• Korean Journal of Plant Taxonomy
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• v.53 no.1
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• pp.1-8
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• 2023

Sustainable habitats play a significant role in determining the survival and habitat preservation of endangered species. To conserve the endangered species Iris dichotoma Pall. and its habitat in Taeanhaean National Park, we collected seeds from a natural population and germinated and propagated them in a greenhouse. In 2019, the propagated individuals of I. dichotoma were transplanted at two study sites in Taeanhaean National Park. After conservation translocation, annual monitoring was conducted from 2020 to 2022, and factors related to the survival and growth of I. dichotoma (clonal propagation rate [%], the flowering rate [%], the population density [individual/m²], the maximum leaf bundle length [height; cm], the maximum leaf bundle width [cm], and the pedicel length [cm]) were measured. According to the results of the monitoring of the flowering and fruiting periods for three years after transplantation, 82.4% of individuals in total were found to have survived. During 2020 to 2022, the mean population density (individual/m²) increased from 0.36 to 0.42 and the size of the leaf bundle length and the width both decreased compared to the corresponding figures in 2019 (p < 0.05). According to the findings here, the transplanted population of I. dichotoma is considered to have adapted successfully to its new site in Taeanhaean National Park.

• Bulletin of the Korean Mathematical Society
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• v.43 no.2
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• pp.277-292
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• 2006

We consider a single-server queue with service time distribution of phase type where positive customers, negative customers and disasters arrive according to a Markovian arrival process with marked transitions (MMAP). We derive simple formulae for the stationary queue length distributions. The Laplace-Stieltjes transforms (LST's) of the sojourn time distributions under the combinations of removal policies and service disciplines are also obtained by using the absorption time distribution of a Markov chain.

• Communications of the Korean Mathematical Society
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• v.14 no.3
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• pp.611-625
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• 1999

We consider ΜΑΡ/G/ 1 finite capacity queue with mul-tiple thresholds on buffer. The arrival of customers follows a Markov-ian arrival process(MAP). The service time of a customer depends on the queue length at service initiation of the customer. By using the embeded Markov chain method and the supplementary variable method, we obtain the queue length distribution ar departure epochs and at arbitrary epochs. This gives the loss probability and the mean waiting time by Little's law. We also give a simple numerical examples to apply the overload control in packetized networks.

• The Journal of the Korea Contents Association
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• v.3 no.3
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• pp.55-62
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• 2003

In this paper, I proposed a new WRR Cell Scheduling algorithm for improving the problem of existing smoothing scheme. in proposed algorithm, when queue of being service VC in present round is emptied, instead VC that difference between assigned weight and length of present buffer is biggest in all VC service. This result efficiency of bandwidth allocation is increased. And above all real-time traffic is serviced, non-real-time to allocate bandwidth of the remainder multimedia-service is possible. In one cycle, number of serviced average cell is increased. And for many eel serviced, length of total Duffer is decreased.

• Journal of the Korean Operations Research and Management Science Society
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• v.29 no.3
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• pp.63-78
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• 2004

This paper deals with a supplier-managed inventory(SMI) control for a two-echelon supply chain model with a service facility and a single supplier. The service facility is allocated to customers and provides a service using items of inventory that are purchased from the supplier, Assuming that the supplier knows the information of customer queue length as well as inventory position in the service facility at the time when it makes a replenishment decision, we identify an optimal replenishment policy which minimizes the total supply chain costs by reflecting these information into the replenishment decision. Numerical analysis demonstrates that the SMI strategy can be more cost-effective when the information of both customer queue length and inventory position is shared than when the information of inventory position only is shared.

• Journal of Preventive Medicine and Public Health
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• v.31 no.4 s.63
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• pp.786-800
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• 1998

This study has attempted to show general characteristics of health centre directors who have served the post of directorship during the last 40 years. Of 3,000 such health centre directors, information on about 2,500 directors was collected. While average length of service for health center directors has increased, that of vacancy period has decreased. Rural areas have a shorter average length of service than the urban area. Rural areas have twice longer length of vacancy period per health center. Kangwon-do has the longest average length of vacancy period since 1980(2.79 months/year), and Daejeon has the shortest length of vacancy period(0.21 months/year). Chung-buk has no physician directors. The civil servant's rank for the directorship has promoted from the fifth level to the fourth level since 1990. A comparison between the physician director & non-physician director was made as follows : first, the proportion of physician directors had maintained rather high before 1980 s; 62.5% in 1963, 78.3% in 1970, 70.4% in 1980. It decreased to 44.1% in 1990 and 47.6% in 1997. Instead, non-physician directors has abruptly increased since 1980s (12.4% in 1980, 55.4% in 1990 and 50.8% in 1997). Second, physician directors mainly locate in the urban area(58.0% in 1997), but non-physician directors mainly in the rural area(67.2% in 1997). Third, since 1980, the average length of service for physician directors and for non-physician directors has become similar. Fourth, the mean age of physician directors is 45.1 years, and that of non-physician directors 55.7 years. The latter is 10 years older than the former.

• Quality Improvement in Health Care
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• v.10 no.1
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• pp.20-27
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• 2003

Background : The doctors' strike was not only a manmade disaster but also a chance to apply a new pattern of emergency medical service for patients. We hope to propose a new pattern of emergency medical service by comparing the patterns of emergency medical service given by resident and staff during the doctors' strike. Methods : We reviewed the medical records of patients who received emergency medical service in the Emergency Department(ED) of Deagu Catholic University Hospital during 3 days a week prior to the residents' strike (July 21-23, 2000) with those of patients receiving emergency medical service during the first 3 days of the residents' strike (July 28-30, 2000). We evaluated the patient's severity, the cause of the ED visit, the performance on the laboratory study, ECG, and radiological study, the disposition, and the length of ED stay. Also, we compared the collected data by presenting doctor and by patient's severity. Results : The staff performed fewer tests admitted fewer emergent and non-emergent patients than the residents. Also, the length of ED stay was shorter in both the emergent (212.76 vs. 321.40 minutes) and the non-emergent groups (117.68 vs. 171.39 minutes) for patients presenting to staff. Conclusion : It is desirable that emergency medical service is given by staff, not by resident.

• Proceedings of the Korean Information Science Society Conference
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• 1999.10c
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• pp.423-426
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• 1999

In offering a statistical end-to-end bandwidth guarantee service, typically called Assured Service, in Differentiated Serviced (Diff-Serv) framework, the biggest issue is its inconsistency. Larger profile TCP flows fail to achieve the guaranteed rate when competing with many smaller profile flows. This phenomenon, which we call "bandwidth skew", stems from the fact that larger profile flows take longer time to recover from the congestion window size backoff after a packet drop. Proposed solutions to this problem, therefore, are focused on modifying the TCP behavior. However, TCP modification is not practicable, mainly due to its large installation base. We look to other mechanisms in the Diff-Serv framework to find more realistic solutions. In particular, we demonstrate that RIO, the de facto standard packet differentiation mechanism used for Assured Service, also contributes to the bandwidth skew. Based on this new finding, we design a modified RIO mechanism called RI+O. RI+O uses OUT queue length in addition to IN and IN+OUT queue length to calculate OUT packet drop probability. We show through extensive simulation that RI+O significantly alleviates the bandwidth skew, expanding the operating regime for Assured Service.d Service.

• Journal of the Korean Society of Safety
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• v.27 no.4
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• pp.38-42
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• 2012

This paper describes electrical fire on residential environment such as apartment and detached house caused by defect of interior wiring. We carried out experimental study on short circuit characteristics by the interior wiring length. We were measured arc current, arc energy and interrupting time of earth leakage current circuit breaker(ELB), when an interior wiring break out short circuit in residential environment. From the experiment results, the longer of the interior wiring, the magnitude of arc current decreased and the interrupting time of ELB increased. When applied the A maker's ELB, the strength of arc current and interrupting time of ELB was 254 A and 245 ms respectively at 30 m interior wiring length. In 3 m interior wiring length, arc current and interrupting time was 716 A and 4.24 ms respectively. Arc energy was dependent on the magnitude of arc current and the interrupting time of ELB, the longer the interrupting time, arc energy increasing. In this paper, minimum arc energy was 277 J using C maker's ELB and 3 m interior wiring length(arc current 283 A, interrupting time of breaker 6.28 ms). Therefore in the residential environment, short circuit caused by defect of the interior wiring lead to electrical fire.

• Journal of the Korea Society for Simulation
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• v.27 no.3
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• pp.45-52
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• 2018

We consider the busy period of an M/G/1/K queueing system with queue-length-dependent overload control policy. A variant of an oscillating control strategy that was recently analyzed by Choi and Kim (2016) is considered: two threshold values, $L_1({\leq_-}L_2)$ and $L_2({\leq_-}K)$, are assumed, and service rate and arrival rate are adjusted depending on the queue length to alleviate congestion. We investigate the busy period of an M/G/1/K queue with two overload control policies, and present the formulae to obtain the expected length of a busy period for each control policy. Based on the numerical examples, we conclude that the variability and expected value of the service time distribution have the most influence on the length of a busy period.