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An Analytic Study of Cyber Security Strategies of Japan
Kyoungsik Min,Seung-Woan Chai 보안공학연구지원센터 2016 International Journal of Security and Its Applicat Vol.10 No.10
Japan has recently enacted the Fundamental Act on Cyber Security, taking prompt actions to reinforce the status of the cyber security policy and to organize the implementation system. This kind of change in policy indicates that cyber space does not remain as a field of information restricted to Internet but has become an international field of discussion about economy, society and politics. This study summarizes the change of cyber security policy of Japan, and analyzes the recent changes.
일본의 對동아시아 통상정책 변화와 추진방향에 관한 고찰
민경식(Kyoungsik Min) 한국무역연구원 2009 무역연구 Vol.5 No.3
Japan's trade policy until the 1980s, developed countries were the main interest. Japan's trade policy has largely focused on US relations. Since the 1990s, Japan's trade policy has changed significantly. The importance of trade policy in East Asia began to increase. For the emerging Chinese economy has also included the meaning of containment. Japan has supported the commerce policy of the free trade centering on WTO. However, the negotiation on WTO reached the limit and change of a commerce policy is needed. Recently, Japan is performing a positive trade policy to East Asia. Japan has already done FTA/EPA conclusion with some countries, and is continuing negotiation. Characteristics of Japan's trade policy is the promotion of economic integration in East Asia. This research describes a trade policy and FTA/EPA strategy of Japan. It is the purpose to draw the suggestive point in Korea which is promoting FTA now. In Chapter 2 the changes in Japan's trade policy analysis. In Chapter 3, FTA/EPA strategy for East Asia of Japan is described.
민선홍(Min, Sunhong),고형선(Koh, Hyungseon),유재현(Yoo, Jaihyun),정경식(Jung, Kyoungsik),이영진(Lee, Youngjin),최항석(Choi, Hangseok) 한국신재생에너지학회 2011 한국신재생에너지학회 학술대회논문집 Vol.2011 No.05
In this study, a test bed was constructed in order to evaluate thermal efficiency of the energy pile which carries out combined roles of a structural foundation and of a heat exchanger. The energy pile in this study is designed as a large-diameter drilled shaft equipped with the heat exchange pipes which configures a W-shape and an S-shape. The drilled shaft reached to the depth of 60 m whilst the heat exchange pipes were installed to about 30 m deep from the ground surface. The W-shaped and S-shaped heat exchange pipes were installed in the opposite sections of the same drilled shaft. In-situ thermal response tests were performed for both the shapes of heat exchange pipes. To avoid underestimating the thermal performance due to hydration heat of concrete inside the drilled shaft, the in-situ thermal response tests for the energy pile were performed after four weeks since the installation of the energy pile.
양문형 냉장고 내부 덕트 착상 방지를 위한 전산열유동해석
신승민(Seung-Min Shin),김병천(Byeong-Cheon Kim),장경식(Kyoungsik Chang),조용범(Yong Bum Cho),이상욱(Sang-Wook Lee) 대한기계학회 2021 대한기계학회 춘추학술대회 Vol.2021 No.6
본 논문에서는 양문형 냉장고에서 발생하는 착상(Frost)을 방지하기 위해 전산열유동해석을 이용하여 연구를 진행하였다. 냉동실에서 냉장실로 이동하는 유로에서 착상이 발생하며, 비정상해석을 통해 냉장고의 사이클을 고려하였을 때, 냉장실 내부 유동이 내부 덕트로 유입됨을 확인할 수 있었다. 유입된 유동의 유량을 감소시키기 위해, 3가지 냉장고 덕트 형상을 기존 형상과 전산열유동해석으로 비교하였다. 기존 모델에 base hole과 2nd hole을 추가한 모델을 적용하였을 때, 4번째 사이클(9분)동안 0.015kg으로 가장 적은 유량을 보였다. The present work was studied to prevent frost developed in a side-by-side refrigerator using CFD. The frost occurs in the flow path from the freezer to the refrigerator. There was an inflow of the fluid in the refrigerator into the inner duct when the cycle of the refrigerator was considered by unsteady Computational Flow analysis. To reduce the flow rate of the air from the fridge, three types of ducts were compared with the original model using CFD. The lowest flow rate of 0.015kg was observed in the duct that the base hole and 2nd hole were applied to the existing model.
민선홍,박상우,정경식,최항석,Min, Sunhong,Park, Sangwoo,Jung, Kyoungsik,Choi, Hangseok 대한토목학회 2013 대한토목학회논문집 Vol.33 No.3
본 연구에서는 현장타설 에너지파일의 열교환 파이프 배치 형태별 열교환율을 전산유체해석 프로그램(FLUENT)을 이용하여 평가하고, 이를 이용하여 에너지파일의 설계법을 제시하였다. 등가열교환율을 산정하기 위해 동일한 현장타설말뚝 제원에 대해 열교환파이프 배치 형태를 W-형(직렬), 복합 U-형(병렬 4쌍), 나선형의 3가지로 고려하였다. 건물측 부하조건은 여름철 냉방운용를 모사하기 위해 순환수의 에너지파일 유입온도, 즉 히트펌프 유출온도(Leaving water temperature, LWT)를 $35^{\circ}C$로 일정하게 유지하여 에너지파일 유출온도, 즉 히트펌프 유입온도(Entering water temperature, EWT) 변화를 관찰하였다. 지반에 최대 가상부하를 적용한 경우(100시간 연속 냉방부하 조건)에는 3가지 열교환기 형태가 유사한 열교환율을 보인 반면, 실제 히트펌프 가동에 의한 건물 냉방운용을 모사하기 위해 간헐적으로 일일 8시간 운용-16시간 정지를 7일간 반복 해석한 경우에는 W-형(직렬연결)과 복합 U-형(병렬 4쌍) 열교환기는 유사한 열교환율을 보이나, 나선형 열교환기는 파이프 루프 상호 간 열간섭으로 인해 복합 U-형 열교환기에 비해 약 86%의 열교환율을 갖는 것으로 평가되었다. 전산유체해석에 의해 계산된 열교환파이프 배치 형태별 에너지파일의 등가열교환율을 에너지파일 설계프로그램(PILESIM2)에 적용하여 다양한 형상의 현장타설 에너지파일에 대한 설계법과 대표적인 설계변수에 대한 설계도표를 제시하였다. In this paper, a relative heat exchange rate is numerically compared for cast-in-place concrete energy piles with different heat exchange pipe configurations, and a new design method for energy piles is proposed. An equivalent heat exchange rate was estimated for the W-type (one series loop), multiple U-type (four parallel loops), and coil-type heat exchanger installed in the same large-diameter drilled shaft. In order to simulate a cooling operation in summer by a CFD analysis, the LWT (leaving water temperature) into a energy pile was fixed at $35^{\circ}C$ and then the EWT (entering water temperature) into a heat pump was monitored. In case of continuously applying the artificial maximum cooling load for 100 hours, all of the three types of heat exchangers show the marginally similar heat exchange rate. However, in case of intermittently applying the cooling load with a cycle of 8 hours operation-16 hours off for 7 consecutive days, the coil type heat exchanger exhibits a heat exchange rate only 86 % of the multiple U-type due to measurable thermal interference between pipe loops in the energy pile. On the other hand, the W-type possesses the similar heat exchange rate to the multiple U-type. The equivalent heat exchange rates for each configuration of heat exchangers obtained from the CFD analysis were adopted for implementing the commercial design program (PILESIM2). Finally, a design method for cast-in-place concrete energy piles is proposed along with a design chart in consideration of typical design factors.
탄소나노튜브 및 함산소불화 탄소섬유분말 강화 에폭시 복합재의 기계적 특성
최예지(Ye Ji Choi),이경민(Kyeong Min Lee),김경식(Kyoungsik Kim),이영석(Young-Seak Lee) 한국고분자학회 2017 폴리머 Vol.41 No.5
에폭시 복합재는 그 기계적 특성을 향상시키기 위하여 탄소나노튜브와 함산소불화 표면처리된 탄소섬유 분말을 강화재로 사용하여 제조되었다. 탄소나노튜브와 탄소섬유분말 강화 에폭시 복합재는 탄소나노튜브 강화 복합재보다 비교적 높은 인장강도를 나타내었다. 또한 탄소나노튜브와 함산소불화 탄소섬유분말을 첨가하여 제조된 복합재는 미첨가 에폭시와 비교하여 인장강도 및 충격강도가 각각 최대 112%, 35% 향상되었다. 이러한 결과는 함산소불화에 의하여 탄소섬유분말 표면의 극성 및 거칠기가 상대적으로 향상되고 이에 따라 에폭시 수지와의 계면 접착력이 강화되어 나타난 결과로 사료된다. Epoxy composites are prepared using carbon nanotube (CNT) and oxyfluorinated powdered-carbon fiber (PCF) as reinforcements to enhance mechanical properties of composites. Tensile strength of PCF and CNT reinforced epoxy composites are relatively higher than that of epoxy composites reinforced CNT only. Also, the tensile and impact strength of epoxy composites added CNT and oxyfluorinated PCF are improved by respectively 112% and 35% than those of neat epoxy. These results are ascribed to increased interfacial adhesion of PCF with epoxy resin due to enhanced polarity and roughness of PCF-surface by oxyfluorination.
Nanomechanical Encoding Method Using Enhanced Thermal Concentration on a Metallic Nanobridge
Lee, Jeong Oen,Choi, Kwang-Wook,Choi, Seon-Jin,Kang, Min-Ho,Seo, Min-Ho,Kim, Il-Doo,Yu, Kyoungsik,Yoon, Jun-Bo American Chemical Society 2017 ACS NANO Vol.11 No.8
<P>We present a fast, energy-efficient nanothermomechanical encoding scheme for digital information storage and retrieval. Digital encoding processes are conducted by the bistable electrothermal actuation of a scalable nanobridge device. The electrothermal energy is highly concentrated by enhanced electron/phonon scattering and heat insulation in a sub-100 nm metallic layer. The efficient conversion of electrothermal energy into mechanical strain allows digital switching and programming processes within 60 ns at 0.75 V with a programming energy of only 54 pJ. Furthermore, this encoding scheme together with the thermally robust design enables data retention at temperatures up to 400 degrees C. These results suggest that the proposed nano-thermomechanical encoding method could contribute to low-power electronics and robust information storage/retrieval systems.</P>