• Proceedings of the Korean Society for Quality Management Conference
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• 2006.04a
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• pp.14-19
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• 2006

This study examined the effect of waiting in a service queue on the evaluation of service quality focused on its overall process, mediators and moderators The conceptual model of this paper integrates key variables derived from previous studies of consumer waiting behavior. Data obtained from actual customers in service queue at a hospital was used to test the theoretical framework. First, results from the path analysis confirm that negative affect and acceptability of the wait function as mediators in the process that the perceived duration of the wait affects customer's evaluation of overall service quality. Second, the analysis of the data, with the use of moderate regression shows that disconfirmation of wait time expectations, transaction importance, stability of wait time and wait environment work as moderate variables for the relationship between perceived duration of wait and negative affect. For the relationship between perceived wait time and acceptability of the wait, on the other hand, only transaction import ante shows a significant effect as a moderator.

• Journal of Korean Society for Quality Management
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• v.42 no.1
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• pp.71-79
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• 2014

Purpose: The purpose of this study is to develop the methods for evaluating patients' queue environment using decision tree and queueing theory. Methods: This study uses CHAID decision tree and M/G/1 queueing theory to estimate pain point and patients waiting time for medical service. This study translates hospital physical data process to logical process to adapt queueing theory. Results: This study indicates that three nodes of the system has predictable problem with patients waiting time and can be improved by relocating patients to other nodes. Conclusion: This study finds out three seek points of the hospital through decision tree analysis and substitution nodes through the queueing theory. Revealing the hospital patients' queue environment, this study has several limitations such as lack of various case and factors.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2005.05a
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• pp.881-889
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• 2005

In this study, we consider characteristics of waiting times in single-server 3-node tandem queues with a Poisson arrival process, finite buffers and deterministic or non-overlapping service times at each queue. There are three buffers: one at the first node is infinite and the others are finite. The explicit expressions of waiting times in all areas of the systems, which are driven as functions of finite buffer capacities, show that the sojourn time does not depend on the finite buffer capacities and also allow one to compute and compare characteristics of waiting times at all areas of the system under two blocking policies: communication and manufacturing blocking. As an application of these results, moreover, an optimization problem which determines the smallest buffer capacities satisfying predetermined probabilistic constraints on waiting times is considered. Some numerical examples are also provided.

• Communications for Statistical Applications and Methods
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• v.7 no.2
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• pp.489-497
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• 2000

The M/M/1 queue with impatient customers is studied. Impatient customers wait for service only for limited time K/0 and leave the system if their services do not start during that time. Notice that in the analysis of virtual waiting time, the impatient customer can be considered as the customer who enters the system only when his/her waiting time does not exceed K. In this paper, we apply martingale methods to the virtual waiting time and obtain the expected period from origin to the point where the virtual waiting time crosses over K or reaches 0, and the variance of this period. With this results, we obtain the expected busy period of the queue, the distribution, expectation and variance of the number of times the virtual waiting time exceeding level K during a busy period, and the probability of there being no impatient customers in a busy period.

• 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.

• 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).

• KEPCO Journal on Electric Power and Energy
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• v.6 no.1
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• pp.59-64
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• 2020

Scheduling of electric vehicles and optimizing for charging waiting time have been critical. Meanwhile, it is challengeable to exploit the fluctuating data from electric vehicles in real-time. We introduce an optimal routing algorithm and a simulator with electric vehicles obeying the Poisson distribution of the observed information about time, space and energy-demand. Electric vehicle routing is updated in every cycle even it is already set. Also, we suggest an electric vehicle routing algorithm for minimizing total trip time, considering a threshold of the waiting time. Total trip time and charging waiting time are decreased 34.3% and 86.4% respectively, compared to the previous algorithm. It can be applied to the information service of charging stations and utilized as a reservation service.

• Proceedings of the IEEK Conference
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• 2000.07a
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• pp.322-325
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• 2000

In a batch scheduling policy being different from real video system, the requests are not served immediately due to grouping user's requests upon every scheduling points. Such waiting delays by inefficient managements makes an unfair service to users and increases the possibility of higher reneging rates. This paper proposes an adaptive batch scheduling scheme which reduces the average waiting time of user’s requests and reduces the starvation problem for requesters of less popular movies. The proposed scheme selects dynamically multiple videos in given intervals based on the service patterns which reflect the popularity distribution and resource utilizations. Experimental simulation shows that proposed scheme improves about 20-30 percent of average waiting time and reduces significantly the starving requesters comparing with those of conventional methods such as FCFS and MQL.

• Journal of Pharmaceutical Investigation
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• v.23 no.2
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• pp.97-102
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• 1993

Hospital pharmacy services are divided into dispensing affairs for inpatients and outpatients, pharmaceutical service, stock control, intravenous admixture service, drug information service, pharmacokinetic consultation service, education and research work, etc. But among those affairs, dispensing affair for outpatient is perceived as the most important work in Korea, because it is linked directly with hospital service for patients. Therefore, total computer system for dispensing area was adopted from opening point of hospital in 1989 in Asan Medical Center. Utilization of computer system for outpatient dispensing area is as follows; 1) Order communication system of prescription by Total Hospital Information System, 2) Automatic print-out system of direction for use by sticker connected with on-line net work, 3) Use of automatic tablet counting and packaging machines connected with on-line net work. Those computer system resulted in curtailment of pharmacy manpower and shortening of waiting-time for outpatient.

• Journal of Global Scholars of Marketing Science
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• v.12
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• pp.135-154
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• 2003

This study having purpose of promoting the convenience of medical service customer at medical service encounter have tried to know the influence of physical environment, perceived justice, and perceived waiting time to the intention of re-use of medical service through mediating variable such as service Quality evaluation and negative emotion. Particularly, this exploratory study have first tried to know what influence the physical environment and perceived justice have on negative emotion. Findings are; First, the physical environment affect positive influence to service Quality evaluation, and lower the negative emotion. Second, perceived justice have no influence to the service Quality evaluation and negative emotion. Third, the perceived waiting time lower the service Quality and increase the negative emotion. Fourth, the service Quality have positive influence to intention of re-use of medical service. However, the negative emotion have no influence to the intention of re-use of medical service. Therefore physical environment of medical service becomes more important and it is necessary to shorten the waiting time. In addition, even though negative emotion have no influence to the intention of re-use of medical service it is necessary to make the smallest of negative emotion. Because it is possible to separate once switching barner due to the medical service specificity is solved.