• Journal of Astronomy and Space Sciences
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• v.13 no.2
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• pp.181-197
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• 1996

Thc CCD earth image experiment(CEIE) is one of the main payload of the KITSAT-1. Since it was launched on Age. 11, 1992, the CEIE has taken more than 500 images on the earth surface world-wide so far. An image from the space is very different from a feature on the real Earth surface due to various radiometric and geometric distortions. Preprocessing to remove those distortions has to take place before the image data are processed and analyzed further for various applications. This paper summarizes the result of the operation of the CEIE and describes the procedure to perform preprocessing including radiometric and geometric correction.

• Journal of Environmental Impact Assessment
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• v.7 no.2
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• pp.113-125
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• 1998

The amount of mercury emitted from an incinerator depends on the properties of waste, combustion condition, and control devices. Mercury concentration in air proportionates to the increase of incinerator installation. The purpose of this study is to provide a method for determination of mercury emission factor which can predict the amount of mercury emitted from each incinerator specifically. Case study was performed for N municipal waste incinerator. Based on the method presented in this paper, we obtained mercury emission factor as 1.85~1.95 g Hg/t at N Municipal Waste Incinerator and this result was regarded as reasonable when compared with existing mercury emission factor in reference cases. Fluorescent lamps turned out to be the most important source(44.4%) of mercury in municipal waste and its amount will tend to increase, while batteries become less significant. In addition, medical waste is one of the major source of mercury.

• Journal of Environmental Impact Assessment
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• v.11 no.2
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• pp.109-116
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• 2002

The diagnostic and prognostic methods for generating 3 dimensional wind field were comparatively analyzed and 4 dimensional data assimilation (FDDA) technique by incorporating Automatic Weather System (AWS) into the prognostic methods was discussed for the urban scale air quality model. The A WS covered the urban scale grid distance of 10.6 km and 4.3 km in South Korea and Kyong-in region, respectively. This is representing that AWS for FDDA could be fairly well accommodated in prognostic model with the meso${\gamma}$~ microa scale (~5 km), indicating that the 3 dimensional wind field by FDDA technique could be a useful interpretative tool in urban area for the atmospheric environmental impact assessment.

• Proceedings of the KSRS Conference
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• 2008.03a
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• pp.86-89
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• 2008

도시공간모델은 공간의 문제 또는 현상들을 보다 종합적, 합리적으로 파악하는데 중요하다. 본 연구에서는 수치지도와 도화원도로부터 저렴하고 수치지도 기반의 공간분석에 유용한 지형과 건물을 포함하는 도시공간모델을 생성하고자 한다. 도시공간모델은 지면모델과 건물모델로 나누어 생성한 후 통합한다. 지면모델은 수치지도를 이용하여 DEM을 생성한다. 건물모델은 수치지도와 도화원도를 융합하여 생성한다. 제안된 방법은 영등포구 전체를 포함하는 수치지도와 서로 다른 시기에 생성된 3 set의 도화원도에 적용하였다. 본 연구에서 생성된 도시공간모델은 수치지도를 기반으로 공간분석을 하는 응용분야에서 요구하는 입력 형태로 제공할 수 있으므로 유용하다. 따라서 본 연구에서 제안하는 도시공간모델의 생성 방법론은 더 많은 분야의 공간분석을 위해 활용될 것이다.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1999.11a
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• pp.193-199
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• 1999

In the 3-Dimensional contact of the smooth spheres, the effects of friction on the contact area and the distribution of contact pressure was studied numerically. The contact area and pressure distribution was evaluated for the only normal load and for the case of a normal load in the presence of a tangential traction. To do this work, the technique of simple discretization using the load . displacement relationship for a uniformly distributed load of a rectangular patch was used.

• Transactions of Materials Processing
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• v.4 no.4
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• pp.390-397
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• 1995

A simple kinematically admissible velocity field is proposed to determine the final-stage extrusion load and the average extruded length in the square-die forward extrusion of non-axisymmetric bars from circular billets. The proposed velocity field is applied to the square-die extrusion of trochoidal gear-shaped bars and rectangular-shaped bars. The profile function of a rectangle is approximated by using a Fourier series. Experiments have been carried out with hard solder billets at room temperature. The theoretical predictions of the extrusion load are in good agreements with the experimental results and there is generally reasonable agreements in average extruded length between theory and experiment.

• Transactions of Materials Processing
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• v.4 no.4
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• pp.322-334
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• 1995

This study presents development of an expert system for process and die design of hot extrusion through square dies. The design of extrusion dies is still an art rathere than a science with increasing complexity of shape and thinness of section. Therefore, most of the die design is still dependent on personal judgement, intuition and experience. The objective of this study is to develop an expert system which includes a rule base system extracted from literatures and experts in the extrusion industry. The system also includes finite element simulation program. The developed system is effectively used to design two types of processes and dies with lead time and trial extrusion.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1996.10a
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• pp.14-19
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• 1996

This study presents development of finite element simulation program and analysis of hot extrusion through square dies with mandrel. The design of extrusion dies is still an art rather than science. Die design for a new extrusion is developed from through in-plant trials. In the present paper, three-dimensional steady-state finite element simulation program is developed. The developed system is effectively used to simulate extrusion of clamp shaped hollow section. The objective of the present paper is to study the possibility of integrating this method into the design of dies for extrusion of complex section. To obtain sound product, the distributions and effects of temperature, effective strain rate, mean strain rate and mean stress are studied.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1996.03b
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• pp.138-144
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• 1996

In square die extrusion, flow guide and ide land play important roles for controlling the metal flow in die design. In the present work, the flow guide and the die land are considered for the die construction. Based on ALE description , rigid-viscoplastic finite element analysid is carried out to assess the effects of process and die design parameters. The thermal state affects greatly the product quality in hot extrusion. in the present work, the temperature distribution is also analyzed in theframwork of rigid-viscoplastic finite element computation. As a computational example, hot square die extrusion with flow guide and die land has been analyzed for the profile of a H section.

• Journal of Physiology & Pathology in Korean Medicine
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• v.24 no.1
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• pp.22-25
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• 2010

Hyangsapyeongwi-san has been used for various gastrointestinal diseases in Oriental medicine. Nevertheless, there is little known to scientific evidence for its efficacy and mechanism. This study was aimed to investigate effects of Hyangsapyeongwi-san in gastrointestinal diseases through the analysis of articles. A total of 15 articles were selected from PubMed, KTKP, and Weipu. The selected articles were analyzed according to three aspects of study types, target diseases and its efficacy, and results of clinical studies. Hyangsapyeongwi-san has positive effects in gastrointestinal disorders, such as prevent gastric mucosal injury, improve hyperacidity and dyspepsia, protect oxidative damage, and antitumor effects and enhance both cellular and humoral immunity. However, it proved insufficient to confirm its efficacy owing to lack of clinical studies of high quality. So, we need well designed studies to verify clinical efficacy of Hyangsapyeongwi-san hereafter.