• Title/Summary/Keyword: boundary characteristics

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A Study on the Classification of Lower Body Shape Type for Fit Evaluation of Slacks (슬랙스 맞음새 평가를 위한 하반신 체형 유형화에 관한 연구)

  • Kim, Seonyoung;Nam, Yunja
    • Journal of Fashion Business
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    • v.20 no.2
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    • pp.181-196
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    • 2016
  • This study intended to suggest criteria for selection of subjects by lower body shape types necessary for evaluating slacks. For this, the characteristics were examined by lower body parts which would influence the fit of slacks on 3D human body shape data of the front and sides of the lower body for lower body shaping. The frequency of subjects by lower body shape types and the boundary points for discrimination of each type were suggested so that they could be available in selecting subjects. Using the data from Size Korea(2004), indirect measurement values measured on the front and sides of the lower body among 3D human body shape data of 175 subjects were analyzed. Their height, waist, and hip circumference fell under the range of standard deviation based on the mean of women aged 18~24 years, and then lower body shaping was conducted by combining the front and side shapes of the lower body. The front of the lower body was classified into four sections: average waist/average hip type(F1), average waist/narrow hip tyle(F2), narrow waist/narrow hip type(F3) and narrow waist/wide hip type(F4) and the sides of the lower body were divided into four sections: average abdomen/average hip type(S1), flat abdomen/average hip type(S2), average abdomen/protrude hip type(S3)and round abdomen/flat hip type(S4), and thus total 16 lower body types were created by cross analysis. Besides, discriminant analysis suggested the boundary points for each shape type of the front and sides of the lower body as a criterion for deciding lower body shape type of each subject

Geotechnical Characteristics of Frost-Susceptibility Soil Using Modified Freeze-Thaw Apparatus (변형된 동결-융해 시험장치를 이용한 동상민감성흙의 지반공학적 특성)

  • Shin, Eun-Chul;Ryu, Byung-Hyun;Park, Jeong-Jun
    • Journal of the Korean Geosynthetics Society
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    • v.8 no.1
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    • pp.53-59
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    • 2009
  • A new system of modified freeze-thaw testing apparatus is introduced. This system is developed to evaluate the geotechnical parameters and their dependence upon freezing-thawing history of frost-susceptibility soil. A necessary condition for stationary frost heaving is clarified in this paper. The method changes the thermal boundary condition up to the net heat flow at the freezing frost becomes zero. The effectiveness of this method is verified by freeze-thaw tests. Frost heaving observed after the application of the method is found to be due to another frost heaving action called long-term frost heaving. This frost heaving has already been studied and is considered ignorable as engineering factor because of its small heaving amount.

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Inundation Analysis on the Region of Lower Elevation of a New Port by Using SWMM5 and UNET Model - Yongwon-dong, Jinhae-si (SWMM5와 UNET 모형을 이용한 신항만 저지대 침수분석 - 진해시 용원동)

  • Lee, Jung-Min;Lee, Sang-Ho;Kang, Tae-Uk
    • Journal of Korean Society on Water Environment
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    • v.24 no.4
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    • pp.442-451
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    • 2008
  • We analyzed characteristics of rainfall-runoff for the channel of Yongwon area made by a new port construction. And we conducted inundation analysis on the region of lower elevation near the coast. SWMM5 was calibrated with the storm produced by the typhoon Megi from August 19 to August 20 in 2004, and was verified with the storm from August 22 to August 22 in 2004. We performed hydraulic channel routing of Yongwon channel about typhoon Megi from August 19 to August 20 in 2004 by UNET model which is a hydraulic channel routing. The simulated runoff hydrographs were added to the new stream as lateral inflow hydrographs and a watershed runoff hydrograph was the upstream boundary condition. The downstream boundary condition data were estimated by the measured stage hydrographs. The maximum stage that was calculated by hydraulic channel routing was higher than the levee of inundated region in typhoon Megi. Thus we can suppose an inundation to have been occurred. We performed inundation analysis about typhoon Megi from August 19 to August 20 in 2004 and flood discharge of return period 10~150 years. And we estimated each inundation area. The inundation areas by return periods of storms were estimated by 3.4~5.7 ha. The causes of inundation are low heights of levee crests (D.L. 2.033~2.583 m), storm surges induced by typhoons and reverse flow through the coastal sewers (D.L. -0.217~0.783 m). A result of this study can apply to establish countermeasure of a flood disaster in Yongwon.

The Synoptic Characteristics of Heavy Rain in South Korea (한반도 집중호우의 종관적 특성)

  • Jeong, Goan-Young;Ryu, Chan-Su
    • Journal of Integrative Natural Science
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    • v.1 no.2
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    • pp.89-114
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    • 2008
  • Interrelationship between heavy rainfalls and related with low-level jets(LLJ) is analyzed by using fifty cases of heavy rainfall events occurred over the Korean peninsula from 1992 to 2001. Those cases are classified with four synoptical features. There are 32% chances that the low pressure exist in heavy rainfall over than 150 mm per day case by case. Secondly Changma front and front zone account for 28% of all cases. The ratio of marine tropical boundary type and trough type record 22% and 18% respectively. The moist and warm south-westerly winds associated with low-level jets have been induced convective instability and baroclinic instability. Therefore, heavy rainfall due to the approach of a low pressure occurred at September and before Changma. During the period of Changma, this type has been happened heavy rainfall when low pressure and stationary front has vibrated south and north. Changma type has longer the duration time of precipitation than other types. Third type, located with marine Tropical boundary, have mainly rained in August and September. The last trough case locally downpoured in short time with developing cell. The occurrence low-level jets related to heavy rainfall has increased over 12.5 m/s wind speed. The result is that 43 heavy rainfalls out of 50 cases reach peak at the time of maximum precipitation intensity. Also, the variation of wet number and K-index corresponded with the variation of wind speed. It is found that the number of frequency of low-level jets with southwestward direction has been increased and these jets are mainly passed from the southwest toward to the northeast of the Korean peninsula in that time.

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Wave-Induced Soil Response around Submarine Pipeline (파랑작용에 의한 해저파이프라인 주변지반의 응답특성)

  • Hur, Dong-Soo;Kim, Chang-Hoon;Kim, Do-Sam
    • Journal of Ocean Engineering and Technology
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    • v.21 no.1 s.74
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    • pp.31-39
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    • 2007
  • Recently, the nonlinear dynamic responses among waves, submarine pipeline and seabed have become a target of analyses for marine geotechnical and coastal engineers. Specifically, the velocity field around the submarine pipeline and the wave-induced responses of soil, such as stress and strain inside seabed, have been recognized as dominant factors in discussing the stability of submarine pipeline. The aim of this paper is to investigate nonlinear dynamic responses of soil in seabed, around submarine pipeline, under wave loading. In order to examine wave-induced soil responses, first, the calculation is conducted in the whole domain, including wave field and the seabed, using the VOF-FDM method. Then, velocities and pressures, which are obtained on the boundary between the wave field and the seabed, are used as the boundary condition to compute the wave-induced stress and strain inside seabed, using the poro-elastic FEM model, which is based on the approximation of the Biot's equations. Based on the numerical results, the characteristics of wave-induced soil responses around submarine pipeline are investigated, in detail, inrelation to relative separate distance of the submarine pipeline from seabed. Also, the velocity field around the submarine pipeline is discussed.

A Study on the Container Yard of Mega-Float Offshore Structure Type. (부유체식 Container Yard에 관한 연구)

  • Park, Sung-Hyeon;Park, Sok-Chu;Ko, Jae-Yong
    • Journal of Navigation and Port Research
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    • v.27 no.1
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    • pp.49-54
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    • 2003
  • Recently, mega-float offshore structure is studied as of the effective utilization of the ocean space. And mega-float structure are now being considered for various applications such as floating airports. container yard, offshore cities and so on. This mega-float structure is relatively flexible compared with floating structures like large ship. When we estimate dynamic responses of these structures in waves, the elastic deformation is important, because vertical dimension is small compare with horizontal. the analysis of the dynamic reponses as it receive regular wave is studied. The finite element method is used in the analysis of structural section of this model. And the analysis is carried out using the boundary element method in the fluid division. In oder to know the characteristics of the dynamic response of the mega-float structures, effects of wavelength, water depth, and wave direction on the dynamic response of the floating structure are studied by use of numerical calculation.

Comparative Analysis on Interior Spaces of the Selected Historical Residences in the Western and Eastern Countries - focusing on case residences of Korea, China, Japan, Rome, Egypt, and Italy - (동서양 전통적인 주택 양식의 실내공간 특성 비교분석 연구 - 한국, 중국, 일본, 로마, 이집트, 이태리의 사례주택을 중심으로-)

  • 김연정;이연숙
    • Korean Institute of Interior Design Journal
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    • no.27
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    • pp.152-161
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    • 2001
  • At the multi-cultural society, research is needed to encourage a social atmosphere for enhanced understanding and respect for different cultures & countries. The purpose was to analyze the characteristics of spatial arrangement, space connection, Interior decoration and the relationship among these three features, which showed each country's unique housing form tradition. Three representative cases of historic residences from each country were selected on the basis of a recognized historic architecture directory. Total 18 residences from 6 countries - Korea, China, Japan, Rome, Egypt, and Italy - were comparatively analyzed. As results, aspects generally found in Eastern countries, were the fence as the semi-open boundary between the inside and the outside of the house, the flexibility of spatial opening and partitions between rooms, and finally simple and movable decoration features. On the other hands, aspects appeared in Western countries, were the outer wall of the building as the boundary to the outside, the closed and fixed properties of the room partitions, and finally complex and fixed decoration features. The research also showed that even within the same culture, the degree of openness varied. Each feature of space was related and could be explained within the same context. Housing, regardless of country and culture, tried to accommodate the exterior space inside the building as much as possible. The common pursuit was transformed to various visible forms and its reason might be due to different socio-cultural and environmental backgrounds that need to be continuously explored in academic area.

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Experimental and Numerical Analysis for Effects of Two Inclined Baffles on Heat Transfer Augmentation in a Rectangular Duct (사각 덕트 내에 설치된 2개의 경사진 배플에 의한 열전달 증진 효과에 관한 실험 수치해석)

  • Kang, Ho-Keun;Ahn, Soo-Whan;Putra, Ary Bachtiar Krishna
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.19 no.11
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    • pp.751-760
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    • 2007
  • Baffles enhance heat transfer by disturbing boundary layer and bulk flow, creating impingement, and increasing heat transfer surface area. This study was performed to determine how the two inclined baffles (${\alpha}=5^{\circ}$ perforated models) placed at a rectangular channel affect heat transfer and associated friction characteristics. The parametric effects of perforated baffles (3, 6 and 12 holes) and flow Reynolds number ranging from 28,900 to 61,800 on the heated target surface are explored. Comparisons of the experimental data with the numerical results by commercial code CFX 10.0 are presented. As for the investigation of heat transfer behaviors on local Nusselt number with two baffles placed at $x/D_h=0.8$ and $x/D_h=8.0$ of the edge of baffles, it is evident that the inclined perforated baffles augment overall heat transfer significantly by both jet impingement and boundary layer separation. There exists an optimum perforation density to maximize heat transfer coefficients; i.e., the average Nusselt number increases with increasing number of holes, but the friction factor decreases with an increase in the hole number placed at baffles.

Computing turbulent far-wake development behind a wind turbine with and without swirl

  • Hu, Yingying;Parameswaran, Siva;Tan, Jiannan;Dharmarathne, Suranga;Marathe, Neha;Chen, Zixi;Grife, Ronald;Swift, Andrew
    • Wind and Structures
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    • v.15 no.1
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    • pp.17-26
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    • 2012
  • Modeling swirling wakes is of considerable interest to wind farm designers. The present work is an attempt to develop a computational tool to understand free, far-wake development behind a single rotating wind turbine. Besides the standard momentum and continuity equations from the boundary layer theory in two dimensions, an additional equation for the conservation of angular momentum is introduced to study axisymmetric swirl effects on wake growth. Turbulence is simulated with two options: the standard ${\kappa}-{\varepsilon}$ model and the Reynolds Stress transport model. A finite volume method is used to discretize the governing equations for mean flow and turbulence quantities. A marching algorithm of expanding grids is employed to enclose the growing far-wake and to solve the equations implicitly at every axial step. Axisymmetric far-wakes with/without swirl are studied at different Reynolds numbers and swirl numbers. Wake characteristics such as wake width, half radius, velocity profiles and pressure profiles are computed. Compared with the results obtained under similar flow conditions using the computational software, FLUENT, this far-wake model shows simplicity with acceptable accuracy, covering large wake regions in far-wake study.

Boundary Detection using Adaptive Bayesian Approach to Image Segmentation (적응적 베이즈 영상분할을 이용한 경계추출)

  • Kim Kee Tae;Choi Yoon Su;Kim Gi Hong
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.22 no.3
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    • pp.303-309
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    • 2004
  • In this paper, an adaptive Bayesian approach to image segmentation was developed for boundary detection. Both image intensities and texture information were used for obtaining better quality of the image segmentation by using the C programming language. Fuzzy c-mean clustering was applied fer the conditional probability density function, and Gibbs random field model was used for the prior probability density function. To simply test the algorithm, a synthetic image (256$\times$256) with a set of low gray values (50, 100, 150 and 200) was created and normalized between 0 and 1 n double precision. Results have been presented that demonstrate the effectiveness of the algorithm in segmenting the synthetic image, resulting in more than 99% accuracy when noise characteristics are correctly modeled. The algorithm was applied to the Antarctic mosaic that was generated using 1963 Declassified Intelligence Satellite Photographs. The accuracy of the resulting vector map was estimated about 300-m.