• 설비공학논문집
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• 제17권11호
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• pp.1050-1059
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• 2005

Heat and $SF_6$ gas dispersions over a complex terrain were investigated using wind tunnel. The wind speed, temperature and concentration profiles were measured for the 1/1000 scale complicated terrain model in an Eiffel type boundary layer wind tunnel with test section of 2.5m in height and 4.5m in width. The scale model was mounted on the top of a plate which can rotate with respect to the approaching wind. Dispersion processes from a continuous emission source driven by various wind direction were investigated, including plume climbing over the steep up-slope of the mountain and down-spreading toward the lower level of the valley. Extensive dispersion experiment data (wind speeds and concentration profiles) were provided for verification and validation of dispersion models. Under the identical flow and emission conditions, the independently measured profiles of the temperature and $SF_6$ concentration showed an excellent agreement which ensured the credibility of the results.

• 대한기계학회논문집B
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• 제24권9호
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• pp.1195-1209
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• 2000

The purpose of this study is to develop the non-gravity fluidized dryer. In this non-gravity fluidized dryer the fluidized zone is produced by two paddles in mixer, which maximizes the surface area of materials and then heated air through the guiding panels dehumidify them. This can conduct the drying process quickly and control moisture contents to lower limits. The ventilation system is closed loop system, which can be changeable to open system, and can be used as a multi-purposed dryer in which mixing, drying, granulating and cooling process is conducted. In order to develop the non-gravity fluidized dryer, in the first fundamental experiments were performed to mixing accuracy and then the other parts of dryer and control system were examined to check whether they were designed properly and operated harmoniously with mixer. Also the preparatory experiments were fulfilled to examine the efficiency and reliability of the dryer. Lastly, on the basis of preparatory experiments, performance test for the non-gravity fluidized dryer carried out for the variation of the initial moisture contents, desired moisture contents, heated air velocity and heating temperature.

• The Korean Journal of Ecology
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• 제25권5호
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• pp.321-328
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• 2002

등산객에 의한 많은 간섭을 받아온 설악산 대청봉의 아고산생태계에서 훼손된 식생의 복원에 필요한 기초자료를 제공하기 위하여 인간에 의한 답압에 따른 입지인자와 식생의 변화를 파악하였다. 본 조사지역에서 인간에 의한 간섭은 경사도 10° 미만의 완만한 남사면 지역에서 두드러졌다. 인간의 간섭은 식생의 키. 식피율 및 종다양성을 감소시켰고, 식생의 종조성의 변화를 통하여 식생구조의 변화를 유발하였다. 또한 인간의 간섭은 파괴된 식생으로 인한 낙엽생산이 감소하고, 고산지대 특유의 바람에 의한 낙엽의 이동으로 인하여 낙엽층과 유기물층의 발달이 저해되었다. 이는 토양수분함량을 감소시키고, 토양침식작용이 활발해져 토심이 얕아지고 표토층이 유실되면서 자갈이 지표면에 노출된 입지환경으로 변화시켰다.

• 한국대기환경학회지
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• 제19권4호
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• pp.397-414
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• 2003

The performance of one-particle stochastic Lagrangian models for passive tracer dispersion are evaluated against measurements in horizontally-homogeneous neutrally-stratified atmospheric surface layer. State-of-the-technology models as well as classical Langevin models, all in class of well mixed models are numerically implemented for inter-model comparison study. Model results (far-downstream asymptotic behavior and vertical profiles of the time averaged concentrations, concentration fluxes, and concentration fluctuations) are compared with the reported measurements. The results are: 1) the far-downstream asymptotic trends of all models except Reynolds model agree well with Garger and Zhukov's measurements. 2) profiles of the average concentrations and vertical concentration fluxes by all models except Reynolds model show good agreement with Raupach and Legg's experimental data. Reynolds model produces horizontal concentration flux profiles most close to measurements, yet all other models fail severely. 3) With temporally correlated emissions, one-particle models seems to simulate fairly the concentration fluctuations induced by plume meandering, when the statistical random noises are removed from the calculated concentration fluctuations. Analytical expression for the statistical random noise of one-particle model is presented. This study finds no indication that recent models of most delicate theoretical background are superior to the simple Langevin model in accuracy and numerical performance at well.

• Journal of Radiation Protection and Research
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• 제10권1호
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• pp.3-13
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• 1985

주요 핵분열 생성물인 세슘-137, 장수명 핵종과 세륨-144, 희토류원소 그리고 부식 생성물인 코발트-60등의 제올라이트 A, 제올라이트 F-9(Faujasite) 그리고 비정형 제올라이트에 대한 흡착거동을 염농도 0.01 M부터 2.0 M 질산과 질산암모늄 그리고 교반시간 15분부터 90분까지 15분 간격으로 검토하였다. Kd 값은 Batch 실험방법으로 구했다. 결론으로 주요핵종의 분리 제거의 최적조건은 비정질 제올라이트, 0.01 M-질산과 0.1 M-질산암모늄, pH 4, 교반시간 한시간 그리고 가장 효율높은 핵종은 세슘 -137이다.

• 한국대기환경학회지
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• 제34권5호
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• pp.697-707
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• 2018

A fast running model comprising the climate change effects is proposed for urban heat environment simulations so as to be used in urban heat island studies and/or the urban planning practices. By combining Hot City Model, a high resolution urban temperature prediction model utilizing the Lagrangian particle tracing technique, and the numerical weather simulation data which are constructed up to year of 2100 under the climate change scenarios, an efficient model is constructed for simulating the future urban heat environments. It is applicable to whole city as well as to a small block area of an urban region, with the computation time being relatively short, requiring the practically manageable amount of the computational resources. The heat environments of the entire metropolitan Seoul area in South Korea are investigated with the aid of the model for the present time and for the future. The results showed that the urban temperature gradually increase up to a significant level in the future. The possible effects of green roofs on the buildings are also studied, and we observe that green roofs don't lower the urban temperature efficiently while making the temperature fields become more homogeneous.

• 한국습지학회지
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• 제10권3호
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• pp.133-139
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• 2008

도심하천은 도심개발과 오염으로 인해 기능이 점차 상실되고 있다. 본 연구는 도림천의 출현 동물상 및 식물상을 파악하여 도심하천의 건강성을 평가하는 지표종을 발굴하고, 습지보전지역의 가능성을 위한 방안을 토론하였다. 도림천에서 안양천에 이르는 구간에 총 113종의 식물종, 포유류 9종, 조류 23종, 양서류 4종, 파츙류 2종과 어류 2종이 관찰되었다. 육상곤충은 71종이 관찰되었으며, 습지식생은 매우 다양하며 총 4개의 권역으로 나누었으며, 도심하천의 특징을 나타내는 수변지역 및 습지식물권역(습지식물권역, 반습지식물권역, 습지주변초지 지역, 습지주변교목지역)에 대한 관리방안이 도출되었다.

• 한국환경과학회:학술대회논문집
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• 한국환경과학회 2007년도 춘계 학술발표회 발표논문집
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• pp.157-161
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• 2007

최근에 설치된 마산기상대의 windprofiler의 기기보정을 위한 비교관측을 하기에 앞서 마산기상대의 기상 관측자료를 이용하여 마산지역의 기후 변화 현황을 알아보았다. 그 결과, 마산지역은 최근 5년간 평년에 비하여 건조해졌으나 연강수량과 강수강도는 약한 증가현상을 나타내었다. 그리고 $20^{\circ}C$의 기온빈도가 증가하여 마산지역이 상당히 따뜻해 진 것으로 나타났다. 마산연보(2006)에 의하면 마산시에는 자동차 등록 수는 매년 증가하여 2005년 현재 138,241대를 나타내어 도시화로 인한 인공열원이 증가하였다고 볼 수 있다. 그렇지만 인구는 1998년 435,343명을 최고치로 나타낸 이후 매년 감소하는 추세를 보이고 있으며 사업체수 역시 1995년 35,622개 이후 점차 감소하고 있는 추세이다. 더불어 도심지 공원은 2005년 현재 91개까지 증가하였으며 공원 총면적 또한 2001년 이후 계속 증가하고 있는 추세이다. 마산지역의 기온이 $1985{\sim}2005$년 평년치보다 최근 5년간 상당히 따뜻해졌지만 자동차로 인한 인공열원의 증가가 인구 및 사업체 감소, 도심지 공원수와 면적 및 해풍 빈도의 증가와 상쇄되어 도시화의 영향이 다소 약하게 나타났으나 지구온난화와 더불어 마산지역의 기온도 상승하고 있음을 알 수 있다. 향후 지구온난화에 대한 영향을 지속적으로 조사할 필요가 있을 것으로 생각된다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2014년도 춘계 학술논문 발표대회
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• pp.80-81
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• 2014

Generally significant reinforcement is used for nuclear power plant structures and may cause potential problems when concrete is poured. In particular pouring concrete into structural member joint area is more difficult than other areas since the joint area is very congested due to hooked bars, embedded plates, and other reinforcements. The purpose of this study is to solve the problem by applying high-strength(ASTM A615 Gr. 75/80) bars. In addition large-sized(#14 & #18) headed deformed bar could be used as alternative of standard hooked bars to relieve the congestion to some extent. In order to apply headed deformed bars to nuclear power plant structures effectively, the large-sized diameter bars and the high-strength bars shall be used as thick as clear cover thickness 1". Therefore, test results were obtained by taking bar size, yield strength, and clear cover thickness as variables.

• KIEAE Journal
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• 제11권1호
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• pp.29-38
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• 2011

This study suggested practical application of climate design on apartment complex with the focus on the use of Cold Air Flow and green building design method. The domestic research on the wind path analysis has been associated since the early 21th century in urban planning and site planning, this initiative study aimed to mitigate the urban heat island effect and to promote the sustainable urban development. It is, however, mostly focused on the flow analysis and heat flow in the urban context, due to the poor application of the wind path analysis in actual planning and design. Special attention is paid to the possibilities of identifying and developing the application methods in relation to Cold Air Flow and building design. This study examined these relations and suggested some trenchant approach to a more comprehensive and efficient use of the wind flow analysis in climate design.