• Fire Science and Engineering
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• v.12 no.4
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• pp.21-30
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• 1998

The safety of LPG vessel storage has been simply designed and controled with blast wave barrier structure concept regardless of its quantity or hazardous situation. The limit of regal controls on LPG vessel storage need to be identified in terms of safety buffer distance from LPG explosion. The level of overpressure effect and heat radiation to the neighbouring structure and human activity required to be estimated to find the gap between existing controls on such storage. PHAST and IAEA manual for risk rankings and assessment had been applied to get the required safety distance for neighbouring facilities, Japanese legal control for such facilities were also investigated. To this context the issues on LPG vessel storage required additional safety distance between existing blast wave barrier structure and safety separation distances.

• Journal of the Korea Society for Simulation
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• v.21 no.2
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• pp.91-101
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• 2012

Automobile manufacturing consists of body-line, painting-line, and assembly-line. These production lines are disposed in series and go through a flow process, so according to the status of pre & post processing, a suspension happens in a line by a starvation(impossibility of production by insufficient supply) or blocking(impossibility of production by exceed capacity). Therefore, to prevent a loss of production coming from a starvation or blocking, a storage such as WBS or PBS is independently owned and operated. The paper suggests the simulation model of integrated storage which can operate it by integrating each storage performing a role as a buffer of line. Specifically, the paper found the answers about reasonable number of Stacker Crane and AGV(Automatic Guided Vehicle) and suggested a methodology of operation which is available to operate them. Also, it compared an efficiency between a model of current storage and integrated storage through simulation. As a result, it turned out that the model suggested in the paper was more efficient on suspension of painting-line stop than a current storage.

• Journal of the Korean Society of Food Science and Nutrition
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• v.18 no.1
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• pp.115-122
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• 1989

The mechanisms of aflatoxin $B_1(AFB_1)$ degradation by ammonia and alkaline pH during the storage of Korean soy sauces were studied. In the 0.05%, 0.1% and 0.5% of ammonia solutions, almost all of $AFB_1$(96-100%) was degraded after 2 to 24 hrs of incubation at $30^{\circ}C$. Increased levels of ammonia in both home made soy sauce(HMSS) and commercial soy sauce(CSS) caused slow increases in pH. The pH change was higher in CSS than in HMSS. The degradations of $AFB_1$ were not observed in the samples of HMSS, CSS, distilled water and 20 % of NaCl solution during the storage, however, when the pHs of the samples were adjusted to 10, the toxin was completely removed in all samples. $AFB_1$ was stable at pH 5 and 7 in bath buffer solutions and buffer solutions+0.2% ammonia, however, $AFB_1$ was degraded completely at pHs more than 9. $AFB_1$ was not degraded even at high concentrations of ammonia(0.2-1.0%) when the pH was maintained at 7 in the buffer solution. It indicated that ammonia content in the system was not important but the higher pH was the reason to degrade $AFB_1$. When the pHs of HMSS, CSS, buffersolution and buffer solution + 0.2% ammonia were adjusted to 5 and then reacted with $AFB_1$ for 5 days, the toxin was stable in all samples. However, when the pHs of the samples were adjusted to 7, about 60-70 % of $AFB_1$ was degraded in HMSS and CSS after 5 days of incubation during which the pH was not changed, but $AFB_1$ in the buffer solution and buffer solution + 0.2% ammonia was not degraded at all in the same conditions.

• Korean Journal of Food Science and Technology
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• v.36 no.6
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• pp.857-862
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• 2004

Effects of frying temperature and time, presoaking in distilled water, various pH buffer solutions, and storage temperature of french fries on acrylamide formation were investigated. Acrylamide concentration in french fries increased as frying temperature and time increased. Presoaking of raw potatoes in distilled water reduced acrylamide formation compared to those without presoaking. Acrylamide formation of fried potatoes after presoaking at $60^{\circ}C$ for 45 min was about 16% of that without presoaking. Presoaking treatment of raw potatoes in various buffer solutions showed acrylamide concentrations of french fries from potatoes presoaked in acidic buffer solutions were lower than those from potatoes presoaked in neutral to alkaline buffer solutions. Acrylamide concentration of potatoes stored at refrigerator temperature was much higher than those stored at room temperature.

• Journal of agriculture & life science
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• v.44 no.3
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• pp.15-21
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• 2010

We estimated the biomass productivity and the storage potential of nitrogen, the major contributor of non-point source pollution, with four three-year-old four poplar clones in a riparian woody buffer established in the Anseong River in Anseong, Korea. Stem of Populus alba ${\times}$ P. glandulosa clone 72-31 and Populus deltoides ${\times}$ P. nigra clone Dorskamp showed the highest percentage of aboveground biomass components, followed by branch and leaf. Nitrogen content in aboveground biomass components of two poplar clones was the highest in leaf and the lowest in stem. Nitrogen content in leaf and branch of clone 72-31 was higher than that of clone Dorskamp, while it in stem was lower. Populus deltoides clone Ay48 showed the highest above-ground biomass productivity, which was estimated as $37.5ton\;ha^{-1}$ at age 3. However, clone 72-31 was the lowest in above-ground biomass productivity. Nitrogen storage potential in aboveground biomass of 3-year-old poplar clones was high in order of aboveground biomass. Clone Ay48 showed the highest nitrogen storage potential in aboveground biomass, which was estimated as $218.3kg\;ha^{-1}$ at age 3.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.9B
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• pp.751-759
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• 2003

We analyze the performances, such as the cell loss probability(CLR) and the cell delay time, of time division multiplexed(TDM) optical output buffers using traveling delay lines or delay-line loops for buffering. Since traveling delay lines used for buffering are superior over delay-line loops in terms of simplicity and signal quality, they were used in a conventional TDM optical output buffer. However, the latter is more flexible than the former in that the cell storage time is adjustable by changing the recirculating times of a cell in the loops. So we propose a novel TDM optical output buffer using delay-line loops for buffering. We show that the proposed TDM optical output buffer can reduce the number of buffering unit required to achieve a CLR of less than 10$^{-9}$ . When the number of buffering unit is sufficiently large, we show that both TDM optical output buffers have same cell delay time characteristic.

• Journal of the Microelectronics and Packaging Society
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• v.28 no.3
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• pp.17-24
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• 2021

Perovskite solar cells (PSCs) can be fabricated through solution process economically with variable bandgap that is controlled by composition of precursor solution. Tandem cells in which PSCs combined with silicon solar cells have potential to reach high power conversion efficiency over 30%, however, lack of long-term stability of PSCs is an obstacle to commercialization. Degradation of PSCs is mainly attributed to the mass transport of halide and metal electrode materials. In order to ensure the long-term stability, the mass transport should be inhibited. In this study, we confirmed degradation behaviors due to the mass transport in PSCs and designed buffer layers with LiF and/or SnO₂ to improve the long-term stability by suppressing the mass transport. Under high-temperature storage test at 85℃, PSCs without the buffer layers were degraded by forming PbI₂, AgI, and the delta phase of the perovskite material, while PSCs with the buffer layers showed improved stability with keeping the original phase of the perovskite. When the LiF buffer and encapsulation were applied to PSCs, superior long-term stability on 85℃-85% RH dump heat test was achieved; efficiency drop was not observed after 200 h. It was also confirmed that 90.6% of the initial efficiency was maintained after 200 hours of maximum power tracking test under AM 1.5G-1SUN illumination. Here, we have demonstrated that the buffer layer is essential to achieve long-term stability of PSCs.

• Communications of the Korean Mathematical Society
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• v.10 no.3
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• pp.715-733
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• 1995

We present a transient queue size distribution for $M/G/m/N$ queue with state dependent arrival rates, using the diffusion process with piecewise constant diffusion parameters, with state space [0, N] and elementary return boundaries at x = 0 and x = N. The model considered here contains not only many basic model but the practical models such as as two-node cyclic queue, repairmen model and overload control in communication system with finite storage buffer. For the accuracy check, we compare the approximation results with the exact and simulation results.

• Proceedings of the Korean Information Science Society Conference
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• 2001.10c
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• pp.97-99
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• 2001

대용량 데이터 및 사용자간 데이터 공유의 증가로 네트워크 저장 서버의 필요성이 증대되고 있다. 리눅스는 네트워크 저장 서버의 운영체제로 널리 사용되고 있지만 디스크 쓰기 성능에 큰 영향을 미치는 버퍼 플러쉬 정책이 다양한 디스크 입출력 부하에 적합하도록 되어 있지 않다. 본 연구에서는 효율적인 리눅스 기반 네트워크 저장 서버를 위한 디스크 입출려 부하에 따른 적응 제어 버퍼 플러쉬 정책을 제안한다.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1998.03a
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• pp.209-213
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• 1998

This study considers flowshop scheduling problem related to flexible maufacturing cell in which consists of two machining centers, robots for loading/unloading, and an automated guided vehicle(AGV) for material handling between two machining centers. Because no machinng center has buffer storage for work in process, a machining center can not release a finished job until the empty AGV is available at that machining center. While the AGV cannot tranfer an unfinished job to a machining center until the machining center empty. In this paper, an new heuristic algorithm is given to find the sequence that minimize their makespan.