• Journal of architectural history
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• v.21 no.1
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• pp.83-98
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• 2012

The starting point of this study is the concerning of simple behavioral pattern that whoever enters the inner space with taking off his shoes should go out from the position where he laid his shoes. The using of Ondol (floor heating room) and Maru (lifted wood floor) had changed the architectural space from chair-sitting to floor-sitting space, and it also made the behavior of taking off the shoes at the entrance of building and stepping on the lifted floor. This simple behavior has possibility to make lots of changes to the culture of architectural design. With this noticeable point, this paper is talking about the cultural feature of Korean traditional architecture, especially about the influence of tanking off and putting on shoes. The matter of shoes has changed diverse aspects of building and layout planning. It maximized the difference between front and rear part of building and characterized the lateral extension of Korean traditional house. The ritual space also had evolved from chair-sitting to floor-sitting space according to the type of ritual behavioral pattern. The change on the single building level had influenced on the layout planning of architectural complex. For examples, the parallel layout of ChangDeok-gung palace and the long sequential process to the main pavilion of Buddhist temple are the result of the matter of shoes. And NuGak(樓閣), the double-storied pavilion, on the axis of entering sequence's node is one of the unique planning elements that makes possible to go through the building without taking off the shoes and also makes upper level space for staying. In short, Korean traditional architecture that has the chair-sitting spatial origin of the East Asian cultural sphere has pursued new architectural issues and planning methods according to evolution to the floor-sitting culture.

• Journal of the Earthquake Engineering Society of Korea
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• v.20 no.7_spc
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• pp.453-460
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• 2016

The Gyeong-Ju earthquake in the magnitude of 5.8 on the Richter scaleoccurred in September 12, 2016. Because there are many nuclear power plants (NPP) near the epicenter of the Gyeong-Ju earthquake, the seismic stability of nuclear power plants is becoming a social problem. In order to evaluate the safety of seismically isolated NPP, the seismic response of a NPP subjected to the Gyeong-Ju earthquake was compared with those of 30 sets of artificial earthquakes corresponding to the nuclear standard design spectrum (NSDS). A 2-node model and a simple beam-stick model were used for the seismic analysis of seismically isolated NPP structures. Using 2-node model, the effect of internal temperature rise, decrease of shear stiffness, increase of lateral displacement and decrease of vertical stiffness according to nonlinear behavior of lead-rubber bearing (LRB) were evaluated. The displacement response, the acceleration response, and the shear force response of the seismically isolated nuclear containment structure were evaluated using the simple beam-stick model. It can be observed that the seismic responses of the isolated nuclear structure subjected to Gyeong-Ju earthquake is significantly less than those to the artificial earthquakes corresponding to NSDS.

• Journal of the Korea institute for structural maintenance and inspection
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• v.25 no.6
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• pp.103-110
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• 2021

Elastomeric bearings composed of flexible rubber materials and steel reinforcement plates are widely used for seismic retrofit of bridges due to their excellent vertical stiffness and flexible lateral stiffness. Especially, it has the advantages of simple construction and low cost. Chloroprene rubber, a type of rubber material, has greater resistance to aging than natural rubber, but its performance is also degraded due to various deterioration factors. Although these aging characteristics are not reflected in the seismic design standards and seismic performance evaluation guidelines, it is reasonable to reflect this when related studies are accumulated. For chloroprene rubber, accelerated heat aging test was performed with variables of heating temperatures and exposure time to analyze shear characteristics. As aging progresses the maximum shear stress and shear strain decrease. Also, the shear stiffness is greatly increased at the same shear strain.

• Computers and Concrete
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• v.26 no.6
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• pp.467-482
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• 2020

This research focused on analyzing the post-fire behavior of high-performance concrete-filled steel tube (CFST) columns, with the concrete containing tire rubber and steel fibers, under axial compressive loading. The finite element (FE) modeling of such heated columns containing recycled aggregate is a branch of this field which has not received the proper attention of researchers. Better understanding the post-fire behavior of these columns by measuring their residual strength and deformation is critical for achieving the minimum repair level required for structures damaged in the fire. Therefore, to develop this model, 19 groups of confined and unconfined specimens with the variables including the volume ratio of steel fibers, tire rubber content, diameter-to-thickness (D/t) ratio of the steel tube, and exposure temperature were considered. The ABAQUS software was employed to model the tested specimens so that the accurate behavior of the FE-modeled specimens could be examined under test conditions. To achieve desirable results for the modeling of the specimens, in addition to the novel procedure described in this research, the modified versions of models presented by previous researchers were also utilized. After the completion of modeling, the load-axial strain and load-lateral strain relationships, ultimate strength, and failure mode of the modeled CFST specimens were evaluated against the test data, through which the satisfactory accuracy of this modeling procedure was established. Afterward, using a parametric study, the effect of factors such as the concrete core strength at different temperatures and the D/t ratio on the behavior of the CFST columns was explored. Finally, the compressive strength values obtained from the FE model were compared with the corresponding values predicted by various codes, the results of which indicated that most codes were conservative in terms of these predictions.

• Transactions of the Korean hydrogen and new energy society
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• v.25 no.6
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• pp.648-655
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• 2014

This paper describes the continuing effort to develope a single acting free-piston Stirling engine/alternator combination for use of the household cogeneration. Free piston Stirling engines(FPSE) use variations of working gas pressure to drive mechanically unconstrained reciprocating elements. Stirling cycle free-piston engines are driven by the Stirling thermodynamic cycle which is characterized by an externally heated device containing working gas that is continuously re-used in a regenerative, reversible cycle. The ideal cycle is described by two isothermal process connected by two constant volume processes. Heat removed during the constant volume cooling process is internally transferred to the constant volume heating process by mutual use of a thermal storage medium called the regenerator. Since the ideal cycle is reversible, the ideal efficiency is that of Carnot. Free-piston Stirling engine is have no crank and rotating parts to generate lateral forces and require lubrication. The FPSE is typically comprised of two oscillating pistons contained in a common cylinder. The temperature difference across the displacer maintains the oscillations, and the FPSE operate at natural frequency of the mass-spring system. The power is generated from a linear alternator. The purpose of this paper is to describe the design process of the single acting free-piston Stirling engine/alternator. Electrical output of the single acting free-piston Stirling engine/alternator is about 0.95 kW.

• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.3
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• pp.503-515
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• 2017

Underground structures that have recently become larger are required to be stable not only during normal times but also during earthquakes. Especially, it is very important to maintain the stability of the subsea tunnels during the earthquake. The objective of this paper is to verify the effectiveness of the flexible segment, which is one of the breakthrough facilities to maintain the stability of the subsea tunnel during the earthquake using the shaking table test. Another goal of this paper is to propose the optimum position of the flexible segment through 3D dynamic numerical analysis based on the verified results from shaking table tests. The 1g shaking table test considering the similarity ratio (1:100) to the cross section of the selected artificial subsea tunnel was carried out considering the Geongju and Artificial seismic waves, longitudinal and lateral wave, and with/without flexible segments eight times or more. As a result of the shaking table test, it was confirmed that the flexible segment is effective in improving the seismic performance of the undersea tunnel in all the experimental results. In addition, 3D dynamic numerical analysis was performed to select the optimum position of the flexible segment which is effective for improving seismic performance. As a result, it was confirmed that the seismic acceleration is attenuated when the flexible segment is installed adjacent to the branch section in subsea tunnel.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.2
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• pp.196-202
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• 2008

To establish a cultivation system of Sedum sarmentosum using a rice nursery tray ($30{\times}60{\times}3\;cm$) in non-heating plastic film house, cuttings of two local strains (Wanju and Keumsan) were prepared and planted at different planting densities (40, 60 and 80 cuttings per tray) on September 7th, and subsequent growth and yield at pre- and post-winter season were investigated. When pre-wintering growth were measured at 60 days after planting, high planting density (80 cuttings/tray) decreased leaf length and lateral shoot number per plant compared to 40 cuttings/tray. When post-wintering growth were measured on April 20th, no significant growth differences as affected by planting density were observed in Keumsan strain, while decreased stem diameter, node number and leaf number were observed in Wanju strain planted at 80 cuttings/tray compared to 40 cuttings/tray. Fresh and dry weights were not significantly different as affected by planting density, but those were significantly increased in Wanju strain compared to Keumsan strain. When regrowth characteristics followed by the first harvest were measured on June 5th, significantly increased stem number was observed at 80 cuttings/tray compared to 40 cuttings/ tray. Fresh and dry weight were significantly increased in Keumsan strain planted at 80 cuttings/tray compared to 40 cuttings/tray, and dry weight were increased in Wanju strain compared to Keumsan strain. Wanju strain showed higher shoot yield, thicker stem, shorter node and larger leaf, and non-succulent stem under high planting density compared to Keumsan strain. Accordingly, the optimum density was 40 cuttings per tray, and Wanju strain was adequate for the cultivation system using a rice nursery tray.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2001.04b
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• pp.71-72
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• 2001

최근 수출오이의 재배 면적이 계속증가 추세에 있어 '99년 현재 143ha에 달하고 있다. 그러나 수출오이는 국내 오이와 재배방법이 상당히 달라 국내 오이는 주지착과형이지만 수출오이는 측지착과형으로 측지의 발생여부에 따라 수확량의 차이가 심하다. 따라서 수출오이의 성공여부는 측지발생을 어느정도 시키느냐에 달려 있다고 해도 과언이 아니다. 그런데 수출오이의 재배시기는 우리나라에서 재배환경이 가장 불량한 겨울철(10-2월)로, 저온 및 투광량 부족 등으로 인하여 측지발생율이 매우 저조하다. 따라서 본 시험은 수출오이의 측지 발생율을 높이고자 지중가온기 설치 여부에 따른 효과를 구명하고자 실시하였다. 그 결과, 생육(Table 1)은 접수의 줄기 직경이 지중가온 처리시 10.22mm로, 무가온의 8.64mm보다 굵었고, 엽장과 엽폭에 있어서도 지중가온 처리가 무가온 처리보다 좋았다. 곡과 발생수에 있어서도 지중가온 처리는 주당 0.73개가 발생하였으나, 무가온은 1.26개가 발생되어 지중가온 처리시 무가온에 비해서 생육이 좋아지고, 곡과 발생이 적었다. 주당 측지발생수(Table 2)는 지중가온구가 13.7개였고, 무가온구는 11.7개로 지중가온을 하면 측지발생수가 증가함을 알수 있었다. 또한 상품수확과수에 있어서도 지중가온구는 주당 45개인데 반해 지중무가온구는 38개였으며 따라서 전체적인 수량이 10a당 8,100kg으로, 무가온구의 6,840kg보다 18%의 증수효과가 있었다. 따라서 수출오이재배시 지중가온을 하면, 측지발생수가 증가하고 특히 장측지(Fig. 1)가 다수 발생하여 측지 수확과수가 증가하며, 곡과 등 기형과 발생이 감소하여 상품수량이 증가되므로써 기존 지중 무가온 재배에 비해 14% 소득향상 효과를 기대할 수 있다.시 생장이 둔화되었다. 밀폐시킨 삼각플라스크에서 자라는 Cell은 상태도 좋지 않고 전반적인 증식량도 적었다. Cell은 환기정도에 민감한 것으로 판단되며 삼각플라스크에서 약 35일 정도의 생장 주기를 가지는 것으로 사료된다. 배양 3주까지는 플라스틱 뚜껑으로 밀폐시킨 bottle에서 가장 많은 체세포배를 얻었다. Air filter를 달아 2일 마다 신선한 공기를 넣어 주었을 때는 배의 발달이 많이 늦어져 배양 3주째에 다른 처리보다 배의 수가 훨씬 적었다. 체세포배가 발달하는 동안에는 산소를 많이 요구하지 않으나 성숙하는 동안에는 산소를 많이 요구하는 것으로 생각된다.적인 것으로 나타났다. 다만, 곡선형은 물론 직선형에서도 열교환 튜브의 배치밀도, 튜브 길이 및 두께 등의 변화에 따른 최적화 연구가 수반되어야 할 것으로 판단된다.에서 제공된 API는 객체기반 제작/편집 도구에 응용되어 다양한 멀티미디어 컨텐츠 제작에 사용되었다.x factorization (NMF), generative topographic mapping (GTM)의 구조와 학습 및 추론알고리즘을소개하고 이를 DNA칩 데이터 분석 평가 대회인 CAMDA-2000과 CAMDA-2001에서 사용된cancer diagnosis 문제와 gene-drug dependency analysis 문제에 적용한 결과를 살펴본다.0$\mu$M이 적당하며, 초기배발달을 유기할 때의 효과적인 cysteamine의 농도는 25~50$\mu$M인 것으로 판단된다.N)A(N)/N을 제시하였다(A(N)=N에 대한 A값). 위의 실험식을 사용하여 헝가리산 Zempleni 시료(15%$S_{XRD}$)의 기본입자분포로부터 %$S_{XRD}

• Journal of the Korean Institute of Landscape Architecture
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• v.40 no.5
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• pp.100-108
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• 2012

The purpose of the study was to evaluate the influence of shading and ventilation on Mean Radiant Temperature(MRT) of the outdoor space at a summer outdoor. The Wind Speed(WS), Air Temperature(AT) and Globe Temperature(GT) were recorded every minute from $1^{st}$ of May to the $30^{th}$ of September 2011 at a height of 1.2m above in four experimental plots with different shading and ventilating conditions, with a measuring system consisting of a vane type anemometer(Barini Design's BDTH), Resistance Temperature Detector(RTD, Pt-100), standard black globe(${\O}$ 150mm) and data acquisition systems(National Instrument's Labview and Compfile Techs' Moacon). To implement four different ventilating and shading conditions, three hexahedral steel frames, and one natural plot were established in the open grass field. Two of the steel frames had a dimension of $3m(W){\times}3m(L){\times}1.5m(H)$ and every vertical side covered with transparent polyethylene film to prevent lateral ventilation(Ventilation Blocking Plot: VP), and an additional shading curtain was applied on the top side of a frame(Shading and Ventilation Blocking Plot: SVP). The third was $1.5m(W){\times}1.5m(L){\times}1.5m(H)$, only the top side of which was covered by the shading curtain without the lateral film(Shading Plot: SP). The last plot was natural condition without any kind of shading and wind blocking material(Natural Open Plot: NP). Based on the 13,262 records of 44 sunny days, the time serial difference of AT and GT for 24 hour were analyzed and compared, and statistical analysis was done based on the 7,172 records of daytime period from 7 A.M. to 8 P.M., while the relation between the MRT and solar radiation and wind speed was analyzed based on the records of the hottest period from 11 A.M. to 4 P.M.. The major findings were as follows: 1. The peak AT was $40.8^{\circ}C$ at VP and $35.6^{\circ}C$ at SP showing the difference about $5^{\circ}C$, but the difference of average AT was very small within${\pm}1^{\circ}C$. 2. The difference of the peak GT was $12^{\circ}C$ showing $52.5^{\circ}C$ at VP and $40.6^{\circ}C$ at SP, while the gap of average GT between the two plots was $6^{\circ}C$. Comparing all four plots including NP and SVP, it can be said that the shading decrease $6^{\circ}C$ GT while the wind blocking increase $3^{\circ}C$ GT. 3. According to the calculated MRT, the shading has a cooling effect in reducing a maximum of $13^{\circ}C$ and average $9^{\circ}C$ MRT, while the wind blocking has heating effect of increasing average $3^{\circ}C$ MRT. In other words, the MRT of the shaded area with natural ventilation could be cooler than the wind blocking the sunny site to about $16^{\circ}C$ MRT maximum. 4. The regression and correlation tests showed that the shading is more important than the ventilation in reducing the MRT, while both of them do an important role in improving the outdoor thermal comfort. In summary, the results of this study showed that the shade is the first and the ventilation is the second important factor in terms of improving outdoor thermal comfort in summer daylight hours. Therefore, it can be apparently said that the more shade by the forest, shading trees etc., the more effective in conditioning the microclimate of an outdoor space reducing the useless or even harmful heat energy for human activities. Furthermore, the delicately designed wind corridor or outdoor ventilation system can improve even the thermal environment of urban area.

• Korean Journal of Optics and Photonics
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• v.20 no.5
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• pp.266-271
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• 2009

We designed a thermo-optic switch based on a directional coupler with not only a high extinction ratio but also significantly low power consumption. The switch operates by using the thermo-optic effect of the polymer which the refractive index changes by heating the electrode. If the electrode is not powered (OFF), the input light will be coupled completely to the other waveguide. When the electrode is powered at a certain level (ON), input light launched into the input waveguide will remain in that waveguide due to the lower index adjusted in the other waveguide. The switch based on the directional coupler was designed using the generalized extinction ratio curve and the lateral shift of the input waveguide. The coupling length is 1,610 ${\mu}m$ and the extinction ratios are -28 and -30 dB for ON and OFF states, respectively. The electrode structures were optimized by thermal analysis. The transported heat into the waveguide is increased, as the electrode width (w) is increased and the center distance between the electrode and the waveguide (d) is decreased. Also, because the heat generated in the electrode affects the other waveguide, the temperature difference between two waveguides is varied as the given w and d. There are specific conditions which have the maximum of the temperature difference. That of the temperature difference is increased as the width and the temperature of the electrode are increased. Especially, when the switch is designed using the condition with the maximum of the temperature difference for switching, the temperature of the electrode can be decreased. We expect this condition will be the novel method for the reduction of the power consumption in a thermo-optic switch.