• Journal of applied mathematics & informatics
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• 제22권1_2호
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• pp.523-533
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• 2006

We analyze two finite buffers queueing system with priority scheduling dependent upon queue length. Customers are classified into two types ( type-l and type-2 ) according to their characteristics. Here, the customers can be considered as traffics such as voice and data in telecommunication networks. In order to support customers with characteristics of burstiness and time-correlation between interarrival, the arrival of the type-2 customer is assumed to be an Markov- modulated Poisson process(MMPP). The service order of customers in each buffer is determined by the queue length of two buffers. Methods of embedded Markov chain and supplementary variable give us information for queue length of two buffers. Finally, performance measures such as loss and mean delay are derived.

• 한국철도학회:학술대회논문집
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• 한국철도학회 1998년도 창립기념 춘계학술대회 논문집
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• pp.137-159
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• 1998

For the construction of railroads in Metropolytan area based upon the outcome of the future demand forecast, a total of 21 lines including electrified double track segment of Ui-Jung-Bu↔Dong-Du-Chun(18.9km) in Kyung-Won Line is expected. Considering the financial difficulties and investment effect of the lines, this in the sequel brings about an important matter of deforming priority Investment plan to build electrified lines among the candidates. In the case of Japan, Tokyo metropolytan area covered In total by 2,070.1km of various lines, i.e., subway lines(241km), private lines(952.7km), JR lines(876.4km), provides convenient means of transportation for the coummuters and makes a contribution to the development of its neighboring areas and to the expansion of settlement areas. Comparing the total length per 1,000$\textrm{km}^2$, Tokyo(105), Paris(117), and London(115) are at least 6 times as large as ours(15). The purpose of this study is two fold provide a basic scheme for building railroads in metropolytan area and determine priority order in accordance with some evaluation criteria.

• International Journal of Contents
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• 제15권3호
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• pp.47-54
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• 2019

The purpose of this study is to explore the factors affecting the community well-being of residents through empirical analysis. Rather than just identifying the variables that promote residents' subjective happiness, we focused on factors affecting residents' living condition. In order to empirically investigate the influencing factors, we constructed the analysis data using the Gyeonggi-do survey. We analyzed it by using linear regression analysis. Through the effects of influencing factor analyzed, we could find implications for public project's priority in budget distribution. It could be suggested that local public projects for residents should be focused on improving programs such as job satisfaction, resident health, and neighborhood relations in order to effectively raise community well-being level.

• 한국시뮬레이션학회:학술대회논문집
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• 한국시뮬레이션학회 1997년도 춘계 학술대회 발표집
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• pp.93-99
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• 1997

Most of the past studies on FMS scheduling problems may be classified into two classes, namely off-line scheduling and on-line scheduling approach. The off-line scheduling methods are used mostly for FMS planning purposes and may not be useful real time control of FMSs, because it generates solutions only after a relatively long period of time. The on-line scheduling methods are used extensively for dynamic real-time control of FMSs although the performance of on-line scheduling algorithms tends vary dramatically depending on various configurations of FMS. Current study is about finding a better on-line scheduling rules for FMS operations. In this study, we propose a method to create priority functions that can be used in setting relative priorities among jobs or machines in on-line scheduling. The priority functions reflect the configuration of FMS and the user-defined objective functions. The priority functions are generated from diverse dispatching rules which may be considered a special priority functions by themselves, and used to determine the order of processing and transporting parts. Overall system of our work consists of two modules, the Priority Function Evolution Module (PFEM) and the FMS Simulation Module (FMSSM). The PFEM generates new priority functions using input variables from a terminal set and primitive functions from a function set by genetic programming. And the FMSSM evaluates each priority function by a simulation methodology. Based on these evaluated values, the PFEM creates new priority functions by using crossover, mutation operation and probabilistic selection. These processes are iteratively applied until the termination criteria are satisfied. We considered various configurations and objective functions of FMSs in our study, and we seek a workable solution rather than an optimum or near optimum solution in scheduling FMS operations in real time. To verify the viability of our approach, experimental results of our model on real FMS are included.

• 정보처리학회논문지A
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• 제17A권4호
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• pp.167-172
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• 2010

본 논문에서는 우선순위 큐에 대한 성능 시험 모델을 제안하고, 제안된 모델에 따라 대표적인 우선순위 큐인 전통 힙, 후순위 힙, 및 페어링 힙의 성능 시험 결과를 보여준다. 이들 중 전통 힙이 분석된 시간복잡도에 있어서 최악인 것으로 알려져 있다. 그러나 제안된 성능 시험 모델에 근거한 성능 시험 결과에 따르면, 포인터를 사용하는 페어링 힙이 가장 느리고 전통 힙이 가장 빠른 것으로 나타났다. 두 묵시 힙에 대해서도, 분석된 시간복잡도로는 후순위 힙이 전통 힙보다 우수하지만, 성능 시험 결과는 반대인 것으로 나타났다.

• Environmental Analysis Health and Toxicology
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• 제14권4호
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• pp.165-174
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• 1999

This study was conducted to analyze the priority of environmental problems in Korea by investigating the environmental professionals' perception. The delphi technique was applied to identify their risk perception towards some specific items related with pollution. A standardized questionnaire on environmental problems and their priorities was used to 74 subjects. In the questionnaire, the environmental problems were divided into the general ones,9 items, and the specific ones,30 items. Also, the perception was associated with two points of view which were the risk on general human health or ecosystem, and on the present situation in Korea. The priority of risk from general environmental problems on human health or ecosystem was analyzed in the order of 'water pollution', 'air pollution', 'soil contamination', 'waste', 'toxic chemical pollutants', 'food contamination', 'ocean contamination', 'odor pollution', and 'noise pollution'. The priority of risk on the present situation in Korea was analyzed in the order of 'water pollution','air pollution','waste','toxic chemical pollutants','food contamination','soil contamination','ocean contamination','odor pollution', and 'noise pollution'. And these priorities were significantly related with the characteristics of respondents such as sex, age, and major concerned area. However, for the first five priorities of risk from the specific environmental problems on human health or ecosystem, the environmental professionals agreed with 'automotive vehicle exhaust', 'domestic and industrial source pollutants to surface water', '$CO_2$nd g1oba1 warming effect','toxic air pollutant' and 'industrial source air pollution'. The priorities of risk on the present situation in Korea were similar to these results.

• Management Science and Financial Engineering
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• 제17권1호
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• pp.79-94
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• 2011

Team orienteering, an extension of single-competitor orienteering, is the problem of determining multiple paths from a starting node to a finishing node for a given allowed time or distance limit fixed for each of the paths with the objective of maximizing the total collected score. Each path is through a subset of nodes, each of which has an associated score. The team orienteering problem has many applications such as home fuel delivery, college football players recruiting, service technicians scheduling, military operations, etc. Unlike existing optimal and heuristic algorithms often leading to heavy computation, this paper suggests two types of priority rule based heuristics-serial and parallel ones-that are especially suitable for practically large-sized problems. In the proposed heuristics, all nodes are listed in an order using a priority rule and then the paths are constructed according to this order. To show the performances of the heuristics, computational experiments were done on the small-to-medium sized benchmark instances and randomly generated large sized test instances, and the results show that some of the heuristics give reasonable quality solutions within very short computation time.

• 한국병원경영학회지
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• 제16권2호
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• pp.78-97
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• 2011

The purpose of this study is to analyze activating factors of medical tourism at Busan, and then decide on priority on the factors. As research methods, this study deduced priority of specialists' opinions by AHP analysis technique through structuralized questionnaire on the medical tourism's factors having been suggested from existing prior studies. The analysis results were same as followings. First, as a result of analysis on the main criteria, relative levels of importance were appeared high such as 'competitiveness', 'policy assistances from the government', 'medical care's infrastructure', and 'connectedness with regions' in order. Second, as a result of integrated results analyzing detailed criteria on the main evaluation standards, relative levels of importance were appeared high such as 'medical quality', 'health-related institution's improvement', 'medical infrastructure', 'medical charge', 'tourism-related institution's improvement', 'convenience', 'medical cooperation possibilities', and 'local industry compliance' in order. In conclusion, it is judged that activation of medical tourism shall be propelled after considering relative levels of importance on many policies or activating factors same as suggested in this study.

• 무역학회지
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• 제47권3호
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• pp.17-35
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• 2022

The Pandemic crisis caused by COVID-19 has raised awareness of the importance of supply chain risk management, such as the control of movement between countries and the simultaneous manufacturing paralysis in the world. Effective risk management within the supply chain of the company is a core competency in the global environment. Therefore, this study quantitatively analyzed the perspective of domestic large corporations and small and medium enterprises (SMEs) by using the hierarchical analysis method (AHP) to identify the factors that should be considered as the priority when establishing supply chain risk management plans for large and small business employees. In order to conduct the study, a survey was conducted on large corporations and small and medium enterprises in Gyeongnam and Busan, and AHP analysis was conducted using Microsoft 365 excel program. In addition, Mann-Whitney U test (independent sample-nonparametric test) was conducted using SPSS/18 version of statistical package program for comparative analysis between groups. As a result, the priority was highly evaluated in the order of financial ability, competitiveness, disaster in the overall priority evaluation. There were statistically significant differences in internal risk and strategic decision making of supply chain between groups. This suggests that fandemics such as COVID-19 can not be predicted, but strategic responses are needed to utilize opportunities expressed in the crisis through supply chain risk management and to increase the competitive advantage of domestic companies even in the crisis.

• 대한토목학회논문집
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• 제30권6D호
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• pp.561-567
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• 2010

현재 다수의 복합환승센터 건설 사업이 추진 중에 있으며, 이때 다수의 유사 사업에 대하여 한정된 투자재원으로 경제적 타당성 분석결과에 따라 투자우선순위를 결정하는 것이 타당한 방법이나, 계량화되지 않는 정책적 사항 등에 대한 고려도 충분히 반영할 필요가 있다. 이에 본 연구는 환승체계 개선을 위한 복합환승센터의 정량적인 지표인 경제성분석과 파급효과 등 정량적 지표와 사업추진의지, 재원조달가능성, 지역의 낙후도 등 정성적인 지표를 결합하여 복합환승센터의 우선순위 평가 방법론을 새로이 정립하였다. 제시된 평가방법을 적용하여 투자우선순위 평가 시 정량적 평가는 이용수요가 타 환승센터에 비해 많은 센터가 높게 평가되었다. 정성적 평가는 현재 사업이 추진되고 있는 복합환승센터에서 사업추진 가능성이 높은 센터에서 우선순위가 높게 평가되었다. 따라서 정량적 평가와 정성적 지표를 동시에 적용하여 분석한 결과 지역 간 형평성을 반영할 수 있었다.