• Title/Summary/Keyword: subdivision method

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Research for the 5 axis machining simulation system with Octree Algorithm (옥트리에 기반한 5 축 가공 시뮬레이션을 위한 연구)

  • Kim Y.H.;Ko S.L.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.06a
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    • pp.956-959
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    • 2005
  • The overall goal of this thesis is to develop a new algorithm based on the octree model for geometric and mechanistic milling operation at the same time. Most commercial machining simulators are based on the Z map model, which has several limitations in terms of achieving a high level of precision in five-axis machining simulation. Octree representation being a three-dimensional (3D) decomposition method, an octree-based algorithm is expected to be able to overcome such limitations. With the octree model, storage requirement is reduced. Moreover, recursive subdivision is processed in the boundaries, which reduces useless computations. To achieve a high level of accuracy, fast computation time and less memory consumption, the advanced octree model is suggested. By adopting the supersampling technique of computer graphics, the accuracy can be significantly improved at approximately equal computation time. The proposed algorithm can verify the NC machining process and estimate the material removal volume at the same time.

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A Study on Knowledge Classification of Cadastral Science (지적학의 학문분류체계에 관한 연구)

  • Kworn, Kie-Won;Kim, Bee-Yeon
    • Journal of the Korean Society for Library and Information Science
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    • v.40 no.1
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    • pp.39-57
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    • 2006
  • Cadastral Science has not been evaluated as an independent discipline according to Code of Research Fields of Korea Research Foundation. The purpose of this study is to find the problems of knowledge classification of Cadastral Science and suggest method of improvement. For the studying, analyzes the definition, objects of research, educational system and curriculum of Cadastral Science. Besides, investigates the condition of Cadastre classification on Code of Research Fields, DDC and KDC. This paper suggests that Cadastral Science can be restructured to the new Interdisciplinary Studies and moved to the upper division. The items of division and subdivision can be also added.

Treatment Rate-up Methods in the Oriental Medicine (한의학 치료율 제고 방안에 관한 연구)

  • Lee Sun-Dong
    • Journal of Society of Preventive Korean Medicine
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    • v.3 no.1
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    • pp.35-54
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    • 1999
  • This thesis shows about the meaning of treatment rate increasing, the current treated level and the reason of low treatment rate and increasing methods. 1. Treatment rate incresing means high treat level within short time, keeping treatment effect for a long time as well as raising treatment rate. 2. The current by diseases each others completed treatment rate of oriental medicine is 14.0% to 89.7%$(mean:\;{\pm}40.0%)$. Therefore the rate is show too low. 3. The reasons of low treatment rate; low academic level of oriental, academic limitation, clinic and prevention problem of oriental medicine, lack of medical approch suitable for current diseases and symptoms, mostly incurrable diseases using oriental medicine, lack of preventive education, disappropriate medical service and nonspecialty of the treatment, etc. 4. The next methods for incresing the treatment rate must be improved; such as accurate establishment of process that diagnosis symptoms and treats them, system research of microdiagnosis, positive treatment with medicine and nonmedicine method at the same time, appropriate subdivision and actualization of clinical basic research, research of dose and response, diversity of treatment methods and forms, development of treatment service and prevention based on health level, enormous change as cure medicine and opening-up of new disease field, specialization of medical examination, reinforcement of public medical part and herbal drugs use with same origin, mental and pysical stability of patients, accurate extract and oral drinking ways, etc.

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A Study on the Facet Structure of Life Science and Literature in DDC (DDC의 패싯 구조에 대한 연구 -생명과학과 문학을 중심으로-)

    • Journal of Korean Library and Information Science Society
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    • v.30 no.3
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    • pp.53-96
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    • 1999
  • This study intends to : 1) confirm the possibility to transform the enumerated scheme into the faceted scheme, 2) review general theories on facet structure employed in DDC of the enumerated scheme, 3) analyze the facet structure of life science and literature in DDC, and 4) comparison of the facet structure of life science and literature in DDC and CC. This study suggests following conclusions. 1) CC follows throughly the classification principles by Ranganathan, but all classification theories are not property applied to DDC yet. 2) Because DDC does not have any formula to classify the compound subject, but has to follow the compounding methods presented in each subject, its facet structure is too complicated. 3) DDC has transformed the entire system into the facet structure through its revision. Expecially the life science transformed into the facet structure employed the facet indicators and applies them to all the systems in life science. But the notations have sometimes twofold meanings, and no ability to differentiate the meanings in the same notation,. When DDC follows the classification method by facet, the number of items for classification so limited that it is difficult to array the subdivision and that length of notation becomes longer and longer.

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Study on Statistical Method for Objective Evaluation of Tunnel Portal Slopes (객관적인 터널 갱구사면 평가를 위한 통계기법 연구)

  • Kwon, O-Il;Baek, Yong;Na, Jong-Hwa;Seo, Yong-Seok;Kim, Gyo-Won
    • Proceedings of the Korean Geotechical Society Conference
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    • 2006.03a
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    • pp.634-643
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    • 2006
  • This study was intended to develop a high reliable technique by statistically processing on-site data with a general linear model, providing the basic data for construction, analysis of stability and establishment of maintenance measures for tunnel portal slopes in the future. This study evaluated the stability of a tunnel portal slope using a quantified technique, which is based on a general linear model. The important scores of each independent variable were allocated by using the ranges of the quantified values, based on the predicted coefficient of regression and the scores for categories of each independent variable were allocated so that those are equally spaced. The quantification model obtained from the results of evaluating the total data used for the quantification process provided precise results. In addition, it is expected that a more detail subdivision of response variables and sufficient data would produce a better stability evaluation standard.

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The Effects of Organizational Structure of Hospital on the Conflict Patterns of Human Resources (의료기관 조직구조가 인적자원의 갈등양상에 미치는 영향)

  • Im, Bockhee;Park, Jikyeong
    • Korea Journal of Hospital Management
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    • v.23 no.3
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    • pp.63-71
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    • 2018
  • The purpose of this study is to explore how the organizational structure of hospitals affects the pattern of conflicts between human resources at hospitals and then to present basic data necessary for conflict resolution. Research data were collected from the personnel of 14 hospitals in P city in Korea. The findings of the study are summed up as follows. First, administrative workers and with fewer years of service thought of the organizational structure as organic. Second, organizational conflict was found to be higher in those at older ages, with more years of service and in middle management positions. Next, as for conflict patterns between occupation types, nurses showed more conflicts with doctors and administrative workers, while administrative workers and public health personnel had more conflicts with nurses. Last, of the organizational structure factors, 'Subdivision of work,' 'Decision making method,' 'Opinion collection process,' 'Codification of responsibilities and rights' and 'Documentation of duties' were found to have negative effects on conflict patterns. Therefore, the findings imply that for decrease in organizational conflicts, hospitals need to be reorganized to have a more organic structure and take such differentiated measures for conflict resolution that consider characteristics of human resources, such as one's age, years of service and position.

An Efficient Triangulation Algorithm for Trimmed NURBS Surfaces (트림된 NURBS 곡면의 효율적인 삼각화 알고리즘)

  • 정재호;박준영
    • Korean Journal of Computational Design and Engineering
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    • v.5 no.2
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    • pp.144-154
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    • 2000
  • We propose an algorithm for obtaining a triangular approximation of a trimmed NLRBS surface. Triangular approximation is used in the pre-processing step of many applications such as RP(Rapid Prototyping), NC(Numerical Control) and FEA(Finite Element Analysis), etc. The algorithm minimizes the number of triangular elements within tolerance and generates a valid triangular mesh for STL file and NC tool path generation. In the algorithm, a subdivision method is used. Since a patch is a basic element of triangular mesh creation, boundary curves of a patch are divided into line segments and the division of curves is applied for the interior of the surface. That is, boundary curves are subdivided into line segments and two end points of each line segment are propagated to the interior of the surface. For the case of a trimmed surface, triangulation is carried out using a model space information. The algorithm is superior because the number of elements can be controlled as the curvature of the surface varies and it generates the triangular mesh in a trimmed region efficiently. To verify the efficiency, the algorithm was implemented and tested for several 3D objects bounded by NURBS surfaces.

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Handle analysis of Cosmetic Textiles and its Correlation with Subjective haracteristics -Focus on puff textile-

  • Jung, Cheul Sun;Koo, Young Seok
    • Fashion & Textile Research Journal
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    • v.16 no.2
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    • pp.312-318
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    • 2014
  • This study examined the correlation between a handle evaluation of cosmetic puff textile and a sensory evaluation. The KES-F system was used to analyze the main mechanical factors for the handle evaluation and a statistical method was used for the sensory evaluation. The results revealed different mechanical properties and handle values of the tested cosmetic puff textiles. A material type and structure of the cosmetic textile affected the handle property of the material which is the most important factor for a cosmetic purpose. Particularly, the physical properties of textile material are likely to be important factors for the sensory property of cosmetic material. In addition, the sensory evaluation also revealed different sensory characteristics of the cosmetic efficiency according to the cosmetic puff textile. No close relationship was observed between the mechanical properties and sensory evaluation on the cosmetic puff textiles. The sensory evaluation of a cosmetic efficiency is not only decided by the physical and mechanical characteristics of the cosmetic textile material. Overall, when using textiles used for the cosmetic purposes, it is important to consider not only the proper mechanical properties of the textiles but also the use and sensory satisfaction. Development and selection of the cosmetic textiles should be focused on both the material function and consumer satisfaction.

A Study on the Development of Shape Functions of Polyhedral Finite Elements (다면체 유한요소의 형상함수 개발에 관한 연구)

  • Kim, Hyun-Gyu
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.27 no.3
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    • pp.183-189
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    • 2014
  • In this paper, a polyhedral element is presented to solve three-dimensional problems by developing shape functions based on Wachspress coordinates and moving least square approximation. A subdivision of polyhedrons into tetrahedral domains is performed for the construction of shape functions of polyhedral elements, and numerical integration of the weak form is carried out consistently over the tetrahedral domains. The weight functions for moving least square approximation are defined by solving Laplace equation with boundary values based on Wachspress coordinates on polyhedral element faces. Polyhedral elements presented in this paper have similar properties to conventional finite element regarding the continuity, the completeness, the node-element connectivity and the inter-element compatibility. Numerical examples show the effectiveness of the present method for solving three-dimensional problems using polyhedral elements.

An Improvement on low Speed Operation Performances of DTC for 3-level Inverter-fed Induction Motors (3레벨 인버터로 구동되는 유도전동기 직접토크제어의 저속성능 개선)

  • Lee, Kyo-Beum;Song, Joong-Ho;Choy, Ick;Kim, Kwang-Bae;Yoo, Ji-Yoon
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.49 no.10
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    • pp.693-700
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    • 2000
  • A direct torque control algorithm for 3-level inverter-fed induction motors is presented. Conventional voltage selection methods provoke some problems such as stator flux drooping phenomenon and undersirable torque control appeared especially at the low speed operation. To overcome these problems, a proposed method uses intermediate voltage vectors, which are inherently generated in 3-level inverters. In the proposed algorithm, both subdivision of the basic switching sectors and applications of tntermediated voltages improve the low speed operation characteristics. This algorithm basically considers applications in which direct torque controlled induction motors are fed by 3-level inverters with low switching frequency around 500Hz. An adaptive observer is also employed to bring better responses at the low speed operation, by estimating some state-variables, motor speed and motor parameters which take a deep effect on the performance of the low speed operation. Simulation and experiment results verify effectiveness of the proposed algorithm.

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