• 산업경영시스템학회지
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• 제18권34호
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• pp.83-89
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• 1995

We call as plant life cycle the process starting from plant plan, design to disuse by way of construction, operation, but the plant facility inside it comes to changes of cope with various inner factor like blazing phenomenon and outer factor according to economic state. On the presumption of these factors, the problem is brought about how plant should be managed, this study attempt to suggest the conservation management through economic evaluation in investment design and alternative, that is, methodology connecting that of economical efficiency evaluation based on LCC(Life Cycle Costing) thinking method and facility management with that of life prediction.

• 한국기계가공학회지
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• 제14권1호
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• pp.1-8
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• 2015

Productivity of machining using machine tools is affected by cutting conditions such as cutting speed, feedrate and depth. However, undesirable conditions that lengthen the machining cycle and shorten the tool life occur frequently because determination of cutting condition is known to depend on human experience. This paper presents a method of cycle reduction by removing undesirable conditions. For cycle reduction, maximum cutting load is determined using commercial FEM simulation code. The feedrate in the NC program is altered based on a predetermined cutting load value. To make a decision on the proposed effectiveness, a simulation is performed for the brake hub parts of an automobile. From the evaluation, it was found that the cycle reduction was under 15%.

• 대한산업공학회지
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• 제34권4호
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• pp.386-397
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• 2008

Due to the rapid advancement of technologies, a growing number of innovative products with a short life-cycle have been introduced to the market. As the life-cycles of such products are shorter than those of durable goods, the demand variation during the life-cycle adds to the difficulty of inventory management. Traditional inventory planning models and techniques mostly deal with products that have long life-cycles. The assumptions on the demand pattern and subsequent solution approaches are generally, not suitable for dealing with products with short life-cycles. In this research, inventory replenishment problems based on the logistic demand model are formulated and solved to facilitate the management of products with short life-cycles. An extended Wagner- Whitin approach is used to determine the replenishment cycle, schedules and lot-sizes.

• 한국정보전자통신기술학회논문지
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• 제1권2호
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• pp.39-50
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• 2008

Developing computational methods for identifying cell cycle-regulated genes has been one of important topics in systems biology. Most of previous methods consider the periodic characteristics of expression signals to identify the cell cycle-regulated genes. However, we assume that cell cycle-regulated genes are relatively active having relatively many interactions with each other based on the underlying cellular network. Thus, we are motivated to apply the theory of multivariate phase synchronization to the cell cycle expression analysis. In this study, we apply the method known as "Self-Organizing Maps with statistical Phase Synchronization (SOMPS)", which is the combination of self-organizing map and multivariate phase synchronization, producing several subsets of genes that are expected to have interactions with each other in their subset (Kim, 2008). Our evaluation experiments show that the SOMPS algorithm is able to detect cell cycle-regulated genes as much as one of recently reported method that performs better than most existing methods.

• 디지털융복합연구
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• 제17권5호
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• pp.11-21
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• 2019

급변하는 교육 기술과 트랜드로 교육용 디지털 콘텐츠를 제공하는 서비스는 기존 콘텐츠가 내용적 변화와 영상적/기술적 품질의 재평가 및 폐기 등이 필요한지에 대한 관리보다는 최신의 기술과 트랜드에 맞춤화된 콘텐츠를 제공하는데 급급했다. 본 연구에서는 교육용 디지털 콘텐츠의 질 관리를 위해 적합한 수명주기와 효과적인 재평가 주기에 대한 시사점을 도출하고자 국내 교육 서비스에 대한 사례를 탐색하였다. 이를 위해 국내 교육 서비스 중 초 중등, 고등, 평생교육에서 대표적인 서비스 사례를 선정하여 담당자로 구성된 초점그룹인터뷰(FGI, Focused Group Interview)를 실시하였다. 인터뷰 결과를 바탕으로 각각 학교급에 따른 교육용 디지털 콘텐츠에 대한 수명주기를 분석하고, 시사점을 도출하였다. 본 연구는 교육용 디지털 콘텐츠에 대해 수명주기에 의한 질 관리의 필요성을 제기함으로써 기관 자체적으로 체계 없이 수행하고 있는 기 콘텐츠의 관리를 좀 더 체계화된 수명주기 정책을 통해 관리하기 위한 기반을 마련하였다는데 의의가 있다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제27권spc호
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• pp.92-98
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• 2022

Although various methods have been proposed to assess groundwater vulnerability, most of the models merely consider the mobility of contaminants (i.e., intrinsic vulnerability), and the attenuation capacity of vadose zone is often neglected. This study proposed an evaluation model for the attenuation capacity of vadose zone to supplement the limitations of the existing index method models for assessing groundwater vulnerability. The evaluation equation for quantifying the attenuation capacity was developed from the combined linear regression and weighted scaling methods based on the lab-scale experiments using various vadose zone soils having different physical and biogeochemical properties. The proposed semi-quantifying model is expected to effectively assess the attenuation capacity of vadose zone by identifying the main influencing factors as input parameters together with proper weights derived from the coefficients of the regression results. The subsequent scoring and grading system has great versatility while securing the objectivity by effectively incorporating the experimental results.

• 기술혁신연구
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• 제20권2호
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• pp.49-74
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• 2012

본 연구에서는 기술의 수명주기에 영향을 미치는 요인에 대해 분석하고, 기존 표준모델에서 활용되고 있는 평가지표를 근거로 개별기술의 수명에 영향을 미칠 평가지표를 분석해 이를 정량화하여, 피인용특허수명(CLT)을 기반으로 개별기술의 속성이 반영된 기술수명주기를 산출하는 개선방법을 제안하였다. 본 연구에서 제안한 방법론은 기존 표준모델의 기술수명주기 산출방법인 한계점을 개선할 수 있는 방법으로 평가대상기술 관계자들에게 도출결과에 대한 설득의 용이성과 기존에 비해 보다 합리적인 기준을 제시함으로서 기술수명주기 도출결과의 타당성 및 활용성을 배가시킬 수 있을 것으로 기대된다.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2009년도 춘계학술대회 논문집
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• pp.385-390
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• 2009

가스터빈의 구조물은 열에 의한 응력과 기계적인 하중에 의한 응력이 동시에 중요하게 작용을 하며 다축응력상태에 놓이게 된다. 가스터빈 엔진은 일반적으로 임무를 가지게 되며 임무를 바탕으로 성능평가, 열전달해석, 구조해석, 수명평가의 일련의 과정을 거치게 된다. 임무에 따라 복잡하게 나타나는 변형율과 응력을 평가하기 위하여 임계평면법을 적용하였으며, 이를 바탕으로 보다 간단하고 편리한 평가 모델인 "The Simplified Model"을 개발하였다. 그리고 개발된 평가방법을 사용하여 터빈휠의 수명평가를 수행하여 결과를 나타내었다.

• 대한기계학회논문집
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• 제18권6호
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• pp.1465-1473
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• 1994

This paper describes the development strategy and contents of a fatigue life evaluation system, FLEVA. The system is composed of 4 parts; material properties, load histories, cycle counting and life prediction. The cycle counting is based on the rain-flow counting method and peak counting method, and the life prediction is performed based on the linear damage rule. Material properties(static, fatigue) are also provided as a database obtained by a computer aided test system. Case study is performed to verify the developed program.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1998년도 춘계학술발표회논문집(2)
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• pp.795-801
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• 1998

Metallic fatigue of Pressurized Water Reactor(PWR) materials is a generic safety issue for commercial nuclear power plants. It is very important to obtain the fatigue usage factor for component integrity and life extension. In this paper, fatigue usage was obtained at the inside surface of Kori unit 2, 3 and 4 RCP casing weld, based on the design transient. And it was intended to establish the procedure and the detailed method of fatigue evaluation in accordance with ASME Section III Code. According to this code rule, two methods to determine the stress cycle and the number of cycles could be applied. One method is the superposition of cycles of various design transients and the other is based on the assumption that a stress cycle correspond to only one design transient. Both method showed almost same fatigue usage in the RCP casing weld.