• 제목/요약/키워드: THREE-DIMENSIONAL

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A Study on the Possibility of Three-dimensional Wearable Respiration Rate Sensor based on Surface Area Changes (표면적 변화에 기반한 입체적 웨어러블 호흡수 센서의 가능성 탐색)

  • Lee, Seungpyo;Ban, Hyunsung;Lee, Joohyeon
    • Science of Emotion and Sensibility
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    • v.21 no.1
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    • pp.35-44
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    • 2018
  • This study suggests the sensing method of the Three-dimensional respiration rate sensor based on surface area changes, and exploring the design direction of the three-dimensional breathing sensor and the design orientation of the garment. To achieve this, two types of three-dimensional respiration rate sensor were produced, and the study of the dummy and the subjects studied. The study I investigated the possibility of measurement of the three-dimensional respiration sensor by the study variables of the sensor type and speed of respiration. The study II proposes a suitable type of sensor for each of the three measuring positions in addition to the study variables in the study I. To evaluate accuracy, reproducibility, and reliability of the three-dimensional respiration rate sensor, the BIOPAC was used to measure the respiration rate simultaneously with the three-dimensional respiration rate sensor. Through all these results of the experiment, it explored the possibility of measurement of the three-dimensional respiration sensor for the dummy. It also proposed a suitable type of sensor by measuring the respiration rate for the human body.

3-D Kinematic Analysis According to Open Stance Patterns During Forehand Stroke in Tennis (테니스 포핸드 스트로크 동안 오픈스탠스 조건에 따른 3차원 운동학적 분석)

  • Choi, Ji-Young;Kim, Ro-Bin
    • Korean Journal of Applied Biomechanics
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    • v.15 no.3
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    • pp.161-173
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    • 2005
  • Recently among several tennis techniques forehand stroke has been greatly changed in the aspect of spin, grip and stance. The most fundamental factor among the three factors is the stance which consists of open, square and closed stance. The purpose of this study was to investigate the relations between the segments of the body, the three dimensional anatomical angle according to open stance patterns during forehand stroke in tennis. For the movement analysis three dimensional cinematographical method(APAS) was used and for the calculation of the kinematic variables a self developed program was used with the LabVlEW 6.1 graphical programming(Johnson, 1999) program. By using Eular's equations the three dimensional anatomical Cardan angles of the joint and racket head angle were defined 1. In three dimensional maximum linear velocity of racket head the X axis showed $11.41{\pm}5.27m/s$ at impact, not the Y axis(horizontal direction) and the z axis(vertical direction) maximum linear velocity of racket head did not show at impact but after impact this will resulted influence upon hitting ball It could be suggest that Y axis velocity of racket head influence on ball direction and z axis velocity influence on ball spin after impact. the stance distance between right foot and left foot was mean $74.2{\pm}11.2m$. 2. The three dimensional anatomical angular displacement of shoulder joint showed most important role in forehand stroke. and is followed by wrist joints, in addition the movement of elbow joints showed least to the stroke. The three dimensional anatomical angular displacement of racket increased flexion/abduction angle until the impact. after impact, The angular displacement of racket changed motion direction as extension/adduction. 3. The three dimensional anatomical angular displacement of trunk in flexion-extension showed extension all around the forehand stroke. The angular displacement of trunk in adduction-abduction showed abduction at the backswing top and adduction around impact. while there is no significant internal-external rotation 4. The three dimensional anatomical angular displacement of hip joint and knee joint increased extension angle after minimum of knee joint angle in the forehand stroke, The three dimensional anatomical angular displacement of ankle joint showed plantar flexion, internal rotation and eversion in forehand stroke. it could be suggest that the plantar pressure of open stance during forehand stroke would be distributed more largely to the fore foot. and lateral side.

Three-Dimensional Analysis of the Shapes of Gathered Skirts (개더스커트 형상프로포션의 3차원적 해석)

  • Lee, Myung-Hee;Jung, Hee-Kyeong
    • Journal of the Korean Society of Clothing and Textiles
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    • v.30 no.11 s.158
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    • pp.1598-1607
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    • 2006
  • The purpose of this study was to analyze the proportion of gathered skirts using a three-dimensional measurement system. And in this experiment, we have attempted to accumulate three-dimensional data of wearing model and find out adequate methods for analyzing shape of clothes. The experimental design consists of two factorial designs. We established three different kinds of fabrics, ratio of gathers. The measurement tool for three-dimensional model was whole body 3D scanner(Exima-WBS2H). Analysis program used in experiment is RapidForm 2004 PP1 and Pattern Design 2000. Data analysis utilizes SPSS WIN 10.0 Package. As the results show, there were different effect of gather and proportion of shapes among the measurements of width, thickness and areas made by different lines of vision in cross-sectional silhouette. And there were difference shapes of section area at each part of gathered skirts between vertical-outline silhouette and vortical-plane silhouette made by gathering conditions. And also the cross-sectional silhouettes and vertical silhouettes were related to shape of clothes.

Analysis of the J-integral for Two-dimensional and Three-dimensional Crack Configurations in Welds of Steel Structure (강구조물 응접접합부의 2차원 및 3차원 균열에 대한 J-적분 해석)

  • 이진형;장경호
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2004.10a
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    • pp.270-277
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    • 2004
  • In this paper, path-independent values of the J-integral in the fininte element context for arbitrary two-dimensional and three-dimensional crack configurations in welds are presented. For the fracture mechanics analysis of cracks in welds, residual stress analysis and fracture analysis must be performed simultaneously. In the analysis of cracked bodies containing residual stress, the usual domain integral formulation results in path-dependent values of the J-integral. This paper discusses modifications of the conventional J-integral that yield path independence in the presence of residual stress generated by welding. The residual stress problem is treated as an initial strain problem and the J-integral modified for this class of problem is used. And a finite element program which can evaluate the J-integral for cracks in two-dimensional and three-dimensional residual stress bearing bodies is developed using the modified J-integral definition. The situation when residual stress only is present is examed as is the case when mechanical stresses are applied in conjunction with a residual stress field.

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PERFORMANCE ANALYSIS OF NREL PHASE VI WIND TURBINES UNDER VARIOUS SCALE CONDITIONS (스케일 변화에 따른 NREL PHASE VI 풍력터빈의 성능해석)

  • Park, Y.M.;Chang, B.H.
    • 한국전산유체공학회:학술대회논문집
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    • 2006.10a
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    • pp.155-158
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    • 2006
  • In the present paper, the scale effects of two-dimensional airfoil and three-dimensional wind turbine were investigated by using FLUENT software. For two dimensional analysis, flow around S809 airfoil with various Reynolds No. and Mach No. conditions were simulated. For three dimensional analysis, scaled NREL Phase VI wind turbine models from 6% to 1,600% were simulated under the same tip speed ratio condition. Finally, aerodynamic comparisons between two-dimensional flow and three dimensional wind turbine flow are made for the feasibility study of scale effect corrections. Currently, KARI(Korea Aerospace Research Institute) is preparing for the wind tunnel test of 12% NREL Phase VI wind turbine and the performance analysis of the scaled NREL wind turbine model will be validated by the wind tunnel test.

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Design of Flexible Die Punch and Control System for Three-dimensional Curved Forming Surface (3차원 성형곡면 구현을 위한 가변금형의 펀치 및 제어시스템 설계)

  • Seo, Y.H.;Heo, S.C.;Ku, T.W.;Kim, J.;Kang, B.S.
    • Transactions of Materials Processing
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    • v.20 no.3
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    • pp.206-213
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    • 2011
  • A flexible die, which is composed of a number of punches with adjusted heights to form a three-dimensional curved surface, is a crucial part of a flexible forming technology. In this study, the punch and control system of the flexible die were designed. The flexible die is divided into three modules, namely, punch, control and joint, and the corresponding modules were developed. The punch module materializes a three-dimensional forming surface by the control module, which is composed of an AC servo motor set and a linear guide. The joint module is necessary for the sequential motion between the servo motor set and the punch module. A sequential motion algorithm for the AC servo motor set, that uses the data of the punch relative heights, was also proposed. Finally, a flexible stretch forming test was carried out using the presently designed flexible die.

Three dimensional seismic and static stability of rock slopes

  • Yang, X.L.;Pan, Q.J.
    • Geomechanics and Engineering
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    • v.8 no.1
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    • pp.97-111
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    • 2015
  • The kinematical approach of limit analysis is used to estimate the three dimensional stability analysis of rock slopes with nonlinear Hoek-Brown criterion under earthquake forces. The generalized tangential technique is introduced, which makes limit analysis apply to rock slope problem possible. This technique formulates the three dimensional stability problem as a classical nonlinear programming problem. A nonlinear programming algorithm is coded to search for the least upper bound solution. To prove the validity of the present approach, static stability factors are compared with the previous solutions, using a linear failure criterion. Three dimensional seismic and static stability factors are calculated for rock slopes. Numerical results of indicate that the factors increase with the ratio of slope width and height, and are presented for practical use in rock engineering.

Development of High-Performance FEM Modeling System Based on Fuzzy Knowledge Processing

  • Lee, Joon-Seong
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.4 no.2
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    • pp.193-198
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    • 2004
  • This paper describes an automatic finite element (FE) mesh generation for three-dimensional structures consisting of tree-form surfaces. This mesh generation process consists of three subprocesses: (a) definition of geometric model, (b) generation of nodes, and (c) generation of elements. One of commercial solid modelers is employed for three-dimensional solid structures. Node is generated if its distance from existing node points is similar to the node spacing function at the point. The node spacing function is well controlled by the fuzzy knowledge processing. The Voronoi diagram method is introduced as a basic tool for element generation. Automatic generation of FE meshes for three-dimensional solid structures holds great benefits for analyses. Practical performances of the present system are demonstrated through several mesh generations for three-dimensional complex geometry.

Modeling and Simulation of Human Knee Joint in Three Dimension By Using the Method of Optimal Triangular Patches (최단 거리 삼각형 패치 형성법을 이용한 무릎 관절의 3차원 형상 모델링과 시뮬레이션)

  • Moon, Byung-Young;Son, Kwon;Kim, Kwang-Hoon;Seo, Jung-Tak
    • Journal of the Korean Society for Precision Engineering
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    • v.20 no.12
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    • pp.205-212
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    • 2003
  • Many people are exposed to accidents by vehicles or sports. The most frequent injuries by these accidents is concerned with a knee joint. The three-dimensional surface model of a knee is needed for dynamic analysis of knee motion and knee reconstruction. three-dimensional motion data of a knee joint were obtained using X-ray and precise magnetic sensors. The surface data of a femur and a tibia were obtained using cross-sectional pictures by CT. The three-dimensional surface models of a femur and a tibia were made by the method of optimal triangular patch. Using obtained motion data, we simulated the motion of three-dimensional knee joint model.

Three-Dimensional Rotordynamic Analysis Considering Bearing Support Effects (베어링 지지 효과를 고려한 3 차원 로터동역학 해석)

  • Park, Hyo-Keun;Kim, Dong-Hyun;Kim, Myung-Kuk;Chen, Seung-Bae
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2006.05a
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    • pp.902-909
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    • 2006
  • In this study, three-dimensional rotordynamic analyses have been conducted using equivalent beam, hybrid and fun three-dimensional models. The Present computational method is based on the general finite element method with rotating gyroscopic effects of a rotor system. General purpose commercial finite element code, SAMCEF which includes practical rotordynamics module with various types of rotor analysis methods and bearing elements is applied. For the purpose of numerical verification, comparison study for a benchmark rotor model with support bearings is performed first. Detailed finite element models based on three different modeling concepts are constructed and then computational analyses are conducted for the realistic and complex three-dimensional rotor system. The results for rotor stability and mass unbalance response are presented and compared with the experimental vibration test conducted in this study.

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