• 제목/요약/키워드: Time of storage

검색결과 5,193건 처리시간 0.041초

풍력발전기 출력변동성에 대비한 가변속 양수발전기의 주파수 제어효과 (Effect of Adjustable Speed Pumped Storage Power Generator on the Frequency Control Against the Intermittence of Wind Turbine Output)

  • 박민수;전영환
    • 전기학회논문지
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    • 제63권3호
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    • pp.338-342
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    • 2014
  • Energy storage is a key issue when integrating large amounts of intermittent and non-dispatchable renewable energy sources into electric power systems. To maintain the instantaneous power balance and to compensate for the influence of power fluctuations from renewable sources, flexible capability for power control is needed. Adjustable Speed Pumped Storage Power Generator is pumped storage unit that is adjustable for pump output adjustments as well as the highest efficiency operations because it has fast response time. In this paper we address the adjustable speed pumped storage power generator for frequency control against the intermittence of wind turbine output and calculate the appropriate capacity of adjustable speed pumped storage power generator.

면진 유체 저장 탱크의 지진취약도 분석 (Seismic Fragility Analysis of Base Isolated Liquid Storage Tank)

  • 안성문;최인길;전영선
    • 한국지진공학회:학술대회논문집
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    • 한국지진공학회 2005년도 학술발표회 논문집
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    • pp.453-460
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    • 2005
  • In this study, the seismic fragility analysis of a base isolated condensate storage tank installed in the nuclear power plant. The condensate storage tank is safety related structure in a nuclear power plant. The failure of this tank affect significantly to the core damage frequency of the nuclear power plants. The seismic analysis of the liquid storage tank was performed by the simple calculation method and the dynamic time storage analysis method. The convective and impulsive fluid mass is modeled as added masses proposed by several researchers. To evaluate the effectiveness of the isolation system, the comparison of HCLPF and core damage frequencies in non-isolated and isolated cases are carried out. It can be found from the results that the seismic isolation system increases the seismic capacity of a condensate storage tank and decreases the core damage frequency significantly.

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A Regular Expression Matching Algorithm Based on High-Efficient Finite Automaton

  • Wang, Jianhua;Cheng, Lianglun;Liu, Jun
    • Journal of Computing Science and Engineering
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    • 제8권2호
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    • pp.78-86
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    • 2014
  • Aiming to solve the problems of high memory access and big storage space and long matching time in the regular expression matching of extended finite automaton (XFA), a new regular expression matching algorithm based on high-efficient finite automaton is presented in this paper. The basic idea of the new algorithm is that some extra judging instruments are added at the starting state in order to reduce any unnecessary transition paths as well as to eliminate any unnecessary state transitions. Consequently, the problems of high memory access consumption and big storage space and long matching time during the regular expression matching process of XFA can be efficiently improved. The simulation results convey that our proposed scheme can lower approximately 40% memory access, save about 45% storage space consumption, and reduce about 12% matching time during the same regular expression matching process compared with XFA, but without degrading the matching quality.

그래프 이력 데이터 접근을 위한 효과적인 저장 관리 기법 (Efficient Storage Management Scheme for Graph Historical Retrieval)

  • 김기훈;김이나;최도진;김민수;복경수;유재수
    • 한국콘텐츠학회논문지
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    • 제18권2호
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    • pp.438-449
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    • 2018
  • 최근 소셜 네트워크, 인용 네트워크 등 여러 분야에서 다양한 그래프 데이터가 활용되고 있다. 시간에 따라 그래프가 동적으로 변화함에 따라 변경 내용 추적 및 특정 시점 그래프 검색을 위해 그래프 이력 데이터를 관리하는 것이 필요하다. 대부분의 이력 데이터는 시간에 따라 부분적인 변화가 발생하기 때문에 시간 단위로 데이터를 저장할 경우 변경되지 않은 데이터가 중복 저장된다. 본 논문에서는 시간별 그래프의 중복 저장을 최소화하기 위한 그래프 이력 저장 관리 기법을 제안한다. 제안하는 기법은 그래프의 변화를 계속적으로 탐지하여 과거 그래프와 중복되는 서브 그래프를 하나의 중복 스냅샷에 저장한다. 중복 스냅샷에는 다수의 델타 스냅샷이 연결되어 각 시간에 따른 변화 데이터를 유지한다. 중복 스냅샷에 저장된 중복 데이터를 공통으로 관리하여 공간의 효율을 향상시킨다. 또한, 해당 시점의 그래프를 탐색하기 위해서 중복 스냅샷과 델타 스냅샷을 연결하였다. 제안하는 기법의 우수성을 보이기 위해 다양한 성능평가를 수행한다.

Effects of Storage Environmental Conditions on Weight Loss, Whiteness Change, and Microbial Activity of Mushrooms (Agaricus bisporus)

  • Pai, Tongkun
    • Journal of Applied Biological Chemistry
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    • 제43권3호
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    • pp.161-164
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    • 2000
  • The effects of storage temperature and high relative humidity (RH) on the weight loss, color change, and microbial activity of a mushroom ('Sylvan' hybrid white) were investigated. The experiment was performed at three temperature (5, 10 and $15^{\circ}C$) and four different relative humidity levels (91, 94, 97 and 99%). The weight loss of the tested samples had a highly correlated linear relationship with storage time at each RH level during storage. Both the storage temperature and RH levels in the experiment had signigicant effects (p<0.05) on the weight-loss rate of the tested samples. The loss whiteness of mushrooms was not significantly affected (p>0.05) by RH ranges at the same temperature. No visible damage was caused by either bacteria or fungi in all samples during storage.

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실시간 영상을 이용한 자동창고시스템의 원격 조작 및 감시 (Remote Control and Monitoring of Automatic Storage and Retrieval Systems using Real-Time Images)

  • 김석호;한영근;박강;강경식
    • 대한안전경영과학회지
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    • 제4권3호
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    • pp.67-78
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    • 2002
  • Automated manufacturing systems are applied to shop floors as tools for increase of productivity and quality and the decrease of manufacturing lead times and industry accidents. One of the most important issue of the present day is the application of Internet. The development of Internet technologies makes manufacturing enterprises break spacial barriers between users and shop floors, and collect various field data in remote sites. In this research, an Internet-based remote control system for a small-sized automated storage and retrieval system is developed for the purpose of real-time monitoring and control of automatic production equipment. The developed system has a client-server architecture and sends real-time images of the automated storage and retrieval system to clients by an CCD camera connected to a server.

조리, 재가열 방법 및 저장 조건이 너비아니 품질 특성에 미치는 영향 (Effect of Cooking, Reheating Methods and Storage Conditions on the Quality Characteristics of ′Nuhbiani′)

  • 김정원;김희섭
    • 한국식품조리과학회지
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    • 제11권5호
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    • pp.494-502
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    • 1995
  • The study was conducted to evaluate the characteristics of Nuhbiani qualities with the different cooking, reheating methods and storage conditions. Cooking and reheating methods were used with pan, microwave and their combinations. Precooked samples were stored for 0, 1, 4, 7, 15 days in the refrigerator and for 15, 30 days in the freezer. TBA value, shear value by rheometer and sensory attributes in rancidity, hardness, juiciness and overall acceptability were measured. There was no significant difference between cooking, reheating methods in TBA values. Lower values in TBA were noted in the Nuhbiani of frozen storage as compared with that of refrigerated storage. There is a tendency that TBA values were increased as the storage time extended during the refrigeration. Shear values were more increased by microwave cooking and microwave reheating than other methods showing harder texture. Results from sensory evaluation of rancidity, hardness, juiciness and overall acceptability show that there were no significant differences between storage methods, among storage periods and cooking, reheating methods.

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Performance Improvement Using Iterative Two-Dimensional Soft Output Viterbi Algorithm Associated with Noise Filter for Holographic Data Storage Systems

  • 누엔딘지;이재진
    • 한국통신학회논문지
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    • 제39A권3호
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    • pp.121-126
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    • 2014
  • Demand of the data storage becomes more and more growing. This requests the next generation of storage devices to have the dominated storage capability associated with superfast read/write rate. Holographic data storage (HDS) is investigated for a long time and is considered to be a candidate for the future storage system. However, it has two-dimensional intersymbol interference that conventional one-dimensional detection solutions have not yet handled strictly because of the complexity level of system as well as the cost. We propose a new scheme that combines iterative soft output Viterbi algorithm with noise filter for improving the bit error rate performance of HDS.

다품종용 회분식 공정에서의 중간 저장 탱크 공유를 위한 최적 생산계획 ; 회분식 조업의 자동화 모델 (Optimal Scheduling of Multi-product Batch Process for Common Intermediate Storage Policy; A Model for Batch Process Automation)

  • 정재학;이인범;양대륙;장근수
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1992년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 19-21 Oct. 1992
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    • pp.303-308
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    • 1992
  • In this study, we propose a shared storage system which is more efficient policy than MIS(Mixed Intermediate Storage) policy for relatively rare storage system and can be called CIS(Common Intermediate Storage) policy. Using this strategy, we develop a new completion time algorithm and apply it to two kinds of optimal or near optimal scheduling method; combinatorial search and simulated annealing method. We also extend this strategy to other storage policy, for example MIS policy, with PLC(Programmable Logic Controller) logic and on/off action of electronic valves. It thus can be accepted as a basic form of FMS(Flexible Manufacturing System) for operating various storage policies. Finally we suggest the interlocking block to compansate for the shortcoming of CIS policy, i.e, complication of operation and safety, resulting in a basic batch process automation mode.

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잠열 축열 - 바이오 세라믹 온돌의 난방 특성 - 이론적 분석을 중심으로 - (Floor Heating Characteristics of Latent Heat Storage - Bioceramic Ondol - Focused on Theoretical Analysis -)

  • 송현갑;유영선
    • 한국에너지공학회:학술대회논문집
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    • 한국에너지공학회 1995년도 춘계학술발표회 초록집
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    • pp.213-222
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    • 1995
  • Korean traditional Ondol with the sensible heat storage medium has been for a long time used as residential heating system, in these days the concrete Ondol without the heat storage medium was realized as the heating system in the private houses and the apartments. This floor heating system is good for our health. But the concrete Ondol is not desirable for the energy saving and for the maintenance of comfortable room temperature because the heat storage medium is not employed in the concrete Ondol. And as the hot water circulating pipes ate buried under the the concrete floor, the concrete Ondol system has some kind of problems to be improved. Therefore the new type of Ondol system was developed in this study. And the new Ondol was consisted of latent heat storage material as heat storage medium with a great heat capacity and bioceramics as medium to maintain comfortable room temperature. In this study, the heat transfer characteristics of latent heat storage-bioceramic Ondol was analyzed theoretically.

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