• Title/Summary/Keyword: Design Shape

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Free Vibrations of Arches in Cartesian Coordinates (직교좌표계에 의한 아치의 자유진동)

  • Lee, Byoung-Koo;Lee, Yong-Soo;Kim, Il-Jung;Choi, Kou-Moon
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.12 no.12
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    • pp.970-978
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    • 2002
  • The differential equations governing free vibrations of the elastic arches with unsymmetric axis are derived in Cartesian coordinates rather than in polar coordinates. in which the effect of rotatory inertia is included. Frequencies and mode shapes are computed numerically for parabolic arches with both clamped ends and both hinged ends. Comparisons of natural frequencies between this study and SAP 2000 are made to validate theories and numerical methods developed herein. The convergent efficiency is highly improved under the newly derived differential equations in Cartesian coordinates. The lowest four natural frequency parameters are reported, with and without the rotatory inertia, as functions of three non-dimensional system parameters the rise to chord length ratio. the span length to chord length ratio, and the slenderness ratio. Also typical mode shapes of vibrating arches are presented.

Experimental Analysis of Axial Vibration in Slim-type Optical Disc Drive (슬림형 광 디스크 드라이브의 축방향 진동에 대한 실험적 해석)

  • 박대경;전규찬;이성진;장동섭
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.12 no.11
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    • pp.833-839
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    • 2002
  • As the demand for slim laptops requires low-height optical disc drives, vibration problems of optical disc drives are of great concern. Additionally, with the decrease of a track width and a depth of focus in high density drives, studies on vibration resonance between mechanical parts become more important. From the vibration point of view, the performance of optical disc drives is closely related with the relative displacement between a disc and an objective lens which is controlled by servo mechanism. In other words, to read and write data properly, the relative displacement between an optical disc and an objective lens should be within a certain limit. The relative displacement is dependent on not only an anti-vibration mechanism design but also servo control capability. Good servo controls can make compensation for poor mechanisms, and vice versa. In a usual development process, robustness of the anti-vibration mechanism is always verified with the servo control of an objective lens. Engineers partially modify servo gain margin in case of a data reading error. This modification cannot correct the data reading error occasionally and the mechanism should be redesigned more robustly. Therefore it is necessary to verify a mechanism with respect to the possible servo gain plot. In this study we propose the experimental verification method for anti-vibration mechanism with respect to the existing servo gain plot. Thismethod verifies axial vibration characteristics of optical disc drives on the basis of transmissibility. Using this method, we verified our mechanism and modified the mechanism for better anti-vibration characteristics.

Comparison of basic bodice block for adults women by 3D simulation - focus of the DC Suite Program - (3차원 시뮬레이션을 활용한 성인여성용 길 원형 비교 연구 - DC Suite Program을 중심으로 -)

  • Cha, Sujoung;Kang, Yeonkyung
    • Journal of Fashion Business
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    • v.17 no.2
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    • pp.63-81
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    • 2013
  • A Study using compare and analyze about differences among three patterns(shape and size of pattern, fitting and amount of air gap and so on) through 3D simulation. This study use 3D simulation program, DC Suite version 3.0. The results are as a follows: The results of estimation about total appearance, the pattern of Bunka is best of all pattern about total fitting and silhouette of front and back side. The pattern of armstrong and on&on stand low in estimation. As the total fitting, the pattern of Bunka is 4.40, the pattern of Armstrong is 2.60 and the pattern of On&on is 1.60. The result show better pattern of Bunka than pattern of Armstrong and On&on. When we examine about space between body and cloth, the pattern of Bunka is best. The pattern of Armstrong don't have problems about back side but front side have some problem of getting loose. Because it only have a waist dart so dart size is too big. The pattern of On&on have so much space because it don't have a waist dart. On the amount of air gap, the pattern of Bunka squash up body so it have the amount of air gap 0.08 at bust circumference and underbust circumference. Next is the pattern of Armstrong, amount of air gap is 0.14 at bust circumference and 0.23 at underbust circumference. The pattern of On&on's amount of air gap is 0.30 at bust circumference and 0.37 at underbust circumference. So the pattern of Bunka is bodice block of the best closing adhesion and the On&on is a loose-fitting pattern.

A Study on Zen Fashion in the Point of View of Culture Transition (문화(文化) 전이(轉移)(culture transition)의 시각(視覺)에서 본 젠(禪) 패션 연구(硏究))

  • Park, Hye-Won
    • Journal of Fashion Business
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    • v.4 no.1
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    • pp.73-85
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    • 2000
  • The purpose of this study is for considering about Zen fashion in the point of view of culture transition. Through this research, the Far-East including Korea will be confirmed as a center of fashion culture in 21st century. The contents are the meaning of culture transition in Post Modern period, the meaning of Zen and changing of fashion trend as the background of Zen Fashion, and the characteristics of Zen fashion design. The results are as follows: Anti-western movement or dismantlement of culture has been represented the limitation of western centered culture. So the interesting about East means the changing to east from west in ideas. To make new creation in fashion field, the comprehension about the western fashion which has been preceeded and new trials using the our tradition will be needed. Zen is a kind of Buddhism and the essence of it is to find myself and express individual experiences. The change of one's sens of value, new age movement and concerning of environment and ecology make more comfortable, simple and healthy elements in clothing. The fusion style is under a vogue in life style and Zen is the core of this trend. The characteristics of Zen fashion are flat dismantlement which has been know as a Japanese style, oriental minimalism and nature beauty of ecology. This characteristics are found not only the shape, color but the will of the behind. The pursing temperance and naturalism are represented the fashion culture transition from the West to Far-East. Therefore multi points of fashion research is very important and the identify about Korean fashion is required in lately for new fashion paradigm.

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Evaluations of Swaging Process for Rotor Core of Induction Motors (유도전동기 회전자 제작시 압입작업 평가)

  • Park, Sang-Chul
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.10
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    • pp.21-26
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    • 2016
  • This study evaluates the magnitudes and distributions of contact tangential forces with the swaging depth of punch acting at the contact surfaces between a rotor core slot and a Cu bar during a sequential rotor core swaging process. The effects of the core slot shape on the magnitudes and distributions of the total contact forces were investigated to improve the productivity of the rotor core swaging process. Parametric elastic-plastic numerical analyses were performed using simplified two-dimensional cyclic symmetric plane strain models to evaluate the contact force distributions at the contact surfaces. The numerical analysis results show that the total contact tangential forces increased by about 55% with the adjacent Cu bar swaging process. The length of the core slot is a dominant factor in the core slot design as result of the increased total contact tangential forces during the swaging process of the rotor core.

Development of Prefabricated Voided-Slab Bridge Using PSC-I Girders (프리캐스트 I형 거더를 이용한 조립식 중공슬래브교 개발)

  • Kim, Hyun-Gi
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.6
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    • pp.742-752
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    • 2017
  • The bridge type of steel concrete composite rahmen or pre-flex has been applied where a lower depth girder is required due to vertical clearance restrictions caused by the crossing of rivers and roads. On the other hand, because these types are not only complicated to manufacture and construct, but also expensive, void slab bridges may be an alternative. In this study, prefabricated PSC-I shape girder was used to make a void slab and all procedures for bridge development, such as analysis, design, fabrication, and real-scale test, were included in the scope of research. The results of this study will provide sufficient background data to be applied to the field and the structural safety has been verified through experiments.

Portfolio Decision Model based on the Strategic Adjustment Capacity: A Bionic Perspective on Bird Predation and Firm Competition

  • Mao, Chao;Chen, Shou;Liu, Duan
    • Journal of Distribution Science
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    • v.13 no.1
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    • pp.7-18
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    • 2015
  • Purpose - This study integrates a corporate competition system with a bird predation system to examine how organizational strategic adjustment capacity influences firm performance. By proving the prominent effects on performance, a financial vector is constructed to represent corporate strategic adjustment results, and an operation capacity vector is constructed, which can be categorized as a parameter for locating birds. All these works help us to propose a new method of investment, the portfolio decision model based on the strategic adjustment capacity. Research design, data, and methodology - Strategic adjustment capacity can be decomposed into three aspects: the organizational learning capacity from the top firms, the extent to which firms maintainor rely on the best operational capacity vector in history, and the ability to eliminate the disadvantages or retain the advantages of the operation capacity vector from the previous year. The method of solving cyclic equations is designed to evaluate strategic adjustment. Firms manufacturing specialized equipment are chosen to test the effects of the strategic adjustment capacity on three aspects of firm performance. Results - There is a positive correlation between the capacity to learn from the best firms and performance improvement. The relationship between the dependence or maintenance of a firm's advantages and performance improvement is a U-shape curve, and there is no significant effect of inertial control on performance improvement. Conclusions - A firm's competition system is a sophisticated adaptation, and competitive advantage and performance can be investigated based on the principles of competition in nature.

Effects of Tie Details on Seismic Performance of RC Columns Subjected to Low Compression Loads (낮은 압축력을 받는 철근콘크리트 기둥의 내진성능에 대한 띠철근 상세의 영향)

  • Kim, Chul Goo;Park, Hong Gun;Eom, Tae Sung;Kim, Tae Wan
    • Journal of the Earthquake Engineering Society of Korea
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    • v.19 no.4
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    • pp.195-205
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    • 2015
  • Various non-seismic tie details are frequently used for one- and two-story small buildings because the seismic demand on their deformation capacities is not relatively significant. To evaluate the effects of the non-seismic tie details on the seismic performance of reinforced concrete columns, six square columns with a cross section of $400{\times}400mm$ and six rectangular columns with a cross section of $250{\times}640mm$ were tested. The anchorage details at both ends and spacing of tie hoops, along with the cross-sectional shape and the magnitude of axial load, were considered as the primary test parameters. Test results showed that square columns had higher stiffness and lower lateral deformation rather than rectangular columns. Both lap spliced tie and U-shaped tie provided comparable or improved seismic performance to $90^{\circ}$ hook tie in terms of maximum strength, ductility, and energy dissipation. The predicted curves with modeling parameters in ASCE41-13 were conservative for test results of lap spliced tie and U-shaped tie specimens since plastic behavior after flexural yielding could not be considered. For economical design, ASCE41-13 should be revised with various test results of tie details.

Study on Decision-Making Model to Select Optimal Strengthening Method (최적 보강공법 선정을 위한 의사결정모델에 관한 연구)

  • Sun, Jong-Wan;Park, Kyong-Hoon;Oh, Hong-Sub;Cho, Hyo-Nam
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.14 no.1
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    • pp.117-124
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    • 2010
  • Different to other social infrastructures, bridge elements or bridges can be damaged or collapsed and this may cause death toll and severe social and economical damage, bridges should be managed to maintain a safety level. Diverse strengthening methods is developed to improve a deteriorated bridge performance up to original design level. But rational decision-making process and methodologies to select a optimum strengthening method are absence yet in Korea. This paper therefore derived items and proposed methodologies for quantity estimate considering uncertainty to select a optimum strengthening method among conceptually designed alternatives. And also, to demonstrate the applicability and verification of the proposed approach, it was applied to select the optimum strengthening method for the deteriorated T-shape concrete girder bridge. The model and the procedure can greatly contribute to the uncertainty-oriented alternative selection.

Design of Face Recognition Algorithm based Optimized pRBFNNs Using Three-dimensional Scanner (최적 pRBFNNs 패턴분류기 기반 3차원 스캐너를 이용한 얼굴인식 알고리즘 설계)

  • Ma, Chang-Min;Yoo, Sung-Hoon;Oh, Sung-Kwun
    • Journal of the Korean Institute of Intelligent Systems
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    • v.22 no.6
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    • pp.748-753
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    • 2012
  • In this paper, Face recognition algorithm is designed based on optimized pRBFNNs pattern classifier using three-dimensional scanner. Generally two-dimensional image-based face recognition system enables us to extract the facial features using gray-level of images. The environmental variation parameters such as natural sunlight, artificial light and face pose lead to the deterioration of the performance of the system. In this paper, the proposed face recognition algorithm is designed by using three-dimensional scanner to overcome the drawback of two-dimensional face recognition system. First face shape is scanned using three-dimensional scanner and then the pose of scanned face is converted to front image through pose compensation process. Secondly, data with face depth is extracted using point signature method. Finally, the recognition performance is confirmed by using the optimized pRBFNNs for solving high-dimensional pattern recognition problems.