• Title/Summary/Keyword: space plane

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Performance Analysis on Solar Tracking Daylighting Systems Using Different Types of Solar Collectors: Parabolic Dish vs. Fresnel Lens (태양추적식 자연채광 장치의 집광기 종류에 따른 성능 분석: 포물 반사경 vs. 프레넬 렌즈)

  • Kim, Yeongmin;Kim, Won-Sik;Jeong, Hae-Jun;Chun, Wongee
    • Journal of the Korean Solar Energy Society
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    • v.37 no.1
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    • pp.39-45
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    • 2017
  • This paper presents the effect of solar collectors on the performance of solar tracking daylighting systems. A series of measurements were made for two different types of solar collectors mounted on double axis solar trackers: Parabolic dish concentrator and Fresnel Lens. Indoor light levels were measured at different locations of an office space (longitude: 126.33 E, latitude 33.45 N) as photo sensors were placed on a task plane 80 cm above the floor. To accurately monitor the applicability of the systems, measurements were performed under clear and overcast sky conditions with the roll-screen (on the south window) in the down position. Comparing the illuminance data, the system with Fresnel lens outperformed that of parabolic dish concentrator. On clear days, the former delivered the light levels of 400~600 lux on the task plane whereas the latter recorded 100~200 lux. Depending on the amount of cloud cover, on overcast days, illuminance readings fluctuated to some extent.

AN EXPERIMENTAL STUDY ON THE EFFECT OF POSTERIOR DISPLACEMENT OF THE MANDIBLE ON THE TEMPOROMANDIBULAR JOINT IN RATS (백서 하악골의 후방 이동이 과두에 미치는 영향에 관한 실험적 연구)

  • Park, Kyung Jin
    • The korean journal of orthodontics
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    • v.10 no.1
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    • pp.29-36
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    • 1980
  • Inclined plane, one of frequently used orthodontic appliances, may cause posterior displacement of mandible and injure the normal growth of temporomandibular joint. So author carried out the mandibular posterior displacement experimentally induced by inserting inclined plane in the rat incisors in order to investigate the histological reactions occuring in the temporomandibular joint of experimental animals. Following results were obtained. 1. The posterior displacement of condyle resulted in the widening of anterior synovial space with anterior condylar hyperplasia and posterior condylar atrophy. In addition, tissue changes were more severe in young rats than in adult rats. 2. The tissue reactions were localized only to condylar head ana there were no evidence of traumatic features in young rats. In adult rats, hemorrhage was an additional finding 1 week after experiment. 3. The remodelling processes were accompanied by the increasing or reduction of fibrous layer and subsequent replacement by cartilage layer occured massively and abruptly in young rats, it occured slightly and slowly in adult rats. 4. The remodelling process of injured condyle occured from 1 week to 4 weeks after experiment and completed between 8 weeks after experiment.

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A Study on the Layout and Floor Plan of Hyangkyo Architecture at Youngseo districts in Gangwon-do (강원 영서지방 향교건축의 배치 및 평면특성에 관한 연구)

  • Rim, Sang-Kyu;Chai, Hee-Jai
    • Journal of the Korean Institute of Rural Architecture
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    • v.13 no.4
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    • pp.9-16
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    • 2011
  • This study aims to research the local characteristics of layout and floor plan at Hyangkyo Archiecture in Youngseo districts of Gangwon-do. Hyangkyo which were the institutional places of Chosun Dynasty used for stability and order of the dynasty as well as for the education of people. This thesis studies and analyzes the regularity which appears in the formation of architecture mainly in the aspects of layout, plane formality. Jeon-hak-hoo-myo is the arraying formality in which Myungryundang and Daesungjun are placed on a line of one axis with Myungryundang placed lower in the front and Daesungjun place higher in the back and this formality is applied for a land that slopes. The layout formation of Gangkak space is divided into Jeonjaehudang-type and Jeondanghujae-type. This study analyze arrangement type and plane characteristics about local old time school belonging to the Confucian shrine construction at Youngseo districts in Gangwon-do, there is purpose of research to wish to clear the regional special quality of local old time school belonging to the Confucian shrine construction at Youngseo districts in Gangwon-do.

A Study on the Feature of the Dimension Plan at Happy Village - Focused on the Comparative Traditional House in Chonnam Province - (전라남도 행복마을 가옥의 치수계획 특징에 관한 연구 -전라남도 전통가옥과의 비교를 중심으로-)

  • Sung, Dae-Chul;Shin, Woong-Ju
    • Journal of the Korean Institute of Rural Architecture
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    • v.14 no.4
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    • pp.135-142
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    • 2012
  • This study is aimed to investigate the dimension feature of the plane about the economic type farming village Korean-style house progressed in the Chonnam province and Longitudinal feature and tries to reveal this feature through the comparing analysis with the traditional house positioned in the Chonnam province. This result is as follows. First, the main feature in plane is the setting up the column interval in front when comparing the house of Happy Village and traditional house. In case house of the Happy Village, after firstly fixed the limited scales, sizes are determined, this is due to control the set up in the post interval in this in range. Second, in the case of the traditional houses, 0.68 ratio of the building height about the side length and 0.19 ratio of the eaves extrusion about the side length are consistent ratio about dimensions. However, there is no consistent ratio or fixed law, the various dimensions show up in case of the house of Happy Village. It will be inevitable that space of the post increases for the convenience of life of the modern people. However, it has to sublate and to disregard as the identity of the morphological shown up in the Korean-style house the more various construction standards will need to be presented.

Influence of ground motion spatial variations and local soil conditions on the seismic responses of buried segmented pipelines

  • Bi, Kaiming;Hao, Hong
    • Structural Engineering and Mechanics
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    • v.44 no.5
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    • pp.663-680
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    • 2012
  • Previous major earthquakes revealed that most damage of the buried segmented pipelines occurs at the joints of the pipelines. It has been proven that the differential motions between the pipe segments are one of the primary reasons that results in the damage (Zerva et al. 1986, O'Roueke and Liu 1999). This paper studies the combined influences of ground motion spatial variations and local soil conditions on the seismic responses of buried segmented pipelines. The heterogeneous soil deposits surrounding the pipelines are assumed resting on an elastic half-space (base rock). The spatially varying base rock motions are modelled by the filtered Tajimi-Kanai power spectral density function and an empirical coherency loss function. Local site amplification effect is derived based on the one-dimensional wave propagation theory by assuming the base rock motions consist of out-of-plane SH wave or combined in-plane P and SV waves propagating into the site with an assumed incident angle. The differential axial and lateral displacements between the pipeline segments are stochastically formulated in the frequency domain. The influences of ground motion spatial variations, local soil conditions, wave incident angle and stiffness of the joint are investigated in detail. Numerical results show that ground motion spatial variations and local soil conditions can significantly influence the differential displacements between the pipeline segments.

Block Deformation Analysis Using Three-dimensional Discontinuous Deformation Analysis(DDA) (삼차원 불연속 변형 해석(DDA)을 이용한 블록거동해석)

  • 장현익;이정인
    • Tunnel and Underground Space
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    • v.12 no.3
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    • pp.158-170
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    • 2002
  • Since the development of Discontinuous Deformation Analysis (DDA) by Shi (1984), there has been much improvement in the theory and programs. These, however, are all based on the assumption of a two-dimensional plane strain or plane stress state; and because a rock block system is a three-dimensional problem, a two-dimensional analysis has limited application. So a three-dimensional analysis is required in the design of rock slopes and underground spaces where three-dimensional discontinuities dominate stability. In this study three-dimensional DDA program is developed using the Shi's two-dimensional theory and program, and the two cases of three-dimensional block are analysed. The program is applied to one sliding-face blocks and wedge sliding and it gives the good results comparing to the exact solution. Multi-block cases will be analysed for many other application soon.

Lyα Radiative Transfer and The Wouthuysen-Field effect

  • Seon, Kwang-Il;Kim, Chang-Goo
    • The Bulletin of The Korean Astronomical Society
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    • v.42 no.2
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    • pp.43.1-43.1
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    • 2017
  • A three-dimensional (3D) Lyα radiative transfer code is developed to study the Wouthuysen-Field effect, which couples the 21 cm spin temperature of neutral hydrogen and the Lyα radiation field, and the escape fraction of Lyα from galaxies. The Monte Carlo code is capable of treating arbitrary 3D distributions of Lyα source, neutral hydrogen and dust densities, gas temperature, and velocity field. It is demonstrated that the resonance-line profile at the center approaches to the Boltzmann distribution with the gas temperature. A plane-parallel ISM model, which is appropriate for the neutral ISM of our Galaxy, is used to calculate the Lyα radiation field strength as a function of height above the galactic plane. We also use a two-phase, clumpy medium model which is composed of the cold and warm neutral media (WNM). It is found that the Lyα radiation field is strong enough to thermalize the 21 cm spin temperature in the WNM to the gas kinetic temperature. The escape fraction of Lyα is found to be a few percent, which is consistent with the Lyα observations of our Galaxy and external galaxies.

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THE STUDY OF SCATTERING IN THE ISM WITH HIGH RESOLUTION OBSERVATIONS OF OH MASERS

  • Migenes, Victor;Slysh, V.I.;Velasco, A.E.Ruis;Villalpando, S.
    • Journal of The Korean Astronomical Society
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    • v.40 no.4
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    • pp.131-132
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    • 2007
  • The research of OH maser emission sources with high angular resolution is complicated by the effects of interstellar scattering: more over, most of the OH maser sources are located in the galactic plane where the scattering is largest. However, the data available from pulsar studies on the spatial distribution of the amount of scattering indicate that there is a strong non-uniformity in the distribution of the amount of scattering material. There are directions in the galactic plane where the scattering is an order of magnitude higher than the average, as well as directions where the scattering is much lower. The latter provide an opportunity to investigate OH masers with the full angular resolution offered by very long baseline interferometry instruments, like the VLBA, and measure their true angular size, shape and brightness temperature. We have observed approximately 100 OH maser sources, distributed all over the northern hemisphere, with the VLBA in order to study the scattering properties of the interstellar medium.

Post Occupancy Evaluation of Hanok in Rural Area and Comparative Study on the Perception of Hanok -Hanok Residents and Architectural Designers Comparison Based on- (농촌한옥의 정주성 평가 및 한옥에 대한 인식도 비교 연구 -한옥거주자와 건축설계자간의 비교를 중심으로-)

  • Lee, Chang-Jae;Choi, Il
    • Journal of the Korean Institute of Rural Architecture
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    • v.12 no.2
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    • pp.77-84
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    • 2010
  • Hanok has been widely distributed as a support policy by local governments for the purpose of improving residential environment. In this study, Hanok in a rural area was founded was to evaluate the user's satisfaction. Hanok between residents and the perception of architects and tries to figure out the difference. Current Hanok residents showed higher satisfaction, but they showed negative response for high construct cost, plane form of building, insulation performance and noise. According to the comparison of recognition between residents and architectural designers, they showed differences in "Low soundproofing", "lack of storage space", "Equipment", "Tile", "The modularity of the flat panel design", and "The modularity of construction materials" and it was examined that architectural designers group had higher preference for traditional materials and forms. For succeeding to the traditional architectural factors of Hanok and distributing it as modern house, the research on use of modern materials and modulation of plane and members should be performed for reducing construction cost and improving insulation performance.

A Study on the Control Performance for Hazardous Gases by Surface Discharge induced Plasma Chemical Process (연면방전의 플라즈마 화학처리에 의한 유해가스제어 성능에 관한 연구)

  • 이주상;김신도;김광영;김종호
    • Journal of Korean Society for Atmospheric Environment
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    • v.11 no.2
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    • pp.185-190
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    • 1995
  • Recently, because of the worse of the air pollution, the excessive airtught of building and the inferiority of air conditioning system, the development of high efficiency air purification technology was enlarged to the environmental improvement of an indoor or a harmful working condition. The air purification technology has used chemical filters or charcoal filters or charcoal to remove hazardouse gaseous pollutants (SOx, NOx, NH3, etc.) by air pollutant control technology, but they have many problems of high pressure loss, short life, wide space possession, and treatment of secondary wastes. For these reason, the object of reasearch shall be hazardous gaseous pollutants removal by the surface discharge induced plasma chemical process that is A.C. discharge of multistreams applied A.C. voltage and frequency between plane induced eletrode and line discharge eletrode of tungsten, platinum or titanium with a high purified alumina sheet having a film-like plane. As a result, the control performance for hazardous gaseous pollutants showed very high efficiency in the normal temperature and pressure. Also, after comtact oxidation decomposition of harmful gaseous pollutants, the remainded ozone concentration was found much lower than that of ACGIH or air pollution criteria in Korea.rea.

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