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GENERATION OF DEM FROM CONTOURS FOR THE ORTHORECTIFICATION OF HIGH-RESOLUTION STELLITE IMAGES

  • Choi, Joon-Soo;Cha, Young-Min;Heo, Jae-Wee;Ryu, Young-Soo;Kim, Choen;Oh, Seung-Jun
    • Proceedings of the KSRS Conference
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    • 2008.10a
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    • pp.7-10
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    • 2008
  • We present a technique for constructing a digital elevation model (DEM) from contours. The elevation of each ground point in DEM is computed by interpolating the heights of the two adjacent contours of the point. The technique decomposes each sub-domain between adjacent contours into a set of sub-regions. The decomposition is accomplished by constructing a medial axis of the sub-domain. Each sub-region in the decomposition is classified into a variety of terrain features like hillsides, valleys, ridges, etc. The elevations of points are interpolated with different methods according to terrain features they belong to. For a given point in hillside, an approximate gradient line passing through the point is determined and the elevation of the point is interpolated from the known elevations of the two adjacent contours along the approximate gradient line. The univariate monotone rational Hermite spline is used for the interpolation. The DEM constructed by the technique is to be used to orthorectify the high-resolution KOMPSAT3 imagery.

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Quantitative Analysis of Anthraquinone and Stilbene Derivatives in Various Rhubarbs (대황류 생약의 인트라퀴논 및 스틸벤 유도체 함량분석)

  • Ko, Sung-Kwon;Han, Sung-Tai;Yang, Byung-Wook;Shin, Cha-Gyun;Hahm, Young-Tae;Cho, Soon-Hyun;Whang, Wan-Kyun
    • Korean Journal of Pharmacognosy
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    • v.36 no.4 s.143
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    • pp.257-262
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    • 2005
  • This study was carried out to obtain the basic information that can be used to index rhubarbs in six regions of China and Korea. The anthraquinone and stilbene contest in various rhubarb produced in th different area were quantitatively analysed by HPLC. The average of sennoside A content of the Chinghai rhubarb was higher than that of the other palmata rhubarbs(high-quality rhubarbs) produced in China. As a result, the order of the sennoside A content was 1) Chinghai rhubarb, 2) Tsuchan rhubarb, 3)Kansu rhubarb 4) Neimenggu rhubarb. On the other hand, the total stilbenes content of each of the cultivated Korean rhubarb(Rheum undulatum) were higher than that of the Chinese rhapontica rhubarb(low-quality rhubarbs).

Physical Properties of Human Hair by the Bleach (탈색시술 조건에 따른 모발의 물성변화)

  • Yun, Jong-Hyun;Kim, Ho-Jung;Lee, Young-Joo;Park, Cha-Cheol
    • Fashion & Textile Research Journal
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    • v.7 no.1
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    • pp.96-100
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    • 2005
  • The bleaching is one of the worst factors which leads to the damage of the human hair. The cuticle of the human hair is injured by the alkali that is one of the chief ingredients of a bleaching agent. The alkali component of the bleaching solution chemically reacts with human hair, reducing the tenacity and dissolving the cuticle layer. The purpose of this study is to examine the effects of bleaching time and temperature on the physical properties and morphology. The results were as follows. 1. The stress-strain curves for human hair indicated the three distinct regions, such as Hookean region, Yield region and post-Yield region. The tenacity of hair is reduced gradually with an increase of bleaching time. Under these same conditions, elongation of the hair increased. 2. The greatest drop in tenacity for hair occured between $40^{\circ}C$ and $60^{\circ}C$ of bleaching temperature. 3. Compared with the virgin hair, bleached hair showed a slower rate of weight reduction in the TGA thermogram. The rate decreased gradually as the bleaching time and temperature increased. 4. As the bleaching conditions reached time and temperature extremes, the human hair cuticle became more damaged. The cuticle layers seemed to have dissolved, as seen in the SEM photographs.

Analysis of Regional Food Specialities Status in Korea during the Japanese colonial period through 『Specialities of Joseon (朝鮮の特産)』 (『조선(朝鮮)の특산(特産)』으로 보는 일제강점기 식품 특산물 현황 분석)

  • Cha, Gyung-Hee
    • Journal of the Korean Society of Food Culture
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    • v.34 no.6
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    • pp.651-670
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    • 2019
  • This study examined the status of food specialties in Korea during the Japanese colonial period through 『Specialities of Joseon (朝鮮の特産)』. The book recorded a total of 164 areas and 317 specialties, focusing on five railway lines and branch lines on the Gyeongbu, Honam, Gyeongui, Gyeongwon, and Hamgyeong. Among the specialities, 211 species were included, excluding overlapping ones. The food specialties accounted for 100 kinds in 159 regions or 47.4 percent of the specialties. There were 47 food specialties in 47 areas of the Gyeongbu Line, 21 food specialties in 20 areas of the Honam Line, 32 food specialties in 40 areas of the Gyeongui Line, 26 food specialties in 15 areas of the Gyeongwon Line, and 33 food specialties in 42 areas of the Hamgyeong Line. Among the specialties, the amount of fish and their workpiece was overwhelmingly the largest. Next came processed goods of fruits, grains, and vegetables. In modern factories, corn, tomatoes, blueberries, and sardines were made of processed goods. Factories have been constructed for glass noodles, sugar, and soju. Specialities and processed goods produced in each region were brought to Japan during the Japanese colonial period.

Determination of Forest Road Construction Priority Order Using Multiple Criteria Decision Making Methods (다기준의사결정법(多基準意思決定法)에 의한 임도개설순위(林道開設順位)의 결정(決定))

  • Cha, Du Song;Cho, Koo Hyun;Kim, Jong Yoon
    • Journal of Korean Society of Forest Science
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    • v.85 no.2
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    • pp.149-157
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    • 1996
  • The applications of multiple criteria decision making(MCDM) methods were investigated to determine the priority order in forest road construction for timber harvesting and silvicultrual activities in 22 regions. In this paper, MCDM methods have five methods from two kinds of models. The one is non-compensatory preference model including maximin and maximax method; the other is compensatory preference model including simple additive weighting method(SAW), hierarchical additive weighting method(HAW) and technique for order preference by similarity to ideal solution(TOPSIS), SAW and TOPSIS methods turned out to be the most adequate for forest road construction priority order among the five methods tested in this study.

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Numerical Investigation on Aerodynamic Performance of a Centrifugal Fan with Splitter Blades

  • Kim, Jin-Hyuk;Cha, Kyung-Hun;Kim, Kwang-Yong;Jang, Choon-Man
    • International Journal of Fluid Machinery and Systems
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    • v.5 no.4
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    • pp.168-173
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    • 2012
  • This paper presents a numerical investigation on the aerodynamic performance according to the application of splitter blades in an impeller of a centrifugal fan used for a refuse collection system. Numerical analysis of a centrifugal fan was carried out by solving three-dimensional Reynolds-averaged Navier-Stokes equations with the shear stress transport turbulence model. A validation of numerical results was conducted by comparison with experimental data for the pressure and efficiency. From analyses of the internal flow field of the reference fan, the losses by the reverse-flows were observed in the region of the blade passage. In order to reduce these losses and enhance fan performance, two splitter blades were applied evenly between the main blades, and centrifugal impellers having the different numbers of the main blades were tested with their application. Throughout the numerical analyses of the centrifugal fan with splitter blades, it was found that the reverse-flow regions in the blade passage can be reduced by controlling the main blade numbers with splitter blades. The application of splitter blades in a centrifugal fan leads to significant improvement in the overall fan performance.

An Experimental Study of Heat Transfer Characteristics on the Electronic Module Arrangement (전자모듈의 배열에 따른 열전달특성의 실험적 연구)

  • Lee, Dae-Hee;Lee, Dae-Keun;Cha, Yoon-Seok;Lee, Jun-Sik
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.32 no.6
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    • pp.407-412
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    • 2008
  • Heat transfer from three-dimensional heat-generating modules was investigated. Simulated electronic module in an array configured with dummy module elements were used to measure the average heat transfer coefficients. Various module arrangements were tested using module spacings of 0.85 and 1.15 cm for six Reynolds numbers ranging from 500 to 975. The results show that a module placed in-line with and upstream of a heated module results in the heat transfer enhancement due to high turbulence intensity prompted by upstream modules. The highest enhancement occurs when the separation distance between modules is close to the module length in the flow direction. The laminar flow was observed on the front of the first module, slow recirculation regions on the sides parallel to the airstream, and turbulent flow on the back side. It appears that the first module serves to trip the air stream and produce a high level of turbulence, which enhances the heat transfer rate downstream.

Vulnerability assessment of upland public groundwater wells against climate change

  • Shin, Hyung Jin;Lee, Jae Young;Jo, Sung Mun;Cha, Sang Sun;Park, Chan Gi
    • Korean Journal of Agricultural Science
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    • v.47 no.3
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    • pp.577-596
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    • 2020
  • Drought is a natural disaster that directly affects agriculture, which has a great impact on the global agricultural production system and yield. The lack of water storage in most parts of the country due to the lack of precipitation has caused a great increase in social interest in drought due to the dryness of rice fields and crops. As the drought period increases and the drought intensity becomes stronger, it is believed that drought damage to crops will continue; thus, it is necessary to understand the vulnerability to irrigation performance and the ability of irrigation facilities. Therefore, this study conducted a vulnerability assessment of irrigation facilities (public Groundwater well) in cities across the country. The survey was conducted using statistical data from 2007 to 2016, and the vulnerability score was calculated according to the vulnerability evaluation procedure for drought in the irrigation facilities (public groundwater wells). Among 157 regions, 136 areas were very vulnerable; 14 areas were vulnerable; 3 areas were normal; 4 areas were good, and 0 areas were excellent. The vulnerability assessment can be used as basic data for the development or maintenance of field irrigation facilities in the future by understanding the vulnerability of irrigation facilities.

Simulation of Changes in Nearby Thermal Environment According to Green Roof in Low-Rise Residential Area of Daegu (대구광역시 저층주거지역의 옥상녹화 조성에 따른 주변 열환경 변화 모의실험)

  • Kim, Dae-Wuk;Jung, Eung-Ho;Cha, Jae-Gyu
    • Journal of the Korean housing association
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    • v.24 no.3
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    • pp.45-53
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    • 2013
  • It is important to secure green spaces to solve the urban heat island phenomenon, which is among problems resulted by high-density developments in metropolitan areas. However, it is hard to secure such green spaces in established urban areas so Green Rooftop development approaches have recently been highlighted and introduced as a solution to the situation. The present study conducts a simulation on residential areas in urbanized regions to quantitatively evaluate the effects of green rooftop developments through a comparison of changes in the air temperatures before and after relevant development projects. According to the evaluation results, when the green roof top development is conducted in the available areas, the temperature is reduced by 0.14 degree. The extension of green project to the entire building showed the reduction of the temperature by 0.29 degree. Based on these results, it can be concluded that the green rooftop development is a practically solution for reducing the air temperature of urbanized areas.

A Study on Korean Printed Character Type Classification And Nonlinear Grapheme Segmentation (한글 인쇄체 문자의 형식 분류 및 비선형적 자소 분리에 관한 연구)

  • Park Yong-Min;Kim Do-Hyeon;Cha Eui-Young
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2006.05a
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    • pp.784-787
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    • 2006
  • In this paper, we propose a method for nonlinear grapheme segmentation in Korean printed character type classification. The characters are subdivided into six types based on character type information. The feature vector is consist of mesh features, vertical projection features and horizontal projection features which are extracted from gray-level images. We classify characters into 6 types using Back propagation. Character segmentation regions are determined based on character type information. Then, an optimal nonlinear grapheme segmentation path is found using multi-stage graph search algorithm. As the result, a proposed methodology is proper to classify character type and to find nonlinear char segmentation paths.

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