• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.5A
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• pp.551-555
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• 2009

This study is performed to apply a standard to evaluate fire protection assessment for tunnel structures when a fire breaks out in the road tunnel. Recently, a number of road tunnels have been rapidly increased and fire risk also multiplyed according to extend tunnel length, due to natural features and environmentally-friendly road construction in Korea. But we have not yet been prescribed appropriate time-temperature curve for tunnel fire. Therefore, we presented fire design model and investigated time-temperature curve proposed by a foreign country considering traffic, a kinds of vehicles which are a basis of heat rate. At the end, Hydrocarbon modified curve applied as design fire model by using numerical analysis and presented design fire model and examined the effects of tunnel structures.

• Journal of Adhesion and Interface
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• v.13 no.3
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• pp.116-120
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• 2012

In this study, waterborne polyurethane was prepared from polyester polyol, $H_{12}MDI$, DMPA and sulfopropylated polypropyleneglycol-${\alpha}$,${\omega}$-diamine (SP). The $T_g$ of waterborne polyurethane was increased as the SP content increased, while it was decreased at the NCO/OH ratio of 1.8. Also the hydrolysis-resistance and tensile strength were increased as the SP content increased. The tensile strength decrement of WPU-SP was 2~5% with the exception of WPU-SP-1.

• Korean Journal of Food Science and Technology
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• v.23 no.4
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• pp.405-409
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• 1991

The polysaccharide was predominantly composed of glucose (79.60%), galactose (9.68%), mannose(8.67%), fructose (1.96%;) and xylose (0.09%). Major amino acid in protein was consisted of cystein, aspartic acid, valine and glutamic acid. The tumor growth inhibition ratio of the polysaccharide against Sarcoma 180 was at highest level of 64.96%, when administerd at the concentration of 50 mg/kg and life prologation ratio showed 28.91% at the concentration of 50 mg/kg. The direct cytotoxic effect of polysaccharide was not observed in the tumor bearing mice with Sarcoma 180 in vitro.

• Food Science and Preservation
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• v.5 no.3
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• pp.231-238
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• 1998

The effects of temperature(0, 5, 10 $^{\circ}C$), sawdust removal in root part and packaging conditions on the respiration and keeping qualities were evaluated. Higher respiratory activity, weight loss and stipe elongation were observed at higher temperature. Removal of sawdust part slowed down the rate of stipe elongation with little effect on the respiration rates, and therefore improve the quality preservation. The modified atmosphere packaging of 100g mushroom using hermetically sealing by 30 $\mu\textrm{m}$ polypropylene (CPP) and low density polyethylene (LDPE) films were effective in preserving the quality such as visual appearance and Hunter L value, and reducing weight loss at 0$^{\circ}C$, 5$^{\circ}C$ and 10$^{\circ}C$ compared to perforated packages.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.46 no.4
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• pp.79-86
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• 2009

In this paper, we propose a new clustering scheme that provides optimal data aggregation effect and reduces energy consumption of nodes by considering the density of nodes when forming clusters. Since the size of the cluster is determined to ensure optimal data aggregation rate, our scheme reduces transmission range and minimizes interference between clusters. Moreover, by clustering using locally adjacent nodes and aggregating data received from cluster members, we reduce energy consumption of nodes. Through simulation, we confirmed that energy consumption of the whole network is minimized and the sensor network life-time is extended. Moreover, we show that the proposed clustering scheme improves the performance of network compared to previous LEACH clustering scheme.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.8 s.350
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• pp.77-83
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• 2006

In this paper, we have pesented a reliable data transfer mechanism using Directed Diffusion in WSNs (fireless Sensor Networks). This mechanism involves selecting a route with higher reachability and transferring data along the route chosen, which is based on the end-to-end reliability calculated by the dissemination procedure of Interest packets, while each node of a sensor network maintains the only information on its neighborhood. We performed various experiments changing the link error rates and the number of nodes and discovered that this proposed mechanism improves event-to-sink data transfer reliability in WSNs. We also found that this mechanism spreads traffic load over and reduces energy consumption, which in turn prolongs network lifetime.

• Korean Journal of Poultry Science
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• v.20 no.1
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• pp.33-41
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• 1993

Among the several factors that affect shelf-life of washed shell eggs, storage temperature and relative humidity were the most important. Besides those factors listed above, temperature of washing water, composition of foreign substances and washing method of eggs were also the factors affecting the shelf-life of the eggs. The effect of sanitizer treatment was significant in extending the shelf-life of eggs compared with washed and unwashed eggs. In case of oil coating treatment, the shell eggs treated showed the better results than that of washed and unwashed eggs because the coating materials prevented the moisture evaporation from the inner shell eggs and kept the contamination of microorganisms from the environment. Consequently, it is considered that reducing egg shell contamination of microorganisms and proper treatment could be the key to extend the shelf-life of shell eggs.

• Journal of the Korean Applied Science and Technology
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• v.32 no.1
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• pp.100-107
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• 2015

Prepared polyurethane resin for vegetable leather coating on surface was synthesized with glycerol which had different mole ratio. Mechanical properties of the synthesized polyurethane resin were measured by the SEM, FT-IR, UTM. Growing concerns in the evnironment-friendly polymer resin, we have synthesized low late obtained solvent water dispersion resin to be coating on vegetable leather. The increase of aliphatic trihydric alcohol glycerol mole %, abrasion resistance and tensile strength had highly stronger in intensity and longer durability. On the contrary, demonstrated reduce properties of elongation and flexibility. In the result of toluene solvent resistance, there was no effect of increased or decreased by the ratio of glycerol mole %.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.10a
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• pp.369-372
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• 2008

무선 센서 네트워크(WSN)는 소규모, 저비용, 저전력 지능형의 센서 노드로 구성되고, 원격 환경 감시와 군사작전 및 재난 상황 등에 응용 될 수 있는 기술이다. 이러한 센서 네트워크에서 구성된 노드의 에너지 공급은 독립된 소형배터리를 통해 이루어진다. 따라서 각 노드에서의 에너지의 효율적인 관리가 무선 센서 네트워크의 최대 쟁점이 되고 있다. 본 논문에서는 이러한 노드의 제한된 배터리 자원을 보다 효율적으로 유지 관리하기 위한 방법으로 ASIT(Advanced Sensing Interval Time) 알고리즘을 제안한다. 제안된 ASIT란 입력된 센싱 값의 변화와 센서 노드의 에너지 잔여량에 따라 센싱 주기를 제어 관리하는 방법으로 이에 대한 모델링을 수립하고, 실제 노드 관리 결과와 모델링 된 결과의 오차를 관찰하여 적중율을 향상하는 기법을 제안한 것이다. 제안된 ASIT의 알고리즘으로부터 센서 노드의 수명을 향상 시켜 궁극적으로는 무선 센서 네트워크 전체의 망 접속의 신뢰성과 노드 관리 수명을 연장시키며, 망의 토폴로지 구성의 측면에서는 전체적인 영역의 커버리지를 향상시키는 동시에 제한된 배터리 자원을 효율적으로 관리 할 수 있는 걸과를 얻게 된다.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.116-116
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• 2010

진공 chamber에서 방전된 plasma 내부를 외부 view port를 통하여 확인하는 것은 극히 제한적이며 leak의 확률을 높이고 plasma의 균일한 방전을 방해한다. 이를 개선하기 위하여 내장형 무선 카메라를 chamber 내부에 위치한 후 고진공 영역에서 촬영을 시도하였으나 일반적인 CCD 카메라로는 촬영할 수 없다. 고진공 영역에서 카메라 내부온도의 급격한 상승이 원인으로 밝혀졌고 적정온도인 $45^{\circ}C$를 초과하여 최대 $96^{\circ}C$까지 4 min 이내에 상승함을 IR camera로 확인할 수 있었으며 이 때 카메라가 작동하지 않았다. 또한 카메라를 고진공 영역에서 촬영 및 녹화하기 위해서는 $46^{\circ}C$의 온도를 낮추어야 함을 진공해제 이후 내부온도가 $50^{\circ}C$로 감소하면서 내장형 무선 카메라가 다시 작동함으로 인해 알 수 있었다. 본 연구에서는 이를 해결하기 위하여 내장형 무선 카메라에 AM 변조 방식의 311 MHz RF remote controller를 장착하여 외부에서 선택적으로 ON/OFF 할 수 있도록 개조하였고 10 L chamber에서 150 L/sec TMP를 이용하여 10-6 Torr의 압력에서 성공적으로 녹화 및 촬영하였다. 또한 내장형 무선 카메라 내부의 반도체 회로 규격 및 발열량과 heat sink의 규격 (열전도도, 복사율)을 추가로 조사하였다. 분자유동 영역에서 열전달은 복사에 의한 영향이 대부분이므로 내장형 무선 카메라 내부 온도를 감소시켜 카메라의 작동 시간을 연장하기 위하여 내부 회로에 emissivity가 높고 전기전도도가 낮아 회로에 영향이 없는 박막을 회로에 증착시키는 추후의 연구가 필요하다.