• 한국정밀공학회지
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• 제11권6호
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• pp.28-41
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• 1994

An efficient algorithm is proposed to select the proper tools and generate their paths for NC rough cutting of dies and molds with sculptured surfaces. Even though a milling process consists of roughing, semi-finishing, and finishing, most material is removed by a rough cutting process. Therfore it can be said that the rough cutting process occupy an important portion of the NC milling process, and accordingly, an efficient rough cutting method contributes to an efficient milling process. In order work, the following basic assumption is accepted for the efficient machining. That is, to machine a region bounded by a profile, larger tools should be used in the far inside and the region adjacent to relatively simple portion of the boundary while smaller tools are used in the regions adjacent to the relatively complex protion. Thus the tools are selected based on the complexity of the boundary profile adjacent to the region to be machined. An index called cutting path ratio is proposed in this work as a measure of the relative complexity of the profile with respect to a tool diameter. Once the tools are selected, their tool paths are calculated starting from the largest to the smallest tool.

• 한국도로학회논문집
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• 제16권5호
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• pp.109-119
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• 2014

PURPOSES : The control delay in seconds per vehicle is the most important traffic operational index to evaluate the level of service of signalized intersections. Thus, it is very critical to calculate accurate control delay because it is used as a basic quantitative evidence for decision makings regarding to investments on traffic facilities. The control delay consists of time-in-queue delay, acceleration delay, and deceleration delay so that it is technically difficult to directly measure it from fields. Thus, diverse analysis tools, including CORSIM, SYNCHRO, T7F, VISTRO, etc. have been utilized so far. However, each analysis tool may use a unique methodology in calculating control delays. Therefore, the estimated values of control delays may be different by the selection of an analysis tool, which has provided difficulties to traffic engineers in making solid judgments. METHODS : This study was initiated to verify the feasibility of diverse analysis tools, including HCM methodology, CORSIM, SYNCHRO, T7F, VISTRO, in calculating control delays by comparing estimated control delays with that measured from a field. RESULTS : As a result, the selected tools produced quite different values of control delay. In addition, the control delay value estimated using a calibrated CORSIM model was closest to that measured from the field. CONCLUSIONS : First, through the in-depth experiment, it was explicitly verified that the estimated values of control delay may depend on the selection of an analysis tool. Second, among the diverse tools, the value of control delay estimated using the calibrated microscopic traffic simulation model was most close to that measured from the field. Conclusively, analysts should take into account the variability of control delay values according to the selection of a tool in the case of signalized intersection analysis.

• 대한안전경영과학회지
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• 제7권1호
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• pp.57-76
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• 2005

A standardized ergonomics kit is suggested to evaluate and reduce musculoskeletal hazards that yield large socioeconomic burdens in the work system. This kit comprises basic and detailed analysis tools with proper tool selection rules. The basic tool includes a checklist for various risk factors to screen potentially hazardous jobs among manual works. Selective detailed analysis tools can then be applied to the screened job lists for more quantitative and precise evaluation. The tool selection rules are devised for using the basic and detailed analysis tools in a mutually supplemental way. To validate the standardized ergonomics kit, it was applied to evaluate jobs related to the musculoskeletal hazards in a paper-making industry. Among 101 manual jobs investigated, 44 potential hazardous jobs were screened during basic investigation phase and finally 16 hazardous jobs were identified by the detailed analysis phase. The result provided fairly promising ideas of ergonomic interventions for the hazardous jobs.

• 한국과학교육학회지
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• 제13권2호
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• pp.172-186
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• 1993

This stady was carried out to define Gifted student for science, model for selection, the tools and methods and related theory for the selection of the Gifted students for the science in primary school level. Also the developed tools and materials are applied to student and analysed the results to generalize the methods for the selection of Gifted students for science. The definition of Gifted students for science was carried out by the three-ring conception model by Renzulli(1982) and Lee long-Sung which defined the characteristics as three parts such as above average ability, creativity and tesk comitment. The Gifted students for science upper 2 percent which have three characteristics at the same times, namely overlapping three characteristics. The model for the selection of Gifted students consist of four step; such as screeing, selection,differentiation, judgement. The materials for the selection are input at each stage, analysed the results and standard for the selection are made. In the first stage screening, 202 students are selected from the 5060 of 4th and 5th graders according to their achievment, intellecture ability and observation of students activity. In second selection and third differentiation stage, 65 students are seletted according to their achievement In this study it is approved that the Gifted students in science have to be selection by various test such as achievement, intellectual ability, aptitude in science, inquiry activity, manual skill etc, rather rather then simple test such as achievement and intellecture ability. Also it is important to select upper 2 percent who have general abilites overlapping three characteristics mentioned in definition of Gifted students in science and selections model

• 한국통신학회논문지
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• 제34권8C호
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• pp.790-800
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• 2009

H.264/AVC 부호화 표준은 부호화 효율을 높이기 위해 1/4 화소 단위의 움직임 추정, 다중 참조 프레임, 인트라 예측, 루프 필터, 다양한 블록 크기의 지원 등과 같은 새로운 부호화 도구들을 사용한다. 이를 통해 이전의 비디오 부호화 표준들에 비해 율-왜곡(率-歪曲) 관점에서 높은 성능을 보이지만 그로 인해 부호기의 복잡도는 크게 증가하였다. 본 논문은 부호기 복잡도의 증가를 초래하는 주요 부호화 도구들 중 인트라 매크로블록 모드 선택의 복잡도 감소에 주안(主眼)점을 두며, 이에 대한 복잡도 감소 알고리즘을 제시한다. 고속 인트라 모드 선택을 위한 제안하는 방법은 변환 영역에서 에지 활동도를 산출효과 이를 이용하여 intra4x4 및 색차블록에 대한 예측모드를 고속으로 선택함으로써 H.264/AVC 인트라프레임에 대한 고속 부호화를 수행한다. 실험 결과 제안하는 알고리즘은 참조소프트웨어와 비교하여 QCIF 및 CIF 영상에 대해서 각각 59.76% 및 65.03%의 속도향상을 가져오는 반면 비트율 증가 및 PSNR 감소는 매우 미미한 것으로 나타났다.

• 품질경영학회지
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• 제18권2호
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• pp.93-99
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• 1990

This paper considers the selection of process plans for a flexible manufacturing machine. Most of the planning models for the automated manufacturing systems are based on the assumption that for each part there is only one process plan available. This paper considers that for each part a number of different process plans are available, each of which may require specific types of tools. If the requisite tools are not on the machine, one or more tool switches must occur before the process plan can be processed. This paper develops an optimal algorithm of branch and bound method for the selection of process plans to minimize the number of tool switches.

• 대한산업공학회지
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• 제26권2호
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• pp.165-170
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• 2000

In order to perform a successful material cutting process, the operators are to select the suitable machining tools and cutting conditions for the cutting environment. Up to now, this has been a complicated procedure done by the data in the tool manufacturers' paper catalog and the operator's experiencial knowledge, so called heuristics. This research is motivated by the fact that using computer techniques in processing vast amount of data and information, the operator can determine the tool and cutting condition easily. In the developed program, the selection of milling cutter, insert, and components are combined to provide optimal cutting speed, depth of cut, feed rate, rpm, and power. This program also provides the selection routine for end mill, drilling, turning, and grinding where the suitable tools are selected by workpiece, holder type, cut type, and insert shape.

• International Journal of Contents
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• 제5권3호
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• pp.40-49
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• 2009

While numerous studies have suggested the significance of uncertainty during the process of information-seeking, less research has investigated user uncertainty in the actual search process using a real system. This study investigated user perceptions of uncertainty in the process of the selection of information retrieval system in the real information-seeking process. Considering the role of commercial Web search engines as supplementary tools for traditional bibliographic databases in academic research environments, this study analyzed the selection behavior of scholarly researchers, who use such search tools for their academic study. The researchers were limited to the discipline of science in order to understand user perceptions in this field. The findings revealed various dimensions, types, and incidents of uncertainty. Variations appeared in different incidents of uncertainty relating to the unique characteristics of the subjects' information-seeking context. The identification of three principal origins of uncertainty based on the different types of uncertainty generated implications to improve information systems and services.

• 한국정밀공학회지
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• 제15권5호
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• pp.161-166
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• 1998

As a part of the configuration design expert system of machine tools, inference mechanisms are constructed in this paper. In addition to procedural inference, the method of multivariable inference is considered as an efficient approach to deal with the cases of highly coupled condition. We propose a generalized multi-variable inference procedure. The procedure is applied to the type selection module of the configuration design expert system of machine tools in order to demonstrate the efficiency and validity.

• 컴퓨터교육학회논문지
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• 제17권4호
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• pp.13-21
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• 2014

최근 프로그래밍 교육의 중요성이 국내외에서 나타나고 있다. 그리고 다양한 교육용 프로그래밍 도구가 나타나면서 프로그래밍 도구 선택을 위한 일정한 기준이 필요하게 되었다. 이에 이 연구에서는 초보 프로그래머와 초중등 학생들을 위한 교육용 프로그래밍 언어의 선택 기준을 개발하고 그 타당성을 검증하고자 하였다. 이를 위해 우리는 선행연구와 전문가 검토를 통해 4개 영역의 28개 항목으로 구성된 교육용 프로그래밍 언어의 선택 기준을 수립하였다. 그리고 수립된 선택 기준에 대한 타당성 검증을 위해 20명의 델파이 전문가 패널을 선정하여 델파이 조사, 분석을 하였다. 수행 결과, 개발된 기준의 4개 영역은 컴퓨터과학과의 연계성, 프로그래밍 언어의 용이성, 개발 환경의 유용성, 외부 환경 지원의 편리성 등이다. 그리고 델파이 조사를 통해 타당성 기준을 충족시키지 못한 9개 항목은 삭제하고 최종적으로 확정된 선택 기준은 19개 항목이다.