• 한국기계가공학회지
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• 제13권3호
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• pp.56-62
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• 2014

During the hot forging process, the most common cause of tool failure is wear. Tool wear results in the gradual loss of part tolerances, after which eventually the tool must be replaced or repaired. In order to maximize the lifetimes of forging tools, it is important to investigate the wear mechanisms of these tools. In this study, the hot forging of the outer race of an automotive constant-velocity joint was analyzed by a finite element method to investigate the wear distribution, especially the amount and location of the maximum expected wear damage, using Archard's wear model, which was modified considering the forging temperature. Forging analyses were carried out after modifying blocker forging tools based on established versions. The modified blocker tools resulted in an increase in the tool life up to 31% with a finisher punch.

• 임상간호연구
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• 제16권3호
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• pp.5-23
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• 2010

Purpose: This study was conducted to determine the validity and reliability of performance measurement tools based on the nursing process for prevention and management of pressure ulcers, falls and pain. Methods: The performance measurement tools were reviewed by a panel of experts and refined on the basis of the panel's suggestions. The validity of the performance measurement tools was measured by surveying hospital nurses. The reliability of these tools was tested by having nursing experts use the tools in five nursing units to assess nursing performance in prevention and management of pressure ulcers, falls and pain. Results: The performance measurement tools in this study were found to be acceptable as tools to evaluate quality of nursing care in pressure ulcers, falls and pain. The reliability of the performance measurement tools was acceptable. Conclusion: These results indicate that the performance measurement tools developed in this study are valid and reliable instruments to monitor and improve quality of nursing care in prevention and management of pressure ulcers, falls and pain.

• 한국디지털건축인테리어학회논문집
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• 제12권1호
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• pp.99-108
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• 2012

The purpose of this study is to demonstrate the improvement of the education process in architectural engineering through the analysis of the advantages of the BIM tool. As public institutions and owners have been introduced to Building Information Modeling (BIM) tools, BIM has become an important factor in the design process in undergraduate university programs. First, BIM-related issues, domestic and overseas, was analyzed. Second, a case study of BIM education was analyzed at K University under the ABEEK process. Students participated a survey about the understanding of BIM and the use of BIM tools. As a result of the analysis, six advantages of the use of BIM tools were found. As a result of this research, following five issues are found about BIM education through advantage of using BIM tools. The result of this research was verified by conducting a survey on the usage of BIM softwares. The limitation of this study was to analyze the case study of only limited numbers of participants at the university.

• 국제학술발표논문집
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• The 6th International Conference on Construction Engineering and Project Management
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• pp.718-719
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• 2015

As a recent global trend, the majority of plant projects are delivered through EPC or EPC-turnkey contracts, where a contractor's liability is more complicated because of the mega size scale and financing method. Previous researches have been lacking a practical usability for project members for liabilities of contracts. Those were focused on solving the claims or schedule calculation issues only. The objective of the present study was to develop a validation process for LDs (liquidated damages) in contractor's liabilities with various case studies and expert judgments. As summarized in this paper, the processes and tools were developed with project life cycle process. The project preparation phase includes 3 step check lists to determine the Go or No-go for projects. In progress phase, contractors should focus on the response strategies for claims with liabilities. The study concludes that those developed processes and tools will help to manage risk of LDs for the contractors in the overseas projects.

• 한국콘텐츠학회논문지
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• 제16권12호
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• pp.143-150
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• 2016

다양한 접합부간의 조립으로 구조를 이루게 되는 모듈러공법에서 현장설치단계의 모듈조립은 구조물의 구조적인 안정성 및 품질에 직접적인 영향을 미칠 수 있는 매우 중요한 공정이다. 그러나 일반적으로 사용되는 수공구 또는 전동공구는 장시간 사용 시 생산성과 조립품질이 저하되는 문제점을 가지고 있다. 이에 에어공구의 장점을 활용한 모듈러주택 전용 조립공구가 개발되었으나, 공구별 성능을 비교하여 성능을 비교 및 평가하는 실험적인 분석은 미흡하였다. 이에 본 연구는 모듈러주택 조립에 사용되는 기존 조립용 공구와 모듈조립용 에어공구를 현장에 적용하여 구조물의 조립품질과 생산성을 공구별로 측정하여 비교 분석 하였다. 그 결과, 기존 조립용 공구와 비교하여 모듈조립용 에어공구가 생산성 및 품질 측면에서 더 우수한 것으로 분석되었다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.633-636
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• 2005

Imprint lithography is a promising method for high-resolution and high-throughput lithography using low-cost equipment. As with other nanoimprint methods, ultraviolet-nanoimprint lithography (UV-NIL) resolution appears to be limited only by template resolution, and offers a significant cost of ownership reduction when compared to other next generation lithography (NGL) methods such as EUVL and 157 nm lithography. The purpose of this paper is to suggest optimum values of control parameters of Imprio 100 manufactured by Molecular Imprint, Inc., which is the first commercially available UV-NIL tool, for sound nanoimprint. UV-NIL experiments were performed on Imprio 100 to find dispensing recipe for avoiding air entrapment. Dispensing recipe related to residual layer thickness and uniformity was optimized and 40 nm thick residual layer was achieved.

• 한국기계가공학회지
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• 제11권2호
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• pp.20-26
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• 2012

Recently, micromilling process has been progressed to meet the variety of the industry demands in micromolds and precision components. As a result, more and more commercialized micro tools and machines become available during last few years. This paper reviews the recent progress of micromilling technology in last five years. The results in process, machine tools, and micro tool fabrications are discussed.

• 소성∙가공
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• 제19권1호
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• pp.50-58
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• 2010

In order to successfully implement hot die forging process for the large-size titanium alloy products, it is necessary to devise a customized heating method for the billets and the die tools, as well as the die tool design. This study aims at establishing a hot die forging process of the large-size titanium alloy container products by applying the warm die, semi-hot die and hot die forging process step-wise. To accomplish this purpose, forging mechanism and the die tools were designed considering the strength of die materials at the given die heating temperature. The movable heating devices for the billet and the die tools were also introduced to prevent overcooling of billet and die tools. To verify the applicability of the designed forging process, real-size forging tests were carried out and the quality of forged products, including dimension, surface condition, microstructure and the mechanical properties was evaluated.

• 한국과학교육학회지
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• 제39권4호
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• pp.545-562
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• 2019

이 연구의 목적은 고등학생들의 통합 탐구 기능 향상을 위한 인지적 스캐폴딩 도구를 개발하고, 그 적용 효과를 탐색하는 것이다. 이를 위해 문헌 연구 및 선행 연구 결과를 토대로 통합 탐구 기능 교육을 위한 수업용 자료 1종과 학생들이 자신의 탐구 능력 수준에 맞추어 선택적으로 학습할 수 있는 개별 학습용 자료 2종을 포함한 인지적 스캐폴딩 도구를 개발하였다. 또한, 통합 탐구 기능에 대한 학생들의 수준을 조사하기 위한 도구로 가설-연역적 탐구 형식으로 구성된 사전, 사후 검사용 탐구 과제를 1개씩 개발하였다. 인지적 스캐폴딩 도구의 효과를 검증하기 위하여 실험군과 대조군의 사전, 사후 검사에 대해 추리 통계를 실시하였다. 또한, 인지적 스캐폴딩 도구의 적용 여부에 따른 고등학생들의 통합 탐구 능력을 Rasch 모형에 따른 Wrightmap을 산출하여 비교하였고, 통합 탐구 기능의 각 요소에 대한 학생들의 수준 변화 양상을 확인하였다. 연구 결과, 인지적 스캐폴딩 도구를 사용했던 실험군은 대조군에 비해 탐구 설계, 자료 수집 및 변환, 자료 해석, 결론 도출 등 모든 평가 요소에서 유의미하게 높은 점수를 보였다. 또한, 인지적 스캐폴딩 도구를 활용했던 학생들은 전반적으로 통합 탐구 능력이 향상되었고, 통합 탐구 기능의 각 요소에서 높은 수준으로 뚜렷하게 변화되는 양상을 보여주었다. 이러한 연구 결과는 학생들이 과학 탐구를 수행하는 과정에서 직면하는 기능적 장벽을 완화 또는 제거하기 위해 인지적 스캐폴딩 도구를 적극적으로 활용할 필요가 있음을 시사한다.

• 대한산업공학회지
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• 제15권2호
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• pp.45-55
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• 1989

This paper deals with development of a computer-aided process selection and sequencing technique and its software for metal cutting processes of rotational parts. The process selection procedure consists of selection for proper machining operations and machine tools suitable for the selected operations. Machining operations are selected based on machining surface features and machine tools are selected by employing a conversion table which converts machining operations into machine tools. The process sequence is determined by the proper manipulation of the precedence relation matrix. A computer program for the proposed technique is developed by using Turbo-Pascal on IBM PC/AT compatible system. The proposed technique works well to real problems.