• Journal of Nuclear Fuel Cycle and Waste Technology
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• 제1권1호
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• pp.83-92
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• 2013

A novel methodology to evaluate remote dismantling equipment for a reactor pressure vessel (RPV) in a decommissioning project is presented in this paper. The remote dismantling equipment, mainly composed of cutting tools and positioning equipment, is absolutely required to cut and handle highly radioactive and large components in nuclear power plants (NPPs); this equipment has a great effect on the overall success of the decommissioning project. Conventional evaluation methods have only focused on cutting technologies or positioning equipment, although remote dismantling equipment cannot achieve its goal without organic interaction between the cutting tools and the positioning equipment. In this paper, the cutting tools and the positioning equipment are evaluated by performance parameters according to their original characteristics, the relationship between the two systems, and common factors. Finally, the remote dismantling equipment used in recent decommissioning projects has been evaluated based on the proposed methodology. The results of this paper are expected to be useful for future decommissioning projects.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1997년도 추계학술대회 논문집
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• pp.213-218
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• 1997

Thermal deformation of machine origin of machine tools due to internal and external heat sources has been the most important problem to fabricate products with higher accuracy and performance. In order to solve this problem, GMDH models were constructed to estimate thermal deformation of machine origin for a vertical machining ceneter through measurement of temperature data of specific points on the machine tool. These models are nonlinear equations with high-order polynomials and implemented in a multilayered perceptron type network structure. Input variables and orders are automatically selected by correlation and optimization procedure. Sensors with small influence are deleted automatically in this algorithm. It was shown that the points of temperature measurement can be reduced without sacrificing the estimation accuracy of $\pm$5${\mu}{\textrm}{m}$. From the experimental result, it was confirmed that GMDH methodology was superior to least square models to estimate the thermal behavior of machine tools.

• 한국정보시스템학회지:정보시스템연구
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• 제32권2호
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• pp.153-176
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• 2023

Purpose As non-face-to-face work environments become common due to COVID-19, interest in online collaboration tools that can communicate smoothly without time and space limitations is continuously increasing. Most of the prior studies are about the introduction, use intention, and satisfaction of cloud computing-based collaboration tools, and studies on the effects of collaboration tools on work-life balance and quality of life are somewhat lacking. Therefore, in this study, the characteristics of cloud computing-based collaboration tools were derived, and the effect on job satisfaction during work and job stress outside of working hours was confirmed. Design/methodology/approach This study applied the S-O-R framework and conducted an online survey of office workers who used cloud computing-based collaboration tools for more than three months. Hypotheses were tested using structural equations. Findings As a result of the analysis, among the characteristics of collaboration tools, stability, usefulness, and interoperability had higher job satisfaction as more stimuli were applied. In addition, the higher the job satisfaction during work, the higher the job performance, work-life balance, and quality of life.

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제12권6호
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• pp.349-357
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• 2006

본 논문에서는 프로그램의 성능을 향상시키기 위하여 프로그래머들이 다른 성능조율 대안들을 평가하는 것을 돕는 새로운 평가 방법론을 소개한다. 이 방법론은 조율 대안이 채택된 경우의 성능을 평가할 수 있게 한다. 구체적으로 말하자면, 성능 병목 지점의 확인을 위하여 프로그램 구성 요소들에서 소요되는 시간을 수량화하는 전통적인 성능 평가 방법론과는 대조적으로 분산 또는 병렬 프로그램이 처리하는 일의 이동 이후의 성능을 예측한다. 따라서, 이 방법론은 일의 처리 장소를 변경함으로써 성능을 향상시키는 것에 대한 가이드라인을 제공한다. 이 방법론을 사용하면 기반 네트워크 변경에 따른 성능에 대한 파급효과도 예측할 수 있다. 이 방법론은 조율할 프로그램이 실행되는 동안 점진적으로 그리고 온라인으로 성능을 평가할 수 있다. 본 논문에서는 이 방법론을 구현한 후 사용했을 때 여섯 프로그램들의 검사 집합에 대하여 다른 조율 대안들의 성능을 정확히 예측할 수 있다는 실험 검증 결과를 보인다.

• KIEAE Journal
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• 제9권5호
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• pp.13-20
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• 2009

This study suggested practical application of decision aid tool on re-evaluation of current buildings with a focus on a energy and economics evaluation methodology. In Europe, over forty percent of all construction activities are for retrofit. For efficient construction, various tools for re-evaluating existing buildings have been developed and are in use. Legislations of relevant laws and studies are actively initiated. In particular, EPIQR (Energy Performance Indoor environment Quality Retrofit), which was developed through the EU's Third and Fourth Framework Programs laid a foundation on a new concept-based decision aid tool for re-evaluation of existing buildings. As for actual applications, based on this, EPIQR+ was developed to be in line with a building maintenance guideline (SIA 469) and is actively applied to public buildings. This tool quantifies the degree of damages of existing buildings and suggests alternatives to users in energy (SIA 380/1) and economical perspectives. This study examined these preceding tools and suggested some trenchant approaching for more comprehensive and efficient use of re-evaluation tools in building maintenance.

• Journal of Communications and Networks
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• 제7권1호
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• pp.87-92
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• 2005

This paper presents basic queueing analysis contributing to teletraffc theory, with commonly accessible mathematical tools. This paper studies queueing systems with bulk arrivals. It is assumed that the number of arrivals and the expected number of arrivals in each bulk are bounded by some constraints B and (equation omitted), respectively. Subject to these constraints, convexity argument is used to show that the bulk-size probability distribution that results in the worst mean queue performance is an extremal distribution with support {1, B} and mean equal to A. Furthermore, from the viewpoint of security against denial-of-service attacks, this distribution remains the worst even if an adversary were allowed to choose the bulk-size distribution at each arrival instant as a function of past queue lengths; that is, the adversary can produce as bad queueing performance with an open-loop strategy as with any closed-loop strategy. These results are proven for an arbitrary arrival process with bulk arrivals and a general service model.

• Journal of information and communication convergence engineering
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• 제15권2호
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• pp.117-122
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• 2017

Three-dimensional integrated circuits (3D ICs), starting with memory cubes, have entered the mainstream recently. The benefits many predicted in the past are indeed delivered, including higher memory bandwidth, smaller form factor, and lower energy. However, 3D ICs have yet to find their deployment in aerospace applications. In this paper we first present key design tools and methodologies for high performance, low power, and reliable 3D ICs that mainly target terrestrial applications. Next, we discuss research needs to extend their capabilities to ensure reliable operations under the harsh space environments. We first present a design methodology that performs fine-grained partitioning of functional modules in 3D ICs for power reduction. Next, we discuss our multi-physics reliability analysis tool that identifies thermal and mechanical reliability trouble spots in the given 3D IC layouts. Our tools will help aerospace electronics designers to improve the reliability of these 3D IC components while not degrading their energy benefits.

• 한국융합학회논문지
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• 제9권9호
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• pp.41-46
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• 2018

식스 시그마 기법은 제품과 서비스의 품질관리와 원가 절감을 통한 생산성 향상 뿐만 아니라, 연구개발을 비롯한 기업 경영의 다양한 영역에 적용할 수 있는 관리 기법이다. 또한 정보 융합 시대의 실현을 위하여 고밀도 정보저장 매체 및 장치의 개발은 필수적 요건이다. 본 논문에서는 고밀도 정보저장 매체 개발 과제에 식스 시그마 방법론과 기법을 적용한 사례에 대하여 보고하고자 한다. 식스 시그마 프로세스는 표준적으로 사용되는 DMAIC 프로세스를 적용하였으며 각 단계별로 달성하고자 하는 목표와 적용한 도구 및 결과에 대하여 상세히 설명하였다. 본 기법을 활용함으로써 $250Gb/in^2$ 이상의 높은 기록밀도를 갖는 정보저장 매체를 균일하고 재현성 있게 형성할 수 있는 제조 방법을 확립하였으며, 제조된 매체의 자기적 특성과 성능을 자기이력곡선을 통하여 확인하였다.

• 4차산업연구
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• 제4권1호
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• pp.11-18
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• 2024

Purpose: The purpose of this study is to develop a geography class teaching and learning guide that enables learners to realistically explore the characteristics of the world's climate and geographical environment using digital tools. Research design, data and methodology: We review previous research on classes using goal-based scenario learning models, gamification, and digital tools, and explore tools that can be applied to world geography classes. Based on the exploration results, a goal-based scenario learning module is designed and a strategy for promoting educational gamification is established based on the ADDIE instructional design model. Results: The study comprises four sessions. Sessions 1-3 involve performance evaluations using a goal-based scenario learning module. Learners create game characters reflecting geographical characteristics, present results, and proceed with 3D modeling. In Session 4, a gamification class using Google Sites on the CoSpaces metaverse platform will be conducted. Conclusions: The study introduces a goal-based scenario learning model and a gamification class using digital tools to empower learners in exploring geographical diversity and its impact on lifestyles. Utilizing an accessible online platform, the study provides practical measures for integrating digital tools into geography education, addressing the current importance of digital technology in teaching.

• 국제학술발표논문집
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.1509-1514
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• 2009

CII BM&M(Benchmarking & Metrics) in USA and DTI(Department of Trade and Industry) in UK have built up systems that enable performance measuring and made the results of performance measurement comparable between projects to utilize them as benchmarking tools. By comparing the results of performance measurement, it is possible to grasp the success level of project management and to establish the direction of management. However, construction projects are much diversified and even those projects with the same work type have different attributes. Therefore, simply comparing the results of project performance measurement without considering the characteristics of projects is not justifiable and affects the reliability of the benchmarking results. Therefore, to solve this problem, this study presents a methodology that makes it possible to compare the individual construction projects considering various characteristics. The benefits and importance of project characteristics to overall project performance will be quantitatively expressed and they will be reflected on the results of performance management. By maximally converting multiple projects with different characteristics into the same projects through a new methodology to convert different projects into the same level utilizing such utility-bases and comparing the performances of those projects, project performance results can be utilized in project management as a tool for more accurate decision making and as a robust benchmarking tool.