• Journal of the Korean Statistical Society
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• v.28 no.1
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• pp.125-133
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• 1999

We consider a FIFO single-server queueing model in which both the arrival and service processes are modulated by the amount of work in the system. The arrival process is a non-homogeneous Poisson process(NHPP) modulated by work, that is, with an intensity that depends on the work in the system. Each customer brings a job consisting of an exponentially distributed amount of work to be processed. The server processes the work at various service rates which also depend on the work in the system. Under the stability conditions obtained by Browne and Sigman(1992) we derive the exact stationary distribution of the work W(t) and the first exit probability that the work level b is exceeded before the work level a is reached, starting from x$\in$[a, b].

• Proceedings of the Korean Geotechical Society Conference
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• 2002.10a
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• pp.507-512
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• 2002

Generally gneiss regions catagolized as metamorphic ground are very complicated and difficult for geotenical engineer to establish stability, this slopes include falt zone and many folding structures. therefore the slope in this study is very complicated and highly wheathered and framentation conditions are irregular by this study, we hope that geotechical engineers who are confronted with the same complicated slope as this slope are doing his job easily and they know which system are adequate to establish the slope stability in large-scale slope with complicated geological structure, and besides through our work flow and modeling process, we hope that our study can be useful for geotenical engineer who may work slope design and construct in complicated ground.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.11a
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• pp.100-101
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• 2018

Environmental problems caused by air pollution have been considered as serious critical issues in global perspectives. Controlling greenhouse gases has become one of the major environmental problems in construction fields as well. However, similar studies were mainly focused on suggestion of various methodologies for measuring CO₂ emissions of construction equipment and calculating emissions. This study aims to analyze the correlation between the CO₂ emissions and RPMs of equipment by the construction process based on row data collected from construction equipment actually operated in job sites. This study allows site personnels to determine the amount of emitted CO₂ under particular construction equipment under specific conditions during the targeted construction operations. The research findings expect to be used as fundamental informations for establishing environment-friendly construction operation planning.

• Journal of Institute of Control, Robotics and Systems
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• v.11 no.4
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• pp.344-352
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• 2005

The modem production systems are required to produce many items. This is due to the fact that society has become more complex and the customers' demands have become more varied. The demand for complex production systems of various purposes, which can flexibly change the content of work, has increased. One of such production systems is FMS (Flexible Manufacturing System). Limited resources must be used in FMS when a number of working procedures are simultaneously being undertaken because the conditions of stand-by job processes cannot be changed. Researchers are currently being conducted to determine ways of preventing deadlocks. In this study, we proposes the algorithm for detection and recovery of a deadlock status using the DDAPN(Deadlock Detection Avoidance Petri Net). Also, we apply the proposed algorithm has a feature to the FMS.

• Journal of the Korean Institute of Educational Facilities
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• v.11 no.3
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• pp.5-15
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• 2004

This study aims to review the reality of local educational officials in technical post, to investigate their needs and awareness for newly changing social environment, and to inspire them with alternatives and strategies for reforming and restructuring their organization. It examines and analyses the strong points and weak points of the organization, the methods for improving the operation systems and organizational structures and the problems in the personnel management in officialdom, especially unfairness between the executive and the technical officials through a questionnaire and interview. This study ascertains that most of the technical officials consider expert knowledge and experience as their strong point and think the negative image against its group as their weak point for the organizational development. Specially this article indicates that they are not satisfied with the job conditions and want to shift to the official in executive post.

• Journal of Family Resource Management and Policy Review
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• v.15 no.4
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• pp.129-147
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• 2011

The purpose of this study was to explore the mechanism involved in predicting the Quality of Life (QOL) of middle.aged Koreans. The QOL was measured by integrating life satisfaction indicators. To accomplish this, a survey data set was drawn from a convenient sample of 670 individuals during the period of January and February 2011. To differentiate the influences from the different life domains, stepwise multiple regressions were attempted. In our results, the SES indicators, personal mental health, physical health, social capital resources from family as well as job places, perceived local government services, and the current living conditions to determine QOL, explained 55% of the total variance. In conclusion, the results of this study demonstrated the complex mechanisms that explain QOL in terms of ecological predictors.

• Proceedings of the KIEE Conference
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• 1996.07b
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• pp.871-874
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• 1996

It is practically very important in multi-criteria long-tenn IRP process to develop the set of candidate resource plans that meet following two conditions. First, the number of resource plans should not be too large for computer job. Second, the unknown best plan should exist among the set of candidate plans. In this paper, several novel procedures are developed. The main idea of the procedures is the two-stage approach. The first stage is to find the set of feasible resource capacity mixes in given target year(s). And, the second stage is to find the set of alternative paths of resource options for each resource mix determined in the first stage.

• Journal of the Korea Society for Simulation
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• v.1 no.1
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• pp.87-102
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• 1992

This paper presents the development of event-driven system level simulation tool SMPLE(Smpl Extende, an extention fo smpl) and its application to the performance analysis of multiprocessor computer systems. Because of its data structure, it is very difficult to change, expand or add new functions to simulation language smpl implemented by MacDougall. In SMPLE, we change data structure with structure and pointer, add new functions, and enable dynamic memory management. Using new data structure, facilities, and functions added in SMPLE, we simulate job processing of a shared bus multiprocessor system with autonomous hierarchical I/O subsystem. We set system performance contribution of subsystems and units. The impact of disk I/O on system performance is evaluated under vairous conditions of number of processors, processing power, memory access time and disk seek time.

• International conference on construction engineering and project management
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• 2007.03a
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• pp.229-238
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• 2007

This paper presents a study on construction safety in the People Democratic Republic of Laos (PDRL). Fifty workers experienced certain injuries in their construction sites and 15 top managers were interviewed in twenty-six construction projects in Vientiane, the capital of PDRL. Research results show that stepping on and/or striking against objects (48%), struck by falling objects (24%), falling of persons (12%) are major types of construction injuries. The paper stresses that the ignorance of top managers about their crucial role in safety improvement, using safety incentive to raise safety performance, lack of thorough understanding about benefit from labor safety performance, and the willingness to cut off safety performance expenditures is considered as obstructions of safety improvement programs. The survey indicates that physical working conditions, relationship among workers, foremen behaviors and the monthly wage were influencing factors to worker's job satisfaction. The study also highlights afternoon as dominant time that led to a large number of injuries.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.956-961
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• 2009

When construction engineers perform their work in the jobsite, they have to record as-built conditions in the project log (Data Collection). On the other hand, the engineers often have to refer to the construction documents when necessary at the job faces (Data Access). The practice of Data Collection and Data Access in the jobsite can be greatly enhanced by utilizing mobile computing with wireless communications. In this paper, two cases of mobile computing applications for construction field management are presented; Mobile Specifications System and Mobile Data Collection System. The demonstration of the process for developing two mobile applications is the primary purpose of the paper. The problems and issues involved with adopting mobile computing for construction field are also presented. The simple information framework for mobile computing has been also proposed as an outcome of the research. As for development tools, readily available relational database and wireless network have been used. The use of commercial mobile broadband was examined for data communication where local area network is not available.