• Korean Management Science Review
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• v.24 no.1
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• pp.25-34
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• 2007

In this study, we consider stationary waiting times in finite-buffer 3-node single-server queues in series with a Poisson arrival process and with either constant or non-overlapping service times. We assume that each node has a finite buffer except for the first node. The explicit expressions of waiting times in all areas of the stochastic system were driven as functions of finite buffer capacities. These explicit forms show that a system sojourn time does not depend on the finite buffer sizes, and also allow one to compute and compare characteristics of stationary waiting times at all areas under two blocking rules communication and manufacturing blocking. The goal of this study is to apply these results to an optimization problem which determines the smallest buffer capacities satisfying predetermined probabilistic constraints on stationary waiting times at all nodes. Numerical examples are also provided.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2005.04a
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• pp.161-165
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• 2005

In order to produce an optimal traffic cycle. We must first check how many waiting cars are at the lower intersection, because waiting queue is bigger than the length of upper traffic intersection. Start up delay time and vehicle waiting time occurs. To reduce vehicle waiting time, in this paper, we present an optimal green time algorithm using fuzzy neural network. Through computer simulation has been proven to be improved average vehicle speed than fixed traffic signal light which do not consider different intersection conditions.

• Journal of Korean Institute of Industrial Engineers
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• v.22 no.3
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• pp.313-324
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• 1996

A new policy to determine the waiting position of an idle Automated Guided Vehicle(AGV) is proposed and its performance is compared with the existing waiting position policies. Unlike the existing policies, the queue length in the input buffer is considered in the new policy. As a result, the waiting position based on the new policy depends on the status of the system. The simulation result indicates that the proposed policy reduces the waiting time in both the input and the output buffers significantly, regardless of the number of AGVs in the system. Therefore, the manufacturing lead time can be minimized.

• Journal of Industrial Technology
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• v.18
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• pp.355-362
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• 1998

The deadlock detector is a DBMS sub-component that examines periodically whether system is in a deadlock state based on lock waiting information of transactions. The deadlock detector and transactions execute concurrently in a DBMS and read and/or write the lock waiting information simultaneously. Since the lock waiting information is a shared one, we need an efficient method guaranteeing its physical consistency by using mutual exclusion. In this paper, we propose a new method that effectively guarantees physical consistency of lock waiting information. Two primary goals of our method is to minimize the processing overhead and to maximize system concurrency.

• Korean Institute of Interior Design Journal
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• no.29
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• pp.203-210
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• 2001

Major companies have launched into the film industry since 1990s, which resulted in competition in facilities. In addition, restriction for the number of the prints was removed. Under these circumstances, the cinema has been transformed and developed from the established one-hall cinema into multiplex cinema with large-scaled halls. Contrary to the established cinema, modern cinema are a cultural place within easy access. They accommodate diverse social and cultural needs and their functions have been extending gradually. The waiting areas should not function only as the waiting space for the audience but also the places to attract the audience and provide them with various cultural and art information, and temporary restful break. For this study, the inter-relationship between the structure of the area and the audience are identified objectively by analyzing audience distribution and their routes within the area. The purpose of the study is to provide basic data about the design of the waiting area based on the findings above.

• Journal of Korean Institute of Industrial Engineers
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• v.24 no.4
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• pp.639-647
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• 1998

We consider a multiclass production system processed by a single machine with cyclic order. Each part belongs to one of several classes and arrives at each queue in a Poisson process. The processing discipline at each queue is either exhaustive or gated. We introduce a new approach to analysis of mean waiting times for each queue. We formulate mean waiting times as cost functions on state of the system. The mean waiting times are obtained by solving a set of O($J^2$) linear equations, where J is the number of queues in the system. We also obtain the mean number of parts of each queue in the system at an arbitrary time. Based on this result, we plot the numerical values of the mean waiting times for several parameter settings.

• The Korean Journal of Applied Statistics
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• v.25 no.6
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• pp.959-975
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• 2012

Each year research institutions such as the Korea Employment Information Service(KEIS), a government institution established for the advancement of employment support services, and Job Korea, a popular Korean job website, announce first job waiting times after college graduation. This provides useful information understand and resolve youth unemployment problems. However, previous reports deal with the time as a completely observed one and are not appropriate. This paper proposes a new study on first job waiting times after college graduation set to 4 months prior to graduation. In Korea, most college students hunt for jobs before college graduation in addition, the full-fledged job markets also open before graduation. In this case the exact waiting time of college graduates can be right-censored. We apply a Cox proportional hazards model to evaluate the associations between first job waiting times and risk factors. A real example is based on the 2008 Graduates Occupational Mobility Survey(GOMS).

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.12
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• pp.8820-8829
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• 2015

While medical services are recognized to be crucial in a process of disease treatment, the research has been done with the service space and waiting time in a medical institution. This paper's objective is to evaluate the waiting areas of lobby, outpatient clinic, operating room in a general hospital and to draw factors of architecture design for further improvement, identifying strengths and weaknesses to be analyzed in terms of medical service. Research method is to define concepts of waiting time through literature review and advanced researches, analyze characteristics of architectural plan through drawing analysis and site survey. This research will contribute to the improvements of the planning methods which will reduce the waiting time and increase the quality of medical service.

• Journal of Korea Society of Industrial Information Systems
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• v.23 no.1
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• pp.53-63
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• 2018

In this paper, we analyze the waiting time of a queueing system with D-BMAP (discrete-time batch Markovian arrival process) and D-policy. Customer group or packets arrives at the system according to discrete-time Markovian arrival process, and an idle single server becomes busy when the total service time of waiting customer group exceeds the predetermined workload threshold D. Once the server starts busy period, the server provides service until there is no customer in the system. The steady-state waiting time distribution is derived in the form of a generating function. Mean waiting time is derived as a performance measure. Simulation is also performed for the purpose of verification and validation. Two simple numerical examples are shown.

• Journal of Korean Critical Care Nursing
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• v.8 no.1
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• pp.11-24
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• 2015

Purpose: The purpose of this study was to explore the experience of patients on the waiting list for kidney retransplantation. Methods: The data were collected by individual in-depth interviews of nine patients who were dialyzed after primary kidney graft dysfunction and were waiting for deceased donor kidney retransplantation. All interviews were audio-taped and transcribed, and were analyzed using a phenomenological method. Results: The findings included 5 theme clusters and 13 sub-themes. The 5 clusters were 'Diagnosed with chronic renal failure and dialysis: Broken daily life and crisis', 'Kidney transplantation: The only way to escape from dialysis', 'Kidney graft failure: Inevitable moving backward to hemodialysis', 'Self-management of re-dialysis patients: Growth through pain', and 'The waiting for kidney retransplantation: To try again in the hope of getting a new life'. Conclusion: This study provides a deep understanding of patients with dialysis who are waiting for deceased donor kidney retransplantation. On the basis of the findings of this study, health professionals can provide customized information and develop effective nursing interventions to improve the self-management of these patients.