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Sample records for building outage frp

  1. 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 , ...

  2. CONTRIBUTION TO THE POTENTIAL OF USING FRP MATERIALS IN THE REHABILITATION AND STABILIZATION OF TIMBERED BUILDINGS

    Directory of Open Access Journals (Sweden)

    Tomáš Čejka

    2015-12-01

    Full Text Available Wooden log, timbered perimeter and interior walls ranked among the most common building constructions used from the Early Middle Ages. In most cases, the local natural resources, i.e. wood, clay, straw and stone, were used for building houses with wooden framing. This article outlines typical defects and failures of timbered houses, “classic” techniques for the rehabilitation of these defects and failures indicating the potential of using composite materials based on high- strength fibres and epoxy resin in the rehabilitation and strengthening of timbered buildings.

  3. Facility Response Plan (FRP)

    Data.gov (United States)

    U.S. Environmental Protection Agency — A Facility Response Plan (FRP) demonstrates a facility's preparedness to respond to a worst case oil discharge. Under the Clean Water Act, as amended by the Oil...

  4. Architectural engineering of FRP bridges

    OpenAIRE

    Smits, J.E.P.

    2014-01-01

    This paper deals with the use of Fibre Reinforced Polymers (FRP's) in architectural and structural bridge design. The challenges and opportunities that come with this relatively new material are discussed. An inventory is made of recent engineers' solutions in FRP, followed by a discussion on architectural application of FRP's derived from the authors architectural practice.

  5. FRP tendon anchorage in post-tensioned concrete structures

    DEFF Research Database (Denmark)

    Schmidt, Jacob Wittrup; Täljsten, Björn; Bennitz, Anders

    2008-01-01

    Strengthening of building structures by the use of various external post-tensioning steel tendon systems, is known to be a very efficient method. However, FRP as material in external post-tensioning projects has been investigated during the last decade. The advantages for this material are the high...... transfer points. The demand for high capacity anchorage tendons is fulfilled for steel tendons, but no competitive mechanical anchor has yet been developed for FRP tendon. A new small, reliable and more user friendly anchor has to be developed, before FRP tendons can be utilized with all of its capacity....... Thus, several attempts of developing a mechanical FRP anchor have been made worldwide with promising results. Some of these attempts are presented in this paper together with an insight into a present research collaboration project at the Technical University of Denmark, Luleå University of Technology...

  6. Architectural engineering of FRP bridges

    NARCIS (Netherlands)

    Smits, J.E.P.

    2014-01-01

    This paper deals with the use of Fibre Reinforced Polymers (FRP's) in architectural and structural bridge design. The challenges and opportunities that come with this relatively new material are discussed. An inventory is made of recent engineers' solutions in FRP, followed by a discussion on archit

  7. REPAIR AND STRENGTHENING OF REINFORCED CONCRETE BEAMS USING FIBRE REINFORCED POLIMER (FRP MATERIALS

    Directory of Open Access Journals (Sweden)

    Nihat ÇETİNKAYA

    2004-03-01

    Full Text Available The use of Fibre Reinforced Polimer (FRP materials for the repair and strengthening of Reinforced Concrete structures has become widespread recently. FRP materials are being prefered because they have very high tensile strength, resistance to corrosion and they do not affect the use of the building during the repair and strengthening process. Four reinfoced concrete beams repaired and strengthened with FRP materials have been used in this study which were performed at Pamukkale University-Faculty of Engineering- Civil Engineering Department- Structural Engineering Laboratuary. The behaviour of the beams before and after repair and strengthening was compared by obtaining the load- displacement curves under static loading. In this study, it was observed that the repair and strengthening of reinforced concrete beams by using FRP materials had increased the load carrying capacity significantly.

  8. Modular FRP Composite Bridge Deck

    OpenAIRE

    ECT Team, Purdue

    2007-01-01

    The bridge infrastructure of the United States is in constant need of repair and rehabilitation. It is reported that 43% of the bridges in the USA have been identified as being structurally deficient or functionally obsolete due to corrosion. SuperdeckTM, a non-corrosive fiber reinforced polymer (FRP) composite bridge deck. The Deck is designed and engineered into a lightweight, strong and rigid structure that will not corrode. The deck sections, composed of hexagon and double-trapezoid profi...

  9. 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.

  10. Validation of FRP Matting Requirements

    Science.gov (United States)

    2016-08-01

    good. Find out more at www.erdc.usace.army.mil. To search for other technical reports published by ERDC, visit the ERDC online library at http...qt capacity 4 7 Empty Buckets, 5-gal capacity 4 8 Shop towels to wipe rapid set off bolts (rolls/packs) 3 Table 4. FRP Installation Tool Package...dowels 3/8-in.-diam x 4-ft-long tamp rod 10 46 Transmission Funnels 8 47 1.5 gallon shop vacuum 1 ERDC/GSL TR-16-22 12 Table 4. (concluded) 48

  11. Region 9 Facility Response Plan (FRP) - 2014

    Data.gov (United States)

    U.S. Environmental Protection Agency — A Facility Response Plan (FRP) demonstrates a facility's preparedness to respond to a worst case oil discharge. Under the Clean Water Act, as amended by the Oil...

  12. RECENT DEVELOPMENTS IN FRP STRENGTHENING TECHNIQUES

    Institute of Scientific and Technical Information of China (English)

    Zhishen WU(吴智深); Hedong Niu

    2004-01-01

    This paper mainly gives a State-of-the-Art report of recent development in FRP strengthening techniques for structural rehabilitation by starting with a brief review on some achievements in clarifying bonding/debonding mechanisms and developing evaluation/design methodology for predicting debonding failure caused by intermedioate flexural cracks of con crete.Due to some drawbacks of current FRP bonding technique,two effective FRP strengthening methods,i.e.FRP prestressing and hybrid strengthening techniques,are investigated in detail to make full advantage of FRP composite materials.Combining with the newly develiped PBO fiber sheets,a more effective prestressing method is established as compared with carbon fiber sheets,a more effective prestressing method is established as compared with carbon fiber sheets,where several anchorage treatments are also established to prevent anchorage bond failure due to high shear stress concentration after release of prestressed FRP ends.In addition,the fatigue performance of RC beams externally strenghened with prestressed PBO fiber sheets is experimentally studied.For the developments of hybrid composites and their strengthening methods,both experimental and analytical studies are performed to clarify the hybrid strengthening behavior in structures.

  13. FIRE PROTECTION OF TIMBER STRUCTURES STRENGTHENED WITH FRP MATERIALS

    Directory of Open Access Journals (Sweden)

    Radek Zigler

    2015-12-01

    Full Text Available Modern, progressive methods of structures’ strengthening based on the use of composite materials composed of high strength fibers (carbon, glass, aramid or basalt and matrices based on epoxy resins brings, among many indisputable advantages (low weight, high effectiveness, easy application etc. also some disadvantages. One of the major disadvantages is a low fire resistance of these materials due to the low glass transition temperature Tg of the resin used. Based on an extensive research of strengthening of historic structures with FRP materials [1], the article outlines possible approaches to this problem, especially while strengthening timber load- bearing structures of historic buildings.

  14. 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.

  15. 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.

  16. 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)

  17. 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.

  18. 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.

  19. 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.

  20. Simulation of the FRP Product

    Science.gov (United States)

    Paugam, Ronan; Wooster, Martin; Johnston, Joshua; Gastellu-Etchegorry, Jean-Philippe

    2014-05-01

    Among the different alternative of remote sensing technologies for estimating global fire carbon emission, the thermally-based measures of fire radiative power (FRP; and its temporal integration, fire radiative energy or FRE) has the potential to capture the spatial and temporal variability of fire occurrence. It was shown that a strong linear relationship exists between the total amount of thermal radiant energy emitted by a fire over its lifetime (the FRE) and the amount of fuel burned. Since all vegetation is 50(±5)% carbon, it is therefore in theory a potentially simple matter to measure the FRE and estimate the carbon release. In a fire inventory like the Global Fire Assimilation System (GFAS), the total carbon emission is derived from a gridded FRE product forced by the MODIS observation, using Ct = β x FRE x Ef, where β is a conversion factor initially estimated from small scale experiment as β=0.368 and later derived for different bio dome by comparison with the Global Fire Emission Database (GFED). The sensitivities of the above equation to (i) different types of fire activity (ie, flaming, smoldering, torching), (ii) sensor view angles or (iii) soot/smoke absorption have not yet been well studied. The investigation of these types of sensitivity, and of the information content of thermal IR observations of actively burning fires in general, is one of the primary subjects of this study. Our approach is based on a combination of observational work and simulations conducted via the linkage of different fire models and the 3D radiative transfer (RT) model DART operating in the thermal domain. The radiation properties of a fire as seen from above its plume (e.g. space/air borne sensor) depend on the temperature distribution, the gas concentration (mainly CO2, H2O), and the amount, shape, distribution and optical properties of the soot particles in the flame (where they are emitting) and in the cooling plume (where they are mainly absorbing). While gas and

  1. Global Loads on FRP Ship Hulls

    DEFF Research Database (Denmark)

    Pedersen, Preben Terndrup

    1997-01-01

    Fibre reinforced plastic (FRP) composites used for high-speed vessels have lower modulus of elasticity than the conventionally used steels.Therefore, for large fast ships the lowest natural frequencies of the global hull modes can be relatively low compared to the frequency of waveencounter....... As part of the NoKoS project it was decided to investigate the effect of hull flexibility on the wave-induced as well as accidental structural loads on high-speed ships.Especially it was decided to determine whether there is an upper size of FRP and aluminium mono-hulls caused by continuous wave action...

  2. 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.

  3. 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

  4. Experimental Analysis of Tensile Mechanical Properties of Sprayed FRP

    Directory of Open Access Journals (Sweden)

    Zhao Yang

    2016-01-01

    Full Text Available To study the tensile mechanical properties of sprayed FRP, 13 groups of specimens were tested through uniaxial tensile experiments, being analyzed about stress-strain curve, tensile strength, elastic modulus, breaking elongation, and other mechanical properties. Influencing factors on tensile mechanical properties of sprayed FRP such as fiber type, resin type, fiber volume ratio, fiber length, and composite thickness were studied in the paper too. The results show that both fiber type and resin type have an obvious influence on tensile mechanical properties of sprayed FRP. There will be a specific fiber volume ratio for sprayed FRP to obtain the best tensile mechanical property. The increase of fiber length can lead to better tensile performance, while that of composite thickness results in property degradation. The study can provide reference to popularization and application of sprayed FRP material used in structure reinforcement.

  5. FRP strengthening of RC walls with openings

    DEFF Research Database (Denmark)

    Hansen, Christian Skodborg; Sas, Gabriel; Täljsten, Björn

    2009-01-01

    Strengthening reinforced concrete (RC) walls with openings using fibre reinforced polymers (FRP) has been experimentally proven to be a viable rehabilitation method. However, very few theoretical investigations are reported. In this paper two methods of analysis are presented. Since openings vary...... in size, the analysis of a strengthened wall can be divided into frame idealization method for large openings, and combined disk and frame analysis for smaller openings. The first method provides an easy to use tool in practical engineering, where the latter describes the principles of a ductile...

  6. 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

  7. Fabrication and experimentation of FRP helical spring

    Science.gov (United States)

    Ekanthappa, J.; Shiva Shankar, G. S.; Amith, B. M.; Gagan, M.

    2016-09-01

    In present scenario, the automobile industry sector is showing increased interest in reducing the unsprung weight of the automobile & hence increasing the fuel Efficiency. One of the feasible sub systems of a vehicle where weight reduction may be attempted is vehicle- suspension system. Usage of composite material is a proven way to lower the component weight without any compromise in strength. The composite materials are having high specific strength, more elastic strain energy storage capacity in comparison with those of steel. Therefore, helical coil spring made of steel is replaceable by composite cylindrical helical coil spring. This research aims at preparing a re-usable mandrel (mould) of Mild steel, developing a setup for fabrication, fabrication of FRP helical spring using continuous glass fibers and Epoxy Resin (Polymer). Experimentation has been conducted on fabricated FRP helical spring to determine its strength parameters & for failure analysis. It is found that spring stiffness (K) of Glass/Epoxy helical-spring is greater than steel-coil spring with reduced weight.

  8. 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.

  9. An Expert System in FRP Composite Material Design

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    An expert system prototype for fibre-reinforced plastic matrix (FRP) composite material design,ESFRP, has been developed. The system consists of seven main functional parts: a general inference engine, a set of knowledge bases, a material properties algorithm base, an explanation engine, various data bases, several function models and the user interface. The ESFRP can simulate human experts to make design scheme for fibre-reinforced plastics design, FRP layered plates design and FRP typical engineering components design. It can also predict the material properties and make strength analysis according to the micro and macro mechanics of composite materials. A satisfied result can be gained through the reiterative design.

  10. 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.

  11. Durability of concrete structures strengthened with FRP laminates

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Based on the fast freeze-thaw cycling test, the alkaline immersion test, the water immersion test and the wet-thermal exposure test, the influence of aggressive environments on mechanical behavior of FRP was studied. CFRP specimens subjected to aggressive environments showed good durability with no significant degradation in tensile strength and modulus; however, GFRP specimens exhibited a little decrease in mechanical property after aggressive environments exposure. Based on the fast freeze-thaw cycling test and the wet-thermal exposure test, the influence of aggressive environments on the bond behavior between FRP and concrete, mechanical behavior of concrete beams and columns strengthened with FRP laminates was studied. The results showed that the bond strength had a significant decrease compared with those specimens kept at room temperature, and the specimens strengthened with FRP exhibited good durability.

  12. Anchoring FRP laminates for the seismic strengthening of RC columns

    OpenAIRE

    Sadone, Raphaëlle; Quiertant, Marc; FERRIER, Emmanuel; Chataigner, Sylvain; Mercier, Julien

    2012-01-01

    This paper aims to examine the effectiveness of seismic strengthening of reinforced concrete (RC) columns by externally bonded Fibre Reinforced Polymer (FRP). Particularly, a novel strengthening system, designed for the flexural strengthening of columns is studied. This flexural strengthening is achieved by FRP plates bonded longitudinally and anchored at the column-stub junction. The proposed system is validated through an experimental campaign carried out on full-scale RC columns. Different...

  13. 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...

  14. 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.

  15. TESTS ON STRUCTURALLY DEFICIENT RC SLABS STRENGTHENED WITH FIBRE REINFORCED POLYMER (FRP) COMPOSITES

    Institute of Scientific and Technical Information of China (English)

    S.T. Smith; S.J. Kim

    2004-01-01

    This paper reports the results of a series of tests on fibre reinforced polymer (FRP) strengthened reinforced concrete (RC) slabs, which were recently undertaken at the University of Technology,Sydney. The slabs were reinforced with high-strength low-ductile steel reinforcement and strengthened with either carbon FRP (CFRP) or glass FRP (GFRP) composites. The unstrengthened control slabs failed by fracture of the steel tension reinforcement while the FRP strengthened slabs failed by debonding of the FRP followed by rupture of the tension steel. The FRP-strengthened slabs were stronger than their unstrengthened counterparts and displayed considerable ductility.

  16. 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.

  17. 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

  18. FRP Composites Strengthening of Concrete Columns under Various Loading Conditions

    Directory of Open Access Journals (Sweden)

    Azadeh Parvin

    2014-04-01

    Full Text Available This paper provides a review of some of the progress in the area of fiber reinforced polymers (FRP-strengthening of columns for several loading scenarios including impact load. The addition of FRP materials to upgrade deficiencies or to strengthen structural components can save lives by preventing collapse, reduce the damage to infrastructure, and the need for their costly replacement. The retrofit with FRP materials with desirable properties provides an excellent replacement for traditional materials, such as steel jacket, to strengthen the reinforced concrete structural members. Existing studies have shown that the use of FRP materials restore or improve the column original design strength for possible axial, shear, or flexure and in some cases allow the structure to carry more load than it was designed for. The paper further concludes that there is a need for additional research for the columns under impact loading senarios. The compiled information prepares the ground work for further evaluation of FRP-strengthening of columns that are deficient in design or are in serious need for repair due to additional load or deterioration.

  19. FRP/steel composite damage acoustic emission monitoring and analysis

    Science.gov (United States)

    Li, Dongsheng; Chen, Zhi

    2015-04-01

    FRP is a new material with good mechanical properties, such as high strength of extension, low density, good corrosion resistance and anti-fatigue. FRP and steel composite has gotten a wide range of applications in civil engineering because of its good performance. As the FRP/steel composite get more and more widely used, the monitor of its damage is also getting more important. To monitor this composite, acoustic emission (AE) is a good choice. In this study, we prepare four identical specimens to conduct our test. During the testing process, the AE character parameters and mechanics properties were obtained. Damaged properties of FRP/steel composite were analyzed through acoustic emission (AE) signals. By the growing trend of AE accumulated energy, the severity of the damage made on FRP/steel composite was estimated. The AE sentry function has been successfully used to study damage progression and fracture emerge release rate of composite laminates. This technique combines the cumulative AE energy with strain energy of the material rather than analyzes the AE information and mechanical separately.

  20. Experimental evaluation and field implementation of FRP bridge deck modules

    Directory of Open Access Journals (Sweden)

    Woraphot Prachasaree

    2008-07-01

    Full Text Available Construction of highway bridge decks using fiber reinforced polymer (FRP composite deck and superstructuremodules in lieu of concrete decks has proven to be feasible. However, FRP’s are not widely accepted yet despite theirbenefits such as non-corrosiveness, higher strength to weight ratio, and better fatigue resistance than conventional materials.Lack of wider usage of FRP material is mainly attributed to the absence of: 1 standardized test procedures, 2 designspecifications, and 3 construction procedures. The higher initial cost is also inhibiting bridge engineers in selecting FRPmodules as highway bridge super structural systems.Implementation of FRP composites technology for highway bridge decks leads to higher safety and lower life cyclecosts. Significant ongoing research and development of FRP deck modules as illustrated herein, has proven to enhancedeck module properties in developing FRP modules with enhanced structural performance.Prodeck 4 is one such multicellular deck that was recently developed, and extensively evaluated for static and fatigueloads, and its response results are presented herein. From rigorous testing, it was concluded that Prodeck 4 could resistAASHTO HS 25 loading with maximum stringer spacing of 48 inches. This led to construction of two bridges (one in Ohioand other in West Virginia using Prodeck 4 as decking.

  1. FRP Composites for Retrofit and Construction of Structures:Recent Research at The Hong Kong Polytechnic University

    Institute of Scientific and Technical Information of China (English)

    腾锦光

    2004-01-01

    @@ At The Hong Kong Polytechnic University, on-going research addresses many aspects of the theory of FRP-strengthened structures and the innovative use of FRP composites in new construction. A very brief summary of some of the recent research progresses made at The Hong Kong Polytechnic University (PolyU) is given here. Further details of these recent developments can be found in the references listed at the end. Some of the research summarized here has been carried out in collaboration with researchers at other institutions, including the University of Edinburgh, Tsinghua University, Zhejiang University, the University of Adelaide, Fuzhou University, Jinan University and the National Engineering Research Centre for Diagnosis and Rehabilitation of Industrial Buildings.

  2. Concrete-Filled-Large Deformable FRP Tubular Columns under Axial Compressive Loading

    Directory of Open Access Journals (Sweden)

    Omar I. Abdelkarim

    2015-10-01

    Full Text Available The behavior of concrete-filled fiber tubes (CFFT polymers under axial compressive loading was investigated. Unlike the traditional fiber reinforced polymers (FRP such as carbon, glass, aramid, etc., the FRP tubes in this study were designed using large rupture strains FRP which are made of recycled materials such as plastic bottles; hence, large rupture strain (LRS FRP composites are environmentally friendly and can be used in the context of green construction. This study performed finite element (FE analysis using LS-DYNA software to conduct an extensive parametric study on CFFT. The effects of the FRP confinement ratio, the unconfined concrete compressive strength ( , column size, and column aspect ratio on the behavior of the CFFT under axial compressive loading were investigated during this study. A comparison between the behavior of the CFFTs with LRS-FRP and those with traditional FRP (carbon and glass with a high range of confinement ratios was conducted as well. A new hybrid FRP system combined with traditional and LRS-FRP is proposed. Generally, the CFFTs with LRS-FRP showed remarkable behavior under axial loading in strength and ultimate strain. Equations to estimate the concrete dilation parameter and dilation angle of the CFFTs with LRS-FRP tubes and hybrid FRP tubes are suggested.

  3. A mechanical model for FRP-strengthened beams in bending

    Directory of Open Access Journals (Sweden)

    P. S. Valvo

    2012-10-01

    Full Text Available We analyse the problem of a simply supported beam, strengthened with a fibre-reinforced polymer (FRP strip bonded to its intrados and subjected to bending couples applied to its end sections. A mechanical model is proposed, whereby the beam and FRP strip are modelled according to classical beam theory, while the adhesive and its neighbouring layers are modelled as an interface having a piecewise linear constitutive law defined over three intervals (elastic response – softening response – debonding. The model is described by a set of differential equations with appropriate boundary conditions. An analytical solution to the problem is determined, including explicit expressions for the internal forces, displacements and interfacial stresses. The model predicts an overall non-linear mechanical response for the strengthened beam, ranging over several stages: from linearly elastic behaviour to damage, until the complete detachment of the FRP reinforcement.

  4. Dynamic Characterization of an All-FRP Bridge

    Science.gov (United States)

    Casalegno, C.; Russo, S.

    2017-03-01

    The light weight and high deformability of bridges made with pultruded FRP (fiber-reinforced polymer) materials make them very promising, but, at the same time, vulnerable to dynamic loadings. As a consequence, the vibration serviceability limit state can govern their design. There is currently a lack of data about the dynamic characteristics of FRP bridges and of design guidelines for securing their vibration serviceability. The paper presents the results of dynamic testing and characterization of an all-FRP spatial footbridge. The main modal parameters of the bridge are evaluated by an experimental modal analysis and by comparison of experimental data with FE analysis results. The identified flexural and torsional modes of the bridge are characterized by relatively high values of frequencies and damping. Results of the dynamic characterization give useful information about the dynamic characteristics of this kind of structures and can contribute to the elaboration of future guidelines for providing them with the vibration serviceability.

  5. New Strengthening Techniques with FRP Laminates and Interfacial Fracture Theories

    Institute of Scientific and Technical Information of China (English)

    Hong YUAN; Zhishen WU

    2000-01-01

    The use of FRP composites in the form of sheet or plate bonded to the large-scale RC structures is becoming an increasing attractive solution to the strengthening of existing structures. Compared with traditional steel plate strengthening, FRP possesses excellent behavior such as lightness in weight, high strength-to-weight and stiffness-to-weight ratio, high corrosion and fatigue resistance, electronic neutrality, and great efficiency in construction. A important failure mode for FRP-strengthened structures is debondings.Therefore, the LEFM and NLFM are utilized to treat this problem. Closed form expressions for energy release rate, load-carrying capacity, load-displacement relation and interfacial crack propagation are obtained, in which a local shear stress-slip law with softening is adopted.

  6. 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.

  7. 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

  8. 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)

  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. Analysis and behaviour of FRP-confined short concrete columns subjected to eccentric loading

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Fibre-reinforced polymer (FRP) composites were widely utilized in civil engineering structures as the retrofit of reinforced concrete (RC) columns. To design FRP jackets safely and economically, the behaviour of such columns should be predicted first. This paper is concerned with the analysis and behaviour of FRP-confined RC circular and rectangular short columns subjected to eccentric loading. A simple design-oriented stress-strain model for FRP-confined concrete in a section analysis was first proposed. The accuracy was then proved by two test data. Following that, a parametric study including amount of FRP confinement, FRP strain capacity, unconfined concrete strength and shape of column section is provided. Some conclusions were obtained at the end of the paper. The work here will provide a comprehensive understanding of the behaviour of FRP-confined concrete columns. The simplicity of the model also enables a simple equivalent stress block to be developed for direct use in practical design.

  11. 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...

  12. FRP-Confined Recycled Coarse Aggregate Concrete: Experimental Investigation and Model Comparison

    Directory of Open Access Journals (Sweden)

    Yingwu Zhou

    2016-10-01

    Full Text Available The in situ application of recycled aggregate concrete (RAC is of great significance in environmental protection and construction resources sustainability. However, it has been limited to nonstructural purposes due to its poor mechanical performance. External confinement using steel tubes and fiber-reinforced polymer (FRP can significantly improve the mechanical performance of RAC and thus the first-ever study on the axial compressive behavior of glass FRP (GFRP-confined RAC was recently reported. To have a full understanding of FRP-confined RAC, this paper has extended the type of FRP and presents a systematic experimental study on the axial compressive performance of carbon FRP (CFRP-confined RAC. The mechanical properties of CFRP-confined RAC from the perspective of the failure mode, ultimate strength and strain, and stress–strain relationship responses were analyzed. Integrated with existing experimental data of FRP-confined RAC, the paper compiles a database for the mechanical properties of FRP-confined RAC. Based on the database, the effects of FRP type (i.e., GFRP and CFRP and the replacement ratio of recycled coarse aggregate were investigated. The results indicated that the stress–stain behavior of FRP-confined RAC depended heavily on the unconfined concrete strength and the FRP confining pressure instead of the replacement ratio. Therefore, this study adopted eleven high-performance ultimate strength and strain models developed for FRP-confined normal aggregate concrete (NAC to predict the mechanical properties of FRP-confined RAC. All the predictions had good agreement with the test results, which further confirmed similar roles played by FRP confinement in improving the mechanical properties of RAC and improving those of NAC. On this basis, this paper finally recommended a stress–strain relationship model for FRP-confined RAC.

  13. 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.

  14. Fire performance of basalt FRP mesh reinforced HPC thin plates

    DEFF Research Database (Denmark)

    Hulin, Thomas; Hodicky, Kamil; Schmidt, Jacob Wittrup;

    2013-01-01

    An experimental program was carried out to investigate the influence of basalt FRP (BFRP) reinforcing mesh on the fire behaviour of thin high performance concrete (HPC) plates applied to sandwich elements. Samples with BFRP mesh were compared to samples with no mesh, samples with steel mesh...

  15. Mechanical anchorage of FRP tendons – A literature review

    DEFF Research Database (Denmark)

    Schmidt, Jacob W.; Bennitz, Anders; Täljsten, Björn

    2012-01-01

    anchorage systems for use with Aramid, Glass and Carbon FRP tendons have been proposed over the last two decades. Each system is usually tailored to a particular type of tendon. This paper presents a brief overview of bonded anchorage applications while the primary literature review discusses three methods...

  16. 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.

  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. 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

  19. Structural performance of complex core systems for FRP-balsa composite sandwich bridge decks

    OpenAIRE

    Osei-Antwi, Michael

    2014-01-01

    Based on current fiber-reinforced polymer (FRP) composite construction principles, FRP decks fall into two categories: pultruded decks and sandwich decks. Sandwich decks comprise face sheets and either honeycombs or foams reinforced with internal FRP webs for shear resistance. The honeycomb structure and the webs cause debonding between the upper face sheets and the core due to the uneven support of the former. An alternative material that has high shear capacity and can provide uniform ...

  20. Compressive Strength of a Longitudinally Stiffened FRP Panel

    DEFF Research Database (Denmark)

    Riber, Hans Jørgen; Jensen, Jørgen Juncher; Pedersen, Preben Terndrup

    1997-01-01

    A structural analysis of a cross stiffened orthotropic FRP panel subjected to uni-axial compressive load is crarried out. Analytical Calculations of the strength of the panel are presented and compared to finite element analysis performed by different authors. Both analytica and finite element ap...... approaches confirm an identical failrue scenario. In the present case, the load carrying capacity of the stiffened panel is limited by the plate stiffener debonding stress....

  1. Modeling of FRP-jacketed RC columns subject to combined axial and lateral loads

    OpenAIRE

    Lee, Chung-Sheng

    2006-01-01

    To successfully use the fiber-reinforced-polymer (FRP) overlay technique for the seismic retrofit and the blast- hardening of RC columns, the mechanical behavior of the FRP-confined concrete needs to be understood and its response needs to be accurately predicted. Although a number of studies have been conducted to-date, it is still not clear how the main parameters affect the axial stress- strain response of a FRP-confined concrete cylinder. In particular, while it is understood that FRP jac...

  2. A Review on Strengthening Steel Beams Using FRP under Fatigue

    Directory of Open Access Journals (Sweden)

    Mohamed Kamruzzaman

    2014-01-01

    Full Text Available In recent decades, the application of fibre-reinforced polymer (FRP composites for strengthening structural elements has become an efficient option to meet the increased cyclic loads or repair due to corrosion or fatigue cracking. Hence, the objective of this study is to explore the existing FRP reinforcing techniques to care for fatigue damaged structural steel elements. This study covers the surface treatment techniques, adhesive curing, and support conditions under cyclic loading including fatigue performance, crack propagation, and failure modes with finite element (FE simulation of the steel bridge girders and structural elements. FRP strengthening composites delay initial cracking, reduce the crack growth rate, extend the fatigue life, and decrease the stiffness decay with residual deflection. Prestressed carbon fibre-reinforced polymer (CFRP is the best strengthening option. End anchorage prevents debonding of the CRRP strips at the beam ends by reducing the local interfacial shear and peel stresses. Hybrid-joint, nanoadhesive, and carbon-flex can also be attractive for strengthening systems.

  3. 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.

  4. 46 CFR 160.035-12 - Additional preapproval tests required for F.R.P. lifeboats.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 6 2010-10-01 2010-10-01 false Additional preapproval tests required for F.R.P... Merchant Vessels § 160.035-12 Additional preapproval tests required for F.R.P. lifeboats. (a) General... p.s.i. of air pressure both before and after the tests described in paragraphs (b)(1) through (6)...

  5. Practical applications of asset management and comakership business models for FRP bridges

    NARCIS (Netherlands)

    Sebastian, R.

    2012-01-01

    Fibre Reinforced Polymer (FRP) material and the associated technologies for bridge construction and refurbishment have been proven to be durable and sustainable. Much research and a number of recent projects have demonstrated that FRP bridges can also be cost-effective, provided that the cost and be

  6. Experimental investigation on FRP to steel adhesively-bonded joint under tensile loading

    NARCIS (Netherlands)

    Jiang, X.; Kolstein, M.H.; Bijlaard, F.S.K.

    2012-01-01

    Due to various advantages of Fibre-Reinforced Polymer (FRP) decks, the FRP to steel composite girder system is being increasingly used in the construction of new bridges as well as the rehabilitation projects of old bridges. This paper focus on the mechanical behaviors and failure modes of the adhes

  7. 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.

  8. Behavior of FRP-Confined Concrete-Filled Steel Tube Columns

    Directory of Open Access Journals (Sweden)

    Yiyan Lu

    2014-05-01

    Full Text Available This paper presents the results of an experimental study into the behavior of concrete-filled steel tube columns confined by fiber-reinforced polymer (FRP. Eleven columns were tested to investigate the effects of the FRP layer number, the thickness of the steel tube and concrete strength on their load capacity and axial deformation capacity. The experimental results indicated that the FRP wrap can effectively confine the concrete expansion and delay the local buckling of the steel tube. Both the load capacity and the axial deformation capacity of concrete-filled steel tube columns can be substantially enhanced with FRP confinement. A model is proposed to predict the load capacity of the FRP-confined concrete-filled steel tube columns. The predicted results are generally in good agreement with the experimental ones obtained in this study and in the literature.

  9. Analytical and Numerical Modelling of FRP Debonding from Concrete Substrate under Pure Shearing

    Institute of Scientific and Technical Information of China (English)

    PAN Jinlong; XU Zhun; C K Y Leung; LI Zongjin

    2012-01-01

    External bonding of fiber reinforced polymer (FRP) composites on the concrete structures has been proved to be an effective and efficient way to strengthen concrete structures.For a FRP strengthened concrete beam,it is usually observed that the failure occurs in the concrete and a thin layer of concrete is attached on the surface of the debonded FRP plate.To study the debond behavior between concrete and FRP composites,an analytical model based on the three-parameter model is developed to study the debonding behavior for the FRP-to-concrete joint under pure shearing.Then,nonlinear FEM analysis is conducted to verify the proposed analytical model.The FEM results shows good agreement with the results from the model.Finally,with the analytical model,sensitivity analyses are performed to study the effect of the interfacial parameters or the geometric parameters on the debonding behavior.

  10. 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...

  11. Repair of corrosion-damaged columns using FRP wraps

    Science.gov (United States)

    Baiyasi, Mohamad Imad

    Many bridge columns in Michigan are damaged by chloride contamination resulting in the corrosion of the steel reinforcement, and swelling and spalling of the concrete and use of the bridges is typically continued. This in itself may not be a serious problem since most columns in Michigan are over-designed and the loss of strength is not a significant issue. However, the lack of any method to minimize or prevent corrosion of the steel results in continued deterioration and unsightly columns. Polymer composite (also known as fiber-reinforced polymer or FRP) jackets offer a possible remedy to this problem. They offer a rapid repair technique with the potential to enhance the longterm durability and compression strength of damaged columns due to the confinement that is provided when fibers are oriented in the hoop direction. Fibers oriented in the vertical direction can enhance the bending strength. Experiments were conducted to assess the effects of using FRP wraps with fibers oriented in the hoop direction for rehabilitating corrosion-damaged columns. Issues that were explored are: (1) effect of freeze-thaw and wet-dry cycles on the properties of FRP panels; (2) freeze-thaw durability of concrete square and cylindrical specimens wrapped with glass and carbon FRP and subjected to an internal expansive force; and (3) effect of wrapping on the rate of corrosion in an accelerated corrosion test. The results of the freeze-thaw experiment indicate that freeze-thaw cycles have no statistically significant effect on the compressive strength of glass and carbon wrapped specimens. For round specimens, glass and carbon wraps increased the strength by a factor of about 2.3 and 2.6, respectively. For square specimens, glass and carbon wraps increased the strength by a factor of 1.4--1.5. Freeze-thaw conditioning generally reduced the longitudinal failure strain of wrapped specimens. The square wrapped specimens had lower compressive strength compared to the round specimens, even

  12. 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.

  13. 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

    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 provides 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 long term viability of existing nuclear power plants in the U.S. will depend upon maintaining high capacity factors, avoiding nuclear safety issues and reducing operating costs. The slow progress in the construction on new nuclear power plants has placed in increased importance on maintaining the output of the current fleet of nuclear power plants. Recently expanded natural gas production has placed increased economic pressure on nuclear power plants due to lower cost competition. Until recently, power uprate projects had steadily increased the total output of the U.S. nuclear fleet. Errors made during power plant upgrade projects have now removed three nuclear power plants from the U.S. fleet and economic considerations have caused the permanent shutdown of a fourth plant. Additionally, several utilities have cancelled power uprate projects citing economic concerns. For the past several years net electrical generation from U.S. nuclear power plants has been declining. One of few remaining areas where significant improvements in plant capacity factors can be made is in minimizing the duration of refueling outages. Managing nuclear power plant outages is a complex and difficult task. Due to the large number of complex tasks and the uncertainty that accompanies them, outage durations routinely exceed the planned duration. The ability to complete an outage on or near

  14. 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.

  15. 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...

  16. Behaviour of FRP confined concrete in square columns

    Directory of Open Access Journals (Sweden)

    de Diego, A.

    2015-12-01

    Full Text Available A significant amount of research has been conducted on FRP-confined circular columns, but much less is known about rectangular/square columns in which the effectiveness of confinement is much reduced. This paper presents the results of experimental investigations on low strength square concrete columns confined with FRP. Axial compression tests were performed on ten intermediate size columns. The tests results indicate that FRP composites can significantly improve the bearing capacity and ductility of square section reinforced concrete columns with rounded corners. The strength enhancement ratio is greater the lower the concrete strength and also increases with the stiffness of the jacket. The confined concrete behaviour was predicted according to the more accepted theoretical models and compared with experimental results. There are two key parameters which critically influence the fitting of the models: the strain efficiency factor and the effect of confinement in non-circular sections.La mayoría de las investigaciones sobre hormigón confinado con FRP se han realizado sobre pilares de sección circular, pero el comportamiento en secciones cuadradas/rectangulares, donde el confinamiento es menos eficaz, es mucho menos conocido. Este trabajo presenta los resultados de un estudio experimental sobre probetas de hormigón de baja resistencia y sección cuadrada. Se han ensayado a compresión centrada diez probetas de tamaño intermedio. Los resultados indican que el confinamiento mejora significativamente la resistencia y ductilidad del hormigón en columnas de sección cuadrada con las esquinas redondeadas. El incremento de resistencia es mayor cuanto menor es la resistencia del hormigón sin confinar y también aumenta con la rigidez del encamisado. Los resultados se compararon con los obtenidos según los modelos teóricos más aceptados. Hay dos parámetros críticos en el ajuste de los modelos: el factor de eficiencia de la deformación y el

  17. 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

  18. A comparison of FRP-sandwich penetrating impact test methods

    Energy Technology Data Exchange (ETDEWEB)

    Hildebrand, M. [VTT Manufacturing Technology, Espoo (Finland). Maritime and Mechanical Engineering

    1996-12-31

    The main objective of this project is to identify the test methods which provide useful results for the different types of penetrating impacts occurring in sandwich structures. A series of penetrating impact tests on FRP-sandwich panels is performed using three different test methods and the results of the test methods are compared. The test methods used are the standardised method ISO 6603 and two non-standardised methods. The first non-standardised method uses a pyramid-shaped impactor instead of the cylindrical impactor used in the ISO 6603 method. In the second non-standardised method, the impact test is performed quasistatically using a cylindrical impactor. Possible stages of failure occurring in FRP-sandwich during a penetrating impact are illustrated. A comprehensive test method should be able to provoke various failure modes, as observed in impact failures of actual sandwich structures. The results obtained with the three test methods lead to a different ranking in impact strength of the panels. Hence, impact test results obtained with different test methods are not even qualitatively comparable. The pyramid-shaped impactor is able to generate clearly more failure modes than the cylindrical impactor in the ISO 6603 method. Therefore, it is considered to be of more practical value for determining the impact strength of PRP-sandwich structures. (orig.) (15 refs.)

  19. Behavior of FRP Link Slabs in Jointless Bridge Decks

    Directory of Open Access Journals (Sweden)

    Aziz Saber

    2012-01-01

    Full Text Available The paper investigated the use of fiberglass-reinforced plastic (FRP grid for reinforcement in link slabs for jointless bridge decks. The design concept of link slab was examined based on the ductility of the fiberglass-reinforced plastic grid to accommodate bridge deck deformations. The implementation of hybrid simulation assisted in combining the experimental results and the theoretical work. The numerical analyses and the experimental work investigated the behavior of the link slab and confirmed its feasibility. The results indicated that the technique would allow simultaneous achievement of structural need, lower flexural stiffness of the link slab approaching the behavior of a hinge, and sustainability need of the link slab. The outcome of the study supports the contention that jointless concrete bridge decks may be designed and constructed with fiberglass-reinforced plastic grid link slabs. This concept would also provide a solution to a number of deterioration problems associated with bridge deck joints and can be used during new construction of bridge decks. The federal highway administration provided funds to Louisiana Department of Transportation through the innovative bridge research and development program to implement the use of FRP grid as link slab.

  20. Experimental study on seismic behavior of circular RC columns strengthened with pre-stressed FRP strips

    Science.gov (United States)

    Zhou, Changdong; Lu, Xilin; Li, Hui; Tian, Teng

    2013-12-01

    Bonding fiber reinforced polymer (FRP) has been commonly used to improve the seismic behavior of circular reinforced concrete (RC) columns in engineering practice. However, FRP jackets have a significant stress hysteresis effect in this strengthening method, and pre-tensioning the FRP can overcome this problem. This paper presents test results of 25 circular RC columns strengthened with pre-stressed FRP strips under low cyclic loading. The pre-stressing of the FRP strips, types of FRP strips and longitudinal reinforcement, axial load ratio, pre-damage degree and surface treatments of the specimens are considered as the primary factors in the tests. According to the failure modes and hysteresis curves of the specimens, these factors are analyzed to investigate their effect on bearing capacity, ductility, hysteretic behavior, energy dissipation capacity and other important seismic behaviors. The results show that the initial lateral confined stress provided by pre-stressed FRP strips can effectively inhibit the emergence and development of diagonal shear cracks, and change the failure modes of specimens from brittle shear failure to bending or bending-shear failure with better ductility. As a result, the bearing capacity, ductility, energy dissipation capacity and deformation capacity of the strengthened specimens are all significantly improved.

  1. Study on fabrication of smart FRP-OFBG composite laminates and their sensing properties

    Science.gov (United States)

    Wang, Yanlei; Zhou, Zhi; Ou, Jinping

    2007-01-01

    Fiber reinforced polymer (FRP) has gained much attention in civil engineering due to its high strength-to-weight and stiffness-to-weight ratios, corrosion resistance and good fatigue resistance. Optical Fiber Bragg Grating (OFBG) is now widely accepted as smart sensor due to its advantages of electric-magnetic resistance, small size, distributed sensing, durability, and so on. Combined the FRP with OFBG, new kind of smart FRP-OFBG composite laminates was developed. Fabrication method of the smart composite laminates was introduced in this paper. The study presented the basic principle of OFBG sensors. Then the strain and temperature sensing properties of the proposed smart FRP-OFBG composite laminates were experimentally studied on material test system and under hot water, respectively. The experimental results indicate the strain sensing properties of the smart FRP-OFBG composite laminates are nearly the same as that of bare OFBG, however, the temperature sensing abilities of the smart FRP-OFBG composite laminates are improved and the sensitivity coefficient is nearly 3.2 times as much as that of bare OFBG. The strain and temperature sensing precisions of the smart FRP-OFBG composite laminates are 1 μ\\Vegr and 0.03 °C, respectively. The smart FRYOFBG composite laminates are very proper for application in civil engineering.

  2. Accelerated Testing for Long-Term Durability of Various FRP Laminates for Marine Use

    Science.gov (United States)

    Miyano, Yasushi; Nakada, Masayuki

    The prediction of long-term fatigue life of various FRP laminates combined with resins, fibers and fabrics for marine use under temperature and water environments were performed by our developed accelerated testing methodology based on the time-temperature superposition principle (TTSP). The base material of five kinds of FRP laminates employed in this study was plain fabric CFRP laminates T300 carbon fibers/vinylester (T300/VE). The first selection of FRP laminate to T300/VE was the combinations of different fabrics, that is flat yarn plain fabric T700 carbon fibers/vinylester (T700/VE-F) and multi-axial knitted T700 carbon fibers/vinylester (T700/VE-K) for marine use and the second selection of FRP laminates to T300/VE was the combinations with different fibers and matrix resin, that is plain fabric T300 carbon fibers/epoxy (T300/EP) and plain fabric E-glass fibers/vinylester (E-glass/VE). These five kinds of FRP laminates were prepared under three water absorption conditions of Dry, Wet and Wet C Dry after molding. The three-point bending constant strain rate (CSR) tests for these FRP laminates at three conditions of water absorption were carried out at various temperatures and strain rates. Furthermore, the three-point bending fatigue tests for these specimens were carried out at various temperatures and frequencies. The flexural CSR and fatigue strengths of these five kinds of FRP laminates strongly depend on water absorption as well as time and temperature. The mater curves of fatigue strength as well as CSR strength for these FRP laminates at three water absorption conditions are constructed by using the test data based on TTSP. It is possible to predict the long term fatigue life for these FRP laminates under an arbitrary temperature and water absorption conditions by using the master curves.

  3. 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.

  4. Development of Embedded Vascular Networks in FRP for Active/Passive Thermal Management

    Science.gov (United States)

    2015-04-01

    AFRL-AFOSR-UK-TR-2015-0019 Development of Embedded Vascular Networks in FRP for Active/Passive Thermal Management Katarzyna...To) 30 September 2012 – 31 December 2014 4. TITLE AND SUBTITLE Development of Embedded Vascular Networks in FRP for Active/Passive Thermal...Z39-18     Page 1 of 16     Project  Title:      Development  of   Embedded  Vascular  Networks  in  FRP  for

  5. Biaxial Flexural Strength and Estimation of Size on the Strength Properties of FRP Composites

    Directory of Open Access Journals (Sweden)

    M. N. Saraf

    1990-04-01

    Full Text Available Fibre reinforced plastics (FRP are widely used as structural materials. For designing structural components, a designer is provided with data based on unidirectional testing. But in real structural applications the component is subjected to multiaxial stress throughout the material. Hence a multiaxial test is a better gauge of the behaviour of FRP components in service. In the present paper a ring-on-ring method was adopted which produces biaxial flexural stress on the FRP specimen. Wubull's statistical weakest link theory was applied to standardize the complexity and to assess the reliability of the results.

  6. 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....

  7. 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...

  8. 3D Numerical Realization of FRP Mircrostructure from High-Res X-Ray CT Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Currently, characterization of constituent-level failure in state-of-the-art FRP composites is limited to two-dimensional observations (e.g. using optical or...

  9. Structural Performance of Light Weight Multicellular FRP Composite Bridge Deck Using Finite Element Analysis

    Institute of Scientific and Technical Information of China (English)

    Woraphot Prachasaree; Pongsak Sookmanee

    2012-01-01

    Fiber reinforced polymer (FRP) composite materials having advantages such as higher strength to weight than conventional engineering materials,non-corrosiveness and modularization,which should help engineers to obtain more efficient and cost effective structural materials and systems.Currently,FRP composites are becoming more popular in civil engineering applications.The objectives of this research are to study performance and behavior of light weight multi-cellular FRP composite bridge decks (both module and system levels) under various loading conditions through finite element modeling,and to validate analytical response of FRP composite bridge decks with data from laboratory evaluations.The relative deflection,equivalent flexural rigidity,failure load (mode) and load distribution factors (LDF) based on FE results have been compared with experimental data and discussed in detail.The finite element results showing good correlations with experimental data are presented in this work.

  10. Blast Design of Reinforced Concrete and Masonry Components Retrofitted with FRP

    Science.gov (United States)

    2010-07-01

    ultimate flexural and shear resistance of the upgraded walls. The methodology for estimating the flexural resistance of concrete and masonry components...recommended value not including any environmental effects or debonding The FRP reinforcement is typically applied to a concrete or masonry wall...have enough tensile and shear strength to transfer the force and develop the strength of the bonded FRP reinforcement . The durability of the

  11. Confining concrete with sisal and jute FRP as alternatives for CFRP and GFRP

    Directory of Open Access Journals (Sweden)

    Tara Sen

    2015-12-01

    Full Text Available This research paper presents an experimental investigation on the confinement strength and confinement modulus of concrete cylinders confined using different types of natural fibre composites and a comparative performance analysis with different artificial fibre based composite materials. The paper also highlights the need to switch over from the utilization of artificial fibres, which are non-renewable and fossil fuel products, to environmental beneficial materials like green fibres. The utilization of plant products like sisal and jute fibres and their composites in various structural engineering applications addresses the issues of sustainability and renewability with constructional materials. The paper describes a suitable mechanical treatment method like high temperature conditioning, which aids us in further improving the properties of these woven natural materials like sisal and jute for composite fabrication and utilization. Heat treated natural fibres of woven sisal and jute were utilized for confining concrete cylinders similar to CFRP and GFRP confinement and their confinement characteristics were obtained and compared. All the cylinders were subjected to monotonic axial compressive loads, so as to evaluate the effect of confinement on the axial load carrying capacity and all their failure modes were discussed thoroughly. The results indicated superior performance by sisal FRP as well as jute FRP confined cylinders as compared to controlled or unconfined cylinders, also sisal FRP wrapped cylinders displayed ultimate axial load of comparable magnitude to CFRP confinement. Natural FRP confinement displayed superior confinement modulus and confinement strength, also the ultimate axial load of concrete cylinders confined with natural FRPs underwent 66% enhancement by sisal FRP and 48% enhancement by jute FRP, in comparison with controlled or unconfined cylinders. Enhancement in axial load carrying capacity was 83% with CFRP confinement

  12. Effect of Chloride Content on Bond Behavior Between FRP and Concrete

    Institute of Scientific and Technical Information of China (English)

    潘金龙; 黄毅方; 邢锋

    2010-01-01

    For reinforced concrete structures located along the seaside, the penetration of chloride ions into concrete may be a threat to the durability of the structures. Experimental investigations were carried out to study the effect of chloride content on the bond behavior between concrete and fiber reinforced polymer (FRP) plates. Direct shear tests were conducted on the FRP strengthened concrete members. Before testing, the specimens were immersed in NaCl solutions with concentrations ranging from 3%—15% for di...

  13. 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.

  14. 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...

  15. 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...

  16. 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.

  17. 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.

  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. 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. 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.

  1. 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

  2. Behaviour of concrete beams reinforced withFRP prestressed concrete prisms

    Science.gov (United States)

    Svecova, Dagmar

    The use of fibre reinforced plastics (FRP) to reinforce concrete is gaining acceptance. However, due to the relatively low modulus of FRP, in comparison to steel, such structures may, if sufficient amount of reinforcement is not used, suffer from large deformations and wide cracks. FRP is generally more suited for prestressing. Since it is not feasible to prestress all concrete structures to eliminate the large deflections of FRP reinforced concrete flexural members, researchers are focusing on other strategies. A simple method for avoiding excessive deflections is to provide sufficiently high amount of FRP reinforcement to limit its stress (strain) to acceptable levels under service loads. This approach will not be able to take advantage of the high strength of FRP and will be generally uneconomical. The current investigation focuses on the feasibility of an alternative strategy. This thesis deals with the flexural and shear behaviour of concrete beams reinforced with FRP prestressed concrete prisms. FRP prestressed concrete prisms (PCP) are new reinforcing bars, made by pretensioning FRP and embedding it in high strength grout/concrete. The purpose of the research is to investigate the feasibility of using such pretensioned rebars, and their effect on the flexural and shear behaviour of reinforced concrete beams over the entire loading range. Due to the prestress in the prisms, deflection of concrete beams reinforced with this product is substantially reduced, and is comparable to similarly steel reinforced beams. The thesis comprises both theoretical and experimental investigations. In the experimental part, nine beams reinforced with FRP prestressed concrete prisms, and two companion beams, one steel and one FRP reinforced were tested. All the beams were designed to carry the same ultimate moment. Excellent flexural and shear behaviour of beams reinforced with higher prestressed prisms is reported. When comparing deflections of three beams designed to have the

  3. 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.

  4. Constitutive Modeling and Numerical Simulation of Frp Confined Concrete Specimens

    Science.gov (United States)

    Smitha, Gopinath; Ramachandramurthy, Avadhanam; Nagesh, Ranganatha Iyer; Shahulhameed, Eduvammal Kunhimoideen

    2014-09-01

    Fiber-reinforced polymer (FRP) composites are generally used for the seismic retrofit of concrete members to enhance their strength and ductility. In the present work, the confining effect of Carbon Fiber-Reinforced Polymer (CFRP) composite layers has been investigated by numerical simulation. The numerical simulation has been carried out using nonlinear finite element analysis (FEA) to predict the response behaviour of CFRP-wrapped concrete cylinders. The nonlinear behaviour of concrete in compression and the linear elastic behaviour of CFRP has been modeled using an appropriate constitutive relationship. A cohesive model has been developed for modeling the interface between the concrete and CFRP. The interaction and damage failure criteria between the concrete to the cohesive element and the cohesive element to the CFRP has also been accounted for in the modeling. The response behaviour of the wrapped concrete specimen has been compared with the proposed interface model and with a perfectly bonded condition. The results obtained from the present study showed good agreement with the experimental load-displacement response and the failure pattern in the literature. Further, a sensitivity analysis has been carried out to study the effect of the number of layers of CFRP on the concrete specimens. It has been observed that wrapping with two layers was found to be the optimum, beyond which the response becomes flexible but with a higher load-carrying capacity

  5. Bond strength investigations and structural applicability of composite fiber-reinforced polymer (FRP) rebars

    Science.gov (United States)

    Kachlakev, Damian Ivanov

    The composite FRP rebars research at Oregon State University was initiated in 1993 principally to develop a non-metallic hollow reinforcement. It was recognized that the tensile properties of such reinforcement are unquestionably superior to steel, but its performance in concrete could be problematic. The bond between FRP rebars and concrete was identified as a critical area of concern. The purpose of this study is (i) to analyze a variety of FRP and steel reinforcing units; (ii) to advance the knowledge of bond mechanism, failure modes, and parameters influencing the bond strength; (iii) to compare composite rebars to conventional steel and to assess their applicability as reinforcing members. Commercially available FRP rebars were investigated. Particular emphasis was given to a hollow glass FRP rod designed at Oregon State University. Several parameters were investigated, including: failure mode, concrete compressive strength, rebar diameter and circumference/cross section ratio, embedment length, concrete cover, and microstructure of the composite rebars. It was recognized that the ASTM C234-90 pull-out standard is test of concrete strength. Therefore, a modified pull-out test was developed for evaluating the bond strength behavior. A newly developed European bond test procedure was compared with locally modified version of the pull-out method. The new procedure was used for the first time in the United States. The study demonstrated a phenomenon, not reported in the published research at this time, defined as a size effect. The size effects result in lower bond strength with increasing area of the interface between FRP bars and concrete. The next phase of the research was dedicated to the hollow glass FRP rebar. The goal was to compare its bond properties to conventional steel and solid FRP bars. The study led to two new phenomena not described in the literature previously. Results showed that the concrete compressive strength does not significantly affect the

  6. Moment-Curvature Behaviors of Concrete Beams Singly Reinforced by Steel-FRP Composite Bars

    Directory of Open Access Journals (Sweden)

    Zeyang Sun

    2017-01-01

    Full Text Available A steel-fiber-reinforced polymer (FRP composite bar (SFCB is a kind of rebar with inner steel bar wrapped by FRP, which can achieve a better anticorrosion performance than that of ordinary steel bar. The high ultimate strength of FRP can also provide a significant increase in load bearing capacity. Based on the adequate simulation of the load-displacement behaviors of concrete beams reinforced by SFCBs, a parametric analysis of the moment-curvature behaviors of concrete beams that are singly reinforced by SFCB was conducted. The critical reinforcement ratio for differentiating the beam’s failure mode was presented, and the concept of the maximum possible peak curvature (MPPC was proposed. After the ultimate curvature reached MPPC, it decreased with an increase in the postyield stiffness ratio (rsf, and the theoretical calculation method about the curvatures before and after the MPPC was derived. The influence of the reinforcement ratio, effective depth, and FRP ultimate strain on the ultimate point was studied by the dimensionless moment and curvature. By calculating the envelope area under the moment-curvature curve, the energy ductility index can obtain a balance between the bearing capacity and the deformation ability. This paper can provide a reference for the design of concrete beams that are reinforced by SFCB or hybrid steel bar/FRP bar.

  7. Behavior of FRP Bars-Reinforced Concrete Slabs under Temperature and Sustained Load Effects

    Directory of Open Access Journals (Sweden)

    Hizia Bellakehal

    2014-03-01

    Full Text Available The large temperature variation has a harmful effect on concrete structures reinforced with fiber reinforced polymer (FRP bars. This is due to the significant difference between transverse coefficient of thermal expansion of these bars and that of the hardened concrete. This difference generates a radial pressure at the FRP bar/concrete interface, and may cause splitting cracks within concrete. This paper presents results of an experimental and analytical study carried out on FRP-reinforced concrete slabs subjected, simultaneously, to thermal and mechanical loads. The analytical model based on the theory of linear elasticity consists to evaluate combined effects of thermal and mechanical loads on the transverse expansion of FRP bars. Parameters studied in this investigation are the concrete cover thickness, FRP bar diameter, and the temperature variation. The thermal cycles were varied from −30 to +60 °C. Comparisons between analytical and experimental results show that transverse strains predicted from the proposed model are in good correlation with experimental results.

  8. An investigation into the impact of cryogenic environment on mechanical stresses in FRP composites

    Science.gov (United States)

    Fifo, O.; Basu, B.

    2015-07-01

    Fibre reinforced polymer (FRP) composites are fast becoming a highly utilised engineering material for high performance applications due to their light weight and high strength. Carbon fibre and other high strength fibres are commonly used in design of aerospace structures, wind turbine blades, etc. and potentially for propellant tanks of launch vehicles. For the aforementioned fields of application, stability of the material is essential over a wide range of temperature particularly for structures in hostile environments. Many studies have been conducted, experimentally, over the last decade to investigate the mechanical behaviour of FRP materials at varying subzero temperature. Likewise, tests on aging and cycling effect (room to low temperature) on the mechanical response of FRP have been reported. However, a relatively lesser focused area has been the mechanical behaviour of FRP composites under cryogenic environment. This article reports a finite element method of investigating the changes in the mechanical characteristics of an FRP material when temperature based analysis falls below zero. The simulated tests are carried out using a finite element package with close material properties used in the cited literatures. Tensile test was conducted and the results indicate that the mechanical responses agree with those reported in the literature sited.

  9. Distributed Long-Gauge Optical Fiber Sensors Based Self-Sensing FRP Bar for Concrete Structure.

    Science.gov (United States)

    Tang, Yongsheng; Wu, Zhishen

    2016-02-25

    Brillouin scattering-based distributed optical fiber (OF) sensing technique presents advantages for concrete structure monitoring. However, the existence of spatial resolution greatly decreases strain measurement accuracy especially around cracks. Meanwhile, the brittle feature of OF also hinders its further application. In this paper, the distributed OF sensor was firstly proposed as long-gauge sensor to improve strain measurement accuracy. Then, a new type of self-sensing fiber reinforced polymer (FRP) bar was developed by embedding the packaged long-gauge OF sensors into FRP bar, followed by experimental studies on strain sensing, temperature sensing and basic mechanical properties. The results confirmed the superior strain sensing properties, namely satisfied accuracy, repeatability and linearity, as well as excellent mechanical performance. At the same time, the temperature sensing property was not influenced by the long-gauge package, making temperature compensation easy. Furthermore, the bonding performance between self-sensing FRP bar and concrete was investigated to study its influence on the sensing. Lastly, the sensing performance was further verified with static experiments of concrete beam reinforced with the proposed self-sensing FRP bar. Therefore, the self-sensing FRP bar has potential applications for long-term structural health monitoring (SHM) as embedded sensors as well as reinforcing materials for concrete structures.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. Pretreatment of Woven Jute FRP Composite and Its Use in Strengthening of Reinforced Concrete Beams in Flexure

    Directory of Open Access Journals (Sweden)

    Tara Sen

    2013-01-01

    Full Text Available Environmental awareness motivates researchers worldwide to perform studies of natural fibre reinforced polymer composites, as they come with many advantages and are primarily sustainable. The present study aims at evaluating the mechanical characteristics of natural woven jute fibre reinforced polymer (FRP composite subjected to three different pretreatments, alkali, benzyl chloride, and lastly heat treatment. It was concluded that heat treatment is one of the most suitable treatment methods for enhancing mechanical properties of jute FRP. Durability studies on Jute FRP pertaining to some common environmental conditions were also carried out such as effect of normal water and thermal aging on the tensile strength of jute FRP followed by fire flow test. The heat treated woven jute FRP composites were subsequently used for flexural strengthening of reinforced concrete beams in full and strip wrapping configurations. The study includes the effect of flexural strengthening provided by woven jute FRP, study of different failure modes, load deflection behavior, effect on the first crack load, and ultimate flexural strength of concrete beams strengthened using woven jute FRP subjected to bending loads. The study concludes that woven jute FRP is a suitable material which can be used for flexural upgradation of reinforced concrete beams.

  15. The cyanobacterial Fluorescence Recovery Protein has two distinct activities: Orange Carotenoid Protein amino acids involved in FRP interaction.

    Science.gov (United States)

    Thurotte, Adrien; Bourcier de Carbon, Céline; Wilson, Adjélé; Talbot, Léa; Cot, Sandrine; López-Igual, Rocio; Kirilovsky, Diana

    2017-04-01

    To deal with fluctuating light condition, cyanobacteria have developed a photoprotective mechanism which, under high light conditions, decreases the energy arriving at the photochemical centers. It relies on a photoswitch, the Orange Carotenoid Protein (OCP). Once photoactivated, OCP binds to the light harvesting antenna, the phycobilisome (PBS), and triggers the thermal dissipation of the excess energy absorbed. Deactivation of the photoprotective mechanism requires the intervention of a third partner, the Fluorescence Recovery Protein (FRP). FRP by interacting with the photoactivated OCP accelerates its conversion to the non-active form and its detachment from the phycobilisome. We have studied the interaction of FRP with free and phycobilisome-bound OCP. Several OCP variants were constructed and characterized. In this article we show that OCP amino acid F299 is essential and D220 important for OCP deactivation mediated by FRP. Mutations of these amino acids did not affect FRP activity as helper to detach OCP from phycobilisomes. In addition, while mutated R60L FRP is inactive on OCP deactivation, its activity on the detachment of the OCP from the phycobilisomes is not affected. Thus, our results demonstrate that FRP has two distinct activities: it accelerates OCP detachment from phycobilisomes and then it helps deactivation of the OCP. They also suggest that different OCP and FRP amino acids could be involved in these two activities.

  16. 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.

  17. 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.

  18. 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...

  19. Crack-induced debonding failure in fiber reinforced plastics (FRP) strengthened concrete beams: Experimental and theoretical analysis

    Science.gov (United States)

    Pan, Jinlong

    External bonding of FRP plates to the tension substrate of RC beams has been accepted as an efficient and effective technique for flexural strengthening. In this thesis, different problems related to crack-induced debonding of the FRP plate in the flexural strengthened concrete beams have been investigated. FRP strengthened RC beam may fail by FRP debonding from the bottom of a major flexural crack in the span. This kind of failure is studied with the direct shear test in the present research work. Our experimental investigation focuses on the effect of concrete composition on the bond behavior between FRP and concrete. Based on the test results, the bond capacity of the specimen is found to be governed by the concrete surface tensile strength, aggregate size and aggregate content. Then, the neural network is employed to derive an empirical expression for the interfacial fracture energy in terms of concrete surface tensile strength and aggregate content. Using the empirical equation, simulated bond capacity is in good agreement with experimental results. In the FRP strengthened RC beams, debonding of the FRP plate often occurs under the presence of multiple cracks along the span. In the present thesis, experimental and theoretical investigations are performed to study the effect of multiple secondary cracks on the debonding behavior and ultimate load capacity. A new analytical model for FRP debonding under multiple cracks has been developed. The effect of the multiple secondary cracks on the shear softening in the debonded zone is explicitly considered in the model. Using the new model, the simulated values of ultimate load when debonding occurs are in good agreement with measured values. In the FRP strengthened RC beams, concrete cover separation or plate end debonding can be avoided by applying tapers at the FRP plate end. In this situation, it is easier for FRP debonding to be induced by a major flexural crack close to the support. To study the effect of the

  20. An Experimental Simulation to Validate FEM to Predict Transverse Young’s Modulus of FRP Composites

    Directory of Open Access Journals (Sweden)

    V. S. Sai

    2013-01-01

    Full Text Available Finite element method finds application in the analysis of FRP composites due to its versatility in getting the solution for complex cases which are not possible by exact classical analytical approaches. The finite element result is questionable unless it is obtained from converged mesh and properly validated. In the present work specimens are prepared with metallic materials so that the arrangement of fibers is close to hexagonal packing in a matrix as similar arrangement in case of FRP is complex due to the size of fibers. Transverse Young’s moduli of these specimens are determined experimentally. Equivalent FE models are designed and corresponding transverse Young’s moduli are compared with the experimental results. It is observed that the FE values are in good agreement with the experimental results, thus validating FEM for predicting transverse modulus of FRP composites.

  1. Constitutive Behavior and Finite Element Analysis of FRP Composite and Concrete Members

    Directory of Open Access Journals (Sweden)

    Ki Yong Ann

    2013-09-01

    Full Text Available The present study concerns compressive and flexural constitutive models incorporated into an isoparametric beam finite element scheme for fiber reinforced polymer (FRP and concrete composites, using their multi-axial constitutive behavior. The constitutive behavior of concrete was treated in triaxial stress states as an orthotropic hypoelasticity-based formulation to determine the confinement effect of concrete from a three-dimensional failure surface in triaxial stress states. The constitutive behavior of the FRP composite was formulated from the two-dimensional classical lamination theory. To predict the flexural behavior of circular cross-section with FRP sheet and concrete composite, a layered discretization of cross-sections was incorporated into nonlinear isoparametric beam finite elements. The predicted constitutive behavior was validated by a comparison to available experimental results in the compressive and flexural beam loading test.

  2. Novel hybrid FRP tubular columns for sustainable mining infrastructure:Recent research at University of Wollongong

    Institute of Scientific and Technical Information of China (English)

    Yu Tao; Remennikov Alex M.

    2014-01-01

    This paper introduces, for applications in the mining industry, an innovative hybrid column form which consists of an inner steel tube, an outer fibre-reinforced polymer (FRP) tube and an annular concrete infill between them. The two tubes may be concentrically placed to produce a section form more suitable for columns, or eccentrically placed to produce a section form more suitable for beams. The FRP is combined with steel and concrete in these hybrid structural members in such a way that the advantages of FRP are appropriately exploited while its disadvantages are minimized. As a result, these hybrid members pos-sess excellent corrosion resistance as well as excellent ductility and seismic resistance. This paper sum-marizes existing research on this new form of structural members, and discusses their potential applications in mining infrastructure before presenting a summary of the recent and current studies at University of Wollongong (UOW) on their structural behaviour and design.

  3. An experimentally based analytical model for the shear capacity of FRP-strengthened reinforced concrete beams

    Science.gov (United States)

    Pellegrino, C.; Modena, C.

    2008-05-01

    This paper deals with the shear strengthening of Reinforced Concrete (RC) flexural members with externally bonded Fiber-Reinforced Polymers (FRPs). The interaction between an external FRP and an internal transverse steel reinforcement is not considered in actual code recommendations, but it strongly influences the efficiency of the shear strengthening rehabilitation technique and, as a consequence, the computation of interacting contributions to the nominal shear strength of beams. This circumstance is also discussed on the basis of the results of an experimental investigation of rectangular RC beams strengthened in shear with "U-jacketed" carbon FRP sheets. Based on experimental results of the present and other investigations, a new analytical model for describing the shear capacity of RC beams strengthened according to the most common schemes (side-bonded and "U-jacketed"), taking into account the interaction between steel and FRP shear strength contributions, is proposed.

  4. 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...

  5. 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.

  6. 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...

  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. 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.

  9. 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...

  10. 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.

  11. 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...

  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. 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

  14. Nucleotide variation of sFRP5 gene is not associated with obesity in children and adolescents.

    Science.gov (United States)

    Van Camp, Jasmijn K; Beckers, Sigri; Zegers, Doreen; Verhulst, Stijn L; Van Hoorenbeeck, Kim; Massa, Guy; Verrijken, An; Desager, Kristine N; Van Gaal, Luc F; Van Hul, Wim

    2016-10-01

    Because sFRP5 was shown to be an important extracellular modulator of the Wnt pathway, regulating adipogenesis, we wanted to investigate the role of sFRP5 variants in human, monogenic obesity by performing mutation analysis. We screened the complete sFRP5 coding region in 622 obese children and adolescents and 503 lean control individuals by high-resolution melting curve analysis and direct sequencing. We found a total of 15 sequence variants in sFRP5, 10 of which resulted in a non-synonymous amino acid change. Five of these variants were, to our knowledge, not previously reported. For one of the variants (c.-3G>A), we identified a trend towards association between the variant frequency and the obese phenotype. We argue that, when looking at conservation and location inside known protein domains, several of the identified variants (D103N, A113V, K212N and H317L), may affect sFRP5 protein function. In addition, we found c.-3G>A, residing in the Kozak sequence, with a lower frequency in cases compared to controls. However, functional studies investigating the effect of sFRP5 variants on protein function are necessary to determine the true role of sFRP5 genetic variation in human, monogenic obesity.

  15. Mechanical Behaviour and Durability of FRP-to-steel Adhesively-bonded Joints

    NARCIS (Netherlands)

    Jiang, X.

    2013-01-01

    During the last two decades, fiber-reinforced polymer (FRP) bridge decks have been increasingly used as a competitive alternative for wood, concrete and orthotropic steel decks, due to their various advantages: light-weight, good corrosion resistance, low maintenance cost and rapid installation for

  16. In-situ monitoring of curing and ageing effects in FRP plates using embedded FBG sensors

    Science.gov (United States)

    Xian, Guijun; Wang, Chuan; Li, Hui

    2010-04-01

    In recent years, fiber reinforced polymer (FRP) composites have been widely applied in civil engineering for retrofitting or renewal of existing structures. Since FRP composite may degrade when exposed to severe outdoor environments, a serious concern has been raised on its long term durability. In the present study, fiber Bragg grating (FBG) sensors were embedded in glass-, carbon- and basalt-fiber reinforced epoxy based FRP plates with wet lay-up technology, to in-situ monitor the stain changes in FRPs during the curing, and water immersion and freeze-thaw ageing processes. The study demonstrates that the curing of epoxy resin brings in a slight tension strain (e.g., 10 ~ 30 μɛ) along the fiber direction and a high contraction (e.g., ~ 1100μɛ) in the direction perpendicular to the fibers, mainly due to the resin shrinkage. The cured FRP strips were then subjected to distilled water immersion at 80oC and freeze-thaw cycles from -30°C to 30°C. Remarkable strain changes of FRPs due to the variation of the temperatures during freeze-thaw cycles indicate the potential property degradation from fatigue. The maximum strain change is dependent on the fiber types and directions to the fiber. Based on the monitored strain values with temperature change and water uptake content, CTE (coefficient of thermal expansion) and CME (coefficient of moisture expansion) are exactly determined for the FRPs.

  17. Mechanical properties and aesthetics of FRP orthodontic wire fabricated by hot drawing.

    Science.gov (United States)

    Imai, T; Watari, F; Yamagata, S; Kobayashi, M; Nagayama, K; Toyoizumi, Y; Nakamura, S

    1998-12-01

    The FRP wires 0.5 mm in diameter with a multiple fiber structure were fabricated by drawing the fiber polymer complex at 250 degrees C for an esthetic, transparent orthodontic wire. Biocompatible CaO-P2O5-SiO2-Al2O3 (CPSA) glass fibers of 8-20 microm in diameter were oriented unidirectionally in the longitudinal direction in PMMA matrix. The mechanical properties were investigated by 3-point flexural test. The FRP wire showed sufficient strength and a very good elastic recovery after deformation. Young's modulus and the flexural load at deflection 1 mm were nearly independent of the fiber diameter and linearly increased with the fiber fraction. The dependence on fiber fraction obeys well the rule of mixture. This FRP wire could cover the range of strength corresponding to the conventional metal orthodontic wires from Ni-Ti used in the initial stage of orthodontic treatments to Co-Cr used in the final stage by changing the volume ratio of glass fibers with the same external diameter. The estheticity in external appearance was excellent. Thus the new FRP wire can satisfy both mechanical properties necessary for an orthodontic wire and enough estheticity, which was not possible for the conventional metal wire.

  18. Reliability model for ductile hybrid FRP rebar using randomly dispersed chopped fibers

    Science.gov (United States)

    Behnam, Bashar Ramzi

    Fiber reinforced polymer composites or simply FRP composites have become more attractive to civil engineers in the last two decades due to their unique mechanical properties. However, there are many obstacles such as low elasticity modulus, non-ductile behavior, high cost of the fibers, high manufacturing costs, and absence of rigorous characterization of the uncertainties of the mechanical properties that restrict the use of these composites. However, when FRP composites are used to develop reinforcing rebars in concrete structural members to replace the conventional steel, a huge benefit can be achieved since FRP materials don't corrode. Two FRP rebar models are proposed that make use of multiple types of fibers to achieve ductility, and chopped fibers are used to reduce the manufacturing costs. In order to reach the most optimum fractional volume of each type of fiber, to minimize the cost of the proposed rebars, and to achieve a safe design by considering uncertainties in the materials and geometry of sections, appropriate material resistance factors have been developed, and a Reliability Based Design Optimization (RBDO), has been conducted for the proposed schemes.

  19. LSA SAF Meteosat FRP Products: Part 2 - Evaluation and demonstration of use in the Copernicus Atmosphere Monitoring Service (CAMS)

    Science.gov (United States)

    Roberts, G.; Wooster, M. J.; Xu, W.; Freeborn, P. H.; Morcrette, J.-J.; Jones, L.; Benedetti, A.; Kaiser, J.

    2015-06-01

    Characterising the dynamics of landscape scale wildfires at very high temporal resolutions is best achieved using observations from Earth Observation (EO) sensors mounted onboard geostationary satellites. As a result, a number of operational active fire products have been developed from the data of such sensors. An example of which are the Fire Radiative Power (FRP) products, the FRP-PIXEL and FRP-GRID products, generated by the Land Surface Analysis Satellite Applications Facility (LSA SAF) from imagery collected by the Spinning Enhanced Visible and Infrared Imager (SEVIRI) on-board the Meteosat Second Generation (MSG) series of geostationary EO satellites. The processing chain developed to deliver these FRP products detects SEVIRI pixels containing actively burning fires and characterises their FRP output across four geographic regions covering Europe, part of South America and northern and southern Africa. The FRP-PIXEL product contains the highest spatial and temporal resolution FRP dataset, whilst the FRP-GRID product contains a spatio-temporal summary that includes bias adjustments for cloud cover and the non-detection of low FRP fire pixels. Here we evaluate these two products against active fire data collected by the Moderate Resolution Imaging Spectroradiometer (MODIS), and compare the results to those for three alternative active fire products derived from SEVIRI imagery. The FRP-PIXEL product is shown to detect a substantially greater number of active fire pixels than do alternative SEVIRI-based products, and comparison to MODIS on a per-fire basis indicates a strong agreement and low bias in terms of FRP values. However, low FRP fire pixels remain undetected by SEVIRI, with errors of active fire pixel detection commission and omission compared to MODIS ranging between 9-13 and 65-77% respectively in Africa. Higher errors of omission result in greater underestimation of regional FRP totals relative to those derived from simultaneously collected MODIS

  20. LSA SAF Meteosat FRP products - Part 2: Evaluation and demonstration for use in the Copernicus Atmosphere Monitoring Service (CAMS)

    Science.gov (United States)

    Roberts, G.; Wooster, M. J.; Xu, W.; Freeborn, P. H.; Morcrette, J.-J.; Jones, L.; Benedetti, A.; Jiangping, H.; Fisher, D.; Kaiser, J. W.

    2015-11-01

    Characterising the dynamics of landscape-scale wildfires at very high temporal resolutions is best achieved using observations from Earth Observation (EO) sensors mounted onboard geostationary satellites. As a result, a number of operational active fire products have been developed from the data of such sensors. An example of which are the Fire Radiative Power (FRP) products, the FRP-PIXEL and FRP-GRID products, generated by the Land Surface Analysis Satellite Applications Facility (LSA SAF) from imagery collected by the Spinning Enhanced Visible and Infrared Imager (SEVIRI) onboard the Meteosat Second Generation (MSG) series of geostationary EO satellites. The processing chain developed to deliver these FRP products detects SEVIRI pixels containing actively burning fires and characterises their FRP output across four geographic regions covering Europe, part of South America and Northern and Southern Africa. The FRP-PIXEL product contains the highest spatial and temporal resolution FRP data set, whilst the FRP-GRID product contains a spatio-temporal summary that includes bias adjustments for cloud cover and the non-detection of low FRP fire pixels. Here we evaluate these two products against active fire data collected by the Moderate Resolution Imaging Spectroradiometer (MODIS) and compare the results to those for three alternative active fire products derived from SEVIRI imagery. The FRP-PIXEL product is shown to detect a substantially greater number of active fire pixels than do alternative SEVIRI-based products, and comparison to MODIS on a per-fire basis indicates a strong agreement and low bias in terms of FRP values. However, low FRP fire pixels remain undetected by SEVIRI, with errors of active fire pixel detection commission and omission compared to MODIS ranging between 9-13 % and 65-77 % respectively in Africa. Higher errors of omission result in greater underestimation of regional FRP totals relative to those derived from simultaneously collected MODIS

  1. LSA SAF Meteosat FRP Products: Part 2 – Evaluation and demonstration of use in the Copernicus Atmosphere Monitoring Service (CAMS

    Directory of Open Access Journals (Sweden)

    G. Roberts

    2015-06-01

    Full Text Available Characterising the dynamics of landscape scale wildfires at very high temporal resolutions is best achieved using observations from Earth Observation (EO sensors mounted onboard geostationary satellites. As a result, a number of operational active fire products have been developed from the data of such sensors. An example of which are the Fire Radiative Power (FRP products, the FRP-PIXEL and FRP-GRID products, generated by the Land Surface Analysis Satellite Applications Facility (LSA SAF from imagery collected by the Spinning Enhanced Visible and Infrared Imager (SEVIRI on-board the Meteosat Second Generation (MSG series of geostationary EO satellites. The processing chain developed to deliver these FRP products detects SEVIRI pixels containing actively burning fires and characterises their FRP output across four geographic regions covering Europe, part of South America and northern and southern Africa. The FRP-PIXEL product contains the highest spatial and temporal resolution FRP dataset, whilst the FRP-GRID product contains a spatio-temporal summary that includes bias adjustments for cloud cover and the non-detection of low FRP fire pixels. Here we evaluate these two products against active fire data collected by the Moderate Resolution Imaging Spectroradiometer (MODIS, and compare the results to those for three alternative active fire products derived from SEVIRI imagery. The FRP-PIXEL product is shown to detect a substantially greater number of active fire pixels than do alternative SEVIRI-based products, and comparison to MODIS on a per-fire basis indicates a strong agreement and low bias in terms of FRP values. However, low FRP fire pixels remain undetected by SEVIRI, with errors of active fire pixel detection commission and omission compared to MODIS ranging between 9–13 and 65–77% respectively in Africa. Higher errors of omission result in greater underestimation of regional FRP totals relative to those derived from simultaneously

  2. 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.

  3. 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...

  4. 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.

  5. 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.

  6. 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.

  7. 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 ...

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 装配式FRP筋混凝土节点研究%Prefabricated FRP Tendons Concrete Node Research

    Institute of Scientific and Technical Information of China (English)

    刘志威

    2016-01-01

    为了解决钢筋锈蚀的问题,研究人员提出采用 FRP 筋来替代钢筋使用到腐蚀环境中。由于 FRP 筋成型之后无法进行焊接和机械加工,文中提出在使用 FRP 筋混凝土时采用装配式的结构形式进行施工,之后对装配式FRP筋混凝土节点进行设计,再通过有限元模拟分析节点的力学性能。%In the island of engineering structure,reinforcement corrosion is a major problem affecting the safety of structure.In order to solve this problem,researchers put forward using FRP reinforcement to replace the steel used in corrosion environment.The FRP material is a thermosetting material,the anisotropy is serious,so it can not be welded and mechanical processing,so the assembly structure will be more convenient.This paper mainly puts forward the structure form of FRP reinforced concrete node,through the finite element simulation analysis of mechanical properties of the node.

  13. 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.

  14. 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.

  15. Barras de FRP: avaliando o módulo de elasticidade não destrutivamente FRP bars: assesing elastic modulus nondestructively

    Directory of Open Access Journals (Sweden)

    Protasio F Castro

    1997-06-01

    Full Text Available Um estudo experimental foi realizado com o objetivo de contribuir com o desenvolvimento de métodos de ensaios de avaliação das características mecânicas das barras de plástico reforçado com fibra (FRP a serem utilizadas como armadura nas obras de engenharia civil. Comparou-se o módulo de elasticidade estático, obtido por ensaio de tração em uma máquina universal, com o módulo de elasticidade dinâmico, obtido por ensaios não destrutivos. O módulo de elasticidade dinâmico foi determinado utilizando-se dois métodos de propagação de ondas: o pulso ultra-sônico e a freqüência de ressonância. Os valores do módulo de elasticidade dinâmico e os valores do módulo de elasticidade estático obtidos a partir da curva tensão-deformação dos ensaios de tração são significativamente semelhantes. Os resultados mostram que os ensaios de módulo de elasticidade dinâmico possuem potencial para serem utilizados na linha de fabricação das barras de FRP como controle da produção.An experimental study was carried out to support the development of standards test methods for fiber reinforced plastic (FRP bars used as concrete reinforcement. In addition, this study compares the elastic modulus values from tensile stress-strain curves with the dynamic values obtained nondestructively. Dynamic modulus of elasticity was determined using two stress wave propagation methods: ultrasonic pulse velocity and resonant frequency. The dynamic values compared favorably with values obtained from tensile stress-strain curves. The results showed the feasibility of using nondestructive methods, as control test, to estimate FRP bars elastic modulus in a manufacture process.

  16. FRP-钢管-混凝土构件抗震性能试验研究%Experimental study on seismic property of concrete filled FRP- steel tube

    Institute of Scientific and Technical Information of China (English)

    朱春阳; 赵颖华; 李晓飞

    2013-01-01

    The same size specimens strengthened by FRP (CFRP/GFRP) sheets with different wrapping modes were studied experimentally by quasi-static test system for the purpose of investigating the mechanical property of concrete filled GFRP - steel tube structure under combined seismic loading and comparing it with concrete filled CFRP steel tube. Combined loads including axial pressure and bending were applied to simulate the complex seismic loadings. The test results indicate that the strengthening of FRP (CFRP/GFRP) is potential and effective for significant improvements in dynamic bending resistance of the structures. Concrete filled GFRP - steel tube equips higher ductility, comparing with concrete filled steel tube, energy dissipation coefficient of the components with circumferential, longitudinal and bi - directional GFRP improve 2.0%, 7.0% and 12. 7% respectively, while components with circumferential, longitudinal and bi-directional CFRP get improvement of 2. 0% , 5. 8% and 6. 7% respectively.%为了研究低周循环往复荷载作用下GFRP(glass fiber reinforced polymer)-钢管-混凝构件的力学性能以及对比CFRP(carbon fiber reinforced polymer)-钢管-混凝土构件的性能差异,对尺寸相同而加固方式不同的圆形截面FRP(GFRP、CFRP)-钢管-混凝土试件进行了拟静力试验,荷载采用轴压、双向弯曲的组合来模拟地震动力.结果表明:FRP(GFRP、CFRP)的加固可以有效地提高构件抗动态弯曲的能力;GFRP-钢管-混凝土构件延性高于相同情况下CFRP -钢管-混凝土构件;与普通钢管-混凝土相比,环向、纵向和双向包裹的GFRP-钢管-混凝土构件的耗能系数分别提高2.0%、7.0%和12.7%,而CFRP-钢管-混凝土分别提高2.0%、5.8%和6.7%.

  17. 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.

  18. Utilisation of fibre reinforced polymer (FRP) composites in the confinement of concrete

    OpenAIRE

    Ciupala, Mihaela Anca; Pilakoutas, K.; Mortazavi, A.A.

    2007-01-01

    This paper presents an experimental investigation carried out on concrete cylinders\\ud confined with fibre reinforced polymers (FRP), subjected to monotonic and cyclic loading.\\ud Carbon fibres (CFRP) were used as confining material for the concrete specimens. The failure\\ud mode, reinforcement ratio based on jacket thickness and type of loading are examined. The study\\ud shows that external confinement of concrete can enhance its strength and ductility as well as result\\ud in large energy ab...

  19. Effect of adhesive thickness and concrete strength on FRP-Concrete Bonds

    OpenAIRE

    López González, Julio César; Fernandez Gomez, Jaime Antonio; González Valle, Enrique

    2012-01-01

    The use of fiber-reinforced polymer (FRP) composites for strengthening, repairing, or rehabilitating concrete structures has become more and more popular in the last 10 years. Irrespective of the type of strengthening used, design is conditioned, among others, by concrete-composite bond failure, normally attributed to stress at the interface between these two materials. Single shear, double shear, and notched beam tests are the bond tests most commonly used by the scientific community to esti...

  20. Combined Transverse Steel-External FRP Confinement Model for Rectangular Reinforced Concrete Columns

    Directory of Open Access Journals (Sweden)

    Ahmed Al-Rahmani

    2016-02-01

    Full Text Available Recently, the need to increase the strength of reinforced concrete members has become a subject that civil engineers are interested in tackling. Of the many proposed solutions, fiber-reinforced polymer (FRP materials have attracted attention due to their superior properties, such as high strength-to-weight ratio, high energy absorption and excellent corrosion resistance. FRP wrapping of concrete columns is done to enhance the ultimate strength due to the confinement effect, which is normally induced by steel ties. The existence of the two confinement systems changes the nature of the problem, thus necessitating specialized nonlinear analysis to obtain the column’s ultimate capacity. Existing research focused on a single confinement system. Furthermore, very limited research on rectangular sections was found in the literature. In this work, a model to estimate the combined behavior of the two systems in rectangular columns is proposed. The calculation of the effective lateral pressure is based on the Lam and Teng model and the Mander model for FRP wraps and steel ties, respectively. The model then generates stress-strain diagrams for both the concrete core and the cover. The model was developed for the analysis in extreme load events, where all possible contributions to the column’s ultimate capacity should be accounted for without any margin of safety. The model was validated against experiments, and the results obtained showed good agreement with almost all of the available experimental data.

  1. THEORETICAL MODEL ON INTERFACE FAILURE MECHANISM OF REINFORCED CONCRETE CONTINUOUS BEAM STRENGTHENED BY FRP

    Institute of Scientific and Technical Information of China (English)

    Hong Yuan; Zifeng Lin

    2009-01-01

    Fiber reinforced polymer (FRP) composites are increasingly being used for the re-pair and strengthening of deteriorated concrete structural components through adhesive bonding of prefabricated strips/plates and the wet lay-up of fabric. Interracial bond failure modes have at-tracted the attention of researchers because of the importance. The objective of the present study is to analyse the interface failure mechanism of reinforced concrete continuous beam strength-ened by FRP. An analytical solution has been firstly presented to predict the entire debonding process of the model. The realistic bi-linear bond-slip interfacial law was adopted to study this problem. The crack propagation process of the loaded model was divided into four stages (elastic, elastic-softening, elastic-softening-debonded and softening-debonded stage). Among them, elastic-softening-debonded stage has four sub-stages. The equations are solved by adding suitable stress and displacement boundary conditions. Finally, critical value of bond length is determined to make the failure mechanism in the paper effective by solving the simultaneously linear algebraic equations. The interaction between the upper and lower FRP plates can be neglected if axial stiffness ratio of the concrete-to-plate prism is large enough.

  2. Strength Modeling of Reinforced Concrete Beam with Externally Bonded FRP Reinforcement

    Directory of Open Access Journals (Sweden)

    N. Pannirselvam

    2008-01-01

    Full Text Available This research study presents the evaluation of the structural behaviour of reinforced concrete beams with externally bonded Fibre Reinforced Polymer (FRP reinforcements. Three different steel ratios with two different Glass Fibre Reinforced Polymer (GFRP types and two different thicknesses in each type of GFRP were used. Totally fifteen rectangular beams of 3 m length were cast. Three rectangular beams were used as reference beam (Control Beams and the remaining were fixed with GFRP laminates on the soffit of the rectangular beam. The variables considered for the study includes longitudinal steel ratio, type of GFRP laminates, thickness of GFRP laminates and composite ratios. Flexural test, using simple beam with third-point loading was adopted to study the performance of FRP plated beams interms flexural strength, deflection, ductility and was compared with the unplated beams. The test results show that the beams strengthened with GFRP laminates exhibit better performance. The flexural strength and ductility increase with increase in thickness of GFRP plate. The increase in first crack loads was up to 88.89% for 3 mm thick WRGFRP plates and 100.00% for 5 mm WRGFRP plated beams and increase in ductility interms of energy and deflection was found to be 56.01 and 64.69% respectively with 5 mm thick GFRP plated beam. Strength models were developed for predicting the flexural strength (ultimate load, service load and ductility of FRP beams. The strength model developed give prediction matching the measurements.

  3. Disbond detection with piezoelectric wafer active sensors in RC structures strengthened with FRP composite overlays

    Institute of Scientific and Technical Information of China (English)

    Victor Giurgiutiu; Kent Harries; Michael Petrou; Joel Bost; Josh B. Quattlebaum

    2003-01-01

    The capability of embedded piezoelectric wafer active sensors (PWAS) to perform in-situ nondestructive evaluation (NDE) for structural health monitoring (SHM) of reinforced concrete (RC) structures strengthened with fiber reinforced polymer (FRP) composite overlays is explored. First, the disbond detection method were developed on coupon specimens consisting of concrete blocks covered with an FRP composite layer. It was found that the prescnce of a disbond crack drastically changes the electromecbanical (E/M) impedance spectrum measured at the PWAS terminals. The spectral changes depend on the distance between the PWAS and the crack tip. Second, large scale experiments were conducted on a RC beam strengthened with carbon fiber reinforced polymer (CFRP) composite overlay. The beam was subject to an acccleratcd fatigue load regime in a three-point bending configuration up to a total of807,415 cycles. During these fatigue tests, the CFRP overlay experienced disbonding beginning at about 500,000 cycles. The PWAS were able to detect the disbonding before it could be reliably seen by visual inspection. Good correlation between the PWAS readings and the position and extent of disbond damage was observed. These preliminary results demonstrate the potential of PWAS technology for SHM of RC structures strengthened with FRP composite ovcrlays.

  4. Experimental Study on Bond Behavior of FRP-Concrete Interface in Hygrothermal Environment

    Directory of Open Access Journals (Sweden)

    X. H. Zheng

    2016-01-01

    Full Text Available As the technique of fiber-reinforced polymer (FRP composite material strengthened reinforced concrete structures is widely used in the field of civil engineering, durability of the strengthened structures has attracted more attention in recent years. Hygrothermal environment has an adverse effect on the bond behavior of the interface between FRP and concrete. This paper focuses on the bond durability of carbon fiber laminate- (CFL- concrete interface in hygrothermal condition which simulates the climate characteristic in South China. Twenty 100 mm × 100 mm × 720 mm specimens were divided into 6 groups based on different temperature and humidity. After pretreatment in hygrothermal environment, the specimens were tested using double shear method. Strain gauges bonded along the CFL surface and linear variation displacement transducers (LVDTs were used to measure longitudinal strains and slip of the interface. Failure mode, ultimate capacity, load-deflection relationship, and relative slip were analyzed. The bond behavior of FRP-concrete interface under hygrothermal environment was studied. Results show that the ultimate bearing capacity of the interface reduced after exposure to hygrothermal environments. The decreasing ranges were up to 27.9% after exposure at high temperature and humidity (60°C, 95% RH. The maximum strains (εmax of the specimens pretreated decreased obviously which indicated decay of the bond behavior after exposure to the hygrothermal environment.

  5. A state of the art review on reinforced concrete beams with openings retrofitted with FRP

    Science.gov (United States)

    Osman, Bashir H.; Wu, Erjun; Ji, Bohai; S Abdelgader, Abdeldime M.

    2016-09-01

    The use of externally bonded fiber reinforced polymer (FRP) sheets, strips or steel plates is a modern and convenient way for strengthening of reinforced concrete (RC) beams. Several researches have been carried out on reinforced concrete beams with web openings that strengthened using fiber reinforced polymer composite. Majority of researches focused on shear strengthening compared with flexural strengthening, while others studied the effect of openings on shear and flexural separately with various loading. This paper investigates the impact of more than sixty articles on opening reinforced concrete beams with and without strengthening by fiber reinforcement polymers FRP. Moreover, important practical issues, which are contributed in shear strengthening of beams with different strengthening techniques, such as steel plate and FRP laminate, and detailed with various design approaches are discussed. Furthermore, a simple technique of applying fiber reinforced polymer contributed with steel plate for strengthening the RC beams with openings under different load application is concluded. Directions for future research based on the existing gaps of the present works are presented.

  6. 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.

  7. 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...

  8. Diabetic osteopenia by decreased β-catenin signaling is partly induced by epigenetic derepression of sFRP-4 gene.

    Directory of Open Access Journals (Sweden)

    Kiyoshi Mori

    Full Text Available In diabetics, methylglyoxal (MG, a glucose-derived metabolite, plays a noxious role by inducing oxidative stress, which causes and exacerbates a series of complications including low-turnover osteoporosis. In the present study, while MG treatment of mouse bone marrow stroma-derived ST2 cells rapidly suppressed the expression of osteotrophic Wnt-targeted genes, including that of osteoprotegerin (OPG, a decoy receptor of the receptor activator of NF-kappaB ligand (RANKL, it significantly enhanced that of secreted Frizzled-related protein 4 (sFRP-4, a soluble inhibitor of Wnts. On the assumption that upregulated sFRP-4 is a trigger that downregulates Wnt-related genes, we sought out the molecular mechanism whereby oxidative stress enhanced the sFRP-4 gene. Sodium bisulfite sequencing revealed that the sFRP-4 gene was highly methylated around the sFRP-4 gene basic promoter region, but was not altered by MG treatment. Electrophoretic gel motility shift assay showed that two continuous CpG loci located five bases upstream of the TATA-box were, when methylated, a target of methyl CpG binding protein 2 (MeCP2 that was sequestered upon induction of 8-hydroxy-2-deoxyguanosine, a biomarker of oxidative damage to DNA. These in vitro data suggest that MG-derived oxidative stress (not CpG demethylation epigenetically and rapidly derepress sFRP-4 gene expression. We speculate that under persistent oxidative stress, as in diabetes and during aging, osteopenia and ultimately low-turnover osteoporosis become evident partly due to osteoblastic inactivation by suppressed Wnt signaling of mainly canonical pathways through the derepression of sFRP-4 gene expression.

  9. Trapezoidal Numerical Integration of Fire Radiative Power (FRP) Provides More Reliable Estimation of Fire Radiative Energy (FRE) and so Biomass Consumption Than Conventional Estimation Methods

    Science.gov (United States)

    Sathyachandran, S. K.; Roy, D. P.; Boschetti, L.

    2014-12-01

    The Fire Radiative Power (FRP) [MW] is a measure of the rate of biomass combustion and can be retrieved from ground based and satellite observations using middle infra-red measurements. The temporal integral of FRP is the Fire Radiative Energy (FRE) [MJ] and is related linearly to the total biomass consumption and so pyrogenic emissions. Satellite derived biomass consumption and emissions estimates have been derived conventionally by computing the summed total FRP, or the average FRP (arithmetic average of FRP retrievals), over spatial geographic grids for fixed time periods. These two methods are prone to estimation bias, especially under irregular sampling conditions such as provided by polar-orbiting satellites, because the FRP can vary rapidly in space and time as a function of the fire behavior. Linear temporal integration of FRP taking into account when the FRP values were observed and using the trapezoidal rule for numerical integration has been suggested as an alternate FRE estimation method. In this study FRP data measured rapidly with a dual-band radiometer over eight prescribed fires are used to compute eight FRE values using the sum, mean and trapezoidal estimation approaches under a variety of simulated irregular sampling conditions. The estimated values are compared to biomass consumed measurements for each of the eight fires to provide insights into which method provides more accurate and precise biomass consumption estimates. The three methods are also applied to continental MODIS FRP data to study their differences using polar orbiting satellite data. The research findings indicate that trapezoidal FRP numerical integration provides the most reliable estimator.

  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. 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. 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...

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. A coupled interface-body nonlocal damage model for the analysis of FRP strengthening detachment from cohesive material

    Directory of Open Access Journals (Sweden)

    J. Toti

    2011-10-01

    Full Text Available In the present work, a new model of the FRP-concrete or masonry interface, which accounts for the coupling occurring between the degradation of the cohesive material and the FRP detachment, is presented; in particular, a coupled interface-body nonlocal damage model is proposed. A nonlocal damage and plasticity model is developed for the quasi-brittle material. For the interface, a model which accounts for the mode I, mode II and mixed mode of damage and for the unilateral contact and friction effects is developed. Two different ways of performing the coupling between the body damage and the interface damage are proposed and compared. Some numerical applications are carried out in order to assess the performances of the proposed model in reproducing the mechanical behavior of the masonry elements strengthened with external FRP reinforcements.

  19. Use of a molecular decoy to segregate transport from antigenicity in the FrpB iron transporter from Neisseria meningitidis.

    Directory of Open Access Journals (Sweden)

    Muhammad Saleem

    Full Text Available FrpB is an outer membrane transporter from Neisseria meningitidis, the causative agent of meningococcal meningitis. It is a member of the TonB-dependent transporter (TBDT family and is responsible for iron uptake into the periplasm. FrpB is subject to a high degree of antigenic variation, principally through a region of hypervariable sequence exposed at the cell surface. From the crystal structures of two FrpB antigenic variants, we identify a bound ferric ion within the structure which induces structural changes on binding which are consistent with it being the transported substrate. Binding experiments, followed by elemental analysis, verified that FrpB binds Fe(3+ with high affinity. EPR spectra of the bound Fe(3+ ion confirmed that its chemical environment was consistent with that observed in the crystal structure. Fe(3+ binding was reduced or abolished on mutation of the Fe(3+-chelating residues. FrpB orthologs were identified in other Gram-negative bacteria which showed absolute conservation of the coordinating residues, suggesting the existence of a specific TBDT sub-family dedicated to the transport of Fe(3+. The region of antigenic hypervariability lies in a separate, external sub-domain, whose structure is conserved in both the F3-3 and F5-1 variants, despite their sequence divergence. We conclude that the antigenic sub-domain has arisen separately as a result of immune selection pressure to distract the immune response from the primary transport function. This would enable FrpB to function as a transporter independently of antibody binding, by using the antigenic sub-domain as a 'molecular decoy' to distract immune surveillance.

  20. 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.

  1. 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.

  2. Strengthening of reinforced concrete beams with basalt-based FRP sheets: An analytical assessment

    Science.gov (United States)

    Nerilli, Francesca; Vairo, Giuseppe

    2016-06-01

    In this paper the effectiveness of the flexural strengthening of RC beams through basalt fiber-reinforced sheets is investigated. The non-linear flexural response of RC beams strengthened with FRP composites applied at the traction side is described via an analytical formulation. Validation results and some comparative analyses confirm soundness and consistency of the proposed approach, and highlight the good mechanical performances (in terms of strength and ductility enhancement of the beam) produced by basalt-based reinforcements in comparison with traditional glass or carbon FRPs.

  3. Mineral-Based Bonding of Carbon FRP to Strengthen Concrete Structures

    DEFF Research Database (Denmark)

    Täljsten, Björn; Blanksvärd, T.

    2007-01-01

    The advantages of fiber-reinforced polymer (FRP) -strengthening have been shown time and again during the last decade. Several thousand structures retrofitted with FRPs exist worldwide. There are various reasons why the retrofit is needed, but it is not uncommon for the demands on the structure...... therefore be strengthened before it can be used. Different methods to retrofit with FRPs also exist, such as bonding of plates or sheets, with their use of epoxy as the bonding agent being the commonality. Epoxy provides very good bond to concrete and is durable and resistant to most environments...

  4. 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.

  5. Nonlinear micromechanics-based finite element analysis of the interfacial behaviour of FRP-strengthened reinforced concrete beams

    Science.gov (United States)

    Abd El Baky, Hussien

    This research work is devoted to theoretical and numerical studies on the flexural behaviour of FRP-strengthened concrete beams. The objectives of this research are to extend and generalize the results of simple experiments, to recommend new design guidelines based on accurate numerical tools, and to enhance our comprehension of the bond performance of such beams. These numerical tools can be exploited to bridge the existing gaps in the development of analysis and modelling approaches that can predict the behaviour of FRP-strengthened concrete beams. The research effort here begins with the formulation of a concrete model and development of FRP/concrete interface constitutive laws, followed by finite element simulations for beams strengthened in flexure. Finally, a statistical analysis is carried out taking the advantage of the aforesaid numerical tools to propose design guidelines. In this dissertation, an alternative incremental formulation of the M4 microplane model is proposed to overcome the computational complexities associated with the original formulation. Through a number of numerical applications, this incremental formulation is shown to be equivalent to the original M4 model. To assess the computational efficiency of the incremental formulation, the "arc-length" numerical technique is also considered and implemented in the original Bazant et al. [2000] M4 formulation. Finally, the M4 microplane concrete model is coded in FORTRAN and implemented as a user-defined subroutine into the commercial software package ADINA, Version 8.4. Then this subroutine is used with the finite element package to analyze various applications involving FRP strengthening. In the first application a nonlinear micromechanics-based finite element analysis is performed to investigate the interfacial behaviour of FRP/concrete joints subjected to direct shear loadings. The intention of this part is to develop a reliable bond--slip model for the FRP/concrete interface. The bond

  6. 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

  7. 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...

  8. 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.

  9. 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%.

  10. 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.

  11. 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.

  12. 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.

  13. Influence of terahertz waves on the penetration in thick FRP composite materials

    Science.gov (United States)

    Im, Kwang-Hee; Hsu, David K.; Chiou, Chien-Ping; Barnard, Daniel J.; Yang, In-Young; Park, Je-Woong

    2014-02-01

    Fiber reinforced plastics (FRP) are increasingly utilized in engineering structures because of their performance and fabrication advantages. With this increased utilization, a technique to gage quality and further characterize the materials would be beneficial. The nondestructive applications for Terahertz (T-ray) methods have also experienced increased utilization for evaluating engineering materials and will be reported on here in applications for the inspection and characterization of FRP materials used in wind energy components. First, refraction and transmission T-ray modes are used to determine the refractive index (n) of a glass fiber reinforced plastic (GFRP) reference sample, and extended for calculating the refractive indices for a sample of GFRP, balsa and epoxy. Additionally, carbon fiber reinforced plastic (CFRP) samples were evaluated with respect to fiber directions versus T-ray electric field polarization direction to evaluate the level of penetration of T-ray energy due to the fiber orientation dependent conductivity of this composite material. Finally, an evaluation of T-ray data was made to evaluate resonance effects, where the resonance frequency was found to agree with that expected from reflections from individual plies in thick GFRP laminates.

  14. ANALISA TEKNIS DAN EKONOMIS PENGGUNAAN COREMAT UNTUK KONSTRUKSI FRP (FIBERGLASS REINFORCED PLASTIC SANDWICH PADA BADAN KAPAL

    Directory of Open Access Journals (Sweden)

    Parlindungan Manik

    2012-02-01

    Full Text Available Planning of ship construction is make its having good effectivity value and efficiency. Composite as materialalternative to changes of steel feedstock and wood has many applied named FRP (fiberglass reinforcedplastics single skin. The weakness of this FRP was heavy construction and requires many production time.Therefore, will be checked comparison between single skin with sandwich constructions for shell.In this research, the way for making composite is hand lay up method with three various thickness of skinthere are : t, t/2, and t/4. To know strength comparison from the various skin of sandwich with single skin,must be test, consist of tensile test.. The result is analyzed then compared by BKI (Biro Klasifikasi Indonesiarules for the fiberglass ship.Based on the result, indicates that optimization skin thickness of sandwich construction applies Corematwhich tensile strength it is equivalent with Single Skin at 2/3t and usage of Sandwich construction causes23,12 % lighter. In economic analyze, advantage from low weight is compensation of addition 23,12 % DWT.Material cost for Sandwich about 11,35% bigger than Single Skin construction.

  15. Deformation behavior of FRP-metal composites locally reinforced with carbon fibers

    Science.gov (United States)

    Scholze, M.; Kolonko, A.; Lindner, T.; Lampke, T.; Helbig, F.

    2016-03-01

    This study investigates variations of hybrid laminates, consisting of one aluminum sheet and a unidirectional glass fiber (GF) reinforced polyamide 6 (PA6) basic structure with partial carbon fiber (CF) reinforcement. To create these heterogeneous FRP laminates, it is necessary to design and produce semi-finished textile-based products. Moreover, a warp knitting machine in conjunction with a warp thread offset unit was used to generate bionic inspired compounds. By the variation of stacking prior to the consolidation process of the hybrid laminate, an oriented CF reinforcement at the top and middle layer of the FRP is realized. In both cases the GFRP layer prevents contact between the aluminum and carbon fibers. In so doing, the high strength of carbon fibers can be transferred to the hybrid laminate in load directions with an active prevention of contact corrosion. The interface strength between thermoplastic and metal component was improved by a thermal spray coating on the aluminum sheet. Because of the high surface roughness and porosity, mechanical interlock was used to provide high interface strength without bonding agents between both components. The resulting mechanical properties of the hybrid laminates are evaluated by three point bending tests in different load directions. The effect of local fiber orientation and layer positioning on failure and deformation mechanism is additionally investigated by digital image correlation (DIC).

  16. 国外FRP预浸料发展概况%Foreign Developments of FRP Prepregs

    Institute of Scientific and Technical Information of China (English)

    叶鼎铨

    2013-01-01

    Prepregs are semi-finished fiber reinforced plastics ( FRP ) products that are pre-impregnated with resin and can be stored, ready to be used for molding composite end-products. Prepregs are divided into thermoset and thermoplastic preppregs. Due to their ease of use, consistent properties, low void content, clean molding operation and other advantages, prepregs are becoming increasingly common in the composite industry, exhibiting a very good prospect.%预浸料是用树脂预先浸渍,可以储存的纤维增强塑料( FRP)半成品,随时可以用来制造复合材料制品。预浸料有热固性和热塑性预浸料之分。因它们容易使用、性能稳定、空隙率低、模塑过程清洁等诸多优点,预浸料在复合材料工业中日趋普遍,前景甚好。

  17. sFRP2 in the aged microenvironment drives melanoma metastasis and therapy resistance

    Science.gov (United States)

    Kaur, Amanpreet; Webster, Marie R.; Marchbank, Katie; Behera, Reeti; Ndoye, Abibatou; Kugel, Curtis H.; Dang, Vanessa M.; Appleton, Jessica; O’Connell, Michael P.; Cheng, Phil; Valiga, Alexander A.; Morissette, Rachel; McDonnell, Nazli B.; Ferrucci, Luigi; Kossenkov, Andrew V.; Meeth, Katrina; Tang, Hsin-Yao; Yin, Xiangfan; Wood, William H.; Lehrmann, Elin; Becker, Kevin G.; Flaherty, Keith T.; Frederick, Dennie T.; Wargo, Jennifer A.; Cooper, Zachary A.; Tetzlaff, Michael T.; Hudgens, Courtney; Aird, Katherine M.; Zhang, Rugang; Xu, Xiaowei; Liu, Qin; Bartlett, Edmund; Karakousis, Giorgos; Eroglu, Zeynep; Lo, Roger S.; Chan, Matthew; Menzies, Alexander M.; Long, Georgina V.; Johnson, Douglas B.; Sosman, Jeffrey; Schilling, Bastian; Schadendorf, Dirk; Speicher, David W.; Bosenberg, Marcus; Ribas, Antoni; Weeraratna, Ashani T.

    2016-01-01

    Cancer is a disease of aging, and aged cancer patients have a poorer prognosis. This may be due to accumulated cellular damage, decreases in adaptive immunity, and chronic inflammation. However, the effects of the aged microenvironment on tumor progression have been largely unexplored. Since dermal fibroblasts can have profound impacts on melanoma progression1–4 we examined whether age-related changes in dermal fibroblasts could drive melanoma metastasis and response to targeted therapy. We find that aged fibroblasts secrete a Wnt antagonist, sFRP2, which activates a multi-step signaling cascade in melanoma cells that results in a decrease in β-catenin and MITF, and ultimately the loss of a key redox effector, APE1. Loss of APE1 attenuates the response of melanoma cells to ROS-induced DNA damage, rendering them more resistant to targeted therapy (vemurafenib). Age-related increases in sFRP2 also augment both angiogenesis and metastasis of melanoma cells. These data provide an integrated view of how fibroblasts in the aged microenvironment contribute to tumor progression, offering new paradigms for the design of therapy for the elderly. PMID:27042933

  18. Efficacy of Thermally Conditioned Sisal FRP Composite on the Shear Characteristics of Reinforced Concrete Beams

    Directory of Open Access Journals (Sweden)

    Tara Sen

    2013-01-01

    Full Text Available The development of commercially viable composites based on natural resources for a wide range of applications is on the rise. Efforts include new methods of production and the utilization of natural reinforcements to make biodegradable composites with lignocellulosic fibers, for various engineering applications. In this work, thermal conditioning of woven sisal fibre was carried out, followed by the development of woven sisal fibre reinforced polymer composite system, and its tensile and flexural behaviour was characterized. It was observed that thermal conditioning improved the tensile strength and the flexural strength of the woven sisal fibre composites, which were observed to bear superior values than those in the untreated ones. Then, the efficacy of woven sisal fibre reinforced polymer composite for shear strengthening of reinforced concrete beams was evaluated using two types of techniques: full and strip wrapping techniques. Detailed analysis of the load deflection behaviour and fracture study of reinforced concrete beams strengthened with woven sisal under shearing load were carried out, and it was concluded that woven sisal FRP strengthened beams, underwent very ductile nature of failure, without any delamination or debonding of sisal FRP, and also increased the shear strength and the first crack load of the reinforced concrete beams.

  19. 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.

  20. 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.

  1. 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.

  2. 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...

  3. 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...

  4. 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.

  5. 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.

  6. 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.

  7. 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

  8. 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)

  9. 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...

  10. 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.

  11. 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.

  12. 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...

  13. 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.

  14. Accelerated aging tests for evaluation of shear behavior of FRP connectors in precast sandwich insulation wall panels%预制夹芯保温墙体FRP连接件抗剪性能加速老化试验研究

    Institute of Scientific and Technical Information of China (English)

    薛伟辰; 付凯; 李向民

    2012-01-01

    为实现预制夹芯保温墙体主体结构与围护结构同寿命,有必要开展混凝土环境下预制夹芯保温墙体纤维增强塑料(FRP)连接件的力学性能(主要是层间剪切性能)的加速老化试验研究。基于ACI 440.3R-04规定的试验方法,将30根预制夹芯保温墙体FRP连接件浸入60℃的模拟混凝土溶液中进行加速老化试验,侵蚀时间分别为3.65,18,36.5,92,183d,主要分析了侵蚀时间对FRP连接件层间剪切强度的影响。研究表明,在60℃模拟混凝土溶液环境下,FRP连接件的层间剪切强度早期退化较快,侵蚀36.5d后,退化速率逐渐变缓;侵蚀36.5d和183d后,FRP连接件的层间剪切强度分别下降了17.22%和26.89%。扫描电子显微镜(SEM)的观测表明,侵蚀后FRP连接件劣化区域内的纤维与周围树脂之间出现了明显的脱粘现象,而且随着侵蚀时间的增加这种脱粘现象更加明显。%In order to make the main structure of the precast sandwich insulation wall panel to have the same life with building envelope,it is necessary to conduct the accelerated aging tests for evaluation of mechanical property(mainly its interlaminar shear strength) for FRP connectors under simulated concrete environment.According to the ACI 440.3R-04,the test consisting of 30 FRP connectors in 60℃ of simulated concrete environment for 3.65,18,36.5,92,183d was conducted to evaluate the interlaminar shear strength of FRP connectors under simulated concrete environment.The results show that,with the aging time,the interlaminar shear strength of FRP connectors decreased significantly before 36.5d.After being exposed to simulated concrete environment for 36.5,183d,interlaminar shear strength degradation of FRP connectors were 17.22%and 26.89% respectively.The micro-formation of the FRP connectors' surface was surveyed under scanning electron microscopy(SEM),and it indicates that the bonds between fiber and resin of FRP connectors in the

  15. 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.

  16. 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

  17. Experimental and Numerical Investigation of the FRP Shear Mechanism for Concrete Sandwich Panels

    DEFF Research Database (Denmark)

    Hodicky, Kamil; Sopal, G.; Rizkalla, S.

    2015-01-01

    in this paper examined the effect of various parameters believed to affect the shear flow strength for this CFRP grid/foam system. The parameters that were considered are the spacing between vertical lines of CFRP grids and the thickness of the rigid foam. Results of the experimental aspect of the research......This paper investigates the composite action of 46 segments representing precast concrete sandwich panels (PCSPs) using a fiber-reinforced polymer [FRP; specifically, a carbon fiber-reinforced polymer (CFRP)] grid/rigid foam as a shear mechanism. The experimental aspect of the research reported...... of this interface surface area. Test results also indicated that increasing the rigid foam thickness decreases the overall shear flow strength when compared with the same quantity of CFRP grid spacing. A nonlinear three-dimensional (3D) FEM analysis was performed to model the behavior of the tested segments...

  18. 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)

  19. 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.

  20. Life cycle cost analysis of new FRP based solar parabolic trough collector hot water generation system

    Institute of Scientific and Technical Information of China (English)

    A. VALAN ARASU; T. SORNAKUMAR

    2008-01-01

    Parabolic trough collectors (PTCs) are employed for a variety of applications including steam generation and hot water generation. This paper deals with the experimental results and an economic analysis of a new fibre reinforced plastic (FRP) based solar PTC with an embedded electronic controlled tracking system designed and developed for hot water generation in a restaurant in Madurai, India. The new collector performance has been tested according to ASHRAE Standard 93 (1986). The performance of a new PTC hot water generation system with a well mixed hot water storage tank is investigated by a series of extensive tests over ten months period. The average maximum storage tank water temperature observed was 74.91 ℃, when no energy is withdrawn from the tank to the load during the collection period. The total cost of the new economic FRP based solar PTC for hot water generation with an embedded electronic controlled tracking system is Rs. 25000 (US$ 573) only. In the present work, life cycle savings (LCS) method is employed for a detailed economic analysis of the PTC system. A computer program is used as a tool for the economic analysis. The present worth of life cycle solar savings is evaluated for the new solar PTC hot water generation system that replaces an existing electric water heating system in the restaurant and attains a value of Rs. 23171.66 after 15 years, which is a significant saving. The LCS method and the MATLAB computer simulation program presented in this paper can be used to estimate the LCS of other renewable energy systems.

  1. An Extensible Sensing and Control Platform for Building Energy Management

    Energy Technology Data Exchange (ETDEWEB)

    Rowe, Anthony [Carnegie Mellon Univ., Pittsburgh, PA (United States); Berges, Mario [Carnegie Mellon Univ., Pittsburgh, PA (United States); Martin, Christopher [Robert Bosch LLC, Anderson, SC (United States)

    2016-04-03

    The goal of this project is to develop Mortar.io, an open-source BAS platform designed to simplify data collection, archiving, event scheduling and coordination of cross-system interactions. Mortar.io is optimized for (1) robustness to network outages, (2) ease of installation using plug-and-play and (3) scalable support for small to large buildings and campuses.

  2. 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

  3. Shearography and pulsed stimulated infrared thermography applied to a nondestructive evaluation of FRP strengthening systems bonded on concrete structures

    OpenAIRE

    Taillade, Frédéric; Quiertant, Marc; Benzarti, Karim; Aubagnac, Christophe

    2011-01-01

    This paper presents two complementary techniques, shearography and pulsed stimulated infrared thermography, used to detect and characterize depth and width of the adhesion defects (delaminations or adhesive disbonds) of externally bonded fiber-reinforced polymers (FRP) on concrete surface structures. Shearography associated to a depressure load on the one hand, and step heating infrared thermography on the other hand are presented. In a first step, the feasibility study of the two methods is ...

  4. Binding of sFRP-3 to EGF in the extra-cellular space affects proliferation, differentiation and morphogenetic events regulated by the two molecules.

    Directory of Open Access Journals (Sweden)

    Raffaella Scardigli

    Full Text Available BACKGROUND: sFRP-3 is a soluble antagonist of Wnts, widely expressed in developing embryos. The Wnt gene family comprises cysteine-rich secreted ligands that regulate cell proliferation, differentiation, organogenesis and oncogenesis of different organisms ranging from worms to mammals. In the canonical signal transduction pathway Wnt proteins bind to the extracellular domain of Frizzled receptors and consequently recruit Dishevelled (Dsh to the cell membrane. In addition to Wnt membrane receptors belonging to the Frizzled family, several other molecules have been described which share homology in the CRD domain and lack the putative trans-membrane domain, such as sFRP molecules (soluble Frizzled Related Protein. Among them, sFRP-3 was originally isolated from bovine articular cartilage and also as a component of the Spemann organizer. sFRP-3 blocks Wnt-8 induced axis duplication in Xenopus embryos and binds to the surface of cells expressing a membrane-anchored form of Wnt-1. Injection of sFRP-3 mRNA blocks expression of XMyoD mRNA and leads to embryos with enlarged heads and shortened trunks. METHODOLOGY/PRINCIPAL FINDINGS: Here we report that sFRP-3 specifically blocks EGF-induced fibroblast proliferation and foci formation. Over-expression of sFRP-3 reverts EGF-mediated inhibition of hair follicle development in the mouse ectoderm while its ablation in Xenopus maintains EGF-mediated inhibition of ectoderm differentiation. Conversely, over-expression of EGF reverts the inhibition of somitic myogenesis and axis truncation in Xenopus and mouse embryos caused by sFRP-3. In vitro experiments demonstrated a direct binding of EGF to sFRP-3 both on heparin and on the surface of CHO cells where the molecule had been membrane anchored. CONCLUSIONS/SIGNIFICANCE: sFRP-3 and EGF reciprocally inhibit their effects on cell proliferation, differentiation and morphogenesis and indeed are expressed in contiguous domains of the embryo, suggesting that in

  5. 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

  6. Concrete Infill Monitoring in Concrete-Filled FRP Tubes Using a PZT-Based Ultrasonic Time-of-Flight Method.

    Science.gov (United States)

    Luo, Mingzhang; Li, Weijie; Hei, Chuang; Song, Gangbing

    2016-12-07

    Concrete-filled fiber-reinforced polymer tubes (CFFTs) have attracted interest for their structural applications in corrosive environments. However, a weak interfacial strength between the fiber-reinforced polymer (FRP) tube and the concrete infill may develop due to concrete shrinkage and inadequate concrete compaction during concrete casting, which will destroy the confinement effect and thereby reduce the load bearing capacity of a CFFT. In this paper, the lead zirconate titanate (PZT)-based ultrasonic time-of-flight (TOF) method was adopted to assess the concrete infill condition of CFFTs. The basic idea of this method is that the velocity of the ultrasonic wave propagation in the FRP material is about half of that in concrete material. Any voids or debonding created along the interface between the FRP tube and the concrete will delay the arrival time between the pairs of PZT transducers. A comparison of the arrival times of the PZT pairs between the intact and the defected CFFT was made to assess the severity of the voids or the debonding. The feasibility of the methodology was analyzed using a finite-difference time-domain-based numerical simulation. Experiments were setup to validate the numerical results, which showed good agreement with the numerical findings. The results showed that the ultrasonic time-of-flight method is able to detect the concrete infill condition of CFFTs.

  7. Effects of Elevated Temperatures on the Compressive Strength Capacity of Concrete Cylinders Confined with FRP Sheets: An Experimental Investigation

    Directory of Open Access Journals (Sweden)

    Sherif El-Gamal

    2015-01-01

    Full Text Available Due to their high strength, corrosion resistance, and durability, fiber reinforced polymers (FRP are very attractive for civil engineering applications. One of these applications is the strengthening of concrete columns with FRP sheets. The performance of this strengthening technique at elevated temperature is still questionable and needs more investigations. This research investigates the effects of exposure to high temperatures on the compressive strength of concrete cylinders wrapped with glass and carbon FRP sheets. Test specimens consisted of 30 unwrapped and 60 wrapped concrete cylinders. All specimens were exposed to temperatures of 100, 200, and 300°C for periods of 1, 2, and 3 hours. The compressive strengths of the unwrapped concrete cylinders were compared with their counterparts of the wrapped cylinders. For the unwrapped cylinders, test results showed that the elevated temperatures considered in this study had almost no effect on their compressive strength; however, the wrapped specimens were significantly affected, especially those wrapped with GFRP sheets. The compressive strength of the wrapped specimens decreased as the exposure period and the temperature level increased. After three hours of exposure to 300°C, a maximum compressive strength loss of about 25.3% and 37.9%, respectively, was recorded in the wrapped CFRP and GFRP specimens.

  8. Wnt, Frizzled, and sFRP gene expression patterns during gastrulation in the starfish Patiria (Asterina) pectinifera.

    Science.gov (United States)

    Kawai, Narudo; Kuraishi, Ritsu; Kaneko, Hiroyuki

    2016-05-01

    By the initial phase of gastrulation, Wnt pathway regulation mediates endomesoderm specification and establishes the animal-vegetal axis, thereby leading to proper gastrulation in starfish. To provide insight into the ancestral mechanism regulating deuterostome gastrulation, we identified the gene expression patterns of Wnt, Frizzled (Fz), and secreted frizzled-related protein (sFRP) family genes, which play a role in the initial stage of the Wnt pathway, in starfish Patiria (Asterina) pectinifera embryos using whole mount in situ hybridization. We identified ten Wnt, four Fz, and two sFRP paralogues. From the hatching blastula to the late gastrula stage, the majority of the Wnt genes and both Fz5/8 and sFRP1/5 were expressed in the posterior and anterior half of the embryo, respectively. Wnt8, Fz1, and Fz4 showed restricted expression in the lateral ectoderm. On the other hand, several genes were expressed de novo in the restricted domain of the archenteron at the late gastrula stage. These results suggest that the canonical and/or non-canonical Wnt pathway might implicate endomesoderm specification, anterior-posterior axis establishment, anterior-posterior patterning, and archenteron morphogenesis in the developmental context of starfish embryos. From comparison with the expression patterns observed in Patria miniata, we consider that the Wnt pathway is conserved among starfishes.

  9. Technique for reduction of mechanical losses in AC superconducting coils due to thermal expansion properties of various FRP bobbins

    Science.gov (United States)

    Sekine, N.; Tada, S.; Higuchi, T.; Furumura, Y.; Takao, T.; Yamanaka, A.

    2005-10-01

    We reported about reduction of mechanical losses in AC superconducting coils. The method is the use of FRP bobbins fabricated with special fibers. Since their FRPs have negative thermal expansion coefficient to the fiber direction, the FRP bobbins expand to the circumferential direction during cooling down. In case of the superconducting coils with such FRP bobbins, the winding tensions do not decrease during cooling down. Therefore, the mechanical losses are reduced by the suppression of wire's vibration. Their special FRPs are a Dyneema® fiber reinforced plastic (DFRP), a Dyneema and glass fiber reinforced plastic (DGFRP), and a Zylon® fiber reinforced plastic (ZFRP). These materials have negative thermal expansion coefficient to the fiber direction, however, the amplitudes of thermal expansion are various by the quantity or quality of the fiber. In this paper, the values of thermal expansion were actually measured, and it was discussed about the influence on the mechanical losses. At the experimental results, the mechanical loss was small, so that the thermal strain to the circumferential direction on the coil was large. Moreover, in case of the coils with sufficiently strong winding tensions at coil-operating temperature, the mechanical losses vanished.

  10. Technique for reduction of mechanical losses in AC superconducting coils due to thermal expansion properties of various FRP bobbins

    Energy Technology Data Exchange (ETDEWEB)

    Sekine, N. [Tsukamoto Laboratory, Faculty of Engineering, Yokohama National University, 79-5, Tokiwadai, Hodogaya-ku, Yokohama 240-8501 (Japan)]. E-mail: n-sekine@tsukalab.dnj.ynu.ac.jp; Tada, S. [Sophia University, 7-1, Kioicho, Chiyoda-ku, Tokyo 102-8554 (Japan); Higuchi, T. [Sophia University, 7-1, Kioicho, Chiyoda-ku, Tokyo 102-8554 (Japan); Furumura, Y. [Sophia University, 7-1, Kioicho, Chiyoda-ku, Tokyo 102-8554 (Japan); Takao, T. [Sophia University, 7-1, Kioicho, Chiyoda-ku, Tokyo 102-8554 (Japan); Yamanaka, A. [Research Center, Toyobo, Co., Ltd, 2-1-1, Katata, Otsu, Shiga 520-0292 (Japan)

    2005-10-01

    We reported about reduction of mechanical losses in AC superconducting coils. The method is the use of FRP bobbins fabricated with special fibers. Since their FRPs have negative thermal expansion coefficient to the fiber direction, the FRP bobbins expand to the circumferential direction during cooling down. In case of the superconducting coils with such FRP bobbins, the winding tensions do not decrease during cooling down. Therefore, the mechanical losses are reduced by the suppression of wire's vibration. Their special FRPs are a Dyneema[reg] fiber reinforced plastic (DFRP), a Dyneema and glass fiber reinforced plastic (DGFRP), and a Zylon[reg] fiber reinforced plastic (ZFRP). These materials have negative thermal expansion coefficient to the fiber direction, however, the amplitudes of thermal expansion are various by the quantity or quality of the fiber. In this paper, the values of thermal expansion were actually measured, and it was discussed about the influence on the mechanical losses. At the experimental results, the mechanical loss was small, so that the thermal strain to the circumferential direction on the coil was large. Moreover, in case of the coils with sufficiently strong winding tensions at coil-operating temperature, the mechanical losses vanished.

  11. Rapid Repair of Earthquake Damaged RC Interior Beam-wide Column Joints and Beam-wall Joints Using FRP Composites

    Institute of Scientific and Technical Information of China (English)

    LI Bing; LIM Chee Leong

    2009-01-01

    This paper studies the seismic performance of FRP-strengthened RC interior non-seismically detailed beam-wide columns and beam-wall joints after limited seismic damage. Four eccentric and concentric beam-wide column joints and two beam-wall joints, initially damaged in a previous study, were repaired and tested under constant axial loads (0. \\fc'Ag and 0. 35 fc'Ag ) and lateral cyclic loading. The rapid repair technique developed, aimed to restore the original strength and to provide minimum drift capacity. The repair schemes were characterized by the use of; (a) epoxy injections and polymer modified cementitious mortar to seal the cracks and replace spalled concrete; and (b) glass (GFRP) and carbon (CFRP) sheets to enhance the joint performance. The FRP sheets were effectively prevented against possible debonding through the use of fiber anchors. Comparison between responses of specimens before and after repair clearly indicated reasonable restoration in strength, drift capacity, stiffness and cumulative energy dissipation capacity. All specimens failed with delamination of FRP sheets at beam-column joint interfaces. The rapid repair technique developed in this study is recommended for mass upgrading or repair of earthquake damaged beam-column joints.

  12. Estimating Landscape Fire Particulate Matter (PM) Emissions over Southern Africa using MSG-SEVIRI Fire Radiative Power (FRP) and MODIS Aerosol Optical Thickness Observations

    Science.gov (United States)

    Mota, Bernardo; Wooster, Martin J.

    2016-04-01

    The approach to estimating landscape fire fuel consumption based on the remotely sensed fire radiative power (FRP) thermal energy release rate, as opposed to burned area, is now relatively widely used in studies of fire emissions, including operationally within the Copernicus Atmosphere Monitoring Service (CAMS). Nevertheless, there are still limitations to the approach, including uncertainties associated with using only the few daily overpasses typically provided by polar orbiting satellite systems, the conversion between FRP and smoke emissions, and the increased likelihood that the more frequent data from geostationary systems fails to detect the (probably highly numerous) smaller (i.e. low FRP) component of a regions fire regime. In this study, we address these limitations to directly estimate fire emissions of Particular Matter (PM; or smoke aerosols) by presenting an approach combining the "bottom-up" FRP observations available every 15 minutes across Africa from the Meteosat Spinning Enhanced Visible and Infrared Imager (SEVIRI) Fire Radiative Product (FRP) processed at the EUMETSAT LSA SAF, and the "top-down" aerosol optical thickness (AOT) measures of the fire plumes themselves as measured by the Moderate-resolution Imaging Spectro-radiometer (MODIS) sensors aboard the Terra (MOD04_L2) and Aqua (MYD04_L2) satellites. We determine PM emission coefficients that relate directly to FRP measures by combining these two datasets, and the use of the almost continuous geostationary FRP observations allows us to do this without recourse to (uncertain) data on wind speed at the (unknown) height of the matching plume. We also develop compensation factors to address the detection limitations of small/low intensity (low FRP) fires, and remove the need to estimate fuel consumption by going directly from FRP to PM emissions. We derive the smoke PM emissions coefficients per land cover class by comparing the total fire radiative energy (FRE) released from individual fires

  13. Mode-I fracture and durability of FRP-concrete bonded interfaces

    Directory of Open Access Journals (Sweden)

    Qiao Pizhong

    2008-12-01

    Full Text Available In this study, a work-of-fracture method using a three-point bend beam (3PBB specimen, which is commonly used to determine the fracture energy of concrete, was adapted to evaluate the mode-I fracture and durability of fiber-reinforced polymer (FRP composite-concrete bonded interfaces. Interface fracture properties were evaluated with established data reduction procedures. The proposed test method is primarily for use in evaluating the effects of freeze-thaw (F-T and wet-dry (W-D cycles that are the accelerated aging protocols on the mode-I fracture of carbon FRP-concrete bonded interfaces. The results of the mode-I fracture tests of F-T and W-D cycle-conditioned specimens show that both the critical load and fracture energy decrease as the number of cycles increases, and their degradation pattern has a nearly linear relationship with the number of cycles. However, compared with the effect of the F-T cycles, the critical load and fracture energy degrade at a slower rate with W-D cycles, which suggests that F-T cyclic conditioning causes more deterioration of carbon fiber-reinforced polymer (CFRP-concrete bonded interface. After 50 and 100 conditioning cycles, scaling of concrete was observed in all the specimens subjected to F-T cycles, but not in those subjected to W-D cycles. The examination of interface fracture surfaces along the bonded interfaces with varying numbers of F-T and W-D conditioning cycles shows that (1 cohesive failure of CFRP composites is not observed in all fractured surfaces; (2 for the control specimens that have not been exposed to any conditioning cycles, the majority of interface failure is a result of cohesive fracture of concrete (peeling of concrete from the concrete substrate, which means that the cracks mostly propagate within the concrete; and (3 as the number of F-T or W-D conditioning cycles increases, adhesive failure along the interface begins to emerge and gradually increases. It is thus concluded that the

  14. Mode-Ⅰ fracture and durability of FRP-concrete bonded interfaces

    Institute of Scientific and Technical Information of China (English)

    Qiao Pizhong; Xu Yingwu

    2008-01-01

    In this study, a work-of-fracture method using a three-point bend beam (3PBB) specimen, which is commonly used to determine the fracture energy of concrete, was adapted to evaluate the mode-Ⅰ fracture and durability of fiber-reinforced polymer (FRP) composite-concrete bonded interfaces. Interface fracture properties were evaluated with established data reduction procedures. The proposed test method is primarily for use in evaluating the effects of freeze-thaw (F-T) and wet-dry (W-D) cycles that are the accelerated aging protocols on the mode-Ⅰ fracture of carbon FRP-concrete bonded interfaces. The results of the mode-Ⅰ fracture tests of F-T and W-D cycle-conditioned specimens show that both the critical load and fracture energy decrease as the number of cycles increases, and their degradation pattern has a nearly linear relationship with the number of cycles. However, compared with the effect of the F-T cycles, the critical load and fracture energy degrade at a slower rate with W-D cycles, which suggests that F-T cyclic conditioning causes more deterioration of carbon fiber-reinforced polymer (CFRP)-concrete bonded interface. After 50 and 100 conditioning cycles, scaling of concrete was observed in all the specimens subjected to F-T cycles, but not in those subjected to W-D cycles. The examination of interface fracture surfaces along the bonded interfaces with varying numbers of F-T and W-D conditioning cycles shows that (1) cohesive failure of CFRP composites is not observed in all fractured surfaces; (2) for the control specimens that have not been exposed to any conditioning cycles, the majority of interface failure is a result of cohesive fracture of concrete (peeling of concrete from the concrete substrate), which means that the cracks mostly propagate within the concrete; and (3) as the number of F-T or W-D conditioning cycles increases, adhesive failure along the interface begins to emerge and gradually increases. It is thus concluded that the fracture

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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)

  20. 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.

  1. 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...

  2. 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...

  3. 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).

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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%.

  9. 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.

  10. 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.

  11. 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.

  12. 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)

  13. 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 ...

  14. 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

  15. 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...

  16. 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)

  17. 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.

  18. 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.

  19. 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.

  20. 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...

  1. 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...

  2. 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.

  3. 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.

  4. 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.

  5. The Influence of Fiber Type and Conformation on the Damping Property of FRP Composite

    Institute of Scientific and Technical Information of China (English)

    WANG Xiang; CHEN Wei; WANG Jun; LIU Hanxing

    2012-01-01

    In order to get a fiber reinforced plastic(FRP) composite with good damping property as well as good mechanical properties,different types of reinforcing materials were used to reinforcing a damping resin.The influence of fiber types and conformation on the damping property of the composite are tested.Compared to the glass fiber(GF),carbon fiber(CF) can improve the damping factor of the composites; the highest tanδ value is 0.827 while the Tg is 22.5 ℃.The style of the fibers also influences the damping factors of the composite.The composite reinforced with mat has higher loss factors than that composite reinforced with clothe for the reason that the former has the ability to deform and the composite has higher resin content.The loss factor of GF mat reinforced composite is 0.704 while the T is 27 ℃.Both composite has good damping properties and can be used as the damping layer of the structural damping composite.

  6. Research and Development on Control System of Novel Winding Machine for High-pressure FRP Pipeline

    Institute of Scientific and Technical Information of China (English)

    YOU Bo; XU Jiazhong; HU Haiyan; CHENG Ningbo; ZHANG Qingli

    2006-01-01

    The novel winding machine adopted steam inside solidification technics, can wind, solidify and extract high-pressure fiber reinforced plastic (FRP) pipelines in one single machine. Its control system consisted of the winding and extraction subsystem and the steam inside solidification subsystem. In order to improve the control precision and stability, a real-time control method was adopted in the winding and extraction subsystem. In this method, high-precision TRIO motion controller combined with industrial personal computer (IPC) forms an open-type CNC system which supports multitask. The Modbus protocol was adopted for the communication between the IPC and TRIO motion controller. The human-machine interface (HMI) was developed with VC++ 6.0 and the control software of the motion controller was developed with TRIO BASIC language. In the steam inside solidification subsystem, embedded IPC and PLC were used to realize the closed-loop control of the steam temperature and the HMI was developed with MCGS 5.1 under WinCE. Practices show that this system has the good performances of high precision, good stability and high efficiency.

  7. Mechanical Properties of Steel-FRP Composite Bars under Tensile and Compressive Loading

    Directory of Open Access Journals (Sweden)

    Zeyang Sun

    2017-01-01

    Full Text Available The factory-produced steel-fiber reinforced polymer composite bar (SFCB is a new kind of reinforcement for concrete structures. The manufacturing technology of SFCB is presented based on a large number of handmade specimens. The calculated stress-strain curves of ordinary steel bar and SFCB under repeated tensile loading agree well with the corresponding experimental results. The energy-dissipation capacity and residual strain of both steel bar and SFCB were analyzed. Based on the good simulation results of ordinary steel bar and FRP bar under compressive loading, the compressive behavior of SFCB under monotonic loading was studied using the principle of equivalent flexural rigidity. There are three failure modes of SFCB under compressive loading: elastic buckling, postyield buckling, and no buckling (ultimate compressive strength is reached. The increase in the postyield stiffness of SFCB rsf can delay the postyield buckling of SFCB with a large length-to-diameter ratio, and an empirical equation for the relationship between the postbuckling stress and rsf is suggested, which can be used for the design of concrete structures reinforced by SFCB to consider the effect of reinforcement buckling.

  8. Microtomographic Analysis of Impact Damage in FRP Composite Laminates: A Comparative Study

    Directory of Open Access Journals (Sweden)

    M. Alemi-Ardakani

    2013-01-01

    Full Text Available With the advancement of testing tools, the ability to characterize mechanical properties of fiber reinforced polymer (FRP composites under extreme loading scenarios has allowed designers to use these materials in high-level applications more confidently. Conventionally, impact characterization of composite materials is studied via nondestructive techniques such as ultrasonic C-scanning, infrared thermography, X-ray, and acoustography. None of these techniques, however, enable 3D microscale visualization of the damage at different layers of composite laminates. In this paper, a 3D microtomographic technique has been employed to visualize and compare impact damage modes in a set of thermoplastic laminates. The test samples were made of commingled polypropylene (PP and glass fibers with two different architectures, including the plain woven and unidirectional. Impact testing using a drop-weight tower, followed by postimpact four-point flexural testing and nondestructive tomographic analysis demonstrated a close relationship between the type of fibre architecture and the induced impact damage mechanisms and their extensions.

  9. 燃煤电厂玻璃钢烟道设计与研究%Design Research of FRP Flue for Coal-ifred Power Plant

    Institute of Scientific and Technical Information of China (English)

    罗树青; 董胜宪; 丁安心; 王继辉

    2015-01-01

    The temperature of flue gas disposed by wet flue gas desulfurization is lower without gas heater (GGH) and large number of condensate which have strong corrosion toward the FRP flue, are produced by reason of condensation of the flue gas in the inner wall, FRP flue has the dual nature of both structural and functional materials and can meet the requirements of power plants. Firstly, this paper mainly introduced the application situation of FRP flue at home and abroad. The quantities of FRP flue installed are increasing abroad and FRP flue became one of important corrosion resistance materials in the developed country like American and Europe. The application of FRP flue start in recent years and a few of FRP flue was in the service, but the development of FRP flue is quick and the design standard and product standard of FRP flue have been published at home. In generally, the understanding in the design and construction is still lacking. Finally, the author discuss and research the resin material selection and joint design of FRP flue according to the FRP liner and FRP flue engineering which the author participate and design experience of FRP product.%经过湿法脱硫且不加装烟气加热装置的烟气的温度比较低,烟气在烟道内壁冷凝产生大量的冷凝液,对烟道的腐蚀很大,玻璃钢烟道集功能性和结构一体,能满足电厂的运行要求。本文首先阐述了玻璃钢烟道在国内外的应用研究现状,在国外玻璃钢烟道的安装数量不断增加,已经成为主要烟道防腐材料之一;国内玻璃钢烟道应用已有几年时间,发展较快,已经出版了相应的设计标准或产品标准。但总的来说,国内对玻璃钢烟道设计及施工认识还不够。最后作者利用自己参与的玻璃钢烟道、烟道工程及相关的玻璃钢制品的设计经验,对玻璃钢烟道树脂原材料的选材、玻璃钢烟道接口设计进行了简单的探讨和研究。

  10. Meteosat SEVIRI Fire Radiative Power (FRP products from the Land Surface Analysis Satellite Applications Facility (LSA SAF – Part 1: Algorithms, product contents and analysis

    Directory of Open Access Journals (Sweden)

    M. J. Wooster

    2015-06-01

    Full Text Available Characterising changes in landscape scale fire activity at very high temporal resolution is best achieved using thermal observations of actively burning fires made from geostationary Earth observation (EO satellites. Over the last decade or more, a series of research and/or operational "active fire" products have been developed from these types of geostationary observations, often with the aim of supporting the generation of data related to biomass burning fuel consumption and trace gas and aerosol emission fields. The Fire Radiative Power (FRP products generated by the Land Surface Analysis Satellite Applications Facility (LSA SAF from data collected by the Meteosat Second Generation (MSG Spinning Enhanced Visible and Infrared Imager (SEVIRI are one such set of products, and are freely available in both near real-time and archived form. Every 15 min, the algorithms used to generate these products identify and map the location of new SEVIRI observations containing actively burning fires, and characterise their individual rates of radiative energy release (fire radiative power; FRP that is believed proportional to rates of biomass consumption and smoke emission. The FRP-PIXEL product contains the highest spatial resolution FRP dataset, delivered for all of Europe, northern and southern Africa, and part of South America at a spatial resolution of 3 km (decreasing away from the west African sub-satellite point at the full 15 min temporal resolution. The FRP-GRID product is an hourly summary of the FRP-PIXEL data, produced at a 5° grid cell size and including simple bias adjustments for meteorological cloud cover and for the regional underestimation of FRP caused, primarily, by the non-detection of low FRP fire pixels at SEVIRI's relatively coarse pixel size. Here we describe the enhanced geostationary Fire Thermal Anomaly (FTA algorithm used to detect the SEVIRI active fire pixels, and detail methods used to deliver atmospherically corrected FRP

  11. Antagonizing canonical Wnt signaling pathway by recombinant human sFRP4 purified from E. coli and its implications in cancer therapy.

    Science.gov (United States)

    Ghoshal, Archita; Ghosh, Siddhartha Sankar

    2016-07-01

    The Wnt signaling pathway plays a predominant role in aberrant proliferation in myriad of cancers. In non-cancerous cells, Wnts are blocked by the secreted frizzled-related proteins (sFRPs) that are generally downregulated in cancer cells. We have purified and characterized bacterially expressed glutathione S-transferase-tagged SFRP4 from a novel clone generated from human cell origin. Cervical cancer (HeLa) and lung cancer (A549) cells, in which Wnt and associated genes were found to be expressed, were treated with the purified recombinant sFRP4, which revealed a significant dose-dependent cell growth inhibition up to 40 %. The current investigation on functionality of this bacterially produced recombinant sFRP4 in arresting cancer cell proliferation is the first of its kind, where G2/M phase arrest and early apoptosis were evident. Increase in phosphorylated β-catenin in sFRP4 treatment indicated inhibition of Wnt pathway, which was further confirmed by downregulation of pro-proliferative genes, namely cyclin D1, c-myc, and survivin. Functional activity of recombinant sFRP4 was further exploited in co-therapy module with chemotherapeutic drugs to decipher molecular events. Collectively, our study on purified recombinant sFRP4 from bacterial host holds great promise in targeting Wnt signaling for exploring new strategies to combat cancer.

  12. FRP 加固 RC 连续梁桥抗震性能试验研究%Tests for aseismic performances of a RC continuous girder bridge retrofitted by FRP jacket

    Institute of Scientific and Technical Information of China (English)

    林元铮; 田石柱

    2016-01-01

    Taking a reinforced concrete continuous girder bridge as the study object,retrofitting the plastic region of piers with FRP jacket,the aseismic performances of the bridge structure were studied with hybrid tests.The fixed pier bearing most seismic action was taken as a test element and physically tested in a lab while the other parts of the bridge structure were taken as calculation elements and simulated numerically with OpenSees.After integrating and combining different parts with the hybrid test platform--OpenFresco,the dynamic responses of the overall bridge structure under seismic action were obtained.At last,the test results and Open Sees finite element analysis ones were compared.The results showed that the aseismic performances of the RC continuous girder bridge can be improved effectively after retrofitted with FRP jacket,and the test results agree well with those of finite element analysis.%以某钢筋混凝土连续梁桥作为研究对象,对其桥墩进行了塑性铰区的 FRP 抗震加固,采用混合试验技术研究了该桥梁结构的抗震性能。将连续梁桥结构承担主要地震作用的固定墩作为试验单元,进行真实的物理试验;将桥梁结构其余部分作为计算单元通过有限元软件 OpenSees 进行模拟,通过 OpenFresco 混合试验平台集成协调,完成了该连续梁桥的抗震混合试验。最后将试验结果与 OpenSees 有限元分析结果进行了对比。研究结果表明,FRP 抗震加固能够有效改善桥梁的抗震性能;试验结果与有限元分析结果吻合较好。

  13. 玻璃钢活节式灯桩的设计计算%DESIGN CALCULATION OF FRP LIGHTSTAKE WITH FLEXIBLE JOINTS

    Institute of Scientific and Technical Information of China (English)

    赵会娟; 林维学; 付秀君; 王喜斌

    2001-01-01

    本文探讨了玻璃钢活节灯桩的设计计算思想,给出了玻璃钢活节式灯桩静水力性能、环境荷载、水动力性能和灯桩沉块的计算方法。%The article explores the idea in designing and res earching FRP lightstake with flexible joints. It provides the calculating methods of performance of FRP lightstake in static water force, environmental lo ad the motive power of water as well as sinking block .

  14. 浅谈手糊产品用玻璃钢模具的制作%DlSCUSSION ON PRODUCTION OF FRP-MOULD FOR CONTACT LAMINATING PRODUCTS

    Institute of Scientific and Technical Information of China (English)

    陈德华

    2001-01-01

    本文阐述了从母模设计到玻璃钢模具翻制的全过程后,又对玻璃钢模具的保养、维护作了简要分析;对提高玻璃钢模具制作水平、延长模具使用寿命具有指导意义。%The whole course from design of master mould to production of FRPmou1d is discussed in this paper and describes how to maintain FRP mould. It has guiding significance to improve FRP mould and to extend its service life.

  15. 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)

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  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. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. Study on behavior of car and driver in the very small commuter car made of FRP during collision using scale model. Under the consideration of thorax deformation of driver using airbag; FRP sei mokei ni yoru FRP sei chokeiryo jissha shototsuji no kuruma to join no anzensei ni kansuru kenkyu. Kyobu henkei tokusei wo yusuru join ni taisuru air gab no koka

    Energy Technology Data Exchange (ETDEWEB)

    Sakai, H.; Morisawa, M.; Yoshino, T. [Musashi Institute of Technology, Tokyo (Japan); Sato, T. [Keio University, Tokyo (Japan); Ishizuki, H. [Satake Co., Tokyo (Japan)

    1997-10-01

    In this study, after having performed simulation which took up scale models substituting for full scale model of commuter car made of FRP, we carried out collision tests to barrier. Here, we made enquiries about the occupant safety by changing the collision speed and the deformation characteristics of the seat belt, during head-on barrier collision using one-fifth scale models. We sought for the occupant`s safe combinations among the deformation characteristics of airbag and the thorax deformation. In this case, the degree of the occupants injury were estimated using HIC values, 3msecG and maximum deformation of the thorax. 7 refs., 5 figs.

  10. 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.

  11. 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.

  12. 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.

  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. Structural Performance of a Hybrid FRP-Aluminum Modular Triangular Truss System Subjected to Various Loading Conditions

    Directory of Open Access Journals (Sweden)

    Dongdong Zhang

    2014-01-01

    Full Text Available A novel hybrid FRP-aluminum truss system has been employed in a two-rut modular bridge superstructure composed of twin inverted triangular trusses. The actual flexural behavior of a one-rut truss has been previously investigated under the on-axis loading test; however, the structural performance of the one-rut truss subjected to an off-axis load is still not fully understood. In this paper, a geometrical linear finite element model is introduced and validated by the on-axis loading test; the structural performance of the one-rut truss subjected to off-axis load was numerically obtained; the dissimilarities of the structural performance between the two different loading cases are investigated in detail. The results indicated that (1 the structural behavior of the off-axis load differs from that of the on-axis load, and the off-axis load is the critical loading condition controlling the structural performance of the triangular truss; (2 under the off-axis load, the FRP trussed members and connectors bear certain out-of-plane bending moments and are subjected to a complicated stress state; and (3 the stress state of these members does not match that of the initial design, and optimization for the redesign of these members is needed, especially for the pretightened teeth connectors.

  15. Comparison of lock-in and pulse-phase thermography for defect characterization in FRP composites applied to concrete

    Science.gov (United States)

    Brown, Jeff; Chittineni, Sai Harsha

    2015-05-01

    Thermal imaging is a well-established technique for the non-destructive evaluation of FRP composites applied to reinforced concrete. Defect characterization using IR thermography, however, remains a topic of on-going research, and there are currently no universally accepted standards for data collection or interpretation. This research involved large scale thermography inspection of two FRP strengthened bridge girders that were removed from service after approximately 10 years of service in a potentially corrosive marine environment. Trial inspections were performed on test areas where defects could be identified using sounding methods. Two procedures showed the most promise for identifying and characterizing defects: sinusoidal (lock-in style) heating with periods ranging from 5 s to 40 s and constant step heating for 30 s followed by 60 s of cooling. Both methods resulted in a series of phase images that provided insight into the depth and general nature of detected defects. This paper presents the findings of a comparison study between these two thermal imaging techniques.

  16. 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 ...

  17. 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)

  18. 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.

  19. 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...

  20. 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.

  1. 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)

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. Fire Radiative Power (FRP)-based Emission Factors of PM2.5, CO and NOX for Remote Sensing of Biomass Burning Emissions

    Science.gov (United States)

    Karandana Gamalathge, T. D.; Chen, L. W. A.

    2015-12-01

    Large-scale biomass burning such as forest fires represents an important and yet uncertain source of air pollutants and greenhouse gases on a global scale. Due to the highly accidental nature of forest fires, satellite remote sensing could be a promising method to develop regional and global fire emission inventories on a real-time basis. Reliable fire radiative power (FRP)-based fuel consumption and emission factors are critical in this approach. In an attempt to obtain the information, laboratory combustion experiments were conducted to simultaneously monitor FRP, fuel consumption, and emissions of fine particulate matter (PM2.5), carbon monoxide (CO), and reactive nitrogen oxides (NO and NO2). FRP were quantified using temperature-resolved values from a thermal imager instead of conventionally used average temperature, as the former provides more realistic estimates. For dry Ponderosa pine branches, a common fuel in the Sierra Nevada, a strong correlation (r2 ~ 0.8) between FRP and the mass reduction rate (MRR) was found. This led to a radiative energy yield (REY) of 8.5 ± 1.2 MJ/kg, assuming blackbody radiation and a flame emissivity of 0.5. Mass-based emission factors were determined with the carbon balance approach. Considering the ratio of mass-based emission factors and the REY, FRP-based emission factors: PM2.5: 11 g/MJ, CO: 8.0 g/MJ, NO: 0.33 g/MJ, and NO2: 0.07 g/MJ were quantified. The application of this approach to other fuel types and uncertainties in the measurements will be discussed.

  8. New materials Mr. Constructor - A comparison of: Glass,FRP and Mycelium with concrete

    NARCIS (Netherlands)

    Debets, N.; Gkioka, M.; Postel, M.

    2016-01-01

    This "designers' manual" is made during the TIDO-course AR0531 Innovation and Sustainability This manual aims to inform about common and new materials, used for structural purposes. Th ree building materials are discussed. Th rough a comparison with the popular building material, concrete, their pr

  9. 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.

  10. 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…

  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. 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 ...

  13. 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.

  14. 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...

  15. 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...

  16. 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.

  17. 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)

  18. 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.

  19. 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 ...

  20. 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)

  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. 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.

  3. 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.

  4. 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.

  5. 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)

  6. 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.

  7. Research of Effective Width of FRP U-shaped Hoop Reinforcement Properties of Concrete Beams by Shear

    Directory of Open Access Journals (Sweden)

    Li Baokun

    2015-01-01

    Full Text Available The paste fiber reinforced composite material (hereinafter referred to as FRP U-shaped hoop of reinforced concrete beams interfacial debonding is an important reinforcement technology research. For the effective width of the CFRP U-shaped hoop reinforcement, it is still a lack of in-depth research, only relying on the test research huge workload, this article (ANSYS and the numerical simulation in the whole process of the shear load release properties of finite element calculation software. According to the results of finite element analysis, the author studied the CFRP U-shaped hoop to increase the width of the shear capacity of reinforced concrete beams by the impact.

  8. Pro-inflammatory wnt5a and anti-inflammatory sFRP5 are differentially regulated by nutritional factors in obese human subjects.

    Directory of Open Access Journals (Sweden)

    Dominik M Schulte

    Full Text Available BACKGROUND: Obesity is associated with macrophage infiltration of adipose tissue. These inflammatory cells affect adipocytes not only by classical cytokines but also by the secreted glycopeptide wnt5a. Healthy adipocytes are able to release the wnt5a inhibitor sFRP5. This protective effect, however, was found to be diminished in obesity. The aim of the present study was to examine (1 whether obese human subjects exhibit increased serum concentrations of wnt5a and (2 whether wnt5a and/or sFRP5 serum concentrations in obese subjects can be influenced by caloric restriction. METHODOLOGY: 23 obese human subjects (BMI 44.1 ± 1.1 kg/m(2 and 12 age- and sex-matched lean controls (BMI 22.3 ± 0.4 kg/m(2 were included in the study. Obese subjects were treated with a very low-calorie diet (approximately 800 kcal/d for 12 weeks. Body composition was assessed by impedance analysis, insulin sensitivity was estimated by HOMA-IR and the leptin-to-adiponectin ratio and wnt5a and sFRP5 serum concentrations were measured by ELISA. sFRP5 expression in human adipose tissue biopsies was further determined on protein level by immunohistology. PRINCIPAL FINDINGS: Pro-inflammatory wnt5a was not measurable in any serum sample of lean control subjects. In patients with obesity, however, wnt5a became significantly detectable consistent with low grade inflammation in such subjects. Caloric restriction resulted in a weight loss from 131.9 ± 4.0 to 112.3 ± 3.2 kg in the obese patients group. This was accompanied by a significant decrease of HOMA-IR and leptin-to-adiponectin ratio, indicating improved insulin sensitivity. Interestingly, these metabolic improvements were associated with a significant increase in serum concentrations of the anti-inflammatory factor and wnt5a-inhibitor sFRP5. CONCLUSIONS/SIGNIFICANCE: Obesity is associated with elevated serum levels of pro-inflammatory wnt5a in humans. Furthermore, caloric restriction beneficially affects serum concentrations

  9. FRP人行天桥的结构性能与设计指标研究%Research on Structural Performance and Design Indices of FRP Footbridges

    Institute of Scientific and Technical Information of China (English)

    冯鹏; 金飞飞; 叶列平

    2011-01-01

    A tentative FRP cable-stayed footbridge was investigated, in which the design method and design indices of FRP footbridges were studied. Firstly, the analysis of mechanical properties of the FRP footbridge made of large section industrialization pultruded profiles was carried out. It was found that FRP footbridge had the high loading capacity, while the deformation and the vibration comfort were the main controlling parameters for structural design. Furthermore, based on summarizing the deformation limits of the footbridge in domestic and international codes and considering the finite element analysis and the field measurement results, the deflection limit of 1/500 span length for FRP footbridge was proposed. The indices for the pedestrian vibration comfort requirements were also summarized, and the frequency limit, acceleration limit and excitation load were analyzed. Considering the finite element analysis and the field measurement results, it was concluded that the acceleration should be the controlling indicator, and simplifiedexcitation load model and calculation method for acceleration were proposed. After reviewing the variety of damping ratio of real bridge in literature, the damping ratio of FRP footbridge was suggested to take as 0. 008 for single component and 0. 02 for multi-component structures. Based on the proposed design indices above, the limit span of continuous beam FRP footbridge and cable-stayed FRP footbridge were analyzed. For the cable-stayed FRP footbridge, the results of finite element analysis and field measurement showed that it could not meet the designing requirements. Hence, the improvement of overlaying a concrete layer was proposed. After it, the behaviors of the FRP footbridge met the requirements. All these works made out the design approach and the design indices for FRP footbridges, which were proved to be practical and reasonable through the actual FRP footbridge. Results show that overlaying a concrete layer is an effective

  10. 玻璃钢蜂窝夹层结构支撑点的设计%DESIGN OF SUPPORTING SPOT INSIDE FRP HONEYCOMB SADWICH PANELS

    Institute of Scientific and Technical Information of China (English)

    何玉梅; 林有才; 等

    2001-01-01

    In this paper, strength of supporting spot inside FRP honeycomb sandwich panels are stuided on the basis of comparision of thr ee kind supporting spot models,and effect of model of supporting spot on strengt h of radome made of FRP honeycomb sandwich panels are discussed.%本文研究了某地面雷达天线罩采用的含有预埋件的玻璃钢蜂窝夹层结构支撑点的强度,把含有三种不同形式支撑点的蜂窝夹层结构试件的强度进行了对比,讨论了支撑点的形式对结构强度的影响。

  11. Application Analysis on FRP Composite Material Cable Bracket%玻璃钢复合材料电缆支架的应用分析

    Institute of Scientific and Technical Information of China (English)

    马昀涛; 李凌睿; 朱萍

    2013-01-01

    针对金属电缆支架易锈蚀等问题,介绍一种新型玻璃钢复合材料电缆支架,分析其存在优势和应用情况,认为玻璃钢复合材料电缆支架替代金属电缆支架切实可行。%Because metal cable support is easy to rust,propo-ses a new composite cable support,analyzes the advantages of FRP composite material cable support and application, considers that it is feasible to replace metal cable support with FRP composite material cable support.

  12. 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.

  13. Numerical Analysis of Interface Bonding between Fiber Reinforced Polymer and Clay Brick%FRP 与砖界面粘结性能的数值分析

    Institute of Scientific and Technical Information of China (English)

    黄奕辉; 罗才松; 黄田良

    2015-01-01

    A numerical model is proposed to this paper to simulate the bonding stress distribution on the interface be-tween fiber reinforced polymer (FRP)and brick based on finite element software ABAQUS.Using the numerical model, the load-displacement curve and the bonding stress distributions of FRP-brick interface are obtained,which shows the model is feasible.Bond bearing capacity increases with the increase of FRP′s bond length.When the bond length reaches a certain value,bond bearing capacity does not increased,but it can improve the ductility of the specimens,and raise the limit displacement.%利用有限元软件 ABAQUS 建立纤维复合材料(FRP)-砖界面分析模型,模拟其粘结应力分布,加载端荷载-位移曲线及界面应力的传递过程,并与试验结果进行对比分析。结果表明:数值模拟结果与试验结果吻合较好,采用的 FRP-砖界面计算模型具有可行性;粘结承载力随着 FRP 与砖粘结长度的增加而增加,当粘结长度达到某一定值后,粘结承载力基本不增长,此时增加粘结长度可改善试件的延性,增加试件的极限位移。

  14. 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.

  15. 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.

  16. 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'...

  17. 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.

  18. 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.

  19. 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)

  20. 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.)

  1. 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.

  2. 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.

  3. 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.

  4. 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).

  5. 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 ...

  6. 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.

  7. 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...

  8. 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.

  9. 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.

  10. 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.

  11. sFRP5抑制Wnt3a对黑素细胞黑素形成作用的初步研究%SFRP5 suppresses melanin formation of melanocytes through Wnt3a inhibition

    Institute of Scientific and Technical Information of China (English)

    汤寅虹; 杨珂; 杨恬; 叶吉星; 刘鹏; 连小华; 郭海英; 彭惠民

    2014-01-01

    目的 研究sFRP5抑制Wnt3a对黑素细胞黑素形成的作用.方法 以永生化的黑素细胞为模型,利用腺病毒表达载体,设置Control组、Wnt3a处理组、Wnt3a+ sFRP5处理组进行以下实验:L-DOPA测定酪氨酸酶(tyrosinase,TYR)活性;Masson-Fontanas银染色法观察黑素形成情况;RT-PCR检测酪氨酸酶相关蛋白1(tyrosinase-related protein 1, TRP-1)、TYR基因的表达;Western blot检测TRP-1、TYR蛋白的表达水平.结果 L-DOPA测定酪氨酸酶活性结果显示Wnt3a+ sFRP5处理组TYR活性低于Wnt3a处理组,差异有统计学意义(P<0.05);Masson-Fontanas银染色法显示Wnt3a+sFRP5处理组形成的黑素明显低于Wnt3a处理组;RT-PCR检测结果显示Wnt3a+ sFRP5处理组能下调TRP-1、TYR基因的表达(P< 0.05);Western blot检测结果显示Wnt3a+ sFRP5处理组能下调TRP-1、TYR蛋白的表达水平(P<0.05).结论 sFRP5能抑制Wnt3a对黑素细胞黑素生成的作用.

  12. 预应力纤维布混合锚固分析与试验研究%Analysis and Testing Study of Hybrid Anchorage of Prestressed FRP

    Institute of Scientific and Technical Information of China (English)

    李青松; 孟少平; 单岗; 王侠伟

    2011-01-01

    In order to improve the deficiency in the technology of embedded prestressed FRP reinforcement, with the principle of anchoring bond and additional mechanical anchoring working together, the tensioning end of prestressed FRP is anchored twice after the tension and bonding of the FRP, then removing the existing fixture and anchor. To ensure the reliability of anchoring, the paper makes a theoretical analysis of the performance of the bonding layer in the anchoring end and an experimental research on hybrid anchoring end. The research results show that the change of the performance in the bonding layer improves its anchoring ability significantly, and the steel plate can be squeezed to provide pressure to improve and enhance the performance of the bonding layer,which guarantee the quality of anchoring end. The method of combining bonding layer with hybrid anchorage of the steel plate can provide the adequate anchoring capacity, improve the construction techniques, lessen the cost and the boost the application of prestress FRP reinforcement in the practical constructions.%为了改善嵌人式预应力纤维布(FRP)加固技术的不足之处,利用粘结与机械锚固共同工作的原理,在预应力FRP张拉粘贴完毕后,对张拉端进行二次锚固,粘结层硬化后拆除原有锚夹具.为保证锚固端的可靠性,本文对锚固端粘结层的性能进行了理论分析,并对混合锚固端进行了试验研究.研究结果表明:通过改变粘结层的性能,可大幅度提高粘结层的锚固能力;钢板压条可提供挤压力,改善和提高了粘结层的受力性能,便于保证锚同端施工质量,可靠性好.采用粘结层与钢板压条混合锚固的方式可为预应力FRP提供足够的锚固力,改善了施工工艺,明显降低加固成本,促进了预应力FRP加固技术在实际工程中的应用.

  13. Development of FRP composite structural biomaterials: fatigue strength of the fiber/matrix interfacial bond in simulated in vivo environments.

    Science.gov (United States)

    Latour, R A; Black, J

    1993-10-01

    Fiber/matrix interfacial bonding in fiber reinforced polymer (FRP) composite materials is potentially sensitive to degradation in aqueous environments. Ultimate bond strength (UBS) in carbon fiber/polysulfone (CF/PSF) and polyaramid/polysulfone (K49/PSF) was previously reported to be significantly decreased in two simulated in vivo environments. While UBS is a useful parameter, for orthopedic implant applications the fatigue behavior of the interface is probably a more relevant indicator of long-term composite material performance. In this article, the effects of simulated in vivo environments (saline, exudate) upon the fatigue behavior of the interface of CF/PSF and K49/PSF are reported. The fatigue behavior of both material combinations was linearly dependent on the logarithm of fatigue life in the dry (control), saline, and exudate environments. Testing either material in saline and exudate resulted in significantly lower fatigue strength than in the dry environment; however, results in the two wet environments were indistinguishable. The CF/PSF interface experienced fatigue failure at approximately 10(5) load cycles at a maximum applied load level of only 15% of its ultimate dry bond strength without indication of an endurance limit being reached. These results raise some important questions regarding the durability of CF/PSF composite in load bearing orthopedic applications.

  14. Standard practice for determining damage-Based design Stress for fiberglass reinforced plastic (FRP) materials using acoustic emission

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2006-01-01

    1.1 This practice details procedures for establishing the direct stress and shear stress damage-based design values for use in the damage-based design criterion for materials to be used in FRP vessels and other composite structures. The practice uses data derived from acoustic emission examination of four-point beam bending tests and in-plane shear tests (see ASME Section X, Article RT-8). 1.2 The onset of lamina damage is indicated by the presence of significant acoustic emission during the reload portion of load/reload cycles. "Significant emission" is defined with historic index. 1.3 Units - The values stated in inch-pound units are to be regarded as standard. The values given in brackets are mathematical conversions to SI units which are provided for information only and are not considered standard. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health pr...

  15. A simple analytical solution for predicting deflection of a hybrid FRP-aluminum modular space truss bridge

    Institute of Scientific and Technical Information of China (English)

    李飞; 张冬冬; 赵启林; 邓安仲

    2015-01-01

    A novel hybrid FRP-aluminum space truss was employed in a two-rut modular bridge superstructure, which is composed of standard structural units. The main objective of this work was to obtain a simple analytical solution that can conveniently predict the deflection of the proposed hybrid space truss bridge. The analytical formulae are expected to possess a straightforward format and simple calculation process. A simple description of the proposed bridge was introduced. The design formulae of the deflection were derived based on a simplified analytical plane truss model, which possessed hinge nodes and was subsequently simplified as two solid web beams during the theoretical derivation process. To validate the analytical model and formulae, numerical and experimental works were conducted and compared with the theoretical solutions. The results indicate that the analytical formulae provide higher deflection magnitudes with a difference of <1.5% compared with the experiments performed and <4.5% compared with the FE model used; the simplified plane truss is thus shown to be an effective analytical model for the derivation of deflection design formulae, which can conveniently calculate the deflection of the hybrid space truss bridge with satisfactory accuracy.

  16. Automatically produced FRP beams with embedded FOS in complex geometry: process, material compatibility, micromechanical analysis, and performance tests

    Science.gov (United States)

    Gabler, Markus; Tkachenko, Viktoriya; Küppers, Simon; Kuka, Georg G.; Habel, Wolfgang R.; Milwich, Markus; Knippers, Jan

    2012-04-01

    The main goal of the presented work was to evolve a multifunctional beam composed out of fiber reinforced plastics (FRP) and an embedded optical fiber with various fiber Bragg grating sensors (FBG). These beams are developed for the use as structural member for bridges or industrial applications. It is now possible to realize large scale cross sections, the embedding is part of a fully automated process and jumpers can be omitted in order to not negatively influence the laminate. The development includes the smart placement and layout of the optical fibers in the cross section, reliable strain transfer, and finally the coupling of the embedded fibers after production. Micromechanical tests and analysis were carried out to evaluate the performance of the sensor. The work was funded by the German ministry of economics and technology (funding scheme ZIM). Next to the authors of this contribution, Melanie Book with Röchling Engineering Plastics KG (Haren/Germany; Katharina Frey with SAERTEX GmbH & Co. KG (Saerbeck/Germany) were part of the research group.

  17. Building Materials

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ Building Materials Sub-council of CCPIT is the other sub-council in construction field. CCPIT Building Materials Sub-council (CCPITBM), as well as CCOIC Build-ing Materials Chamber of Commerce, is au-thorized by CCPIT and state administration of building materials industry in 1992. CCPITBM is a sub-organization of CCPIT and CCOIC.

  18. 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.

  19. FRP人行桥的人致振动特性研究%VIBRATION STUDY ON FRP FOOTBRIDGE UNDER HUMAN-INDUCED LOAD

    Institute of Scientific and Technical Information of China (English)

    金飞飞; 冯鹏; 叶列平

    2011-01-01

    As the new structural materials and long span footbridge being used these years, the vibration prob lem due to human-induced load has become a significant issue. Especially in regards to the light-weight FRP foot bridge , the weight of crowd can' t be overlooked, thus when analyzing the dynamic response of FRP footbridge, it' s necessary to consider the influence of crowd. In this paper, the human body internal driven force is introduced and derived, then the vertical coupling vibration equations are established. With the numerical analysis method, the dy namic response of an actual FRP cable-stayed footbridge is analyzed under different pedestrian flows, and the effect of reducing the dynamic response by paving a layer of concrete is also analyzed. All theoretical analysis shows that the FRP cable-stayed footbridge can meet the requirement of dynamic performance under human-induced load.%近年来随着新材料以及大跨度人行天桥的不断出现,由行人行走引起的振动问题日渐显著.尤其在轻质FRP人行天桥中,行人质量相对桥梁本身质量不可忽略,在计算FRP人行天桥动力响应时,需要考虑行人带来的影响.本文通过引入并推导了行人人体驱动力,建立起行人与人行天桥之间的耦合竖向振动方程.利用数值分析方法分析了一座实际FRP斜拉人行桥在不同行人通行量下的动力响应,并分析了上铺混凝土面层对改善动力响应的效果.理论分析表明,该FRP斜拉桥可满足对人行天桥动力性能的要求.

  20. Cálculo en agotamiento de secciones de fábrica reforzadas a flexión con láminas de FRP

    Directory of Open Access Journals (Sweden)

    Martínez, S.

    2015-12-01

    Full Text Available Masonry structures can hardly resist tensile loads. For this reason these structures are vulnerable to accidental actions, such as earthquakes, or when they suffer damage that change their geometry conditions, for instead, due to differential soil settlements. This paper presents an ultimate limit state method for checking FRP-strengthened unreinforced masonry sections. The method is similar to the one used for reinforced concrete members, but it is adapted to masonry and FRP laminates particularities. In this proposal a bilinear strength-strain relationship is used and the FRP design strain is limited to take into account different aspects which cause the plate can’t reach its ultimate strength. In particular, it is proposed a “bond reduction factor”, derived from a large bending test database.Las estructuras de fábrica apenas tienen capacidad para resistir tracciones lo que las hace vulnerables ante acciones desestabilizantes de tipo accidental, como terremotos, o cuando sufren daños que alteran su geometría, por ejemplo, por asientos diferenciales. En este trabajo se presenta un método para la comprobación en agotamiento de secciones de fábrica reforzadas a flexión con láminas de FRP. Está basado en el procedimiento de cálculo de la capacidad resistente de secciones de hormigón pero adaptado a las particularidades y condicionantes de las fábricas reforzadas. En esta propuesta se utiliza un diagrama de cálculo tensión deformación de la fábrica de tipo bilineal y se limita la deformación de cálculo del refuerzo teniendo en consideración ciertos aspectos que provocan que no pueda desarrollar toda su resistencia. En concreto, se propone un «coeficiente reductor por adherencia» que se determina a partir de una amplia base de datos con ensayos de flexión.

  1. Fiber Optic Assessment of Damage in Frp Strengthened Structures%光纤传感器测量FRP加固结构的损伤

    Institute of Scientific and Technical Information of China (English)

    赵鸣; 赵鸿; 赵阳; F.Ansari

    2002-01-01

    A distributed fiber optic sensor is developed for condition monitoring of civil infrastructure sys-tems. The fiber optic sensor is especially useful in applications involving structures strengthened by fiberreinforced polymer (FRP) composites. The sensor principles are simple and therefore, practical for detec-tion of cracks, debonding and deformation measurements. Structural monitoring capability of the sensorwas evaluated through experiments with cracked reinforced concrete beams strengthened by way of CFRP(Carbon Fiber Reinforced Polymer) fabrics. Sensor principle and experimental results are presented anddiscussed.

  2. FRP衬里树脂重防腐之缺陷及解决办法%Defects&Solutions of FRP Lining Resin Heavy-duty

    Institute of Scientific and Technical Information of China (English)

    欧阳自强

    2012-01-01

      This paper systematically summarizes problems and fabrication quality defects of the thermosetting resin, particularly unsaturated polyester resins and vinyl ester resin in anti-corrosion FRP Lining engineer, then analyzes their reasons and put forward solutions.%  本文系统总结了热固性树脂,尤其是不饱和聚酯树脂和乙烯基酯树脂在制作重防腐玻璃钢衬里时遇到的问题及施工质量缺陷,分析其原因,提出解决对策。

  3. 防腐混凝土梁长期力学性能试验研究%THE STUDY ON CREEP BEHAVIOR OF FRP REBAR REINFORCED ANTISEPTIC CONCRETE BEAM

    Institute of Scientific and Technical Information of China (English)

    余启明; 吴卫国; 李军向; 晏石林

    2009-01-01

    FRP rural resin concrete which has extensive application prospect is a kind of anti-corrosive new en-gineering material. Although it's stronger in compression than cementitious concrete, its tension behavior is weak, the reinforcement of polymer concrete beams in the tension zone with puhruded profiles made of resin and glass fibers are a good compromise between strength and stiffness. In this paper, firstly the experience has performed about the bending and creep characteristic of non-FRP reinforced furan resin concrete beam and FRP reinforced furan concrete beam, the creep curves are gained of the beams under different loads by four-point bending tests method, analysis is carried on the viscoelasticity nature, the result shows that FRP not only enhances the furan resin concrete beam's ini-tial stiffness and strength, but also obviously reduces the creep strain of the beam. Secondly the creep model varia-bles are determined through the least square method, the bending creep power law model are separately built of non-FRP reinforced furan resin concrete beam and FRP reinforced furan concrete beam,which is the basis of estimation of material's long term mechanics performance, and also has important project practical value to the FRP furan resin concrete structure design.%玻璃钢(FRP)筋防腐混凝土是一种强度高、全方位耐腐蚀的新型工程材料,具有十分广泛的应用前景.本文先对防腐混凝土梁采用四点弯曲试验方法,对FRP筋加强混凝土梁的弯曲长期力学特性进行了试验研究与分析,得到了梁在不同荷载水平作用下的蠕变曲线.结果表明,FRP筋不仅提高了防腐混凝土梁的初始刚度和强度,且明显降低了梁的蠕变变形.最后,运用最小二乘法确定蠕变模型参数,分别建立了防腐混凝土粱和FRP筋加强防腐混凝土梁的弯曲蠕变幂律模型,为估计材料的长期力学性能提供依据,对FRP筋防腐混凝土结构设计具有重要的价值.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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...

  10. 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

  11. 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

  12. 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.

  13. Economic & technological equations and characteristic analyses for inshore FRP trawl boats%近海玻璃钢拖网渔船的技术经济方程和特征分析

    Institute of Scientific and Technical Information of China (English)

    陶冶; 奚海波; 王建彬; 于红; 吴俊峰; 贾复

    2015-01-01

    根据近海玻璃钢( FRP)拖网渔船缺乏技术经济论证数学模型的问题,建立了针对玻璃钢拖网渔船的技术经济方程,对方程中的油耗、经济寿命、造价、维修费用、折旧费等经济影响因素进行了分析比较。结果表明:多数指标变量对玻璃钢渔船的经济性是有利的,仅造价指标具有负面影响,本研究中建立的技术经济方程有效地满足了玻璃钢最优船型论证的需要,可为船舶建造、捕捞管理提供计算及指导依据。%In view of the problem of lack of the math model for the evaluation of optimum fiber reinforced plastics ( FRP) trawl boats, series of economic & technological equations were in this paper proposed, and comparatively analyzed the factors influencing economy of FRP trawls boat, such as fuel consumption, economic life-span, cost, maintain expense, and depreciation cost were analysed comparatively. The results showed that most of the target variable is good for the economy of the FRP fishing trawler, only the cost showing a negative influence. These equa-tions can effectively meet the needs of the FRP optimal ship type evaluation, and provide the basis of the calculation for the construction, management and fishing department.

  14. 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.

  15. 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.

  16. 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.

  17. Building America

    Energy Technology Data Exchange (ETDEWEB)

    Brad Oberg

    2010-12-31

    IBACOS researched the constructability and viability issues of using high performance windows as one component of a larger approach to building houses that achieve the Building America 70% energy savings target.

  18. 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.

  19. 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.

  20. Solar building

    OpenAIRE

    Zhang, Luxin

    2014-01-01

    In my thesis I describe the utilization of solar energy and solar energy with building integration. In introduction it is also mentioned how the solar building works, trying to make more people understand and accept the solar building. The thesis introduces different types of solar heat collectors. I compared the difference two operation modes of solar water heating system and created examples of solar water system selection. I also introduced other solar building applications. It is conv...

  1. Solar heating and hot water system installed at Municipal Building complex, Abbeville, South Carolina

    Science.gov (United States)

    1979-01-01

    Information on the solar energy system installed at the new municipal building for the City of Abbeville, SC is presented, including a description of solar energy system and buildings, lessons learned, and recommendations. The solar space heating system is a direct air heating system. The flat roof collector panel was sized to provide 75% of the heating requirement based on an average day in January. The collectors used are job-built with two layers of filon corrugated fiberglass FRP panels cross lapped make up the cover. The storage consists of a pit filled with washed 3/4 in - 1 1/2 in diameter crushed granite stone. The air handler includes the air handling mechanism, motorized dampers, air circulating blower, sensors, control relays and mode control unit. Solar heating of water is provided only those times when the hot air in the collector is exhausted to the outside.

  2. Modelling of Hybrid Materials and Interface Defects through Homogenization Approach for the Prediction of Effective Thermal Conductivity of FRP Composites Using Finite Element Method

    Directory of Open Access Journals (Sweden)

    C. Mahesh

    2013-01-01

    Full Text Available Finite element method is effectively used to homogenize the thermal conductivity of FRP composites consisting of hybrid materials and fibre-matrix debonds at some of the fibres. The homogenized result at microlevel is used to determine the property of the layer using macromechanics principles; thereby, it is possible to minimize the computational efforts required to solve the problem as in state through only micromechanics approach. The working of the proposed procedure is verified for three different problems: (i hybrid composite having two different fibres in alternate layers, (ii fibre-matrix interface debond in alternate layers, and (iii fibre-matrix interface debond at one fibre in a group of four fibres in one unit cell. It is observed that the results are in good agreement with those obtained through pure micro-mechanics approach.

  3. Eigenvalue Buckling Analysis of FRP Transmission Tower%玻璃钢输电塔中稳定构件布置形式的研究

    Institute of Scientific and Technical Information of China (English)

    屈成忠; 朱瑞玲; 王孙宝

    2013-01-01

    以通用设计中的110 kV输电塔为计算模型,研究了将玻璃钢材料应用于输电塔上能满足结构稳定性的构件布置形式,采用特征值屈曲分析对风荷载作用下不同塔腿和塔身形式的输电塔进行了有限元计算.结果表明,主材用角钢、其他构件用玻璃钢的输电塔结构和改变塔腿形式或再进一步将塔身下半部改为具有水平材的双腹杆形式均能满足结构稳定性要求.%According to the 110 kV power transmission towers in general design, the stable form of transmission tower used FRP components was researched. Considering the influences of the different arrangement of tower legs and tower body on the stability of structure, the finite element calculation of transmission tower under wind load was carried out through the eigenvalue buckling analysis. It is concluded that the transmission tower whose principal material are angle steel and others are FRP can meet the requirements of the structure stability through modifying the form of legs or the first body to become the double ventral pole form with a level pole.

  4. 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

  5. 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.

  6. 考虑负荷类型及停电损失的负荷恢复策略优化%Optimization of load recovery plans considering different load types and outage cost

    Institute of Scientific and Technical Information of China (English)

    李亚男; 顾雪平; 钟慧荣

    2012-01-01

    The full load recovery in the late restoration process of a blackout power system is investigated to build an optimization method for determining the load restoration plans after the network reconfiguration. By dividing the full load recovery process into several sequential restoration stages, the maximized amount of the load restoration in each stage is taken as the objective function, with consideration of the diversity of load types and outage cost at each load bus, the optimization of the load restoration is treated as a 0 ~ 1 knapsack problem, and the backtracking algorithm is used to Bolve it. The proposed approach to determine load restoration plans can make a balance between the quick recovery of the important loads and minimization of the outage cost. The IEEE-30 test system is employed to verify the effectiveness of the proposed method and to assess the difference of load restoration for the different reconfigured networks.%研究大停电后系统恢复后期的负荷全面恢复问题,提出了网架重构结束后负荷恢复策略的优化方法.通过将负荷全面恢复过程划分为几个次序进行的恢复阶段,以每阶段的可投入负荷量最大为目标函数,考虑各节点待恢复负荷的类型差异和停电损失的不同,将负荷恢复优化问题转化成一个0-1背包问题,并采用回溯算法进行求解.提出的负荷恢复策略制定方法同时兼顾了重要负荷的快速恢复及减小系统停电损失两方面的要求.以IEEE30节点系统为算例,验证了提出的恢复方法的有效性,并比较了不同网络重构方案下负荷恢复时间和停电损失的差异性.

  7. Laboratory Building.

    Energy Technology Data Exchange (ETDEWEB)

    Herrera, Joshua M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-03-01

    This report is an analysis of the means of egress and life safety requirements for the laboratory building. The building is located at Sandia National Laboratories (SNL) in Albuquerque, NM. The report includes a prescriptive-based analysis as well as a performance-based analysis. Following the analysis are appendices which contain maps of the laboratory building used throughout the analysis. The top of all the maps is assumed to be north.

  8. Laboratory Building

    Energy Technology Data Exchange (ETDEWEB)

    Herrera, Joshua M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-03-01

    This report is an analysis of the means of egress and life safety requirements for the laboratory building. The building is located at Sandia National Laboratories (SNL) in Albuquerque, NM. The report includes a prescriptive-based analysis as well as a performance-based analysis. Following the analysis are appendices which contain maps of the laboratory building used throughout the analysis. The top of all the maps is assumed to be north.

  9. 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

  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. Building Languages

    Science.gov (United States)

    ... Training Manually Coded English (MCE) Natural Gestures Speech Speech Reading (Lip Reading) Even though American Sign Language (ASL) is not a building block, it is sometimes used together with one or more building blocks. Close Information For... Media Policy Makers File Formats Help: How do I view ...

  12. 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.).

  13. 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...

  14. Research advance of near-surface mounted fiber-reinforced polymer to concrete%表层嵌贴FRP-混凝土黏结加固研究进展

    Institute of Scientific and Technical Information of China (English)

    童谷生; 蔡少杰

    2014-01-01

    Near-surface mounted(NSM)fiber-reinforced polymer(FRP)reinforcement is one of the latest and most promising strength-ening techniques for reinforced concrete(RC)structures.Research on this topic mainly focused on the bonding mechanism and the flexural strengthening.The paper presents bond mechanics of NSM FRP bars/strips to concrete including the bond test methods ,effect of test vari-ables,bond failure modes,analytical modeling,local bond shear stress-slip relationship.It provides a critical review of existing research in this area,identifies gaps of knowledge,and outlines directions for further research.%表层嵌贴FRP修复加固混凝土结构是一种富有前景的新型技术,目前该技术领域的研究主要集中在黏结机理和抗弯加固两方面。论述表层嵌贴FRP-混凝土的试验方法、主要控制参数、破坏模式、黏结机理、界面黏结滑移本构关系等。最后,对目前国内外表层嵌贴FRP-混凝土黏结性能的研究现状进行探讨,希望为表层嵌贴FRP加固技术的进一步研究发展提供方向。

  15. 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.

  16. 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.

  17. [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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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

  3. 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.

  4. 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.

  5. Specific in vivo binding in the rat brain of [{sup 18}F]RP 62203: A selective 5-HT{sub 2A} receptor radioligand for positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Besret, Laurent; Dauphin, Francois; Huard, Cecile; Lasne, Marie-Claire; Vivet, Richard; Mickala, Patrick; Barbelivien, Alexandra; Baron, Jean-Claude

    1996-02-01

    In vivo pharmacokinetic and brain binding characteristics of [{sup 18}F]RP 62203, a selective high-affinity serotonergic 5-HT{sub 2A} receptor antagonist, were assessed in the rat following intravenous injection of trace amount of the radioligand. The radioactive distribution profile observed in the brain 60 min after injection was characterized by greater than fourfold higher uptake in neocortex as compared to cerebellum (0.38 {+-} 0.07% injected dose/g, % ID/g and 0.08 {+-} 0.01 ID/g, respectively), consistent with in vivo specific binding to the 5-HT{sub 2A} receptor. Furthermore, specific [{sup 18}F]RP 62203 binding significantly correlated with the reported in vitro distribution of 5-HT{sub 2A} receptors, but not with known concentration profiles of dopaminergic D{sub 2} or adrenergic {alpha}{sub 1} receptors. Finally, detectable specific binding was abolished by pretreatment with large doses of ritanserin, a selective 5-HT{sub 2A} antagonist, which resulted in uniform uptakes across cortical, striatal and cerebellar tissues. Thus, [{sup 18}F]RP 62203 appears to be a promising selective tool to visualize and quantify 5-HT{sub 2A} brain receptors in vivo with positron emission tomography.

  6. 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.

  7. 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).

  8. Building Inclusion

    NARCIS (Netherlands)

    Jeanet Kullberg; Isik Kulu-Glasgow

    2009-01-01

    The social inclusion of immigrants and ethnic minorities is a central issue in many European countries. Governments face challenges in ensuring housing for immigrants, delivering public services, promoting neighbourhood coexistence and addressing residential segregation. The Building Inclusion proje

  9. Dimensionamiento del refuerzo a flexión con laminados de polímeros reforzados con fibras (FRP evitando su desprendimiento prematuro

    Directory of Open Access Journals (Sweden)

    Oller, E.

    2013-12-01

    Full Text Available According to the available experimental research related to structures flexurally strengthened by bonding fiber reinforced polymer (FRP laminates, the laminate debonds in a brittle manner in most tests. This debonding failure usually initiates in the most loaded regions due the effect of intermediate cracks (intermediate crack debonding. From the beginning of this technique, several models have been developed to avoid this premature failure. However, some of them present a significant scatter in relation to the experimental data. This paper presents a comparative analysis of the existing formulations through a database of tests compiled by the authors. Afterwards, a design procedure based on a shear-bending moment interaction diagram related to intermediate crack debonding is presented. This interaction diagram depends on the maximum shear force between crack discontinuities. Finally, the proposed method is compared to the rest of the models obtaining satisfactory results when predicting the failure load.La investigación experimental de elementos de hormigón reforzados a flexión mediante la adhesión de laminados de polímeros reforzados con fibras (FRP muestra que en la mayor parte de ensayos, el laminado se desprende de forma prematura iniciándose normalmente el fallo en las regiones más solicitadas debido al efecto de las fisuras intermedias. Desde los inicios de esta técnica de refuerzo, se han desarrollado modelos para evitar este tipo de rotura, la mayoría de los cuales presentan una dispersión considerable comparando sus resultados con los experimentales. En este artículo se presenta un análisis comparativo de diferentes formulaciones existentes a partir de una base de datos de ensayos recopilada por los autores. Posteriormente, se propone un método de dimensionamiento basado en un diagrama de interacción cortante-flexión asociado al desprendimiento del refuerzo, que depende de la máxima fuerza rasante transmitida entre

  10. Sustainable Buildings

    DEFF Research Database (Denmark)

    Tommerup, Henrik M.; Elle, Morten

    The scientific community agrees that: all countries must drastically and rapidly reduce their CO2 emissions and that energy efficient houses play a decisive role in this. The general attitude at the workshop on Sustainable Buildings was that we face large and serious climate change problems...... that need urgent action. The built environment is an obvious area to put effort into because of the large and cost-effective energy saving potential and potential for Renewable Energy-based supply systems for buildings....

  11. Analyzing Design Heating Loads in Superinsulated Buildings

    Energy Technology Data Exchange (ETDEWEB)

    Arena, Lois [Consortium for Advanced Residential Buildings, Norwalk, CT (United States)

    2015-06-01

    Super-insulated homes offer many benefits including improved comfort, reduced exterior noise penetration, lower energy bills, and the ability to withstand power and fuel outages under much more comfortable conditions than a typical home. While these homes aren't necessarily constructed with excessive mass in the form of concrete floors and walls, the amount of insulation and the increase in the thickness of the building envelope can lead to a mass effect, resulting in the structures ability to store much more heat than a code built home. This results in a very low thermal inertia making the building much less sensitive to drastic temperature swings thereby decreasing the peak heating load demand. During the winter of 2013/2014, CARB monitored the energy use of three homes in climate zone 6 in an attempt to evaluate the accuracy of two different mechanical system sizing methods for low load homes. Based on the results, it is recommended that internal and solar gains be included and some credit for thermal inertia be used in sizing calculations for super insulated homes.

  12. Our Buildings, Ourselves.

    Science.gov (United States)

    Roodman, David Malin; Lenssen, Nicholas

    1994-01-01

    Reviews in detail environmental impacts associated with buildings. Discusses building construction, internal environments, building life spans, building materials, protection from climate, and amenities. (LZ)

  13. FGF23、MEPE和sFRP4在肿瘤性骨软化症发病机制中的作用%Roles of FGF23,MEPE and sFRP4 in the pathogenesis of tumor induced osteomalacia

    Institute of Scientific and Technical Information of China (English)

    姜艳; 夏维波; 孟迅吾

    2009-01-01

    肿瘤性骨软化症(TIO)是由于肿瘤引起肾脏排磷增加,所造成的获得性低血磷骨软化-症.近来研究显示,肿瘤分泌的体液因子(如调磷因子)可以影响体内磷的平衡,而成纤维细胞牛长因子-23(FGF-23)、细胞外基质磷酸糖蛋白(MEPE)和分泌型卷曲相关蛋白(sFRP)4可能就是调磷因子.它们通过抑制肾小管上皮细胞磷的回吸收,抑制肾脏1,α羟化酶的活性,从而调节血磷,使患者血磷降低,尿磷增多,血1,25(OH)2D3水平降低或正常,从而参与TIO的发生.%Tumor induced osteomalacia(TIO) is an acquired hypophosphatemie syndrome caused y tumors.Experimental evidence suggests that the biochemical and skeletal defects are caused by humeral factors(phosphatonins)from the tumor.The potential candidates for phosphatonins,such as fibroblast growth factor-23(FGF-23),matrix extracellular phosphoglyeoprotein(MEPE)and secreted frizzled related protein 4(sFRP4)are characterized by impaired renal tubular reabsorption of phosphate,and inhibited l,α hydroxylase.They induce low levels of serum phosphate and 1,25-dihydroxyvitamin D3,therefore,play important roles in the pathogenesis of TIO.

  14. 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.

  15. 工程结构用FRP筋的力学性能%Mechanics Performance of FRP Tendons Used in Engineering Structure

    Institute of Scientific and Technical Information of China (English)

    朱虹; 钱洋

    2006-01-01

    通过分析工程结构用纤维增强塑料(FRP)筋的组成和物理力学性能特点,对比FRP筋性能和钢筋性能的不同之处,指出了FRP筋在工程结构中的适用性和应用前景.通过试验研究,分析了局部弯折对芳纶纤维增强塑料(AFRP)筋极限抗拉强度、加载速率和加载历史对编织型芳纶纤维筋(FiBRA)型AFRP筋弹性模量,以及应力水平对FiBRA型AFRP筋松弛率的影响,建立了规格为FA11的FiBRA型AFRP筋的松弛率计算公式.结果表明,局部弯折可能导致FRP筋的极限抗拉强度下降,FiBRA型AFRP筋编织状的成型特征造成其弹性模量在张拉过程中是渐趋稳定的,并且造成其总松弛量较大,工程应用时需充分考虑这些因素.

  16. Competence Building

    DEFF Research Database (Denmark)

    Borrás, Susana; Edquist, Charles

    on the one hand, and the real world of innovation policy-making on the other, typically not speaking to each other. With this purpose in mind, this paper discusses the role of competences and competence-building in the innovation process from a perspective of innovation systems; it examines how governments...... and public agencies in different countries and different times have actually approached the issue of building, maintaining and using competences in their innovation systems; it examines what are the critical and most important issues at stake from the point of view of innovation policy, looking particularly...

  17. Building Procurement

    DEFF Research Database (Denmark)

    Andersson, Niclas

    2007-01-01

    despite this excellent book, the knowledge, expertise, well-articulated argument and collection of recent research efforts that are provided by the three authors will help to make project success less elusive. The book constitutes a thorough and comprehensive investigation of building procurement, which......, which gives the book a challenging contribution to the existing body of knowledge....

  18. Building Sandcastles

    DEFF Research Database (Denmark)

    Jensen, Steffen Moltrup Ernø; Korsgaard, Steffen; Shumar, Wes

    of entrepreneurship education. Our theoretical and methodological approach builds on Actor-Network Theory. The empirical settings of our study consist of two entrepreneurship courses which differ in terms of temporal extension and physical setting. Data is collected using observation and interview techniques. Our...

  19. Building Partnerships.

    Science.gov (United States)

    Kisner, Mary J.; And Others

    1997-01-01

    Defines school-business partnerships and reviews changes in such partnerships over the past 25 years. Provides steps to building effective partnerships for school-to-work activities: review the school's mission; select partners that will bring strength to the relationship; set clearly defined, realistic goals; maintain the partnership; and…

  20. 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.

  1. 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.

  2. 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.

  3. Shaking Table Tests Validating Two Strengthening Interventions on Masonry Buildings

    Science.gov (United States)

    De Canio, Gerardo; Muscolino, Giuseppe; Palmeri, Alessandro; Poggi, Massimo; Clemente, Paolo

    2008-07-01

    numerical and experimental research has been carried out, aimed at validating two different strengthening interventions on masonry buildings: (i) the substitution of the existing roof with timber-concrete composite slabs, which are able to improve the dynamic behaviour of the structure without excessively increase the mass, and (ii) the reinforcement of masonry walls with FRP materials, which allow increasing both stiffness and strength of the construction. The experimental tests have been performed on a 1:2 scale model of a masonry building resembling a special type, the so-called "tipo misto messinese", which is proper to the reconstruction of the city of Messina after the 1783 Calabria earthquake. The model, incorporating a novel timber-concrete composite slab, has been tested on the main shaking table available at the ENEA Research Centre "Casaccia," both before and after the reinforcement with FRP materials. Some aspects related to the definition of the model and to the selection of an appropriate seismic input will be discussed, and numerical results confirming the effectiveness of the interventions mentioned above will be presented.

  4. Building Letters

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Cabinet是种十分吸引人却很简单的衬线字体,是由一名匿名字体设计师专门为Building Letters最新的资金筹集活动所设计的。这个Building Letters包中包含一个CDROM,有32种字体,以及一本专门设计的杂志和两张由Eboy和Emigre所设计的海报。字体光盘样例是由世界顶级的字体设计师们设计的.

  5. Building Bridges

    DEFF Research Database (Denmark)

    The report Building Bridges adresses the questions why, how and for whom academic audience research has public value, from the different points of view of the four working groups in the COST Action IS0906 Transforming Audiences, Transforming Societies – “New Media Genres, Media Literacy and Trust...... in the Media”, “Audience Interactivity and Participation”, “The Role of Media and ICT Use for Evolving Social Relationships” and “Audience Transformations and Social Integration”. Building Bridges is the result of an ongoing dialogue between the Action and non-academic stakeholders in the field of audience...... Belgrade), Leo Pekkala (Finnish Centre for Media Education and Audiovisual Media/MEKU), Julie Uldam (Network on Civic Engagement and Social Innovation) and Gabriella Velics (Community Media Forum Europe)....

  6. Building economics

    DEFF Research Database (Denmark)

    Pedersen, D.O.(red.)

    Publikationen er på engelsk. Den omfatter alle indlæg på det fjerde internationale symposium om byggeøkonomi, der blev arrangeret af SBI for det internationale byggeforskningsråd CIB. De fem bind omhandler: Methods of Economic Evaluation, Design Optimization, Ressource Utilization, The Building...... Market og Economics and Technological Forecasting in Construction. Et indledende bind bringer statusrapporter for de fem forskningsområder, og det sidste bind sammenfatter debatten på symposiet....

  7. CURRENT STATUS AND PROSPECTS OF STUDY ON LOW VELOCITY IMPACT DAMAGED CHARACTERIZATION OF FIBER-REINFORCED COMPOSITE LAMINATES%FRP 层合板低速冲击损伤特性研究现状与展望

    Institute of Scientific and Technical Information of China (English)

    张颖军; 梅志远; 朱锡

    2011-01-01

    纤维增强复合材料层合板(FRP)由于具有比强度高、比模量高、可设计性强等特性,在工程领域得到越来越广泛的应用.但是低速冲击造成的损伤对层合板力学性能的影响非常显著,导致其强度和刚度下降.本文针对近年来纤维增强复合材料层合板低速冲击作用下的损伤研究进行了综述和回顾,重点介绍了试验研究方法、模拟计算研究方法、FRP 层合板损伤性能表征方法,并对有待于进一步研究的问题进行了展望.%Fiber-reinforced composite laminates have been widely used in engineering area because of its special properties, such as high specific strength, high specific stiffness and excellent designability. But the effect of damage caused by low velocity impact on the FRP is remarkable, which can reduce the strength and stiffness. The study on damage of fiber-reinforced composite laminates under low velocity impact in recent years is summarized and reviewed in this article. The main contents of the article are as follows: experimental methods, simulating and calculating methods, characterization of composites damage, and some problems to be studied in the future are proposed.

  8. 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.

  9. Development of a Novel Elastic Acrylic Polyurethane FRP Primers%新型弹性丙烯酸聚氨酯玻璃钢底漆的研制

    Institute of Scientific and Technical Information of China (English)

    李儒剑; 孟兆荣; 周升; 曾凡辉; 陈立斌

    2011-01-01

    Fiberglass reinfored plastic ( FRP) primers was prepared from elastic acrylic resin & HDI polymer as film - forming materials, whose various properties met the designed requirements. It was found that different HDI polymer curing agents with various functionality affected primers' mechanical property and workability, and slighthly affected primers' chemical resistance and durability. High molecular weight block copolymer dispersant with pigment - compatible groups was better than amino polyester dispersant for primers' grinding and storage. Organic modified bentonite and fumed silica both had more contributions to improvement of film thickness than polyethylene wax slurry did.%以弹性丙烯酸树脂和HDI聚合物为成膜物制得双组分玻璃钢专用底漆,经测试其各项性能达到设计要求.研究发现:不同官能度的HDI聚合物固化剂对涂料的力学性能和施工性能有影响,但对耐化学品和耐久性影响不大;带亲颜料基团的高分子嵌段共聚物分散剂对漆料的研磨效率和贮存稳定性贡献要大于氨基聚酯型分散剂;有机改性膨润土和气相二氧化硅比聚乙烯蜡浆对涂料喷涂施工厚度提高效果要明显.

  10. Single-step purification of recombinant proteins using elastin-like peptide-mediated inverse transition cycling and self-processing module from Neisseria meningitides FrpC.

    Science.gov (United States)

    Liu, Wen-Jun; Wu, Qian; Xu, Bi; Zhang, Xin-Yu; Xia, Xiao-Li; Sun, Huai-Chang

    2014-06-01

    Purification of recombinant proteins is a major task and challenge in biotechnology and medicine. In this paper we report a novel single-step recombinant protein purification system which was based on elastin-like peptide (ELP)-mediated reversible phase transition and FrpC self-processing module (SPM)-mediated cleavage. After construction of a SPM-ELP fusion expression vector, we cloned the coding sequence for green fluorescent protein (GFP), the Fc portion of porcine IgG (pFc) or human β defensin 3 (HBD3) into the vector, transformed the construct into Escherichia coli, and induced the fusion protein expression with IPTG. The target-SPM-ELP fusion proteins GFP-SPM-ELP, Fc-SPM-ELP and HBD3-SPM-ELP were expressed in a soluble form and efficiently purified from the clarified cell extracts by two rounds of inverse transition cycling (ITC). Under the optimized conditions, the SPM-mediated cleavage efficiencies for the three fusion proteins ranged from 92% to 93%. After an additional round of ITC, the target proteins GFP, pFc and HBD3 were recovered with purities ranging from 90% to 100% and yields ranging from 1.1 to 36mg/L in shake flasks. The endotoxin levels in all of the three target proteins were proteins were functionally active with the expected molecular weights. These experimental results confirmed the high specificity and efficiency of SPM-mediated cleavage, and suggested the applicability of SPM-ELP fusion system for purification of recombinant proteins.

  11. 预制夹芯保温墙体FRP连接件抗拔性能试验研究%PULL-OUT TESTS FOR EVALUATIONS OF ANTI-PULLING BEHAVIOR OF FRP CONNECTORS IN PRECAST SANDWICH INSULATION WALL PANELS

    Institute of Scientific and Technical Information of China (English)

    薛伟辰; 杨佳林; 王君若

    2012-01-01

    预制夹芯保温墙体是集承载与保温一体化的新型预制保温墙体.该墙体由内外叶钢筋混凝土板、中间保温层及纤维增强塑料(FRP)连接件组成,其中FRP连接件是连接内外叶钢筋混凝土板的关键部件,其受力性能直接影响墙体的安全性.本文以上海市某安居工程为背景,基于拔出试验对FRP连接件的抗拔承载力、破坏形态、荷载-滑移关系及荷载-应变关系等进行了较为系统的研究.研究表明,试件均发生了混凝土劈裂破坏;试件的抗拔承载力为23.5kN,为抗拔荷载设计值的14.3倍,满足工程设计要求,并具有较大的安全储备.最后,提出了预制保温墙体FRP连接件的抗拔承载力计算方法.%Precast sandwich insulation wall panel is a new type of insulation wall which performs well both in structural bearing and thermal insulation. This kind of wall is consisted of internal and external concrete wythes, insulating layers and the key component-FRP connectors, which ties two concrete wythes together to provide a distributed fastening system. Taking the model from a practical project in Shanghai as a reference, a series of tests including three pull-out specimens, with emphasis on FRP connectors' pull-out capacity, failure pattern and load-slip curve etc. , were presented. All the tests were terminated by the concrete fracture, and the average pull-out capacity of the connectors was 23. 5kN, about 14. 3 times of the design pull-out load. This means the connector could meet the requirements of the design in the practical project, and has a great safety margin as well. In addition, the calculation method to compute the pull-out capacity of FRP connectors in precast concrete sandwich wall is proposed.

  12. 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.

  13. 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.

  14. 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%.

  15. Anti-cor osion Performance of FiberglassR einforced Plastic (FRP) under Stimulta ed Conditions of Chimney in Power Plant%模拟火电烟囱工况下乙烯基酯树脂基FRP 的腐蚀性研究

    Institute of Scientific and Technical Information of China (English)

    冯敏; 梁高; 王剑平; 张学双

    2014-01-01

    本文利用含1500 ppm H2 SO4、250 ppm H2 SO3以及250 ppm HCl的混合溶液在65℃加热浸泡试样,再在180℃、200℃高温烘烤试样的实验方法来模拟火电玻璃钢烟囱在运行过程中的腐蚀情况,研究用于火电玻璃钢烟囱设备生产的2种乙烯基酯树脂901和907与相应的纤维增强材料组合的复合材料的耐受性能。结果表明:试样的空泡和分层随实验周期的延长而加剧,空泡和分层的程度与选用的树脂及纤维增强材料的种类相关;酚醛环氧乙烯基酯树脂907比溴化双酚A型环氧乙烯基酯树脂901有更好的耐蚀耐温性能;碳纤维与玻璃纤维复合使用比单纯使用玻璃纤维(C型)的试样具有更好的耐分层和空泡的性能。%Anti-Corrosion performance of specimen made of two types of resin 901 and 907 composited with different types of veil were studied under stimulated conditions which consist of 65℃ soaking in a solution contain 1 500 ppm H2 SO4 ,250 ppm H2 SO3 and 250 ppm HCl and 180℃,200℃baking.Results show that blistering appears to have resulted from a combination of time of exposure to the chemical solution ,the number of shock cycles ,the number and type of veils ,and the thermal shock temperature conditions;FRP based on brominated novolac epoxy vinyl ester resin appears to have better re-sistance to the degradation than FRP based on brominated epoxy vinyl ester resin .Also,a combination of carbon and C-glass veil appeared to perform better than a single C-glass veil alone .

  16. MYCELIUM BUILDING

    OpenAIRE

    Jondelius, Olof

    2015-01-01

    This work is looking in to what possibilites and restrictions comes with using mycelium as a building material for a small house. It includes reasoning around solutions for some of the problems and presenting some ideas of how to use some of the materials properties in your favor. A general background of why we need to start look in to alternative materials for all petroleum materials are presented. Det här arbetet har varit inriktat på att se vilka möjligheter samt begränsningar det skul...

  17. FRP加固RC梁界面疲劳损伤红外检测分析%Analysis of Interfacial Fatigue Behavior of RC Beams Strengthened with FRP Based on Infrared Thermography

    Institute of Scientific and Technical Information of China (English)

    邓江东; 黄培彦; 宗周红

    2010-01-01

    FRP-混凝土界面剥离损伤的探测是界面力学分析的一个难点.基于三个标准试件探讨了红外检测方法对FRP-混凝土界面剥离探测的精度、可行性以及剥离判断的标准,并对常幅疲劳荷载下FRP加固钢筋混凝土(RC)梁界面的疲劳行为进行了跟踪记录,分析了界面的疲劳破坏过程.试验结果表明,FRP加固RC梁界面存在初始的未粘结区,在疲劳加载的初期界面剥离快速增加,随后在大部分疲劳寿命期内保持稳定,在最后数千次加载循环内界面损伤失稳发展导致整个加固构件的破坏.文中基于红外数据给出了每个阶段的疲劳加载次数和界面剥离损伤的面积.

  18. Application of FRP Wrapped Tanks to Anti-corrosion of Nonferrous Metallurgy in Jinchuan%玻璃钢缠绕贮罐在金川有色冶金生产中的应用

    Institute of Scientific and Technical Information of China (English)

    吴培德

    2011-01-01

    The fundamental using condition, manufacturing process, structure and properties of glass fiber reinforced plastics(FRP) wrapped tanks are introduced, and the application of 100 m3, 200 m3, 270 m3 and 400 m3 FRP wrapped tanks to non-ferrous metallurgical industry in Jinchuan is introduced. This kind of tanks provides a new way to store up acid corrosion medium in non-ferrous metallurgical industry.%介绍了玻璃钢缠绕贮罐的使用条件、制造工艺、结构和性能等,以及100m3、200m3、270m3、400m3玻璃钢缠绕贮罐在金川有色冶金生产中的应用情况,该罐适合于有色湿法冶金工业酸性溶液腐蚀性介质的贮存。

  19. FRP加固框架节点的受力影响因素的数值模拟%Numerical simulation of the stress influence factors of FRP reinforcement frame joints

    Institute of Scientific and Technical Information of China (English)

    余登华; 黄志强; 梁芳

    2014-01-01

    FRP (Fiber Reinforced Plastics) fiber reinforced concrete frame joints was carried out a numerical analysis with finite element analysis software RFPA (Realistic Failure Process Analysis).It explored the effect of reinforcing from the concrete strength,fiber paste length and thickness.Finite element analysis results show that the reinforcement of the frame joints withstand the load and deformation capacity has improved signifi-cantly.%利用有限元分析软件RFPA (Realistic Failure Process Analysis)对FRP (Fiber Reinforced Plastics)纤维加固混凝土框架节点进行了数值分析,从混凝土强度、纤维布粘贴长度、纤维布粘贴厚度三方面探讨对加固效果的影响。有限元分析结果表明,加固了的框架节点所能承受的荷载和变形能力都有了显著提高。

  20. Existing buildings

    DEFF Research Database (Denmark)

    Gram-Hanssen, Kirsten

    2014-01-01

    their homes. These policy measures include building regulations, energy tax and different types of incentives and information dissemination. The conclusion calls for new and innovative policy measures to cope with the realities of renovations of owner-occupied houses and how energy efficiency improvement......This paper deals with the energy consumption of existing owner-occupied detached houses and the question of how they can be energy renovated. Data on the age of the Danish housing stock, and its energy consumption is presented. Research on the potential for energy reductions in the Danish housing...... sector is discussed, and it is shown that there is a huge potential for reductions. It is a well-known problem that even if there are relevant technical means and even if it is economically feasible, the majority of house owners do not energy renovate their homes. This paper intends to address what can...

  1. Integrating Responsive Building Elements in Buildings

    DEFF Research Database (Denmark)

    Haase, Matthias; Amato, Alex; Heiselberg, Per

    2006-01-01

    There is a global need for a more sustainable building development. About 50% of energy is used in buildings indicating that buildings provide a considerable potential for operational energy savings. Studies were conducted with the following objectives: to perform a state-of-the-art review...... energy strategies to develop guidelines and procedures for estimation of environmental performance of responsive building elements and integrated building concepts This paper introduces the ideas of this collaborative work and discusses its usefulness for Hong Kong and China. Special focus was put...... of responsive building elements, of integrated building concepts and of environmental performance assessment methods to improve and optimize responsive building elements to develop and optimize new building concepts with integration of responsive building elements, HVAC-systems as well as natural and renewable...

  2. Computational fluid dynamics analysis of a twisted airfoil shaped two-bladed H-Darrieus rotor made from fibreglass reinforced plastic (FRP

    Directory of Open Access Journals (Sweden)

    Rajat Gupta, Sukanta Roy, Agnimitra Biswas

    2010-11-01

    Full Text Available H-Darrieus rotor is a lift type device having two to three blades designed as airfoils. The blades are attached vertically to the central shaft through support arms. The support to vertical axis helps the rotor maintain its shape. In this paper, Computational Fluid Dynamics (CFD analysis of an airfoil shaped two-bladed H-Darrieus rotor using Fluent 6.2 software was performed. Based on the CFD results, a comparative study between experimental and computational works was carried out. The H-Darrieus rotor was 20cm in height, 5cm in chord and twisted with an angle of 30° at the trailing end. The blade material of rotor was Fiberglass Reinforced Plastic (FRP. The experiments were earlier conducted in a subsonic wind tunnel for various height-to-diameter (H/D ratios. A two dimensional computational modeling was done with the help of Gambit tool using unstructured grid. Realistic boundary conditions were provided for the model to have synchronization with the experimental conditions. Two dimensional steady-state segregated solver with absolute velocity formulation and cell based grid was considered, and a standard k-epsilon viscous model with standard wall functions was chosen. A first order upwind discretization scheme was adopted for pressure velocity coupling of the flow. The inlet velocities and rotor rotational speeds were taken from the experimental results. From the computational analysis, power coefficient (Cp and torque coefficient (Ct values at ten different H/D ratios namely 0.85, 1.0, 1.10, 1.33, 1.54, 1.72, 1.80, 1.92, 2.10 and 2.20 were calculated in order to predict the performances of the twisted H-rotor. The variations of Cp and Ct with tip speed ratios were analyzed and compared with the experimental results. The standard deviations of computational Cp and Ct from experimental Cp and Ct were obtained. From the computational analysis, the highest values of Cp and Ct were obtained at H/D ratios of 1.0 and 1.54 respectively. The

  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. 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。

  7. Building energy analysis tool

    Science.gov (United States)

    Brackney, Larry; Parker, Andrew; Long, Nicholas; Metzger, Ian; Dean, Jesse; Lisell, Lars

    2016-04-12

    A building energy analysis system includes a building component library configured to store a plurality of building components, a modeling tool configured to access the building component library and create a building model of a building under analysis using building spatial data and using selected building components of the plurality of building components stored in the building component library, a building analysis engine configured to operate the building model and generate a baseline energy model of the building under analysis and further configured to apply one or more energy conservation measures to the baseline energy model in order to generate one or more corresponding optimized energy models, and a recommendation tool configured to assess the one or more optimized energy models against the baseline energy model and generate recommendations for substitute building components or modifications.

  8. 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。

  9. Building America

    Energy Technology Data Exchange (ETDEWEB)

    Brad Oberg

    2010-12-31

    Builders generally use a 'spec and purchase' business management system (BMS) when implementing energy efficiency. A BMS is the overall operational and organizational systems and strategies that a builder uses to set up and run its company. This type of BMS treats building performance as a simple technology swap (e.g. a tank water heater to a tankless water heater) and typically compartmentalizes energy efficiency within one or two groups in the organization (e.g. purchasing and construction). While certain tools, such as details, checklists, and scopes of work, can assist builders in managing the quality of the construction of higher performance homes, they do nothing to address the underlying operational strategies and issues related to change management that builders face when they make high performance homes a core part of their mission. To achieve the systems integration necessary for attaining 40% + levels of energy efficiency, while capturing the cost tradeoffs, builders must use a 'systems approach' BMS, rather than a 'spec and purchase' BMS. The following attributes are inherent in a systems approach BMS; they are also generally seen in quality management systems (QMS), such as the National Housing Quality Certification program: Cultural and corporate alignment, Clear intent for quality and performance, Increased collaboration across internal and external teams, Better communication practices and systems, Disciplined approach to quality control, Measurement and verification of performance, Continuous feedback and improvement, and Whole house integrated design and specification.

  10. 喷射FRP加固震损钢筋混凝土柱抗震性能试验%Test of seismic performance of earthquake damaged reinforced concrete columns strengthened with sprayed FRP

    Institute of Scientific and Technical Information of China (English)

    谷倩; 董格; GETAHUNE Bitewlgn Mekonnen; 王翔

    2016-01-01

    Based on the tensile strength tests of 12 groups of 72 pieces of sprayed fiber reinforced polymer (FRP) specimens,the effects of factors such as fiber type,resin matrix material,fibers volume fraction,hybrid ratio of fi-bers and fiber length etc.on the properties such as tensile strength,elastic modulus and elongation at break etc.of sprayed FRP were investigated.The seismic performance of earthquake damaged reinforced concrete (RC)columns specimens strengthened with sprayed basalt fiber reinforced polymer (BFRP)and hybrid basalt-carbon fiber rein-forced polymer (BF-CFRP)was investigated by the quasi-static test of 8 RC columns,and the influences of the thickness of sprayed FRP layer,hybrid ratio of fibers,pre-damage degree of columns and the axial compression ratio of column etc.on the ultimate load capacity,lateral deformation resistance,degradation characteristics of stiffness and hysteresis properties of the strengthened specimens were analyzed.The test results show that the cooperative working performance of glass fiber and vinylester matrix is the best,and basalt fiber can be used as a favorable suc-cedaneum of glass fiber because of its excellent performance of high durability,good ductility and good cooperative working performance with vinylester matrix;hybrid basalt fibers with small amount of carbon fibers used as rein-forcement for resin matrix can effectively increase the tensile strength and deformation performance of sprayed FRP;earthquake damaged RC column can almost be rehabilitated to its designed ultimate load capacity before the earth-quake damage by strengthening with sprayed FRP,and both the ductility and the ability of energy dissipation can be effectively enhanced.This strengthening technique can fast strengthen the earthquake damaged RC column in seis-mic area and effectively hinder the collapse of whole structures exposed to the aftershock and other heavy damages.%通过12组72件喷射纤维/树脂复合材料(FRP)试样的拉伸强度

  11. The effect of Qingbi Tablet on the KLF6-FRP regulation system of rheumatoid arthritis process%清痹片对类风湿关节炎KLF6-FRP调控体系的干预作用

    Institute of Scientific and Technical Information of China (English)

    刘维; 吴沅皞; 刘晓亚; 张磊; 薛斌; 陈英俊

    2011-01-01

    Objective: The project intends to investigate the role of KLF6-FRP regulation system of rheumatoid arthritis process, then to illuminate the possible ati-arthritis mechanism of the Qingbi Tablet, as a scientific basis for the research and application of the antiarthritic traditional Chinese medicine. Methods: Focusing on the Qingbi tablet with the formulating principle of dispelling toxins and dredging collaterals, under the guidance of TCM theory, the experimental research used collagen-induced arthritis (CIA) as the experimental animal models with the incisiveness point of the KLF6-TGFpl-FRP network (Kruppel like transcription factor 6-Transforming growth factor β1-Follistatin related protein). Comparating with normal group, the CIA rats were divided randomly into 5 groups, treating with or without the Qingbi tablets of low, middle, high dosage (0.36gkg -1-d-1, lg-kg-1-d-1 or 1.8g-kg-1-d-1) or Methotrexate. One half of rats were sacrificed on the 35th or the 49th day. The wrist joints were collected for measuring the KLF6 and FRP by Western Blotting. And the ankle joints were collected for measuring the TGFβ1, TNFα, IL-1β and MMP-3 with the immunohistochemistry assay. Results: The expression levels of KLF6, FRP, TGFβ1, TNFα, IL-ip, MMP-3 of CIA in rats were higher significantly compared with the normal ones (P<0.01). With a dose dependent, the expressions of KLF6 in the rats treating with Qingbi tablets of lg-kg-1-d-1 or 1.8g-kg-1-d-1 were lower significantly compared with the model group but of FRP are higher (P<0.01). The expression levels of TGFpi, TNFα, IL-1β, MMP-3 in treated groups are significantly lower than the model group (P<0.01). The expression levels of TNFα, IL-1β, MMP-3 of Qingbi high dosage group were power than the MTX group (P<0.01). Conclusion: The Qingbi Tablet has the effects of intervening the expression the KLF6-FRP regulation system and related factors on the RA process effectively.%目的:探讨清痹片对KLF6-FRP调控体系

  12. 大型玻璃钢渔船帽型骨架剖面参数的力学分析%Mechanics Analysis for Section Parameters of Cap- shape Frames of Large FRP Fishing Vessels

    Institute of Scientific and Technical Information of China (English)

    蒋丰; 沈叔曾

    2000-01-01

    In this paper, the section parameters of the cap - shape frame of the large FRP fishing vessel is analyzed by elastic stability theory. Both two models of thin rectangle plates on compression and shear stability are established. The section parameter b/t1 and h/t are obtained in four cases that is the four combinations for two materials (1: 1FRP and 4:1 FRP) and two boundaries (all edges simply supported and all edges clamped). The ranges are from 18.0 to 26. 2 and from 28.7 to 44.2 respectively. The results provide theory basis for the optimal design of section parameters of the cap - shape frame and the revision of relevant standard.%本文对大型玻璃钢渔船帽型骨架剖面参数,进行了在不利受力情况下正交各向异性玻璃钢薄板稳定的力学分析,建立了骨架受力分析--受压区的矩形薄板压缩稳定和腹板的矩形薄板剪切稳定两种力学模型,解得这两种力学模型,在两种材料(1:1玻璃钢和4:1玻璃钢)与两种边界条件(四边简支和四边固支)组合的四种条件下,骨架剖面参数的b/t1和h/t的取值范围,它们依次为18.0~26.2和28.7~44.2。文中分析结果为帽型骨架剖面参数的优化设计和相关规范的修订提供了理论依据。

  13. 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

  14. BUILDING 341 Seismic Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Halle, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-06-15

    The Seismic Evaluation of Building 341 located at Lawrence Livermore National Laboratory in Livermore, California has been completed. The subject building consists of a main building, Increment 1, and two smaller additions; Increments 2 and 3.

  15. Tribal Green Building Toolkit

    Science.gov (United States)

    This Tribal Green Building Toolkit (Toolkit) is designed to help tribal officials, community members, planners, developers, and architects develop and adopt building codes to support green building practices. Anyone can use this toolkit!

  16. AH-64E Apache New Build (AH-64E New Build)

    Science.gov (United States)

    2015-12-01

    to simultaneously conduct (or quickly transition between) close combat, mobile strike, armed reconnaissance, manned-unmanned teaming, security and...Jul 2010 Jul 2010 Jan 2011 Sep 2010 Initial Operational Test and Evaluation ( IOT &E) Mar 2012 N/A N/A Mar 2012 Full Rate Production (FRP) Jul 2012 Jul

  17. Green building: sustainable building quality; Green Building: nachhaltige Gebaeudequalitaet

    Energy Technology Data Exchange (ETDEWEB)

    Staub, R.

    2010-07-01

    This article takes a look at the 'Portikon' office building near Zurich, Switzerland, that meets the 'Minergie-P' very low energy consumption requirements. The author is of the opinion that the project can be seen as a reference project for sustainable building technology. The structure of the seven-storey building with a central atrium is described and discussed. The 'Minergie-P' energy concept is discussed, as are the 1,100 square meters of photovoltaic panels on the roof of the building. Heating energy is provided by Zurich's waste incineration plant nearby. Electro-biological aspects in the building are taken care of by appropriate earthing and shielding of cables. The building's facility management system and the installations used are briefly discussed.

  18. 模拟混凝土碱性环境下FRP筋的耐久性%Durability of FRP Rebars in Alkaline Environment of Concrete

    Institute of Scientific and Technical Information of China (English)

    李趁趁; 于爱民; 王英来

    2013-01-01

    The durability of glass fiber reinforced polymer ( GFRP) rebar and basalt fiber reinforced polymer ( BFRP) rebar in alkali solution is studied. The test results show that the tensile strength and shear strength of GFRP bars decrease in alkali solution, and the changing degree is related to the treated time. GFRP bars continue to cure when being suffered from alkaline solution. The mechanical performance change of GFRP bars is from the role of alkali solution and the degree of post-curing. Alkali solution reduces the tensile strength, tensile modulus of elasticity and shear strength of BFRP bars, and the changing degree of the tensile strength and elasticity modulus increase with the increase of the treated time. Si-0 bonds in the glass fibers and basalt fibers rupture under the role of water molecules and OH , the hydrolysis of ester bonds in resin matrix in alkaline solution and the performance degradation of the bonding interface between fiber and resin are main reasons for the performance degradation of GFRP bars and BFRP bars. The alkali resistance of GFRP bars is better than that of BFRP bars. The possible mechanisms are revealed and the relevant recommendations to improve the alkali resistance of FRP bars are presented in the paper.%通过碱溶液模拟混凝土内部孔隙水的碱性环境,研究了碱性环境对玻璃纤维增强塑料筋(GFRP筋)和玄武岩纤维增强塑料筋(BFRP筋)的拉伸强度、拉伸弹性模量以及剪切强度、破坏形态等的影响.结果表明:碱溶液作用降低了GFRP筋的拉伸强度和剪切强度,降低程度与时间有关;GFRP筋在碱溶液中发生了后固化反应,GFRP筋的力学性能变化是碱溶液作用和后期固化程度综合影响的结果.碱溶液作用降低了BFRP筋的拉伸强度、拉伸弹性模量和剪切强度,随着碱溶液作用时间的增加,拉伸强度与拉伸弹性模量降低程度有增加的趋势.玻璃纤维和玄武岩纤维中的Si-O键在水分子和

  19. Danish building typologies

    DEFF Research Database (Denmark)

    Wittchen, Kim Bjarne; Kragh, Jesper

    The objective of TABULA is to develop a harmonised building typology for European countries. Each national building typology will consist of a set of residential model buildings with characteristic energy-related properties (element areas of the thermal building envelope, U-values, supply system...... efficiencies). The model buildings will each represent a specific construction period of the country in question and a specific building size. Furthermore the number of buildings, flats and the overall floor areas will be given, which are represented by the different building types of the national typologies....

  20. Danish building typologies and building stock analyses

    DEFF Research Database (Denmark)

    Wittchen, Kim Bjarne; Kragh, Jesper

    enough to meet the government’s plan to make Danish buildings free from use of fossil fuels by 2035. This will probably require around 50 % energy savings in the Danish building stock as a whole. However, the project has proven that dedicated engagement of locals can speed up market penetration...... energy savings in residential buildings. The intension with this analysis was to investigate the possible energy reduction in Denmark if the same approach had been taken for the entire Danish building stock. The report concludes that the ZeroHome initiative clearly results in energy savings, but far from...... for energy savings in the existing Building stock....

  1. 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。

  2. FINITE ELEMENT ANALYSIS OF PANEL CAPACITY IN FRP REINFORCED CONCRETE BRIDGE%对FRP筋混凝土桥梁面板承载力性能的非线性有限元分析

    Institute of Scientific and Technical Information of China (English)

    潘云锋; 郑愚; 于国友

    2011-01-01

    为了研究FRP筋混凝土梁面板的承载能力,采用了大型商用软件ABAQUS对Sherif EI-Gamal等的钢混桥梁模型进行了数值模拟.将非线性有限元计算结果同试验结果进行对比分析,非线性有限元的计算结果与试验结果吻合良好.基于数值模准确的分析结果,对结构体系中的压缩薄膜效应进行了分析,并开展了一系列的参数学习,包括混凝土强度、支撑梁刚度以及横隔梁.分析结果表明,压缩薄膜效应对FRP筋混凝土桥面板的承载能力有显著的影响.%In the investigation of ultimate strengths in FRP reinforced concrete bridge deck slabs, a commercial software named ABAQUS was used to establish the numerical model for steel-concrete composite bridge tests by Sheriff EI-Gamal et al. In the comparison of nonlinear finite element analysis and experimental tests, numerical re sults showed good accordance with those from experimental tests. According to the accurate validation, the analysis of compressive membrane action in this structural type were developed with a series of parametric study, including of concrete compressive strength, supporting beam stiffness and diaphragm beams. It was found that influence from compressive membrane action on loading capacities in FRP reinforced concrete bridge deck slabs was significant.

  3. FINITE ELEMENT ANALYSIS OF PANEL CAPACITY IN FRP REINFORCED CONCRETE BRIDGE%对FRP筋混凝土桥梁面板承载力性能的非线性有限元分析

    Institute of Scientific and Technical Information of China (English)

    潘云锋; 郑愚; 于国友

    2011-01-01

    为了研究FRP筋混凝土梁面板的承载能力,采用了大型商用软件ABAQUS对Sherif EI-Gamal等的钢混桥梁模型进行了数值模拟.将非线性有限元计算结果同试验结果进行对比分析,非线性有限元的计算结果与试验结果吻合良好.基于数值模准确的分析结果,对结构体系中的压缩薄膜效应进行了分析,并开展了一系列的参数学习,包括混凝土强度、支撑梁刚度以及横隔梁.分析结果表明,压缩薄膜效应对FRP筋混凝土桥面板的承载能力有显著的影响.%In the investigation of ultimate strengths in FRP reinforced concrete bridge deck slabs, a commercial software named ABAQUS was used to establish the numerical model for steel-concrete composite bridge tests by Sheriff EL-Gamal et al. In the comparison of nonlinear finite element analysis and experimental tests, numerical results showed good accordance with those from experimental tests. According to the accurate validation, the analysis of compressive membrane action in this structural type were developed with a series of parametri6c study, including of conccete compessive stength, supporting beam saiffness and diaphragm beams. It was found that influence from compressive membrane action on loading capacities in FRP reinforced concrete bridge deck slabs was significant.

  4. 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。

  5. 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

  6. 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 .

  7. Global building physics

    DEFF Research Database (Denmark)

    Rode, Carsten

    2013-01-01

    High ambitions are set for the building physics performance of buildings today. No single technology can achieve fulfilment of these ambitions alone. Integrated, multi-facetted solutions and optimization are necessary. A holistic, or ‘global’, technological perspective is needed, which includes all...... aspects of the building as defined in building engineering. We live in an international society and building solutions are developed across country borders. Building physics is a global theme. The International Association of Building Physics has global appeal. This brief article reports the keynote...... lecture and illustrates global relations to highlight some of the challenges that we see today....

  8. Global Building Physics

    DEFF Research Database (Denmark)

    Rode, Carsten

    2012-01-01

    aspects of the building as defined in building engineering. We live in an international society and building solutions are developed across country borders. Building physics is a global theme. The International Association of Building Physics has global appeal. The keynote lecture and this brief paper......High ambitions are set for the building physics performance of buildings today. No single technology can achieve fulfilment of these ambitions alone. Integrated, multi-facetted solutions and optimization are necessary. A holistic, or “global”, technological perspective is needed, which includes all...

  9. ICT Enhanced Buildings Potentials

    DEFF Research Database (Denmark)

    Christiansson, Per

    2007-01-01

    The paper describes and gives example on how Information and Communication, ICT, can and will enhance and support the building functional systems defined from client and end-user needs and requirements. The building systems may be derived from functional requirements on buildings such as usability...... and security on highest level with sub-systems definitions on lever levels. Building functional sub-systems may be defined for user comfort, indoor-climate, evacuation, space configuration, aesthetics, O&M etc. These building systems are supported by Information and Communication Technology, ICT, and building...... component systems that are accessed and integrated in the real world of building use in different contexts. The ICT systems may be physically or virtually embedded in the building. Already in 1982 AT&T established the 'intelligent buildings', IB, concept due to marketing reasons and the Informart building...

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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。

  15. 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.

  16. Retrofitting Listed Buildings

    DEFF Research Database (Denmark)

    Rasmussen, Torben Valdbjørn

    2011-01-01

    The paper presents a case study where the energy demand for a listed building constructed in 1900 is reduced. Many older buildings are listed and have restrictions that include the entire building or that include only its exterior. For the building presented, only its exterior facade is listed...... of the local urban environment and therefore listed. The reduced energy demand, related to individual measures, is estimated and building physics requirements are addressed together with the economic options for evaluating the profitability....

  17. 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.

  18. 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.

  19. Sustainable Buildings in Interaction

    DEFF Research Database (Denmark)

    Elle, Morten

    2007-01-01

    The first attempts to build sustainable buildings in Denmark were typically located on the countryside. The basic idea was to create buildings that were independent of the technical infrastructure. District heating has, however, been the dominating solution to heating in buildings in Denmark......, and the focus on sustainable building have gradually turned from special houses on the countryside to normally looking houses in the urban fabric, integrated in the technical infrastructure. Some new built urban areas in Denmark will, however, not have to be supplied with district heating – these developments...... are going to consist of passive houses. The first sustainable buildings were built by their users, and the user – building interaction still play a decisive role for the performance of the present sustainable buildings. The users have to understand how the building functions. Urban design is essential...

  20. Importance of Building Code

    Directory of Open Access Journals (Sweden)

    Reshmi Banerjee

    2015-06-01

    Full Text Available A building code, or building control, is a set of rules that specify the minimum standards for constructed objects such as buildings and non building structures. The main purpose of building codes are to protect public health, safety and general welfare as they relate to the construction and occupancy of buildings and structures. The building code becomes law of a particular jurisdiction when formally enacted by the appropriate governmental or private authority. Building codes are generally intended to be applied by architects, engineers, constructors and regulators but are also used for various purposes by safety inspectors, environmental scientists, real estate developers, subcontractors, manufacturers of building products and materials, insurance companies, facility managers, tenants and others.

  1. Applied building physics

    CERN Document Server

    Hens, Hugo S L C

    2012-01-01

    The energy crises of the 1970s, persisting moisture problems, complaints about sick buildings, thermal, visual and olfactory discomfort, and the move towards more sustainability in building construction have pushed Building Physics to the forefront of building innovation. The societal pressure to diminish energy consumption in buildings without impairing usability acted as a trigger to activate the whole notion of performance based design and construction. As with all engineering sciences, Building Physics is oriented towards application, which is why, after a first book on fundamentals this s

  2. 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。

  3. 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。

  4. 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).

  5. 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.

  6. Building Design & Construction - Sustainability

    Energy Technology Data Exchange (ETDEWEB)

    None

    2003-11-01

    Offers a brief history of green building; presents the results of a specially commissioned survey; and analyzes the chief trends, issues, and published research, based on interviews with dozens of experts and participants in green building.

  7. Better Buildings Challenge Overview

    Energy Technology Data Exchange (ETDEWEB)

    None

    2011-06-01

    The Better Buildings Challenge is a national leadership initiative calling on corporate chief executive officers, university presidents, and state and local leaders to make a significant commitment to building energy efficiency.

  8. Environmental indicators for buildings

    DEFF Research Database (Denmark)

    Dammann, Sven

    Environmental Indicators for Buildings are studied using two different perspectives: with a technological, environmental scientific departing point and with a social scientific departing point. Different relevant groups in the building sector are identified and analysed, using the Social...

  9. Integrated Building Health Management

    Data.gov (United States)

    National Aeronautics and Space Administration — Abstract: Building health management is an important part in running an efficient and cost-effective building. Many problems in a building’s system can go undetected...

  10. Building Services Systems

    DEFF Research Database (Denmark)

    Zinzi, Michele; Romeo, Carlo; Thomsen, Kirsten Engelund

    2015-01-01

    This guideline on Building Services Systems is one of four guidelines produced by the School of the Future project. The other three guidelines cover: Building Construction Elements, Improved Indoor Environmental Quality and Concepts for Zero Emission Schools. This guideline consists...

  11. Robotic buildings(s)

    NARCIS (Netherlands)

    Bier, H.H.

    2014-01-01

    Technological and conceptual advances in fields such as artificial intelligence, robotics, and material science have enabled robotic building to be in the last decade prototypically implemented. In this context, robotic building implies both physically built robotic environments and robotically supp

  12. State Capitol Buildings

    Data.gov (United States)

    Department of Homeland Security — This shapefile will display the locations of the fifty state capitol buildings as well as the territorial capitol buildings for the US Virgin Islands, Guam, Northern...

  13. Comfort control in buildings

    CERN Document Server

    Castilla, Maria del Mar; Rodriguez, Francisco de Asis

    2014-01-01

    This book describes both concepts and development of advanced comfort control systems in buildings, with significant energy saving, and attention to thermal, visual and indoor air quality. The concepts are proven through real tests in a bioclimatic building.

  14. Requirements for existing buildings

    DEFF Research Database (Denmark)

    Thomsen, Kirsten Engelund; Wittchen, Kim Bjarne

    2012-01-01

    This report collects energy performance requirements for existing buildings in European member states by June 2012.......This report collects energy performance requirements for existing buildings in European member states by June 2012....

  15. Buildings interoperability landscape - Draft

    Energy Technology Data Exchange (ETDEWEB)

    Hardin, Dave B. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Stephan, Eric G. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Wang, Weimin [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Corbin, Charles D. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Widergren, Steven E. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)

    2015-02-01

    Buildings are an integral part of our nation’s energy economy. The advancement in information and communications technology (ICT) has revolutionized energy management in industrial facilities and large commercial buildings. As ICT costs decrease and capabilities increase, buildings automation and energy management features are transforming the small-medium commercial and residential buildings sectors. A vision of a connected world in which equipment and systems within buildings coordinate with each other to efficiently meet their owners’ and occupants’ needs, and where buildings regularly transact business with other buildings and service providers (such as gas and electric service providers) is emerging. However, while the technology to support this collaboration has been demonstrated at various degrees of maturity, the integration frameworks and ecosystems of products that support the ability to easily install, maintain, and evolve building systems and their equipment components are struggling to nurture the fledging business propositions of their proponents.

  16. Building a case for building performance

    OpenAIRE

    Lehrer, David

    2001-01-01

    You have seen the facts before. Americans make up less than 5% of the world’s population, yet consume 25% of the earth’s resources and create 25% of the world’s greenhouse gases. We are also told that the construction and operation of buildings are major contributors to this problem, and that as building industry professionals we have a major responsibility to improve the performance of the buildings and environments that we create. Although a growing number of states and municipalit...

  17. Green Building Research Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Sailor, David Jean [Portland State Univ., Portland, OR (United States)

    2013-12-29

    This project provided support to the Green Building Research Laboratory at Portland State University (PSU) so it could work with researchers and industry to solve technical problems for the benefit of the green building industry. It also helped to facilitate the development of PSU’s undergraduate and graduate-level training in building science across the curriculum.

  18. Future Green Buildings

    DEFF Research Database (Denmark)

    Mathiesen, Brian Vad; Drysdale, David; Lund, Henrik

    Efficient buildings are essential for an affordable Danish energy supply in 2050. The purpose of this report is to describe the contribution and role of the building sector in a 100% renewable energy future, as well as the transitions that are necessary in the building sector to support this chan...

  19. Building the ISS

    Institute of Scientific and Technical Information of China (English)

    石继忠; 李秀霞

    2007-01-01

    Have you seen people building houses?To build a house,you need workers.They use their hands,tools and machines to put everything together. Building the ISS is almost the same.The difference is that the workers are astronauts.They

  20. Building with Straw.

    Science.gov (United States)

    Di Santo, Gilbert

    2000-01-01

    Discusses the early use of straw in Africa and Europe as a building material. Provides background information and a basic framework for the straw bale project, and recommends supervision for young students. Lists objectives for building a straw bale bench and provides the building instructions which consist of three sessions. Includes four…