outage probability of EH-powered CR sensor nodes. We formulate this problem as an infinite-horizon discounted Markov decision process and propose an ϵ-optimal sensing-transmission (ST policy through using the value iteration algorithm. ϵ is the error bound between the ST policy and the optimal policy, which can be pre-defined according to the actual need. Moreover, for a special case that the signal-to-noise (SNR power ratio is sufficiently high, we present an efficient transmission (ET policy and prove that the ET policy achieves the same performance with the ST policy. Finally, extensive simulations are conducted to evaluate the performance of the proposed policies and the impaction of various network parameters.

  20. Study of electrical power facilities and measures for planned outages in Japanese hemodialysis clinics after the Great East Japan Earthquake.

    Science.gov (United States)

    Ishida, Kai; Sawa, Manami; Fujiwara, Kousaku; Hirose, Minoru; Tsuruta, Harukazu; Takeuchi, Akihiro; Ikeda, Noriaki

    2013-02-01

    The Great East Japan Earthquake on 11 March 2011 caused major damage in northeastern Japan. The Kanto region experienced a massive electrical power shortage in the summer of 2011. A questionnaire was submitted to 354 hemodialysis clinics in Kanagawa prefecture and the Tokyo metropolitan area, excluding isolated islands, and 176 responses were analyzed (49.7%). The questions included evaluation of the availability of a private electricity generator, countermeasures in case of a planned outage, awareness of saving electricity, and improvement of safety of medical devices or electrical facilities after the earthquake. Only 12% of the clinics had private electricity generators and many clinics had no plans to introduce this facility. However, 96% of the clinics had established countermeasures to deal with a planned outage. Many clinics planned to provide dialysis on a different day or at a different time. All clinics had tried hard to establish procedures to save electricity in the summer of 2011, and 84% of the clinics had reconsidered and improved the safety of medical devices or electricity facilities after the earthquake. These results show that the awareness of crisis management was greatly improved in the wake of the earthquake.

  1. 基于报文监听和报文仿真验证GOOSE虚端子连接的不停电检修应用%Application of Maintenance Without Power Outage for Verifying GOOSE Virtual Terminal Connection Based on Message Listening and Message Simulation

    Institute of Scientific and Technical Information of China (English)

    王同文; 谢民; 李志坚; 郑文彬

    2016-01-01

    对于一次系统不停电的智能变电站扩建、改建间隔装置,需要接收和发送不停电跨间隔装置过程层GOOSE开关量,不停电运行装置不允许改变过程层GOOSE开关量.为解决不停电检修应用的场景需求,同时避免GOOSE组网光纤的插拔,提出一种基于报文监听和报文仿真验证GOOSE虚端子连接的不停电检修应用方法,即在GOOSE报文接收端监听GOOSE发送端报文,改变监听到的 GOOSE 报文数据集所测试开关量数据的"分"、"合"状态和置位检修品质,然后模拟仿真GOOSE报文发送,最后在接收端通过GOOSE开关量值和检修品质验证GOOSE虚端子连接配置的正确性.%For smart substation expansion and renovation in the condition of primary power system without outage, the bay devices of expansion and renovation must receive and send process layer GOOSE switching value from the device of across multi-bays, and the running device without power outage does not allow changing the process layer GOOSE switching value. In order to solve the scenario requirement of the maintenance application without power outage and at the same time to avoid the plugging and unplugging of the GOOSE networking optical fiber, an application method of maintenance without power outage for verifying GOOSE virtual terminal connection based on message listening and message simulation is proposed, which is to listen message from the GOOSE sending end at the GOOSE message receiving end, and to change the "on" and "off" status of the switching value data which is tested by the monitored GOOSE message data set and the setting maintenance quality. Then GOOSE message sending is simulated. Finally, the validity of the GOOSE virtual terminal connection configuration is verified through GOOSE switching value and maintenance quality at the receiving end

  2. Estimating the Propagation of Interdependent Cascading Outages with Multi-Type Branching Processes

    CERN Document Server

    Qi, Junjian; Sun, Kai

    2015-01-01

    In this paper, the multi-type branching process is applied to describe the statistics of line outages, the load shed, and isolated buses. The offspring mean matrix of the multi-type branching process is estimated by the Expectation Maximization (EM) algorithm and can quantify the extent of outage propagation. The joint distribution of two types of outages is estimated by the multi-type branching process via the Lagrange-Good inversion. The proposed model is tested with data generated by the AC OPA cascading simulations on the IEEE 118-bus system. The largest eigenvalues of the offspring mean matrix indicate that the system is closer to criticality when considering the interdependence of different types of outages. Compared with empirically estimating the joint distribution of the total outages, good estimate is obtained by using the multi-type branching process with a much smaller number of cascades, thus greatly improving the efficiency. It is shown that the multi-type branching process can effectively predi...

  3. Evaluation of power outages in Connecticut during hypothetical future Hurricane Sandy scenarios

    Science.gov (United States)

    Wanik, D. W.; Anagnostou, E. N.; Astitha, M.; Frediani, M. E.; Yang, J.

    2015-12-01

    Reliable electric power is a staple of our modern society.The purpose of this work was to evaluate the occurrence of power outages under more intense, future Hurricane Sandy simulations in Connecticut. In addition, we also evaluated how many crews would be necessary to restore power in 7 days, and how different vegetation scenarios might contribute to a decrease in outages. We trained five pairwise models on each current Sandy runs (2012) as training using the random forest model (each validated using 10-fold cross-validation), and used each future Sandy run as an independent test. We predict that a future Sandy would have 2.5x as many outages as current Sandy, which would require 3.23x as many crews as current Sandy to restore power in 7 days. We also found that increased vegetation management might decrease outages, which has implications for both fair-weather and storm days of all types (i.e. blizzards, thunderstorms, ice storms). Although we have only evaluated outages for electric distribution networks, there are many other types (water supply, wastewater, telecommunications) that would likely benefit from an analysis of this type. In addition, given that we have the weather simulations already processed within our 2-km weather simulation domain, we would like to expand our vulnerability analyses to surrounding utilities in New Jersey, New York, Rhode Island, Massachusetts and New Hampshire to facilitate regional coordination among electric distribution networks.

  4. Improving Hurricane Power Outage Prediction Models Through the Inclusion of Local Environmental Factors.

    Science.gov (United States)

    McRoberts, D Brent; Quiring, Steven M; Guikema, Seth D

    2016-10-25

    Tropical cyclones can significantly damage the electrical power system, so an accurate spatiotemporal forecast of outages prior to landfall can help utilities to optimize the power restoration process. The purpose of this article is to enhance the predictive accuracy of the Spatially Generalized Hurricane Outage Prediction Model (SGHOPM) developed by Guikema et al. (2014). In this version of the SGHOPM, we introduce a new two-step prediction procedure and increase the number of predictor variables. The first model step predicts whether or not outages will occur in each location and the second step predicts the number of outages. The SGHOPM environmental variables of Guikema et al. (2014) were limited to the wind characteristics (speed and duration of strong winds) of the tropical cyclones. This version of the model adds elevation, land cover, soil, precipitation, and vegetation characteristics in each location. Our results demonstrate that the use of a new two-step outage prediction model and the inclusion of these additional environmental variables increase the overall accuracy of the SGHOPM by approximately 17%.

  5. Achievable Outage Rates In Cognitive Radio Networks under Imperfect Spectrum Sensing

    Directory of Open Access Journals (Sweden)

    N. Tafaghodi Khajavi

    2012-06-01

    Full Text Available In this paper, we aim at deriving the outage rates achieved by the primary user due spectrum sensing in a cognitive radio network, that we call sensing-induced primary outage rates. To reach this goal, in the first step, instead of classical spectrum sensing techniques that evaluate sensing performance only based on correct detection of the presence of the primary user’s signal, we propose a modified framework that also takes into account the correct detection of the absence of primary user’s signal for spectrum sensing performance evaluation. In a second step, we derive the information rates achieved by the coexistence of a primary and a cognitive network. In the last step, assuming slow fading sensing channels, we derive the sensing-induced primary outage rates, i.e., outage rates achieved by the primary network in the presence of a CR with imperfect spectrum sensing, characterized by a given miss-detection probability. Numerical results show that the proposed spectrum sensing outperforms conventional spectrum sensing techniques in terms of primary signal outage rates and total achievable throughputs, without any increase in the cognitive radio complexity.

  6. A Short-Term Outage Model of Wind Turbines with Doubly Fed Induction Generators Based on Supervisory Control and Data Acquisition Data

    Directory of Open Access Journals (Sweden)

    Peng Sun

    2016-10-01

    Full Text Available This paper presents a short-term wind turbine (WT outage model based on the data collected from a wind farm supervisory control and data acquisition (SCADA system. Neural networks (NNs are used to establish prediction models of the WT condition parameters that are dependent on environmental conditions such as ambient temperature and wind speed. The prediction error distributions are discussed and used to calculate probabilities of the operation of protection relays (POPRs that were caused by the threshold exceedance of the environmentally sensitive parameters. The POPRs for other condition parameters are based on the setting time of the operation of protection relays. The union probability method is used to integrate the probabilities of operation of each protection relay to predict the WT short term outage probability. The proposed method has been used for real 1.5 MW WTs with doubly fed induction generators (DFIGs. The results show that the proposed method is more effective in WT outage probability prediction than traditional methods.

  7. [Responding to patients with home mechanical ventilation after the Great East Japan Earthquake and during the planned power outages. How should we be prepared for a future disaster ?].

    Science.gov (United States)

    Takechi, Yukako

    2011-12-01

    The unprecedented earthquake(magnitude-9 in the Japanese seismic intensity scale)hit off the east coast of Japan on March 11, 2011. Consequently, there were planned power outages in the area nearby Tokyo to avoid massive blackouts caused by a stoppage of Fukushima nuclear plants.Our clinic located in Kawasaki city was also hit by the earthquake(magnitude- 5).During the period of two months(March and April 2011), we had a total of 52 patients with home respiratory care (5-TPPV, 11-NPPV and 36-HOT)at that time.Two out of three 24 hour-TPPV users had no external battery.After the earthquake, there was a 7-hour electricity failure in some areas, and a patient with ASV(adaptive servo ventilator)was living there.Moreover, 3-hour/day power outages were carried out from March 14 to March 28, affecting people's everyday lives. However, the patient had no harmful influences from the power failure because a ventilation company lent us an external battery(4-9 hour life capacity)for the patients, and we were able to avoid an emergency situation caused by the power failure.In conclusion, we ought to be prepared for patients with home mechanical ventilation in the future toward unforeseen large scale power outages.

  8. Plasma Outages in Pulsed, High-Power RF Hydrogen Ion Sources

    Science.gov (United States)

    Stockli, Martin; Han, Baoxi; Murray, Syd; Pennisi, Terry; Piller, Chip; Santana, Manuel; Welton, Robert

    2011-04-01

    Pulsed, high-power RF ion sources are needed to produce copious amounts of negative H-ions for high-power accelerators with charge-changing injection schemes. When increasing the RF power, the plasma inductance changes the RF resonance, which drifts away from the low-power resonance. When the RF circuit is tuned to maximize the (pulsed) plasma power, the (off-resonance) power at the beginning of the pulse is reduced. If the induced electric fields fall below the breakdown strength of the hydrogen gas, the plasma fails to develop. This can be avoided with a compromise tune and/or by increasing the inductance of the resonant circuit. However, the breakdown strength of the hydrogen gas increases with time due to the gradual decrease of the electron-rich plasma impurities, which causes plasma outages after weeks of reliable operation. In this paper we discuss the success of different mitigations that were tested and implemented to overcome this fundamental problem of pulsed, high-power RF hydrogen ion sources.

  9. Outage Performance of Decode-and-Forward in Two-Way Relaying with Outdated CSI

    KAUST Repository

    Hyadi, Amal

    2015-01-07

    In this paper, we analyze the outage behavior of decode-and-forward relaying in the context of selective two-way cooperative systems. First, a new relay selection metric is proposed to take into consideration both transmission rates and instantaneous link conditions between cooperating nodes. Afterwards, the outage probability of the proposed system is derived for Nakagami-m fading channels in the case when perfect channel state information is available and then extended to the more realistic scenario where the available channel state information (CSI) is outdated due to fast fading. New expressions for the outage probability are obtained, and the impact of imperfect CSI on the performance is evaluated. Illustrative numerical results, Monte Carlo simulations, and comparisons with similar approaches are presented to assess the accuracy of our analytical derivations and confirm the performance gain of the proposed scheme.

  10. A Simple Scheme for Improved Performance of Fixed Outage Rate Cellular System

    Directory of Open Access Journals (Sweden)

    Hussein M.A. Basi

    2004-01-01

    Full Text Available The traffic characteristic of mobile cellular systems is rather distinct from that of a fixed telephone network. However the system planning and design are still carried out with the tools of conventional traffic theory. In the recent days much work is being done in the performance evaluation of mobile or cellular communication systems in order to develop a system with greater efficiency. The useful parameters to estimate the performance of the system are voice quality, frequency spectrum efficiency and Grade of Service (GOS. The grade of service will be affected due to outage of channels. In this study, a new scheme is proposed to reduce lost calls due to channel outage in the fixed rate outage cellular system. In this proposed scheme the call will never dropped but may be delayed. The system performance is evaluated for different conditions and the results are discussed.

  11. Cognitive multiple-antenna network in outage-restricted primary system

    DEFF Research Database (Denmark)

    Maham, Behrouz; Popovski, Petar

    2013-01-01

    -form asymptotic formula for the outage probability is derived, which shows that the primary receiver achieves full spatial diversity under given interference from the secondary user. Next, the optimum transmit power in the secondary system is investigated for maximizing the ergodic capacity when...... interference from the downlink MISO cognitive radio, also called secondary system. We derive exact expressions for outage probability of the primary user under Rayleigh fading, when the primary system is exposed to interference from a secondary base station. Moreover, in high-SNR scenario, a closed...... there is an outage constraint at the primary system, and a simple solution is proposed. Finally, the analytical results are confirmed by simulations, in which we analyze the impact of different parameters, such as the number of antennas and the amount of the interference on the system performance; these could...

  12. Coordinated Beamforming for Multiuser MISO Interference Channel under Rate Outage Constraints

    CERN Document Server

    Li, Wei-Chiang; Lin, Che; Chi, Chong-Yung

    2011-01-01

    This paper studies the coordinated beamforming design problem for the multiple-input single-output (MISO) interference channel, assuming only channel distribution information (CDI) at the transmitters. For a given requirement on the rate outage probability for receivers, we aim to maximize the system utility (e.g., the weighted sum rate, weighted proportional fairness rate, and the weighed harmonic mean rate) subject to the rate outage constraints and individual power constraints. The outage constraints, however, lead to a complicated, nonconvex structure for the considered beamforming design problem and make the optimization problem difficult to handle. While this nonconvex optimization problem can be solved in an exhaustive search manner, this brute-force approach is only feasible when the number of transmitter-receiver pairs is small. For a system with a large number of transmitter-receiver pairs, computationally efficient alternatives are necessary. The focus of this paper is hence on the design of such e...

  13. Outage performance of reactive cooperation in Nakagami-m fading channels

    KAUST Repository

    Benjillali, Mustapha

    2010-06-01

    In this paper, we investigate the outage performance of Decode-and-Forward with reactive relaying in dual-hop cooperetive Nakagaml-m fading links. The destination, based on the umque knowledge of local second hop channel state information, selects the best relay to increase the chances of cooperation when the direct link is also available. After deriving the exact distribution of the variables of interest, the outage probability of the system - with and without the direct link - is obtained in closed-form, and the ε-outage capacity is derived in the particular c.se wh.ere the channel model is reduced to a Rayleigh fading. Simulation results confirm the accuracy of our analysis for a large selection of system and fading parameters.

  14. Outage performance of Decode-and-Forward partial selection in Nakagami-m fading channels

    KAUST Repository

    Benjillali, Mustapha

    2010-01-01

    In this paper, we investigate the outage performance of Decode-and-Forward with partial selection relaying in dualhop cooperative Nakagami-m fading links. The source, based on the unique knowledge of local first hop channel state information, selects the best relay to increase the chances of successful decoding and hence the possibility of cooperation when the direct link is also available. After deriving the exact distribution of the sum of two gamma variates with the same shape parameter, the outage probability of the system-with and without the direct link-is obtained in closed-form. We also derive the ε-outage capacity in different particular cases, and the obtained results- when the channel model is reduced to a Rayleigh fading-are either new or correspond to those previously obtained in other works. Simulation results confirm the accuracy of our analysis for a large selection of system and fading parameters. © 2009 IEEE.

  15. Integrated head area design of KNGR to reduce refueling outage duration

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Woo Tae; Park, Chi Yong; Kim, In Hwan; Kim, Dae Woong [Korea Electric Power Research Institute, Taejon (Korea, Republic of)

    1997-12-31

    In the design of KNGR (Korea Next Generation Reactor), we believe that economy is one of the most important factors to be considered. Thus, we reviewed and evaluated the consequences of designing the head area into an integrated package from an economical point of view. The refueling outage durations of the nuclear power plants currently in operation in Korea, some having and others not having integrated head package, are compared. This paper discusses the characteristics of head area design and the critical design issues of KNGR head area to evaluate the effect of the head area characteristics on the outage duration. 8 refs., 4 figs. (Author)

  16. ANALYSIS OF FEEDERS OUTAGES ON THE DISTRIBUTION SYSTEM OF ZARIA TOWN

    OpenAIRE

    Adegboye, B A

    2010-01-01

    The paper is aimed at analysing the outages on the feeders of the distribution system, in Zaria Town, Kaduna State, Nigeria. The 11 kV feeders are the NNPC feeder, Gaskiya feeder, Sabon Gari feeder, NTC/RLY feeder and the Canteen feeder. The 33 kV feeders, on the other hand, are the Shika feeder, Giwa/Makarfi feeder and the Soba feeder. The analysis is based on the daily outage data collected for a period of about one year (April, 2003 to April, 2004 – thirteen months). From these data, the t...

  17. Outage probability analysis of wireless sensor networks in the presence of channel fading and spatial correlation

    KAUST Repository

    Al-Murad, Tamim M.

    2011-07-01

    Evaluating the reliability of wireless sensor networks is becoming more important as theses networks are being used in crucial applications. The outage probability defined as the probability that the error in the system exceeds a maximum acceptable threshold has recently been used as a measure of the reliability of such systems. In this work we find the outage probability of wireless sensor network in different scenarios of distributed sensing where sensors\\' readings are affected by spatial correlation and in the presence of channel fading. © 2011 IEEE.

  18. Operational readiness verification, phase 1: A study on safety during outage and restart of nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Hollnagel, E. [Linkoeping Univ. (Sweden). Dept. of Computer and Information Science; Gauthereau, V. [Linkoeping Univ. (Sweden). Dept. of Industrial Engineering

    2001-06-01

    proposed to continue the study by looking more closely at the differences between three levels, or types, of tests: object test, system test and (safety) function test. This should aim to analyse the different steps of testing in order to understand the non-trivial relations between tests and safety. The study should take place at a single NPP during partial/sub-outages, since these periods allow empirical work to be conducted in an appropriate environment with better accessibility to technical staff than during full outage period.

  19. Reverse Link Outage Probabilities of Multicarrier CDMA Systems with Beamforming in the Presence of Carrier Frequency Offset

    Directory of Open Access Journals (Sweden)

    Hu Xiaoyu

    2008-01-01

    Full Text Available The outage probability of reverse link multicarrier (MC code-division multiple access (CDMA systems with beamforming in the presence of carrier frequency offset (CFO is studied. A conventional uniform linear array (ULA beamformer is utilized. An independent Nakagami fading channel is assumed for each subcarrier of all users. The outage probability is first investigated under a scenario where perfect beamforming is assumed. A closed form expression of the outage probability is derived. The impact of different types of beamforming impairments on the outage probability is then evaluated, including direction-of-arrival (DOA estimation errors, angle spreads, and mutual couplings. Numerical results show that the outage probability improves significantly as the number of antenna elements increases. The effect of CFO on the outage probability is reduced significantly when the beamforming technique is employed. Also, it is seen that small beamforming impairments (DOA estimation errors and angle spreads only affect the outage probability very slightly, and the mutual coupling between adjacent antenna elements does not affect the outage probability noticeably.

  20. 10 CFR 501.191 - Use of natural gas or petroleum for certain unanticipated equipment outages and emergencies...

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Use of natural gas or petroleum for certain unanticipated... Natural Gas or Petroleum for Emergency and Unanticipated Equipment Outage Purposes § 501.191 Use of natural gas or petroleum for certain unanticipated equipment outages and emergencies defined in...

  1. Reverse Link Outage Probabilities of Multicarrier CDMA Systems with Beamforming in the Presence of Carrier Frequency Offset

    Directory of Open Access Journals (Sweden)

    Xiaoyu Hu

    2007-11-01

    Full Text Available The outage probability of reverse link multicarrier (MC code-division multiple access (CDMA systems with beamforming in the presence of carrier frequency offset (CFO is studied. A conventional uniform linear array (ULA beamformer is utilized. An independent Nakagami fading channel is assumed for each subcarrier of all users. The outage probability is first investigated under a scenario where perfect beamforming is assumed. A closed form expression of the outage probability is derived. The impact of different types of beamforming impairments on the outage probability is then evaluated, including direction-of-arrival (DOA estimation errors, angle spreads, and mutual couplings. Numerical results show that the outage probability improves significantly as the number of antenna elements increases. The effect of CFO on the outage probability is reduced significantly when the beamforming technique is employed. Also, it is seen that small beamforming impairments (DOA estimation errors and angle spreads only affect the outage probability very slightly, and the mutual coupling between adjacent antenna elements does not affect the outage probability noticeably.

  2. The cost of power outages in the business and public sectors in Israel: Revealed preference vs. subjective evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Beenstock, M.; Goldin, E.; Haitovsky, Y. [Hebrew Univ. of Jerusalem, Mount Scopus (Israel)

    1997-05-01

    The economic cost of power outages is a central parameter in the cost-benefit analysis of electric power reliability and the design of electric power systems. The authors present a new methodology for estimating the cost of power outages in the business and public sections and illustrate with data for Israel. The methodology is based on the principle of revealed preference, the cost of an outage may be inferred from the actions taken by consumers to mitigate losses induced by unsupplied electricity. If outages impose costs on businesses, managers are likely to invest in back-up power to mitigate the losses that are incurred when electricity is not supplied. Investment in back-up generators may then be used to impute the mitigated and unmitigated damage from outages. 12 refs., 3 figs., 7 tabs.

  3. Wearable Devices for Sports: New Integrated Technologies Allow Coaches, Physicians, and Trainers to Better Understand the Physical Demands of Athletes in Real time.

    Science.gov (United States)

    Seshadri, Dhruv R; Drummond, Colin; Craker, John; Rowbottom, James R; Voos, James E

    2017-01-01

    Elite-level athletes and professional sports teams are continually searching for opportunities to improve athletic performance and gain a competitive advantage on the field. Advances in technology have provided new avenues to maximize player health and safety. Over the last decade, time?motion analysis systems, such as video recording and computer digitization, have been used to measure human locomotion and improve sports performance. While these techniques were state of the art at the time, their usefulness is inhibited by the questionable validity of the acquired data, the labor-intensive nature of collecting data with manual hand-notation techniques, and their inability to track athlete position, movement, displacement, and velocity.

  4. Secrecy outage analysis of multi-user multi-eavesdropper cellular networks in the face of cochannel interference

    Directory of Open Access Journals (Sweden)

    Yuan Jiang

    2015-02-01

    Full Text Available This paper studies the physical-layer security of a multi-user multi-eavesdropper cellular network, which is composed of multiple users communicating with a base station while the eavesdroppers may intercept the communications from users to the base station (BS. The cellular network is a time-slotted system with simultaneously transmission, in each time slot, a single user is scheduled to transmit messages to BS while the remaining users opportunistically receive information. Considering multiple users available in the cellular network, we present three multi-user scheduling schemes, namely the round-robin scheduling scheme as well as the suboptimal and optimal user scheduling schemes to improve the security of communication (from users to BS against eavesdropping attacks. We only need to assume that the channel state information (CSI of the main link spanning from users to BS is known in the suboptimal scheduling. On the contrary, the optimal scheduling is designed by assuming that the CSI of the main link and wiretap link (spanning from users to the eavesdropper are available. We further carry out secrecy diversity analysis and show that the round-robin always achieves only one diversity order, whereas the suboptimal and optimal user scheduling schemes achieve the full diversity. In addition, numerical results illustrate that the optimal scheduling performs the best and the round-robin has the worst performance in terms of the secrecy outage probability. Last, as the number of users increases, the secrecy outage probabilities of the suboptimal and optimal scheduling schemes decrease significantly.

  5. Refueling outage services in Spanish Nuclear Power Plants; Servicios en recargas de centrales nucleares

    Energy Technology Data Exchange (ETDEWEB)

    Landete, J. L.; Soto, M.; Nunuez, A.

    2007-07-01

    DOMINGUIS Group, through its 75 years of business development, has positioned as the Spanish leader Group in Services for the Nuclear Energy and Petrochemical Sectors. In this article, we present the most significant services summary that, through the companies that constitute DOMINGUIS Group, we have developed in Refueling Outage in Spanish Nuclear Power Plants. (Author)

  6. The effect of power outages on in-facility mortality in healthcare facilities: Evidence from Ghana.

    Science.gov (United States)

    Apenteng, Bettye A; Opoku, Samuel T; Ansong, Daniel; Akowuah, Emmanuel A; Afriyie-Gyawu, Evans

    2016-08-17

    The World Bank estimates that at least 25 countries in the Sub-Saharan region of Africa experience chronic power outages. However, the implications of power shortages are often discussed within the context of industrial and economic disruptions, with little attention given to the health impact. Using a nationally representative data of healthcare facilities from the 2012 Ghana Access, Bottlenecks, Cost and Equity (ABCE) Health Facility Survey, this study aims to assess the impact of power outages on in-healthcare facility mortality in Ghana, a country that has experienced worsening energy crises in the last few decades. Findings revealed a positive association between the frequency of power outages and in-facility mortality, with the risk for mortality estimated to increase by 43% for each day the power was out for over 2 h. Further, when compared to an urban healthcare facility experiencing the same frequency of power outages, the risk of mortality was found to be lower in the rural facility. These findings call for a concerted effort among all stakeholders to ensure the availability of consistent power supply in healthcare facilities, in order to provide the necessary environment for the successful provision of healthcare for the citizens of Ghana.

  7. Induction of an LH surge and ovulation by buserelin (as Receptal) allows breeding of weaned sows with a single fixed-time insemination

    NARCIS (Netherlands)

    Driancourt, M.A.; Cox, P.; Rubion, S.; Harnois-Milon, G.; Kemp, B.; Soede, N.M.

    2013-01-01

    The aim of this study was to demonstrate successful breeding of sows with a single fixed-time insemination following ovulation induction by buserelin, a GnRH analogue. In a first step, the optimal dose of buserelin (6, 10, or 16 µg) injected at 77 hours after weaning was determined in weaned sows (N

  8. 5'-MGB probes allow rapid identification of methanogens and sulfate reducers in cold marine sediments by real-time PCR and melting curve analysis.

    Science.gov (United States)

    Afonina, Irina; Savvichev, Alexander; Ankoudinova, Irina; Mahoney, Walt

    2009-09-01

    The analysis of microorganism communities in uncultured environmental samples requires laborious and cumbersome techniques such as denaturing gradient gel electrophoresis of amplicons generated with 16S rRNA generic primers with subsequent fragment sequencing. We have developed a simple method for genus identification of methanogen archaea and sulfate-reducing bacteria based on a real-time PCR hybridization probe melting curve analysis. The method takes advantage of a recent explosion of microorganism sequencing data conveniently packaged in the Ribosomal Database Project. Specificity of detection is based on a genus-specific real-time PCR fluorescent 5'-MGB-probe melt. As the probes are designed to have destabilizing mismatches with undesired genera, only samples with a proper melting temperature are called positive.

  9. Conventional and real-time PCRs for detection of Erwinia piriflorinigrans allow its distinction from the fire blight pathogen, Erwinia amylovora.

    Science.gov (United States)

    Barbé, Silvia; Bertolini, Edson; Roselló, Montserrat; Llop, Pablo; López, María M

    2014-04-01

    Erwinia piriflorinigrans is a new pathogenic species of the bacterial genus Erwinia that has been described recently in Spain. Accurate detection and identification of E. piriflorinigrans are challenging because its symptoms on pear blossoms are similar to those caused by Erwinia amylovora, the causal agent of fire blight. Moreover, these two species share phenotypic and molecular characteristics. Two specific and sensitive conventional and real-time PCR protocols were developed to identify and detect E. piriflorinigrans and to differentiate it from E. amylovora and other species of this genus. These protocols were based on sequences from plasmid pEPIR37, which is present in all strains of E. piriflorinigrans analyzed. After the stability of the plasmid was demonstrated, the specificities of the protocols were confirmed by the amplification of all E. piriflorinigrans strains tested, whereas 304 closely related pathogenic and nonpathogenic Erwinia strains and microbiota from pear trees were not amplified. In sensitivity assays, 10(3) cells/ml extract were detected in spiked plant material by conventional or real-time PCR, and 10(2) cells/ml were detected in DNA extracted from spiked plant material by real-time PCR. The protocols developed here succeeded in detecting E. piriflorinigrans in 102 out of 564 symptomatic and asymptomatic naturally infected pear samples (flowers, cortex stem tissue, leaves, shoots, and fruitlets), in necrotic Pyracantha sp. blossoms, and in necrotic pear and apple tissues infected with both E. amylovora and E. piriflorinigrans. Therefore, these new tools can be used in epidemiological studies that will enhance our understanding of the life cycle of E. piriflorinigrans in different hosts and plant tissues and its interaction with E. amylovora.

  10. Application and Fast Simulation of Cascading Outage Based on Genetic Algorithms%基于遗传算法的连锁故障快速模拟及应用

    Institute of Scientific and Technical Information of China (English)

    程林; 刘满君; 何剑

    2015-01-01

    At present,China has finally entered a fast developing period characterized by trans-regional mutual supply,ultra high voltage(UHV),extra high voltage(EHV)and AC-DC hybrid transmission.However,this has led to the staggering rate of power electric system complexity that increases the risk of cascading outage and blackout.A power system cascading outage simulation algorithm is proposed based on genetic algorithms.In searching for the paths with great risk of cascading outage, the algorithm takes the real-time operation environment into consideration while simulating the process of biological evolution based on natural selection.Finally probable cascading outage paths caused by different initial states are found.A case study shows that this algorithm is able to quickly simulate cascading outage,locate critical points of the system and issue alarm of outage,while providing further support to dispatchers in stopping cascading outage in its initial state.%目前,中国电网已进入跨大区互联,超、特高压交直流混合输电的快速发展时期,电网复杂程度急剧增加,发生连锁故障以致引发大面积停电事故的风险逐渐增加。文中在现有连锁故障算法研究的基础上,提出一种基于遗传算法的连锁故障快速模拟算法。该算法应用遗传算法理论,考虑系统运行条件影响,通过模拟基于自然选择的生物进化过程,搜索电力系统连锁故障风险较大的路径,模拟系统在不同初始状态下的可能连锁故障。实际算例表明,该算法可快速模拟电力系统连锁故障,发现系统薄弱环节并发出故障预警,从而进一步为连锁故障阻断对策制定及电网调度提供辅助支持。

  11. Optical parametric oscillator-based photoacoustic detection of CO2 at 4.23 μm allows real-time monitoring of the respiration of small insects

    Science.gov (United States)

    van Herpen, M. M. J. W.; Ngai, A. K. Y.; Bisson, S. E.; Hackstein, J. H. P.; Woltering, E. J.; Harren, F. J. M.

    2006-03-01

    A continuous wave, single frequency and continuously tunable optical parametric oscillator is used in combination with photoacoustic spectroscopy to detect trace emissions of CO2 from insects under atmospheric conditions. The optical parametric oscillator (OPO) contains a periodically poled lithium niobate crystal and is tunable over the 3.9 to 4.8 μm infrared wavelength region. With the strong rotational-vibrational absorption band of CO2 at 4.23 μm, it is possible to detect CO2 down to 7 parts per billion volume using 20 mW of the OPO beam. This detection sensitivity was achieved by adding 4% of SF6 gas to the atmospheric gas mixture to overcome the slow vibrational relaxation of the excited CO2 levels. The usefulness of this system is demonstrated by real-time measuring of the fluctuations of the CO2 concentration in the breath of a single ant (Lasius niger) and individual fruit flies (Drosophila melanogaster).

  12. Does your domestic photovoltaic energy system survive grid outages?

    OpenAIRE

    Jongerden, Marijn R.; Jannik Hüls; Anne Remke; Haverkort, Boudewijn R.

    2016-01-01

    Domestic renewable energy systems, including photovoltaic energy generation, as well as local storage, are becoming increasingly popular and economically feasible, but do come with a wide range of options. Hence, it can be difficult to match their specification to specific customer’s needs. Next to the usage-specific demand profiles and location-specific production profiles, local energy storage through the use of batteries is becoming increasingly important, since it allows one to balance va...

  13. Outage Probability of Interference-limited Switch and Stay Diversity System over Gamma Shadowed Nakagami-m Fading Channels

    Science.gov (United States)

    Djordjevic, Goran T.; Antic, Dragan

    2013-12-01

    In this paper, the outage performance of a dual-branch switch and stay combining (SSC) diversity receiver operating over composite multipath Nakagami-m fading/gamma shadowing channels in the presence of a co-channel interference is determined. For a single channel composite fading environment, we derive the new analytical expressions for the probability density function and cumulative distribution function of the instantaneous signal-to-interference (SIR) ratio that can be used as alternatives to the previously published results. In the case of non-identically distributed and power unbalanced SSC branches with arbitrary fading parameters, the outage performance is determined. The choice of optimal switching threshold in minimum outage probability sense is discussed. The results show the outage probability dependence on simultaneous effects of the SIR unbalancing, as well as multipath fading and shadowing severities. The analytical results are confirmed by Monte Carlo simulations.

  14. Outage Analysis of Ultra-Wideband System in Lognormal Multipath Fading and Square-Shaped Cellular Configurations

    Directory of Open Access Journals (Sweden)

    Pirinen Pekka

    2006-01-01

    Full Text Available Generic ultra-wideband (UWB spread-spectrum system performance is evaluated in centralized and distributed spatial topologies comprising square-shaped indoor cells. Statistical distributions for link distances in single-cell and multicell configurations are derived. Cochannel-interference-induced outage probability is used as a performance measure. The probability of outage varies depending on the spatial distribution statistics of users (link distances, propagation characteristics, user activities, and receiver settings. Lognormal fading in each channel path is incorporated in the model, where power sums of multiple lognormal signal components are approximated by a Fenton-Wilkinson approach. Outage performance of different spatial configurations is outlined numerically. Numerical results show the strong dependence of outage probability on the link distance distributions, number of rake fingers, and path losses.

  15. On the Outage Performance of Full-Duplex Selective Decode-and-Forward Relaying

    KAUST Repository

    Khafagy, Mohammad Galal

    2013-02-25

    We evaluate the outage performance in a three-terminal full-duplex relay channel that adopts a selective decode-and-forward protocol, taking relay self-interference into account. Previous work focused on coverage extension scenarios where direct source-destination transmissions are neglected or considered as interference. In this work, we account for the relay self-interference, and exploit the cooperative diversity offered by the independently fading source/relay message replicas that arrive at the destination. We present an approximate, yet accurate, closed-form expression for the end-to-end outage probability that captures their joint effect. With the derived expression in hand, we propose a relay transmit power optimization scheme that only requires the relay knowledge of channel statistics. Finally, we corroborate our analysis with simulations.

  16. Outage and Capacity Performance Evaluation of Distributed MIMO Systems over a Composite Fading Channel

    Directory of Open Access Journals (Sweden)

    Wenjie Peng

    2014-01-01

    Full Text Available The exact closed-form expressions regarding the outage probability and capacity of distributed MIMO (DMIMO systems over a composite fading channel are derived. This is achieved firstly by using a lognormal approximation to a gamma-lognormal distribution when a mobile station (MS in the cell is in a fixed position, and the so-called maximum ratio transmission/selected combining (MRT-SC and selected transmission/maximum ratio combining (ST-MRC schemes are adopted in uplink and downlink, respectively. Then, based on a newly proposed nonuniform MS cell distribution model, which is more consistent with the MS cell hotspot distribution in an actual communication environment, the average outage probability and capacity formulas are further derived. Finally, the accuracy of the approximation method and the rationality of the corresponding theoretical analysis regarding the system performance are proven and illustrated by computer simulations.

  17. Method for estimating power outages and restoration during natural and man-made events

    Energy Technology Data Exchange (ETDEWEB)

    Omitaomu, Olufemi A.; Fernandez, Steven J.

    2016-01-05

    A method of modeling electric supply and demand with a data processor in combination with a recordable medium, and for estimating spatial distribution of electric power outages and affected populations. A geographic area is divided into cells to form a matrix. Within the matrix, supply cells are identified as containing electric substations and demand cells are identified as including electricity customers. Demand cells of the matrix are associated with the supply cells as a function of the capacity of each of the supply cells and the proximity and/or electricity demand of each of the demand cells. The method includes estimating a power outage by applying disaster event prediction information to the matrix, and estimating power restoration using the supply and demand cell information of the matrix and standardized and historical restoration information.

  18. Cognitive Multiple Access Network with Outage Margin in the Primary System

    DEFF Research Database (Denmark)

    Maham, Behrouz; Popovski, Petar; Zhou, Xiangyun;

    2011-01-01

    system is exposed to interference from secondary users. Moreover, approximated formulas and tight lower and upper bounds for the ergodic sum-rate capacity of the secondary network are found. Next, the power allocation is investigated in the secondary system for maximizing the sum-rate under an outage....... We derive the achievable rate in the secondary system when OIC is used. This scheme has a practical significance, since it enables rate adaptation without requiring any action from the primary system. The exact expressions for outage probability of the primary user are derived, when the primary...... constraint at the primary system. We formulate the power optimization problem in various scenarios depending on the availability of channel state information and the type of power constraints, and propose a set of simple solutions. Finally, the analytical results are confirmed by simulations, indicating both...

  19. Cognitive Multiple Access Network with Outage Margin in the Primary System

    CERN Document Server

    Maham, Behrouz; Zhou, Xiangyun; Hjørungnes, Are

    2011-01-01

    This paper investigates the problem of spectrally efficient operation of a multiuser uplink cognitive radio system in the presence of a single primary link. The secondary system applies opportunistic interference cancelation (OIC) and decode the primary signal when such an opportunity is created. We derive the achievable rate in the secondary system when OIC is used. This scheme has a practical significance, since it enables rate adaptation without requiring any action from the primary system. The \\emph{exact} expressions for outage probability of the primary user are derived, when the primary system is exposed to interference from secondary users. Moreover, approximated formulas and tight lower and upper bounds for the ergodic sum-rate capacity of the secondary network are found. Next, the power allocation is investigated in the secondary system for maximizing the sum-rate under an outage constraint at the primary system. We formulate the power optimization problem in various scenarios depending on the avail...

  20. Recent performance of and plasma outage studies with the SNS H- source

    Science.gov (United States)

    Stockli, M. P.; Han, B.; Murray, S. N.; Pennisi, T. R.; Piller, C.; Santana, M.; Welton, R.

    2016-02-01

    Spallation Neutron Source ramps to higher power levels that can be sustained with high availability. The goal is 1.4 MW despite a compromised radio frequency quadrupole (RFQ), which requires higher radio frequency power than design levels to approach the nominal beam transmission. Unfortunately at higher power the RFQ often loses its thermal stability, a problem apparently enhanced by beam losses and high influxes of hydrogen. Delivering as much H- beam as possible with the least amount of hydrogen led to plasma outages. The root cause is the dense 1-ms long ˜55-kW 2-MHz plasma pulses reflecting ˜90% of the continuous ˜300 W, 13-MHz power, which was mitigated with a 4-ms filter for the reflected power signal and an outage resistant, slightly detuned 13-MHz match. Lowering the H2 gas also increased the H- beam current to ˜55 mA and increased the RFQ transmission by ˜7% (relative).

  1. A RLS-SVM Aided Fusion Methodology for INS during GPS Outages.

    Science.gov (United States)

    Yao, Yiqing; Xu, Xiaosu

    2017-02-24

    In order to maintain a relatively high accuracy of navigation performance during global positioning system (GPS) outages, a novel robust least squares support vector machine (LS-SVM)-aided fusion methodology is explored to provide the pseudo-GPS position information for the inertial navigation system (INS). The relationship between the yaw, specific force, velocity, and the position increment is modeled. Rather than share the same weight in the traditional LS-SVM, the proposed algorithm allocates various weights for different data, which makes the system immune to the outliers. Field test data was collected to evaluate the proposed algorithm. The comparison results indicate that the proposed algorithm can effectively provide position corrections for standalone INS during the 300 s GPS outage, which outperforms the traditional LS-SVM method. Historical information is also involved to better represent the vehicle dynamics.

  2. A RLS-SVM Aided Fusion Methodology for INS during GPS Outages

    Directory of Open Access Journals (Sweden)

    Yiqing Yao

    2017-02-01

    Full Text Available In order to maintain a relatively high accuracy of navigation performance during global positioning system (GPS outages, a novel robust least squares support vector machine (LS-SVM-aided fusion methodology is explored to provide the pseudo-GPS position information for the inertial navigation system (INS. The relationship between the yaw, specific force, velocity, and the position increment is modeled. Rather than share the same weight in the traditional LS-SVM, the proposed algorithm allocates various weights for different data, which makes the system immune to the outliers. Field test data was collected to evaluate the proposed algorithm. The comparison results indicate that the proposed algorithm can effectively provide position corrections for standalone INS during the 300 s GPS outage, which outperforms the traditional LS-SVM method. Historical information is also involved to better represent the vehicle dynamics.

  3. On the outage capacity of the block fading channel at low-power regime

    KAUST Repository

    Rezki, Zouheir

    2014-06-01

    Outage performance of the M-block fading with additive white Gaussian noise (BF-AWGN) is investigated at low-power regime. We consider delay-constrained constant-rate communications with perfect channel state information (CSI) at both the transmitter and the receiver (CSI-TR), under a short-term power constraint. We show that selection diversity that allocates all the power to the strongest block is asymptotically optimal. Then, we provide a simple characterization of the outage probability in the regime of interest. We quantify the reward due to CSI-TR over the constant-rate constant-power scheme and show that this reward increases with the delay constraint. For instance, for Rayleigh fading, we find that a power gain up to 4.3 dB is achievable. © 2014 IEEE.

  4. Exact Outage Performance Analysis of Multiuser Multi-relay Spectrum Sharing Cognitive Networks

    Directory of Open Access Journals (Sweden)

    T. Zhang

    2015-04-01

    Full Text Available In this paper, we investigate the outage performance of dual-hop multiuser multi-relay cognitive radio networks under spectrum sharing constraints. Using an efficient relay-destination selection scheme, the exact and asymptotic closed-form expressions for the outage probability are derived. From these expressions it is indicated that the achieved diversity order is only determined by the number of secondary user (SU relays and destinations, and equals to M+N (where M and N are the number of destination nodes and relay nodes, respectively. Further, we find that the coding gain of the SU network will be affected by the interference threshold $bar I$ at the primary user (PU receiver. Specifically, as the increases of the interference threshold, the coding gain of the considered network approaches to that of the multiuser multi-relay system in the non-cognitive network. Finally, our study is corroborated by representative numerical examples.

  5. Recent Performance of and Plasma Outage Studies with the SNS H- Source

    Energy Technology Data Exchange (ETDEWEB)

    Stockli, Martin P [ORNL; Han, Baoxi [ORNL; Murray Jr, S N [ORNL; Pennisi, Terry R [ORNL; Piller, Chip [ORNL; Santana, Manuel [ORNL; Welton, Robert F [ORNL

    2016-01-01

    SNS ramps to higher power levels that can be sustained with high availability. The goal is 1.4 MW despite a compromised RFQ, which requires higher RF power than design levels to approach the nominal beam transmission. Unfortunately at higher power the RFQ often loses its thermal stability, a problem apparently enhanced by beam losses and high influxes of hydrogen. Delivering as much H- beam as possible with the least amount of hydrogen led to plasma outages. The root cause is the dense 1-ms long ~55-kW 2-MHz plasma pulses reflecting ~90% of the continuous ~300W, 13-MHz power, which was mitigated with a 4-ms filter for the reflected power signal and an outage resistant, slightly-detuned 13-MHz match. Lowering the H2 also increased the H- beam current to ~55 mA, and increased the transmission by ~7%.

  6. Outage Performance of Hybrid FSO/RF System with Low-Complexity Power Adaptation

    KAUST Repository

    Rakia, Tamer

    2016-02-26

    Hybrid free-space optical (FSO) / radio-frequency (RF) systems have emerged as a promising solution for high data- rate wireless communication systems. We consider truncated channel inversion based power adaptation strategy for coherent and non- coherent hybrid FSO/RF systems, employing an adaptive combining scheme. Specifically, we activate the RF link along with the FSO link when FSO link quality is unacceptable, and adaptively set RF transmission power to ensure constant combined signal-to-noise ratio at receiver terminal. Analytical expressions for the outage probability of the hybrid system with and without power adaptation are derived. Numerical examples show that, the hybrid FSO/RF systems with power adaptation achieve considerable outage performance improvement over conventional hybrid FSO/RF systems without power adaptation. © 2015 IEEE.

  7. A Tight Lower Bound to the Outage Probability of Discrete-Input Block-Fading Channels

    CERN Document Server

    Nguyen, Khoa D; Rasmussen, Lars K

    2007-01-01

    In this correspondence, we propose a tight lower bound to the outage probability of discrete-input Nakagami-m block-fading channels. The approach permits an efficient method for numerical evaluation of the bound, providing an additional tool for system design. The optimal rate-diversity trade-off for the Nakagami-m block-fading channel is also derived and a tight upper bound is obtained for the optimal coding gain constant.

  8. Final report of MoReMO 2011-2012. Modelling resilience for maintenance and outage

    Energy Technology Data Exchange (ETDEWEB)

    Gotcheva, N.; Macchi, L.; Oedewald, P. [Technical Research Centre of Finland (VTT), Espoo (Finland); Eitrheim, M.H.R. [Institute for Energy Technology (IFE) (Norway); Axelsson, C.; Reiman, T.; Pietikaeinen, E. [Ringhals AB (NPP), Vattenfall AB (Sweden)

    2013-04-15

    The project Modelling Resilience for Maintenance and Outage (MoReMO) represents a two-year joint effort by VTT Technical Research Centre of Finland, Institute for Energy Technology (IFE, Norway) and Vattenfall (Sweden) to develop and test new approaches for safety management. The overall goal of the project was to present concepts on how resilience can be operationalized and built in a safety critical and socio-technical context. Furthermore, the project also aimed at providing guidance for other organizations that strive to develop and improve their safety performance in a business driven industry. We have applied four approaches in different case studies: Organisational Core Task modelling (OCT), Functional Resonance Analysis Method (FRAM), Efficiency Thoroughness Trade-Off (ETTO) analysis, and Work Practice and Culture Characterisation. During 2011 and 2012 the MoReMO project team has collected data through field observations, interviews, workshops, and document analysis on the work practices and adjustments in maintenance and outage in Nordic NPPs. The project consisted of two sub-studies, one focused on identifying and assessing adjustments and supporting resilient work practices in maintenance activities, while the other focused on handling performance trade-offs in maintenance and outage, as follows: A. Adjustments in maintenance work in Nordic nuclear power plants (VTT and Vattenfall). B. Handling performance trade-offs - the support of adaptive capacities (IFE and Vattenfall). The historical perspective of maintenance and outage management (Chapter 1.1) was provided by Vattenfall. Together, the two sub-studies have provided valuable insights for understanding the rationale behind work practices and adjustments, their effects on resilience, promoting flexibility and balancing between flexibility and reliability. (Author)

  9. Power Outages, Extreme Events and Health: a Systematic Review of the Literature from 2011-2012

    OpenAIRE

    Klinger, Chaamala; Landeg, Owen; Murray, Virginia

    2014-01-01

    Background Extreme events (e.g. flooding) threaten critical infrastructure including power supplies. Many interlinked systems in the modern world depend on a reliable power supply to function effectively. The health sector is no exception, but the impact of power outages on health is poorly understood. Greater understanding is essential so that adverse health impacts can be prevented and/or mitigated. Methods We searched Medline, CINAHL and Scopus for papers about the health impacts of power ...

  10. A Comprehensive Outage Management Model Based on Multi-Objective Decision Analysis%多目标决策分析的电网综合停电管理模型

    Institute of Scientific and Technical Information of China (English)

    郇嘉嘉; 王钢; 李海锋; 汪隆君

    2013-01-01

    针对目前电网综合停电管理中存在的工作量大和效率低下等问题,综合考虑计划停电、临时停电、故障停电、抢修停电、停电施工等各因素造成停电的电网设备,提出电网综合停电管理多目标多约束决策分析模型。该模型以全部待停电设备具体停电时段的排列组合为决策变量,以电网运行方式、供电可靠性要求、运行维护资源配置和停电时间协调情况为约束条件,以电网经济性、可靠性、工作量均衡性联合最优为目标。计算过程采用基于精英保留策略和目标函数值排序的多目标差分进化算法,高效求取全局 Pareto 前沿最优解集,生成多种可选方案,提供给电力企业进行对比分析和最终决策。以RBTS-BUS6为例进行分析计算,验证了所提模型的合理性和有效性。%In allusion to the heavy workload and inefficiency in comprehensive outage management of power grids, synthetically considering shutdown of power equipments caused by outage due to maintenance schedule, temporary outage, outage caused by faults, outage due to rush-repair, outage under construction and so on a multi-objective and multi-restriction decision analysis model for comprehensive outage management of power grid is proposed. In the proposed model, the permutations and combinations of concrete outage time intervals of all power equipments to be interrupted are taken as decision variables;the operation modes of power grid, the requirement on power supply reliability, the resource allocation for operation and maintenance and the coordination of outage time are taken as constraints; the joint optimization of economy, reliability and workload balance of power grid is taken as the objective. In the computation the multi-objective differential evolution algorithm based on elitism strategy and sorting of objective function values is utilized to achieve global Pareto frontier optimum solution set efficiently

  11. Outages of electric power supply resulting from cable failures Boston Edison Company system

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-07-01

    Factual data are provided regarding 5 electric power supply interruptions that occurred in the Boston Metropolitan area during April to June, 1979. Common to all of these outages was the failure of an underground cable as the initiating event, followed by multiple equipment failures. There was significant variation in the voltage ratings and types of cables which failed. The investigation was unable to delineate a single specific Boston Edison design operating or maintenance practice that could be cited as the cause of the outages. After reviewing the investigative report the following actions were recommended: the development and implementation of a plan to eliminate the direct current cable network; develop a network outage restoration plan; regroup primary feeder cables wherever possible to minimize the number of circuits in manholes, and to separate feeders to high load density areas; develop a program to detect incipient cable faults; evaluate the separation of the north and south sections of Back Bay network into separate networks; and, as a minimum, install the necessary facilities to make it possible to re-energize one section without interfering with the other; and re-evaluate the cathodic protection scheme where necessary. (LCL)

  12. Improving the predictive accuracy of hurricane power outage forecasts using generalized additive models.

    Science.gov (United States)

    Han, Seung-Ryong; Guikema, Seth D; Quiring, Steven M

    2009-10-01

    Electric power is a critical infrastructure service after hurricanes, and rapid restoration of electric power is important in order to minimize losses in the impacted areas. However, rapid restoration of electric power after a hurricane depends on obtaining the necessary resources, primarily repair crews and materials, before the hurricane makes landfall and then appropriately deploying these resources as soon as possible after the hurricane. This, in turn, depends on having sound estimates of both the overall severity of the storm and the relative risk of power outages in different areas. Past studies have developed statistical, regression-based approaches for estimating the number of power outages in advance of an approaching hurricane. However, these approaches have either not been applicable for future events or have had lower predictive accuracy than desired. This article shows that a different type of regression model, a generalized additive model (GAM), can outperform the types of models used previously. This is done by developing and validating a GAM based on power outage data during past hurricanes in the Gulf Coast region and comparing the results from this model to the previously used generalized linear models.

  13. Outage behavior of slow fading channels with power control using noisy quantized CSIT

    CERN Document Server

    Ekbatani, Siavash; Jafarkhani, Hamid

    2008-01-01

    The topic of this study is the outage behavior of multiple-antenna slow fading channels with quantized feedback and partial power control. A fixed-rate communication system is considered. It is known from the literature that with error-free feedback, the outage-optimal quantizer for power control has a circular structure. Moreover, the diversity gain of the system increases polynomially with the cardinality of the power control codebook. Here, a similar system is studied, but when the feedback link is error-prone. We prove that in the high-SNR regime, the optimal quantizer structure with noisy feedback is still circular and the optimal Voronoi regions are contiguous non-zero probability intervals. Furthermore, the optimal power control codebook resembles a channel optimized scalar quantizer (COSQ), i.e., the Voronoi regions merge with erroneous feedback information. Using a COSQ, the outage performance of the system is superior to that of a no-feedback scheme. However, asymptotic analysis shows that the diver...

  14. Ergodic and Outage Performance of Fading Broadcast Channels with 1-Bit Feedback

    CERN Document Server

    Niu, Bo; Somekh, Oren; Haimovich, Alexander M

    2010-01-01

    In this paper, the ergodic sum-rate and outage probability of a downlink single-antenna channel with K users are analyzed in the presence of Rayleigh flat fading, where limited channel state information (CSI) feedback is assumed. Specifically, only 1-bit feedback per fading block per user is available at the base station. We first study the ergodic sum-rate of the 1-bit feedback scheme, and consider the impact of feedback delay on the system. A closed-form expression for the achievable ergodic sum-rate is presented as a function of the fading temporal correlation coefficient. It is proved that the sum-rate scales as loglogK, which is the same scaling law achieved by the optimal non-delayed full CSI feedback scheme. The sum-rate degradation due to outdated CSI is also evaluated in the asymptotic regimes of either large K or low SNR. The outage performance of the 1-bit feedback scheme for both instantaneous and outdated feedback is then investigated. Expressions for the outage probabilities are derived, along w...

  15. Partner cooperation with decode-and-forward: Closed-form outage analysis and comparison

    KAUST Repository

    Benjillali, Mustapha

    2013-01-01

    In this paper, we investigate the outage performance of "partner cooperation" based on opportunistic Decodeand- Forward with constrained partial selection and reactive relaying strategies in dual-hop cooperative Nakagami-m fading links. The source/destination, which is based on the unique knowledge of local channel state information, selects the best relay to increase the chances of cooperation in both uplink and downlink communications when the direct link is also available. After deriving new expressions for the cumulative distribution functions of the variables of interest, the outage probability of the system is obtained in closed-form. We also derive the ε-outage capacity in different particular cases, and the obtained results - when the channel model is reduced to a Rayleigh fading - either are new or correspond to those previously obtained in other works. Simulation results confirm the accuracy of our analysis for a large selection of system and fading parameters and provide a new insight into the design and optimization of cooperative configurations. © 2012 IEEE.

  16. Outage Analysis of Mixed Underlay Cognitive RF MIMO and FSO Relaying with Interference Reduction

    KAUST Repository

    Al-Qahtani, Fawaz S.

    2017-03-22

    In this paper, we study the outage performance of multiuser mixed underlay radio frequency (RF)/multidestinations free-space optical (FSO) links. For RF links, we consider a secondary network with multiple users that can communicate with multiple destinations through a relaying node. The relay is equipped with an antenna array at the RF side, and it uses the amplify-and-forward (AF) protocol. The primary users (PUs) are equipped with multiple antennas at transmit and receive nodes. The RF link is subjected to the aggregate PUs interference effect on the secondary network. To reduce the effect of PUs interference on secondary network at the relay node, two interference cancellation (IC) schemes are adopted, which vary in terms of complexity and achieved performance. On the other hand, the multidestination FSO links can be exploited to further enhance the quality of the second hop, and their associated channel models account for pointing errors, intensity modulation/direct detection, and heterodyne detection. For the aforementioned system model, we obtain exact and asymptotic closed-form expressions for the end-to-end outage probability. To further enhance system performance, optimal power allocation between the two hops is obtained based on the derived asymptotic outage probability expressions.

  17. An exact power series formula of the outage probability with noise and interference over generalized fading channels

    KAUST Repository

    Rached, Nadhir Ben

    2016-12-24

    In this paper, we develop a generalized momentbased approach for the evaluation of the outage probability (OP) in the presence of co-channel interference and additive white Gaussian noise. The proposed method allows the evaluation of the OP of the signal-to-interference-plus-noise ratio by a power series expansion in the threshold value. Its main advantage is that it does not require a particular distribution for the interference channels. The only necessary ingredients are a power series expansion for the cumulative distribution function of the desired user power and the cross-moments of the interferers\\' powers. These requirements are easily met in many practical fading models, for which the OP might not be obtained in closed-form expression. For a sake of illustration, we consider the application of our method to the Rician fading environment. Under this setting, we carry out a convergence study of the proposed power series and corroborate the validity of our method for different values of fading parameters and various numbers of co-channel interferers.

  18. Multi-Timescale Cascading Outage Model Considering Generator Excitation Protection and OLTC%考虑发电机励磁保护和OLTC的多时间尺度连锁故障模型

    Institute of Scientific and Technical Information of China (English)

    姚锐; 黄少伟; 刘锋

    2015-01-01

    Voltage and reactive power characteristics play an important role in cascading outages and blackouts in power systems. In this paper, a multi-timescale cascading outage model considering on-load tap changer (OLTC) and generator excitation protection was proposed. This model proposed a multi-timescale cascading outage simulation framework, in which clear expression of time in cascading outage simulation was realized, thus overcame limitation of traditional models. Modeling of generator excitation protection and OLTC simulation were introduced in this model. The IEEE-30 system case studies analyzed mechanisms of generator excitation protection and OLTC, and their influence on cascading outage risk and process. Moreover, phrasal characteristics of cascading outages are analyzed using this model.%世界范围内多次连锁故障和大停电事故表明,无功电压相关因素对连锁故障具有重要影响。提出了一种计及有载调压变压器(on-load tap changer,OLTC)和发电机励磁保护的多时间尺度大停电模型。该模型提出了对无功电压具有重要影响的发电机励磁保护和OLTC动作的建模方法,并进一步基于该模型提出了多时间尺度连锁故障模拟方法,实现了连锁故障动态过程的清晰描述,克服了传统连锁故障模型在此方面的局限性。文中用IEEE 30节点系统进行了连锁故障仿真计算,分析了发电机励磁保护、OLTC动作等与无功电压密切相关的因素对连锁故障的影响及机理,并揭示了连锁故障的若干阶段性特征。

  19. Analysis of Chain of Events in Major Historic Power Outages

    Directory of Open Access Journals (Sweden)

    HUANG, T.

    2014-08-01

    Full Text Available Contemporary power systems are facing increasing intricate conditions that have never been considered when initially designing the infrastructure, such as malicious threats, accommodating smart grids, etc. As a consequence, blackouts albeit seldom but stubbornly keep appearing from time to time the world around, and demonstrate their devastating capability to create vast damage on both power systems and the society at large. Patterns of the blackout starting from the first triggering events to the system final status have emerged. A framework of a coding system was proposed in this paper in order to capture the common feature in the system evolution during the development of cascades. Cascades in a blackout can be tracked by a chain of events with the help of the codes. It is facile to adopt the framework to build up a knowledge base of blackouts. By applying the proposed framework to 31 selected historic blackouts, most frequent events, effects and origins are identified; the findings can provide useful information for grid designers and security experts for ranking the most imminent issues in their study.

  20. Outage probability analysis of a secondary user in an underlay dual hop cognitive amplify and forward relay network

    Directory of Open Access Journals (Sweden)

    Kiran Chandra

    2016-09-01

    Full Text Available This paper presents the performance evaluation of a secondary user (SU in an underlay cognitive dual-hop relaying system considering instantaneous as well as average channel information of the interfering links (from the secondary source and relay to the primary receiver and the data link from the secondary source to relay, to calculate transmit power and amplifying gain of secondary system. Comparison of above mentioned cases is done for two different scenarios – with direct path and without direct path. We evaluate the performance considering two different diversity techniques namely as selection combining (SC and maximum ratio combining (MRC. The effect of different fading channels (Rayleigh and Nakagami on the outage performance of the SU for the two diversity techniques is also shown. The outage probability of the SU is reduced when the diversity techniques are used (with direct path as compared to the outage probability of SU without direct path. We find that the outage performance is better for instantaneous channel information as compared to average channel information for the links. We observe that MRC provides better performance than SC. Furthermore, this work shows that the outage performance of the SU has been improved when the Nakagami fading channel (m = 2 is considered instead of Rayleigh fading channel.

  1. Economic costs of electrical system instability and power outages caused by snakes on the Island of Guam

    Science.gov (United States)

    Fritts, T.H.

    2002-01-01

    The Brown Tree Snake, Boiga irregularis, is an introduced species on Guam where it causes frequent electrical power outages. The snake's high abundance, its propensity for climbing, and use of disturbed habitats all contribute to interruption of Guam's electrical service and the activities that depend on electrical power. Snakes have caused more than 1600 power outages in the 20-yr period of 1978-1997 and most recently nearly 200 outages per year. Single outages spanning the entire island and lasting 8 or more hours are estimated to cost in excess of $3,000,000 in lost productivity, but the costs of outages that involve only parts of the island or those of shorter durations are more difficult to quantify. Costs to the island's economy have exceeded $4.5 M per year over a 7-yr period without considering repair costs, damage to electrical equipment, and lost revenues. Snakes pose the greatest problem on high voltage transmission lines, on transformers, and inside electrical substations.

  2. Outage Probability of SINR for Underlay Cognitive Radio Systems in Nakagami Fading

    Science.gov (United States)

    Jarrouj, Jiana; Blagojevic, Vesna; Ivanis, Predrag

    2014-11-01

    In this paper underlay cognitive radio system is analyzed in Nakagami fading environment, for the case when the available channel state information (CSI) of the link from the secondary transmitter to the primary receiver is outdated. We considered the case when both interference and transmit power constraints are applied. The impact of the co-channel interference that originates from the primary user is analyzed in details. The exact closed-form expressions for probability density function, outage probability, and the moments of signal-to-interference and noise ratio (SINR) at the secondary user's receiver are derived. The analytical expressions are verified by using independent Monte Carlo simulation method.

  3. Efficient Outage Probability Evaluation of Diversity Receivers Over Generalized Gamma Channels

    KAUST Repository

    Ben Issaid, Chaouki

    2016-10-01

    In this paper, we are interested in determining the cumulative distribution function of the sum of generalized Gamma in the setting of rare event simulations. To this end, we present an efficient importance sampling estimator. The main result of this work is the bounded relative property of the proposed estimator. This result is used to accurately estimate the outage probability of multibranch maximum ratio combining and equal gain combining diversity receivers over generalized Gamma fading channels. Selected numerical simulations are discussed to show the robustness of our estimator compared to naive Monte Carlo.

  4. Outage Analysis of Opportunistic Cooperative Ad Hoc Networks with Randomly Located Nodes

    Institute of Scientific and Technical Information of China (English)

    Cheng-Wen Xing; Hai-Chuan Ding; Guang-Hua Yang; Shao-Dan Ma; Ze-Song Fei

    2013-01-01

    In this paper,an opportunistic cooperative ad hoc sensor network with randomly located nodes is analyzed.The randomness of nodes' locations is captured by a homogeneous Poisson point process.The effect of imperfect interference cancellation is also taken into account in the analysis.Based on the theory of stochastic geometry,outage probability and cooperative gain are derived.It is demonstrated that explicit performance gain can be achieved through cooperation.The analyses are corroborated by extensive simulation results and the analytical results can thus serve as a guideline for wireless sensor network design.

  5. Outage performance of two-way DF relaying systems with a new relay selection metric

    KAUST Repository

    Hyadi, Amal

    2012-04-01

    This paper investigates a new constrained relay selection scheme for two-way relaying systems where two end terminals communicate simultaneously via a relay. The introduced technique is based on the maximization of the weighted sum rate of both users. To evaluate the performance of the proposed system, the outage probability is derived in a general case (where an arbitrary channel is considered), and then over independently but not necessarily identically distributed (i.n.i.d.) Rayleigh fading channels. The analytical results are verified through simulations. © 2012 IEEE.

  6. Exact outage analysis of incremental decode-and-forward opportunistic relaying

    KAUST Repository

    Tourki, Kamel

    2010-11-01

    In this paper, we investigate a dual-hop decode-andforward opportunistic relaying scheme where the selected relay chooses to cooperate only if the source-destination channel is of an unacceptable quality. In our study, we derive exact closed-form expression for the outage probability based on the exact statistics of each hop. Furthermore, we perform asymptotic analysis and we deduce the diversity order of the scheme. We validate our analysis by showing that performance simulation results coincide with our analytical results over different network architectures. © 2010 IEEE.

  7. Outage Probability in {\\eta}-{\\mu}/{\\eta}-{\\mu} Interference-limited Scenarios

    CERN Document Server

    Paris, Jose F

    2011-01-01

    In this Correspondence exact closed-form expressions are derived for the outage probability (OP) in scenarios where both the signal of interest (SOI) and the interfering signals experience {\\eta}-{\\mu} fading and the background noise can be neglected. With the only assumption that the {\\mu} parameter is a positive integer number for the interfering signals, the derived expressions are given in elementary terms for maximal ratio combining (MRC) with independent branches. The analysis is also valid when the {\\mu} parameters of the pre-combining SOI power envelopes are positive integer or half-integer numbers and the SOI is formed at the receiver from spatially correlated MRC.

  8. MATCASC: A tool to analyse cascading line outages in power grids

    CERN Document Server

    Koç, Yakup; Araujo, Nuno A M; Warnier, Martijn

    2013-01-01

    Blackouts in power grids typically result from cascading failures. The key importance of the electric power grid to society encourages further research into sustaining power system reliability and developing new methods to manage the risks of cascading blackouts. Adequate software tools are required to better analyze, understand, and assess the consequences of the cascading failures. This paper presents MATCASC, an open source MATLAB based tool to analyse cascading failures in power grids. Cascading effects due to line overload outages are considered. The applicability of the MATCASC tool is demonstrated by assessing the robustness of IEEE test systems and real-world power grids with respect to cascading failures.

  9. Outage and ser performance of an opportunistic multi-user underlay cognitive network

    KAUST Repository

    Khan, Fahd Ahmed

    2012-10-01

    Consider a multi-user underlay cognitive network where multiple cognitive users concurrently share the spectrum with a primary network and a single secondary user is selected for transmission. The channel is assumed to have independent but not identical Nakagami-m fading. Closed form expressions for the outage performance and the symbol-error-rate performance of the opportunistic multi-user secondary network are derived when a peak interference power constraint is imposed on the secondary network in addition to the limited peak transmit power of each secondary user. © 2012 IEEE.

  10. Outage Performance Based on Optimal Power Allocation in Cognitive Multi-node Relay Networks%认知多中继网络中基于最佳功率分配的中断性能

    Institute of Scientific and Technical Information of China (English)

    宋耀莲; 酆广增

    2013-01-01

    In this paper,we investigate the power allocation schemes of cognitive multi-node relay networks. A simple optimal power allocation (OPA) method is proposed, and the optimal solution is given. We simulate the outage performance of different location of cognitive relay and investigate spectrum sensing and cognitive multi-node relay cooperative transmission. The numerical results show that the outage performance of optimal power allocation is superior to that of equal power allocation ( EPA). Furthermore, there exists an optimal spectrum sensing time to optimize the outage performance of cognitive multi-node relay networks.%研究了认知多中继网络的功率分配方案,提出了简单的最优功率分配(OPA)方法,并给出最优解.仿真了不同的认知中继位置对认知系统中断性能的影响,并联合考虑频谱感知和认知多中继协作传输两个过程.仿真结果表明,文中提出的最佳功率分配方案的中断性能优于等功率分配(EPA)方案,且存在最佳的感知时间使认知多中继网络的中断性能最优.

  11. Outage Performance of Cooperative Relay Selection with Multiple Source and Destination Antennas over Dissimilar Nakagami-m Fading Channels

    Science.gov (United States)

    Lee, Wooju; Yoon, Dongweon

    Cooperative relay selection, in which one of multiple relays is selected to retransmit the source signal to the destination, has received considerable attention in recent years, because it is a simple way to obtain cooperative diversity in wireless networks. The exact expression of outage probability for a decode-and-forward cooperative relay selection with multiple source and destination antennas over Rayleigh fading channels was recently derived in [9]. In this letter, we derive the exact expressions of outage probability and diversity-multiplexing tradeoff over independent and non-identically distributed Nakagami-m fading channels as an extension of [9]. We then analyze the effects of various parameters such as fading conditions, number of relays, and number of source and destination antennas on the outage probability.

  12. Outage performance of opportunistic two-way amplify-and-forward relaying with outdated channel state information

    KAUST Repository

    Hwang, Kyusung

    2013-09-01

    In this paper, we study the outage performance of an amplify-and-forward (AF)-based two-way relaying (TWR) system with multiple relays where a single relay selection is performed based on outdated channel state information (CSI). Specifically, we propose a single relay selection scheme in AF-based TWR system under outdated CSI conditions. With this policy, we offer a statistical analysis of the signal-to-noise ratio per hop and analyze the outage probability with asymmetric outage thresholds based on CSI-assisted AF protocol. Additionally, we provide the exact and asymptotic expressions based on the provided statistical/joint statistical analyses of a dual-hop AF transmission. Finally, we verify our analytical results with some selected computer-based simulation results. © 1972-2012 IEEE.

  13. Outage probability of dual-hop partial relay selection with feedback delay in the presence of interference

    KAUST Repository

    Al-Qahtani, Fawaz S.

    2011-09-01

    In this paper, we investigate the outage performance of a dual-hop relaying systems with partial relay selection and feedback delay. The analysis considers the case of Rayleigh fading channels when the relaying station as well as the destination undergo mutually independent interfering signals. Particularly, we derive the cumulative distribution function (c.d.f.) of a new type of random variable involving sum of multiple independent exponential random variables, based on which, we present closed-form expressions for the exact outage probability of a fixed amplify-and-forward (AF) and decode-and-forward (DF) relaying protocols. Numerical results are provided to illustrate the joint effect of the delayed feedback and co-channel interference on the outage probability. © 2011 IEEE.

  14. On Outage Probability and Diversity-Multiplexing Tradeoff in MIMO Relay Channels

    CERN Document Server

    Loyka, Sergey

    2011-01-01

    Fading MIMO relay channels are studied analytically, when the source and destination are equipped with multiple antennas and the relays have a single one. Compact closed-form expressions are obtained for the outage probability under i.i.d. and correlated Rayleigh-fading links. Low-outage approximations are derived, which reveal a number of insights, including the impact of correlation, of the number of antennas, of relay noise and of relaying protocol. The effect of correlation is shown to be negligible, unless the channel becomes almost fully correlated. The SNR loss of relay fading channels compared to the AWGN channel is quantified. The SNR-asymptotic diversity-multiplexing tradeoff (DMT) is obtained for a broad class of fading distributions, including, as special cases, Rayleigh, Rice, Nakagami, Weibull, which may be non-identical, spatially correlated and/or non-zero mean. The DMT is shown to depend not on a particular fading distribution, but rather on its polynomial behavior near zero, and is the same ...

  15. Analysis of heterogeneous boron dilution transients during outages with APROS 3D nodal core model

    Energy Technology Data Exchange (ETDEWEB)

    Kuopanportti, Jaakko [Fortum Power and Heat Ltd, Nuclear Production, Fortum (Finland)

    2015-09-15

    A diluted water plug can form inside the primary coolant circuit if the coolant flow has stopped at least temporarily. The source of the clean water can be external or the fresh water can build up internally during boiling/condensing heat transfer mode, which can occur if the primary coolant inventory has decreased enough during an accident. If the flow restarts in the stagnant primary loop, the diluted water plug can enter the reactor core. During outages after the fresh fuel has been loaded and the temperature of the coolant is low, the dilution potential is the highest because the critical boron concentration is at the maximum. This paper examines the behaviour of the core as clean or diluted water plugs of different sizes enter the core during outages. The analysis were performed with the APROS 3D nodal core model of Loviisa VVER-440, which contains an own flow channel and 10 axial nodes for each fuel assembly. The widerange cross section data was calculated with CASMO-4E. According to the results, the core can withstand even large pure water plugs without fuel failures on natural circulation. The analyses emphasize the importance of the simulation of the backflows inside the core when the reactor is on natural circulation.

  16. Exploiting Outage and Error Probability of Cooperative Incremental Relaying in Underwater Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Hina Nasir

    2016-07-01

    Full Text Available This paper embeds a bi-fold contribution for Underwater Wireless Sensor Networks (UWSNs; performance analysis of incremental relaying in terms of outage and error probability, and based on the analysis proposition of two new cooperative routing protocols. Subject to the first contribution, a three step procedure is carried out; a system model is presented, the number of available relays are determined, and based on cooperative incremental retransmission methodology, closed-form expressions for outage and error probability are derived. Subject to the second contribution, Adaptive Cooperation in Energy (ACE efficient depth based routing and Enhanced-ACE (E-ACE are presented. In the proposed model, feedback mechanism indicates success or failure of data transmission. If direct transmission is successful, there is no need for relaying by cooperative relay nodes. In case of failure, all the available relays retransmit the data one by one till the desired signal quality is achieved at destination. Simulation results show that the ACE and E-ACE significantly improves network performance, i.e., throughput, when compared with other incremental relaying protocols like Cooperative Automatic Repeat reQuest (CARQ. E-ACE and ACE achieve 69% and 63% more throughput respectively as compared to CARQ in hard underwater environment.

  17. Outage performance analysis of underlay cognitive RF and FSO wireless channels

    KAUST Repository

    Ansari, Imran Shafique

    2014-09-01

    In this work, the outage performance analysis of a dual-hop transmission system composed of asymmetric radio frequency (RF) channel cascaded with a free-space optical (FSO) link is presented. For the RF link, an underlay cognitive network is considered where the secondary users share the spectrum with licensed primary users. Indoor femtocells act as a practical example for such networks. More specifically, it is assumed that the RF link applies power control to maintain the interference at the primary network below a predetermined threshold. While the RF channel is modeled by the Rayleigh fading distribution, the FSO link is modeled by a unified Gamma-Gamma turbulence distribution. The FSO link accounts for pointing errors and both types of detection techniques (i.e. heterodyne detection as well as intensity modulation/direct detection (IM/DD)). With this model, a new exact closed-form expression is derived for the outage probability of the end-To-end signal-To-noise ratio of these systems in terms of the Meijer\\'s G function and the Fox\\'s H functions under fixed amplify-and-forward relay scheme. All new analytical results are verified via computer-based Monte-Carlo simulations and are illustrated by some selected numerical results.

  18. Fundamental Limits of Parallel Optical Wireless Channels: Capacity Results and Outage Formulation

    KAUST Repository

    Chaaban, Anas

    2016-10-26

    Multi-channel (MC) optical wireless communication (OWC) systems employing wave-division multiplexing for outdoors free-space optical communications, or multi-user timedivision multiple access for indoors visible-light communications, e.g., can be modeled as parallel channels. Multi-input multioutput OWC systems can also be transformed, possibly with some performance loss, to parallel channels using pre-/postcoding. Studying the performance of such MC-OWC systems requires characterizing the capacity of the underlying parallel channels. In this paper, upper and lower bounds on the capacity of constant parallel OWC channels with a total average intensity constraint are derived. Then, the paper focuses on finding intensity allocations that maximize the lower bounds given channel-state information at the transmitter (CSIT). Due to its nonconvexity, the KKT conditions are used to describe a list of candidate allocations. Instead searching exhaustively for the best solution, low-complexity near-optimal algorithms are proposed. The resulting optimized lower bound nearly coincides with capacity at high signal-to-noise ratio (SNR). Under a quasi-static channel model and in the absence of CSIT, outage probability upper and lower bounds are derived. Those bounds also meet at high SNR, thus characterizing the outage capacity in this regime. Finally, the results are extended to a system with both average and peak intensity constraints.

  19. Outage Analysis of Practical FSO/RF Hybrid System With Adaptive Combining

    KAUST Repository

    Rakia, Tamer

    2015-08-01

    Hybrid free-space optical (FSO)/radio-frequency (RF) systems have emerged as a promising solution for high-data-rate wireless transmission. We present and analyze a transmission scheme for the hybrid FSO/RF communication system based on adaptive combining. Specifically, only FSO link is active as long as the instantaneous signal-to-noise ratio (SNR) at the FSO receiver is above a certain threshold level. When it falls below this threshold level, the RF link is activated along with the FSO link and the signals from the two links are combined at the receiver using a dual-branch maximal ratio combiner. Novel analytical expression for the cumulative distribution function (CDF) of the received SNR for the proposed hybrid system is obtained. This CDF expression is used to study the system outage performance. Numerical examples are presented to compare the outage performance of the proposed hybrid FSO/RF system with that of the FSO-only and RF-only systems. © 1997-2012 IEEE.

  20. An Efficient Simulation Scheme of the Outage Probability with Co-Channel Interference

    KAUST Repository

    Rached, Nadhir B.

    2016-03-28

    © 2015 IEEE. The outage probability (OP) of the signal-to-interference-plus-noise ratio (SINR) is an important metric used to evaluate the performance of wireless communication systems operating over fading channels. One major difficulty toward assessing the OP is that, in most of the realistic scenarios, closed-form expressions cannot be derived. This is for instance the case of Log-normal fading environments, in which evaluating the OP of the SINR amounts to computing the probability that a sum of correlated Log-normal variates exceeds a given threshold. Since such a probability is not known to admit a closed-form expression, it has thus far been evaluated by several approximation techniques, the accuracies of which are unfortunately not guaranteed in the interesting region of small outage probabilities. For these regions, simulation techniques based on variance reduction algorithms can represent a good alternative, being well-recognized to be quick and highly accurate for estimating rare event probabilities. This constitutes the major motivation behind our work. More specifically, we propose an efficient importance sampling approach which is based on a covariance matrix scaling technique and illustrate its computational gain over naive Monte Carlo simulations through some selected simulation results.

  1. On the Stringing Construction Technology of Transmission Lines Crossing without Power Outage%浅析输电线路不停电跨越架线施工技术

    Institute of Scientific and Technical Information of China (English)

    高玉恒

    2014-01-01

    With the development of economy, electric power industry develops faster and faster and transmission lines increase accordingly. At present, the transmission line is faced with the status that new line crosses with the live line. If power outage is needed to apply for a region, the power construction is very complicated, even if the power outage demand is met, it also needs a long time to carry on the construction, thus affecting the whole power grid construction. In order to solve this problem, the crossing construction technology without power outage arises at the historic moment. Therefore, researchers must analyze and summarize the stringing construction technology of transmission lines crossing without power outage. Combined with work experience for many years, the author makes a brief analysis on the stringing construction technology of transmission lines crossing without power outage from the general method and process of the technology.%随着经济的发展,电力行业发展越来越快,输电线路因此不断增加。目前,我国输电线路面临着新建线路与带电线路交叉跨越的现状,如果某地区需要申请停电,停电施工会非常复杂,即使满足了停电需求,施工也要等待很长一段时间,从而影响整个电网工程建设。为了解决这一难题,不停电跨越施工技术应运而生,因此,研究人员必须对输电线路不停电跨越架线施工技术进行分析和总结。笔者结合多年工作经验,从不停电跨越架线施工的一般方法和流程着手,对输电线路不停电跨越架线施工技术作了简要分析。

  2. Emergency preparedness for power outages and wi-fi loss: tips for students and educators of online courses.

    Science.gov (United States)

    Heithaus, Teresa

    2015-01-01

    Severe weather can impact online education due to a loss of power and Internet access that can last hours or weeks. Planning for such losses is essential to enable participation in the online classroom. This article discusses measures that can be used to maintain an online presence in the event of a power outage or loss of Wi-Fi.

  3. Are Older Adults Prepared to Ensure Food Safety during Extended Power Outages and Other Emergencies?: Findings from a National Survey

    Science.gov (United States)

    Kosa, Katherine M.; Cates, Sheryl C.; Karns, Shawn; Godwin, Sandria L.; Coppings, Richard J.

    2012-01-01

    Natural disasters and other emergencies can cause an increased risk of foodborne illness. We conducted a nationally representative survey to understand consumers' knowledge and use of recommended practices during/after extended power outages and other emergencies. Because older adults are at an increased risk for foodborne illness, this paper…

  4. Living at the Edge: A Large Deviations Approach to the Outage MIMO Capacity

    CERN Document Server

    Kazakopoulos, P; Moustakas, A L; Caire, G

    2009-01-01

    Using a large deviations approach we calculate the probability distribution of the mutual information of MIMO channels in the limit of large antenna numbers. In contrast to previous methods that only focused at the distribution close to its mean (thus obtaining an asymptotically Gaussian distribution), we calculate the full distribution, including its tails which strongly deviate from the Gaussian behavior near the mean. The resulting distribution interpolates seamlessly between the Gaussian approximation for rates $R$ close to the ergodic value of the mutual information and the approach of Zheng and Tse for large signal to noise ratios $\\rho$. This calculation provides us with a tool to obtain outage probabilities analytically at any point in the $(R, \\rho, N)$ parameter space, as long as the number of antennas $N$ is not too small. In addition, this method also yields the probability distribution of eigenvalues constrained in the subspace where the mutual information per antenna is fixed to $R$ for a given ...

  5. A A field test for extremity dose assessment during outages at Korean nuclear power plants.

    Science.gov (United States)

    Kim, Hee Geun; Kong, Tae Young

    2013-05-01

    During maintenance on the water chamber of a steam generator, the pressuriser heater and the pressure tube feeder in nuclear power plants, workers are likely to receive high radiation doses due to the severe workplace conditions. In particular, it is expected that workers' hands would receive the highest radiation doses because of their contact with the radioactive materials. In this study, field tests for extremity dose assessments in radiation workers undertaking contact tasks with high radiation doses were conducted during outages at pressurised water reactors and pressurised heavy water reactors in Korea. In the test, the radiation workers were required to wear additional thermoluminescent dosemeters (TLDs) on their backs and wrists and an extremity dosemeter on the finger, as well as a main TLD on the chest while performing the maintenance tasks.

  6. Outage Probability of the Gaussian MIMO Free-Space Optical Channel with PPM

    CERN Document Server

    Letzepis, Nick

    2008-01-01

    The free-space optical channel has the potential to facilitate inexpensive, wireless communication with fiber-like bandwidth under short deployment timelines. However, atmospheric effects can significantly degrade the reliability of a free-space optical link. In particular, atmospheric turbulence causes random fluctuations in the irradiance of the received laser beam, commonly referred to as scintillation. The scintillation process is slow compared to the large data rates typical of optical transmission. As such, we adopt a quasi-static block fading model and study the outage probability of the channel under the assumption of orthogonal pulse-position modulation. We investigate the mitigation of scintillation through the use of multiple lasers and multiple apertures, thereby creating a multiple-input multiple output (MIMO) channel. Non-ideal photodetection is also assumed such that the combined shot noise and thermal noise are considered as signal-independent Additive Gaussian white noise. Assuming perfect re...

  7. Outage probability of dual-hop FSO fixed gain relay transmission systems

    KAUST Repository

    Zedini, Emna

    2016-12-24

    In this paper, we analyze the end-to-end performance of dual-hop free-space optical (FSO) fixed gain relaying systems in the presence of atmospheric turbulence as well as pointing errors. More specifically, an exact closed-form expression for the outage probability is presented in terms of the bivariate Fox\\'s H function that accounts for both heterodyne detection as well as intensity modulation with direct detection. At high signal-to-noise ratio (SNR) regime, we provide very tight asymptotic result for this performance metric in terms of simple elementary functions. By using dual-hop FSO relaying, we demonstrate a better system performance as compared to the single FSO link. Numerical and Monte-Carlo simulation results are provided to verify the accuracy of the newly proposed results, and a perfect agreement is observed.

  8. Accurate outage analysis of incremental decode-and-forward opportunistic relaying

    KAUST Repository

    Tourki, Kamel

    2011-04-01

    In this paper, we investigate a dual-hop decode-and-forward opportunistic relaying scheme where the selected relay chooses to cooperate only if the source-destination channel is of an unacceptable quality. We first derive the exact statistics of received signal-to-noise (SNR) over each hop with co-located relays, in terms of probability density function (PDF). Then, the PDFs are used to determine very accurate closed-form expression for the outage probability for a transmission rate R. Furthermore, we perform asymptotic analysis and we deduce the diversity order of the scheme. We validate our analysis by showing that performance simulation results coincide with our analytical results over different network architectures. © 2011 IEEE.

  9. Analysis of 12 electric power system outages/disturbances impacting the Florida Peninsula

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-12-01

    Between January 3 and August 3, 1979, there were 12 occasions on which electric power was curtailed or public appeals were made to customers to reduce their load in Peninsular Florida due to bulk electric power supply problems. The Economic Regulatory Administration (ERA) of the US DOE, pursuant to its electric power supply adequacy and reliability responsibilities, initiated a twofold analysis of the bulk power supply situation in Florida. The first phase of the analysis evaluated the technical and engineering aspects of the overall Florida bulk power supply system with special attention given to the City of Jacksonville's electric system. The second phase evaluated the socioeconomic impacts of the bulk power supply outages on residential customers in Jacksonville. The 12 disturbances are described and a comparative analysis of the causes is presented. (LCL)

  10. Outage Performance Analysis of Cooperative Diversity with MRC and SC in Correlated Lognormal Channels

    Directory of Open Access Journals (Sweden)

    Skraparlis D

    2009-01-01

    Full Text Available Abstract The study of relaying systems has found renewed interest in the context of cooperative diversity for communication channels suffering from fading. This paper provides analytical expressions for the end-to-end SNR and outage probability of cooperative diversity in correlated lognormal channels, typically found in indoor and specific outdoor environments. The system under consideration utilizes decode-and-forward relaying and Selection Combining or Maximum Ratio Combining at the destination node. The provided expressions are used to evaluate the gains of cooperative diversity compared to noncooperation in correlated lognormal channels, taking into account the spectral and energy efficiency of the protocols and the half-duplex or full-duplex capability of the relay. Our analysis demonstrates that correlation and lognormal variances play a significant role on the performance gain of cooperative diversity against noncooperation.

  11. A unified simulation approach for the fast outage capacity evaluation over generalized fading channels

    KAUST Repository

    Rached, Nadhir B.

    2015-06-14

    The outage capacity (OC) is among the most important performance metrics of communication systems over fading channels. The evaluation of the OC, when Equal Gain Combining (EGC) or Maximum Ratio Combining (MRC) diversity techniques are employed, boils down to computing the Cumulative Distribution Function (CDF) of the sum of channel envelopes (equivalently amplitudes) for EGC or channel gain (equivalently squared enveloped/amplitudes) for MRC. Closed-form expressions of the CDF of the sum of many generalized fading variates are generally unknown and constitute open problems. In this paper, we develop a unified hazard rate twisting Importance Sampling (IS) based approach to efficiently estimate the CDF of the sum of independent arbitrary variates. The proposed IS estimator is shown to achieve an asymptotic optimality criterion, which clearly guarantees its efficiency. Some selected simulation results are also shown to illustrate the substantial computational gain achieved by the proposed IS scheme over crude Monte-Carlo simulations.

  12. Global NDE Best Practice for Technology Improvement, Outage Management, Foreign Material Exclusion and Dose Control

    Energy Technology Data Exchange (ETDEWEB)

    Glass, S. W.; Mohr, F.

    2010-07-01

    Non Destructive Examination (NDE) is a critical element of both Boiling Water and Pressurized Water Reactor outages. Frequently this includes critical path activity so both the utility and the inspection vendor are under intense pressure to perform the work quickly. Concurrent with AREVA's new global organization of NDE resources, AREVA NDE SOLUTIONS, efforts have intensified for global application of lessons learned and best practices. These best practices include new developments as well as continuous improvements to well established tools and NDE techniques. Advancements range from steam generator robots, advanced steam generator deposit characterization sensors and method, new phased array approaches for PWR and BWR reactor vessel examination, new sensors and approaches for RPV head examinations, plus advanced internals examination robots and methods. In addition to specialized tools and techniques, best practice includes numerous management innovations. AREVA's multi-disciplined integrated nuclear worker strategy helps to minimize the total number of personnel deployed to multi-task outages. Specific design and on-site practice has been implemented to minimize or eliminate foreign material from the reactor system and vigorous pursuit of dose management practices keeps our nuclear worker dose as low as reasonably achievable. The industry is moving to much more conservative nuclear worker dose limits. While this is proving to be an issue with many vendors, AREVA has had an internal policy of <2R since 2006. Globalizing the organization also helps AREVA manage peaks and unplanned emergency inspections from an enlarged pool of globally qualified inspection personnel and tools. (Author)

  13. Use of a holder-vacuum tube device to save on-site hands in preparing urine samples for head-space gas-chromatography, and its application to determine the time allowance for sample sealing.

    Science.gov (United States)

    Kawai, Toshio; Sumino, Kimiaki; Ohashi, Fumiko; Ikeda, Masayuki

    2011-01-01

    To facilitate urine sample preparation prior to head-space gas-chromatographic (HS-GC) analysis. Urine samples containing one of the five solvents (acetone, methanol, methyl ethyl ketone, methyl isobutyl ketone and toluene) at the levels of biological exposure limits were aspirated into a vacuum tube via holder, a device commercially available for venous blood collection (the vacuum tube method). The urine sample, 5 ml, was quantitatively transferred to a 20-ml head-space vial prior to HS-GC analysis. The loaded tubes were stored at +4 ℃ in dark for up to 3 d. The vacuum tube method facilitated on-site procedures of urine sample preparation for HS-GC with no significant loss of solvents in the sample and no need of skilled hands, whereas on-site sample preparation time was significantly reduced. Furthermore, no loss of solvents was detected during the 3-d storage, irrespective of hydrophilic (acetone) or lipophilic solvent (toluene). In a pilot application, high performance of the vacuum tube method in sealing a sample in an air-tight space succeeded to confirm that no solvent will be lost when sealing is completed within 5 min after urine voiding, and that the allowance time is as long as 30 min in case of toluene in urine. The use of the holder-vacuum tube device not only saves hands for transfer of the sample to air-tight space, but facilitates sample storage prior to HS-GC analysis.

  14. Reasons of Air Separator Outage Accident Caused by Gas Discharging and Countermeasures%煤气放空造成安钢制氧机停车事故的原因和对策分析

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    Outage of many air separators caused by gas discharging is the first time in air separating history of Anyang Iron & Steel Co., Ltd. The accident causes are analyzed. The related improvement suggestions are offered to avoid such accident.%  煤气放空造成制氧机大面积停车是安钢制氧史上第一次。对事故原因进行了分析,提出了整改意见,避免了此事故再次发生。

  15. Research on mobile monitor based on low voltage power outage management%基于移动式用电监测仪的低压停电管理研究

    Institute of Scientific and Technical Information of China (English)

    骆华; 麦霭庭; 单伟权; 单志球

    2015-01-01

    研究在低压客户侧安装负荷监测装置,实时采集客户的停复电信息及电流电压数据;研究在配网生产系统中新增的低压计划停电模块,实时采集低压计划停电事件,并按要求提前短信通知客户;研究通过细化GIS拓扑关系的层级,实现“变—分支线—户”的准确定位,实现低压停电客户自动定位分析,确保低压停电事件准确性、完整性。%The research of installation load monitoring device in low voltage customer side,real-time acquisition of customer information and the electricity current and voltage data;low voltage module of the new planned outage in the distribution network in the production system,real-time acquisition of low-voltage planned outage events,and advance the SMS notification according to the requirements of customers;through the study on therefinement of GIS topology hierarchy,the realization of "accurate positioning -branch line -door",to realize the automatic positioning analysis of low-voltage power customers,to ensure the accuracy,integrity of low-voltage power outage.

  16. 低压故障停电报警系统%Low Pressure Fault Outage Alarm System

    Institute of Scientific and Technical Information of China (English)

    熊俊锋; 丁月明

    2013-01-01

      供电可靠性要求越来越高,对低压配电线路的供电情况一直缺乏监测,不能随时掌握台变的运行情况,如果台变发生跳闸事故,只能通过用户打电话通知电力部门,经常出现停电后不能得到即时地处理,给用户带来工作、生活的不便,长时间的停电也会带来很大的经济损失。分析发生故障停电后报修不及时的原因和对策,研制了一套低压停电故障报警监测系统,在台变跳闸停电后能够通知电力抢修部门,使故障停电报修的时间尽可能的缩短,有效的减少了故障停电时间,提高了供电可靠性,同时有效地提高了供电企业的优质服务水平。%There is higher demand for supply reliability. There is not enough monitoring of the supply of low-voltage distribution lines, and so we can not keep up operation of bench transformer. If the bench transformer occurs tripping accident, we can notify the power sector only through user's call. If the blackouts are often and can not be immediately treated, it will bring inconveniences to the work and living of the user, and also will bring great economic losses. This paper analyzed the causes and countermeasures for not timely repair to failure blackout, developed a set of low-voltage power failure alarm monitoring system which can send the tripping blackout to electrical repair department, reduce the repair time and effectively reduce the fault outage time, improve the reliability of power supply, at the same time improve the level of quality service of power supply enterprise.

  17. Exact Outage Probability of Dual-Hop CSI-Assisted AF Relaying Over Nakagami-m Fading Channels

    KAUST Repository

    Xia, Minghua

    2012-10-01

    In this correspondence, considering dual-hop channel state information (CSI)-assisted amplify-and-forward (AF) relaying over Nakagami- m fading channels, the cumulative distribution function (CDF) of the end-to-end signal-to-noise ratio (SNR) is derived. In particular, when the fading shape factors m1 and m2 at consecutive hops take non-integer values, the bivariate H-function and G -function are exploited to obtain an exact analytical expression for the CDF. The obtained CDF is then applied to evaluate the outage performance of the system under study. The analytical results of outage probability coincide exactly with Monte-Carlo simulation results and outperform the previously reported upper bounds in the low and medium SNR regions.

  18. Outage Analysis of Train-to-Train Communication Model over Nakagami-m Channel in High-Speed Railway

    Directory of Open Access Journals (Sweden)

    Pengyu Liu

    2013-01-01

    Full Text Available This paper analyzes the end-to-end outage performance of high-speed-railway train-to-train communication model in high-speed railway over independent identical and nonidentical Nakagami-m channels. The train-to-train communication is inter-train communication without an aid of infrastructure (for base station. Source train uses trains on other rail tracks as relays to transmit signals to destination train on the same track. The mechanism of such communication among trains can be divided into three cases based on occurrence of possible-occurrence relay trains. We first present a new closed form for the sum of squared independent Nakagami-m variates and then derive an expression for the outage probability of the identical and non-identical Nakagami-m channels in three cases. In particular, the problem is improved by the proposed formulation that statistic for sum of squared Nakagami-m variates with identical m tends to be infinite. Numerical analysis indicates that the derived analytic results are reasonable and the outage performance is better over Nakagami-m channel in high-speed railway scenarios.

  19. From Multi-Keyholes to Measure of Correlation and Power Imbalance in MIMO Channels: Outage Capacity Analysis

    CERN Document Server

    Levin, George

    2008-01-01

    An information-theoretic analysis of a multi-keyhole channel, which includes a number of statistically independent keyholes with possibly different correlation matrices, is given. When the number of keyholes or/and the number of Tx/Rx antennas is large, there is an equivalent Rayleigh-fading channel such that the outage capacities of both channels are asymptotically equal. In the case of a large number of antennas and for a broad class of fading distributions, the outage capacity is shown to be asymptotically Gaussian in distribution, and compact, closed-form expressions for the mean and variance are given. Motivated by the asymptotic analysis, a simple, full-ordering scalar measure of spatial correlation and power imbalance in MIMO channels is introduced, which quantifies the negative impact of these two factors on the outage capacity in a simple and well-tractable way. It does not require the eigenvalue decomposition, and has the full-ordering property. The size-asymptotic results are used to prove Telatar'...

  20. Outage Performance Analysis of Relay Selection Schemes in Wireless Energy Harvesting Cooperative Networks over Non-Identical Rayleigh Fading Channels.

    Science.gov (United States)

    Do, Nhu Tri; Bao, Vo Nguyen Quoc; An, Beongku

    2016-02-26

    In this paper, we study relay selection in decode-and-forward wireless energy harvesting cooperative networks. In contrast to conventional cooperative networks, the relays harvest energy from the source's radio-frequency radiation and then use that energy to forward the source information. Considering power splitting receiver architecture used at relays to harvest energy, we are concerned with the performance of two popular relay selection schemes, namely, partial relay selection (PRS) scheme and optimal relay selection (ORS) scheme. In particular, we analyze the system performance in terms of outage probability (OP) over independent and non-identical (i.n.i.d.) Rayleigh fading channels. We derive the closed-form approximations for the system outage probabilities of both schemes and validate the analysis by the Monte-Carlo simulation. The numerical results provide comprehensive performance comparison between the PRS and ORS schemes and reveal the effect of wireless energy harvesting on the outage performances of both schemes. Additionally, we also show the advantages and drawbacks of the wireless energy harvesting cooperative networks and compare to the conventional cooperative networks.

  1. Intermediate report of MoReMo. Modelling resilience for maintenance and outage

    Energy Technology Data Exchange (ETDEWEB)

    Oedewald, P.; Macchi, L. (VTT Technical Research Centre of Finland (Finland)); Axelsson, C. (Ringhals AB, Vattenfall AB (Sweden)); Eitrheim, M.H.R. (Institute for Energy Technology (Norway))

    2012-02-15

    Resilience Engineering (RE) is a new approach to safety that helps organisations and individuals adapt to unforeseen events and long-term changes. Such an approach is needed by nuclear power plants (NPPs) as they face demanding modification projects, high staff turnover and increased pressures to maintain and improve safety. The goal of the Modelling Resilience for Maintenance and Outage (MoReMO) project is to develop and test models and methods to identify and analyse resilience in safety-critical activities in natural everyday settings. In 2011, we have applied four approaches in different case studies: Organisational Core Task modelling (OCT), Functional Resonance Analysis Method (FRAM), Efficiency Thoroughness Trade-Off (ETTO) analysis, and Work Practice and Culture Characterisation. The project has collected data through observations, interviews and document reviews at two NPPs. Together, the four approaches have provided valuable insights for understanding the rationale behind work practices, their effects on safety, and the support of flexibility and adaptability. In 2012, the MoReMO project will complete the data collection and integrate results on how resilience can be operationalized in practical safety management tools for the companies. (Author)

  2. Outages threaten competitiveness of utility companies; Systemausfaelle bedrohen Wettbewerbschancen von Energieversorgern

    Energy Technology Data Exchange (ETDEWEB)

    Krebs, A. [Global Switch FM GmbH, Frankfurt (Germany)

    2003-11-03

    In terms of deregulation and growing competition increased customer orientation is decisive for utility companies. For today's energy suppliers, economic success depends to a great extent on services and presentation. This development made Customer Relationship Management (CRM) with the appropriate software solutions a significant instrument. Beside the strategic realization the software tools must work and business continuity is crucial. For utility companies a secure IT-housing is highly important. A special facility equipment provides protection against outages and secures lasting success. (orig.) [German] Im Zeichen von Deregulierung und verschaerftem Wettbewerb ist in der Enegiewirtschaft erhoehte Kundenorientierung gefragt. Energieversorger beziehen ihren Erfolg zum grossen Teil aus Serviceleistungen und dem Auftritt gegenueber dem Kunden. Diese Entwicklung hat Customer Relationship Management (CRM) und die zugehoerigen Softwareloesungen zu einem wichtigen Instrument werden lassen. Damit neben der stategischen Umsetzung auch die modernen Softwaretools funktionieren, muss ein kontinuierlicher Geschaeftsbetrieb gewaehrleistet sein. Eine sichere Unterbringung von Rechenzentren ist fuer Energieversorger zur Erhaltung ihrer Wettbewerbsfaehigkeit von enormer Wichtigkeit. IT-gerechte Gebaeudetechnik bietet Schutz vor Ausfaellen und sichert so dauerhaften Erfolg. (orig.)

  3. Method for Evaluation of Outage Probability on Random Access Channel in Mobile Communication Systems

    Science.gov (United States)

    Kollár, Martin

    2012-05-01

    In order to access the cell in all mobile communication technologies a so called random-access procedure is used. For example in GSM this is represented by sending the CHANNEL REQUEST message from Mobile Station (MS) to Base Transceiver Station (BTS) which is consequently forwarded as an CHANNEL REQUIRED message to the Base Station Controller (BSC). If the BTS decodes some noise on the Random Access Channel (RACH) as random access by mistake (so- called ‘phantom RACH') then it is a question of pure coincidence which èstablishment cause’ the BTS thinks to have recognized. A typical invalid channel access request or phantom RACH is characterized by an IMMEDIATE ASSIGNMENT procedure (assignment of an SDCCH or TCH) which is not followed by sending an ESTABLISH INDICATION from MS to BTS. In this paper a mathematical model for evaluation of the Power RACH Busy Threshold (RACHBT) in order to guaranty in advance determined outage probability on RACH is described and discussed as well. It focuses on Global System for Mobile Communications (GSM) however the obtained results can be generalized on remaining mobile technologies (ie WCDMA and LTE).

  4. Optimal PMU placement for maintaining full network observability during single outage of lines

    Directory of Open Access Journals (Sweden)

    Fariborz Haghighatdar fesharaki

    2011-05-01

    Full Text Available Nowadays, the optimal application of phasor measurement units (PMUs in power systems is increasing because of their advantages such as the capability for dynamical state estimation and improvements in the speed of control and protection systems. In this paper, a new method is presented using binary integer linear programming for the optimal placement of PMUs to guarantee full observability of a power system. Moreover, the problem of the optimal placement of these units in the case of a single line outage is investigated. In all of the investigations, the effect of zero-injection buses in the power system was considered. The ability of the proposed method in solving any of these problems was demonstrated by applying to the 14-, 30-, 39-, 57- and 118-bus IEEE standard systems, 42-bus transmission network of Esfahan Regional Electric and also two very large-scale systems with 2383 and 2746 buses. The simulation results verified the effective and appropriate performance of the proposed method in comparison with other methods.

  5. BER and Outage Probability Approximations for LMMSE Detectors on Correlated MIMO Channels

    CERN Document Server

    Kammoun, Abla; Hachem, Walid; Najim, Jamal

    2008-01-01

    This paper is devoted to the study of the performance of the Linear Minimum Mean-Square Error receiver for (receive) correlated Multiple-Input Multiple-Output systems. By the random matrix theory, it is well-known that the Signal-to-Noise Ratio (SNR) at the output of this receiver behaves asymptotically like a Gaussian random variable as the number of receive and transmit antennas converge to +$\\infty$ at the same rate. However, this approximation being inaccurate for the estimation of some performance metrics such as the Bit Error Rate and the outage probability, especially for small system dimensions, Li et al. proposed convincingly to assume that the SNR follows a generalized Gamma distribution which parameters are tuned by computing the first three asymptotic moments of the SNR. In this article, this technique is generalized to (receive) correlated channels, and closed-form expressions for the first three asymptotic moments of the SNR are provided. To obtain these results, a random matrix theory technique...

  6. On the Efficient Simulation of Outage Probability in a Log-normal Fading Environment

    KAUST Repository

    Rached, Nadhir Ben

    2017-02-15

    The outage probability (OP) of the signal-to-interference-plus-noise ratio (SINR) is an important metric that is used to evaluate the performance of wireless systems. One difficulty toward assessing the OP is that, in realistic scenarios, closed-form expressions cannot be derived. This is for instance the case of the Log-normal environment, in which evaluating the OP of the SINR amounts to computing the probability that a sum of correlated Log-normal variates exceeds a given threshold. Since such a probability does not admit a closed-form expression, it has thus far been evaluated by several approximation techniques, the accuracies of which are not guaranteed in the region of small OPs. For these regions, simulation techniques based on variance reduction algorithms is a good alternative, being quick and highly accurate for estimating rare event probabilities. This constitutes the major motivation behind our work. More specifically, we propose a generalized hybrid importance sampling scheme, based on a combination of a mean shifting and a covariance matrix scaling, to evaluate the OP of the SINR in a Log-normal environment. We further our analysis by providing a detailed study of two particular cases. Finally, the performance of these techniques is performed both theoretically and through various simulation results.

  7. Outage and ser performance of spectrum sharing system with TAS/MRC

    KAUST Repository

    Khan, Fahd Ahmed

    2013-06-01

    Capacity of the secondary network degrades due to the interference constraint from the primary network. The secondary network capacity can be enhanced by means of spatial diversity, that can be achieved by adding multiple antennas on the terminals. In this paper, the performance of a multiple-input multiple-output (MIMO) secondary link with transmit antenna selection (TAS) at the transmitter and maximum ratio combining (MRC) at the receiver is analysed. A peak transmit power constraint is considered in addition to the interference power constraint. For a Rayleigh faded channel, closed-form expression for the outage probability of a MIMO cognitive system (MIMO-CS) with TAS/MRC is derived. In addition, closed-form expressions of the moment generating function and the symbol error rate are also obtained. The performance of this system is analyzed for asymptotic regimes and it is shown that TAS/MRC in a MIMO-CS achieves a generalized diversity order of nTnR, where nT and nR are the number of transmit and receive antennas, respectively. Numerical results are also presented to corroborate the derived analytical results. © 2013 IEEE.

  8. The Application of Phasor Measurement Units in Transmission Line Outage Detection Using Support Vector Machine

    Directory of Open Access Journals (Sweden)

    A. Y. Abdelaziz

    2013-07-01

    Full Text Available Many protection applications are based upon the Phasor Measurement Units (PMUs technology. Therefore, PMUs have been increasingly widespread throughout the power network, and there are several researches have been made to locate the PMUs for complete system observability. This paper introduces an important application of PMUs in power system protection which is the detection of single line outage. In addition, a detection of the out of service line is achieved depending on the variations of phase angles measured at the system buses where the PMUs are located. Hence, a protection scheme from unexpected overloading in the network that may lead to system collapse can be achieved. Such detections are based upon an artificial intelligence technique which is the support Vector Machine (SVM classification tool. To demonstrate the effectiveness of the proposed approach, the algorithm is tested using offline simulation for both the 14-bus IEEE and the 30-bus IEEE systems. Two different kernels of the SVM are tested to select the more appropriate one (i.e. polynomial and Radial Basis Function (RBF kernels are used.

  9. Feasibility Analysis of Technology on Storage Battery for Non-outage Maintenance in Distribution Network%以蓄电池作配电网不停电作业电源的技术可行性分析

    Institute of Scientific and Technical Information of China (English)

    唐龙江; 胡海琴; 汪宏华

    2013-01-01

      The development of portable power source technology is firstly introduced and a new power source technology based on storage battery for non-outage maintenance is presented. By analyzing the relationship of battery amount, power supply time and capacity, the applicable scope is then studied. The non-outage maintenance for outage accidents of Huangshan distribution grid are used to check the feasibility and economic efficiency of the technology presented preliminarily. The result shows that technology is useful for non-outage maintenance of distribution grid and, it has the advantage of wide application scope and flexibility. With the development of storage battery and electric vehicle technology, the technology presented will be more economical and practical in the near future.%  介绍了移动电源技术的发展情况,提出了一种以蓄电池作不停电作业电源的新技术,分析了电池组数与供电时间及供电容量的关系,研究了该技术的适用范围,并以黄山电网的两起典型配网停电事故的不停电检修作为算例,对蓄电池作配电网不停电检修电源技术的可行性及经济性进行了验证。结果表明:蓄电池作不停电作业电源技术适宜在配电网不停电检修中应用,且该技术适用范围广,灵活性优势明显。今后随着蓄电池和电动汽车技术的发展,该技术的应用将更为经济、实用。

  10. VORBrouter: A dynamic data routing system for Real-Time Seismic networks

    Science.gov (United States)

    Hansen, T.; Vernon, F.; Lindquist, K.; Orcutt, J.

    2004-12-01

    For anyone who has managed a moderately complex buffered real-time data transport system, the need for reliable adaptive data transport is clear. The ROADNet VORBrouter system, an extension to the ROADNet data catalog system [AGU-2003, Dynamic Dataflow Topology Monitoring for Real-time Seismic Networks], allows dynamic routing of real-time seismic data from sensor to end-user. Traditional networks consist of a series of data buffer computers with data transport interconnections configured by hand. This allows for arbitrarily complex data networks, which can often exceed full comprehension by network administrators, sometimes resulting in data loops or accidental data cutoff. In order to manage data transport systems in the event of a network failure, a network administrator must be called upon to change the data transport paths and to recover the missing data. Using VORBrouter, administrators can sleep at night while still providing 7/24 uninterupted data streams at realistic cost. This software package uses information from the ROADNet data catalog system to route packets around failed link outages and to new consumers in real-time. Dynamic data routing protocols operating on top of the Antelope Data buffering layer allow authorized users to request data sets from their local buffer and to have them delivered from anywhere within the network of buffers. The VORBrouter software also allows for dynamic routing around network outages, and the elimination of duplicate data paths within the network, while maintaining the nearly lossless data transport features exhibited by the underlying Antelope system. We present the design of the VORBrouter system, its features, limitations and some future research directions.

  11. 38 CFR 21.4145 - Work-study allowance.

    Science.gov (United States)

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Work-study allowance. 21...; Educational Assistance Allowance § 21.4145 Work-study allowance. (a) Eligibility. (1) A veteran or reservist... rate of three-quarter time or full time is eligible to receive a work-study allowance. (2) An...

  12. HOSPITAL "LARGE-SCALE POWER OUTAGES," SCENARIO DESIGN AND COUNTERMEASURES%医院"大范围停电"情景构建及对策研究

    Institute of Scientific and Technical Information of China (English)

    程勇; 蔡建强; 王兴宇; 胡建华

    2015-01-01

    文章介绍了中国医学科学院肿瘤医院的供电系统概况;针对发生大范围停电的几种可能性,制订了针对四种情况的处置方法;列举了应对"大范围停电"需要准备的物资;阐述了针对"大范围停电"情景演练的意义.%The article briefly introduces the power supply system of Chinese Academy of Medical Sciences Cancer Hospital; developed disposal measures for the four possibilities for large-scale power outage; listed materials need to prepare for the "large-scale power outages"; elaborated the significance of the "large-scale power outages" dril.

  13. Vietnam recommended dietary allowances 2007.

    Science.gov (United States)

    Khan, Nguyen Cong; Hoan, Pham Van

    2008-01-01

    It has been well acknowledged that Vietnam is undergoing a nutrition transition. With a rapid change in the country's reform and economic growth, food supply at the macronutrient level has improved. Changes of the Vietnamese diet include significantly more foods of animal origin, and an increase of fat/oils, and ripe fruits. Consequently, nutritional problems in Vietnam now include not only malnutrition but also overweight/obesity, metabolic syndrome and other chronic diseases related to nutrition and lifestyles. The recognition of these shifts, which is also associated with morbidity and mortality, was a major factor in the need to review and update the Recommended Dietary Allowances (RDA) for the Vietnamese population. This revised RDA established an important science-based tool for evaluation of nutrition adequacy, for teaching, and for scientific communications within Vietnam. It is expected that the 2007 Vietnam RDA and its conversion to food-based dietary guidelines will facilitate education to the public, as well as the policy implementation of programs for prevention of non-communicable chronic diseases and addressing the double burden of both under and over nutrition.

  14. Exact closed form expressions for outage probability of GSC receivers over Rayleigh fading channel subject to self-interference

    KAUST Repository

    Nam, Sungsik

    2010-11-01

    Previous work on performance analyses of generalized selection combining (GSC) RAKE receivers based on the signal to noise ratio focused on the development of methodologies to derive exact closed-form expressions for various performance measures. However, some open problems related to the performance evaluation of GSC RAKE receivers still remain to be solved such that an assessment of the impact of self-interference on the performance of GSC RAKE receivers. To have a full and exact understanding of the performance of GSC RAKE receivers, the outage probability of GSC RAKE receivers needs to be analyzed as closed-form expressions. The major difficulty in this problem is to derive some joint statistics of ordered exponential variates. With this motivation in mind, we capitalize in this paper on some new order statistics results to derive exact closed-form expressions for outage probability of GSC RAKE receivers subject to self-interference over independent and identically distributed Rayleigh fading channels. © 2010 IEEE.

  15. Cooperative AF Relaying in Spectrum-Sharing Systems: Outage Probability Analysis under Co-Channel Interferences and Relay Selection

    KAUST Repository

    Xia, Minghua

    2012-11-01

    For cooperative amplify-and-forward (AF) relaying in spectrum-sharing wireless systems, secondary users share spectrum resources originally licensed to primary users to communicate with each other and, thus, the transmit power of secondary transmitters is strictly limited by the tolerable interference powers at primary receivers. Furthermore, the received signals at a relay and at a secondary receiver are inevitably interfered by the signals from primary transmitters. These co-channel interferences (CCIs) from concurrent primary transmission can significantly degrade the performance of secondary transmission. This paper studies the effect of CCIs on outage probability of the secondary link in a spectrum-sharing environment. In particular, in order to compensate the performance loss due to CCIs, the transmit powers of a secondary transmitter and its relaying node are respectively optimized with respect to both the tolerable interference powers at the primary receivers and the CCIs from the primary transmitters. Moreover, when multiple relays are available, the technique of opportunistic relay selection is exploited to further improve system performance with low implementation complexity. By analyzing lower and upper bounds on the outage probability of the secondary system, this study reveals that it is the tolerable interference powers at primary receivers that dominate the system performance, rather than the CCIs from primary transmitters. System designers will benefit from this result in planning and designing next-generation broadband spectrum-sharing systems.

  16. High-Rate Communications Outage Recorder Operations for Optimal Payload and Science Telemetry Management Onboard the International Space Station

    Science.gov (United States)

    Shell, Michael T.; McElyea, Richard M. (Technical Monitor)

    2002-01-01

    All International Space Station (ISS) Ku-band telemetry transmits through the High-Rate Communications Outage Recorder (HCOR). The HCOR provides the recording and playback capability for all payload, science, and International Partner data streams transmitting through NASA's Ku-band antenna system. The HCOR is a solid-state memory recorder that provides recording capability to record all eight ISS high-rate data during ISS Loss-of-Signal periods. NASA payloads in the Destiny module are prime users of the HCOR; however, NASDA and ESA will also utilize the HCOR for data capture and playback of their high data rate links from the Kibo and Columbus modules. Marshall Space Flight Center's Payload Operations Integration Center manages the HCOR for nominal functions, including system configurations and playback operations. The purpose of this paper is to present the nominal operations plan for the HCOR and the plans for handling contingency operations affecting payload operations. In addition, the paper will address HCOR operation limitations and the expected effects on payload operations. The HCOR is manifested for ISS delivery on flight 9A with the HCOR backup manifested on flight 11A. The HCOR replaces the Medium-Rate Communications Outage Recorder (MCOR), which has supported payloads since flight 5A.1.

  17. Power Control and Performance Analysis of Outage-Limited Cellular Network with MUD-SIC and Macro-Diversity

    CERN Document Server

    Ng, Derrick Wing Kwan

    2010-01-01

    In this paper, we analyze the uplink goodput (bits/sec/Hz successfully decoded) and per-user packet outage in a cellular network using multi-user detection with successive interference cancellation (MUD-SIC). We consider non-ergodic fading channels where microscopic fading channel information is not available at the transmitters. As a result, packet outage occurs whenever the data rate of packet transmissions exceeds the instantaneous mutual information even if powerful channel coding is applied for protection. We are interested to study the role of macro-diversity (MDiv) between multiple base stations on the MUD-SIC performance where the effect of potential error-propagation during the SIC processing is taken into account. While the jointly optimal power and decoding order in the MUD-SIC are NP hard problem, we derive a simple on/off power control and asymptotically optimal decoding order with respect to the transmit power. Based on the information theoretical framework, we derive the closed-form expressions...

  18. Operational readiness verification, phase 1: A study on safety during outage and restart of nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Hollnagel, E. [Linkoeping Univ. (Sweden). Dept. of Computer and Information Science; Gauthereau, V. [Linkoeping Univ. (Sweden). Dept. of Industrial Engineering

    2001-06-01

    This report contains the findings from the first phase of a study on safety during outage and restart of nuclear power plants. Operational Readiness Verification (ORV) - in Swedish called Driftklarhetsverifiering (DKV) - refers to the test and verification activities that are necessary to ensure that plant systems are able to provide their required functions when needed - more concretely that all plant systems are in their correct functional state when the plant is restarted after an outage period. The concrete background for this work is that nine ORV related incidents were reported in Sweden between July 1995 and October 1998. The work reported here comprised a literature survey of research relevant for ORV issues, and an assessment of the present situation at Swedish NPPs with respect to ORV. The literature survey was primarily aimed at research related to NPPs, but also looked at domains where similar problems have occurred, such as maintenance in commercial aviation. The survey looked specifically for organisational and MTO aspects relevant to the present situation in Swedish NPPs. One finding was that ORV should be seen as an integral part of maintenance, rather than as a separate activity. Another, that there is a characteristic distribution of error modes for maintenance and ORV, with many sequence errors and omissions, rather than a set of unique error modes. An international study further showed that there are important differences in how procedures are used, and in the balance between decentralisation and centralisation. Several studies also suggested that ORV could usefully be described as a barrier system in relation to the flow of work, for instance using the following five stages: (1) preventive actions during maintenance/outage, (2) post-test after completion of work, (3) pre-test before start-up, (4) the start-up sequence itself, and (5) preventive actions during power operation - possibly including automatic safety systems. In the field survey

  19. Transformation of serum-susceptible Escherichia coli O111 with p16Slux plasmid to allow for real-time monitoring of complement-based inactivation of bacterial growth in bovine milk.

    Science.gov (United States)

    Maye, S; Stanton, C; Fitzgerald, G F; Kelly, P M

    2016-01-01

    Complement activity has only recently been characterized in raw bovine milk. However, the activity of this component of the innate immune system was found to diminish as milk was subjected to heat or partitioning during cream separation. Detection of complement in milk relies on a bactericidal assay. This assay exploits the specific growth susceptibility of Escherichia coli O111 to the presence of complement. Practical application of the assay was demonstrated when a reduction in complement activity was recorded in the case of pasteurized and reduced-fat milks. This presented an opportunity to improve the functionality of the bactericidal assay by incorporating bioluminescence capability into the target organism. Following some adaptation, the strain was transformed by correctly integrating the p16Slux plasmid. Growth properties of the transformed strain of E. coli O111 were unaffected by the modification. The efficacy of the strain adaptation was correlated using the LINEST function analysis [r=0.966; standard error of prediction (SEy)=0.957] bioluminescence with that of bactericidal assay total plate counts within the range of 7.5 to 9.2 log cfu/mL using a combination of raw and processed milk samples. Importantly, the transformed E. coli O111 p16Slux strain could be identified in milk and broth samples using bioluminescence measurement, thus enabling the bactericidal assay-viability test to be monitored in real time throughout incubation.

  20. 山火条件下的架空输电线路停运概率模型%A Probabilistic Model of Overhead Transmission Line Outage due to Forest Fire

    Institute of Scientific and Technical Information of China (English)

    宋嘉婧; 郭创新; 张金江; 王越; 盛鹍

    2013-01-01

    Some overhead transmission corridors pass through fire-prone regions such as mountain and rural areas, and forest fire greatly affects on transmission line reliability. At present, in the research on reliability model of overhead transmission line the condition of forest fire is seldom taken into account. Utilizing mathematical model of surface fire behavior caused by forest fire, the forest fire conditions obtained from this model are taken as input variables and led into the computation of reliability of overhead transmission line. Based on the reasons causing breakdown of air gap of overhead transmission line, corresponding probabilistic model of overhead transmission line outage is built, in which the air gap breakdown mechanism under forest fire is considered, to predict the outage probability due to phase-to-ground discharge and that due to phase-to-phase discharge. In case studies the affected times of overhead transmission line operation after the occurrence of forest fire are calculated and the outage probabilities of typical overhead transmission line under different forest fire conditions are given. Calculation results show that the proposed model can reflect the affect of forest fire on overhead transmission line reliability correctly.%由于输电走廊经常经过山区、农区等山火易发地带,山火已对输电线路可靠性产生重要影响.目前考虑山火状况对输电线路可靠性模型方面的研究较少,为此,以山火地表火行为数理模型为基础,将模型得出的山火状况作为输入量,引入输电线路可靠性计算中.基于山火导致输电线路空气间隙被击穿的原因,建立了相应的停运概率模型,预测相地放电与相间放电2种情况的停运概率.算例计算了某山火发生后将影响到线路运行的时间,并给出了典型的输电线路在不同山火状态下的停运概率,结果表明模型能够正确反映山火对输电线路可靠性的影响.

  1. Evaluation of the resilience of a full-scale down-flow hanging sponge reactor to long-term outages at a sewage treatment plant in India.

    Science.gov (United States)

    Onodera, Takashi; Takayama, Daisuke; Ohashi, Akiyoshi; Yamaguchi, Takashi; Uemura, Shigeki; Harada, Hideki

    2016-10-01

    Resilience to process outages is an essential requirement for sustainable wastewater treatment systems in developing countries. In this study, we evaluated the ability of a full-scale down-flow hanging sponge (DHS) reactor to recover after a 10-day outage. The DHS tested in this study uses polyurethane sponge as packing material. This full-scale DHS reactor has been tested over a period of about 4 years in India with a flow rate of 500 m(3)/day. Water was not supplied to the DHS reactor that was subjected to the 10-day outage; however, the biomass did not dry out because the sponge was able to retain enough water. Soon after the reactor was restarted, a small quantity of biomass, amounting to only 0.1% of the total retained biomass, was eluted. The DHS effluent achieved satisfactory removal of suspended solids, chemical oxygen demand, and ammonium nitrogen within 90, 45, and 90 min, respectively. Conversely, fecal coliforms in the DHS effluent did not reach satisfactory levels within 540 min; instead, the normal levels of fecal coliforms were achieved within 3 days. Overall, the tests demonstrated that the DHS reactor was sufficiently robust to withstand long-term outages and achieved steady state soon after restart. This reinforces the suitability of this technology for developing countries.

  2. The Fixed-Bias Langmuir Probe on the Communication-Navigation Outage Forecast System Satellite: Calibration and Validation

    Science.gov (United States)

    Klenzing, J.; Rowland, D.

    2012-01-01

    A fixed-bias spherical Langmuir probe is included as part of the Vector Electric Field Instrument (VEFI) suite on the Communication Navigation Outage Forecast System (CNOFS) satellite.CNOFS gathers data in the equatorial ionosphere between 400 and 860 km, where the primary constituent ions are H+ and O+. The ion current collected by the probe surface per unit plasma density is found to be a strong function of ion composition. The calibration of the collected current to an absolute density is discussed, and the performance of the spherical probe is compared to other in situ instruments on board the CNOFS satellite. The application of the calibration is discussed with respect to future fixed-bias probes; in particular, it is demonstrated that some density fluctuations will be suppressed in the collected current if the plasma composition rapidly changes along with density. This is illustrated in the observation of plasma density enhancements on CNOFS.

  3. Estimation of Outage Capacity for Free Space Optical Links Over I-K and K Turbulent Channels

    Directory of Open Access Journals (Sweden)

    D. Marinos

    2011-06-01

    Full Text Available The free space optical communication systems are attracting great research and commercial interest due to their capability of transferring data, over short distances, with high rate and security, low cost demands and without licensing fees. However, their performance depends strongly on the atmospheric conditions in the link’s area. In this work, we investigate the influence of the turbulence on the outage capacity of such a system for weak to strong turbulence channels modeled by the I-K and the K-distribution and we derive closed-form expressions for its estimation. Finally, using these expressions we present numerical results for various link cases with different turbulence conditions.

  4. Lightning-Generated Whistler Waves Observed by Probes On The Communication/Navigation Outage Forecast System Satellite at Low Latitudes

    Science.gov (United States)

    Holzworth, R. H.; McCarthy, M. P.; Pfaff, R. F.; Jacobson, A. R.; Willcockson, W. L.; Rowland, D. E.

    2011-01-01

    Direct evidence is presented for a causal relationship between lightning and strong electric field transients inside equatorial ionospheric density depletions. In fact, these whistler mode plasma waves may be the dominant electric field signal within such depletions. Optical lightning data from the Communication/Navigation Outage Forecast System (C/NOFS) satellite and global lightning location information from the World Wide Lightning Location Network are presented as independent verification that these electric field transients are caused by lightning. The electric field instrument on C/NOFS routinely measures lightning ]related electric field wave packets or sferics, associated with simultaneous measurements of optical flashes at all altitudes encountered by the satellite (401.867 km). Lightning ]generated whistler waves have abundant access to the topside ionosphere, even close to the magnetic equator.

  5. Power allocation and achievable data rate in spectrum-sharing channels under adaptive primary service outage constraints

    KAUST Repository

    Yang, Yuli

    2012-09-01

    In this paper, we focus on a cognitive radio network where adaptive modulation is adopted in primary links. The gap between the primary user (PU)\\'s received signal-to-noise ratio (SNR) and the lower SNR boundary of the modulation mode that is being used, provides an interference-tolerable zone. Based on this gap, a secondary user (SU) has an increased opportunity to access the licensed spectrum and to determine the transmit power it should use to keep the PU\\'s quality-of-service (QoS) unaffected. However, since the SU cannot obtain perfect information on the PU\\'s received SNR, it has to choose an SNR point between the lower and upper boundaries of the PU\\'s current modulation mode as if this point were the real SNR received by the PU. Considering this issue, in order to quantify the effect of the SU\\'s transmissions on the PU\\'s QoS, we define the PU\\'s service outage probability and obtain its closed-form expressions by taking into account whether the peak transmit power constraint is imposed on the secondary\\'s transmission or not. Subsequently, we derive the SU\\'s achievable data rate in closed form for counterpart scenarios. Numerical results provided here quantify the relation between the PU\\'s service outage probability and the SU\\'s achievable data rate, which further demonstrate that the higher the peak transmit power a secondary transmitter can support, the better performance the cognitive radio network can achieve. © 2012 IEEE.

  6. Research on estimation method of customer outage cost in distribution network based on the reliability%基于可靠性的配电网用户停电损失估算方法研究

    Institute of Scientific and Technical Information of China (English)

    万东; 张忠会

    2015-01-01

    Based on the reliability, this paper presents a kind of estimation method integrating customer damage func-tion.The outage loss of customers in each type in the time of peak load is acquired based on the method of customer survey .Taking the factors such as the energy consumption ratio and load rating of various users into account, the com-posite function of the outage loss of customers is set up.The estimation method is proposed based on the effects of the reliability to users made by the elements in the different positions on the line.This method can provide a reference for the engineers to make economic decisions about network planning and construction.Finally, the test system of IEEE RBTS is used to illustrate the feasibility and effectiveness of this method.%提出了一种综合用户停电损失函数和基于可靠性计算的用户停电损失估算方法。文章以用户调查方法为基础,获得峰荷状态下各类用户的停电损失,同时考虑各类用户的用电量比例和负荷率等因素,建立综合用户停电损失函数。根据元件在线路上不同位置对用户可靠性的影响,提出了用户停电损失的估算方法。该方法对工程人员进行电网规划和建设时的经济决策具有一定的参考作用。最后,以IEEE RBTS为例说明了该方法的可行性和有效性。

  7. 基于运行可靠性模型的连锁故障模拟及薄弱环节分析%The Power System Cascading Outage Simulation and Vulnerability Analysis Based on Operational Reliability Model

    Institute of Scientific and Technical Information of China (English)

    程林; 刘满君; 易俊; 何剑; 贺庆

    2016-01-01

    提出一种基于运行可靠性模型的连锁故障模拟及系统薄弱环节分析方法。该方法结合影响连锁故障各个阶段的关键因素不同,将触发事件与后继发展事件独立,建立发现触发事件的初始故障概率模型,并重点分析后继发展事件的传播特性;其中,根据线路运行可靠性模型,考虑在连锁故障快速发展阶段系统潮流变化对线路停运的影响,从而发现后续发展事件以及连锁故障事件间的相关性;结合运行可靠性模型,搜索系统在不同初始故障下的连锁故障事件,并形成连锁故障事件集;基于连锁故障事件集分析系统薄弱环节及事件相关性,发现系统关键元件。结合算例,通过模拟系统在不同初始故障下的连锁故障事件并分析系统薄弱环节,可以提出相应的系统改造方案,预防连锁故障发生,并可以在事件发展过程中发现后继事件,以便阻止连锁事件进一步演化发展。%This paper proposed a power system cascading outage simulation and vulnerability analysis method based on an operational reliability model. This method firstly considered different factors in different cascading outage stages, and then classified outage events into initial outage and subsequent outage, an initial outage model was given and subsequent outage property was highlighted later. Based on the operational reliability model, impact of load level on transmission lines was taken into consideration in fast outage stage. This model could be used to analyze subsequent outages and interactions between outage events. Cascading outage events for different initial outages were simulated and vulnerability analysis was presented to locate critical component of power system. Case study results showed that this method could simulate cascading outages for different initial outages and find out vulnerable components of power system, some more system improvement measures

  8. 46 CFR 154.421 - Allowable stress.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Allowable stress. 154.421 Section 154.421 Shipping COAST... § 154.421 Allowable stress. The allowable stress for the integral tank structure must meet the American Bureau of Shipping's allowable stress for the vessel's hull published in “Rules for Building and...

  9. 46 CFR 154.440 - Allowable stress.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Allowable stress. 154.440 Section 154.440 Shipping COAST... Tank Type A § 154.440 Allowable stress. (a) The allowable stresses for an independent tank type A must... Commandant (CG-522). (b) A greater allowable stress than required in paragraph (a)(1) of this section may...

  10. Imprecise Estimation for Conditional Outage Probabilities of Power Components%电力设备停运概率的非精确条件估计

    Institute of Scientific and Technical Information of China (English)

    刁浩然; 杨明; 韩学山; 马世英; 刘道伟; 王剑辉

    2016-01-01

    By using limited outage samples, it is difficult to obtain the operational reliability indexes of power components accurately. Therefore, estimating the fluctuation ranges of the indexes can provide a more objective decision-making basis for power system operational risk control. In this paper, a novel approach was proposed to estimate the imprecise conditional outage probabilities of power components based on the credal network (CN), which could evaluate the interval ranges of conditional probabilities. Based on the historical outage statistics and the component operational conditions at the target period, a credal network, which used the imprecise Dirichlet model (IDM) to get the imprecise probabilistic dependencies, was set up to estimate the imprecise conditional outage probabilities. Therefore, the imprecise outage probabilities of components can be obtained by using the reasoning algorithm of the credal network. The proposed approach can reflect the variation of the conditional outage probabilities with respected to the operational conditions of the power components, and breaks a new way for the reliability assessment of power components with limited outage observations. Results on estimating the imprecise conditional outage probabilities of LGJ-300 transmission lines located in Shandong province illustrate the effectiveness of the proposed approach.%在小样本条件下,电力设备的运行可靠性参数难以精确获取,对其波动范围进行估计,可为电力系统运行提供更为客观、全面的评估与决策依据。由此,该文提出了一种基于信度网络(credal network, CN)的电力设备停运概率的非精确条件估计方法,对暴露型设备运行中条件相依的停运概率指标的区间范围进行估计。该方法基于设备停运的历史统计数据和估计目标时段的运行工况条件,构建了处理非精确条件概率推断问题的信度网络,并利用多状态随机变量的

  11. Analysis and Mitigation of Tropospheric Effects on Ka Band Satellite Signals and Estimation of Ergodic Capacity and Outage Probability for Terrestrial Links

    OpenAIRE

    Enserink, Scott Warren

    2012-01-01

    The first part of this work covers the effect of the troposphere onKa band (20-30 GHz) satellite signals. The second part deals withthe estimation of the capacity and outage probability forterrestrial links when constrained to quadrature amplitudemodulations.The desire for higher data rates and the need for availablebandwidth has pushed satellite communications into the Ka band(20-30 GHz). At these higher carrier frequencies the effects ofscintillation and rain attenuation are increased. In...

  12. Allowance Holdings and Transfers Data Inventory

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Allowance Holdings and Transfers Data Inventory contains measured data on holdings and transactions of allowances under the NOx Budget Trading Program (NBP), a...

  13. Clean Air Markets - Allowances Query Wizard

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Allowances Query Wizard is part of a suite of Clean Air Markets-related tools that are accessible at http://camddataandmaps.epa.gov/gdm/index.cfm. The Allowances...

  14. On the Efficient Simulation of the Distribution of the Sum of Gamma-Gamma Variates with Application to the Outage Probability Evaluation Over Fading Channels

    KAUST Repository

    Chaouki Ben Issaid

    2016-06-01

    The Gamma-Gamma distribution has recently emerged in a number of applications ranging from modeling scattering and reverbation in sonar and radar systems to modeling atmospheric turbulence in wireless optical channels. In this respect, assessing the outage probability achieved by some diversity techniques over this kind of channels is of major practical importance. In many circumstances, this is intimately related to the difficult question of analyzing the statistics of a sum of Gamma-Gamma random variables. Answering this question is not a simple matter. This is essentially because outage probabilities encountered in practice are often very small, and hence the use of classical Monte Carlo methods is not a reasonable choice. This lies behind the main motivation of the present work. In particular, this paper proposes a new approach to estimate the left tail of the sum of Gamma-Gamma variates. More specifically, we propose a mean-shift importance sampling scheme that efficiently evaluates the outage probability of L-branch maximum ratio combining diversity receivers over Gamma-Gamma fading channels. The proposed estimator satisfies the well-known bounded relative error criterion, a well-desired property characterizing the robustness of importance sampling schemes, for both identically and non-identically independent distributed cases. We show the accuracy and the efficiency of our approach compared to naive Monte Carlo via some selected numerical simulations.

  15. A Unified Moment-Based Approach for the Evaluation of the Outage Probability with Noise and Interference

    KAUST Repository

    Rached, Nadhir Ben

    2016-12-05

    In this paper, we develop a novel moment-based approach for the evaluation of the outage probability (OP) in a generalized fading environment with interference and noise. Our method is based on the derivation of a power series expansion of the OP of the signal-to-interference-plus-noise ratio (SINR). It does not necessitate stringent requirements, the only major ones being the existence of a power series expansion of the cumulative distribution function of the desired user power and the knowledge of the cross-moments of the interferers’ powers. The newly derived formula is shown to be applicable for most of the well-practical fading models of the desired user under some assumptions on the parameters of the powers’ distributions. A further advantage of our method is that it is applicable irrespective of the nature of the fading models of the interfering powers, the only requirement being the perfect knowledge of their crossmoments. In order to illustrate the wide scope of applicability of our technique, we present a convergence study of the provided formula for the Generalized Gamma and the Rice fading models. Moreover, we show that our analysis has direct bearing on recent multi-channel applications using selection diversity techniques. Finally, we assess by simulations the accuracy of the proposed formula for various fading environments.

  16. Exact outage analysis of the effect of co-channel interference on secured multi-hop relaying networks

    Science.gov (United States)

    Quang Nguyen, Sang; Kong, Hyung Yun

    2016-11-01

    In this article, the presence of multi-hop relaying, eavesdropper and co-channel interference (CCI) in the same system model is investigated. Specifically, the effect of CCI on a secured multi-hop relaying network is studied, in which the source communicates with the destination via multi-relay-hopping under the presence of an eavesdropper and CCI at each node. The optimal relay at each cluster is selected to help forward the message from the source to the destination. We apply two relay selection approaches to such a system model, i.e. the optimal relay is chosen based on (1) the maximum channel gain from the transmitter to all relays in the desired cluster and (2) the minimum channel gain from the eavesdropper to all relays in each cluster. For the performance evaluation and comparison, we derived the exact closed form of the secrecy outage probability of the two approaches. That analysis is verified by Monte Carlo simulation. Finally, the effects of the number of hops, the transmit power at the source, relays and the external sources, the distance between the external sources and each node in the system, and the location of the eavesdropper are presented and discussed.

  17. Use of carbon monoxide alarms to prevent poisonings during a power outage--North Carolina, December 2002.

    Science.gov (United States)

    2004-03-12

    Each year in the United States, approximately 500 persons die from unintentional carbon monoxide (CO) poisoning, often during electric power outages caused by severe storms. Use of residential CO alarms has been recommended to reduce the incidence of CO poisoning. In September 2000, Mecklenburg County, North Carolina (2002 population: 722,367), adopted a public health ordinance requiring a CO alarm in the majority of residences; all-electric residences without attached garages (35.4% of all homes) were exempt. The ordinance also permitted use of alarms without battery back-up. On December 4, 2002, an ice storm caused 78.9% of county households to lose power. During the next 9 days, 124 cases of symptomatic CO poisoning were reported. To characterize these poisonings and the effectiveness of the CO alarm ordinance, local emergency physicians, fire department authorities, and CDC conducted an investigation. This report summarizes the results of that investigation, which determined that 96.2% of the severe poisonings occurred in homes with no reported functioning CO alarm. As a result of these findings, on October 8, 2003, Mecklenburg County officials amended the ordinance to require alarms with battery back-ups in all residences. Officials in other communities should consider enacting such alarm ordinances to prevent CO poisonings.

  18. An Overview of Scientific and Space Weather Results from the Communication/Navigation Outage Forecasting System (C/NOFS) Mission

    Science.gov (United States)

    Pfaff, R.; de la Beaujardiere, O.; Hunton, D.; Heelis, R.; Earle, G.; Strauss, P.; Bernhardt, P.

    2012-01-01

    The Communication/Navigation Outage Forecasting System (C/NOFS) Mission of the Air Force Research Laboratory is described. C/NOFS science objectives may be organized into three categories: (1) to understand physical processes active in the background ionosphere and thermosphere in which plasma instabilities grow; (2) to identify mechanisms that trigger or quench the plasma irregularities responsible for signal degradation; and (3) to determine how the plasma irregularities affect the propagation of electromagnetic waves. The satellite was launched in April, 2008 into a low inclination (13 deg), elliptical (400 x 850 km) orbit. The satellite sensors measure the following parameters in situ: ambient and fluctuating electron densities, AC and DC electric and magnetic fields, ion drifts and large scale ion composition, ion and electron temperatures, and neutral winds. C/NOFS is also equipped with a GPS occultation receiver and a radio beacon. In addition to the satellite sensors, complementary ground-based measurements, theory, and advanced modeling techniques are also important parts of the mission. We report scientific and space weather highlights of the mission after nearly four years in orbit

  19. 46 CFR 154.447 - Allowable stress.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Allowable stress. 154.447 Section 154.447 Shipping COAST... Tank Type B § 154.447 Allowable stress. (a) An independent tank type B designed from bodies of revolution must have allowable stresses 3 determined by the following formulae: 3 See Appendix B for...

  20. 46 CFR 154.428 - Allowable stress.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Allowable stress. 154.428 Section 154.428 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY STANDARDS FOR... § 154.428 Allowable stress. The membrane tank and the supporting insulation must have allowable...

  1. 基于工作流的拱墅停电管理系统设计与实现%Design and Implementation of Outage Management System based on Workflow

    Institute of Scientific and Technical Information of China (English)

    葛群波; 杨玉山

    2011-01-01

    This paper introduced workflow technology and the current daily outage management of Gongshu Power Supply Bureau. A workflow technology-based outage management approach, described the outage management system design principle. Discussed some concrete implementations such as process design and power outage notifieationAt the end, draw a conclusion that the outage management system is a good solution to solve outage work of Gongshu power supply bureau.%介绍了工作流技术和目前拱墅供电局日常停电管理现状,提出了一种基于工作流技术实现停电管理的方法,阐述了停电管理系统的设计原理,对流程设计、停电通知等具体实现进行了一定的论述,认为停电管理系统是目前一种较好地解决拱墅供电局停电工作的方案.

  2. 基于工作票的输变电停电事件自动集成%Transmission power outage automatic integration based on working-ticket

    Institute of Scientific and Technical Information of China (English)

    王伟能; 邓集; 熊金山; 杨银花

    2016-01-01

    随着电能质量在线监测系统深化应用,输变电停电事件自动集成已成为电能质量在线监测系统核心的管理功能,实现了从源头系统采集数据并能自动生成停电事件。但是,停电事件生成后,还需要人工进行判断和修改停电性质及原因,增加了管理人员工作负担,同时也不能保证对相关事件管理和统计的及时性。该论文从技术路线与架构、数据流向和数据研判等方面介绍了一种基于工作票的输变电停电原因自动集成典型设计,在现有电能质量在线监测系统中实现了停电原因自动集成。%With power quality monitoring system deepening application, transmission power outage automatically inte-grated has become the core of the system management functions, which collects data from the source system and can au-tomatically generate a power outage. However, these manually judgment and modification the nature and reasons for power outages are need after power outage generating, which increases management burden and can not guarantee that the relevant incident management and timeliness of statistics. This paper presents a typical design for transmission pow-er outage automatic integration based on working-ticket, including technological route, data flow, data judging and so on, which realized the causes of power failures automatically integrated in an existing power quality monitoring system.

  3. 分层网络下行中断概率的闭式表达%Closed Expressions of Downlink Outage Probability in Tiered Networks

    Institute of Scientific and Technical Information of China (English)

    张文健; 田茂; 何浩; 沈祖康

    2011-01-01

    针对用边界值形式表示的共信道干扰限制分层网络的下行中断概率不够精确的问题,采用随机几何理论建模网络结构,并在此基础上推导了每层下行中断概率的闭式表达式.首先构建了关于宏小区信号功率和毫微微小区聚合干扰功率的下行接收信干比函数,然后以聚合干扰功率为条件,根据宏小区信号功率的概率分布推导了接收信干比不高于门限值的概率,最后利用聚合干扰功率的概率分布计算条件中断概率的期望值,得到了中断概率闭式表达式.仿真结果表明:当毫微微小区基站发射功率降低3.16 mW(小区平均数为100),或小区平均数减少20个(基站发射功率为100 mW)时,能够分别使宏小区下行中断概率减小约20%或5%.%Since the downlink outage probability expressed with bound value is not precise enough in co-channel interference-limited tiered networks, the stochastic geometry theory is used to model network framework and closed-expressions of per-tier downlink outage probability are derived based on the framework. The received signal to interference ratio (SIR) is formulated as a function of macrocell signal power and femtocell aggregated interference power. Then the probability for received SIR less than a threshold is derived according to the probability distribution of macro-cell signal power in the condition on the aggregated interference power. The downlink outage probability is obtained by applying the probability distribution of aggregated interference power to calculate the expectation of conditioned outage probability. Simulation results show that the downlink outage probability in macrocell reduces about 20% and 5%, respectively, when the femtocell transmit power decreases 3. 16 mW (the number of femtocells is 100 on average) or the number of femtocells decreases 20 on average (the femtocell transmit power is 100 mW).

  4. Component Repair Times Obtained from MSPI Data

    Energy Technology Data Exchange (ETDEWEB)

    Eide, Steven A. [Curtiss-Wright/Scietech, Ketchum, ID (United States); Cadwallader, Lee [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-05-01

    Information concerning times to repair or restore equipment to service given a failure is valuable to probabilistic risk assessments (PRAs). Examples of such uses in modern PRAs include estimation of the probability of failing to restore a failed component within a specified time period (typically tied to recovering a mitigating system before core damage occurs at nuclear power plants) and the determination of mission times for support system initiating event (SSIE) fault tree models. Information on equipment repair or restoration times applicable to PRA modeling is limited and dated for U.S. commercial nuclear power plants. However, the Mitigating Systems Performance Index (MSPI) program covering all U.S. commercial nuclear power plants provides up-to-date information on restoration times for a limited set of component types. This paper describes the MSPI program data available and analyzes the data to obtain median and mean component restoration times as well as non-restoration cumulative probability curves. The MSPI program provides guidance for monitoring both planned and unplanned outages of trains of selected mitigating systems deemed important to safety. For systems included within the MSPI program, plants monitor both train UA and component unreliability (UR) against baseline values. If the combined system UA and UR increases sufficiently above established baseline results (converted to an estimated change in core damage frequency or CDF), a “white” (or worse) indicator is generated for that system. That in turn results in increased oversight by the US Nuclear Regulatory Commission (NRC) and can impact a plant’s insurance rating. Therefore, there is pressure to return MSPI program components to service as soon as possible after a failure occurs. Three sets of unplanned outages might be used to determine the component repair durations desired in this article: all unplanned outages for the train type that includes the component of interest, only

  5. Outage analysis of selective cooperation in underlay cognitive networks with fixed gain relays and primary interference modeling

    KAUST Repository

    Hussain, Syed Imtiaz

    2012-09-01

    Selective cooperation is a well investigated technique in non-cognitive networks for efficient spectrum utilization and performance improvement. However, it is still a nascent topic for underlay cognitive networks. Recently, it was investigated for underlay networks where the secondary nodes were able to adapt their transmit power to always satisfy the interference threshold to the primary users. This is a valid assumption for cellular networks but many non-cellular devices have fixed transmit powers. In this situation, selective cooperation poses a more challenging problem and performs entirely differently. In this paper, we extend our previous work of selective cooperation based on either hop\\'s signal to noise ratio (SNR) with fixed gain and fixed transmit power relays in an underlay cognitive network. This work lacked in considering the primary interference over the cognitive network and presented a rather idealistic analysis. This paper deals with a more realistic system model and includes the effects of primary interference on the secondary transmission. We first derive end-to-end signal to interference and noise ratio (SINR) expression and the related statistics for a dual-hop relay link using asymptotic and approximate approaches. We then derive the statistics of the selected relay link based on maximum end-to-end SINR among the relays satisfying the interference threshold to the primary user. Using this statistics, we derive closed form asymptotic and approximate expressions for the outage probability of the system. Analytical results are verified through simulations. It is concluded that selective cooperation in underlay cognitive networks performs better only in low to medium SNR regions. © 2012 IEEE.

  6. Adaptive Space–Time Coding Using ARQ

    KAUST Repository

    Makki, Behrooz

    2015-09-01

    We study the energy-limited outage probability of the block space-time coding (STC)-based systems utilizing automatic repeat request (ARQ) feedback and adaptive power allocation. Taking the ARQ feedback costs into account, we derive closed-form solutions for the energy-limited optimal power allocation and investigate the diversity gain of different STC-ARQ schemes. In addition, sufficient conditions are derived for the usefulness of ARQ in terms of energy-limited outage probability. The results show that, for a large range of feedback costs, the energy efficiency is substantially improved by the combination of ARQ and STC techniques if optimal power allocation is utilized. © 2014 IEEE.

  7. 40 CFR 258.74 - Allowable mechanisms.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Allowable mechanisms. 258.74 Section... MUNICIPAL SOLID WASTE LANDFILLS Financial Assurance Criteria § 258.74 Allowable mechanisms. The mechanisms... operator establishes a trust fund after having used one or more alternate mechanisms specified in...

  8. 75 FR 4098 - Utility Allowance Adjustments

    Science.gov (United States)

    2010-01-26

    ... URBAN DEVELOPMENT Utility Allowance Adjustments AGENCY: Office of the Chief Information Officer, HUD... are required to advise the Secretary of the need for and request of a new utility allowance for... whether the information will have practical utility; (2) Evaluate the accuracy of the agency's estimate...

  9. 28 CFR 100.11 - Allowable costs.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Allowable costs. 100.11 Section 100.11 Judicial Administration DEPARTMENT OF JUSTICE (CONTINUED) COST RECOVERY REGULATIONS, COMMUNICATIONS ASSISTANCE FOR LAW ENFORCEMENT ACT OF 1994 § 100.11 Allowable costs. (a) Costs that are eligible...

  10. 45 CFR 74.27 - Allowable costs.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 1 2010-10-01 2010-10-01 false Allowable costs. 74.27 Section 74.27 Public..., AND COMMERCIAL ORGANIZATIONS Post-Award Requirements Financial and Program Management § 74.27 Allowable costs. (a) For each kind of recipient, there is a particular set of Federal principles...

  11. 29 CFR 1470.22 - Allowable costs.

    Science.gov (United States)

    2010-07-01

    ... to that circular 48 CFR part 31. Contract Cost Principles and Procedures, or uniform cost accounting... grantee or subgrantee. (b) Applicable cost principles. For each kind of organization, there is a set of Federal principles for determining allowable costs. Allowable costs will be determined in accordance...

  12. 5 CFR 180.104 - Allowable claims.

    Science.gov (United States)

    2010-01-01

    ... mobile homes may be allowed only in cases of collision, theft, or vandalism. (5) Money. Claims for money... claimant's supervisor. (4) Mobile homes. Claims may be allowed for damage to or loss of mobile homes and their contents under the provisions of § 180.104(c)(2). Claims for structural damage to mobile...

  13. 45 CFR 2543.27 - Allowable costs.

    Science.gov (United States)

    2010-10-01

    ... GRANTS AND AGREEMENTS WITH INSTITUTIONS OF HIGHER EDUCATION, HOSPITALS, AND OTHER NON-PROFIT ORGANIZATIONS Post-Award Requirements Financial and Program Management § 2543.27 Allowable costs. For each kind... Organizations.” The allowability of costs incurred by institutions of higher education is determined...

  14. 38 CFR 49.27 - Allowable costs.

    Science.gov (United States)

    2010-07-01

    ... ADMINISTRATIVE REQUIREMENTS FOR GRANTS AND AGREEMENTS WITH INSTITUTIONS OF HIGHER EDUCATION, HOSPITALS, AND OTHER NON-PROFIT ORGANIZATIONS Post-Award Requirements Financial and Program Management § 49.27 Allowable...-Profit Organizations.” The allowability of costs incurred by institutions of higher education...

  15. 20 CFR 435.27 - Allowable costs.

    Science.gov (United States)

    2010-04-01

    ... AGREEMENTS WITH INSTITUTIONS OF HIGHER EDUCATION, HOSPITALS, OTHER NON-PROFIT ORGANIZATIONS, AND COMMERCIAL ORGANIZATIONS Post-Award Requirements Financial and Program Management § 435.27 Allowable costs. For each kind... Organizations.” (c) Allowability of costs incurred by institutions of higher education is determined...

  16. 28 CFR 70.27 - Allowable costs.

    Science.gov (United States)

    2010-07-01

    ... AND AGREEMENTS (INCLUDING SUBAWARDS) WITH INSTITUTIONS OF HIGHER EDUCATION, HOSPITALS AND OTHER NON-PROFIT ORGANIZATIONS Post-Award Requirements Financial and Program Management § 70.27 Allowable costs. (a... Organizations.” The allowability of costs incurred by institutions of higher education is determined...

  17. 15 CFR 14.27 - Allowable costs.

    Science.gov (United States)

    2010-01-01

    ... GRANTS AND AGREEMENTS WITH INSTITUTIONS OF HIGHER EDUCATION, HOSPITALS, OTHER NON-PROFIT, AND COMMERCIAL ORGANIZATIONS Post-Award Requirements Financial and Program Management § 14.27 Allowable costs. For each kind of... Organizations.” The allowability of costs incurred by institutions of higher education is determined...

  18. 44 CFR 13.22 - Allowable costs.

    Science.gov (United States)

    2010-10-01

    ... uniform cost accounting standards that comply with cost principles acceptable to the Federal agency. ... STATE AND LOCAL GOVERNMENTS Post-Award Requirements Financial Administration § 13.22 Allowable costs. (a... increment above allowable costs) to the grantee or subgrantee. (b) Applicable cost principles. For each...

  19. 32 CFR 33.22 - Allowable costs.

    Science.gov (United States)

    2010-07-01

    ... accounting standards that comply with cost principles acceptable to the Federal agency. ... Post-Award Requirements Financial Administration § 33.22 Allowable costs. (a) Limitation on use of... allowable costs) to the grantee or subgrantee. (b) Applicable cost principles. For each kind of...

  20. 36 CFR 1207.22 - Allowable costs.

    Science.gov (United States)

    2010-07-01

    ... uniform cost accounting standards that comply with cost principles acceptable to the Federal agency. ... GOVERNMENTS Post-Award Requirements Financial Administration § 1207.22 Allowable costs. (a) Limitation on use... increment above allowable costs) to the grantee or subgrantee. (b) Applicable cost principles. For each...

  1. 34 CFR 74.27 - Allowable costs.

    Science.gov (United States)

    2010-07-01

    ... Procedures or uniform cost accounting standards that comply with cost principles acceptable to ED. (b) The... OF HIGHER EDUCATION, HOSPITALS, AND OTHER NON-PROFIT ORGANIZATIONS Post-Award Requirements Financial... principles for determining allowable costs. Allowability of costs are determined in accordance with the...

  2. 45 CFR 2541.220 - Allowable costs.

    Science.gov (United States)

    2010-10-01

    ... accounting standards that comply with cost principles acceptable to the Federal agency. ... the grantee or subgrantee. (b) Applicable cost principles. For each kind of organization, there is a set of Federal principles for determining allowable costs. Allowable costs will be determined...

  3. Maximizing the spectral and energy efficiency of ARQ with a fixed outage probability

    KAUST Repository

    Hadjtaieb, Amir

    2015-10-05

    This paper studies the spectral and energy efficiency of automatic repeat request (ARQ) in Nakagami-m block-fading channels. The source encodes each packet into L similar sequences and transmits them to the destination in the L subsequent time slots. The destination combines the L sequences using maximal ratio combining and tries to decode the information. In case of decoding failure, the destination feeds back a negative acknowledgment and then the source sends the same L sequences to the destination. This process continues until successful decoding occurs at the destination with no limit on the number of retransmissions. We consider two optimization problems. In the first problem, we maximize the spectral efficiency of the system with respect to the rate for a fixed power. In the second problem, we maximize the energy efficiency with respect to the transmitted power for a fixed rate. © 2015 IEEE.

  4. Keynes, family allowances and Keynesian economic policy

    OpenAIRE

    Pressman, Steven

    2014-01-01

    This paper provides a short history of family allowances and documents the fact that Keynes supported family allowances as early as the 1920s, continuing through the 1930s and early 1940s. Keynes saw this policy as a way to help households raise their children and also as a way to increase consumption without reducing business investment. The paper goes on to argue that a policy of family allowances is consistent with Keynesian economics. Finally, the paper uses the Luxembourg Income Study to...

  5. Application and improvement of high risk operations control during refueling outage of Qinshan Nuclear Power Plant%秦山核电厂换料大修高风险作业控制应用及优化

    Institute of Scientific and Technical Information of China (English)

    苏松

    2014-01-01

    根据秦山核电厂三十万千瓦机组换料大修高风险作业控制实践经验,介绍一种基于安全许可管理的大修高风险作业控制模式,将高风险作业控制流程嵌入电站生产管理系统,与工单直接关联,实现了高危作业活动识别、风险分析及安全防护措施制定电子流程化。通过对电厂最近六次机组换料大修高风险作业控制相关数据统计、比较,评价高风险作业控制模式在电厂大修中应用效果的稳定性与有效性;根据核电厂大修类作业项目特点,提出机组换料大修期间大纲作业项目高风险作业控制改进方向。%According to the practical experience from Qinshan Nuclear Power Plant,a control mode of high risk op-erations control based on industry safety permission was introduced. The high risk operations control flow was em-bedded in the electronic production management system of Qinshan Nuclear Power Plant,which connected with tasks straightly and realized the electronic workflow of high risk activity recognition,risk analysis and drawing of safety protection measures. By counting and comparing the data of high risk operations control from the recent six times refueling outages of power plant,the stability and effectiveness for application of high risk operations control mode were appraised. According to the characteristics of fixed project during refueling outage of nuclear power plant,the improvement directions of high risk operations control were presented.

  6. 24 CFR 17.43 - Allowable claims.

    Science.gov (United States)

    2010-04-01

    ... by the negligent or wrongful act of the claimant, his agent, the members of his family, or his..., superior authority. (6) Clothing and accessories. Claims may be allowed for damage to, or loss of,...

  7. 45 CFR 34.4 - Allowable claims.

    Science.gov (United States)

    2010-10-01

    .... Damage or loss of personal property, including baggage and household items, while being transported by a carrier, agent or agency of the government, or private conveyance, may be allowed only if the property...

  8. Sign Patterns That Allow the Given Matrix

    Institute of Scientific and Technical Information of China (English)

    邵燕灵; 孙良

    2003-01-01

    Let P be a property referring to a real matrix. For a sign pattern A, if there exists a real matrix B in the qualitative class of A such that B has property P, then we say A allows P. Three cases that A allows an M-matrix, an inverse M-matrix and a P0-matrix are considered. The complete characterizations are obtained.

  9. Regulatory treatment of allowances and compliance costs

    Energy Technology Data Exchange (ETDEWEB)

    Rose, K. [National Regulatory Research Institute, Columbus, OH (United States)

    1993-07-01

    The Clean Air Act Amendments of 1990 (CAAA) established a national emission allowance trading system, a market-based form of environmental regulation designed to reduce and limit sulfur dioxide emissions. However, the allowance trading system is being applied primarily to an economically regulated electric utility industry. The combining of the new form of environmental regulation and economic regulation of electric utilities has raised a number of questions including what the role should be of the federal and state utility regulating commissions and how those actions will affect the decision making process of the utilities and the allowance market. There are several dimensions to the regulatory problems that commissions face. Allowances and utility compliance expenditures have implications for least-cost/IPR (integrated resource planning), prudence review procedures, holding company and multistate utility regulation and ratemaking treatment. The focus of this paper is on the ratemaking treatment. The following topics are covered: ratemaking treatment of allowances and compliance costs; Traditional cost-recovery mechanisms; limitations to the traditional approach; traditional approach and the allowance trading market; market-based cost recovery mechanisms; methods of determining the benchmark; determining the split between ratepayers and the utility; other regulatory approaches; limitations of incentive mechanisms.

  10. 直流输电系统强迫停运探讨%Discussion on forced outages of HVDC transmission system

    Institute of Scientific and Technical Information of China (English)

    朱韬析; 李娟; 王超; 陈为化

    2009-01-01

    There are many protection and monitoring functions in HVDC transmission system. Although the equipments are completely protected, the mal-operation is very difficult to be avoided. In this paper, based on the experiences of Tian-Guang HVDC transmission system, the forced outage and the protection and monitoring which would cause forced outage are introduced first, then the reason caused forced outages in operation in those years and its effect are analyzed. At last, combined with the safety of equipments and the reliability of power system, the improving suggestion to the protection and monitoring function in HVDC transmission system is discussed.%直流输电系统中设置了大量的保护、监视功能,但在确保设备安全的同时,也带来了容易误动的隐患.以天广直流输电系统为例,首先介绍了直流输电系统的强迫停运及可能引起强迫停运的保护监视功能,接着讨论了多年来运行中发生的强迫停运故障原因及故障时对设备的影响,最后综合考虑设备的安全和电网的稳定,对直流输电系统的保护、监视功能提出了改进建议.

  11. Two-way中继系统中基于最小化中断概率的功率分配策略%Optimal power allocation scheme based on minimizing outage probability in Two-way relay system

    Institute of Scientific and Technical Information of China (English)

    刘通; 陈前斌; 唐伦; 张力生

    2011-01-01

    为了降低Two-way中继系统中断概率,提出了一种Two-way中继系统中基于最小化中断概率的功率分配策略.首先推导了Two-way中继系统中断概率的闭合表达式,然后在总功率受限的条件下,提出了一种最小化中断概率的最优功率分配策略(OPA),通过拉格朗日乘数法对该优化模型进行了求解.仿真结果证明了该策略能够有效降低系统的中断概率,提高系统性能.%In order to decrease the outage probability of Two-way relay system, this paper proposed an optimal power allocation scheme based on minimizing outage probability. It first derived the close form of outage probability in Two-way relay system, then proposed an optimal power allocation (OPA) scheme to minimize the outage probability under the condition that total power was limited. Solved the optimal model by Lagrange multiplier method. Simulation result shows that the proposed strategy can decrease the outage probability and enhance the performance of the system.

  12. Space-Time Water-Filling for Composite MIMO Fading Channels

    Directory of Open Access Journals (Sweden)

    2006-01-01

    Full Text Available We analyze the ergodic capacity and channel outage probability for a composite MIMO channel model, which includes both fast fading and shadowing effects. The ergodic capacity and exact channel outage probability with space-time water-filling can be evaluated through numerical integrations, which can be further simplified by using approximated empirical eigenvalue and maximal eigenvalue distribution of MIMO fading channels. We also compare the performance of space-time water-filling with spatial water-filling. For MIMO channels with small shadowing effects, spatial water-filling performs very close to space-time water-filling in terms of ergodic capacity. For MIMO channels with large shadowing effects, however, space-time water-filling achieves significantly higher capacity per antenna than spatial water-filling at low to moderate SNR regimes, but with a much higher channel outage probability. We show that the analytical capacity and outage probability results agree very well with those obtained from Monte Carlo simulations.

  13. 计及缺电成本的用户侧蓄电池储能系统容量规划%Capacity Plan of Battery Energy Storage System in User Side Considering Power Outage Cost

    Institute of Scientific and Technical Information of China (English)

    颜志敏; 王承民; 连鸿波; 衣涛; 时志雄; 张宇

    2012-01-01

    Based on the relevant studies, in order to bring the battery energy storage system economical benefits in the user side caused by reducing capacity of user's distribution station and decreasing the power expenses for user, a value model for reducing loss of the transformer and power outage cost is built. In the mean time, considering the investment cost and operation and maintenance cost, the capacity optimization plan model for user' s battery energy storage system is developed and particle swarm optimization algorithm is used to solve it.%在相关研究的基础上,考虑了用户侧电池储能系统在减少用户配电站建设容量和降低购电费用方面为用户带来的经济价值,建立了其降低配电变压器损耗和停电损失的价值模型。同时,考虑蓄电池储能系统的投资成本和运行维护成本,建立了其容量优化规划模型,并用粒子群优化算法进行了求解。

  14. Quantum theory allows for absolute maximal contextuality

    Science.gov (United States)

    Amaral, Barbara; Cunha, Marcelo Terra; Cabello, Adán

    2015-12-01

    Contextuality is a fundamental feature of quantum theory and a necessary resource for quantum computation and communication. It is therefore important to investigate how large contextuality can be in quantum theory. Linear contextuality witnesses can be expressed as a sum S of n probabilities, and the independence number α and the Tsirelson-like number ϑ of the corresponding exclusivity graph are, respectively, the maximum of S for noncontextual theories and for the theory under consideration. A theory allows for absolute maximal contextuality if it has scenarios in which ϑ /α approaches n . Here we show that quantum theory allows for absolute maximal contextuality despite what is suggested by the examination of the quantum violations of Bell and noncontextuality inequalities considered in the past. Our proof is not constructive and does not single out explicit scenarios. Nevertheless, we identify scenarios in which quantum theory allows for almost-absolute-maximal contextuality.

  15. Power Outage - 16 October

    CERN Multimedia

    2014-01-01

    At 19:03 last night, a fire in an 18kV circuit breaker in building 212 led to a blackout on the Meyrin site. The CERN fire brigade rapidly brought the fire under control and power was restored by 22:25. Many CERN systems were affected and have been brought back in to service overnight, this work will continue through the day.

  16. New software rejuvenation strategy based on measurement and time

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Operational software systems often experience an "aging" phenomenon, characterized by progressive performance degradation and a sudden hang/crash failure. Software rejuvenation is a proactive fault-tolerance strategy aimed to prevent unexpected outages due to aging. A new rejuvenation strategy based on measurement and time, and constructs a SRN model to evaluate this strategy. Numerical results show that this strategy outweighs either the purely measurementbased or the purely time-based strategy and can effectively improve system performance.

  17. Capacity of orthogonal space-time block codes in MISO fading channels with co-channel interference and noise

    Institute of Scientific and Technical Information of China (English)

    YUE DianWu; WANG Qian

    2009-01-01

    Orthogonal space-time block codes (OSTBCs) are an efficient mean In order to exploit the diversity offered by the wireless multiple-input multiple-output (MIMO) channel.This paper considers capacity problems of OSTBCs over spatially correlated multiple-input single-out (MISO) Rayleigh fading channels in the presence of spatially correlated Rayleigh co-channel interference and additive Gaussian noise,and derives exact expressions of the ergodic capacity and outage probability (capacity distribution) for such OSTBCs.Some numerical examples are given to illustrate the effect of co-channel interference on the ergodic and outage capacity of OSTBCs.

  18. 77 FR 34218 - Clothing Allowance; Correction

    Science.gov (United States)

    2012-06-11

    ... construed to impose a restriction that VA did not intend. This document corrects that error. DATES: This... Service, Veterans Benefits Administration, Department of Veterans Affairs, 810 Vermont Avenue NW... medication would be eligible for a clothing allowance for each such appliance or medication if each...

  19. 20 CFR 633.303 - Allowable costs.

    Science.gov (United States)

    2010-04-01

    ... family income does not exceed either 70 percent of the lower living standard income level or the poverty... occupation trained for and at not less than the wage specified in the agreement. (g) Travel costs. (1) The... grantee per quarter. (2) Allowances and loss of wages. Any individual or family member who is a member...

  20. 33 CFR 136.211 - Compensation allowable.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Compensation allowable. 136.211 Section 136.211 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED... PROCEDURES; DESIGNATION OF SOURCE; AND ADVERTISEMENT Procedures for Particular Claims § 136.211...

  1. 33 CFR 136.205 - Compensation allowable.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Compensation allowable. 136.205 Section 136.205 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED... PROCEDURES; DESIGNATION OF SOURCE; AND ADVERTISEMENT Procedures for Particular Claims § 136.205...

  2. 33 CFR 136.241 - Compensation allowable.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Compensation allowable. 136.241 Section 136.241 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED... PROCEDURES; DESIGNATION OF SOURCE; AND ADVERTISEMENT Procedures for Particular Claims § 136.241...

  3. 33 CFR 136.223 - Compensation allowable.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Compensation allowable. 136.223 Section 136.223 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED... PROCEDURES; DESIGNATION OF SOURCE; AND ADVERTISEMENT Procedures for Particular Claims § 136.223...

  4. 33 CFR 136.217 - Compensation allowable.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Compensation allowable. 136.217 Section 136.217 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED... PROCEDURES; DESIGNATION OF SOURCE; AND ADVERTISEMENT Procedures for Particular Claims § 136.217...

  5. 33 CFR 136.235 - Compensation allowable.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Compensation allowable. 136.235 Section 136.235 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED... PROCEDURES; DESIGNATION OF SOURCE; AND ADVERTISEMENT Procedures for Particular Claims § 136.235...

  6. 33 CFR 136.229 - Compensation allowable.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Compensation allowable. 136.229 Section 136.229 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED... PROCEDURES; DESIGNATION OF SOURCE; AND ADVERTISEMENT Procedures for Particular Claims § 136.229...

  7. 43 CFR 12.62 - Allowable costs.

    Science.gov (United States)

    2010-10-01

    ... Public Lands: Interior Office of the Secretary of the Interior ADMINISTRATIVE AND AUDIT REQUIREMENTS AND COST PRINCIPLES FOR ASSISTANCE PROGRAMS Uniform Administrative Requirements for Grants and Cooperative... increment above allowable costs) to the grantee or subgrantee. (b) Applicable cost principles. For each...

  8. 22 CFR 145.27 - Allowable costs.

    Science.gov (United States)

    2010-04-01

    ... Relations DEPARTMENT OF STATE CIVIL RIGHTS GRANTS AND AGREEMENTS WITH INSTITUTIONS OF HIGHER EDUCATION, HOSPITALS, AND OTHER NON-PROFIT ORGANIZATIONS Post-Award Requirements Financial and Program Management § 145...-Profit Organizations.” The allowability of costs incurred by institutions of higher education...

  9. 22 CFR 518.27 - Allowable costs.

    Science.gov (United States)

    2010-04-01

    ... INSTITUTIONS OF HIGHER EDUCATION, HOSPITALS, AND OTHER NON-PROFIT ORGANIZATIONS Post-Award Requirements Financial and Program Management § 518.27 Allowable costs. For each kind of recipient, there is a set of... by institutions of higher education is determined in accordance with the provisions of OMB Circular...

  10. 36 CFR 1210.27 - Allowable costs.

    Science.gov (United States)

    2010-07-01

    ... RULES UNIFORM ADMINISTRATIVE REQUIREMENTS FOR GRANTS AND AGREEMENTS WITH INSTITUTIONS OF HIGHER EDUCATION, HOSPITALS, AND OTHER NON-PROFIT ORGANIZATIONS Post-Award Requirements Financial and Program Management § 1210.27 Allowable costs. For each kind of recipient, there is a set of Federal principles...

  11. 34 CFR 80.22 - Allowable costs.

    Science.gov (United States)

    2010-07-01

    ... CFR part 31. Contract Cost Principles and Procedures, or uniform cost accounting standards that comply... COOPERATIVE AGREEMENTS TO STATE AND LOCAL GOVERNMENTS Post-Award Requirements Financial Administration § 80.22... kind of organization, there is a set of Federal principles for determining allowable costs. For...

  12. 13 CFR 143.22 - Allowable costs.

    Science.gov (United States)

    2010-01-01

    ... to that circular 48 CFR part 31. Contract Cost Principles and Procedures, or uniform cost accounting... Financial Administration § 143.22 Allowable costs. (a) Limitation on use of funds. Grant funds may be used... grantee or subgrantee. (b) Applicable cost principles. For each kind of organization, there is a set...

  13. 38 CFR 43.22 - Allowable costs.

    Science.gov (United States)

    2010-07-01

    ... accounting standards that comply with cost principles acceptable to the Federal agency. ... Requirements Financial Administration § 43.22 Allowable costs. (a) Limitation on use of funds. Grant funds may... the grantee or subgrantee. (b) Applicable cost principles. For each kind of organization, there is...

  14. 22 CFR 135.22 - Allowable costs.

    Science.gov (United States)

    2010-04-01

    ... Procedures, or uniform cost accounting standards that comply with cost principles acceptable to the Federal... AGREEMENTS TO STATE AND LOCAL GOVERNMENTS Post-Award Requirements Financial Administration § 135.22 Allowable... principles. For each kind of organization, there is a set of Federal principles for determining...

  15. 40 CFR 31.22 - Allowable costs.

    Science.gov (United States)

    2010-07-01

    ... accounting standards that comply with cost principles acceptable to the Federal agency. ... Requirements Financial Administration § 31.22 Allowable costs. (a) Limitation on use of funds. Grant funds may... the grantee or sub-grantee. (b) Applicable cost principles. For each kind of organization, there is...

  16. 45 CFR 92.22 - Allowable costs.

    Science.gov (United States)

    2010-10-01

    ... to that circular 48 CFR Part 31. Contract Cost Principles and Procedures, or uniform cost accounting... Financial Administration § 92.22 Allowable costs. (a) Limitation on use of funds. Grant funds may be used... grantee or subgrantee. (b) Applicable cost principles. For each kind of organization, there is a set...

  17. Application of Generators Unplanned Outage Monitoring of Shanxi Power Grid%山西电网机组非计划停运监测应用研究

    Institute of Scientific and Technical Information of China (English)

    徐宏锐

    2015-01-01

    To solve the problem of generators unplanned outage in Shanxi power grid, we developed the monitoring module of harmonious dispatch supporting system by using its on-line monitoring function. By analyzing, we can predict in advance the potential risks and the cause of generators unplanned outage. The application effectively filled the blank of the impact on the security and stability of Shanxi Power Grid, which not only prepared for the power balance in days or a few days ago, but also made a strong technical support for the safe and stable operation of the power grid.%针对山西电网发电机组非停事件,利用和谐调度系统在线监测功能,开发了和谐系统机组非停监测模块,并将其应用到了非停原因分析中.通过分析,可以提前判断机组非停的潜在风险及故障原因.有效填补了机组非停影响电网安全稳定的空白,为日内或日前电网平衡做好充分准备,且为电网安全稳定运行提供有力的技术保障.

  18. On the Required Number of Antennas in a Point-to-Point Large-but-Finite MIMO System: Outage-Limited Scenario

    KAUST Repository

    Makki, Behrooz

    2016-03-22

    This paper investigates the performance of the point-To-point multiple-input-multiple-output (MIMO) systems in the presence of a large but finite numbers of antennas at the transmitters and/or receivers. Considering the cases with and without hybrid automatic repeat request (HARQ) feedback, we determine the minimum numbers of the transmit/receive antennas, which are required to satisfy different outage probability constraints. Our results are obtained for different fading conditions and the effect of the power amplifiers efficiency/feedback error probability on the performance of the MIMO-HARQ systems is analyzed. Then, we use some recent results on the achievable rates of finite block-length codes, to analyze the effect of the codewords lengths on the system performance. Moreover, we derive closed-form expressions for the asymptotic performance of the MIMO-HARQ systems when the number of antennas increases. Our analytical and numerical results show that different outage requirements can be satisfied with relatively few transmit/receive antennas. © 1972-2012 IEEE.

  19. Realization of allowable qeneralized quantum gates

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The most general duality gates were introduced by Long,Liu and Wang and named allowable generalized quantum gates (AGQGs,for short).By definition,an allowable generalized quantum gate has the form of U=YfkjsckUK,where Uk’s are unitary operators on a Hilbert space H and the coefficients ck’s are complex numbers with |Yfijo ck\\ ∧ 1 an d 1ck| <1 for all k=0,1,...,d-1.In this paper,we prove that an AGQG U=YfkZo ck∧k is realizable,i.e.there are two d by d unitary matrices W and V such that ck=W0kVk0 (0

  20. Making It Personal: Per Capita Carbon Allowances

    DEFF Research Database (Denmark)

    Fawcett, Tina; Hvelplund, Frede; Meyer, Niels I

    2009-01-01

    The Chapter highligts the importance of introducing new, efficient schemes for mitigation of global warming. One such scheme is Personal Carbon Allowances (PCA), whereby individuals are allotted a tradable ration of CO2 emission per year.This chapter reviews the fundamentals of PCA and analyzes its...... merits and problems. The United Kingdom and Denmark have been chosen as case studies because the energy situation and the institutional setup are quite different between the two countries....

  1. 76 FR 16629 - Federal Travel Regulation (FTR); Relocation Allowances-Relocation Income Tax Allowance (RITA) Tables

    Science.gov (United States)

    2011-03-24

    ... http://www.gsa.gov/relocationpolicy . Dated: March 21, 2011. Janet Dobbs, Director, Office of Travel... ADMINISTRATION Federal Travel Regulation (FTR); Relocation Allowances-- Relocation Income Tax Allowance (RITA... effective March 24, 2011. FOR FURTHER INFORMATION CONTACT: Mr. Ed Davis, Office of Governmentwide Policy...

  2. Lessons from September 8, 2011 Southwest America Blackout for Prevention and Control of Cascading Outages%美国“9·8”大停电对连锁故障防控技术的启示

    Institute of Scientific and Technical Information of China (English)

    方勇杰

    2012-01-01

    Based on the 2011 Southwest America blackout inquiry report, this paper presents a description of the event evolution and an analysis of technical causes leading to the cascade development from the point of view of prevention and control of cascading outages, including ineffectiveness of security analysis and preventive control, inadequacy of real-time situational awareness, unreasonabilitp of protection relay settings, inappropriateness of control system design and lack of coordination between protection and control. It concludes that several fundamental measures need to be strengthened, including a complete, thorough and timely understanding of system dynamic characteristics, coordination of protection and control actions, and improvement of simulation analysis.%叙述了2011年9月8日在美国西南地区电网发生的大停电事故演化过程,从连锁故障防控的视角分析了事故发展的技术原因,包括安全分析和预防控制技术欠缺、实时状态觉知能力不足、保护定值整定不合理、控制方案设置不当和保护与控制动作不协调。凝练了连锁故障防控技术需要加强的基础性工作,指出必须全面、深入、及时地掌握系统动态特性,协调保护控制动作,提高仿真分析精度。

  3. Optimal power allocation scheme based on minimizing outage probability in two-path relay system%Two-path中继系统中基于最小化中断概率的功率分配方法

    Institute of Scientific and Technical Information of China (English)

    方恒刚; 李莉; 张静; 罗汉文

    2013-01-01

    In order to decrease the outage probability of two-path relay system, this paper derived a closed-form solution of outage probability in DF two-path relay system with the inter-relay interference, and then proposed an optimal power allocation algorithm to minimize the outage probability under the limited total power. The simulation results show that this algorithm can effectively decrease the outage probability and improve the performance of the system.%为了降低two-path中继系统的通信中断概率,针对DF协议中继,推导了two-path中继系统在存在中继间干扰情况下的中断概率闭式解,并在总功率受限的情况下,提出了一种最小化中断概率的最优功率分配算法.仿真验证结果表明该算法能够有效地降低系统的中断概率,提高系统的性能.

  4. 双层异构网络下行中断概率及功率控制研究%Downlink Outage Probability and Power Control in Two-tier Heterogeneous Network

    Institute of Scientific and Technical Information of China (English)

    全震; 滕世海

    2016-01-01

    针对双层异构网络架构复杂、干扰严重的问题,利用空间泊松点过程对Macro-Femto双层网络进行了数学建模,推导了室外MUE和室内FUE的下行中断概率,并提出了基于距离和中断概率的家庭基站覆盖及功率控制优化方案.仿真实验表明,所推导的中断概率表达式是正确的,所提出的方案明显减少了宏用户所受的干扰,降低了宏用户的中断概率,有效提升了整个异构网络的性能.%Aiming at complex architecture and serious interference in two-tier heterogeneous network, the mathematical model of Macro-Femto system is established by using the spatial Poisson point process, and the downlink outage probability of the outdoor Macro users and the indoor Femto users derived, and the optimization scheme of Femtocell coverage and power control based on the distance and outage probability also proposed. Simulation results show that the derived outage probability expression is correct, and the proposed scheme could significantly reduce the interference and outage probability of the macro user, and effectively improves the performance of the whole heterogeneous network.

  5. 配电网可靠性评估中预安排停电的实用数学模型%Mathematical Model of Scheduled Outage in Reliability Assessment of Distribution Network

    Institute of Scientific and Technical Information of China (English)

    王浩浩; 管霖; 吴熳红

    2011-01-01

    目前国内城市配电网的停电事件中预安排停电占据绝对多数,但现有的配电网可靠性理论评估却只考虑了故障停电,缺少对预安排停电影响的评估模型和方法。文中分析了预安排停电的建模特点、导致预安排停电的各类工程、检修项目的不同影响范围。在此基础上,将各类预安排停电项目分为4类停电事件,并分别给出对应的可靠性评估数学模型。模型用于电网规划时,还考虑了新出线网架信息不全给转供判断带来的问题并提出简化处理方法。以珠海市香洲区2010年的项目规划为算例的结果表明,基于项目分类的预安排停电影响的模型具有一定的实用性,适用于配电网可靠性评估。%At present,the scheduled outages account for most of all the outages in the city distribution network,but the existing evaluation methods only take fault outage into account,while neglecting assessment models and methods for scheduled outage.The characteristics of the scheduled outage model and several types of construction/maintenance projects leading to scheduled outage and their impact range are analyzed first.Then,the projects are categorized into four sets based on their impact,with the mathematical model developed for each.The issue of the network structure uncertainty arising from new outlet feeders that brings difficulty to load transfer judgement is also considered in the proposed models.The planning project in Xiangzhou district of Zhuhai city is used as a real example,the results showing that the proposed scheduled outage model is effective in reliability assessment of distribution network.

  6. Outage Performance for Heterogeneous Cellular Networks with Interference Cancellation%基于干扰消除的异构蜂窝网络中断分析

    Institute of Scientific and Technical Information of China (English)

    宋康; 韦磊; 冀保峰; 王雅芳; 黄永明; 杨绿溪

    2016-01-01

    Inheterogeneous cellular networks, small cells provide for the handover of users from the macro cell and organize itself during the transmission. This paper studies the downlink outage performance of heterogeneous cellular networks with an interference cancellation scheme employed at macro base station, which aims to eliminate the cross-tier interference from macro base station to small cell users. Then, the downlink performance of heterogeneous cellular networks is investigated. Expressions of the Probability Density Function (PDF) and Cumulative Distribution Function (CDF) of the received SNRs of both macro and small cell users are derived and closed-form expressions of overall outage probability of the system are provided. Both analytical results and simulations show that the overall performance of the heterogeneous cellular networks is improved with interference cancellation.%在异构网络中,小小区可以为宏基站用户提供接入服务,并能够根据自身条件调节传输参数。该文研究在宏基站端干扰消除技术,来消除宏基站到小小区用户的干扰。该文分析了采用此种方案后异构网络下行链路的整体性能,推导了宏基站和小小区用户接收端信噪比的概率密度函数和分布函数。在此基础上,得到了系统整体中断概率的闭合表达式。理论推导和仿真结果表明,干扰消除方案能够有效提升异构蜂窝网络的整体性能。

  7. Should Experiments With Home Schooling Be Allowed?

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    In July this year, a controversial new school featuring traditional Chinese education, called Meng Mu Tang, came under the spotlight. Unusual in the current primary schooling in China, the private full-time school based in Shanghai differed in both teaching methods and content. "The students, aged between 4 and 12, are taught to recite Confucian classics," said Lu Liwei, one of the school's founders. "No lectures, no simple English

  8. On the Methods for Calculating Annual Allowable Cut

    Directory of Open Access Journals (Sweden)

    V. А. Sokolov

    2014-10-01

    Full Text Available Crisis in supplying regions and the country related to available forest resources and low profitability of forest sector, as a whole, is an indicator of failure of the existing model of forest management and forest use organization in Russia at the present time. Many Russian regions, which are traditionally considered as forest industrial territories, face the challenge of lack of economically accessible forests. The forests are decreasing against a background of under exploitation of the annual allowable cut. This situation occurs in Siberia as well. In many cases, using calculated allowable cut will result in unsustainable harvest levels and a future decrease of accessible forest resources. Thus, the statement that «a volume of wood resource utilization is determined by allowable cut represented the scientifically grounded norm of sustainable forest use» is considered as no more than the declarative proposition. Modeling the normal forest, and using a formula of allowable cut calculation estimated for some decades based on the modeling, is totally unreliable and unreal. The long-term forecast should use analog methods, but it will hardly be sufficiently accurate and adequate to set norms. In order to estimate ecological and economic accessibility of forest resources, an algorithm was made, and a method and model were developed. This model is based on GIS-database and makes it possible to estimate accessibility of forest resources and to map it as well. The conclusion on necessity to determine annual allowable cut in two varieties was drawn following the procedures for calculating annual allowable cut. The first variety is silvicultural (according the currently used methods and the other one is economically accessible allowable cut, which could provide economic effective use of tradable mature wood, taking in to account ecological and economic accessibility of forest resources.

  9. Assessing allowable take of migratory birds

    Science.gov (United States)

    Runge, M.C.; Sauer, J.R.; Avery, M.L.; Blackwell, B.F.; Koneff, M.D.

    2009-01-01

    Legal removal of migratory birds from the wild occurs for several reasons, including subsistence, sport harvest, damage control, and the pet trade. We argue that harvest theory provides the basis for assessing the impact of authorized take, advance a simplified rendering of harvest theory known as potential biological removal as a useful starting point for assessing take, and demonstrate this approach with a case study of depredation control of black vultures (Coragyps atratus) in Virginia, USA. Based on data from the North American Breeding Bird Survey and other sources, we estimated that the black vulture population in Virginia was 91,190 (95% credible interval = 44,520?212,100) in 2006. Using a simple population model and available estimates of life-history parameters, we estimated the intrinsic rate of growth (rmax) to be in the range 7?14%, with 10.6% a plausible point estimate. For a take program to seek an equilibrium population size on the conservative side of the yield curve, the rate of take needs to be less than that which achieves a maximum sustained yield (0.5 x rmax). Based on the point estimate for rmax and using the lower 60% credible interval for population size to account for uncertainty, these conditions would be met if the take of black vultures in Virginia in 2006 was <3,533 birds. Based on regular monitoring data, allowable harvest should be adjusted annually to reflect changes in population size. To initiate discussion about how this assessment framework could be related to the laws and regulations that govern authorization of such take, we suggest that the Migratory Bird Treaty Act requires only that take of native migratory birds be sustainable in the long-term, that is, sustained harvest rate should be

  10. 基于键盘扫描算法的多路断电报警系统设计%Design of multi-channel outage warning system based on keyboard scanning algorithm

    Institute of Scientific and Technical Information of China (English)

    曾培彬; 黄丹坤

    2012-01-01

    A multi-channel outage warning system was designed based on the keyboard scanning algorithm. The power-off signal is sent to AT89C51 MCU by related interface circuit, and then sent to the monitoring software of PC after detection by the improved keyboard scanning algorithm to perform the remote monitoring of the power supply in the unattended equipment room. The system is concise y can detect multiple power supplies at the same time and generate the results from the analysis of PC software. Due to its high timeliness and accuracy, the system has been put into service in the omnirange radio beacon room of Shantou Air Traffic Management Station of Civil Aviation of China.%在此提出基于键盘扫描算法的多路断电预警系统的设计,通过设计相关的接口电路将断电信号接入AT89C51单片机,经过改进型键盘扫描算法检测后送往PC机监控软件,实现对机房电源的无人远程监控.该系统设计简洁,能对多路电源同时检测,并在PC机软件上进行分析得出结论,预警时效性高,准确性高,目前已在民航汕头空管站信标台机房投入使用.

  11. Reaching Consensus by Allowing Moments of Indecision

    Science.gov (United States)

    Svenkeson, A.; Swami, A.

    2015-10-01

    Group decision-making processes often turn into a drawn out and costly battle between two opposing subgroups. Using analytical arguments based on a master equation description of the opinion dynamics occurring in a three-state model of cooperatively interacting units, we show how the capability of a social group to reach consensus can be enhanced when there is an intermediate state for indecisive individuals to pass through. The time spent in the intermediate state must be relatively short compared to that of the two polar states in order to create the beneficial effect. Furthermore, the cooperation between individuals must not be too low, as the benefit to consensus is possible only when the cooperation level exceeds a specific threshold. We also discuss how zealots, agents that remain in one state forever, can affect the consensus among the rest of the population by counteracting the benefit of the intermediate state or making it virtually impossible for an opposition to form.

  12. Finding All Allowed Edges in a Bipartite Graph

    CERN Document Server

    Tassa, Tamir

    2011-01-01

    We consider the problem of finding all allowed edges in a bipartite graph $G=(V,E)$, i.e., all edges that are included in some maximum matching. We show that given any maximum matching in the graph, it is possible to perform this computation in linear time $O(n+m)$ (where $n=|V|$ and $m=|E|$). Hence, the time complexity of finding all allowed edges reduces to that of finding a single maximum matching, which is $O(n^{1/2}m)$ [Hopcroft and Karp 1973], or $O((n/\\log n)^{1/2}m)$ for dense graphs with $m=\\Theta(n^2)$ [Alt et al. 1991]. This time complexity improves upon that of the best known algorithms for the problem, which is $O(nm)$ ([Costa 1994] for bipartite graphs, and [Carvalho and Cheriyan 2005] for general graphs). Other algorithms for solving that problem are randomized algorithms due to [Rabin and Vazirani 1989] and [Cheriyan 1997], the runtime of which is $\\tilde{O}(n^{2.376})$. Our algorithm, apart from being deterministic, improves upon that time complexity for bipartite graphs when $m=O(n^r)$ and $...

  13. Analysis of Standard Time Management of Power Outage Maintenance%浅析规范停电检修时间管理

    Institute of Scientific and Technical Information of China (English)

    吴伟洁; 杨佳

    2011-01-01

    为规范停电检修时间管理,应提前作好衔接工作,并提前为下一环节提供必要的信息,对输变电设备检修的工作时限标准化提出要求并纳入ERP考核,达到有效控制各环节可能发生的无效时间,提高输变电设备供电可靠性.

  14. Real-time Implementation of Vision, Inertial, and GPS Sensors to Navigate in an Urban Environment

    Science.gov (United States)

    2015-03-01

    errors from a GPS outage , and provide a better navigation solution than which would be available if the system operated on GPS and IMU solutions...t is the change in time. The discretized noise power matrix Qd(tk) will be determined by using the Van Loan method [22]. The three step Van Loan...be rotated into the navigation frame defined at the time of the final image. The reason for not rotating the translation into the navigation frame at

  15. 40 CFR 73.21 - Phase II repowering allowances.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 16 2010-07-01 2010-07-01 false Phase II repowering allowances. 73.21... (CONTINUED) SULFUR DIOXIDE ALLOWANCE SYSTEM Allowance Allocations § 73.21 Phase II repowering allowances. (a) Repowering allowances. In addition to allowances allocated under § 73.10(b), the Administrator will...

  16. 一种配电网线路不停电融冰方法%A Non-outage De-icing Method of Distribution Lines

    Institute of Scientific and Technical Information of China (English)

    杨少杰; 高一波

    2016-01-01

    A non-outage de-icing method of distribution lines is proposed. By lowering operating voltage of the iced distribution lines and increasing the current of the iced lines, the ice is melted by heat. A pair of wide-range on-load tap changer transformers are connected in series with both terminals of the iced lines through switches. By adjustment of the two transformers, the operating voltage of the iced lines is lowered to ensure voltage stability at the load terminal. A simulation model of non-outage deicing system of distribution lines is established based on PSCAD platform to simulate and analyze line deicing under different operating condi-tions; besides, the various reactive power compensation schemes are compared to provide voltage support for lines. In the end, the application scenario of the scheme is expounded.%提出了一种配网线路不停电融冰的方法,通过降低配电网线路覆冰段的运行电压、增加覆冰段线路电流,以实现热力融冰。将2台大范围有载调压变压器通过开关装置串联接入线路覆冰段两端,通过这2台融冰变压器的协同调节降低线路覆冰段运行电压,并保证负荷端电压的稳定。基于PSCAD平台搭建了配电网线路不停电融冰系统仿真模型,对不同工况下的线路融冰运行情况进行了仿真分析,并对不同无功补偿方案进行对比分析,从而为线路提供电压支撑,最后给出了该方案的适用场合。

  17. 电网停电综合管理与分析决策系统的研究与开发%Study and development of outage comprehensive management and analysis decision system for power grids

    Institute of Scientific and Technical Information of China (English)

    郇嘉嘉; 王钢; 李海锋; 汪隆君; 李平

    2012-01-01

    针对电力企业在停电管理中存在的不足与业务需求,提出了电网停电综合管理与分析决策系统物理构架、逻辑构架与功能的设计思路.基于电网最优综合停电模型的理论体系,采用Java企业应用平台对系统进行了开发.该系统从电网运行方式、负荷水平、运维资源配置等实际情况出发,以电网经济性与可靠性综合效益最优为目标,通过对停电计划的定量分析、评价和比较,自动生成最优决策方案,并具有停电计划关联自动提醒、工作量均衡分析、停电计划辅助更新以及停电设备分析评估等功能.该系统的试点运行效果充分表明其不仅能够为停电计划编制提供强有力的技术支持,还为提高各部门协同运作效率、提升客户服务层次奠定了坚实的业务基础,具有极大的理论研究意义和工程应用价值.%According to the deficiencies and business requirements in outage management process of power enterprises, this paper proposes the design ideas of the physical structure, logic structure and function modules for the outage comprehensive management and analysis decision system. Based on the theoretical system of comprehensive optimal outage model, this paper adopts the technology of Java Platform Enterprise Edition to develop the system. Considering the actual conditions of the power grids operation, load level, resource allocation and so on, the system takes comprehensive benefits of power grids economy and reliability as the optimizing objective. By quantitative analysis, evaluation and comparison of outage schedules, it makes the optimal outage scheduling automatically with the functions of automated association and reminder for outage schedules, equilibrium analysis for workload, assistant update, analysis and evaluation for outage equipments and so on. The operation effect of the system in pilot areas fully proves that it can not only provide strong technical support to plan

  18. 200 MW Thermal Power Plant Unit Film-forming Amines Outage Protection Method Application%200MW机组成膜胺停炉保护方法应用

    Institute of Scientific and Technical Information of China (English)

    李朝燕

    2013-01-01

    介绍几种常用停炉保护方法,结合实例从实验室试验、现场实施、汽水品质监控三方面分析成膜胺停炉保护方法的应用情况,说明应用效果,并提出应用中的注意事项。%This paper introduces several common outage pro-tection methods ,analyzes the application condition of film-forming amines outage protection method through the laboratory experiment ,field implementation ,water and steam quality mo-nitoring ,and illustrates the application effect ,and puts forward attentions should be mentioned during application .

  19. Allowed and forbidden transitions in artificial hydrogen and helium atoms.

    Science.gov (United States)

    Fujisawa, Toshimasa; Austing, David Guy; Tokura, Yasuhiro; Hirayama, Yoshiro; Tarucha, Seigo

    2002-09-19

    The strength of radiative transitions in atoms is governed by selection rules that depend on the occupation of atomic orbitals with electrons. Experiments have shown similar electron occupation of the quantized energy levels in semiconductor quantum dots--often described as artificial atoms. But unlike real atoms, the confinement potential of quantum dots is anisotropic, and the electrons can easily couple with phonons of the material. Here we report electrical pump-and-probe experiments that probe the allowed and 'forbidden' transitions between energy levels under phonon emission in quantum dots with one or two electrons (artificial hydrogen and helium atoms). The forbidden transitions are in fact allowed by higher-order processes where electrons flip their spin. We find that the relaxation time is about 200 micro s for forbidden transitions, 4 to 5 orders of magnitude longer than for allowed transitions. This indicates that the spin degree of freedom is well separated from the orbital degree of freedom, and that the total spin in the quantum dots is an excellent quantum number. This is an encouraging result for potential applications of quantum dots as basic entities for spin-based quantum information storage.

  20. 考虑线路多种停运模式的静态电压稳定风险评估%Risk Assessment of Static Voltage Stability by Considering Multiple Outage Model of Lines

    Institute of Scientific and Technical Information of China (English)

    吴昊; 薛贵挺; 张焰; 杨增辉; 冯煜尧

    2011-01-01

    Due to the common mode outages and dependent outages have great impact on system static voltage stability,this paper focuses on the establishment of the equivalent branch outage model for two parallel transmission lines by considering outage overlapping, then computes the state probability of transmission system. Basing on the state probability model of power system, a risk index system of static voltage stability and the calculation method of every index are presented. By the voltage stability criteria based on CPF and optimal load shedding model, the loss of voltage stability of transmission system can be judged and controlled. Taking an area of power grid for east china for example, the risk of static voltage stability is assessed, which verifies the effectiveness of the proposed method.%鉴于双回平行输电线路共同模式停运和相关停运对系统电压稳定性影响较大,本文重点建立了双回线多种停运模式重叠的支路等效停运模型,进而计算输电系统状态概率.在输电系统状态概率模型的基础上,提出输电系统静态电压稳定风险评估指标体系及各项指标计算方法,其中通过基于连续潮流的电压稳定性判据及最优切负荷模型,对输电系统电压失稳进行判定及校正控制.最后以华东某地区电网为例进行静态电压稳定风险评估,说明本文所提方法的有效性.

  1. Nakagami-m信道下DAF选择中继的中断性能分析%Outage Performance of Selection Decode-and-Forward Relay Network over Nakagami-m Fading Channels

    Institute of Scientific and Technical Information of China (English)

    啜钢; 刘振兴; 王涛

    2011-01-01

    To solve the complicated problem of analysis of outage performance in cooperative communication system, a theoretical analysis method is proposed. A selection relay model with a direct link over independent identically distributed Nakagami-m fading channels is considered based on the power restricted cooperative communication system. An analytical expression of outage probability is derived and the outage performance is analyzed for this model. The optimal power allocation is also investigated and a power allocation factor in a specific relay number is given. Simulations show that the outage performance is evidently improved compared with other selection relay models. The optimal power allocation ia also investigated and a power allocation factor in a specific relay number is given.%为了解决协作通信系统中选择中继算法中断性能分析复杂的问题,提出了一种新的中断分析方法.基于功率受限协作通信系统,考虑Nakagami-m独立同分布信道下一种带有直通链路的选择中继模型,在该模型下推导了中断概率表达式,分析了系统的中断性能,经仿真验证了理论分析的准确性.探讨了优化功率分配,给出特定中继数情况下的功率分配系数.分析结果表明,在该模型下的中断性能与已有模型相比均有所提高.

  2. 基于模糊推理的配电网停电原因分析系统%Distribution Network Outage Cause Analyzing System Based on Fuzzy Inference

    Institute of Scientific and Technical Information of China (English)

    周志宇; 周静; 江东林; 艾欣

    2013-01-01

    针对配电网停电原因复杂、停电研判决策不易等问题,对停电原因进行了深入分析并开发了应用系统.基于停电后其他相关系统可提供的信息及电网自身特点,提出了分层求解方法,并采用模糊外展理论进行了停电原因分析,采用混合架构完成了系统设计与开发,并在生产指挥平台上完成了系统部署.通过在配电网生产抢修指挥中的应用,证明了该系统的有效性和实用性.%To tackle the outage cause identification problem and the difficulty in decision-making for power outage judgment of the distribution system,a distribution network outage cause analyzing system is proposed based on fuzzy inference,and its application system is developed.By drawing on the information provided by related systems and the characteristics of the distribution system itself,a hierarchical solving method and the fuzzy abduction theory are used to analyze the outage causes.The system is completed by using the hybrid architecture and the production is deployed on the production command platform.Application in the command of production and emergency repair shows the system proposed is effective and practical.

  3. DF协作系统中基于中断概率的功率分配算法%Power allocation algorithm based on outage probability for DF cooperative systems

    Institute of Scientific and Technical Information of China (English)

    宋婧; 葛建华; 李靖

    2011-01-01

    Since the equal power allocation (EPA) between the source node and the relay node in the decodeforward (DF) cooperative communication system results in resource inefficiency, a power allocation algorithm based on outage probability analysis is proposed. This algorithm aims to reduce the average outage probability of the system, in which the upper and lower bound expressions for the system average outage probability of the model are derived according to the average signal to noise ratios of the upper link channels of and the channels between users. The power allocation factor that leads to a lower system average outage probability is obtained by the golden section method. Simulation results show that, all conditions being the same, this power allocation scheme can achieve a better performance than the equal power allocation (EPA) scheme.%针对译码转发(DF)协作通信系统中源和中继采用平均功率分配,导致系统资源利用率较低的问题,提出了一种基于中断概率分析的功率分配算法.该算法以降低系统的中断概率为目标,根据用户上行信道和用户间信道的平均信噪比,推导出该模型的系统平均中断概率上下限表达式,并通过黄金分割法迭代出使系统平均中断概率降低的功率分配因子.仿真结果表明,在相同条件下,该功率分配方案比平均功率分配(EPA)方案性能更优.

  4. 中核运行二厂大修辐射防护管理经验%The Radiation Protection Management Experience for Refueling Outage of NPP 2, CNNC Nuclear Power Operations Management Limited Company

    Institute of Scientific and Technical Information of China (English)

    倪伟; 陈高飞; 刘杰; 稂其良

    2013-01-01

    Since commercial operation in 2002, the NPP 2 of CNNO has been safe in operation for twelve years,and finished RP control successfuly in the 22 refueling outages. During the twelve years'operation, the RP management system was established and developed constantly, it also made good achievements in RP supervision and management. The author summarized the relevant RP management experience of refueling outages of CNNO Qinshan NPP 2, introduced the RP control actions for each stage of refueling outage, and discussed the key points and difficulty of RP control in refueling outage.%中核核电运行管理有限公司二厂(简称中核运行二厂)自2002年商业运行以来,已安全运行12个年头,顺利完成了22次换料大修的辐射安全控制,在12年的生产实践中,建立并不断完善了大修辐射管理体系,在历次大修中较好的发挥了辐射安全监督与管理的职能。本文总结了中核运行二厂大修辐射防护管理经验,系统地介绍了大修各阶段辐射防护控制所采取的行动,并对大修辐射防护管理的重点及难点进行探讨。

  5. 中继选择协议下的认知无线电系统性能研究%Research the outage performance of cognitive radio system based on protocols of relay selection

    Institute of Scientific and Technical Information of China (English)

    唐菁敏; 龙华; 邵玉斌; 彭艺

    2012-01-01

    An approximate outage probability formulation were derived for amplify-and-forward with relay selection (SAF), decode-and-forward with relay selection (SDF) protocol and hybrid protocol with relay selection (HPRS) on the premise of guarantee primary user quality of service (QoS) and limit of maximal power in cognitive user. By Monte Carlo simulation, the rationality of the approximate outage probability formulation is validated. Theoretical analysis and simulation results show that the outage probability of three cooperative protocols is closely related to interference limit and maximal power in cognitive user. Meanwhile, the three protocols can achieve the full space diversity and the HPRS outperforms both the SAF and SDF in outage performance.%在保证授权用户服务质量(QoS)和认知用户峰值功率限制的前提下,推导出高信噪比时放大转发中继选择(SAF)协议、解码转发中继选择(SDF)协议和混合中继选择协议(HPRS)下认知中继系统中断概率的近似表达式.Monte Carlo仿真验证了三种协议下中断概率近似表达式的合理性,理论和仿真结果表明,三种协议的中断概率与干扰限制条件和认知用户峰值功率密切相关,且HPRS中断性能要优于SAF和SDF.

  6. Minimization of outage probability of WiMAX link supported by laser link between a high-altitude platform and a satellite.

    Science.gov (United States)

    Arnon, Shlomi

    2009-07-01

    Various technologies for the implementation of a WiMAX (IEEE802.16) base station on board a high-altitude platform (HAP) are currently being researched. The network configuration under consideration includes a satellite, several HAPs, and subscribers on the ground. The WiMAX base station is positioned on the satellite and connects with the HAP via an analog RF over-laser communication (LC) link. The HAPs house a transparent transponder that converts the optic signal to a WiMAX RF signal and the reverse. The LC system consists of a laser transmitter and an optical receiver that need to be strictly aligned to achieve a line-of-sight link. However, mechanical vibration and electronic noise in the control system challenge the transmitter-receiver alignment and cause pointing errors. The outcome of pointing errors is fading of the received signal, which leads to impaired link performance. In this paper, we derive the value of laser transmitter gain that can minimize the outage probability of the WiMAX link. The results indicate that the optimum value of the laser transmitter gain is not a function of the pointing error statistics.

  7. Security Evaluation and Auxiliary Decision-making Method for Integrated Generation and Transmission Outage Schedule%发输电一体化检修计划安全评估与辅助决策方法

    Institute of Scientific and Technical Information of China (English)

    谢丽荣; 杨争林; 张淳; 环加飞

    2012-01-01

    In light of the current status of outage schedule based mostly on experience, security evaluation and optimization method of outage schedule based on bus load supply adequacy (LSA) and equivalent generation capacity loss (EGCL) is proposed with practical engineering computation method studied in detail. Besides, quantization security evaluation and optimization of outage schedule is implemented. By the results of sensitivity analysis based on the net model topology, the load supply adequacy (LSA) and equivalent generation capacity loss (EGCL) are calculated. This method is instructive for the outage schedule and has been applied in integrative optimization and management of outage schedule. The feasibility of this method is proved by engineering application.%检修计划编制过程中需要对设定检修方式下的系统运行状态进行安全评估,而目前检修计划编制缺乏必要的安全分析手段,过度依赖经验,难以适应大电网运行控制需要。提出基于母线负荷供应充裕度和等效发电容量损失指标的检修计划评估与安全辅助方法。利用网络拓扑灵敏度分析技术计算满足静态安全约束的母线负荷供应充裕度和等效发电容量损失,并根据该指标评估检修计划的安全性。该方法已在某区域电网检修计划优化管理系统中得到应用,结果表明该方法能够为计划编制人员提供指导性意见。

  8. Statistical methods of economic and reliability benefits in outage management%停电管理的经济效益与可靠性效益统计方法

    Institute of Scientific and Technical Information of China (English)

    杜力; 黎灿兵; 熊浩清; 杜亮; 程子霞; 曹丽华

    2011-01-01

    科学的停电管理可以取得较好的经济效益和可靠性效益.分析了停电管理效益的宏观统计方法,分别用增供电量和停电时户数描述经济效益和可靠性效益.研究了停电管理中实现增供扩销的措施,从微观角度分析增供扩销效果的统计方法.最后提出停电管理中评估经济效益与可靠性效益的指标,为管理层提供停电管理决策支持,同时更加准确地进行业绩考核,提高供电企业的精细化管理水平,实现供需双赢.实践证明,所提出的方法具有较强的实用性.%Scientific outage management can achieve great economic benefits and reliability benefits. The macro-statistic method of outage management benefit is analyzed. The economic and reliability benefits are described by increased electricity sales and number of outage hour-households respectively. The measures that can realize supply increase and marketing enlarging are studied and the practical effect of these statistical methods are analyzed from microcosmic angle. Finally, the indicators of economic benefits and reliability benefits in outage management are put forward. These indicators can provide outage management decision support for management layer, and also achieve more accurate performance assessment, which can improve the fine management level of power supply enterprise, and also achieve benefit for both supply enterprise and energy consumer. It is proved that the methods proposed are practical.This work is supported by the National High Technology Research and Development Program of China (863 Program) (No. SQ2010AA0500165004).

  9. Outage analysis for parallel relay free-space optical communication in strong turbulence%强湍流下并行中继自由空间光通信的中断分析

    Institute of Scientific and Technical Information of China (English)

    王俊波; 盛明; 谢秀秀; 焦媛

    2012-01-01

    在大气强湍流条件下,对并行中继自由空间光通信系统的中断概率进行了研究.考虑大气衰减、大气湍流和指向误差对自由空间光通信系统传输性能的影响,建立了自由空间光通信系统的复合信道模型.基于此信道模型,推导了并行中继自由空间光通信系统端到端中断概率的解析表达式.最后,通过计算机仿真分析了发送功率、指向误差及通信距离对通信系统中断概率的影响.仿真结果表明,并行中继传输技术可以有效提高自由空间光通信系统的中断性能.此外,所推导中断概率的解析表达式可准确地评估并行中继自由空间光通信系统的传输性能,为未来自由空间光通信系统的设计提供理论依据.%This paper studies the outage probability for parallel relay Free-space Optical(FSO) communication systems under a condition of strong turbulence. By considering the influences of atmospheric attenuation, atmospheric turbulence and pointing errors on the transmission performance of FSO communication systems, this paper establishes a composite channel model. Based on the model, an analytical expression is further derived for the end-to-end outage probability of parallel relay FSO communication systems. Finally, the effects of transmitted powers, pointing errors and communication distances on outage probability are analyzed through computer simulation. Simulation results show that parallel relay transmission is a promising technology to increase the outage performance and the de-rived analytical expression can provide sufficient precision for evaluating the outage performance of parallel relay free-space optical communication systems, which is helpful to the design of future free space optical communication systems.

  10. 基于“站-线-变-户”电网模型的预约停电管理模型设计%Appointment power outage management business model design based on “Station - line - change - households” grid model

    Institute of Scientific and Technical Information of China (English)

    于涛

    2014-01-01

    Based oninformation integration camp with "Station - line - change - households" grid model, appointment blackout that allow customers to participate in the development of power cut scheme will be performed in the power supply enterprise customer information and interaction platform.Establish an appointment outage management model, namely screening appointment blackout customers,select the best service channels to communicate with customers,pooled analysis of customer feedback across channels,and develop optimal algorithm to formulate an optimal power cut scheme.%本文基于营配信息集成“站-线-变-户”电网模型,让客户参与停电计划的制定,在供电企业客服信息与互动平台实行预约停电。建立预约停电管理模型,即筛选预约停电客户群,选择最佳服务渠道与客户进行沟通,汇集分析各渠道客户的意见,通过算法处理制定最优的停电计划。

  11. 7 CFR 3560.202 - Establishing rents and utility allowances.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 15 2010-01-01 2010-01-01 false Establishing rents and utility allowances. 3560.202... Establishing rents and utility allowances. (a) General. Rents and utility allowances for rental units in Agency... Agency. (b) Agency approval. All rents and utility allowances set by borrowers are subject to...

  12. Bonneville, Power Administration Timing System

    Science.gov (United States)

    Martin, Kenneth E.

    1996-01-01

    Time is an integral part of the Bonneville Power Administration's (BPA) operational systems. Generation and power transfers are planned in advance. Utilities coordinate with each other by making these adjustments on a timed schedule. Price varies with demand, so billing is based on time. Outages for maintenance are scheduled to assure they do not interrupt reliable power delivery. Disturbance records are aligned with recorded timetags for analysis and comparison with related information. Advanced applications like traveling wave fault location and real-time phase measurement require continuous timing with high precision. Most of BPA is served by a Central Time System (CTS) at the Dittmer Control Center near Portland, OR. This system keeps time locally and supplies time to both the control center systems and field locations via a microwave signal. It is kept synchronized to national standard time and coordinated with interconnected utilities. It is the official BPA time. Powwer system control and operation is described, followed by a description of BPA timing systems including CTS, the Fault Location Acquisition Reporter, time dissemination, and phasor measurements. References are provided for further reading.

  13. Exponentially Distributed Outages of Decreased ACTH and Cortisol Responses to Stress in Healthy Adults with Childhood Maltreatment

    Directory of Open Access Journals (Sweden)

    Geetha. T

    2014-11-01

    Full Text Available Preclinical research findings suggest that exposure to stress and concomitantly hypothalamus-pituitary-adrenal (HPA axis activation during early development can have permanent and potentially deleterious effects. A history of early-life abuse or neglect appears to increase risk for mood and anxiety disorders. Abnormal HPA response to stress challenge has been reported in adult patients with Major Depressive Disorder and PostTraumatic Stress Disorder. This paper discussed the constant stress level of adult patients with times to damage of stress effect and recoveries. Also In adults without diagnosable psychopathology, childhood maltreatment is associated with diminished HPA axis response to a psychosocial stressor.

  14. 具有天线选择的认知MISO系统中断性能分析%Outage performance of MISO-CR with antenna selection

    Institute of Scientific and Technical Information of China (English)

    李静

    2014-01-01

    针对认知 MISO 系统,分析了三种天线选择方案下次用户的中断性能。与已有文献不同,不仅考虑了次用户对主用户的干扰功率约束,还考虑了次用户发送峰值功率约束和主用户对次用户的干扰。进一步基于不同的天线选择方案,从理论上推导出次用户中断概率的闭合表达式,并通过Monte-Carlo 仿真验证理论推导的正确性。仿真结果表明,在瑞利平衰落信道环境中,次用户采用天线选择方案能有效降低次用户的中断概率,避免次用户频繁切换信道。%To improve the performance of multi-input single-output cognitive radio ( MISO-CR ) networks with spectrum sharing model , we propose three transmit antenna selection schemes of minimum interference selection , maximum data power and maximum the received SINR . The cognitive user has to consider not only the interference caused by primary user , as long as the interference temperature constraint at primary user , but the transmit peak power can be limited . In this paper , close-form expressions of the outage are derived under the downlink flat-fading Rayleigh channel conditions .

  15. Climate Throughout Geologic Time Was Cooled by Sequences of Explosive Volcanic Eruptions Forming Aerosols That Reflect and Scatter Ultraviolet Solar Radiation and Warmed by Relatively Continuous Extrusion of Basaltic Lava that Depletes Ozone, Allowing More Solar Ultraviolet Radiation to Reach Earth

    Science.gov (United States)

    Ward, P. L.

    2015-12-01

    Active volcanoes of all sizes and eruptive styles, emit chlorine and bromine gases observed to deplete ozone. Effusive, basaltic volcanic eruptions, typical in Hawaii and Iceland, extrude large lava flows, depleting ozone and causing global warming. Major explosive volcanoes also deplete ozone with the same emissions, causing winter warming, but in addition eject megatons of water and sulfur dioxide into the lower stratosphere where they form sulfuric-acid aerosols whose particles grow large enough to reflect and scatter ultraviolet sunlight, causing net global cooling for a few years. The relative amounts of explosive and effusive volcanism are determined by the configuration of tectonic plates moving around Earth's surface. Detailed studies of climate change throughout geologic history, and since 1965, are not well explained by greenhouse-gas theory, but are explained quite clearly at OzoneDepletionTheory.info. Ozone concentrations vary substantially by the minute and show close relationships to weather system highs and lows (as pointed out by Dobson in the 1920s), to the height of the tropopause, and to the strength and location of polar vortices and jet streams. Integrating the effects of volcanism on ozone concentrations and the effects of ozone concentrations on synoptic weather patterns should improve weather forecasting. For example, the volcano Bárðarbunga, in central Iceland, extruded 85 km2 of basaltic lava between August 29, 2014, and February 28, 2015, having a profound effect on weather. Most surprising, more than a week before the March 4 eruption of Eyjafjallajökull in 2010, substantial amounts of ozone were released in the vicinity of the volcano precisely when surface deformation showed that magma first began moving up from sills below 4 km depth. Ozone similarly appears to have been emitted 3.5 months before the Pinatubo eruption in 1991. Readily available daily maps of ozone concentrations may allow early warning of an imminent volcanic

  16. The STAR trial protocol: a randomised multi-stage phase II/III study of Sunitinib comparing temporary cessation with allowing continuation, at the time of maximal radiological response, in the first-line treatment of locally advanced/metastatic Renal Cancer

    Directory of Open Access Journals (Sweden)

    Collinson Fiona J

    2012-12-01

    Full Text Available Abstract Background Over recent years a number of novel therapies have shown promise in advanced renal cell carcinoma (RCC. Internationally the standard of care of first-line therapy is sunitinib™, after a clear survival benefit was demonstrated over interferon-α. Convention dictates that sunitinib is continued until evidence of disease progression, assuming tolerability, although there is no evidence that this approach is superior to intermittent periods of treatment. The purpose of the STAR trial is to compare the standard treatment strategy (conventional continuation strategy, CCS with a novel drug free interval strategy (DFIS which includes planned treatment breaks. Methods/Design The STAR trial is an NIHR HTA-funded UK pragmatic randomised phase II/III clinical trial in the first-line treatment of advanced RCC. Participants will be randomised (1:1 to either a sunitinib CCS or a DFIS. The overall aim of the trial is to determine whether a DFIS is non-inferior, in terms of 2-year overall survival (OS and quality adjusted life years (QALY (averaged over treatment and follow up, compared to a CCS. The QALY primary endpoint was selected to assess whether any detriment in terms of OS could be balanced with improvements in quality of life (QoL. This is a complex trial with a number of design challenges, and to address these issues a feasibility stage is incorporated into the trial design. Predetermined recruitment (stage A and efficacy (stage B intermediary endpoints must be met to allow continuation to the overall phase III trial (stage C. An integral qualitative patient preference and understanding study will occur alongside the feasibility stage to investigate patients’ feelings regarding participation or non-participation in the trial. Discussion The optimal duration of continuing sunitinib in advanced RCC is unknown. Novel targeted therapies do not always have the same constraints to treatment duration as standard chemotherapeutic agents

  17. 27 CFR 20.24 - Allowance of claims.

    Science.gov (United States)

    2010-04-01

    ... OF THE TREASURY LIQUORS DISTRIBUTION AND USE OF DENATURED ALCOHOL AND RUM Administrative Provisions Authorities § 20.24 Allowance of claims. The appropriate TTB officer is authorized to allow claims for...

  18. 27 CFR 22.23 - Allowance of claims.

    Science.gov (United States)

    2010-04-01

    ... OF THE TREASURY LIQUORS DISTRIBUTION AND USE OF TAX-FREE ALCOHOL Administrative Provisions Authorities § 22.23 Allowance of claims. The appropriate TTB officer is authorized to allow claims for...

  19. 32 CFR 842.35 - Depreciation and maximum allowances.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 6 2010-07-01 2010-07-01 false Depreciation and maximum allowances. 842.35... LITIGATION ADMINISTRATIVE CLAIMS Personnel Claims (31 U.S.C. 3701, 3721) § 842.35 Depreciation and maximum allowances. The military services have jointly established the “Allowance List-Depreciation Guide”...

  20. 42 CFR 50.504 - Allowable cost of drugs.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Allowable cost of drugs. 50.504 Section 50.504... APPLICABILITY Maximum Allowable Cost for Drugs § 50.504 Allowable cost of drugs. (a) The maximum amount which may be expended from program funds for the acquisition of any drug shall be the lowest of (1)...

  1. 45 CFR 1801.43 - Allowance for books.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 4 2010-10-01 2010-10-01 false Allowance for books. 1801.43 Section 1801.43... HARRY S. TRUMAN SCHOLARSHIP PROGRAM Payments to Finalists and Scholars § 1801.43 Allowance for books. The cost allowance for a Scholar's books is $1000 per year, or such higher amount published on...

  2. 24 CFR 891.785 - Adjustment of utility allowances.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Adjustment of utility allowances... Handicapped Families and Individuals-Section 162 Assistance § 891.785 Adjustment of utility allowances. In... adjustment of utility allowances provided in § 891.440 apply....

  3. 24 CFR 891.440 - Adjustment of utility allowances.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Adjustment of utility allowances... Project Management § 891.440 Adjustment of utility allowances. This section shall apply to projects funded... submit an analysis of any utility allowances applicable. Such data as changes in utility rates and...

  4. 24 CFR 886.326 - Adjustment of utility allowances.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Adjustment of utility allowances... utility allowances. When the owner requests HUD approval of an adjustment in Contract Rents under § 886.312, an analysis of the project's Utility Allowances must be included. Such data as changes in...

  5. 24 CFR 880.610 - Adjustment of utility allowances.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Adjustment of utility allowances... Management § 880.610 Adjustment of utility allowances. In connection with annual and special adjustments of contract rents, the owner must submit an analysis of the project's Utility Allowances. Such data as...

  6. 24 CFR 886.126 - Adjustment of utility allowances.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Adjustment of utility allowances... utility allowances. When the owner requests HUD approval of adjustment in Contract Rents under § 886.112, an analysis of the project's Utility Allowances must be included. Such data as changes in...

  7. 24 CFR 884.220 - Adjustment of utility allowances.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Adjustment of utility allowances... Adjustment of utility allowances. In connection with annual and special adjustments of contract rents, the owner must submit an analysis of the project's Utility Allowances. Such data as changes in utility...

  8. 50 CFR 665.127 - Allowable gear and gear restrictions.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Allowable gear and gear restrictions. 665... Fisheries § 665.127 Allowable gear and gear restrictions. (a) American Samoa coral reef ecosystem MUS may be taken only with the following allowable gear and methods: (1) Hand harvest; (2) Spear; (3) Slurp gun;...

  9. 50 CFR 665.427 - Allowable gear and gear restrictions.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Allowable gear and gear restrictions. 665... Archipelago Fisheries § 665.427 Allowable gear and gear restrictions. (a) Mariana coral reef ecosystem MUS may be taken only with the following allowable gear and methods: (1) Hand harvest; (2) Spear; (3)...

  10. 50 CFR 665.227 - Allowable gear and gear restrictions.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Allowable gear and gear restrictions. 665... Fisheries § 665.227 Allowable gear and gear restrictions. (a) Hawaii coral reef ecosystem MUS may be taken only with the following allowable gear and methods: (1) Hand harvest; (2) Spear; (3) Slurp gun;...

  11. 46 CFR 154.412 - Cargo tank corrosion allowance.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Cargo tank corrosion allowance. 154.412 Section 154.412... Containment Systems § 154.412 Cargo tank corrosion allowance. A cargo tank must be designed with a corrosion...) carries a cargo that corrodes the tank material. Note: Corrosion allowance for independent tank type C...

  12. 46 CFR 54.25-5 - Corrosion allowance.

    Science.gov (United States)

    2010-10-01

    ... Construction With Carbon, Alloy, and Heat Treated Steels § 54.25-5 Corrosion allowance. The corrosion allowance must be as required in 46 CFR 54.01-35. ... 46 Shipping 2 2010-10-01 2010-10-01 false Corrosion allowance. 54.25-5 Section 54.25-5...

  13. Factors affecting the carbon allowance market in the US

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyun Seok; Koo, Won W. [Center for Agricultural Policy and Trade Studies, Department of Agribusiness and Applied Economics, North Dakota State University, Dept 7610, P.O. Box 6050, Fargo, ND 58103-6050 (United States)

    2010-04-15

    The US carbon allowance market has different characteristic and price determination process from the EU ETS market, since emitting installations voluntarily participate in emission trading scheme. This paper examines factors affecting the US carbon allowance market. An autoregressive distributed lag model is used to examine the short- and long-run relationships between the US carbon allowance market and its determinant factors. In the long-run, the price of coal is a main factor in the determination of carbon allowance trading. In the short-run, on the other hand, the changes in crude oil and natural gas prices as well as coal price have significant effects on carbon allowance market. (author)

  14. 500 KV同塔四回线路不全停运检修作业方式研究%Study on Circuit Service Without Total Outage of the 500 kV Transmission Line of Four Circuits on One Tower

    Institute of Scientific and Technical Information of China (English)

    金逸; 肖匀; 刘庭; 刘凯; 肖宾

    2012-01-01

    In order to provide a technical basis for circuit service without total outage of the 500 kV transmission line of four circuits on one lower, the induced voltage of outage circuits were calculated by simulation under the condition of two circuits operating while the other two outage, or three circuits operating while the other one outage. The calculation resull indicates that when the two ends of outage circuits is ungrounded, the max peak value of the induced voltage of outage circuits can reach as high as 105 kV; when the two ends of outage circuits is grounded, the max peak value of the induced voltage of outage circuits can also reach as high as 95 V. It is proposed that, when the 500 kV four circuits on one tower is incomplete outage, the service operatinn can be live working, or power-off working with safety protective measures.%为了给500 kV同塔四回线路不全停运时的检修作业提供技术依据,通过仿真计算的方法,分别计算了 500 kV同塔四回线路,在两回运行两回停运、三回运行一回停运的情况下,在停运回路上的感应电压情况.计算结果发现,在500 kV同塔四回线路不全停运时,在停运线路两端均不接地的情况下,停运线路上的感应电压峰值最大可达105kV;在停运线路两端均接地的情况下,停运线路上的感应电压峰值最大可达95 V.根据计算及分析结果,提出了 500 kV同塔四回线路不全停运时的检修作业可采用带电作业方式或停电作业方式并需采取相应的安全防护措施.

  15. Simulation analysis on influences of Gansu-Ningxia section multiple loop interconnector outage on system stability%甘-宁断面多回联络线停电对系统稳定性的影响

    Institute of Scientific and Technical Information of China (English)

    顾雨嘉; 项丽; 耿天翔; 田蓓

    2014-01-01

    针对目前宁夏电网存在甘-宁断面多回联络线停电检修的现状,通过对甘-宁断面三回联络线进行停电方式下系统的热稳定、静态稳定、暂态稳定、动态稳定和小干扰稳定仿真计算分析,确定甘-宁断面在薄弱方式下对系统的稳定性影响。结果表明:甘-宁断面在多回联络线停电检修方式下对系统的稳定性影响较大,需对甘-宁断面采取预控措施,防止热稳定和动态稳定问题的发生。%Ningxia Power Grid currently exists the status quo of Gansu-Ningxia section multiple loop interconnector outage maintenance,by simulation and calculation analysis on system’s thermal stability,static stability,transient stability,dynamic stability and little interference stability under the mode of Gansu-Ningxia section triple loop interconnector outage, confirms the stability influence of Gansu-Ningxia section on system under weak mode. The result shows that Gansu-Ningxia section has larger influence on system stability under the mode of multiple loop interconnector outage maintenance,needs to take prevention measures for Gansu-Ningxia section, prevents the problem of thermal stability and dynamic statility to occur.

  16. 基于开断灵敏度的静态交全分析辅助决策%Assistant Decision-Making for Static Security Analysis Based on Outage Sensitivity

    Institute of Scientific and Technical Information of China (English)

    於益军; 刘俊; 冯树海; 李峰; 张哲; 张勇

    2013-01-01

    详细阐述了静态安全分析辅助决策的快速计算方法.在常规灵敏度算法的基础上,提出了计算支路开断分布因子的方法,并利用基态潮流方式下的灵敏度及开断分布因子,快速计算设备开断以后的节点注入功率对支路功率的开断灵敏度.依据开断灵敏度等量配对法原理,按照每台发电机对越限支路灵敏度和最大缓解量进行排序,形成辅助决策表辅助决策过程只是在原有网络分析基础上增加了少量的计算,计算过程能够满足在线应用要求,实际系统的验算结果证明了方法的正确性.%The algorithm of assistant decision-making for static security analysis is described in the paper. Based on the conventional sensitivity method, a new method is introduced to calculate outage distribution factors and the outage sensitivity which can reflect the relationship between node power and branch power after an element is out of service. Assistant decision-making for static security analysis can be easily acquired with the help of equal and opposite quantities in pairs for strategy of outage sensitivity. The assistant decision-making can satisfy the requirement of on-line application. Simulation results on real power system show that the proposed method is effective.

  17. 物理层网络编码机会中继及中断性能分析%Opportunistic Relaying and Outage Analysis for Physical-layer Network Coding

    Institute of Scientific and Technical Information of China (English)

    吉晓东; 郑宝玉

    2011-01-01

    该文研究了频率非选择性瑞利衰落信道中的物理层网络编码系统容量问题.基于放大转发机制提出了一种基于最大最小互信息准则的机会中继策略.在瑞利衰落信道环境下,从双向通信的角度,通过理论分析得出其中断概率解析式,同时推导了理想物理层网络编码和传统直接传输系统的中断概率解析式.通过理论分析,发现在某些节点发射功率条件下,系统中断概率将完全取决于单向链路.在此基础上完成了数值仿真实验,结果表明所提策略的中断性能与理想物理层网络编码和传统直接传输相比有了显著的提高.%The capacity issue of Physical-layer Network Coding (PNC) is investigated. According to the Max-Min Mutual Information (MMMI) criterion, a new opportunistic relaying scheme is proposed based on Amplify-and-Forward (AF). Then, the outage probability expressions are derived for the new proposed scheme as well as the schemes of ideal PNC and traditional direct transmission in frequency-nonselective Rayleigh fading channels. By the analysis, it is found that the system outage performance can be measured by one-way channel in some conditions, which are determined by the node transmission powers. Simulation results show that the outage performance is improved significantly when MMMI strategy is used.

  18. Evaluation of potential severe accidents during low power and shutdown operations at Grand Gulf, Unit 1. Volume 5: Analysis of core damage frequency from seismic events for plant operational state 5 during a refueling outage

    Energy Technology Data Exchange (ETDEWEB)

    Budnitz, R.J. [Future Resources Associates, Inc., Berkeley, CA (United States); Davis, P.R. [PRD Consulting (United States); Ravindra, M.K.; Tong, W.H. [EQE International, Inc., Irvine, CA (United States)

    1994-08-01

    In 1989 the US Nuclear Regulatory Commission (NRC) initiated an extensive program to examine carefully the potential risks during low-power and shutdown operations. The program included two parallel projects, one at Sandia National Laboratories studying a boiling water reactor (Grand Gulf), and the other at Brookhaven National Laboratory studying a pressurized water reactor (Surry Unit 1). Both the Sandia and Brookhaven projects have examined only accidents initiated by internal plant faults---so-called ``internal initiators.`` This project, which has explored the likelihood of seismic-initiated core damage accidents during refueling outage conditions, is complementary to the internal-initiator analyses at Brookhaven and Sandia. This report covers the seismic analysis at Grand Gulf. All of the many systems modeling assumptions, component non-seismic failure rates, and human effort rates that were used in the internal-initiator study at Grand Gulf have been adopted here, so that the results of the study can be as comparable as possible. Both the Sandia study and this study examine only one shutdown plant operating state (POS) at Grand Gulf, namely POS 5 representing cold shutdown during a refueling outage. This analysis has been limited to work analogous to a level-1 seismic PRA, in which estimates have been developed for the core-damage frequency from seismic events during POS 5. The results of the analysis are that the core-damage frequency for earthquake-initiated accidents during refueling outages in POS 5 is found to be quite low in absolute terms, less than 10{sup {minus}7}/year.

  19. Carbon nanohorns allow acceleration of osteoblast differentiation via macrophage activation

    Science.gov (United States)

    Hirata, Eri; Miyako, Eijiro; Hanagata, Nobutaka; Ushijima, Natsumi; Sakaguchi, Norihito; Russier, Julie; Yudasaka, Masako; Iijima, Sumio; Bianco, Alberto; Yokoyama, Atsuro

    2016-07-01

    Carbon nanohorns (CNHs), formed by a rolled graphene structure and terminating in a cone, are promising nanomaterials for the development of a variety of biological applications. Here we demonstrate that alkaline phosphatase activity is dramatically increased by coculture of human monocyte derived macrophages (hMDMs) and human mesenchymal stem cells (hMSCs) in the presence of CNHs. CNHs were mainly localized in the lysosome of macrophages more than in hMSCs during coculturing. At the same time, the amount of Oncostatin M (OSM) in the supernatant was also increased during incubation with CNHs. Oncostatin M (OSM) from activated macrophage has been reported to induce osteoblast differentiation and matrix mineralization through STAT3. These results suggest that the macrophages engulfed CNHs and accelerated the differentiation of mesenchymal stem cells into the osteoblast via OSM release. We expect that the proof-of-concept on the osteoblast differentiation capacity by CNHs will allow future studies focused on CNHs as ideal therapeutic materials for bone regeneration.Carbon nanohorns (CNHs), formed by a rolled graphene structure and terminating in a cone, are promising nanomaterials for the development of a variety of biological applications. Here we demonstrate that alkaline phosphatase activity is dramatically increased by coculture of human monocyte derived macrophages (hMDMs) and human mesenchymal stem cells (hMSCs) in the presence of CNHs. CNHs were mainly localized in the lysosome of macrophages more than in hMSCs during coculturing. At the same time, the amount of Oncostatin M (OSM) in the supernatant was also increased during incubation with CNHs. Oncostatin M (OSM) from activated macrophage has been reported to induce osteoblast differentiation and matrix mineralization through STAT3. These results suggest that the macrophages engulfed CNHs and accelerated the differentiation of mesenchymal stem cells into the osteoblast via OSM release. We expect that the

  20. Real-Time Distribution Feeder Performance Monitoring, Advisory Control, and Health Management System

    Energy Technology Data Exchange (ETDEWEB)

    Stoupis, James; Mousavi, Mirrasoul

    2014-09-30

    New data collection system equipment was installed in Xcel Energy substations and data was collected from 6 substations and 20 feeders. During Phase I, ABB collected and analyzed 793 real-time events to date from 6 Xcel Energy substations and continues today. The development and integration of several applications was completed during the course of this project, including a model-based faulted segment identification algorithm, with very positive results validated with field-gathered data discussed and included in this report. For mostly underground feeders, the success rate is 90% and the overreach rate is 90%. For mostly overhead feeders, the success rate is 74% and the overreach rate is 50%. The developed method is producing very accurate results for mostly underground feeders. For mostly overhead feeders, due to the bad OMS data quality and varying fault resistance when arcing, the developed method is producing good results but with much room for improvement. One area where the algorithm can be improved is the accuracy for sub-cycle fault events. In these cases, the accuracy of the conventional signal processing methods suffers due to most of these methods being based on a one-cycle processing window. By improving the signal processing accuracy, the accuracy of the faulted segment identification algorithm will also improve significantly. ABB intends to devote research in this area in the near future to help solve this problem. Other new applications developed during the course of the project include volt/VAR monitoring, unbalanced capacitor switching detection, unbalanced feeder loading detection, and feeder overloading detection. An important aspect of the demonstration phase of the project is to show the ability to provide adequate “heads-up” time ahead of customer calls or AMI reports so that the operators are provided with the much needed time to collect information needed to address an outage. The advance notification feature of the demonstration system

  1. System Downlink Outage Probability Analysis in Distributed Antenna Systems%分布式天线系统中的系统下行中断概率分析

    Institute of Scientific and Technical Information of China (English)

    王俊波; 王金元; 陈华敏; 陈明

    2011-01-01

    The main focus of this paper is to investigate the system downlink outage probability in distributed antenna systems (DAS).Firstly,this paper establishes a comtposite channel model which takes into account three factors such as path loss,lognormal shadowing and Rayleigh fading. Then, by making use of the moment generating function (MGF), this paper derives the probability density function (PDF) of the output signal-to-noise ratio (SNR) after maximal ratio combining (MRC) at the receiver.After that,an approximate analytical expression of the outage probability for a mobile station (MS) over a given position is derived with an antenna selective transmission (ST) scheme. Further, considering the distribution of MSs in the system, a closed-form expression of the system outage probability is obtained. Numerical results show that the closed-form expression can provide sufficient precision for evaluating the outage probability performance of DAS.%本文针对分布式天线系统的系统下行中断概率问题展开研究.文章首先建立了包含路径损耗、阴影衰落和瑞利衰落的复合信道模型.接着,在接收端采用最大比合并的方式接收信号,并运用矩生成函数推导出输出信噪比的概率密度函数.然后,对分布式天线采用选择传输策略,并分析出给定移动台位置时的中断概率的表达式.最后,考虑小区内移动台任意分布特点,进一步推导出系统下行中断概率闭合表达式.仿真结果表明,所推导的闭合表达式能准确地评估系统中断概率性能.

  2. Ad hoc系统中基于中断概率边界的博弈功率控制算法%Power control game based on outage bound probabilities in Ad hoc systems

    Institute of Scientific and Technical Information of China (English)

    蔡跃明; 喻的雄; 吴丹; 胡均权

    2011-01-01

    By analyzing the outage probability of the Ad hoc systems on Rayleigh fading channel, the upper bound and lower bound of the outage probability were given in this paper.Then two power control functions were designed based on these two bounds to seek the minimum transmit power for minimum upper bound and lower bound.The existence and uniqueness of the two functions were proved and the power updating algorithms proposed.In the end, the performance analysis of the convergence and power consumer of these two functions was shown by simulation.It can be found that if the power cost factor is set to the critical point at which the convergent property of LC (Cost function based on lower bound called LC for simplicity) can be sustained, then the minimum outage probability can be obtained and this approach can reduce the complexity better than using outage probability to design the cost function directly.%通过对瑞利衰落信道下Ad hoc系统中断概率的分析,给出了中断概率的上界和下界,并以此为依据设计出结构类型相似的2个博弈功率控制函数,从而求得中断概率最小时的功率发射值.同时证明了所设计的2个博弈功率控制函数的纳什均衡存在且唯一,并给出了获得纳什均衡的功率更新算法.仿真结果表明,提出的算法能够有效地逼近中断概率,且较DPC算法而言,可以通过设置不同的功率参数因子而获得更大的灵活性.

  3. Power grid outage fault diagnosis method based on distributed characteristics of power flow variation%基于潮流变化量特征的电网开断故障诊断方法研究

    Institute of Scientific and Technical Information of China (English)

    罗杰; 蒋铁铮; 刘鸣春

    2015-01-01

    Traditional diagnosis method of fault power grid based on the action information of pro-tective relays and breakers may have some uncertain factors that have the influence on the accura-cy,such as mal-operation,miss trip in the practical application.A novel method based on con-ventional power flow information of each branch acquired by SCADA was applied to diagnose branch outage fault in this paper.Firstly,branch outage fault pattern sets of the whole power grid were established by branch outage distribution factor.Conventional power flow variations caused by the power grid faults were extracted.Finally,matching recognition for the fault branch was carried out by pattern recognition algorithm.Case study on an actual power system was car-ried out.The results showed that the proposed method could diagnose the outage fault of power system branch rapidly and have application value for engineering.%传统的基于保护、开关动作信息的电网故障诊断方法在实际应用中存在误动和拒动。利用 SCADA 系统采集的电网支路稳态潮流信息作为诊断依据,提出一种电网支路开断故障诊断的新方法,利用支路开断分布因子建立全网支路开断故障模式集,提取电网发生故障后各支路稳态潮流变化量,并运用模式识别算法对电网故障支路进行匹配识别,实现电网开断故障诊断。对某区域电网实例数据进行仿真分析,结果表明:该方法能够有效地对电网支路开断故障进行快速诊断,具有较好的工程实用价值。

  4. 非对称双向多中继系统机会式网络编码中断概率分析%Outage Probability Analysis of Opportunistic Network Coding on Asymmetrical Bi-directional Multi-Relay System

    Institute of Scientific and Technical Information of China (English)

    梁文文; 田华; 徐友云; 许魁; 陈小杰

    2013-01-01

    A practical asymmetrical bi-directional multi-relay system model is firstly constructed, and then an outage probability expression of the model is given based on opportunistic relay scheme and network coding, which is proved accurate by Monte Carlo simulations. Secondly, it analyzes the system average outage probability with different situations of power allocation coefficient, locations of the relay nodes and the number of relay nodes, indicating the inherent relationship between power allocation coefficient and total system power, as well as the number of relay nodes. Simulation results show that the optimal system outage performance of asymmetrical bi-directional multi-relay system based on opportunistic relay scheme and network coding is attained when power allocation coefficient is chosen at 0. 6 or about 0. 6. It can be known that the location of relay nodes is an important factor for the problem of system outage probability.%建立了一个实际的非对称双向多中继系统模型,并采用机会中继策略,推导出了该模型在译码转发方式下采用网络编码时的中断概率表达式,Monte Carlo仿真和理论值吻合,充分验证了该表达式的正确性.分析了不同中继节点位置、不同中继节点个数和不同功率分配因子等情况下的系统中断性能,揭示了最优功率分配因子与中继节点个数和位置以及系统总功率的内在关系.仿真结果表明,在非对称双向多中继系统中同时采用网络编码和机会中继策略时,功率分配因子取值为0.6时可获得最佳的系统中断性能,并指出在研究系统中断概率问题时,中继节点位置是一个不可忽略的因素.

  5. 基于路径中断概率的VANETs连接模型及性能分析%Path outage probability-based VANETs connection model and performance analysis

    Institute of Scientific and Technical Information of China (English)

    汪颖; 张堑

    2014-01-01

    车载网VANETs(Vehicular Ad hoc Networks)在道路安全、车流量管理和娱乐应用具有广阔的前景,而这些应用依赖数据有效的传输。为此,VANETs的数据传输技术成为研究的焦点。然而,VANETs的拓扑动态变化、车辆快速移动加速了车间通信链路的断裂,降低了链路的可靠性,为数据有效传输提出了挑战。据此,分析了VANETs的多跳通信连接特性。通过研究端到端中断概率,提出多跳连接的分析模型。通过模型,可得出在一定的平均端到端中断概率所需的最小发射功率以及最大传输跳数。通过仿真,验证理论模型的正确性。仿真进一步表明,通过合适的功率控制算法有利于改善数据传输路径。%Data transmission technology in VANETs(Vehicular Ad-hoc Networks)obtains more attention since that VANETs is able to provide road safety, vehicle traffic management and infotainment service. However, the changed topology and fast moving vehicle accelerate the fracture of communication link between vehicles, and reduce the reliability of commu-nication links. Therefore,the multi-hop connectivity properties of VANETs based on a physical layer based Quality of Ser-vice(QoS)criterion in terms of average end-to-end path outage probability are analyzed.Under this approach, a multi-hop path joining a pair of vehicles is considered to be connected if and only if the average end-to-end path outage probability meets a target requirement. An analytical model to compute the average end-to-end path outage probability of a connected path is presented. This paper then investigates the minimum transmit power and maximum number of hops satisfying an average path outage probability constraint. The validity of the theoretical analysis is verified by simulation.Simulation results show that a suitable power control algorithm can improve the data transmission path.

  6. Real-time precision pedestrian navigation solution using Inertial Navigation System and Global Positioning System

    Directory of Open Access Journals (Sweden)

    Yong-Jin Yoon

    2015-03-01

    Full Text Available Global Positioning System and Inertial Navigation System can be used to determine position and velocity. A Global Positioning System module is able to accurately determine position without sensor drift, but its usage is limited in heavily urbanized environments and heavy vegetation. While high-cost tactical-grade Inertial Navigation System can determine position accurately, low-cost micro-electro-mechanical system Inertial Navigation System sensors are plagued by significant errors. Global Positioning System is coupled with Inertial Navigation System to correct the errors, while Inertial Navigation System itself can be used to provide navigation solution during a Global Positioning System outage. Data from Global Positioning System and Inertial Navigation System can be integrated by extensive Kalman filtering, using loosely coupled integration architecture to provide navigation solutions. In this study, real-time low-cost loosely coupled micro-electro-mechanical system Inertial Navigation System/Global Positioning System sensors have been used for pedestrian navigation. Trial runs of Global Positioning System outages have been conducted to determine the accuracy of the system described. The micro-electro-mechanical system Inertial Navigation System/Global Positioning System can successfully project a trajectory during a Global Positioning System outage and produces a root mean square error of 9.35 m in latitude direction and 10.8 m in longitude direction. This technology is very suitable for visually impaired pedestrians.

  7. 29 CFR 778.600 - Veterans' subsistence allow- ances.

    Science.gov (United States)

    2010-07-01

    ... OF GENERAL POLICY OR INTERPRETATION NOT DIRECTLY RELATED TO REGULATIONS OVERTIME COMPENSATION... subsistence allowances provided by Public Law 346 for payment to veterans are not paid as compensation...

  8. The flipped classroom allows for more class time devoted to critical thinking.

    Science.gov (United States)

    DeRuisseau, Lara R

    2016-12-01

    The flipped classroom was utilized in a two-semester, high-content science course that enrolled between 50 and 80 students at a small liberal arts college. With the flipped model, students watched ~20-min lectures 2 days/wk outside of class. These videos were recorded via screen capture and included a detailed note outline, PowerPoint slides, and review questions. The traditional format included the same materials, except that lectures were delivered in class each week and spanned the entire period. During the flipped course, the instructor reviewed common misconceptions and asked questions requiring higher-order thinking, and five graded case studies were performed each semester. To determine whether assessments included additional higher-order thinking skills in the flipped vs. traditional model, questions across course formats were compared via Blooms Taxonomy. Application-level questions that required prediction of an outcome in a new scenario comprised 38 ± 3 vs. 12 ± 1% of summative assessment questions (classroom) compared with their major GPA. These data demonstrate that assessments transitioned to more application-level compared with factual knowledge-based questions with this particular flipped model, and students performed better in their final letter grade compared with the traditional lecture format. Although the benefits to a flipped classroom are highlighted, student evaluations did suffer. More detailed studies comparing the traditional and flipped formats are warranted.

  9. 9 CFR 51.32 - Claims not allowed.

    Science.gov (United States)

    2010-01-01

    ... COOPERATIVE CONTROL AND ERADICATION OF LIVESTOCK OR POULTRY DISEASES ANIMALS DESTROYED BECAUSE OF BRUCELLOSIS Indemnity for Sheep, Goats, and Horses § 51.32 Claims not allowed. Claims for indemnity for goats, sheep, and horses destroyed because of brucellosis will not be allowed if any of the following...

  10. 38 CFR 21.9670 - Work-study allowance.

    Science.gov (United States)

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Work-study allowance. 21... rate of pursuit of at least 75 percent may receive a work-study allowance in accordance with the...) VOCATIONAL REHABILITATION AND EDUCATION Post-9/11 GI Bill Payments-Educational Assistance § 21.9670...

  11. 26 CFR 31.3402(m)-1 - Withholding allowances.

    Science.gov (United States)

    2010-04-01

    ... individuals. (i) Except as provided in subdivision (ii) of this subparagraph, a husband and wife shall... of their combined wages and allowable items. The withholding allowances to which a husband and wife are entitled may be claimed by the husband, by the wife, or they may be allocated between...

  12. 49 CFR 174.86 - Maximum allowable operating speed.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Maximum allowable operating speed. 174.86 Section... operating speed. (a) For molten metals and molten glass shipped in packagings other than those prescribed in § 173.247 of this subchapter, the maximum allowable operating speed may not exceed 24 km/hour (15...

  13. 40 CFR 86.1725-01 - Allowable maintenance.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 19 2010-07-01 2010-07-01 false Allowable maintenance. 86.1725-01... Trucks § 86.1725-01 Allowable maintenance. This section includes text that specifies requirements that... are subject to the applicable Otto-cycle or diesel engine maintenance requirements of §...

  14. 20 CFR 362.10 - Principal types of claims allowable.

    Science.gov (United States)

    2010-04-01

    ... which the loss or damage occurred: (1) In a common or natural disaster; (2) When the property was... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false Principal types of claims allowable. 362.10... PROCEDURES EMPLOYEES' PERSONAL PROPERTY CLAIMS § 362.10 Principal types of claims allowable. (a) In...

  15. 24 CFR 882.510 - Adjustment of utility allowance.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Adjustment of utility allowance... Moderate Rehabilitation-Program Development and Operation § 882.510 Adjustment of utility allowance. The PHA must determine, at least annually, whether an adjustment is required in the Utility...

  16. 24 CFR 891.645 - Adjustment of utility allowances.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Adjustment of utility allowances... Handicapped-Section 8 Assistance § 891.645 Adjustment of utility allowances. In connection with adjustments of contract rents as provided in § 891.640(a), the requirements for the adjustment of utility...

  17. 24 CFR 982.517 - Utility allowance schedule.

    Science.gov (United States)

    2010-04-01

    ... reasonable accommodation in accordance with 24 CFR part 8 to make the program accessible to and usable by the... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Utility allowance schedule. 982.517... Payment § 982.517 Utility allowance schedule. (a) Maintaining schedule. (1) The PHA must maintain...

  18. 77 FR 66938 - Utility Allowances Submetering; Hearing Cancellation

    Science.gov (United States)

    2012-11-08

    ... Federal Register on August 7, 2012 (77 FR 46987) announced that a public hearing was scheduled for... Internal Revenue Service 26 CFR Part 1 RIN 1545-BI91 Utility Allowances Submetering; Hearing Cancellation... 42 of the Internal Revenue Code; relating to the utility allowance regulations. DATES: The...

  19. 42 CFR 489.31 - Allowable charges: Blood.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 5 2010-10-01 2010-10-01 false Allowable charges: Blood. 489.31 Section 489.31... Allowable charges: Blood. (a) Limitations on charges. (1) A provider may charge the beneficiary (or other person on his or her behalf) only for the first three pints of blood or units of packed red...

  20. 48 CFR 1352.216-70 - Estimated and allowable costs.

    Science.gov (United States)

    2010-10-01

    ... Estimated and allowable costs. As prescribed in 48 CFR 1316.307(a), insert the following clause: Estimated and Allowable Costs (APR 2010) (a) Estimated Costs. The estimated cost of this contract is... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Estimated and...

  1. 浅谈地区电网设备停电检修的运行方式策划%About the operation mode analysis of the equipment outage for the re-gional power grids

    Institute of Scientific and Technical Information of China (English)

    蔡璐璇

    2014-01-01

    Power equipment maintenance is an important part of safety in production of power system, the reasonable operation mode is the key point of the safe operation of power grids and power supply reliability during equipment outages. In the face of increasingly large power grids, the operation mode analysis decision system of equipment outage can improve personnel's working efficiency and rationality of science planning results, to ensure the safe operation of power grids.%电网设备停电检修是电力系统安全生产的一个重要环节,保障设备停电检修期间的电网安全运行和供电可靠性关键在于合理的运行方式策划。面对日益庞大的电网,设备停电运行方式策划分析系统可以提高方式人员的工作效率及策划结果的科学合理性,保证电网安全运行。

  2. 试分析配电自动化对配网不停电作业安全的影响%Analysis on the Influence of Power Distribution Automation to the Security of Distribution Network Non Outage Operation

    Institute of Scientific and Technical Information of China (English)

    隗笑; 侯莉媛; 高永强

    2016-01-01

    Blackout overhaul will be larger effects on the user's normal power, no power outage maintenance is a kind of effective measures to keep the power supply is normal, in order to guarantee the safety of no power operation, need to introduce distribution automation technology. Based on the actual project as an example of the power distribution between the characteristics were analyzed, and then the optimized retroift scheme of the distribution network was introduced. Finally, the distribution automation of distribution network power outage operation safety effect were analyzed.%停电检修会对用户的正常用电造成比较大的影响,不停电检修是一种保持供电正常的有效措施,为了保证不停电作业的安全性,需要积极引入配电自动化技术。文章以实际工程为例对配电带电作业特点进行了分析,然后介绍了配电网的优化改造方案,最后对配电自动化对配网不停电作业安全影响进行了分析。

  3. Analysis and Countermeasures for 1 000 MW Unit Condensate Polishing Mixed-bed Resin Running during Commissioning and Outage%1000MW机组凝结水精处理混床投停时跑树脂分析

    Institute of Scientific and Technical Information of China (English)

    黄校春

    2012-01-01

    凝结水精处理混床在投退过程中发生跑树脂的问题严重影响混床的安全、经济、稳定运行。文章简要介绍了某1 000 MW超超临界机组凝结水精处理混床系统,分析了凝结水精处理混床投退过程中发生的跑树脂问题及产生的原因,提出了相应对策,为大型电厂凝结水精处理系统解决类似问题提供了参考。%Condensate polishing mixed bed resin running during commissioning and outage seriously affect the safe, economic and stable operation of mixed bed. This paper briefly introduced the 1 000 MW ultra-supercritical units condensate polishing mixed bed system, analyzed the problem and cause of condensate polishing mixed-bed resin running cecurred during commissioning and outage, proposed countermeasures, and provided reference to large power plants to solve similar problems of condensate polishing system.

  4. 计及用户停电损失的离网光伏与储能系统优化规划%Optimal Planning of Standalone Photovoltaic and Energy Storage System Considering Customer Outage Cost

    Institute of Scientific and Technical Information of China (English)

    余贻鑫; 孙冰

    2016-01-01

    离网运行的光伏与储能系统的投资,即所需安装的光伏和储能的容量,不仅取决于用户负荷需求的大小,而且与用户对供电可靠性的要求以及系统的控制策略密切相关。为合理计及可靠性成本,通过用户停电损失指标把可靠性货币化,不仅可以通过该指标确定负荷的供电优先级,而且便于以总成本最小为目标进行优化规划。提出了一种具有时间前瞻性的控制策略,该策略的特点是:在储能充电阶段进行前瞻性充电,以保证储能可以在放电阶段向供电优先级高的负荷供电,使用户总成本最小;通过嵌套全生命周期 Monte Carlo 模拟的广度优先搜索策略,迅速锁定最优规划方案。通过算例证明了所提控制策略的优势和规划方法的有效性。%The investment in standalone photovoltaic and energy storage system,or the required installation capacity of photovoltaic and energy storage,is affected by many factors.Customer’s demand size is an obvious factor,while the power supply reliability requirement and system control strategy are also important but easily overlooked fac-tors.Firstly,to account for the reliability cost reasonably,customer outage cost is selected to monetize reliability index in the paper.In this way,the load priority is decided naturally,hence laying a solid foundation for the optimal planning whose target is minimizing the total cost.Then,a novel control strategy with prospective timing is put for-ward.With the strategy,storage system is charged prospectively during the charging stage to ensure that the high priority load can be supplied.In doing so,customer’s total cost is minimized.Lastly,breadth-first search nested by life-cycle Monte Carlo simulation is used to pick up the best planning scheme.A case study is conducted to verify the effectiveness of planning method and the advantage of control strategy.

  5. 7 CFR 52.782 - Allowances for quality factors.

    Science.gov (United States)

    2010-01-01

    ... PROCESSED FOOD PRODUCTS 1 United States Standards for Grades of Canned Red Tart Pitted Cherries 1 Allowances... average 1 per 30 ozs 4 or more in any sample unit Sample average 1 per 20 ozs. Defects: 100 cherries...

  6. 45 CFR 1386.25 - Allowable litigation costs.

    Science.gov (United States)

    2010-10-01

    ..., DEVELOPMENTAL DISABILITIES PROGRAM FORMULA GRANT PROGRAMS State System for Protection and Advocacy of the Rights... be used to pay the otherwise allowable costs incurred by a Protection and Advocacy System in...

  7. 50 CFR 665.627 - Allowable gear and gear restrictions.

    Science.gov (United States)

    2010-10-01

    ..., Johnston Atoll and Palmyra Atoll. (d) Existing FEP fisheries shall follow the allowable gear and methods... decision on the permissibility of this gear type will be made by the Regional Administrator...

  8. The Use of NASA near Real-time and Archived Satellite Data to Support Disaster Assessment

    Science.gov (United States)

    McGrath, Kevin M.; Molthan, Andrew; Burks, Jason

    2014-01-01

    With support from a NASA's Applied Sciences Program, The Short-term Prediction Research and Transition (SPoRT) Center has explored a variety of techniques for utilizing archived and near real-time NASA satellite data to support disaster assessment activities. MODIS data from the NASA Land Atmosphere Near Real-time Capability for EOS currently provides true color and other imagery for assessment and potential applications including, but not limited to, flooding, fires, and tornadoes. In May 2013, the SPoRT Center developed unique power outage composites using the VIIRS Day/Night Band to represent the first clear sky view of damage inflicted upon Moore and Oklahoma City, Oklahoma following the devastating EF-5 tornado that occurred on May 20. Pre-event imagery provided by the NASA funded Web-Enabled Landsat Data project offer a basis of comparison for monitoring post-disaster recovery efforts. Techniques have also been developed to generate products from higher resolution imagery from the recently available International Space Station SERVIR Environmental Research and Visualization System instrument. Of paramount importance is to deliver these products to end users expeditiously and in formats compatible with Decision Support Systems (DSS). Delivery techniques include a Tile Map Service (TMS) and a Web Mapping Service (WMS). These mechanisms allow easy integration of satellite products into DSS's, including the National Weather Service's Damage Assessment Toolkit for use by personnel conducting damage surveys. This poster will present an overview of the developed techniques and products and compare the strengths and weaknesses of the TMS and WMS.

  9. ACCOUNTING FOR GREENHOUSE GASES EMISSIONS ALLOWANCES IN ROMANIA

    Directory of Open Access Journals (Sweden)

    Marius Deac

    2013-02-01

    Full Text Available The present paper tries to analyze the accounting challenges that the implementation of EU Emissions Trading Scheme has risen. On 2 December 2004, IASB has issued an interpretation regarding the accounting of the GHG emissions allowances (IFRIC 3 „Emission Rights”. This interpretation should have been effective for annual periods beginning after 1 March 2005, the first year of the EU Emission Trading Scheme implementation. Less than a year after it was issued, IFRIC has withdrawn IFRIC 3. In December 2007, IASB has started a new project in order to provide guidance on accounting for carbon allowances called Emissions Trading Schemes Project. In the absence of an accounting standard regarding the accounting of these emissions allowances a diversity of accounting practices have been identified. Nowadays, there are three main accounting practices for the recognition of the emissions allowances and the GHG emissions liabilities: IFRIC 3 approach, the government grants approach and the net liability or off balance sheet approach. The accounting treatment of greenhouse gas emissions allowances by Romanian companies resembles the net liability or off balance sheet approach. Finance Ministry Order no. 1118/2012 states that GHG emission certificates should be recognized as fixed assets (if the entity is expecting a profit in the long term or in the category of short term investments (if the entity is expecting a profit in the short term. The accounting of the greenhouse gas emissions allowances described above is applicable mainly to traders of such certificates and not for the installations in the scope of the EU ETS directive, which should recognize GHG emissions off balance sheet, at their nominal value (nil if received for free. The shortfall or excess of allowances will be recognized in the profit or loss as they are bought or sold by the entity (the accounting treatment imposed by Finance Ministry Order no. 3055/2009.

  10. Evaluation of potential severe accidents during low power and shutdown operations at Grand Gulf, Unit 1: Analysis of core damage frequency from internal events for Plant Operational State 5 during a refueling outage. Volume 2, Part 3: Internal Events Appendices I and J

    Energy Technology Data Exchange (ETDEWEB)

    Yakle, J. [Science Applications International Corp., Albuquerque, NM (United States); Darby, J. [Science and Engineering Associates, Inc., Albuquerque, NM (United States); Whitehead, D.; Staple, B. [Sandia National Labs., Albuquerque, NM (United States)

    1994-06-01

    This report provides supporting documentation for various tasks associated with the performance of the probablistic risk assessment for Plant Operational State 5 during a refueling outage at Grand Gulf, Unit 1 as documented in Volume 2, Part 1 of NUREG/CR-6143.

  11. 9 CFR 50.22 - Claims not allowed.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Claims not allowed. 50.22 Section 50.22 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE COOPERATIVE CONTROL AND ERADICATION OF LIVESTOCK OR POULTRY DISEASES ANIMALS DESTROYED BECAUSE OF...

  12. 34 CFR 390.41 - What are allowable costs?

    Science.gov (United States)

    2010-07-01

    ... conduct of the seminar, institute, workshop or other short course for which the grant support has been... AND REHABILITATIVE SERVICES, DEPARTMENT OF EDUCATION REHABILITATION SHORT-TERM TRAINING What... costs established in EDGAR §§ 75.530-75.562, the following items are allowable under short-term...

  13. 40 CFR 18.8 - Stipends, Allowances, and Benefits.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Stipends, Allowances, and Benefits. 18.8 Section 18.8 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GENERAL ENVIRONMENTAL... continental United States, the payment of expenses of preparing the remains for burial and transporting...

  14. Disability and Supported Employment: Impact on Employment, Income, and Allowances

    Science.gov (United States)

    Germundsson, Per; Gustafsson, Johanna; Lind, Martin; Danermark, Berth

    2012-01-01

    In this article, we examine supported employment and its impact on the level of employment, disposable income, and sum of allowances, targeting a group of individuals with disabilities. We have particularly focused on individuals with psychiatric disabilities. Supported employment is a vocational rehabilitation service with an empowerment approach…

  15. Can preapproval jump-start the allowance market

    Energy Technology Data Exchange (ETDEWEB)

    Dudek, D.J.; Goffman, J.

    1992-06-01

    With compliance deadlines approaching in three years, utility, environmental and financial planners and their regulators are in the process of grappling with the requirements imposed, and opportunities created, by the acid rain program established under Title 4 of the Clean Air Act amendments of 1990. The novel element of the program - emissions or allowance trading through a nationwide allowance market - presents great challenges for utilities and their regulators. Perhaps the foremost challenge is establishing the allowance market. If state utility commissions subject utilities' compliance strategies to traditional after-the-fact prudence reviews, as tradition would impel them to do, the attendant regulatory risks are likely to push utilities toward more conservative compliance schemes that underuse allowance trading (as the exchange at the head of this article demonstrates). If that happens, the market will fail to develop, and its full potential for environmental benefit at least cost will go unrealized. This, in turn, is likely to strengthen the case for non-market regulatory mechanisms - a vicious circle. In this paper, the authors suggest a way out of this.

  16. Conditions allowing the formation of biogenic amines in cheese.

    NARCIS (Netherlands)

    Joosten, H.M.L.J.

    1988-01-01

    A study was undertaken to reveal the conditions that allow the formation of biogenic amines in cheese.The starters most commonly used in the Dutch cheese industry do not have decarboxylative properties. Only if the milk or curd is contaminated with non-starter bacteria, amine formation may be observ

  17. 48 CFR 752.7028 - Differential and allowances.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Differential and allowances. 752.7028 Section 752.7028 Federal Acquisition Regulations System AGENCY FOR INTERNATIONAL... compensation to an employee in a foreign area where civil insurrection, civil war, terrorism or...

  18. 30 CFR 206.261 - Transportation allowances-general.

    Science.gov (United States)

    2010-07-01

    ... quantity of clean coal output and the rejected waste material. The transportation allowance shall be... MANAGEMENT PRODUCT VALUATION Federal Coal § 206.261 Transportation allowances—general. (a) For ad valorem... the coal from a Federal lease to a sales point which is remote from both the lease and mine; or...

  19. 30 CFR 206.460 - Transportation allowances-general.

    Science.gov (United States)

    2010-07-01

    ... quantity of clean coal output and the rejected waste material. The transportation allowance shall be... MANAGEMENT PRODUCT VALUATION Indian Coal § 206.460 Transportation allowances—general. (a) For ad valorem... the coal from an Indian lease to a sales point which is remote from both the lease and mine; or...

  20. 30 CFR 206.262 - Determination of transportation allowances.

    Science.gov (United States)

    2010-07-01

    ... REVENUE MANAGEMENT PRODUCT VALUATION Federal Coal § 206.262 Determination of transportation allowances. (a... transporting the coal under that contract, subject to monitoring, review, audit, and possible future adjustment... are generally those for depreciable fixed assets (including costs of delivery and installation...

  1. 41 CFR 101-27.503 - Allowable credit.

    Science.gov (United States)

    2010-07-01

    ... 41 Public Contracts and Property Management 2 2010-07-01 2010-07-01 true Allowable credit. 101-27.503 Section 101-27.503 Public Contracts and Property Management Federal Property Management Regulations System FEDERAL PROPERTY MANAGEMENT REGULATIONS SUPPLY AND PROCUREMENT 27-INVENTORY MANAGEMENT...

  2. 20 CFR 322.7 - Dismissal, coordination, and separation allowances.

    Science.gov (United States)

    2010-04-01

    ... UNEMPLOYMENT INSURANCE ACT REMUNERATION § 322.7 Dismissal, coordination, and separation allowances. (a... relationship and remains subject to call. Such pay is remuneration with respect to each day in the month or... employee who voluntarily or involuntarily terminates his or her employment relationship is not...

  3. 20 CFR 429.203 - When is a claim allowable?

    Science.gov (United States)

    2010-04-01

    ... paragraph (a) of this section and the other provisions of this subpart, any claim you make for damage to, or... excluded under this subpart: (1) Property damage in quarters or other authorized places. Claims are allowable for damage to, or loss of, property arising from fire, flood, hurricane, other natural...

  4. 49 CFR 230.24 - Maximum allowable stress.

    Science.gov (United States)

    2010-10-01

    ..., DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Boilers and Appurtenances... allowable stress value on any component of a steam locomotive boiler shall not exceed 1/4 of the ultimate... construction in boiler calculations, the safety factor value shall not be less than 4....

  5. 44 CFR 11.74 - Claims not allowed.

    Science.gov (United States)

    2010-10-01

    ... 44 Emergency Management and Assistance 1 2010-10-01 2010-10-01 false Claims not allowed. 11.74 Section 11.74 Emergency Management and Assistance FEDERAL EMERGENCY MANAGEMENT AGENCY, DEPARTMENT OF..., checks, promissory notes, stock certificates, bonds, bills of lading, warehouse receipts, baggage...

  6. 38 CFR 21.332 - Payments of subsistence allowance.

    Science.gov (United States)

    2010-07-01

    ... payment only: (1) At the beginning of an ordinary school year; or (2) At the beginning of any other....C. 3680(g)) (g) Payments for courses which are repeated. VA may pay subsistence allowance to a veteran who repeats a course under conditions described in § 21.132. (Authority: 38 U.S.C. 3680(a))...

  7. 30 CFR 206.157 - Determination of transportation allowances.

    Science.gov (United States)

    2010-07-01

    ... industry and gas customers. GRI fees are allowable provided such fees are mandatory in FERC-approved... or off the lease, for more than 30 days; (2) Aggregator/marketer fees. This includes fees you pay to... arrange marketing or transportation, if such fees are separately identified from aggregator/marketer...

  8. 30 CFR 206.159 - Determination of processing allowances.

    Science.gov (United States)

    2010-07-01

    ... depreciation, the lessee may elect to use either a straight-line depreciation method based on the life of..., including operating and maintenance expenses, overhead, and either depreciation and a return on..., including royalties, are not allowable expenses. (iv) A lessee may use either depreciation or a return...

  9. Video Allows Young Scientists New Ways to Be Seen

    Science.gov (United States)

    Park, John C.

    2009-01-01

    Science is frequently a visual endeavor, dependent on direct or indirect observations. Teachers have long employed motion pictures in the science classroom to allow students to make indirect observations, but the capabilities of digital video offer opportunities to engage students in active science learning. Not only can watching a digital video…

  10. Mitigation of Global Warming with Focus on Personal Carbon Allowances

    DEFF Research Database (Denmark)

    Meyer, Niels I

    2008-01-01

    The mitigation of global warming requires new efficient systems and methods. The paper presents a new proposal called personal carbon allowances with caps on the CO2 emission from household heating and electricity and on emission from transport in private cars and in personal air flights. Results...

  11. 32 CFR 584.7 - Basic allowance for quarters.

    Science.gov (United States)

    2010-07-01

    ... CUSTODY, AND PATERNITY § 584.7 Basic allowance for quarters. (a) Eligibility. (1) Soldiers entitled to...-dependents rate each month in support of their families. (See DODPM, part 3.) This is so even if a divorce... spouse or stepchildren after the divorce. BAQ at the “with dependents” rate is not authorized when...

  12. 38 CFR 38.629 - Outer Burial Receptacle Allowance.

    Science.gov (United States)

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Outer Burial Receptacle... (CONTINUED) NATIONAL CEMETERIES OF THE DEPARTMENT OF VETERANS AFFAIRS § 38.629 Outer Burial Receptacle Allowance. (a) Definitions—Outer burial receptacle. For purposes of this section, an outer burial...

  13. 大规模风电高压脱网分析及协调预防控制策略%Outage Analysis of Large Scale Wind Power Under High Voltage Condition and Coordinated Prevention and Control Strategy

    Institute of Scientific and Technical Information of China (English)

    赵宏博; 姚良忠; 王伟胜; 张文亮; 迟永宁; 李琰

    2015-01-01

    由于受扰系统在故障切除后恢复过程中出现高电压引起风电机组大规模脱网的事故近年来频发,因此基于近年来已发生的大规模风电机群脱网事故,从风电机组故障穿越期间动态无功控制策略和风电场附加无功补偿装置控制特性两个方面分析了受扰后电网发生高电压现象的主要原因,并通过现场测试验证了机组动态无功控制策略对机端电压的影响。在此基础上,提出了避免风电机组高电压脱网的协调预防控制策略,即风电机组在满足高电压穿越要求的前提下根据电压变化参与系统无功调节,风电场附加无功补偿装置根据并网点电压以及场内机组脱网情况实现快速调节和退出。最后,通过仿真验证了协调预防控制策略的有效性。%Based on recent years”frequent outage of large scale wind power by high voltage during voltage recovery period after grid fault,the high voltage phenomena after grid fault is analyzed from two aspects,one is the dynamic reactive power control strategy during low voltage ride through (LVRT) of wind turbines,the other is control characteristics of reactive power compensation devices in wind farms.It is verified by field test data on wind turbines that the dynamic voltage control strategy could affect terminal voltage of wind turbines.Based on the analysis,this paper presents a coordinated prevention and control strategy to avoid outage of large scale wind power resulting from high voltage.The wind turbines which fulfill the high voltage ride through(HVRT) requirements would regulate the reactive power of power system according to the fluctuation of wind turbine terminal voltage.The reactive power compensation devices in wind farms would realize fast regulation and outage according to the fluctuation of system voltage and the outage saturation of wind turbines in wind farms. Finally, the coordinated prevention and control strategy is validated

  14. 核电机组停运对南方电网运行影响研究%Study on the Impact of Nuclear Power Plant Outage on the CSG Operation

    Institute of Scientific and Technical Information of China (English)

    周保荣; 柳勇军; 陈建斌; 姚文峰; 涂亮; 蒙文川

    2011-01-01

    Introducing the impacts of Japan "3.11" earthquake on the power supply of Tokyo Electric Power Company, this paper analyzes the possible operation situations of China Southern Power Grid (CSG) as the nuclear power plants in the CSG area being in outage. The results are as follows: If the nuclear power units in Dayawan and Lingao being in outage in 2011, it will happen that Guangdong Power Grid will be in low frequency load shedding as CSG being in valley load period, and some parts of Guangxi Power Grid will be in low voltage load shedding with power cut in Shenzhen district as CSG being in peak load period. If the nuclear power units in Yangjiang, Taishan and Fangchenggang being in outage in 201S, this will not lead the nearby networks being in opwer cut and low frequency load shedding and low voltage load shedding of CSG If the nuclear power units in Changjiang being in outage in 2016, this will not lead Hainan Power Grid being in low frequency load shedding as the grid being in interconnection with Guangdong Power Grid by one/two 500 kV tie lines.%介绍了日本“3·11”大地震对东京电力公司供电的影响,分析了若南方电网区域内核电机组停运,南方电网运行的情况将会如何。结果显示:2011年若大亚湾、岭澳核电机组停运,当南方电网以小方式运行时可能造成广东电网低周减载动作;当南方电网以大方式运行时可能引起广西部分地区低压减栽装置动作,且事故后深圳地区负荷可能受限。2015年阳江核电、台山核电和防城港核电机组分别停运,不会造成其近区电网供电受限,也不会引起系统低周减载或低压减载动作。2016年若海南昌江核电机组停运,当海南电网与广东电网通过2回或1回500kV交流联络线保持联网时,海南电网低周减栽不会动作。

  15. 基于网络编码的双向多中继系统中断概率分析%Outage Probability Analysis of Bi-directional Multi-Relay System Based on Network Coding

    Institute of Scientific and Technical Information of China (English)

    梁文文; 徐友云; 田华; 许魁

    2012-01-01

    Network Coding has been investigated extensively in bi-directional multi-relay system and can improve the throughput of bi-directional multi-relay system effectually. Firstly two outage probability expressions of bi-directional multi-relay system on independent orthogonal channel and multiple access channel with decode-and-forward based on network coding are given in this paper and theory analysis is proved correct by Monte Carlo simulation. Secondly we analyze the system average outage performance at different situation of different power allocation coefficient, SNR and the number of relay, indicating the inherent relationship between power allocation coefficient and total system power as well as the number of relay. Simulation results indicate that optimal system outage performances of bi-directional multi-relay system on the two channels are attained when power allocation coefficient is chosen in[0.5,0.6] , and we can see that outage performance of the system on multiple access channel is better than the independent orthogonal channel.%网络编码在双向多中继系统中已经得到了广泛地研究,并有效地提高了双向多中继系统的吞吐量.首先本文导出了在译码转发方式时,独立正交信道和多接入信道下基于网络编码的双向多中继系统平均中断概率表达式.Monte Carlo仿真和理论分析非常吻合,验证了理论分析的正确性.之后分析了系统平均中断性能在不同信噪比和不同中继节点个数等多种情形下与功率分配因子的关系,揭示了功率分配因子与系统总功率和中继节点数量之间的内在关系.仿真结果表明,双向多中继系统采用网络编码进行传输时,在独立正交信道下和多接入信道下的功率分配因子取值在区间[0.5,0.6]内能够获得最优的系统中断概率性能,并且多接入信道下的系统中断性能要好于独立正交信道.

  16. 基于中断概率的协作通信中继选择与功率分配算法%Outage probability based power allocation and relay selection algorithm in cooperative communication

    Institute of Scientific and Technical Information of China (English)

    孙立悦; 赵晓晖; 虢明

    2013-01-01

    The relay selection and power optimization of multi-relay cooperative communication network under a joint sum power constraint was considered. A low complexity relay selection and power allocation algorithm was also pro-posed in amplify-and-forward cooperative network aiming at minimizing the probability of system outage. In this scheme, optimal power allocation among source and relay nodes was conducted. According to the SNR, an optimal relay node set was selected and a power allocation factor leading to a lower system outage probability was obtained by steepest descent method. This algorithm did not need large quantity of channel statistical information and equal power condition. It can obtain the best set of relay nodes under optimal power allocation only by solving the arranged matrix on the basis of Sig-nal to Noise Ratio. Simulation results show that the proposed relay selection and power allocation algorithm, under the same conditions, compared in the outage probability in different relay node set among several algorithms, achieves better performance in outage probability and power efficiency.%研究了功率受限情况下多中继协作通信网络的中继选择和功率优化问题。在AF网络中,提出了一种低复杂度中继选择与功率分配算法,其目标是在总功率一定的条件下使系统的中断概率最小。本算法对源节点和所有潜在中继节点进行功率分配,结合当前信噪比选择最优的中继集合,通过最速下降法求出使系统中断概率最低的功率分配因子。该算法不需要知道大量瞬时信道信息、不需要系统在等功率条件下进行中继选择,只需求得中继节点排列矩阵便可根据当前信噪比自适应获得最优中继节点集合。仿真结果表明,在相同条件下,该算法明显优于不同中继节点集合下几种算法的中断性能,并且与传统的SAF及AAF算法相比,有效降低了中断概率,提升了系统性能和功率效率。

  17. 变电站大型作业停电方式安全效果分析%Safety Effect Analysis of Substation Power Outage Way for Large Work

    Institute of Scientific and Technical Information of China (English)

    马文波; 张健; 刘剑

    2012-01-01

    The paper introduces the related concepts, structure and characteristics and launch method of large work of electric power enterprise, through comparison and analysis of different power outage ways for all equipment and part of equipment, get the overhauling work of 1 l0kV substation under power cuts is more secure, and easier.%介绍了电力企业大型作业的相关概念、组织架构和特点以及开展的方法,通过对变电站全部设备停电和部分设备停电作业方式的对比、分析,得出了110kV变电站全部停电方式下检修作业的效果更安全、更轻松.

  18. An Improved Algorithm for Reliability Assessment of Distribution Network Considering Complex Load Transfer and Scheduled Outage%考虑复杂转供和预安排停电的配电网可靠性评估

    Institute of Scientific and Technical Information of China (English)

    邱生敏; 王浩浩; 管霖

    2011-01-01

    A method to simplify distribution network and classify nodes is proposed to reduce calculation burden.Considering capacity constraint, the method to judge whether power load can be transferred via tie-line after the fault is researched and a method to calculate the reliability index based on the judgment of transferring is proposed. The influence of scheduled outage on reliability of distribution network is analyzed and a method to calculate the reliability index of distribution network under scheduled outage is given. The total reliability index of distribution network is the very summation of above-mentioned two calculated reliability indices. Results of calculation example show that the proposed method is feasible.%为减少计算量,提出了配电网网络简化及节点分类方法.在考虑容量约束的情况下,分析了故障后判断负荷能否通过联络线实现转供的方法,提出了基于转供判断的配电网可靠性指标计算方法.分析了预安排停电对配电网可靠性的影响,提出了预安排停电情况下的配电网可靠性指标计算方法.将以上2部分可靠性指标相加可得配电网总的可靠性指标.算例结果验证了该方法的可行性.

  19. Radiative data for allowed transitions in Ni XXV

    Energy Technology Data Exchange (ETDEWEB)

    Tully, John A [Departement Cassiopee, Observatoire de la Cote d' Azur, BP 4229, 06304 Nice Cedex 4 (France); Chidichimo, Marita C [Department of Applied Mathematics, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada)

    2004-02-14

    Using Hibbert's configuration interaction program CIV3, which allows for relativistic effects by means of the Breit-Pauli approximation, we have computed radiative data for the 272 optically allowed transitions between levels i = 2l{sub 1} 2l{sub 2} S'L'J' and j = 2l{sub 3} n{sub 4}l{sub 4} SLJ with n{sub 4} = 2, 3, 4 in Be-like Ni XXV. Oscillator strengths f, transition probabilities A, line wavelengths {lambda} and energies E{sub ij} in cm{sup -1} are tabulated. We make detailed comparisons with related work done by other authors during the period 1977 to 2000.

  20. Just do it: action-dependent learning allows sensory prediction.

    Directory of Open Access Journals (Sweden)

    Itai Novick

    Full Text Available Sensory-motor learning is commonly considered as a mapping process, whereby sensory information is transformed into the motor commands that drive actions. However, this directional mapping, from inputs to outputs, is part of a loop; sensory stimuli cause actions and vice versa. Here, we explore whether actions affect the understanding of the sensory input that they cause. Using a visuo-motor task in humans, we demonstrate two types of learning-related behavioral effects. Stimulus-dependent effects reflect stimulus-response learning, while action-dependent effects reflect a distinct learning component, allowing the brain to predict the forthcoming sensory outcome of actions. Together, the stimulus-dependent and the action-dependent learning components allow the brain to construct a complete internal representation of the sensory-motor loop.

  1. Near Real-Time Applications of Earth Remote Sensing for Response to Meteorological Disasters

    Science.gov (United States)

    Molthan, Andrew L.; Burks, Jason E.; McGrath, Kevin M.; Bell, Jordan R.

    2013-01-01

    Numerous on-orbit satellites provide a wide range of spatial, spectral, and temporal resolutions supporting the use of their resulting imagery in assessments of disasters that are meteorological in nature. This presentation will provide an overview of recent use of Earth remote sensing by NASA's Short-term Prediction Research and Transition (SPoRT) Center in response to disaster activities in 2012 and 2013, along with case studies supporting ongoing research and development. The SPoRT Center, with support from NASA's Applied Sciences Program, has explored a variety of new applications of Earth-observing sensors to support disaster response. In May 2013, the SPoRT Center developed unique power outage composites representing the first clear sky view of damage inflicted upon Moore and Oklahoma City, Oklahoma following the devastating EF-5 tornado that occurred on May 20. Subsequent ASTER, MODIS, Landsat-7 and Landsat-8 imagery help to identify the damaged area. Higher resolution imagery of Moore, Oklahoma were provided by commercial satellites and the recently available International Space Station (ISS) SERVIR Environmental Research and Visualization System (ISERV) instrument. New techniques are being explored by the SPoRT team in order to better identify damage visible in high resolution imagery, and to monitor ongoing recovery for Moore, Oklahoma. Other applications are being developed to refine light source detections with the VIIRS day-night band and to map hail during the growing season through combination of available satellite and radar imagery. The aforementioned products and support are not useful unless they are distributed in a timely manner and within an appropriate decision support system. This presentation will provide an update on ongoing activities to support inclusion of these data sets within the NOAA National Weather Service Damage Assessment Toolkit, which allows meteorologists in the field to consult available satellite imagery while performing

  2. Mass spectrometry allows direct identification of proteins in large genomes

    DEFF Research Database (Denmark)

    Küster, B; Mortensen, Peter V.; Andersen, Jens S.

    2001-01-01

    Proteome projects seek to provide systematic functional analysis of the genes uncovered by genome sequencing initiatives. Mass spectrometric protein identification is a key requirement in these studies but to date, database searching tools rely on the availability of protein sequences derived fro...... genome and allows identification, mapping, cloning and assistance in gene prediction of any protein for which minimal mass spectrometric information can be obtained. Several novel proteins from Arabidopsis thaliana and human have been discovered in this way....

  3. Scientific substantination of maximum allowable concentration of fluopicolide in water

    Directory of Open Access Journals (Sweden)

    Pelo I.М.

    2014-03-01

    Full Text Available In order to substantiate fluopicolide maximum allowable concentration in the water of water reservoirs the research was carried out. Methods of study: laboratory hygienic experiment using organoleptic and sanitary-chemical, sanitary-toxicological, sanitary-microbiological and mathematical methods. The results of fluopicolide influence on organoleptic properties of water, sanitary regimen of reservoirs for household purposes were given and its subthreshold concentration in water by sanitary and toxicological hazard index was calculated. The threshold concentration of the substance by the main hazard criteria was established, the maximum allowable concentration in water was substantiated. The studies led to the following conclusions: fluopicolide threshold concentration in water by organoleptic hazard index (limiting criterion – the smell – 0.15 mg/dm3, general sanitary hazard index (limiting criteria – impact on the number of saprophytic microflora, biochemical oxygen demand and nitrification – 0.015 mg/dm3, the maximum noneffective concentration – 0.14 mg/dm3, the maximum allowable concentration - 0.015 mg/dm3.

  4. Funding child rearing: child allowance and parental leave.

    Science.gov (United States)

    Walker, J R

    1996-01-01

    This article proposes two financing plans to address what the author identifies as the two primary concerns in the child care field: (1) a child allowance for poor and near-poor households to address the child care problems of low-income families, and (2) a program of voluntary parental leave, available to all parents at child birth or adoption, to ensure the adequacy of infant care. The child allowance plan would cover the first three children in families up to 175% of the poverty level (more than 22 million children) at an annual cost of $45 billion. The author suggests that the allowance could be financed by redirecting funds from existing income support (for example, Aid to Families with Dependent Children), tax credit, and tax deduction programs. Financing the parental leave program would require new revenues, generated by an employee-paid increase in payroll tax totaling 3.5%. Each employee's contributions would create a parental leave account (PLA). Families could use the funds in these accounts to cover the cost of a one-year leave from work after the birth or adoption of a child. If families did not have enough dollars in their accounts to cover the cost of the leave, the federal government would extend a low-interest loan to them, which they would have to pay back. The amount individuals receive through Social Security would be adjusted upward or downward according to the balances in their parental leave accounts at retirement. The author suggests that both proposals would help parents balance work and family obligations and protect parental freedom of choice over the care and upbringing of their children.

  5. Bends in nanotubes allow electric spin control and coupling

    DEFF Research Database (Denmark)

    Flensberg, Karsten; Marcus, Charles Masamed

    2010-01-01

    We investigate combined effects of spin-orbit coupling and magnetic field in carbon nanotubes containing one or more bends along their length. We show how bends can be used to provide electrical control of confined spins, while spins confined in straight segments remain insensitive to electric...... fields. Device geometries that allow general rotation of single spins are presented and analyzed. In addition, capacitive coupling along bends provides coherent spin-spin interaction, including between otherwise disconnected nanotubes, completing a universal set of one- and two-qubit gates....

  6. Allowable levels of take for the trade in Nearctic songbirds

    Science.gov (United States)

    Johnson, Fred A.; Walters, Matthew A.H.; Boomer, G. Scott

    2012-01-01

    The take of Nearctic songbirds for the caged-bird trade is an important cultural and economic activity in Mexico, but its sustainability has been questioned. We relied on the theta-logistic population model to explore options for setting allowable levels of take for 11 species of passerines that were subject to legal take in Mexico in 2010. Because estimates of population size necessary for making periodic adjustments to levels of take are not routinely available, we examined the conditions under which a constant level of take might contribute to population depletion (i.e., a population below its level of maximum net productivity). The chance of depleting a population is highest when levels of take are based on population sizes that happen to be much lower or higher than the level of maximum net productivity, when environmental variation is relatively high and serially correlated, and when the interval between estimation of population size is relatively long (≥5 years). To estimate demographic rates of songbirds involved in the Mexican trade we relied on published information and allometric relationships to develop probability distributions for key rates, and then sampled from those distributions to characterize the uncertainty in potential levels of take. Estimates of the intrinsic rate of growth (r) were highly variable, but median estimates were consistent with those expected for relatively short-lived, highly fecund species. Allowing for the possibility of nonlinear density dependence generally resulted in allowable levels of take that were lower than would have been the case under an assumption of linearity. Levels of take authorized by the Mexican government in 2010 for the 11 species we examined were small in comparison to relatively conservative allowable levels of take (i.e., those intended to achieve 50% of maximum sustainable yield). However, the actual levels of take in Mexico are unknown and almost certainly exceed the authorized take. Also, the take

  7. Allowable carbon emissions for medium-to-high mitigation scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Tachiiri, Kaoru; Hargreaves, Julia C.; Annan, James D.; Kawamiya, Michio [Research Inst. for Global Change, Japan Agency for Marine-Earth Science and Technology, Yokohama, (Japan)], e-mail: tachiiri@jamstec.go.jp; Huntingford, Chris [Centre for Ecology and Hydrology, Wallingford (United Kingdom)

    2013-11-15

    Using an ensemble of simulations with an intermediate complexity climate model and in a probabilistic framework, we estimate future ranges of carbon dioxide (CO{sub 2}) emissions in order to follow three medium-high mitigation concentration pathways: RCP2.6, RCP4.5 and SCP4.5 to 2.6. Uncertainty is first estimated by allowing modelled equilibrium climate sensitivity, aerosol forcing and intrinsic physical and biogeochemical processes to vary within widely accepted ranges. Results are then constrained by comparison against contemporary measurements. For both constrained and unconstrained projections, our calculated allowable emissions are close to the standard (harmonised) emission scenarios associated with these pathways. For RCP4.5, which is the most moderate scenario considered in terms of required emission abatement, then after year 2100 very low net emissions are needed to maintain prescribed year 2100 CO{sub 2} concentrations. As expected, RCP2.6 and SCP4.5 to 2.6 require more strict emission reductions. The implication of this is that direct sequestration of carbon dioxide is likely to be required for RCP4.5 or higher mitigation scenarios, to offset any minimum emissions for society to function (the 'emissions floor'). Despite large uncertainties in the physical and biogeochemical processes, constraints from model-observational comparisons support a high degree of confidence in predicting the allowable emissions consistent with a particular concentration pathway. In contrast the uncertainty in the resulting temperature range remains large. For many parameter sets, and especially for RCP2.6, the land will turn into a carbon source within the twenty first century, but the ocean will remain as a carbon sink. For land carbon storage and our modelling framework, major reductions are seen in northern high latitudes and the Amazon basin even after atmospheric CO{sub 2} is stabilised, while for ocean carbon uptake, the tropical ocean regions will be a

  8. Maximum Allowable Dynamic Load of Mobile Manipulators with Stability Consideration

    Directory of Open Access Journals (Sweden)

    Heidary H. R.

    2015-09-01

    Full Text Available High payload to mass ratio is one of the advantages of mobile robot manipulators. In this paper, a general formula for finding the maximum allowable dynamic load (MADL of wheeled mobile robot is presented. Mobile manipulators operating in field environments will be required to manipulate large loads, and to perform such tasks on uneven terrain, which may cause the system to reach dangerous tip-over instability. Therefore, the method is expanded for finding the MADL of mobile manipulators with stability consideration. Moment-Height Stability (MHS criterion is used as an index for the system stability. Full dynamic model of wheeled mobile base and mounted manipulator is considered with respect to the dynamic of non-holonomic constraint. Then, a method for determination of the maximum allowable loads is described, subject to actuator constraints and by imposing the stability limitation as a new constraint. The actuator torque constraint is applied by using a speed-torque characteristics curve of a typical DC motor. In order to verify the effectiveness of the presented algorithm, several simulation studies considering a two-link planar manipulator, mounted on a mobile base are presented and the results are discussed.

  9. Study on the historical outage data based probability distribution of cascading line failures in a regional power grid%基于历史故障记录数据的电网连锁故障规模概率分布研究

    Institute of Scientific and Technical Information of China (English)

    任惠; 熊吉; David Watts; 陈曦

    2014-01-01

    The probabilistic distribution of cascading outages is one of the main measures to describe the propagation of cascading outages, and to evaluate the risk of the large scale outages of the power system. Historical outage data has always been used for power system reliability evaluation, and by combined with the branching process model, it is used for cascading outage analysis for a regional power grid. Based on the 14-year utility historical outage data from a regional power grid in China, several known probabilistic models are tested and compared, and a Borel-Tanner branching process model is proposed to estimate the probabilities of cascading line outages. Statistical error analysis is performed to study the effectiveness of applying the Borel-Tanner model to practical grid risk management. Results indicate that the empirical distribution of the total number of line outages is approximated well by the Borel-Tanner model. For the same confidential level, the estimation of the probability distribution of the larger cascades by the Borel-Tanner branching process model requires significantly fewer recorded outage data than empirical estimation by a factor of 10-1.%连锁故障规模的概率分布描述了电网连锁故障的传播特点,是衡量电网发生大规模停电故障概率的有效方法之一。针对历史故障统计数据进行计算,是传统电力系统可靠性评估方法之一。将其与分支过程模型结合,用于区域电网的连锁故障分析。采用某区域电网14年历史故障数据为样本数据,针对多种概率模型进行比较分析,提出采用波雷-坦尔分支过程模型计算该区域电网连锁故障规模的概率分布,并采用误差分析研究了波雷-坦尔模型应用于实际电网风险管理的有效性和可能性。结果表明,波雷-坦尔模型能够很好地估计线路故障规模的概率分布。在相同置信度要求下,基于波雷-坦尔模型估计故障概率分布所需

  10. 广东电网同塔多回线路雷击跳闸影响因素及故障分析%Influencing Factors of Lightning Outage in Multi-Circuit Transmission Lines on Same Tower in Guangdong Power Grid and Fault Analysis

    Institute of Scientific and Technical Information of China (English)

    彭向阳; 詹清华; 周华敏

    2012-01-01

    In recent years the land supply for power construction projects is decreased increasingly and it makes the planner of UHV/EHV transmission line construction inclined to adopt the structure of multi-circuit transmission lines on the same tower, therefore as the result the proportion of simultaneous lightning outage of multi-circuit transmission lines on the same tower evidently raises, thus the secure operation of power grid is affected. The peculiarity of simultaneous lightning outage occurred in multi-circuit transmission lines on the same tower is presented and the influences of key factors on lightning outage are analyzed, besides, the recovery analysis on electromagnetic transient of typical simultaneous lightning outage fault is performed. Results of recovery analysis show that the main reason leading to simultaneous lightning outage of multi-circuit transmission lines on the same tower is the flashback of lightning, however successive shielding failures lead to simultaneous lightning outage of multi-circuit transmission lines as well. It is emphasized that special attentions should be paid to the prevention of simultaneous lightning outage occurred in 110 kV and 220 kV double circuit transmission lines on the same tower, and it is pointed out that the power frequency voltage and the phase sequence arrangement of transmission lines on the same tower greatly influence the lightning outage caused by flashback; the simultaneous lightning outages often occur in the same phase of multi-circuit transmission lines; and the flashover is prone to occur on the upper cross arm insulator that is closer to the struck point.%近年来广东地区线路工程用地趋紧,同塔多回线路规模迅速增大,导致多回线路雷击同时跳闸比例显著上升,给电网安全运行带来新的挑战。介绍同塔线路雷击同时跳闸的特点,分析雷击跳闸关键因素的影响,并对典型雷击同时跳闸故障进行电磁暂态复原分析。指出雷

  11. Performance and goats behavior in pasture of Andropogon grass under different forage allowances

    Directory of Open Access Journals (Sweden)

    Daniel Louçana da Costa Araújo

    2015-07-01

    Full Text Available This study was accomplished to evaluate the behavior and performance of goats in to grazing on grass Andropogon gayanus Kunth var. Bisquamulatus (Hochst Hack. cv. Planaltina submitted to three forage allowances: 11, 15 and 19% BW/day, under continuous grazing. The experimental design to assess the grazing behaviour was randomized blocks in a split-plot with five replicates within the block. In the plots, we evaluated the effect of forage allowances and in the subplots, the months May and June. While for evaluation of animal performance was in complete block design with five replicates within the block. The different forage allowance did not cause structural changes in the pasture, except in height. However, there was an increase of dead material, leaf/stem ratio and reducing of height during the grazing period. The behavioral variables were not affected by forage allowance, except for the time of displacement, whereby goats spent more time in pastures with offer of 11% BW. The goats remained most part of the time in grazing and idle, corresponding to 89% and 5% of the evaluation time, respectively. Higher bit rate was observed in June, among the offerings, and 15 and 19% BW. The ingestive and grazing behaviour in goats is changed by the accumulation of dead material and stem in pasture from Andropogon grass during at rainy season. The forage supply 11% of BW increases the time of displacement of goats grazing on Andropogon grass. The management of grazing Andropogon grass with forage allowance being 11 and 19% of BW provides low weight gains in goats during the rainy season.

  12. Should Internet Jargon Be Allowed in College Entrance Examinations?

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Anyone who has chatted online knows that when the heat is on, brief is best. There is just no time to type out correctly spelled, grammatically gleaming sentenceswhen the gossip gallops across the keyboard. Symbols, jargon, abbreviations, similaritie

  13. Allowances for evolving coastal flood risk under uncertain local sea-level rise

    Science.gov (United States)

    Buchanan, M. K.; Kopp, R. E.; Oppenheimer, M.; Tebaldi, C.

    2015-12-01

    Sea-level rise (SLR) causes estimates of flood risk made under the assumption of stationary mean sea level to be biased low. However, adjustments to flood return levels made assuming fixed increases of sea level are also inaccurate when applied to sea level that is rising over time at an uncertain rate. To accommodate both the temporal dynamics of SLR and their uncertainty, we develop an Average Annual Design Life Level (AADLL) metric and associated SLR allowances [1,2]. The AADLL is the flood level corresponding to a time-integrated annual expected probability of occurrence (AEP) under uncertainty over the lifetime of an asset; AADLL allowances are the adjustment from 2000 levels that maintain current risk. Given non-stationary and uncertain SLR, AADLL flood levels and allowances provide estimates of flood protection heights and offsets for different planning horizons and different levels of confidence in SLR projections in coastal areas. Allowances are a function primarily of local SLR and are nearly independent of AEP. Here we employ probabilistic SLR projections [3] to illustrate the calculation of AADLL flood levels and allowances with a representative set of long-duration tide gauges along U.S. coastlines. [1] Rootzen et al., 2014, Water Resources Research 49: 5964-5972. [2] Hunter, 2013, Ocean Engineering 71: 17-27. [3] Kopp et al., 2014, Earth's Future 2: 383-406.

  14. Robust reliable H∞ control for discrete-time Markov jump linear systems with actuator failures

    Institute of Scientific and Technical Information of China (English)

    Chen Jiaorong; Liu Fei

    2008-01-01

    The robust reliable H∞ control problem for discrete-time Markovian jump systems with actuator failures is studied.A more practical model of actuator failures than outage is considered.Based on the state feedback method,the resulting closed-loop systems are reliable in that they remain robust stochastically stable and satisfy a certain level of Hex disturbance attenuation not only when all actuators are operational,but also in case of some actuator failures.The solvability condition of controllers can be equivalent to a feasibility problem of coupled linear matrix inequalities (LMIs).A numerical example is also given to illustrate the design procedures and their effectiveness.

  15. Chromosome duplication in Brachiaria (A. Rich. Stapf allows intraspecific crosses

    Directory of Open Access Journals (Sweden)

    Carine Simioni

    2009-01-01

    Full Text Available Brachiaria decumbens cv. Basilisk is the single most important forage grass used for pastures in the tropics.Breeding to produce improved cultivars has been impossible until now due to the lack of compatible sexual ecotypes. Thispaper reports the success of somatic chromosome duplication of sexually reproducing diploid plants of B. decumbens and ofa diploid hybrid between B. decumbens and B. brizantha, which should allow intraspecific crosses with natural apomictictetraploid accessions of either species. Polyploidization was induced in explants cultured in vitro on a medium supplementedwith colchicine at 0.01% for 48 hours, transferred to the same medium without colchicine until shoot regeneration occurred.Five sexual tetraploid plants (3.9% of plants recovered were obtained. Crosses with apomictic cultivars recovered 14 seeds.The novel sexual tetraploids generated were unique and represented a major breakthrough in breeding B. decumbens toobtain superior hybrids.

  16. Super-allowed Fermi beta-decay revisited

    CERN Document Server

    Wilkinson, D H

    2002-01-01

    Analysis of J suppi=0 sup +->0 sup + super-allowed Fermi transitions is limited with respect to the precision of its outcome in terms of the Fermi coupling constant neither by the accuracy of the experimental input data nor by the confidence with which the radiative corrections can be applied but rather by knowledge of the nuclear mismatch: the subversion of isospin symmetry along the multiplets. Theoretical estimates of this mismatch differ considerably from to their direct nuclide-by-nuclide application results in an apparent clear violation of the hypothesis of conservation of the vector current and evident inconsistency with unitary of the Cabibbo-Kobayashi-Maskawa matrix. This paper pursues and elaborates the earlier suggestion that, in these unsatisfactory circumstances, the best procedure is to look to the experimental data themselves to determine and eliminate the mismatch by appropriate extrapolation to Z approx 0 where the mismatch falls away. This is done: (i) without any prior correction for misma...

  17. Short peptides allowing preferential detection of Candida albicans hyphae.

    Science.gov (United States)

    Kaba, Hani E J; Pölderl, Antonia; Bilitewski, Ursula

    2015-09-01

    Whereas the detection of pathogens via recognition of surface structures by specific antibodies and various types of antibody mimics is frequently described, the applicability of short linear peptides as sensor molecules or diagnostic tools is less well-known. We selected peptides which were previously reported to bind to recombinant S. cerevisiae cells, expressing members of the C. albicans Agglutinin-Like-Sequence (ALS) cell wall protein family. We slightly modified amino acid sequences to evaluate peptide sequence properties influencing binding to C. albicans cells. Among the selected peptides, decamer peptides with an "AP"-N-terminus were superior to shorter peptides. The new decamer peptide FBP4 stained viable C. albicans cells more efficiently in their mature hyphal form than in their yeast form. Moreover, it allowed distinction of C. albicans from other related Candida spp. and could thus be the basis for the development of a useful tool for the diagnosis of invasive candidiasis.

  18. Allowing for heterogeneity in monetary subjective well-being valuations.

    Science.gov (United States)

    Mentzakis, Emmanouil

    2011-03-01

    Recent research on 'happiness' regression equations has shown how monetary values can be put on the well-being effects of many life events (like health problems, marriage or the death of a spouse). Potentially, such work has practical implications for policy-makers and the courts. However, this article argues that we need to be careful in such work to use the appropriate statistical method. It goes beyond previous research and allows for heterogeneity in the subjective well-being scales. Using less restrictive models than the current literature, the article argues that standard linear or ordered response models seem consistently to overstate valuations. With data from the UK, it provides new monetary estimates of the well-being consequences of a number of health problems, social capital indicators, marital status changes and social relationships.

  19. Utility regulators and the market for emission allowances

    Energy Technology Data Exchange (ETDEWEB)

    Bohi, D.R.

    1993-07-01

    When it comes to emission trading under the Clean Air Act, a major concern of most people in the electric utilities industry is the effect of this new form of environmental regulation on the industry and the way it is regulated. This paper focuses on a different concern: the effect of the industry and the way it is regulated on the emission trading program. Emission trading must prove to be successful in lowering the cost of reducing sulfur dioxide emissions if this approach to environmental regulation is to be regarded as a viable substitute for traditional command-and-control regulation. In addition, whether or not utilities will buy and sell allowances as intended depends on the actions of the public utility regulators. This paper covers both setting the cost recovery rules and the incentive to sell and the capital gain.

  20. Radical reconciliation: The TRC should have allowed Zacchaeus to testify?

    Directory of Open Access Journals (Sweden)

    Tshepo Lephakga

    2016-02-01

    Full Text Available This article seeks to point out that, the inclusion of a theological term – that is ‘reconciliation’ (at the request of F.W. de Klerk on behalf of the National Party to what was supposed to be the ‘Truth Commission’ (Boesak & DeYoung 2012; Stevens Franchi & Swart 2006 – was for the purpose of taming the work of this commission and using reconciliation to merely reach some political accommodation which did not address the critical questions of justice, equality, and dignity which are prominent in the biblical understanding of reconciliation (Boesak 2008; Boesak & DeYoung 2012:1; Lephakga 2015; Terreblanche 2002. However, it is important to point out that, the problem was not the theological word – that is ‘reconciliation’– but the understanding and interpretation of it in South Africa. This is because previously in South Africa the Bible was made a servant to ideology (Lephakga 2012, 2013; Moodie 1975; Serfontein 1982 and thus domesticated for the purposes of subjection and control (Boesak & DeYoung 2012. As such, this article contends that, the call for the inclusion of ‘reconciliation’ within the ‘truth commission’ was not to allow reconciliation to confront the country with the demands of the gospel but to blunt the process of radical change (Boesak & DeYoung 2012. Therefore, this article will point out that the shortcomings of the South African Truth and Reconciliation Commission (TRC need to be understood against the following events which occurred between the period 1989 to 1995: (1 the fall of the Soviet Union (Cronin 1994:2–6; (2 the National Party’s (NP and South African business sector’s interest in negotiations with the African National Congress (ANC (Cronin 1994:2–6; Mkhondo 1993:3–43; Terreblanche 2002:51–124; (3 the elite compromise (Terreblanche 2002:51–124; and the sudden passing of the Promotion of National Unity and Reconciliation Act, no 34 of 1995 (TRC, Vol. 1998. This paper will use