• Title/Summary/Keyword: Computer Aided process planning

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An Integrated AHP-VIKOR Methodology for Facility Layout Design

  • Shokri, Hamidreza;Ashjari, Behzad;Saberi, Morteza;Yoon, Jin Hee
    • Industrial Engineering and Management Systems
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    • v.12 no.4
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    • pp.389-405
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    • 2013
  • A facility layout design (FLD) problem can be generally introduced as assignment of facilities (departments) to a site such that a set of criteria are satisfied or some objectives are minimized (maximized). Hence, it can be considered as a multi-criteria problem due to the presence of qualitative criteria such as maintenance or flexibility and quantitative criteria such as the total cost of handling material. The VIKOR method was developed to solve multiple criteria decision making problems with conflicting and non-commensurable (different units) criteria, assuming that compromising is acceptable for conflict resolution, the decision maker wants a solution that is the closest to the ideal, and the alternatives are evaluated according to all established criteria. This paper proposes a hierarchical analytic hierarchy process (AHP) and VIKOR approach to solve the FLD problem. A computer-aided layout-planning tool is adopted to generate the facility layout problems, as well as their quantitative data. The qualitative performance measures are weighted by AHP. VIKOR is then used to solve the FLD problem. Finally, the proposed integrated procedure is applied to three real-time examples.

Automatic Offline Teaching of Robots for Ship Block Welding Applications (선체 블록 용접을 위한 효과적 로봇 오프-라인 자동교시 소프트웨어 개발 연구)

  • Lim, Seang Gi;Choi, Jae Sung;Hong, Sok Kwan;Han, Yong Seop;Borm, Jin Hwan
    • Journal of the Korean Society for Precision Engineering
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    • v.14 no.5
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    • pp.42-52
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    • 1997
  • Computer aided process planning and Offline programming are decisive factors in successful implementation of automated robotic production. However, conventional offline programming procedure has proven ineffective due to time-consuming teaching process for robot programming and due to inefficient system modeling. The paper presents an efficient procedure to semi-automatically generate robot job programs for ship block welding applications. In the research, the teaching positions are automatically determined by predefined rules which are functions of the type and the dimensions of the given welding section of ship block. And a sequence of robot movements and welding conditions such as welding type, welding current, welding speed, and welding torch orientation, are determined by use of Standard Program which is experimentally proved to work well for the welding wection group. Finally, a robot program for the welding section is generated automatically. Based on the algorithm, a offline automatic teaching software is developed. The paper presents also the algorithm and structure of the software.

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A Study on the Computer­Aided Processing of Sentence­Logic Rule (문장논리규칙의 컴퓨터프로세싱을 위한 연구)

  • Kum, Kyo-young;Kim, Jeong-mi
    • Journal of Korean Philosophical Society
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    • v.139
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    • pp.1-21
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    • 2016
  • To quickly and accurately grasp the consistency and the true/false of sentence description, we may require the help of a computer. It is thus necessary to research and quickly and accurately grasp the consistency and the true/false of sentence description by computer processing techniques. This requires research and planning for the whole study, namely a plan for the necessary tables and those of processing, and development of the table of the five logic rules. In future research, it will be necessary to create and develop the table of ten basic inference rules and the eleven kinds of derived inference rules, and it will be necessary to build a DB of those tables and the computer processing of sentence logic using server programming JSP and client programming JAVA over its foundation. In this paper we present the overall research plan in referring to the logic operation table, dividing the logic and inference rules, and preparing the listed process sequentially by dividing the combination of their use. These jobs are shown as a variable table and a symbol table, and in subsequent studies, will input a processing table and will perform the utilization of server programming JSP, client programming JAVA in the construction of subject/predicate part activated DB, and will prove the true/false of a sentence. In considering the table prepared in chapter 2 as a guide, chapter 3 shows the creation and development of the table of the five logic rules, i.e, The Rule of Double Negation, De Morgan's Rule, The Commutative Rule, The Associative Rule, and The Distributive Rule. These five logic rules are used in Propositional Calculus, Sentential Logic Calculus, and Statement Logic Calculus for sentence logic.

Study on the Ship Structure Design and Modeling Methods for CIM (조선 CIM 구축을 위한 구조설계 및 모델링 방법에 관한 연구)

  • Yoon, D.Y.;Suh, H.W.;Kim, H.C.;Lim, H.K.;Choi, H.S.
    • Journal of the Society of Naval Architects of Korea
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    • v.33 no.1
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    • pp.173-181
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    • 1996
  • In this paper, we studied the modeling methods of initial ship structure design results using ship structure product model for concurrent engineering in shipbuilding industry. We suggested two modeling methods which are programming method using CAD commands and Macros for primary structure members. Also, we investigated three modeling procedures which are modeling procedure in unit concept, modeling procedure using version control, and modeling procedure for computer aided process planning. We demonstrated how to use the structure product modeling results in some application fields. Finally, we proposed some ideas for future research.

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The Digital Mock-Up Information System for New Car Development

  • Min, Sung-Ki;Lee, Chul-Woo
    • Proceedings of the CALSEC Conference
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    • 1999.07a
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    • pp.277-299
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    • 1999
  • Since Chrysler Motor Co. had experienced the digital development system in the beginning of 1990's, most of leading automobile companies are trying to apply a digital information system for their own business process reengineering based upon concurrent engineering system from product planning phase. This is called as virtual DMU(Digital Mock-Up) system instead of the traditional PMU(Physical Mock-Up) system. By using the virtual prototype, all of the design requirements and system specifications can be checked, changed and optimized more quickly and more efficiently. This paper consists of five chapters for the DMU information system. In the 1$^{st}$ chapter, the principle of digital design system is suggested by using four basic modules such as product design module, process design module, manufacturing system design module and central control module. The basic scheme of DMU is introduced with the benefits of application in the chapter 2. In the chapter 3, a digital design process of new car development is explained with the detailed DMU design and design review processes. In the chapter 4, the practical DMU manufacturing techniques and applications are introduced as CAD/CAM analyses, DPA(Digital Pre-Assembly)reviews for development, production, operation and maintenance phases, digital tolerance analyses and digital factory analyses for assembling line simulation, automated robot welding processes, production jig & fixtures and painting process simulation. Finally, the activities of digital design support; CAS-styling, CAE-engineering and CAT-testing are summarized for design optimization in the chapter 5. As today's automobile manufactures and related business organizations are struggling to compete in the global marketplace, they are concentrating on efficient use of DMU information system to reduce the new car development cost, to have shorten the delivery schedule and to improve product design quality. To meet the demand of those automobile industries on digital information systems, the CALS(Computer aided Acquisition and Logistics Support) and EC(Electronic Commerce)initiative has been focused as a dominant philosophy in defense & commercial industries, specially automobile industries.s.

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An Automated Nesting and Process Planning System of Irregularly Shaped-Sheet Metal Product With Bending and Piercing Operation for Progressive Working (굽힘 및 피어싱 공정을 갖는 불규칙형상 제품의 프로그레시브 가공을 위한 네스팅 및 공정설계 자동화 시스템)

  • Choi, Jae-Chan;Kim, Byung-Min;Kim, Chul
    • Journal of the Korean Society for Precision Engineering
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    • v.15 no.6
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    • pp.22-32
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    • 1998
  • This paper describes a research work of developing a computer-aided design of irregularly shaped-sheet metal product with bending and piercing operation for progressive working. An approach to the CAD system is based on the knowledge-based rules. Knowledge for the CAD 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 with a personal computer and is composed of five main modules, which are input and shape treatment, flat pattern-layout, production feasibility check, blank-layout, and strip-layout module. Based on knowledge-based rules, the system is designed by considering several factors, such as radius and angle of bend, material and thickness of product, complexities of blank geometry and punch profile, and availability of press. This system is capable of unfolding a formed sheet metal part to give flat pattern and automatically account for the adjustment of bend allowances to match tooling requirements by checking dimensions and the best utilization ratio of blank-layout within bending production feasibility area which is beyond ${\pm}30^{\circ}$ degrees intersecting angle between grain flow and bending edge line and which is suitable to progressive bending operation. Also the strip-layout drawing generated by a bending and a piercing operation according to punch profiles divided into automatically for external area of irregularly shaped-sheet metal product is displayed in graphic forms.

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A Development of CNC Engraving Machine System for Non-experts (비숙련자를 위한 CNC 조각기 시스템의 개발 방안 연구)

  • Yang, Min Cheol;Chung, Yunchan
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.41 no.7
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    • pp.673-682
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    • 2017
  • As the culture of making things based on "do-it-yourself" (DIY) activity is increasingly promoted, the use of recent digital technologies and tools, including the 3D printer, have become widespread. However, the use of computerized numerical control (CNC) engraving machine is considered difficult because of the complicated procedures and specialized knowledge required for its operation. Therefore, this study aims to resolve the issue that limits the usability of the CNC engraving machine. This paper presents a novel CNC engraving machine system for non-experts based on human-centered design. First, the size and type of the workpiece and tool are reduced. Second, computer-aided process planning (CAPP) steps such as tool path generation, workpiece clamping, and corresponding coordinate system are automated by compromising productivity and efficiency. As a result, a CNC engraving machine system that can be easily used by non-experts was developed. This development has great significance in that it opens up the possibility of using the CNC engraving machine for a wider range of DIY activities.