• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제5권6호
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• pp.674-685
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• 1999

MIDAS-II는 한국전자통신연구원에서 개발한 바다 DBMS의 저장 시스템이다. MIDAS-II 볼륨은 데이터의 논리적 저장 단위인 파일을 저장하는 영역을 가리킨다. 본 논문에서는, MIDAS-II가 대용량 멀티미디어 데이터 서버의 저장 시스템으로 기능하도록 광 디스크 쥬크박스 또는 테이프 라이브러리와 같이 복수 개의 저장 매체 (platter , 예를 들어 디스크 또는 카트리지 테이프)로 구성된 Tera 바이트 급의 3창 저장 장치를 장착할 경우 이를 위한 볼륨 구조의 설계 및 구현에 대해 기술한다. 본 논문에서 제안하는 볼륨 구조는 3차 저장 장치 접근 시 성능 제고를 위하여 디스크 캐쉬 영역을 두고 있으며, 3차 저장 장치의 저장 매체별 관리 기능을 제공한다. Abstract MIDAS-II is the storage systemfor BADA DBMS developed at ETRI. A volume of MIDAS-II is the area where the files, the logical unit for storing data, are stored. This paaper describes the design and implementation of a new MIDAS-II volume structure for the tertiary storage device such as an optical disk juke box or a tape library equipped with multiple platters(disks or cartridge tapes, for example ). Incorporating thetertirary storage device of the order of tera bytes into MIDAS-II enables it to function as a storage system for a massive amount fo multimedia eata server. The volume structure for the tertiary storage device proposed in this paper features disk caching for performing improvement and direct control of theindividual platter.

• 설비공학논문집
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• 제18권4호
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• pp.287-296
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• 2006

In this paper, optimal control strategy of the air-conditioning system with slab thermal storage was investigated based on the optimal control theory. An optimal heat output to the plenum chamber and the air-conditioned room was determined based on two kinds of criterion functions. The first one requires small deviation in room air temperature from a set-point value and low energy consumption. It is shown that the optimized control is to store heat through the whole storage time and to increase storage rate gradually with time. As the second case, a criterion that both a deviation of operative temperature from a set-point temperature and the energy consumption should be minimized was adopted. The room air temperature was a little high and the cooling load during storage time was reduced, compared with the results when a criterion function considering only the room air temperature is used.

• 제어로봇시스템학회논문지
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• 제7권10호
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• pp.867-873
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• 2001

The purpose of this study is to find analytic solution of determining the optimal capacity (lot-size) of multiproduct acyclic multistage production and inventory system to meet the finished product demand under the constraint of finite intermediate storage. Intermediate storage is a practical way to mitigate the material flow imbalance through the line of supply and demand chain. However, the cost of constructing and operating storage facilities is becoming substantial because of increasing land value, environmental and safety concern. Therefore, reasonable decision-making about the capacity of processes and storage units is an important subject for industries. The industrial solution for this subject is to use the classical economic lot sizing method, EOQ/EPQ(Economic Order Quantity/Economic Production Quantity) model, incorporated with practical experience. But EOQ/EPQ model is not suitable for the chemical plant design with highly interlinked processes and storage units because it is developed based on single product and single stage. This study overcomes the limitation of the classical lot sizing method. The superstructure of the plant consists of the network of serially and/or parallelly interlinked non-continuous processes and storage units. The processes transform a set of feedstock materials into another set of products with constant conversion factors. A novel production and inventory analysis method, PSW(Periodic Square Wave) model, is applied to describe the detail material flows among equipments. The objective function of this study is minimizing the total cost composed of setup and inventory holding cost. The advantage of PSW model comes from the fact that the model provides a set of simple analytic solutions in spite of realistic description of the material flows between processes and storage units. the resulting simple analytic solution can greatly enhance the proper and quick investment decision for the preliminary plant design problem confronted with economic situation.

• 설비공학논문집
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• 제28권1호
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• pp.7-14
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• 2016

This study explores the feasibility of a cold storage system to provide thermal comfort for idle stop and go (ISG) vehicles. ISG function is the most valuable and environmental friendly technology in the current automobile industry. However, when an ISG vehicle stops, meaning when the engine standstill, the air-conditioning system does not work, because the compressor also stops. Therefore, passenger thermal comfort is not maintained, as cold air is not provided in the cabin. Consequently, many automakers have studied electric air-conditioning systems based on electrically-driven compressors or cold storage systems using phase-change materials. The experiments herein were conducted for the feasibility testing of different types of cold storage heat-exchangers, cold storage mediums, and thermo-expansion valves with current air-conditioners. The auxiliary cold storage system, filled with phase-change materials, was located behind the evaporator and almost stacked on top of it. In the experimental results, the air discharge temperature rate of increase was better than the conventional air-conditioning system when the compressor stopped and thermal comfort was maintained with $1.9{\sim}4.3^{\circ}C$ decreases within 60 seconds. The #1 cold storage heat-exchanger (CSH), #2 thermo-expansion valve (TXV) and #2 phase change material (PCM) were chosen because of the best temperature rise delay. It was concluded that a cold storage system is an effective solution for ISG vehicles to maintain thermal comfort during short engine stops.

• 디지털포렌식연구
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• 제12권3호
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• pp.27-38
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• 2018

최근 디지털 데이터의 양이 급격하게 증가함에 따라 대용량 저장 공간의 필요해지고 있다. RAID는 이러한 대용량 저장 공간을 관리할 수 있는 시스템이다. Windows에서 제공하는 저장소 공간은 소프트웨어 RAID의 일종이다. 저장소 공간은 Windows 8, Windows Server 2012 버전부터 지원되었으며 해당 기능에 대한 분석이 기존에 이루어져 있지 않다. 저장소 공간을 이용한 시스템을 분석하기 위해서는 저장소 공간 기능에 대한 분석과 가상 디스크 재구성 방법에 대한 연구가 이루어져야 한다. 본 논문에서는 기존 RAID의 레이아웃에 대해 간단히 설명하고 소프트웨어 RAID인 저장소 공간의 구성 방식과 메타데이터를 설명하고 구성 방식별로 가상 디스크의 재구성 방법을 제시하고 실험을 통해 이를 검증하였다.

• Journal of Plant Biology
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• 제36권4호
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• pp.327-335
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• 1993

The active sites, intracellular transport, function of cellulase in association with the disintegration of the storage materials of the endosperm cells during seed maturation and after-ripening of Panax ginseng C.A. Meyer seeds were studied by electron microscopy. Cytochemical activities of the cellulase occurred in protein bodies and vesicles of endosperm cells in seed with red seed coat. In after-ripening seed, the activities were strongly found in the cell wall of endosperm near the umbiliform layer and on neighbouring vesicles, so it is assumed that these cells begin to be decomposed. Cellulase activities were initiated before the decomposition of storage materials. But, no activity was observed in the umbiliform layer, so it is suggested that cellulase lose its activity after the completion of lysis process.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2005년도 학술발표회 논문집
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• pp.731-736
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• 2005

현재 국내 주요 하천의 홍수예경보시스템 운영과 다목적댐의 홍수조절관리를 위하여 수문학적 모형의 하나인 저류함수모형(Storage Function Model)을 사용하고 있다. 저류함수모형은 산지가 많은 유역에 적합하도록 개발된 모형으로, 계산절차가 간편하고 홍수유출의 비선형성을 고려할 수 있는 방법이므로 선형모형보다 합리적이라고 알려져 있다. 그러나 저류함수모형을 실제 홍수유출현상에 적용하는데 있어 매개변수를 결정하는 것이 매우 어렵다. 현재 매개변수들을 결정할 수 있는 객관적이고 합리적인 방법이 제시되어 있지 않기 때문에 모형의 매개변수를 결정할 때 경험식을 이용하거나 수문기술자의 판단에 의한 보정에 의존하고 있다. 따라서, 본 논문에서는 홍수통제소에서 사용하고 있는 저류함수 모형의 대표(평균) 매개변수와 경험식, 시행착오법(trial & error method) 및 최적화기법(optimization technique) 중에 Rosenbrock 방법을 이용하여 매개변수를 산정하고 이들을 비교 분석하고자 한다.

• 대한전기학회논문지
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• 제34권8호
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• pp.308-316
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• 1985

This paper proposes an analytic tool for long-term generation expansion planning based on the maximum principle. Many research works have been performed in the field of generation expansion planning. But few works can be found with the maxinmum principle. A recently published one worked by professor Young Moon Park et al. shows remarkable improvements in modeling and computation. But this modeling allows only thermal units. This paper has extended Professor Park's model so that the optimal pumped-storage operation is taken into account. So the ability for practical application is enhanced. In addition, the analytic supply-shortage cost function is included. The maximum principle is solved by gradient search due to its simplicity. Every iteration is treated as if mathematical programming such that all controls from the initial to the terminal time are manipulated within the same plane. Proposed methodology is tested in a real scale power system and the simulation results are compared with other available package. Capability of proposed method is fully demonstrated. It is expected that the proposed method can be served as a powerful analytic tool for long-term generation expansion planning.

• 대한전기학회논문지
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• 제32권5호
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• pp.176-182
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• 1983

This paper derives a newly neveloped analytic optimal condition to minimize the operating cost of a generation system in the aspect of Power System Planning, When the system includes pumped-storage units. The analytic optimal condition is derived by defferentiating the analytic cost function, Which were obtained by assuming the load and generating as Gaussian random variables, with respect to the variations of pumping energy. The condition is resulted in very simple form and various optimization techniques can be used. The simulation results of a case study were compared with the results of the conventional methods to prove the usefulness of the algorithm.

• 소음진동
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• 제9권5호
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• pp.891-898
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• 1999

The purpose of Superconducting Magnetic Bearing Flywheel Energy Storage System (SMB-FESS) is to store unused nighttime electricity until it is needed during daytime. An analytical model of the SMB-FESS is necessary to identify the system behavior. At first, we have to model the superconducting magnetic bearing. Modeling the SMB is same as estimating the bearing parameter. The theoretical modal parameter is calculated through the equation of motion and the experimental modal parameter is estimated through the impact testing (modal testing). The bearing parameter is searched by using the non-linear least square method until the theoretical result corresponds to the experimental result. The suggested modeling method is verified by comparing experimental and analytical frequency response function.