• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2019년도 춘계 학술논문 발표대회
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• pp.120-121
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• 2019

In this study, FT-IR analysis was performed by exposing cement paste to high temperature in order to characterize the change of hydration behavior of concrete structure damaged by fire accident. As the holding time increased, the Al-O vibration region increased due to the increase of Si-O symmetric Ca₂(SiO₄) and Brownilerite, and the OH stretching region tended to increase due to thermal decomposition of Ca(OH)₂.

• 수산경영론집
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• 제30권2호
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• pp.25-37
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• 1999

Some multi echelon inventory systems carry perishable products. The value of these product reduces as the period of time they spend in the system. In this paper We derive the necessary condition to determine optimal quantity, service level for a perishable product. The systems considered consist of two echelons and carry single item. To determine the optimal order quantity, the demand is assumed to be constant, the holding costs may be different in the echelons, and it allows no shortages. I assumed the price of product decreases by negative exponential function. To determine service level, following assumptions used in the model ㆍlead time is constant. ㆍdemand is normal distribution. ㆍthe product starts to perish at the second echelon. Service level is computed for different levels of lead times and for different variance of demands and for different price functions. The experimental results indicate that the service level in cost is a function of service level in demand and perishability of product. Results of the models exhibit that perishability and the age of the product are critical to determine the lot sizing and service level.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.983-988
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• 2004

In the present study, the effects of orthogonal ribs on structural warpage during injection molding process were investigated. Basic ribbed models for the evaluation of degree of warpage were introduced and designed. Injection molds for these models are manufactured based on the full 3D CAD/CAM technology and specimens are prepared for experiment. Numerical analysis using commercial plastic injection molding analysis software was also performed to compare the results with experimental ones. The variations of materials and parameters such as injection time, mold temperature, melt temperature, holding time were considered in the present work. It was shown that orthogonal ribs have significant effect on the reduction of warpage during the injection molding process.

• 산업경영시스템학회지
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• 제33권1호
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• pp.71-79
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• 2010

This paper addresses capacity expansion planning model of distribution center under usability of public distribution center. For discrete and finite time periods, demands for distribution center increase dynamically. The capacity expansion planning is to determine the capacity expansion size of private distribution center and usage size of public distribution center for each period through the time periods. The capacity expansion of private distribution center or lease usage of public distribution center must be done to satisfy demand increase for distribution center. The costs are capacity expansion cost and excess capacity holding cost of private distribution center, lease usage cost of public distribution center. Capacity expansion planning of minimizing the total costs is mathematically modelled. The properties of optimal solution are characterized and a dynamic programming algorithm is developed. A numerical example is shown to explain the problem.

• 플랜트 저널
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• 제6권4호
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• pp.56-62
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• 2010

This study investigated characteristics of the post-weld heat treatment of SA213-T23, which was developed for water wall of the ultra super critical power boiler. The temperature of post weld heat treatment should be $730^{\circ}C$ or higher to reduce hardness of the deposit metal and heat affected zone. Coincidently, the temperature should remain $760^{\circ}C$ or lower to prevent hardness of the base metal from dropping. Hardness decline of deposit metal was trivial according to time when the holding time of heat treatment at $740^{\circ}C$ of post-weld heat treatment gradually increased from initial 15 minutes.

• 한국세라믹학회지
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• 제27권5호
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• pp.597-604
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• 1990

In Cubic ZrO2 crystal growth by Skull method, it was examined on effect of homonization on melt as keeping ZrO2(90mol%)-Y2O3(10mol%) melt with 1hr, 2hr, 4hrs, 8hrs, 16hrs, respectively. The optimum homonizing condition in this system was obtained by the examination between quality of grown crystals and soaking time of melt. It was obtained that the lower quality crystal could be produced in the longer holding melt than the optimum soaking time of melt in spite of the supposedly well homonized state, because the melt stability is sensibly dependent on the convective state of melt in skull method (cold crucible process).

• Journal of Information Processing Systems
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• 제6권4호
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• pp.575-596
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• 2010

Video-on-Demand services are increasing rapidly nowadays. The load on servers can be very high, even exceeding their capacity. For popular contents, we can use a Periodic Broadcast (PB) strategy using multicast to serve all clients. Recent development of PB uses multiple channels broadcasting for segments of movies in certain patterns, so that users only need to wait for a small segment to start the service. However, users need higher download capacity to download multiple segments at a time. In order to compensate for this, a proxy server can help to reduce download bandwidth requirements by holding some segments for a certain time. This research will focus on more recent PB schemes that couldn't be covered by previous Proxy-Assisted Periodic Broadcast strategies.

• 한국식품영양학회지
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• 제6권4호
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• pp.301-306
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• 1993

Effects of pressure and pressing time of soyprotein-CaSO4 coagulates on the yield, water holding capacity and textural characteristics of SPI (soy protein isolated) tofu were investigated. The tofu was prepared by addition of CaSO4 into SPI suspension at 9$0^{\circ}C$ and then compressed. As the compressing pressure increased from 8.66g /cm2 to 49.43g /cm2, the volume yield and moisture absorbed on filter paper were decreased and the textural properties of hardness, adhesiveness, cohesiveness and gumminess were increased. Increase in hardness and gumminess were more significant at high pressure than those at low pressure.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2011년도 춘계학술발표대회
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• pp.1033-1036
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• 2011

With the development of wireless networks and the use of mobile devices, mobile user's privacy issue is becoming more and more important. Privacy includes ID anonymity and unlinkability. Unlinkability requires that any two temporary IDs which have been used before should not be associated with each other. In other words, these temporary IDs should be generated in such a way that no direct relationship among them should be derived. The existing schemes only focus on ID anonymity of mobile users. In this paper, we proposed a scheme not only holding all the merits of previous works, but also achieving unlinkability which is guaranteed by using one-time-use temporary ID. And the mobile user can also updates its one-time-use temporary ID with the help of the visited foreign agent.

• 한국축산식품학회지
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• 제23권1호
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• pp.21-27
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• 2003

본 연구는 간장이 첨가된 돈육을 텀블링 및 침지 처리하여 염지하는 동안의 품질특성 변화를 조사하기 위하여 실시하였다. 침지한 처리구는 간장용액을 첨가 후 1$^{\circ}C$의 냉장상태에서 10분, 20분, 30분, 24시간, 48시간 경과한 후, 텀블링 처리구는 10분, 20분, 30분간 연속식으로 텀블링한 후 실험을 실시하였으며, 텀블링한 시료의 일부는 24시간 및 48시간 동안 냉장저장 후 pH, 육색, 제품수율, 가열수율, 보수력, 연도, 관능검사를 실시하였다. 가열전 텀블링 처리구와 침지 처리구의 pH는 차이가 없었으며, L-값은 가열 전.후 24시간 및 48시간 경과한 염지육에서 침지 처리구가 텀블링 처리구보다 낮은 값을 보였다. 제품 수율은 두 처리구 모두 염지 시간이 경과함에 따라 증가하였으며, 텀블링 처리구가 침지 처리구보다 높은 수율을 보였다. 또한 가열 수율도 텀블링 처리구가 침지 처리구보다 높게 나타났다. 텀블링 처리구의 보수력과 전단력은 텀블링 시간이 증가함에 따라 상승하였으며, 텀블링 처리구가 침지 처리구보다 연도상승 효과가 있었다. 관능평가에서 조직감, 다즙성, 전체적 기호도에서 텀블링한 처리구가 보다 높은 점수를 받았으나, 색, 풍미, 조직감, 다즙성, 짠맛, 전체적 기호도 항목에서 두 처리구간 염지시간에 따른 차이는 나타나지 않았다. 이상의 결과에서 텀블링 처리는 기존의 침지 처리에 비해 제품수율, 가열수율, 연도를 향상시킬 수 있었고, 30분 텀블링 후 24시간과 48시간의 지연시간이 경과한 경우에도 48시간 동안의 침지처리보다 우수한 제품을 제조할 수 있었다. 하지만 본 실험의 결과로 나타내지 않았으나 30분 이상 텀블링을 실시해 본 결과 시료의 일부가 찢겨지는 등의 문제가 발생되어 30분 이내에서의 텀블링이 유효할 것으로 판단된다.