• Title/Summary/Keyword: process planning selection

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A Hierarchical Expert System for Process Planning and Material Selection (공정계획과 재료선정의 동시적 해결을 위한 계층구조 전문가시스템)

  • 권순범;이영봉;이재규
    • Journal of Intelligence and Information Systems
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    • v.6 no.2
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    • pp.29-40
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    • 2000
  • Process planning (selection and ordering of processes) and material selection for product manufacturing are two key things determined before taking full-scale manufacturing. Knowledge on product design. material characteristics, processes, time and cost all-together are mutually related and should be considered concurrently. Due to the complexity of problem, human experts have got only one of the feasilbe solutions with their field knowledge and experiences. We propose a hierarchical expert system framework of knowledge representation and reasoning in order to overcome the complexity. Manufacturing processes have inherently hierarchical relationships, from top level processes to bottom level operation processes. Process plan of one level is posted in process blackboard and used for lower level process planning. Process information on blackboard is also used to adjust the process plan in order to resolve the dead-end or inconsistency situation during reasoning. Decision variables for process, material, tool, time and cost are represented as object frames, and their relationships are represented as constraints and rules. Constraints are for relationship among variables such as compatibility, numerical inequality etc. Rules are for causal relationships among variables to reflect human expert\`s knowledge such as process precedence. CRSP(Constraint and Rule Satisfaction Problem) approach is adopted in order to obtain solution to satisfy both constraints and rules. The trade-off procedure gives user chances to see the impact of change of important variables such as material, cost, time and helps to determine the preferred solution. We developed the prototype system using visual C++ MFC, UNIK, and UNlK-CRSP on PC.

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An Optimal Tool Selection Method for Pocket Machining (포켓형상가공을 위한 최적공구 선정방법)

  • Kyoung, Young-Min;Cho, Kyu-Kab;Jun, Cah-Soo
    • Journal of the Korean Society for Precision Engineering
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    • v.14 no.7
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    • pp.49-58
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    • 1997
  • In process planning for pocket machining, the selection of tool size, tool path, overlap distance, and the calculation of machining time are very important factors to obtain the optimal process planning result. Among those factors, the tool size is the most important one because the others depend on tool size. And also, it is not easy to determine the optimal tool size even though the shape of pocket is simple. Therefore, the optimal selection of tool size is the most essential task in process planning for machining a pocket. This paper presents a method for selecting optimal toos in pocket machining. The branch and bound method is applied to select the optimal tools which minimize the machining time by using the range of feasible tools and the breadth-first search.

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A Genetic Algorithm A, pp.oach for Process Plan Selection on the CAPP (CAPP에서 공정계획 선정을 위한 유전 알고리즘 접근)

  • 문치웅;김형수;이상준
    • Journal of Intelligence and Information Systems
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    • v.4 no.1
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    • pp.1-10
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    • 1998
  • Process planning is a very complex task and requires the dynamic informatioon of shop foor and market situations. Process plan selection is one of the main problems in the process planning. In this paper, we propose a new process plan selection model considering operation flexibility for the computer aided process planing. The model is formulated as a 0-1 integer programming considering realistic shop factors such as production volume, machining time, machine capacity, transportation time and capacity of tractors such as production volume, machining time, machine capacity, transportation time capacity of transfer device. The objective of the model is to minimize the sum of the processing and transportation time for all parts. A genetic algorithm a, pp.oach is developed to solve the model. The efficiency of the proposed a, pp.oach is verified with numerical examples.

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Integration of process planning and scheduling using simulation based genetic algorithms

  • Min, Sung-Han;Lee, Hong-Chul
    • Proceedings of the Korea Society for Simulation Conference
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    • 1998.10a
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    • pp.199-203
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    • 1998
  • Process planning and scheduling are traditionally regarded as separate tasks performed sequentially. But if two tasks are performed concurrently, greater performance can be achieved. In this study, we propose new approach to integration of process planning and scheduling. We propose new process planning combinations selection method using simulation based genetic algorithms. Computational experiments show that proposed method yield better performance when compared with existing methods.

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Automated initial process planning system for three-axis NC machining of sculptured surfaces (자유 곡면의 3축 NC 가공을 위한 초기 공정 계획 기능의 자동화)

  • Kang, Jae-Kwan
    • Journal of the Korean Society for Precision Engineering
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    • v.14 no.3
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    • pp.114-121
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    • 1997
  • In this paper, the automated initial process planning for 3-axis NC machining of sculptured surfaces is persented. The solution algorithms determining three process planning functions, i.e. machining feasibility, setup orientation and feasible machine selection are developed. The machining feasibility is determined by means of BSM(Binary Spherical Map) which derives its solution quickly in algebraic form, and the setup orientation is determined so that the cutting force is minimized. Finally, the feasible machine is determined by computing the minimum motion ranges of each control axisl. The developed algorithms are tested by numerical simulations, convincing they can by readily implemented on the CAD/CAM system as a process planner.

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A Study on R&D Project Planning Selection Evaluation Indicators based on CIPP model (CIPP모형을 활용한 R&D과제기획 선정평가 도구 개발 연구 : K연구원 중심으로)

  • Hyun-Ku Min
    • Journal of Technology Innovation
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    • v.31 no.3
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    • pp.171-199
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    • 2023
  • The purpose of this study was to develop an evaluation tool for selecting new projects for R&D project planning level of K Research Institute. For this purpose, items and questions for R&D project selection evaluation were developed based on the CIPP model and previous studies on selection evaluation and evaluation indicators for research project evaluation, and then two Delphi surveys were conducted. The developed evaluation tool was surveyed by 13 experts to verify contents validity ratio, convergence and consensus. The finally selected evaluation tool for R&D project planning consisted of 21 questions in 8 items, including 5 questions for context evaluation, 2 questions for input evaluation, 8 questions for process evaluation, and 6 questions for product evaluation. The evaluation tool developed will contribute to the solution of problems in the bottom-up planning process and to the improvement of the planning competence of the researchers. It will also contribute to improve the consistency and efficiency of evaluation during the selection process.

Application of Parameters-Free Adaptive Clonal Selection in Optimization of Construction Site Utilization Planning

  • Wang, Xi;Deshpande, Abhijeet S.;Dadi, Gabriel B.
    • Journal of Construction Engineering and Project Management
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    • v.7 no.2
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    • pp.1-10
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    • 2017
  • The Clonal Selection Algorithm (CSA) is an algorithm inspired by the human immune system mechanism. In CSA, several parameters needs to be optimized by large amount of sensitivity analysis for the optimal results. They limit the accuracy of the results due to the uncertainty and subjectivity. Adaptive Clonal Selection (ACS), a modified version of CSA, is developed as an algorithm without controls by pre-defined parameters in terms of selection process and mutation strength. In this paper, we discuss the ACS in detail and present its implementation in construction site utilization planning (CSUP). When applied to a developed model published in research literature, it proves that the ACS are capable of searching the optimal layout of temporary facilities on construction site based on the result of objective function, especially when the parameterization process is considered. Although the ACS still needs some improvements, obtaining a promising result when working on a same case study computed by Genetic Algorithm and Electimze algorithm prove its potential in solving more complex construction optimization problems in the future.

A Comparative Study by Subject on the New R&D Planning Process (신규 R&D 기획 프로세스에 관한 주체별 비교연구)

  • Bae, Junhee;Park, Jungkyu
    • Economic and Environmental Geology
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    • v.52 no.3
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    • pp.243-250
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    • 2019
  • The purpose of this study is to pro-actively respond to changes in government R&D policy and start to supplement the limitations of previous KIGAM R&D planning process. We looked out through the existing literature for a variety of R&D planning process, and analyzed the R&D planning process characteristics of each institution through the interview. As a result, we can be derived conclusions and implications from three sides, environmental analysis, demand excavation methods, R&D project configuration and selection method. In the case of environmental analysis and the overall need to enhance the skills and mega trend analysis by market trend analysis. And in the demand side, the institute need to establish challenging and specific R&D goals. In addition, in case of configuration and selection of R&D projects we derived several implications, such as convergence, SME support, resource analysis, selection of long-term project.

Integrated Manufacturing Process Design by Applying Concurrent Engineering Principle (동시공학 원리를 적용한 통합 제작공정 설계)

  • 이희각;김태정;김충관
    • Journal of the Korea Institute of Military Science and Technology
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    • v.2 no.2
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    • pp.13-23
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    • 1999
  • This paper deals with manufacturing process design of a simplified gun tube applying CE principle. A concept and characteristics of CE, mathematical model for understanding interaction between design and manufacturing, basic elements and related equations for process planning and cost estimating are introduced. A Knowledge-based Computer-Aided Process Planning System(KCAPPS) is constructed, yielding optimal production cost/time for the shape input and selection of appropriate machines and tools.

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Genetic Algorithm for Integrated Process Sequence and Machine Selection (통합적인 공정순서와 가공기계 선정을 위한 유전 알고리즘)

  • 문치웅;서윤호;이영해;최경현
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 2000.04a
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    • pp.405-408
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    • 2000
  • The objective of this paper is to develop a model to integrate process planning and resource planning through analysis of the machine tool selection and operations sequencing problem. The model is formulated as a travelling salesman problem with precedence relations. To solve our model, we also propose an efficient genetic algorithm based on topological sort concept.

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