• Proceedings of the Korea Contents Association Conference
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• 2006.11a
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• pp.84-89
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• 2006

Keeping pace with the speed of development of science & technology domain, the domain terms continuously repeat the step of creation and extinction. This study tries to define term life cycle and analyze extracted terms from a large corpus with the viewpoint. We chose 'ETNEWS' corpus which includes about 17 million Eojeols for 12 years because it is easy to inspect the transition of term life cycle and the corpus represents computer, IT, and electrotechnology domains. This study acquired several useful conclusions including the relation between specificity and life of terms. We expect that term life cycle will contribute to analyze the competition of similar technologies and determine which term be registered into general dictionary.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.6-14
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• 2007

The objective of this research is to comparative LCA(life cycle assessment) between two different model of Electric Motor Unit(EMU).the environmental impact of Aluminum body Electric Motor Unit(EMU) and Stainless Steel(STS) body Electric Motor Unit(EMU). LCA process consists of four steps which are goal, scope definition, life cycle impact analysis(LCIA) and life cycle interpretation. ISO 14044 provides the LCA standard method which can be conducted by using comparative LCA. From the research it is foung that the Aluminium Body Electric Motor Unit (EMU) is 3.6ton heaver than Stainless Steel(STS) body Electric Motor Unit(EMU). The system boundary of both Electric Motor Unit (EMU) are same life span and travel same distance. These both Electric Motor Unit (EMU) has same kind of environmental impact which is maximum Ozone Depletion(OD). During using period of these two models, the Aluminium Body Electric Motor Unit(EMU) has more global warming(GW) effect but Stainless Steel(STS) body Electric Motor Unit(EMU) has more Ozone Depletion(OD) effect. The above result is obtained by using LCA software PASS verson 3.1.3.

• Journal of the Korean Society for Heat Treatment
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• v.16 no.3
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• pp.141-147
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• 2003

The effects of heat treatment on the fatigue life and welding residual stress of welded plates were investigated in this study. The plates were welded by flux cored arc welding process, and post weld heat treated at $600^{\circ}C$ for 1 hour. The residual stresses of welded plates before and after post weld heat treatment were measured by hole drilling method. To measure the fatigue life of welded plates, low cycle fatigue tests under strain control and high cycle fatigue tests under load control were performed respectively, by using cylindrical specimens containing weld metal and heat affected zone. The obtained result shows that the post weld heat treatment reduces the residual stress, and resultantly changes the fatigue life of welded plate. Goodman diagrammatic analysis has also been performed to study the effect of post weld heat treatment on the high cycle fatigue life.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2008.04a
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• pp.393-398
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• 2008

The environment is the important resource to use as well as to conserve for the development. Since 1990s, it has accentuated the importance of the environment and tried to conserve the environment in many areas. Among many area, the building industry has played a role to destruct the environment for providing the living decent space and brought the environmental affect. Therefore, the building industry should endeavor to mitigate the environmental affect. In building life cycle, it consumes the energy and natural resources. But it is difficult to evaluate the environmental affect during the whole building life. It is impossible to calculate the environmental affect without the much time and effort. Therefore. it requires the easy and handing program to calculate the affect to environment in each building life cycle. Until now, many program for assessing the affect to the environment have been developed and limitedly used because of the assessment scope and contents. In this paper, it aimed at developing the assessment program of LCA, focused on the energy consumption and carbon-dioxide emission compared with the domestic and foreign concerned programs. The developed program is divided into 3 areas; construction, maintenance, demolition.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.16 no.11
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• pp.1060-1067
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• 2004

To apply an analysis method of life cycle cost when assessing economics of equipment system, we should basically set up preconditions such as useful life, price escalation rate, interest rate, etc. as well as consider a calculation algorism of source energy and heat source system, which is a complex process for life cycle costing. For this reason, equipment designers tend to plan heat source systems, without a thorough investigation on economics of alternative systems at the pre-design phase. In this process, architectural designers should adopt a proper heat source system, which is one of the most important factors for planning an appropriate architectural design, through a discussion with equipment designers in a short time. In order to offer an evaluation method for equipment designers to analyze economics of an alternative heat source system easily at the pre-design phase, this research would define the simplified economics, evaluation method through analysis of existing papers for economics evaluation, and examine validity through comparison of simplified method values ($LCC_{EC}$) and life cycle costing values ($LCC_{15}$) for six alternative heat source systems.

• International Journal of Railway
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• v.9 no.1
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• pp.10-14
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• 2016

Life cycle cost analysis is compulsively required for the system operation. System operation costs are consisted of acquisition, operation, maintenance and so on. In the beginning of the system planning, we need to take into account of various costs following the system operating. To implement LCC, we need to analyze system life cycle to identify all costs during system life. The costs can be divided into three parts. The first part is purchasing cost, the second for operating cost and the last for disposal cost. The second operating cost can be decomposed of operating cost included labor, energy consumption cost for system running, maintenance costs to keep systems healthy, delay cost caused from maintenance and hazard cost, and so on. In this paper, we carried out for railway locomotives which operate over more 30years and which cost about 10 million USD. We decompose the life cycle of the locomotives and break down the locomotives into subsystems to require maintenance or not, and subsystems to need energy or not. We showed how to decide optimal locomotives through cost identification and system breakdown.

• Land and Housing Review
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• v.12 no.4
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• pp.31-40
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• 2021

In the present article we examine life-cycle housing demand for Korea. Distinguished in this work from prior research is the consideration of non-monocinity in the life-cycle housing demand. To this end, we adopt spline logistic regression models. Our findings suggest that life-cyclicity is most clear in Korean housing demand; namely, 1) small (mid-large) house ownership falls (grows) dramatically as households age into middle aged; 2) middle aged households do not participate in the rental or purchase market actively; 3) elderly population does not dispose of their housing to the same extent as younger generations acquire housing.

• Journal of Photoscience
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• v.10 no.2
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• pp.195-198
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• 2003

In the cellular response to DNA damaging agents, cells undergo cell cycle arrest or apoptosis against irrepairable DNA damage. RpS3 is known to function as UV DNA repair endonuclease III and ribosomal protein S3. In this study, we used normal and rpS3-overexpressed 293T cells to examine the role of rpS3 in response to DNA damaging agents. When 293T cells transfected with rpS3 were irradiated with UV, the pattern of cell cycle was dramatically changed in comparison with un-transfected 293T cells. We also found that the expression of rpS3 in normal cells was increased by treatment with DNA damaging agents. By means of Western and Northern blot analyses in rat tissues, we showed the expression pattern of rpS3 protein and its mRNA. These data suggest that DNA repair and cell cycle arrest are interrelated to each other through rpS3, and the increased expression of rpS3 seems to regulate the cell cycle arrest by DNA damaging agents.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2008.11a
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• pp.291-296
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• 2008

For the past two decades, 3D/4D CAD research has heel mainly focused on the design and construction phase of a facility life-cycle. However, there has been a general notion that the strength of 3D/4D CAD lends itself to other phases such as planning, operation and maintenance. In this research, a 3D/4D CAD model was generated in a commercial software platform. Then, the traditional 1:fe cycle facility management procedures are reviewed to, see any possible improvement opportunity with the 3D/4D CAD model as an example. A focus group interview, in conjuction with an extensive literature review, produced the list of area where 3D/4D CAD model could significantly benefit the traditional life cycle facility practices. Finally, a questionnaire-based survey was conducted with 155 respondents to statistically verify the feasibility of 3D/4D CAD for life cycle facility management.

• Journal of Computing Science and Engineering
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• v.7 no.2
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• pp.81-88
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• 2013

In cognitive radio or dynamic spectrum access networks, a rendezvous represents meeting two or more users on a common channel, and negotiating to establish data communication. The rendezvous problem is one of the most challenging tasks in cognitive radio ad hoc networks. Generally, this problem is simplified by using two well-known mechanisms: the first uses a predefined common control channel, while the second employs a channel hopping procedure. Yet, these two mechanisms form a life cycle, when they simplify the rendezvous problem in cognitive radio networks. The main purpose of this paper is to point out how and why this cycle forms.