• Title/Summary/Keyword: view factor

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Classification and Analysis of the Somatotype through Side View Silhouette of the whole body by Multivariate Method (다변량분석법에 의한 측면전신체형 분류)

  • 권숙희
    • Journal of the Korean Society of Clothing and Textiles
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    • v.21 no.7
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    • pp.1227-1235
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    • 1997
  • The purpose of this study was to classify the somatotype based on the side view and to analyze the characteristics of each somatotype. In order to reduce the burden of stocks and increase clothing fitness, systematic information on typical body sizes and somatotypes is essential. The subjects were 206 unmarried women aged from 19-29. Data were collected through anthropometry and photometry and analyzed by factor analysis, cluster analysis and analysis of variance. As the result of factor analysis for the classification of somatotypes, 8 factors which explain 74.7% of variance were extracted from 35 photometric and 17 anthrometric data. Using factor scores cluster analysis was carried out and the subjects were classified into 4 cluster.Each cluster was classified as bending type, swayback, turning over type and straight type accordding to its position to the relativeplumb line and their side view contour.

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A solution method of view factor by the area weighted average and graphical methods (면적가중 평균법과 그래프 해법에 의한 형태계수의 해석)

  • 유승호;손장열
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.11 no.6
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    • pp.709-715
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    • 1999
  • To optimize a heating and cooling system, we need an exact solution lot radiant heat transfer in any form of room or building. This paper describes the solution method of view factor by the area weighted average and graphical method to calculate the radiant heat exchange or daylighting level in any form of room or building. This study shows that the area weighted average and graphical methods have many points of merits(calculation speed, correctness and calculation capability in an arbitrary form of room shapes etc.) compared with existing methods

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Hemi-cube algorithm and its application to thermal analysis of crystal growth furnace (반정육면체 알고리즘 및 단결성 성장로의 열해석에의 응용)

  • Lee, Seung-Bok;Jeong, Jin-Su;Go, Sang, Geun
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.22 no.7
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    • pp.905-914
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    • 1998
  • View factor determination is very important in thermal analysis problems with surface radiation but it is very difficult to determine view factors for complex geometries. Exact calculation of view factors for crystal growth furnace is essential due to not only its high surface temperature but the radiation shield, complicated heating system. In this study, view factor calculation algorithm is introduced and applied to cylindrical crystal growth furnace. This algorithm is based on the Hemi-Cube Algorithm and the results obtained with this algorithm show good agreements with those of analytical solution. As an application of this algorithm, temperature profiles and heating value distributions for various furnaces are calculated and the shape criteria for better furnace are suggested.

Classification of Men's Somatotype According to Body Shape and Size(Part II) -Classification of Side View and Compound of Front and Side View- (남성의 동체부 체형분류(제2보) -측면체형의 분류 및 정면과 측면 체형의 조합-)

  • 정재은;김구자
    • Journal of the Korean Society of Clothing and Textiles
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    • v.26 no.10
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    • pp.1443-1454
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    • 2002
  • The purposes of this study were to classify body type of adult males into several kind of shape and to provide the characteristics of size of each group which has same shape. As the sample, subjects were 1290 males of 20 to 54 year-old. The procedure and results were follows; 1. As the result of the previous reserch, the front line of body was classified in X, H, Y and A types. 2. The principal component analysis was used to obtain the shape factor of the side line of the trunk. 9 factors in the side were extracted. As the result of the cluster analysis of factor scores, the side line of body was classified in 5 types. It was named X, A, Y and H type in the front and S, D1, d, I and D2 type in the side. 3. In order to consider the shape of body as a whole, the body shape of the front and side were compounded. The whole body shapes of adult male were very various, and 6 body shapes, XS, YS, Yd, YI, AD2 and HD1 were selected as the basic types. In each type of body, several groups were classified by size factor, height and chest girth and master size was selected considering appearance frequency.

Phenotypic Factor Analysis for Linear Type Traits in Beijing Holstein Cows

  • Chu, M.X.;Shi, S.K.
    • Asian-Australasian Journal of Animal Sciences
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    • v.15 no.11
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    • pp.1527-1530
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    • 2002
  • Factor analysis was applied to the phenotypic correlation matrix of 15 linear type traits (scored linearly 1 to 50 points) for 2035 Holstein cows of 38 sires computed from data collected between 1988 and 1992 in Beijing Shuangqiao Farm and Beijing Xijiao Farm. The 15 linear type traits were stature, body strength, body depth, dairy form, rump angle, rump length, rump width, rear leg side view, foot angle, fore udder attachment, rear udder height, rear udder width, udder cleft, udder depth and teat placement rear view. The first four components accounted for 49.1% of the total variance in type scores. Factor 1 reflected strong cows, with deep bodies, with long and wide rumps, and tall in stature. Factor 2 reflected cows with well attached fore udders, wide rear udders and whose udders were supported by strong suspensory ligaments with close teat placement. Factor 3 reflected cows with good dairyness, sickled in the hocks, high rear udders and udder floors above the hocks. Factor 4 reflected cows with sloping rumps from hooks to pins and with steep foot angle. Principal component and factor analyses are useful to clarify the relationships among type traits.

A Comparative Analysis of Field and Slide Survey on Subjective Image of the Nightscape (야경의 주관적 이미지에 관한 현지평가와 슬라이드평가의 비교분석)

  • Ahn, Hyun Tae;Moon, Ki Hoon;Kim, Jeong Tai
    • KIEAE Journal
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    • v.7 no.2
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    • pp.31-37
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    • 2007
  • Despite of many supportive research to the usefulness of slide evaluation on environment of outdoor lighting, study method of using slides have provoked many discussions of its manifestation of reality of field conditions. This study aims to compare the results of slide survey with that of field survey. Distant view and short range view of nightscape of Seoul were selected. Field measurement of luminance and chromaticity were conducted and questionnaire survey were conducted. Frequency analysis, T-test, factor analysis were conducted. Results shows that distant view and short range view of field survey have better visual atmosphere than slide survey. In addition, slide survey on distant view shows lowest values. Difference between field survey and slide survey on distant view is much bigger than the results of short range view.

STUDY ON VIEW FACTOR CALCULATION FOR RADIATIVE HEAT TRANSFER BY USING THE MESH SUBDIVISION METHOD (격자 세분화 방법을 고려한 복사열전달 형상계수 계산 기법 연구)

  • Kim, D.G.;Han, K.I.;Choi, J.H.;Lee, J.J.;Kim, T.K.
    • Journal of computational fluids engineering
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    • v.19 no.1
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    • pp.1-6
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    • 2014
  • Since experiments on the actual operational status are said to be very impractical because of their economic and repeatability problems, it is difficult to understand the thermal profiles of aerospace or military equipments. Thus, the CFD codes with considering the radiation heat transfer are used to compensate the defect. In case, analyzing the radiation exchanges between the object surfaces are very important. Because the temperature and the IR signal distributions of the object surface are significantly affected by the radiative heat transfer. To achieve accurate thermal radiation exchange between surfaces, it is important to calculate the radiation view factor precisely. Finer subdivision of meshes can be used to increase the accuracy of radiation view factor, but if the mesh is subdivided infinitely, the time required for calculation increases significantly and thus decreasing the efficiency. If the subdivision is not sufficient, assurance of accuracy is not guaranteed. In this paper, optimal mesh subdivision method using the solid angle has been successfully tested and found to be useful in increasing the efficiency of calculating the shape factors.

Visible Project Area for Korean Child (Six Years Old) in Radiant Enclosures (한국 어린이를 위한 복사 공간에서의 투사 면적에 관한 연구)

  • 손철수;최민권
    • Journal of the Korean housing association
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    • v.11 no.4
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    • pp.77-84
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    • 2000
  • The purpose of this paper is to find a visible project area for an average six year old Korean child in radiant enclosures having standing pose. The results using this method will be necessary to find effective radiation area, effective radiation area factor, form factor, and mean radiant temperature for an average six years old Korean child consists of 3012 triangles. The methods to find visible project area of an average six years old Korean at arbitrary view point will be presented. The visible project area for Korean child is needed for evaluating thermal comfort for six years old Korean child. The biggest visible project area of an average six years old Korean is $\textrm{cm}^2$$2.061.0\textrm{cm}^2$ at the view point of alfa 0.0 degree and beta 0.0 degree, and the smallest visible real area of an average six years old Korean is $567.1\textrm{cm}^2$ at the view point of alfa 15.0 degree and beta 90.0 degree.

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Classification of Men's Somatotype According to Body Shape and Size(Part I) -Classification of Front View According to Body Shape- (남성의 동체부 체형 분류(제l보) - 인체의 형태에 의한 정면 체형의 분류 -)

  • 정재은;이순원
    • Journal of the Korean Society of Clothing and Textiles
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    • v.26 no.7
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    • pp.1026-1035
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    • 2002
  • The purposes of this study were to classify the front view of trunk of adult males into several kinds of shape and to provide the characteristics and silhouette of each group which has same shape. As the sample, subjects were l290 males of 20 to 54 year-old. The procedure and results were follows; l. The principal component analysis was used to obtain the shape factor of the front of the trunk 8 factors in the front which explained 86.8% of total variance were extracted. 2. As the result of the cluster analysis of factor scores, the font of body was classified in 4 types. 4 types were named X, A, Y and H type in the front considering the characteristics of each type.

A NUMERICAL METHOD TO ANALYZE GEOMETRIC FACTORS OF A SPACE PARTICLE DETECTOR RELATIVE TO OMNIDIRECTIONAL PROTON AND ELECTRON FLUXES

  • Pak, Sungmin;Shin, Yuchul;Woo, Ju;Seon, Jongho
    • Journal of The Korean Astronomical Society
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    • v.51 no.4
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    • pp.111-117
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    • 2018
  • A numerical method is proposed to calculate the response of detectors measuring particle energies from incident isotropic fluxes of electrons and positive ions. The isotropic flux is generated by injecting particles moving radially inward on a hypothetical, spherical surface encompassing the detectors. A geometric projection of the field-of-view from the detectors onto the spherical surface allows for the identification of initial positions and momenta corresponding to the clear field-of-view of the detectors. The contamination of detector responses by particles penetrating through, or scattering off, the structure is also similarly identified by tracing the initial positions and momenta of the detected particles. The relative contribution from the contaminating particles is calculated using GEANT4 to obtain the geometric factor of the instrument as a function of the energy. This calculation clearly shows that the geometric factor is a strong function of incident particle energies. The current investigation provides a simple and decisive method to analyze the instrument geometric factor, which is a complicated function of contributions from the anticipated field-of-view particles, together with penetrating or scattered particles.