• 산업공학
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• 제18권4호
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• pp.504-511
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• 2005

The NP-hard channel assignment problem becomes more and more important to use channels as efficiently as possible because there is a rapidly growing demand and the number of usable channel is very limited. The hybrid genetic and local search (HGLS) method in this paper is a hybrid method of genetic algorithm with no interference channel assignment (NICA) in clustering stage for diversified search and local search in tuning stage when the step of search is near convergence for minimizing blocking calls. The new representation of solution is also proposed for effective search and computation for channel assignment.

• 한국실내디자인학회논문집
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• 제14권2호
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• pp.120-127
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• 2005

The purpose of this study was to examine preferential unit planning components of high-rise residential buildings across family life cycle stages. The questionnaire survey was adopted in this study, and 110 cases were used for data analysis. Based on the age of the oldest child, the family life cycles used in the study were divided into four stages: early childhood, elementary school, adolescence, and adulthood. The findings showed that the preference of the unit planning components across the stages was distinct; families in the stage of early childhood and adolescence had the growing needs for spatial features, and regarded living-related features as important. Families in the stage of adulthood tended to have larger spaces. It was noticed that unit planning components needed to be more differential when the combined effect of both family life cycle stages and housing size was considered.

• 한국CDE학회논문집
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• 제4권1호
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• pp.43-51
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• 1999

Producing the relevant information (features) from the CAD models of CAM, called feature recognition or extraction, is the essential stage for the integration of CAD and CAM. Most feature recognition methods, however, have problems in the recognition of intersecting features because they do not handle the intersection geometry properly. In this paper, we propose a machining feature recognition algorithm, which has a solid model consisting of orthogonal primitives as input. The algorithm calculates candidate features and constitutes the Intersection Geometry Matrix which is necessary to represent the spatial relation of candidate features. Finally, it recognizes machining features from the proposed candidate features dividing and growing systems using half space and Boolean operation. The algorithm has the following characteristics: Though the geometry of part is complex due to the intersections of design primitives, it can recognize the necessary machining features. In addition, it creates the Maximal Feature Volumes independent of the machining sequences at the feature recognition stage so that it can easily accommodate the change of decision criteria of machining orders.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2011년 춘계학술대회논문집
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• pp.169-172
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• 2011

Recently, railroad long tunnels are increasing and growing longer due to topological feathers like a lot of mountain in Korea. But fire disaster of a long tunnel cause many people to injury and death. For that reason, at the early design stage of a long tunnel, risk assessment and mitigation measure of risk for satisfying tunnel safety are required. According to the railroad facility safety standard (Korean MLTM Announcement No. 2006-395), risk assessment for railroad-tunnel fire should be performed when design stage. Therefore, various methods of risk assessment for tunnel fire have been studied and applied. In the paper, QRA(Quantitative Risk Analysis) for fire risk assessment by using CFD code is presented and the usefulness of CFD is discussed.

• 한국경영과학회지
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• 제19권1호
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• pp.53-67
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• 1994

Over the last decades, interest in the application of decision support systems (DSS) in organizations has increased rapidly. Despite the growing number of investigations exmaining decision support system, relatively few empirical studies have evaluated the effects of DSS on problem-solving processes. This study examined, using a computer simulation technique, the effects of recursion in problem-solving processes on the problem-solving time. Results indicate that the recursions at the early stage of problem-solving processes scarcely influenced the problem-solving time, which is contrasted with the case of the recursions at the final stage.

• Journal of Biosystems Engineering
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• 제24권1호
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• pp.25-30
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• 1999

The effectiveness of many greenhouse environment control methodologies depends on the growth information of crops. Acquisition of the growth information of crops requires a non-invasive and continuous monitoring method. Crop growth monitoring system using digital imaging technique was developed to conduct non-destructive and intact plant growth analyses. The monitoring system automatically measures crop growth information sends an appropriate control signal to the nutrient solution supplying system. To develop the monitoring system, a linear model that explains the relationship between the fresh weight and the top projected leaf area of a lettuce plant was developed from an experiment. The monitoring system was evaluated buy successive lettuce growing experiments. Results of the experiments showed that the developed system could estimate the fresh weight of lettuce from a lettuce image by using the linear model and generate an EC control signal according to the lettuce growth stage.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집
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• pp.721-729
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• 2009

Recently, there has been growing necessity to estimate the future travel demand of high speed train because the circumstance of high speed train service is rapidly changing with the launching of 2011 second stage of Gyeongbu high speed railway(Dongdaegu-Busan) and the completion of 2014 first stage of Honam high speed railway(Yongsan-Gwangju), etc. This study was designed to estimate future travel demand by analyzing the transport performance and train service characteristics of Gyeongbu and Honam line. This study presents the maximum load section and the changed future travel demand, which will be applied to establish a train operation plan.

• Journal of Korean Neurosurgical Society
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• 제39권4호
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• pp.310-313
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• 2006

Although lipomyelomeningocele and dermoid cyst are formed during a similar embryologic developmental stage of 'neural tube formation', they are caused by entirely different embryologic mechanisms. We encountered a case, which has not been previously reported, that had a lumbar subcutaneous dermoid cyst associated with lipomyelomeningocele. A 52-year-old man presented with a slowly growing lumbar mass of 3 years duration, which had been present since birth. Lumbosacral magnetic resonance imaging[MRI] showed lipomyelomeningocele at the L3, 4 and 5 levels and a subcutaneous cystic mass of high signal intensity on the T2 weighted image and iso or low signal intensity on the T1 weighted image. He underwent total resection of the lumbar subcutaneous mass. Intraoperative findings and histological examination were consistent with the preoperative diagnosis of a 'dermoid cyst'. We demonstrate that the formation of a dermoid cyst might coexist with lipomyelomeningocele during the embryologic developmental stage.

• 한국컴퓨터정보학회논문지
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• 제23권12호
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• pp.115-122
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• 2018

As the proportion of software in weapon systems increases, the impact of software on the overall system is growing. As a result, software quality management becomes important, and related regulations and work manuals for quality assurance activities at each stage in the R & D process are becoming more sophisticated. However, due to the characteristics of the weapon system software that is developed as a customized form for the purpose of a specific mission, there are limits to specifying and definitizing the detailed requirements (upper and lower level) according to various operational concepts during the development process. Due to this, software modification (patch change, shape change due to upgrade, etc.) occurs on account of many defects and performance improvement in the mass production and operation stage after the development is completed. In this study, we analyze the characteristics of these weapon system softwares and propose quality improvement methods based on ISO / IEC / IEEE 29119 test method.

• 환경위생공학
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• 제16권3호
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• pp.54-60
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• 2001

The need and concern about ecosystem are growing rapidly. However, ecosystem management systems are still in the first stage since the data are handled locally and separately. It results in the waste of money and time. In this research, we designed and implemented ecosystem management system of stream region using geographical information system(GIS) that is able to be used to manage the natural resource efficiently. It is expected to be used as a useful tool for Improvement of environment and management of ecosystem as well as recovery of natural environment.