• 제목/요약/키워드: Material Selection

검색결과 960건 처리시간 0.025초

AHP기법을 이용한 방수공법 선정 평가항목의 가중치 결정에 관한 연구 (A Research for Weight Decision of Waterproofing Methods Selection Evaluation Item using the AHP)

  • 최성민;임종권;오상근;서치호
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2008년도 추계 학술논문 발표대회
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    • pp.205-211
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    • 2008
  • Recently, selects method of waterproofing where is suitable with method and material physical properties, construction technique, Productive technique and specifications and maintenance techniques evaluation for the same evaluation method is coming to be presented. Respects the application which select system is substantial objectively reflects a weight to evaluation item the research for is necessary. This research the evaluation which in order is effective and the decision-making to be possible about technically countermeasures for a quality security from waterproofing materials, method selection processes, clearly responsible dividing of construction and maintenance techniques. A sets weight of evaluation item for right select system, it stratify the causes which affect in priority based on AHP.

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주축 모터 출력 특성에 근거한 무인 선삭 제어 (Unmanned Turning Process Control Based on Spindle-Motor Power Characteristics)

  • 박장호;홍성함;이병휘;허건수
    • 대한기계학회논문집A
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    • 제26권7호
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    • pp.1446-1452
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    • 2002
  • In the turning process, the feed is usually selected by a machining operator considering workpiece, cutting tool and depth of cut. Even if this selection can avoid power saturation or tool breakage, it is usually conservative compared to the capacity of the machine tools and can reduce the productivity significantly. This paper proposes a selection method of the feed and the reference cutting force based on MRR(material removal rate), maximum spindle power and specific energy. In order to estimate and control cutting force accurately in transient and steady state, this study utilizes a synthesized cutting force estimation method and a Fuzzy controller. The experimental results show that these systems can be useful for the unmanned turning process.

작업평가방법론 및 현장 적용 고찰 (A Survey on the Workload Evaluation Methods and Their Applications to WMSD Work in Industries)

  • 박재희
    • 대한인간공학회지
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    • 제29권4호
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    • pp.435-444
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    • 2010
  • To identify and evaluate the risk factors in WMSD work, a number of ergonomic workload evaluation methods have been developed. In the legal examination of WMSD risk factors, simple observational workload evaluation methods are widely used instead of using costly measurement equipments such as EMG and motion analyzer. The simple workload evaluation methods can be categorized into three groups; risk factor checklist methods, posture observation methods, and manual material handling task evaluation methods. In terms of the categories, this survey summarized several representative workload evaluation methods and compared them each other. Then some industrial application cases referring each the workload evaluation methods were surveyed. Due to the characteristics of each method, the selection and application procedure of workload evaluation method should be appropriate for the corresponding work. Therefore, some guidelines for the selection and application procedure of workload evaluation method were suggested.

선삭변수 최적화를 위한 진화 알고리듬 응용 (Turning Parameter Optimization Based on Evolutionary Computation)

  • 이성열;곽규섭
    • 경영과학
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    • 제18권2호
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    • pp.117-124
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    • 2001
  • This paper presents a machining parameter selection approach using an evolutionary computation (EC). In order to perform a successful material cutting process, the engineer is to select suitable machining parameters. Until now, it has been mostly done by the handbook look-up or solving optimization equations which is inconvenient when not in handy. The main thrust of the paper is to provide a handy machining parameter selection approach. The EC is applied to rapidly find optimal machining parameters for the user\\`s specific machining conditions. The EC is basically a combination of genetic a1gorithm and microcanonical stochastic simulated annealing method. The approach is described in detail with an application example. The paper concludes with a discussion on the potential of the proposed approach.

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표준화된 방수기술 평가기법 개발 및 평가체계 구축 (Proposed Development and Evaluation System for Existing Standardized Waterproof Technology Assessment Methods)

  • 송제영;이선규;최은규;이정훈;김병일;오상근
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2018년도 춘계 학술논문 발표대회
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    • pp.341-342
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    • 2018
  • Waterproofing materials and construction methods have been developed and applied to various construction sites since the past. However, there many cases where the waterproofing performance is not satisfactory, leading to continuous water leakage. It has been observed that a key reason for this is because waterproofing method and material selection is not optimized in terms of the appropriate application area and environmental degradation factors. This paper proposes that future selection of waterproofing methods should consider the following evaluation criteria; 1) waterproof performance evaluation according to site conditions, 2) evaluation of construction method, 3) manufacturing and maintenance of waterproofing systems.

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최적 절삭속도및 피이드 선정 전문가 시스템 (Expert System for optimal cutting speed and feed rate selection)

  • 이건범;김연민
    • 산업공학
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    • 제9권1호
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    • pp.1-10
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    • 1996
  • In this study, expert system for the selection of the optimal cutting speed and feed rate was developed using NEXPERT system shell. The NC system has been usually used inefficiently because the input command, which contains cutting speed, feed-rate and the depth of cut, is fixed value which depends on principally operator's experience and machining handbooks providing a guideline for applicable ranges. On the other hand, the optimal cutting conditions vary with time, and depend on tool and machine characteristics, work materials, and cost factor and so on. In this study, if cutting factors, such as, cutting method, material type, cutting depth, and tool nose radius are specified, our expert system gets the information about the standard cutting speed form the cutting speed database, and provides optimum feed rate for these cutting conditions. This cutting speed database can be updated by inputting valid cutting speed which is obtained form the practices.

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회전형상제품의 가공을 위한 컴퓨터 지원 공정계획 시스템 (A Semigenerative Process Planning System for Rotational Parts)

  • 이진수;최후곤
    • 대한산업공학회지
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    • 제19권4호
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    • pp.49-70
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    • 1993
  • The purpose of this study was to develop a semigenerative process planning system for the turning processes required for rotational parts. The system developed in this study showed three major roles for a given part : selection of appropriate turning processes, scheduling of selected processes, and selection of appropriate tools to be used for selected processes. Four information files and six modules were developed to produce a process plan. When geometric features, dimension, tolerance, material types, and surface finish data are inputted to the system, optimal processes, processing sequences, selected tools, and machining costs are to be produced as a process plan.

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Smooth Boundary Topology Optimization Using B-spline and Hole Generation

  • Lee, Soo-Bum;Kwak, Byung-Man;Kim, Il-Yong
    • International Journal of CAD/CAM
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    • 제7권1호
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    • pp.11-20
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    • 2007
  • A topology optimization methodology, named "smooth boundary topology optimization," is proposed to overcome the shortcomings of cell-based methods. Material boundary is represented by B-spline curves and their control points are considered as design variables. The design is improved by either creating a hole or moving control points. To determine which is more beneficial, a selection criterion is defined. Once determined to create a hole, it is represented by a new B-spline and recognized as a new boundary. Because the proposed method deals with the control points of B-spline as design variables, their total number is much smaller than cell-based methods and it ensures smooth boundaries. Differences between our method and level set method are also discussed. It is shown that our method is a natural way of obtaining smooth boundary topology design effectively combining computer graphics technique and design sensitivity analysis.

Preparation of Titanium Microfiltration Membrane by Field-flow Fractionation Deposition

  • Wang, QiangBing;Tang, HuiPing;Zhang, QianCheng;Qiu, QunFeng;Wang, JianYong
    • 한국분말야금학회:학술대회논문집
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    • 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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    • pp.312-313
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    • 2006
  • The primary aim pursued by the preparation of separation membrane is the preparation of the membrane thin as well as with no defect. The field-flow fractionation deposition is a new molding technology which can overcome the traditional disadvantages such as multi-preparation to the preparation of great area of separation membrane with no defect. Therefor the mainly ingredients which influence the appearance and performance of titanium membrane layer are investigated by scanning electricity mirror (SEM) as well as porous material testing instrument: powder performance prepared and confected; selection of supporting body; sintering system such as temperature and time. It is shown that the membrane thickness can be controlled at $50{\mu}m$ or so; the filtration precision mainly rests with powder performance and selection of supporting body and little sintering system

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표준화된 방수기술 평가기법 개발 및 평가체계 구축 (생산기술, 유지관리 평가 중심) (Proposed Development and Evaluation System for Existing Standardized Waterproof Technology Assessment Methods(Production technology, maintenance evaluation))

  • 송제영;서현재;최은규;이정훈;김병일;오상근
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2019년도 추계 학술논문 발표대회
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    • pp.235-236
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    • 2019
  • Waterproofing materials and construction methods have been developed and applied to various construction sites since the past. However, there many cases where the waterproofing performance is not satisfactory, leading to continuous water leakage. It has been observed that a key reason for this is because waterproofing method and material selection is not optimized in terms of the appropriate application area and environmental degradation factors. This paper proposes that future selection of waterproofing methods should consider the following evaluation criteria; 1) waterproof performance evaluation according to site conditions, 2) evaluation of construction method, 3) manufacturing and maintenance of waterproofing systems.

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