• Journal of the Korea Society for Simulation
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• v.8 no.3
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• pp.77-89
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• 1999

Simulating rare events, such as probability of cell loss in ATM networks, machine failure in highly reliable systems, requires huge simulation efforts due to the low chance of occurrence. Importance Sampling (IS) has been applied to accelerate the occurrence of rare events. However, it has a drawback of effective biasing scheme to make the estimator of IS unbiased. Adaptive Importance Sampling (AIS) employs an estimated sampling distribution of IS to the system of interest during the course of simulation. We propose Nonparametric Adaptive Importance Sampling (NAIS) technique which is nonparametrical version of AIS. We test NAIS to estimate a probability of rare event in M/M/1 queueing model. Comparing with classical Monte Carlo simulation, the computational efficiency and variance reductions gained via NAIS are substantial. A possible extension of NAIS regarding with random number generation is also discussed.

• Journal of the Korean Society of Industry Convergence
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• v.21 no.6
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• pp.317-327
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• 2018

The perception of earthquake in Korea has changed due to the earthquake that occurred in Gyeongju and Pohang, and the earthquake has become an important factor in infrastructure management. Damage to infrastructures in the event of an earthquake is extensive. In particular, damage to infrastructures that perform public function used to spread to the whole area. From the point of view of earthquake disaster prevention, it is very important for the public to define what infrastructures are important management targets and to prepare a countermeasure. In this study, we propose a method to evaluate the importance of infrastructure to effectively manage infrastructures for earthquakes. For this purpose, important factors for the railway bridges, power generation and electric power facilities, and apartment complexes are suggested. AHP analysis is conducted to suggest priorities. In addition, the evaluation criteria for infrastructure importance are presented.

• Journal of Information Technology Services
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• v.8 no.3
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• pp.83-100
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• 2009

Even though the success of the information system (IS) protect becomes a critical issue to an enterprise and there has been a lot of research about finding critical success factors of IS projects, the scope management for the success of IS protect has received little attention in the literature. The purpose of this research is to investigate the effects of the project scope management activities defined by PMI (Project Management Institute) on the performance of the information system project. The focus of this paper is on the project supplier's point of view. This study shows the priority of the scope management activities during the IS Project. The results show the different results depending on the types of the project clients and the project scale. This research reveals that the scope verification is important for the project supplier from the project process view, and that the scope planning/definition is important for the protect client from the project result view. It also shows different results comparing to the conventional recognition about project success. The research results show that the positive relationships between the project scale and the importance of scope management activities, and between the familiarity of suppliers and clients and the importance of the scope management activities. Through this research, we expect that the importance of the scope management in a project will be considered as an important issue, and that this research will lead to various detailed research about this issue.

• Journal of the Korean Institute of Landscape Architecture
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• v.30 no.3
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• pp.1-11
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• 2002

The purpose of this study is to construct an evaluation criteria based on the relative importance and various combinations of each evaluation index and then to appraise urban biotope in terms of nature experience and recreation. After the standard of evaluation had been developed through the review of existing literature, the relative importance of the evaluation index through expert survey was determined, and the evaluation model to assess biotope value was established. The results of this study are as follows; 1) We have constructed the seventeen evaluation criteria through literature reviews, and have provided relative importance to each evaluation index of the natural in biotope, the diversity of landscape patterns, the appearance-existence of water space, the special landscape elements, and the access based on the results of expert survey. and then we have constructed an evaluation system using the relative importance criteria. 2) To evaluate urban biotope using the evaluation system constructed, we selected 14 sites. The final evaluation results of each site is as follows; The first grade areas are the water space with semi-natural style in front of Gangchon Woobang apartments, the forest zone near Page Temple at Mt. Palgong, the edge area of Jisan and Gosan and the tendril yard against Anshim middle school. The second grade areas are Hyomyung elementary school, the farm land behind the third Anshim Jugong apartment, Ehyun put and the swampy land in front of the Kangchon and Anshim construction site. The third grade areas are Seohan and Hwasung high-rise apartments at Beummul-Dong, the Korea Manpower Agency in the Sungseo industrial zone, and the adjacent area of St. Tongil. The only fourth grade area is the commercial zone near Taegu Department Store. 3) It is highly useful to evaluate urban biotope using the evaluation criteria constructed for this research, the evaluation criteria we developed may be difficult to encompass all expert opinion and the period of space-formation is difficult to estimate urban biotopes. In the future, it is necessary to gather the basic data suitable to estimate biotope and it is necessary to develop detailed evaluation criteria applicable to estimate every biotope that has specific property.

• Journal of the Korean Institute of Landscape Architecture
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• v.29 no.1
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• pp.100-112
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• 2001

The purpose of this study is to construct the evaluation criteria based on the relative importance and various combination of each evaluation index and then to evaluate urban biotope in terms of conservation of species and habitat. After the standard of evaluation had been developed through the literature review, the relative importance of the evaluation index through expert survey was found out, and the evaluation model of biotope value has been established. The results of this study are as follows; 1) We have constructed the nineteen evaluation criteria through literature reviews, and have provided relative importance to each evaluation index of the diversity of typical species in biotope, afforestation rate, stratification, Hemeroby grads, and the diversity of landscape patterns based on the results of expert survey. and then we have constructed the evaluation system using the relative importance criteria. 2) To evluate urban biotope using the evaluation system constructed, we selected 14 sites. The final evaluation results of each site is as follows; The III grade areas are Seohan and Hwasung high-rise apartment at Beummul-Dong, Korea Men Power /Agency in Sungs 대 industrial zone, the adjacent area of St. Tongil, and Hyomyung elementary school. The II grade areas are the farm land behind the third Anshim Jugong apartment, and Ehyun park. The I grade areas are swampy land in front of Kangchon and Anshim construction site, water space with semi-natural style in front of Gangchon Woobang apartment, forest zone near page Temple at mt. Palgong, the edge area of Jisan and Gosan, and the tendril yard against Anshim middle school. The only grade IV area is the commercial zone near Taegu Department 3) It is highly useful to evaluate urban biotope using the evaluation criteria constructed for this research, the evaluation criteria we developed may be difficult to guarantee the ability for reproduction and recovery, the appearance-number of the rare and endangered species are difficult to estimate urban biotopes. In the future, it is highly useful to evaluate biotope in terms of conservation of species and habitat through its valuation criteria developed in this research and it is necessary to develop the evaluation criteria applicable to estimation of biotope inventory and reproduction of biotope.

• Management & Information Systems Review
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• v.17
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• pp.263-287
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• 2005

E-business might be characterized by open system through internet, fortification of relationship between the suppliers and customers in chain system of company, the collaboration among partners and the use of IT. For these characteristics, e-business companies are becoming to suffer such burdens as wide spread of global economy, industry deregulation, and the increasing number of new entrants. In this situation, e-business companies should maintain the flexible system to adapt fast changing environment. Information system planning has been the important research area for many years because of its strategic importance. Among various variables, organization and IS context have been researched for making successful ouput of ISP. In this paper, I studied the importance of flexibility in e-business environments. And further I examined the flexibility of IS, organization and ISP methodologies. The forthcoming paper, I expect to investigate the relationship between IS flexibility, organizational flexibility, ISP flexible methodologies and successful ISP.

• Journal of the Korean Society of Systems Engineering
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• v.15 no.2
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• pp.9-16
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• 2019

The most important task in acquiring the weapon system is to determine the required performance and to test & evaluate it. The importance of the weapon system by ROC (Required Operational Capability) is not considered, and system development and test evaluation are carried out. In addition, technical incidental performance is tested on the same basis as ROC in the test evaluation and determined according to the result. Development test and evaluation that evaluates technical ability is very important, but development agency is supervised and performed. In this paper, we propose a method to give weights considering the importance of ROC, a technical incidental performance determination and test procedure, and a improvement plan for the development and operational test & evaluation.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.17 no.5
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• pp.58-63
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• 2018

Recently in weapon systems development, the importance of reliability has been emphasized due to the increase in complexity and the rapid development of key components and components. Accordingly, the importance of lifespan testing is increased. However, lifespan testing to verify the reliability of a system is costly and takes a lot of time. Therefore in this paper, it was demonstrated that the most critical item of a bladder type accumulator is the bladder. Fatigue life is sensitive to temperature and pressure, with temperature having more impact. The fatigue life of the bladder was estimated to be 18,140 hr through fatigue analysis, which satisfies the required life expectancy of 10,000 hr.

• The Korean Journal of Rehabilitation Nursing
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• v.12 no.1
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• pp.30-38
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• 2009

Purpose: The purpose of this study was to compare the rehabilitation nursing services what nurses recognize to be important and what they do in practice of the industrial workers. Method: The subjects were 150 nurses who were working at the industrial hospital. The questionnaire was made up with 43 items about the perception on importance and performance of rehabilitation services. Result: The highest services in the perception on importance and performance subscale were physical and therapeutic services. The highest difference between perception on importance and performance was the social and occupational services. The perception on importance of rehabilitation services had positive correlation with performance. The group take care of general patients had a higher level of perception on importance than the other group, and level of performance had significant difference with age and position. Conclusion: We need to develop the strategy for promoting the performance of services that recognize it will be important services, but not to do. Further study on system for promoting the nurse practitioner who responsible for rehabilitation nursing.

• Korean Journal of Construction Engineering and Management
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• v.9 no.5
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• pp.137-148
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• 2008

Using PMIS(Project Management Information System) plays an important role in systematically planning and effectively managing the complex and large-sized construction projects. In spite of the importance of PMIS, on-site engineers, who are the main users of PMIS, have not used PMIS enthusiastically because PMIS has been evaluated and improved by not the viewpoint of the system users but the viewpoint of system managers and head office manager. Therefore, this study developed an assessment model to evaluate PMIS with the viewpoint of the on-site engineers, so previously developed PMIS can be evaluated by the on-site engineers with importance and satisfaction elements. It is anticipated that the effective use of the developed assessment model might increase the utilization of existing PMIS as well as develop the construction industry.