• Title/Summary/Keyword: Three dimensional body

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Three-Dimensional Computations of Rocket Exhaust Plume (로켓 배기플룸에 관한 3차원 수치해석)

  • Kim Y.-M.
    • 한국전산유체공학회:학술대회논문집
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    • 1999.11a
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    • pp.71-76
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    • 1999
  • The base flow regions of a three-body sounding rocket containing multiple exhaust plumes were numerically investigated in three dimensions for a free stream Mach number of 2.7 at flight altitude 18.5 km. The flowfields were calculated using the full compressible Navier-Stokes equations with an one-equation turbulence model of Baldwin-Earth. The present calculations were executed based upon a chemically frozen, single perfect gas model assumption. Due to the symmetry of the three-body rocket of each single nozzle, only one fourth of the computational domain was considered for the analysis. The results indicate that a babe heating effect is not considerable due to the small expansion of the plumes. In the base, however, a low speed recirculating flow dominates the region.

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Development of a Platform for Realistic Garment Drape Simulation

  • Kim, Sung-Min;Park, Chang-Kyu
    • Fibers and Polymers
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    • v.7 no.4
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    • pp.436-441
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    • 2006
  • An integrated platform for garment drape simulation system has been developed. In this system, garment patterns from conventional two-dimensional CAD systems can be assembled into a three-dimensional garment on a parametrically resizable realistic human body model. A fast and robust particle-based physical calculation engine has been developed for garment shape generation. Then a series of geometric and graphical techniques were applied to create realistic impressions on simulated garments. This system can be used as the rapid prototyping tool for garments in the future quick-response system.

Numerical study of the effects of periodic body acceleration (PGZ) and bifurcation angle in the stenosed artery bifurcation

  • Ro, Kyoung-Chul;Ryou, Hong-Sun
    • Korea-Australia Rheology Journal
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    • v.21 no.3
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    • pp.175-183
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    • 2009
  • This article describes the numerical investigation of blood flow in the stenosed artery bifurcation with acceleration of the human body. Using the commercial software FLUENT, three-dimensional analyses were performed for six simulation cases with different body accelerations and bifurcation angles. The blood flow was considered to be pulsation flow, and the blood was considered to be a non-Newtonian fluid based on the Carreau viscosity model. In order to consider periodic body acceleration, a modified, time-dependent, gravitational-force term was used in the momentum equation. As a result, flow variables, such as flow rate and wall shear stress, increase with body acceleration and decrease with bifurcation angle. High values of body acceleration generate back flow during the diastolic period, which increases flow fluctuation and the oscillatory shear index at the stenosis.

Adolescent Girls' Bodice Pattern Fit Using the 3-Dimensional Virtual Clothing System (3차원 가상 착의 시스템을 이용한 여자 청소년용 길 원형 맞음새 연구)

  • Kim, Dohkyung;Chun, Jongsuk
    • Human Ecology Research
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    • v.54 no.3
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    • pp.279-292
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    • 2016
  • This research predicted the fit of the basic bodice patterns worn on adolescent girls' 3-dimensional scanned bodies. Six 3-dimensional scanned bodies were selected from the sixth Size Korea data. Each of them had good body posture and represented one of the three garment sizes: 79-160, 82-160, and 85-160. Experimental basic bodice patterns were drafted by three basic bodice pattern making methods. The fit of the basic bodice pattern was analyzed by the CLO 3D virtual clothing system. The results showed that the experimental basic bodice patterns did not fit well at the neck, shoulder, and back for adolescent girls. The fit of the basic bodice patterns varied by pattern making method or size. The basic bodice pattern A with the waist darts ending above the breast line showed the best fit among the three different types of experimental pattern. Among the three sizes 79-160, 82-160, and 85-120, size 79-160 basic bodice pattern showed the worst fit for adolescent girls. The results show that the placement and size of the bodice darts affect the basic bodice pattern fit. The basic bodice pattern making method of size 79-160 for adolescent girls should be studied in a future study.

Design of Brassiere Pattern for Big Size Breast Women -Based on 3D Breast Scanning Data- (유방이 큰 여성을 위한 브래지어 패턴 설계 -3차원 유방 형상 자료를 중심으로-)

  • Han, Chohee;Yi, Kyong-Hwa
    • Journal of the Korean Society of Clothing and Textiles
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    • v.43 no.2
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    • pp.204-214
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    • 2019
  • A CAD program has recently been introduced that can be directly developed into a three-dimensional human body shape and made into a pattern. It is possible to fabricate a bra that reflects the volume and surface area of the breast; however, it still needs to be verified. This study investigates the average size and shape of 20 big-breasted women and designs a brassiere pattern for women with large breasts using a 3D Flattening function of OptiTex PDS v15.6. In addition, the study verifies the reliability of the proposed method compared to a conventional brassiere pattern. The study results are as follows. First, the three dimensional measurement values were smaller than the direct measurement dimensions when the three dimension measurement dimensions of the subjects were compared with the direct measurement dimensions, the replica measurement dimensions and the three dimensional measurement dimensions. Second, the 3D flattening pattern reflects the actual shape, length, and area of the actual breast when comparing a brassiere pattern using a 3D shape and pattern reflecting the direct measurement.

LONGITUDINAL WAVES, STORING AND AMPLIFYING CAPABILITY OF INFORMATION IN WATER MOLECULES AND QUANTUM RESONANCE SPECTROMETER

  • Oh, Hung-Kuk
    • Proceedings of the Korea Society for Energy Engineering kosee Conference
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    • 1996.10b
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    • pp.18-28
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    • 1996
  • The outer-most electrons of metal atoms and the remaining valence electrons of any molecular atoms make three-dimensional crystallizing $\pi$-bondings. The rotating electrons on the three-dimensional crystallizing $\pi$-bonding orbitals of atoms make $\pi$-far infrared rays. Longitudinal wave is a propagation of a bundle of $\pi$-far infrared rays, which are produced by a dynamic impact on a solid bar. The $\pi$-far infrared rays make three-dimensional crystallizing $\pi$-bondings in the material, which reproduce the same $\pi$-far infrared rays. If a current signal is input into water molecules under a given electric potential field with $\pi$-far infrared rays (input information), the signal can be amplified because the $\pi$-far infrared rays make the $\pi$-bondings, which reduce electric resistance. The three-dimensional crystallizing $\pi$-bondings can induce normal electrons to move from one orbital to next one with a aid of potential electric field. Quantum Resonance Spectrometer is composed of tesla coil absorbing $\pi$-far infrared rays, tesla coil emitting varying electromagnetic waves signal generator, signal storage, human body amplifier, signal analyzer and data indicator. The absorbing tesla coil making varying magnetic field and downward and upward electric field, which resonates the $\pi$-far infrared rays coming out from specimen and absorbs them. The modulated current signal from the input square signal can generate and emit varying electromagnetic waves from the tesla coil. The varying electro-magnetic waves make the three-dimensional crystallizing $\pi$-bondings and the $\pi$-far infrared rays in the water molecules.

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Calculation of the incompressible Navier-stokes equations in generalized nonorthogonal body fitted coordinate system (일반 비직교 표면좌표계에서의 비압축성 Navier-Stokes방정식의 수치해석)

  • Gang, Dong-Jin;Bae, Sang-Su
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.20 no.3
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    • pp.1015-1027
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    • 1996
  • In this paper, a numerical procedure for the calculation of the incompressible Navier-Stokes equations in a generalized nonorthogonal body fitted coordinate system is proposed and is validated through three test problems. Present numerical procedure derives the pressure equation by using the pressure substitution method on the regular grid system, and discretized momentum equations are based on the covariant velocity components. Cavity flow, backward facing step flow, and two dimensional channel flow with a sinusoidal wavy wall are chosen as three test problems. Numerical solutions obtained by present procedure shows a good agreement with previous numerical and/or experimental results. Convergence rate is also satisfactory.

Three-Dimensional Volume Analysis of Partial Avascular Necrosis after Talar Neck Fracture (거골 경부 골절 이후 발생한 부분적인 골괴사의 3차원 부피 분석)

  • Na, Woong Chae;Lee, Jun Young;Park, Sang Ha;Park, Hyung Seok
    • Journal of Korean Foot and Ankle Society
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    • v.19 no.4
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    • pp.161-164
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    • 2015
  • Purpose: The purpose of this study is to define the geographic patterns of partial avascular necrosis (AVN) of the talar body and to determine whether there were any predictors of both the location and occurrence of partial AVN. Materials and Methods: Nineteen patients with fracture of the talar neck treated by open reduction and internal fixation and followed up for more than 1 year were analyzed. The radiographs were examined 6 to 8 weeks after the operation for Hawkins sign and if it was not observed, magnetic resonance scans were performed. The three-dimensional analysis was performed using Mimics 17.0 (Materialise). The incidence of collapse and time to operative intervention was recorded. Results: Partial AVN of the talar body was observed in six out of 19 patients. The avascular segment of the talar body was located predominantly in the anterolateral portion. The average volume of the avascular segment was $289mm^3$, and it occupied 1% of total volume of the talus, and 10% of the talar dome. Collapse occurred in one patient in the area of the avascular process. There were no observable trends with regard to Hawkins classification, incidence of collapse, or time to operative intervention to the location of the avascular segment. Conclusion: Partial AVN can occur after fracture of the talar neck. The predominant location of the avascular segment was the anterolateral portion of the talar body. This information may be helpful to understanding the process of avascular necrosis of the talar body.

Estimation of Body Weight Using Body Volume Determined from Three-Dimensional Images for Korean Cattle (한우의 3차원 영상에서 결정된 몸통 체적을 이용한 체중 추정)

  • Jang, Dong Hwa;Kim, Chulsoo;Kim, Yong Hyeon
    • Journal of Bio-Environment Control
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    • v.30 no.4
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    • pp.393-400
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    • 2021
  • Body weight of livestock is a crucial indicator for assessing feed requirements and nutritional status. This study was performed to estimate the body weight of Korean cattle (Hanwoo) using body volume determined from three-dimensional (3-D) image. A TOF camera with a resolution of 640×480 pixels, a frame rate of 44 fps and a field of view of 47°(H)×37°(V) was used to capture the 3-D images for Hanwoo. A grid image of the body was obtained through preprocessing such as separating the body from background and removing outliers from the obtained 3-D image. The body volume was determined by numerical integration using depth information to individual grid. The coefficient of determination for a linear regression model of body weight and body volume for calibration dataset was 0.8725. On the other hand, the coefficient of determination was 0.9083 in a multiple regression model for estimating body weight, in which the age of Hanwoo was added to the body volume as an explanatory variable. Mean absolute percentage error and root mean square error in the multiple regression model to estimate the body weight for validation dataset were 8.2% and 24.5kg, respectively. The performance of the regression model for weight estimation was improved and the effort required for estimating body weight could be reduced as the body volume of Hanwoo was used. From these results obtained, it was concluded that the body volume determined from 3-D of Hanwoo could be used as an effective variable for estimating body weight.

Fast Garment Drape Simulation Using Geometrically Constrained Particle System

  • Kim, Sungmin;Park, Chang-Kyu
    • Fibers and Polymers
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    • v.4 no.4
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    • pp.169-175
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    • 2003
  • A simulation system for versatile garment drape has been developed. Using this system, the shape of a garment can be simulated in consideration of fabric physical properties as well as the interaction between fabrics and other objects. Each fabric piece in a garment is modeled using a geometrically constrained particle system and its behavior is calculated from an implicit numerical integration algorithm in a relatively short time. The system consists of three modules including a preprocessor for the preparation of fabric patterns and external objects, a postprocessor for the results of three-dimensional visualization, and a drape simulation engine. It can be used for the design process of textile goods, garments, furniture, or upholsteries.