• 제목/요약/키워드: Shape Control

검색결과 3,158건 처리시간 0.032초

정상체중 여고생들의 체중조절행위와 관련된 요인에 관한 연구 (Factors Associated with Weight Control Behaviors Among High School females with Normal Body Weight)

  • 김옥수;윤희상
    • 대한간호학회지
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    • 제30권2호
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    • pp.391-401
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    • 2000
  • This descriptive study was designed to identify the factors associated with weight control behaviors among 273 high school girls with normal body weight. The objectives of the study were ⅰ) to evaluate subjective obesity and satisfaction with the body shape, ⅱ) to describe the weight control behaviors and the motivation, ⅲ) to reveal the relationships between the weight control behaviors and BMI (Body Mass Index), iv) to investigate the relationships between the weight control behaviors and subjective obesity and satisfaction with the body shape, and v) to investigate the relationships between the weight control behaviors and family support. The results showed that 62.6% of the adolescent girls with normal weight perceived that they were fatty and 9.9% thought they were obese. Seventy-five percent of them were not satisfied with their body shape. Eighty percent of the participants reported the main motivation of weight control was to have an attractive appearance. In this study, self-reported weight control methods included dieting (64.8%, skipping or reducing meals), exercise (36.6%), and special dieting (20.1%) such as eating an increased amount of juice or vegetables. It was shown that the subjects who were not satisfied with their body shape and perceived themselves as fatty or obese were active in exercise, diet, and other special diets. Subjects who were on diets and special diets had a higher level of BMI than who were not on diet and special diet. Subjects who exercise had a lower level of BMI than who did not exercised. Family support was significantly related to exercise behavior. The research suggested that there is a increasing responsibility for school nurse to instruct on the body shape and weight control behaviors through health education and consultation. Also, the results suggested that it is important to develop proper diet and exercise methods for adolescents girls to maintain their weight and health.

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A Controllable Ternary Interpolatory Subdivision Scheme

  • Zheng, Hongchan;Ye, Zhenglin;Chen, Zuoping;Zhao, Hongxing
    • International Journal of CAD/CAM
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    • 제5권1호
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    • pp.29-38
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    • 2005
  • A non-uniform 3-point ternary interpolatory subdivision scheme with variable subdivision weights is introduced. Its support is computed. The $C^0$ and $C^1$ convergence analysis are presented. To elevate its controllability, a modified edition is proposed. For every initial control point on the initial control polygon a shape weight is introduced. These weights can be used to control the shape of the corresponding subdivision curve easily and purposefully. The role of the initial shape weight is analyzed theoretically. The application of the presented schemes in designing smooth interpolatory curves and surfaces is discussed. In contrast to most conventional interpolatory subdivision scheme, the presented subdivision schemes have better locality. They can be used to generate $C^0$ or $C^1$ interpolatory subdivision curves or surfaces and control their shapes wholly or locally.

삼각망의 형상 변형 (Shape Deformation of Triangular Net)

  • 유동진
    • 한국정밀공학회지
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    • 제24권11호
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    • pp.134-143
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    • 2007
  • A new approach based on mean value coordinate combined with Laplacian coordinate is proposed for shape deformation of a large polygon model composed of triangular net. In the method, the spherical mean value coordinates for closed control meshes is introduced to describe a vertex in the triangle meshes to be deformed. Furthermore, the well known quardratic least square method for the Laplacian coordinates is employed in order to deform the control meshes. Because the mean value coordinates are continuous and smooth on the interior of control meshes, deforming operation of control meshes change the shape of polygon model while preserving the intrinsic surface detail. The effectiveness and validity of this novel approach was demonstrated by using it to deform large and complex polygon models with arbitrary topologies.

최적 제어를 통한 복합적층판의 형상최적화 (Shape Optimization in Laminated Composite Plates by Volume Control)

  • 한석영;백춘호;박재용
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 2003년도 추계학술대회
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    • pp.277-282
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    • 2003
  • The growth-strain method was applied to cutout optimization in laminated composite plates. Since the growth-strain method optimizes a shape by generating the bulk strain to make the distributed parameter uniform, the distributed parameter was chosen as Tsai-Hill value. In this study, of particular interest is to see whether the growth-strain method developed for shape optimization in isotropic media would work for laminated composite Plates. In volume control of the growth-strain method, it makes Tsai-Hill value at each element uniform in laminated composite plates under the predetermined volume. The shapes optimized by Tsai-Hill fracture index were compared with those of the initial shapes for the various load conditions and predetermined volumes of laminated composite plates. As a result, it was verified that volume control of the growth-strain method worked very well for cutout optimization in laminated composite plates.

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고온 금속 표면 결함에 대한 3차원 형상 추출 시스템 개발 (Development of a 3D Shape Reconstruction System for Defects on a Hot Steel Surface)

  • 장유진;이주섭
    • 제어로봇시스템학회논문지
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    • 제21권5호
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    • pp.459-464
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    • 2015
  • An on-line quality control of hot steel products is one of the important issues in the steel industry because of cost minimization. In recent years, relative depth information of surface defects is increasingly required for strict quality control. In this paper, a 3D shape reconstruction scheme for defects on a hot steel surface based on a multi-spectral photometric stereo method is proposed. After simultaneously illuminating a hot steel surface by using vertical/horizontal linearly polarized lights of green and blue light sources, the corresponding 4 images are obtained. The photometric stereo method is then applied with the aid of a GPU (Graphic Processing Unit) to reconstruct the shape of the target surface based on these images. The proposed scheme was validated through experiments.

판재의 드로우비드 성형시 비드표면처리와 비드형상이 인출 및 마찰특성에 미치는 효과 (Effect of Bead Surface Treatments and Bead Shapes on the Drawing and Friction Characteristics in Drawbead Forming of Sheet Metal)

  • 이동활;류종수;정우창;문영훈
    • 열처리공학회지
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    • 제18권2호
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    • pp.105-111
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    • 2005
  • In sheet metal forming, drawbeads are often used to control uneven material flow, which may cause defects such as wrinkles, fractures, surface distortion and springback. Appropriate setting and adjusting of the drawbead force is one of the most important parameters in sheet forming process control. Therefore in this study, drawbead test was performed at various bead surface treatment conditions to clarify the frictional characteristics between sheet and drawbead. Furthermore, the differences in drawing force between circular and rectangular shape beads have also been measured to estimate the effectiveness of bead shape on the material flow control. The results show that drawing and friction characteristic were strongly influenced by surface treatments of bead and bead shapes.

형상제어를 위한 새로운 보강롤의 개발 (Development of New Back-Up Roll for Strip Shape Control)

  • 이원호
    • 대한기계학회논문집A
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    • 제27권2호
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    • pp.327-333
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    • 2003
  • Most of shape defects in steel strip are originated from the structure of rolling mill itself. For instance, strip crown occurs when the work roll is deformed by the bending moment induced on roll chocks. To get rids of the shape defects, it is necessary to increase the stiffness of rolling mill. The structure change of back-up roll is one of alternative ways to increase the mill stiffness without facility revamping from 4 high mill to 6 high mill. In this research work, the new back-up roll was developed and can be used in any type of 4 high mill to reduce the strip shape defects. The developed back-up roll consists of sleeve, arbor and phase angle adjusting system for arbor. The circumference of arbor is specially machined to adapt the strip width change during rolling. The experimental cold rolling test was done to prove the effectiveness of newly developed back-up roll. The experimental rolling results show that the new back-up roll has more powerful performance in reducing the shape defects than conventional back-up roll. It was also found that the new back-up roll has higher stability for shape control. In addition to, the only sleeve surface needs to be reground and changed in most cases, so that the maintenance cost can be greatly reduced.

형상기업합금을 이용한 유량제어밸브의 위치제어 적용 시뮬레이션 (A Simulation Study of Position Control Performance of a Shape Memory Alloy-Actuated Flow Control Valve)

  • 최수현;이한석;국금환
    • 한국정밀공학회지
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    • 제16권8호
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    • pp.79-87
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    • 1999
  • In this study, a new type of flow control valve which is SMA actuated flow control valve is presented. The flow control valve is actuated by a small motion of shape memory alloy. The performance of this valve as a position control component is analyzed by computer simulation. A variable structure control technique is applied for the position control by the flow control valve. The position control performance of the valve is evaluated on the step responses of a PID control by a electrohydraulic servo valve. For the simulation study, first, the mathematical model of a hydraulic system, which is consisted of the flow control valve and a hydraulic cylinder, is formulated. This mathematical model and the designed variable structure control algorithm are then combined by the MATLAB software. The same sequence of work is carried out for the PID position control system with a electrohydraulic servo valve. The simulation results show the validity of the new type of flow control valve as a variable position control component.

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제어기법에 따른 비선형 형상해석의 수렴성 및 효율성 펑가 (An Estimate for Convergence and Efficiency of Nonlinear Shape Analysis According to the Control Techniques)

  • 정을석;전진형;손수덕;김승덕
    • 한국공간구조학회:학술대회논문집
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    • 한국공간구조학회 2006년도 춘계 학술발표회 논문집 제3권1호(통권3호)
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    • pp.214-223
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    • 2006
  • Membrane structures, a kind of lightweight soft structural system, are used for spatial structures. The material property of the membrane has strong axial stiffness, but little bending stiffness. The design procedure of membrane structures are needed to do shape finding, stress-deformation analysis and cutting pattern generation. In shape finding, membrane structures are unstable structures initially. These soft structures need to be introduced initial stresses because of its initial unstable state, and happen large deformation phenomenon. Therefore, in this study, to find the structural shape after large deformation caused by initial stress, we need the shape analysis considering geometric nonlinear term. And we investigate the evaluation of shape analysis technique's convergence and efficiency according to the control method

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다연결체 구조물에 대한 형상 최적화 (Shape Optimization for Multi-Connected Structures)

  • 한석영;배현우
    • 한국자동차공학회논문집
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    • 제8권2호
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    • pp.151-158
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    • 2000
  • The growth-strain method was used for shape optimization of multi-connected structures. It was verified that the growth-strain method is very effective for shape optimization of structures with only one free surface to be deformed. But it could not provide reasonable optimized shape for multi-connected structures, when the growth-strain method is applied as it is. The purpose of this study is to improve the growth-strain method for shape optimization of multi-connected two- and three- dimensional structures. In order to improve, the problems that occurred as the growth-strain method was applied to multi-connected structures were examined, and then the improved method was suggested. The effectiveness and practicality of the developed shape optimization system was verified by numerical examples.

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