• Title/Summary/Keyword: flat-shaped

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A CAD/CAM System for Blanking or Piercing of Irregular Shaped-Sheet Metal Products (불규칙형상 박판제품의 블랭킹 및 피어싱용 CAD/CAM 시스템)

  • 최재찬;김철;박상봉
    • Journal of the Korean Society for Precision Engineering
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    • v.15 no.8
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    • pp.174-182
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    • 1998
  • This paper describes a research work of developing a computer-aided design and machining of irregular shaped-sheet metal product for blanking or piercing operation. An approach to the CAD/CAM system is based on the knowledge-based rules. Knowledge for the CAD/CAM system is formulated from plasticity theories, experimental results and the empirical knowledge of field experts. The system has been written in AutoLISP on the AutoCAD and in customer tool kit on the SmartCAM with a personal computer and is composed of nine modules, which are input and shape treatment, flat pattern-layout, production feasibility check, blank-layout, strip-layout, die-layout, data conversion, modelling, and post-processor module. Based on knowledge-based rules, the system is designed by considering several factors, such as material and thickness of product, complexities of blank geometry and punch profile, diameter and material of a wire, and availability of press. This system is capable of generating NC data automatically according to drawings of die-layout module. Results which are carried out in each module will provide efficiencies to the designer and the manufacturer of blanking or piercing die in this field.

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A Study of Architectural Core Planning for Plan Types of General Hospital Wards (국내 종합병원 병동부 평면 유형에 따른 코어 연구)

  • Lee, Hyunjin;Park, Jaeseung
    • Journal of The Korea Institute of Healthcare Architecture
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    • v.18 no.3
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    • pp.41-49
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    • 2012
  • Most large-sized and tall-risen general hospitals of today fairly depend on in-patient wards in designing hospital styles. The core planning for the efficient movements of various people in the words should take into account the sustainable connections between/among the floors, as well as hospital structures and mechanical functions. This study sampled for the study 19 hospital in-patient wards and investigated their flat-core styles. It was found out that hospital structures are changing from symmetrical styles of triangles, quadrangles and rectangles through bending, configuring, transforming to efficient new styles. Symmetrically quadrangled flat-styles are made of multi-cores spread with main an sub-cores. In contrast, symmetrically triangled flat-styles place the open place in the middle in order to prevent from its deepening, and widened the depth line through changing the outdoor top point. Non-symmetrical rectangles minimized the depth value to maintain the recent styles used in the wards, and tended to prefer the transformed styles of quadrangles. The double-corridors easily transshaped from mono corridors reveals the triangled, W-shaped, or Y-shaped figures. The site area ratio of the cores is 11.95% in average. The number of beds which one elevator covers is 66.51 beds in average, and the size of site area which one elevator covers 216.68m. Most cores on the base floor clustered around the average value, with more than 1000 beds shoes 12.83%, does 12.93%, does 14.64%, does 14.58%, which says that the core ratio increases according to hospital beds.

The Prototype Development of Clothing for Pet Dogs (애완견 의류의 원형 개발)

  • Kim, Jung-Min;Park, Sun-Kyung
    • The Research Journal of the Costume Culture
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    • v.18 no.4
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    • pp.599-611
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    • 2010
  • The purpose of this study is to develop the most appropriate garment patterns for dog. This study is analyzed the body structures and bodily movements of different types of dogs and constructed garment patterns that are appropriate for each category: the basic pattern for dogs with oval-shaped chests; and the modified pattern for the ones with barrel-shaped chests. Analyzing some of the existing patterns in the market as well as studying the size chart of one of the dog apparel manufacturers, who participated in the Fashion Week for the very first time, were undertaken in order to understand the bodily figures and movements of dogs. Furthermore, based the previous studies and relevant information available regarding some of the most popular dogs in four selected countries: (names of the selected countries), dogs were broadly categorized into three groups according to the shape of their chests: Oval, Barrel, and Flat-sided. Later, two types of pattern were created and then constructed for fitting: the basic pattern for oval-shaped chest; and the modified pattern for barrel-shaped chest. As a result, the two patterns turned out to be most suitable for pet dogs.

A Study on a Planar Array Antenna Design with a Flat-Topped Radiation Pattern (구형 방사 패턴을 갖는 평면 배열 안테나 설계에 대한 연구)

  • Eom Soon-Young;Pyo Cheol-Sig;Jeon Soon-Ick;Kim Chang-Joo
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.15 no.9
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    • pp.896-905
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    • 2004
  • In this paper, the design, fabrication and experiment on a planar array antenna with a flat-topped radiation pattern for a mobile base station antenna were described. The current distribution of an antenna aperture, which is easily realizable in a feeding network compared with the conventional one of sin(x)/x was optimized for shaping a desired flat-topped radiation pattern. The planar array antenna designed in this paper has a rectangular lattice and is composed of array elements of 16${\times}$8. Each radiating element, which is a microstrip element fed coaxially, has a linear vertical polarization and the feed network which use a Wilkinson power divider and a 180$^{\circ}$ ring hybrid coupler as a base element is designed. The flat-topped radiation pattern with 90$^{\circ}$ is shaped by 16 array elements with the element spacing of 0.55 λ$_{ο}$ in the azimuth plane, and the normal radiation pattern with 10$^{\circ}$ is shaped by 8 array elements with the element spacing of 0.65 λ$_{ο}$ in the elevation plane. Also, the planar array antenna is symmetrically divided into four parts. It consists of one hundred-twenty-eight radiating elements, thirty-two 1-4 column dividers, low 1-8 row dividers and one 1-4 input power divider. In order to verify electrical performances of the planar way antenna proposed in this paper, the experimental breadboard operated in tile band of 1.92~2.17 GHz(IMT2000 band) was fabricated, and its experimental results were a good agreement with simulation ones.

A Study on the Daylighting Transmittance Efficacies of Skylights by Calculating the Effective Transmittance of Light Well (광정의 유효투과율에 의한 천창 형태별 주광의 투과효율 평가)

  • Kim, Chang-Sung
    • KIEAE Journal
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    • v.12 no.2
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    • pp.53-58
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    • 2012
  • Daylight is one of the most critical factors that can be utilized for architectural spaces; compared to artificial light, it is a sustainable energy source without the cost of electric energy and offers a more natural feeling to the visitors in the building. To make the space quality better, many architects have tried to predict daylight performance during the design process. The aim of this study is to evaluate the daylight transmittance efficacies of the five shapes - Flat, Pyramid, Dome, Barrel Vault. Ridge - of skylights. The results of this study indicated that the differences of transmittance efficiency among various skylights were less than 4.6% except the flat shaped skylight. Therefore, this study shows that there were no big differences of the daylight transmittance efficacies among the shapes of skylights.

Scanning Electron Microscopic Study of the Sertoli Cell Processes in the Rat (쥐 Sertoli 세포돌기의 주사전자현미경적 연구)

  • 박영석;이성호;권건오
    • Korean Journal of Animal Reproduction
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    • v.22 no.3
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    • pp.245-252
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    • 1998
  • The three-dimensional structure of the Sertoli cell in the rat was investigated by scanning electron microscopy. Morphologically, seven types of Sertoli cell processes were evident : Shrot, flat and ramified processes are projected from the lateral side of the basal portion of Sertoli cell. Leaf-like processes are attached to the surface of spermatocytes and spermatids. Slender cord-like processes, flat and irregular shaped processes, sucker-like processes and club-like processes are observated in the middle and apical portion of seminiferous epithelium. The sheet-like processes rest upon more than one-thirds of the surface of each spermatogonium, spermatocyes and spermatids located in the proximity of the Sertoli cell. All Sertoli processes are originated from Sertoli cell column. Just before spermiation, the processes which are attached to the head of maturation spermatid are eliminated. Though the mechanism for elimination of residual body is not known, these observations segget that the Sertoli cell process are thought to have a reciprocity with the germ cells.

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Preliminary Design Analysis of Low Speed Interior Permanent Magnet Machine with Distributed and Concentrated Windings

  • Ahsanullah, Kazi;Dutta, Rukmi;Rahman, M.F.
    • Journal of international Conference on Electrical Machines and Systems
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    • v.3 no.2
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    • pp.139-147
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    • 2014
  • The paper presents a systematic comparison of four topologies of the interior permanent magnet machine (IPMM) designed for low speed applications. This comparative study investigates the suitability of the concentrated winding and distributed winding in the stator and the flat-shaped or V-shaped magnets in the rotor poles. The paper also studies the inductance characteristics of the designs using finite element analysis. Various steps taken to minimize the cogging torque and torque ripple in the studied machines were also discussed in details.

Effects of Change of Wafer Shape through Heating on Chemical Mechanical Polishing Process (가열에 의한 웨이퍼 형상 변화가 CMP에 미치는 영향)

  • 권대희;김형재;정해도
    • Journal of the Korean Society for Precision Engineering
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    • v.20 no.1
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    • pp.85-90
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    • 2003
  • Removal rate and Within Wafer Non-Uniformity (WIWNU), the most critical issues in Chemical Mechanical Polish (CMP) process, are related to the pressure distribution, wafer shape, slurry flow, mechanical property of pad and etc. Among them, wafer warp generated by other various manufacturing process of wafer may induce the deviation of pressure distribution on the backside of wafer. In the convex shaped wafer the pressure onto the backside of wafer is higher than that of perfectly flat shaped wafer. Besides, such an added pressure is in proportion to the curvature of wafer. That is, the bigger the curvature of wafer becomes the higher the removal rate goes. And the WIWNU is known to be directly related to the pressure distribution on the wafer as well. In other words, the deviation of pressure distribution is in proportion to the WIWNU. In this paper, it is found that the wafer shape may be modified through heating the backside of it and thus properly changed pressure onto the backside of it may improve the WIWNU.

A New Model for Predicting Width Spread in a Roughing Mill - Part I: Application to Dog-bone Shaped Inlet Cross (조압연 공정의 판 폭 퍼짐 예측 모델 - Part I : 도그 본 형상에 적용)

  • Lee, D.H.;Lee, K.B.;Hwang, S.M.
    • Transactions of Materials Processing
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    • v.23 no.3
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    • pp.139-144
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    • 2014
  • In the current study, we present a new model for predicting width spread of a slab with a dog-bone shaped cross section during rolling in the roughing train of a hot strip mill. The approach is based on the extremum principle for a rigid plastic material and a three dimensional admissible velocity field. The upper bound theorem is used for calculating the width spread of the slab. The prediction accuracy of the proposed model is examined through comparison with the predictions from 3-D finite element (FE) process simulations.

A Progressive Automated-Process Planning and Die Design and Working System for Blanking or Piercing and Bending of Sheet Metal Product (박판제품의 블랭킹 및 피어싱과 굽힘 가공을 위한 순차이송용 공정 및 금형 설계와 가공자동화 시스템)

  • Choe, Jae-Chan;Kim, Chul
    • Transactions of Materials Processing
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    • v.7 no.3
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    • pp.246-259
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    • 1998
  • This paper describes a research work of developing a computer-aided design and manufacturing of irregular shaped sheet metal product for blanking or piercing and bending operations. An approach to the system is based on the knowledge-based rules. Knowledge for the system is formulated from plasticity theories experimental results and the empirical knowledge of field experts, This system has been written in AutoLISp on the AutoCAD and in customer tool kit on the SmartCAM with a personal computer and is composed of nine modules which are input and shape treatment, flat pattern-layout, pro-processor module. Based on the knowledge-based rules, the system is designed by considering several factors, such as material and thickness of product complexities of blank geometry and punch profile sheet metal to give flat pattern and automatically account for the adjustment of bending allowances to match tooling requirements by checking dimensions and generating NC data automatically according to drawings of die-layout module. Results carried out in each module will provide efficiencies to the designer and the manufacturer of blanking or piercing and bending die in this field.

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