• 대한산업공학회지
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• 제19권4호
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• pp.97-104
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• 1993

This paper deals with the design problem of a man-on-board(MOB) storage and retrieval warehousing system which is suitable for storing items of small size and light weight. It is assumed that the operator carries out a sequence of retrieving(or storing) operations traveling on a specially designed truck. Considering the operating characteristics of the man-on-board system, an optimal design model is developed in which the investment and maintenance costs of the system are minimized over a time horizon satisfying a set of constructional restrictions. The model is formulated as a nonlinear integer program and a search algorithm is proposed to find an optimum solution.

• 대한전기학회논문지
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• 제39권7호
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• pp.653-667
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• 1990

Superconductor is consolidated, for required current capacity, with proper numbers of basic strands which are multifilamentary composites. Althouth superconductors are perfectly loss-free under DC conditions of current and field, AC losses occur under time-varying condition of the current and field. The AC losses are a controllable inherent characteristics of supercondectors. The AC losses dependent on the changing rate of current and field can be reduced by reducing the filament diameter. On the other hand, finer filament results in manufacturing cost increase. Therefore, in this paper optimization technique of superconductor for SMES is proposed from the viewpoint of AC loss reduction and manufacturing cost increase. The case study shows that the technique can be effectively used for the design of superconductor for SMES, appreciating the influence of various parameters related to superconductor itself and operating condition of SMES. As a result of the case study, it is confirmed that the technique is more effective for the design of superconductor for SMES for electric power power system stabilization rather then SMES for energy storage.

• 대한설비공학회지:설비저널
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• 제14권3호
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• pp.175-186
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• 1985

This paper presents a method for estimating the useful output of solar space heating system and estimates their performance with variance of collector size, storage volume, collector tilt and other factors . The analysis is performed by the computer simulation and by 'running' conceptual systems against solar intensities and ambient temperature for a model year stored in a computer. System performance is analyzed on monthly and yearly basis respectively and at the same time, the economics of various systems are evaluated . And also, this paper shows how an optimized design can be selected for any locality for which solar data, economic parameters and system performance are provided. It is shown that storage volume of 75 liter per $m^2$ of solar collector lead to the best design.

• 한국자동차공학회논문집
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• 제16권5호
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• pp.179-189
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• 2008

The performance of Lean NOx Trap (LNT) based on the catalysts of Pt/K/Ba/$\gamma-Al_2O_3$ with proprietary washcoat formulation is studied using a bench flow reactor system. To investigate the effect of temperature and gas hourly space velocity (GHSV) on the nitrogen oxides (NOx) trapping capacity as well as NOx breakthrough time and final ratio of $NO_2$ to NO of LNT, series of adsorption isotherms are carried out with simulated exhaust gases of the lean burn engines. Since typical operation of LNT requires periodic regeneration with a short rich excursion, where the stored or trapped NOx is released and subsequently reduced to $N_2$, the effect of the duration of lean and rich phase and type of reductants on the NOx conversion is investigated. NOx storage capacity and breakthrough time obtained from adsorption isotherms shows a volcano-type dependence on the temperature with a maximum NOx storage capacity occurring $350^{\circ}C$ and with a maximum breakthrough time occurring $400^{\circ}C$ at all GHSVs investigated in this study. Also, maximum ratio of $NO_2$ to NO is obtained at $400^{\circ}C$ with a GHSV of $75,000\;hr^{-1}$ Lean/rich cycle of 100 s lean and 5 s rich used with a concentration of 1.33% of $H_2$ and 4% of CO in the rich phase is found to be optimum at operating temperature of $350^{\circ}C$ and a GHSV of $50,000\;hr^{-1}$.

• 전기학회논문지
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• 제67권1호
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• pp.38-45
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• 2018

In September 2016, the government decided to apply a REC 5.0 weighting to solar-battery ESS to increase the supply of renewable energy. In this paper, we calculated the optimal capacity of battery ESS which maximizes the revenue when solar is linked with battery ESS. In the case study, the optimal capacity was calculated by applying the conservative REC price, and we studied sensitivity analysis about battery price and real-time REC price.

• 생명과학회지
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• 제9권1호
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• pp.44-49
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• 1999

품질이 양호한 참가자미 조미 반건조제품을 제조하기 위한 기초자료를 얻기 위하여, 참가자미를 조미 반건조한 후 나일론＋폴리에틸렌+선형 저밀도폴리에틸렌 (0.0l5/0.045/0.040 mm)의 적층필름으로 진공포장하여 각각 빙결점 동결저장 (-3$\pm$$0.5^{\circ}C$) 및 냉장 (3$\pm$$0.5^{\circ}C$)하면서 저장중의 품질변화를 검토하였다. 참가자미 반건조제품의 제조를 위한 가장 적합한 냉풍 건조온도 및 시간은 상대습도 50$\pm$5$\%$ 및 풍속 2 m/sec의 조건하에서 각각$20^{\circ}C$ 및 4시간이었으며, 진공포장한 제품의 저장수명은 빙결점 동결저장 (-3$\pm$$0.5^{\circ}C$) 시 35일이었고 냉장 (3 $\pm$$0.5^{\circ}C$) 시 16일이었다.

• 한국포장학회지
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• 제26권2호
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• pp.113-118
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• 2020

Due to the rapid increase in cyber shopping mall of agricultural products, the parcel delivery service industry also increased, making it necessary to design an optimum packaging for agricultural products. And Due to the recent increase in strawberry consumption, there is also a need for a packaging system for parcel delivery service. In order to establish the criteria for optimum cushioning packaging design of strawberries, the bioyield strength of strawberries by storage time was measured through the ASABE test standards, and the peak acceleration in the resonance frequency and resonance frequency bands of strawberries was measured through the vibration test regulated in the ASTM test specifications. Tray cup pad and corrugated fiberboard box of delivery strawberries were designed using FEM theoretical analysis of contact stress and resonant frequency. In addition, an optimum packaging system was developed with a cushioning and vibration design considering the impact characteristics when distributing agricultural products. Through the performance evaluation and on-site evaluation of the optimum packaging system of strawberries for parcel delivery service, the random PSD test results of the delivery showed a 74% reduction in the acceleration level, and the actual distribution test of the delivery showed that the damage rate of strawberries was not more than 6.7%, indicating that it was possible to use the optimum packaging of strawberries for delivery.

• 한국식품과학회지
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• 제24권2호
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• pp.137-141
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• 1992

고추 oleoresin의 적정 추출조건을 설정하기 위하여 추출에 영향을 미치는 몇 가지 인자들을 대상으로 oleoresin의 수율, capsanthin 및 capsaicin 함량의 변화를 조사하였다. Ethyl alcohol 용매로 추출한 oleoresin은 수율 및 capsanthin 함량이 높고, Ethylene dichloride 용매의 경우는 capsaicin 함량이 높게 나타났다. 혼합용매의 경우는 단일용매의 경우보다 수율은 증가하나 capsanthin 및 capsaicin 함량은 거의 변화가 없었다. 추출에 사용한 3가지 품종 중에서 진솔에서 추출한 oleoresin의 품질이 가장 우수하였다. 적정 추출온도 및 추출시간은 $20^{\circ}C$ 및 $3{\sim}5$시간이었다. 장기 저장한 고추일수록 고추분말의 입도가 클수록 추출되는 oleoresin의 품질은 저하되고, 함량도 적었다 고추의 과피에는 capsanthin이 씨에는 capsaicin이 가장 많았다. 고추분말과 추출용매의 적정혼합비는 $1\;:\;3{\sim}1\;:\;4(w/v)$였다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 춘계학술대회
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• pp.511-514
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• 2007

Gas hydrate has a unique property that can store a large volume of gas in water as a solid form. Even though investigations for natural gas storage technology have been carried out for several decades, there are still a lot of unsolved problems due to complex formation process, low formation speed, high energy consumption and so on. So, lots of experiments were conducted to overcome these weaknesses and to develop artificial NGH formation technology applicable to industrial-scale storage and commercial transport. In this study, some series of experiments were performed to analyze both stirred and unstirred system especially about the influences of several gas hydrate formation factors such as agitation speed, system temperature, SDS concentration, etc. As a result, optimum range of SDS concentration and temperature that could enhance the storage capacity and shorten the formation time were found. And it is obviously presented that SDS such a kind of surfactant promotes gas hydrate formation dramatically and the quantity of stored gas are proportional to agitation speed in stirred system.

• 대한기계학회논문집
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• 제8권6호
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• pp.517-525
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• 1984

본 연구에서는 2개의 축적탱크와 외부 열교환기로 구성된 가정용 태양열 급탕 시스템을 시뮬레이션 모델로 이론적인 해석을 하고 설계인자들의 값들을 변화시킴으로 써 각각의 성능을 계산할 수 있었다. 또 이 성능 계산치에 의하여 최적설계 인자치 들을 구할 수 있었다. 또한 1983년 1년간 서울지방의 매 시간 일분량과 기온을 사용 하였다.