• Title/Summary/Keyword: Geometric Data

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A Study on Pattern Using Geometric Interpretation of Stacks Silhouette (슬랙스 실루엣의 도형적 해석을 이용한 패턴 연구)

  • 강석경;임원자
    • Journal of the Korean Society of Clothing and Textiles
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    • v.21 no.5
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    • pp.807-820
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    • 1997
  • This exploratory research was intended to develop and test a slacks pattern based upon conic model. Data came from measurements of photograph of three subjects. Silhouette of slacks was close fit on waist and hip and loose under hip level. This three-dimensional form was modeled with truncated cones. This conic model was truncated by plane of the waist level, the abdomen level, the hip level, the crotch level and the ankle level parallel to the floor. Two models that have differences in back part of the model were tested. Drafted patterns from two models were taken for each subject. Drafted experimental pattern was operated for slacks pattern. The first step was to make sideseam. Parts over crotch level were moved to both sides. And then to make waistdarts. Experimental pattern had two darts each in front and back. Each experimental slacks was evaluated by sensory test to appearance and comfort by five judges. The results can be summarized as follows. 1) Appearance and comfort of experimental pattern were judged to be satisfactory. Especially these patterns were fitted we18 in waist darts front and back. So we evaluated that was proper pattern for slacks. 2) Model 2 was better in appearance than model 1. But Model 1 was more comfortable in non significant difference. This was supposed to be resulted from fit more closely of model 2. 3) considering preceding results, this geometric model based upon truncated cone was applicable for slacks pattern.

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Dilution of Precision (DOP) Based Landmark Exclusion Method for Evaluating Integrity Risk of LiDAR-based Navigation Systems

  • Choi, Pil Hun;Lee, Jinsil;Lee, Jiyun
    • Journal of Positioning, Navigation, and Timing
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    • v.9 no.3
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    • pp.285-292
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    • 2020
  • This paper introduces a new computational efficient Dilution of Precision (DOP)-based landmark exclusion method while ensuring the safety of the LiDAR-based navigation system that uses an innovation-based Nearest-Neighbor (NN) Data Association (DA) process. The NN DA process finds a correct landmark association hypothesis among all potential landmark permutations using Kalman filter innovation vectors. This makes the computational load increases exponentially as the number of landmarks increases. In this paper, we thus exclude landmarks by introducing DOP that quantifies the geometric distribution of landmarks as a way to minimize the loss of integrity performance that can occur by reducing landmarks. The number of landmarks to be excluded is set as the maximum number that can satisfy the integrity risk requirement. For the verification of the method, we developed a simulator that can analyze integrity risk according to the landmark number and its geometric distribution. Based on the simulation, we analyzed the relationship between DOP and integrity risk of the DA process by excluding each landmark. The results showed a tendency to minimize the loss of integrity performance when excluding landmarks with poor DOP. The developed method opens the possibility of assuring the safety risk of the Lidar-based navigation system in real-time applications by reducing a substantial amount of computational load.

Adaptation of Motion Capture Data of Human Arms to a Humanoid Robot Using Optimization

  • Kim, Chang-Hwan;Kim, Do-Ik
    • 제어로봇시스템학회:학술대회논문집
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    • 2005.06a
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    • pp.2126-2131
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    • 2005
  • Interactions of a humanoid with a human are important, when the humanoid is requested to provide people with human-friendly services in unknown or uncertain environment. Such interactions may require more complicated and human-like behaviors from the humanoid. In this work the arm motions of a human are discussed as the early stage of human motion imitation by a humanoid. A motion capture system is used to obtain human-friendly arm motions as references. However the captured motions may not be applied directly to the humanoid, since the differences in geometric or dynamics aspects as length, mass, degrees of freedom, and kinematics and dynamics capabilities exist between the humanoid and the human. To overcome this difficulty a method to adapt captured motions to a humanoid is developed. The geometric difference in the arm length is resolved by scaling the arm length of the humanoid with a constant. Using the scaled geometry of the humanoid the imitation of actor's arm motions is achieved by solving an inverse kinematics problem formulated using optimization. The errors between the captured trajectories of actor arms and the approximated trajectories of humanoid arms are minimized. Such dynamics capabilities of the joint motors as limits of joint position, velocity and acceleration are also imposed on the optimization problem. Two motions of one hand waiving and performing a statement in sign language are imitated by a humanoid through dynamics simulation.

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Integration of History-based Parametric CAD Model Translators Using Automation API (오토메이션 API를 사용한 설계 이력 기반 파라메트릭 CAD 모델 번역기의 통합)

  • Kim B.;Han S.
    • Korean Journal of Computational Design and Engineering
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    • v.11 no.3
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    • pp.164-171
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    • 2006
  • As collaborative design and configuration design are of increasing importance in product development, it becomes essential to exchange the feature and parametric CAD models among participants. A history-based parametric method has been proposed and implemented. But each translator which exchanges the feature and parametric information tends to be heavy because to implement duplicated functions such as the identification of the selected geometries, mapping between features which have different attributes. Furthermore. because the history-based parametric translator uses the procedural model as the neutral format, which is the XML macro file, the history-based parametric translators need a geometric modeling kernel to generate an internal explicit geometric model. To ease the problem, we implemented a shared integration platform, the TransCAD. The TransCAD separates translators from the XML macro files. The translators for various CAD systems need to communicate with only the TransCAD. To support the communication with the TransCAD, we exposed the functions of the TransCAD by using the Automation APIs, which is developed by Microsoft. The Automation APIs of the TransCAD consist of the part modeling functions, the data extraction functions, and the utility functions. Each translator uses these functions to translate a parametric CAD model from the sending CAD system into the XML format, or from the in format into the model of the receiving CAD system This paper introduces what the TransCAD is and how it works for the exchange of the feature and parametric models.

A Study on the Usage and Pattern of Jacquard Fabrics (자카드직물의 용도와 문양 연구)

  • Chin, Young-Gil;Song, Gyeong-Ja
    • Journal of the Korean Society of Fashion and Beauty
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    • v.4 no.2 s.8
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    • pp.50-64
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    • 2006
  • This study was performed the analysis on the final usage and the pattern type of Jacquard fabrics through the surveyed data from the domestic and foreign textile fashion magazines[Book Moda, Fashion biz, Vogue] during recent 5 years(2000-2004). The result of this study can be summarized as follows. 1 Jacquard fabric mostly applies to apparel followed by accessory, interior decoration and bedding. As classified by uses, in apparel, it applies to One-pieces most followed by jackets and coats. In interior decoration, Slipcover uses Jacquard fabric most and then cushions, curtains and carpets. In accessory, neck ties use it most and then hand bags, hats and mufflers. In bedding, Jacquard fabric evenly applies to sheets, pillows, blankets and coverlet. 2. As classified by uses above, flowered patterns apply to each use most followed by geometric patterns, abstract patterns, ethnic patterns, art patterns and animal patterns. In addition, flowered patterns apply to apparel most and then interior decoration, accessory and bedding. Geometric patterns apply to apparel, accessory, interior decoration and bedding orderly. It is researched that abstract patterns and ethnic patterns also apply to apparel partially.

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A Study on the Hair style in Respect of Fashion Trend in 1960's (1960년대 패션트렌드에 따른 헤어스타일의 양상)

  • Yoo, Mee-Geum;Choi, Jung-Soon
    • Journal of the Korean Society of Fashion and Beauty
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    • v.2 no.2 s.2
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    • pp.1-11
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    • 2004
  • The purpose of this study was to analyze the hair style trend in the respect of fashion trend in 1960s. The study also attempted if there were significant influences to current hair designers and hair styles as beehive, mods hair, short cut. geometric cut, wigs, natural hair, unisex hair. This study is a descriptive study, involving the collection of picture data and examine the art of the 1960's. Because 1960's is a revolutionary decade in the way of living and fashion trend. This study also adopted review of literature and analysis of magazines. 1960's was a period of major street fashion as Mods, Jackie Look, Miniskirt, Pop Art, Op Art Look, Space Look, Hippie Look, Unisex Look. The results of this study can be summarized as follows: 1) A review of literature had shown that little or no studies for an in depth analysis of 1960's fashion trend and hair design. 2) During the sixties, the trend of fashion and hair style were remarkable change in the way of living. 3) There were strong influences hair styles of 1960's until today.

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Spatial Complex Envelope of Acoustic Field : Its Definition and Characteristics (음장의 공간 복소 포락: 정의와 특성)

  • Park, Choon-Su;Kim, Yang-Hann
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.17 no.8
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    • pp.693-700
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    • 2007
  • We can predict spatial acoustic pressure distribution on the plane of interest by using acoustic holography. However, the information embedded in the distribution plot is usually much more than what we need: for example, source locations and their overall propagation pattern. One possible candidate to solve the problem is complex envelope analysis. Complex envelope analysis extracts slowly-varying envelope signal from a band signal. We have attempted to extend this method to space domain so that we can have spatial information that we need. We have to modulate two dimensional data for obtaining spatial envelope. Although spatial modulation basically follows the same concept that is used in time domain, the algorithm for the spatial modulation turns out to be different from temporal modulation. We briefly describe temporal complex envelope analysis and extend it to spatial envelope of 2-D acoustic field by introducing geometric transformation. In the end, the results of applying the spatial envelope to the holography are envisaged and verified.

On the elastic parameters of the strained media

  • Guliyev, Hatam H.
    • Structural Engineering and Mechanics
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    • v.67 no.1
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    • pp.53-67
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    • 2018
  • The changes of parameters of pressure and velocity of propagation of elastic pressure and shear waves in uniformly deformed solid compressible media are studied within the nonclassically linearized approach (NLA) of nonlinear elastodynamics to create a new theoretical basis of the geomechanical interpretation of various groups of geophysical observational and experimental data. The cases of small and large deformations are considered while their describing by various elastic potentials, i.e., problems considering the physical and geometric nonlinearity. Convenient analytical formulae are obtained to calculate the indicated parameters in the deformed isotropic media within the nonclassical linear and nonlinear solution in the NLA. Specific numerical experiments are conducted in case of overall compression of various materials. It is shown that the method (generally accepted in the studies of mechanics of standard constructional materials) of additional linearization (relative to the pressure parameter) in the basic correlations of the NLA introduces substantial quantitative and qualitative errors into the results at significant preliminary deformations. The influences of the physical and geometric nonlinearity on the studied characteristics of the medium are large in various materials and differ qualitatively. The contribution of nonlinear components to the values of the considered parameters prevails over linear components at large deformations. When certain critical values of compression deformations in the medium are achieved, elastic waves with actual velocity cannot propagate in it. The values of the critical deformations for pressure and shear waves differ within different elastic potentials and variants of the theory of initial deformations.

OPTIMAL SHAPE DESIGN OF A S-SHAPED SUBSONIC INTAKE USING NURBS (NURBS를 이용한 S형 천음속 흡입관 최적 설계)

  • Lee B.J.;Kim C.
    • Journal of computational fluids engineering
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    • v.11 no.1 s.32
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    • pp.57-66
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    • 2006
  • An optimal shape design approach is presented for a subsonic S-shaped intake using aerodynamic sensitivity analysis. Two-equation turbulence model is employed to capture strong counter vortices in the S-shaped duct more precisely. Sensitivity analysis is performed for the three-dimensional Navier-Stokes equations coupled with two-equation turbulence models using a discrete adjoint method For code validation, the result of the flow solver is compared with experiment data and other computational results of bench marking test. To study the influence oj turbulence models and grid refinement on the duct flow analysis, the results from several turbulence models are compared with one another and the minimum number of grid points, which can yield an accurate solution is investigated The adjoint variable code is validated by comparing the complex step derivative results. To realize a sufficient and flexible design space, NURBS equations are introduced as a geometric representation and a new grid modification technique, Least Square NURBS Grid Approximation is applied With the verified flow solver, the sensitivity analysis code and the geometric modification technique, the optimization of S-shaped intake is carried out and the enhancement of overall intake performance is achieved The designed S-shaped duct is tested in several off-design conditions to confirm the robustness of the current design approach. As a result, the capability and the efficiency of the present design tools are successfully demonstrated in three-dimensional highly turbulent internal flow design and off-design conditions.

Configuration Planning of an Actively Articulated Suspension to Vehicle Orientation Control on Unstructured Terrain (험지에서의 가변 휠형 무인 자율차량의 자세 제어를 위한 가변 휠의 형상 계획)

  • Lim, Kyeong-Bin;Park, Suk-Hoon;Yoon, Yong-San;Lee, Sang-Hoon;Kang, Shin-Cheon
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.33 no.3
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    • pp.251-260
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    • 2009
  • Hybrid locomotive UGV with actively articulated legs along with wheeled ends has high traversability to travel over rough terrain. The behavior control method was usually adapted for the controlling of the suspension configuration which determines the traversability of the UGV. In this study, we are proposing a method of configuration planning of the legs without any detail geometric data about the terrain. The terrain was estimated by the traces of each wheel and the leg configurations for the desired posture of the vehicle were set up against the constraints of the terrain. Also, an optimal leg configuration was calculated based on the quasi-static stability and power consumption, and plans for the leg behavior were made. Validity of the proposed method was checked by simulations using some off-the-shelf programs, and showed that the orientation control without geometric features of terrains and simplification of the behavior planning for obstacle negotiation were possible.