• Journal of applied mathematics & informatics
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• v.28 no.1_2
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• pp.275-282
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• 2010

This paper analyzes a discrete-time bulk-service queue with probabilistic bulk size, where the service process is interrupted by a Markov chain. We study the joint probability generating function of system occupancy and the state of the Markov chain. We derive several performance measures of interest, including average system occupancy and delay distribution.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2016.05a
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• pp.151-152
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• 2016

Various studies on Port and Terminal have been conducted to gain the competitive advantage, but they are limited to the bulk terminal than container terminal. Therefore, the study is to analyze the service quality of bulk terminal. The study first finds attributes of bulk terminals through professional groups and brainstorm. This study analyzes the difference between the perception of the actors such as carriers, forwarders and shippers, using a bulk terminal. The result shows that all service quality factors have a significant effect on the satisfaction.

• Journal of Communications and Networks
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• v.7 no.1
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• pp.87-92
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• 2005

This paper presents basic queueing analysis contributing to teletraffc theory, with commonly accessible mathematical tools. This paper studies queueing systems with bulk arrivals. It is assumed that the number of arrivals and the expected number of arrivals in each bulk are bounded by some constraints B and (equation omitted), respectively. Subject to these constraints, convexity argument is used to show that the bulk-size probability distribution that results in the worst mean queue performance is an extremal distribution with support {1, B} and mean equal to A. Furthermore, from the viewpoint of security against denial-of-service attacks, this distribution remains the worst even if an adversary were allowed to choose the bulk-size distribution at each arrival instant as a function of past queue lengths; that is, the adversary can produce as bad queueing performance with an open-loop strategy as with any closed-loop strategy. These results are proven for an arbitrary arrival process with bulk arrivals and a general service model.

• Korean Journal of Veterinary Service
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• v.42 no.4
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• pp.177-181
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• 2019

Q fever is a zoonosis caused by Coxiella burnetti that is important not only for livestock but also for humans. This research aims to investigate infection rate of Q fever by examining the prevalence of antibody titers in cattle in Sejong City. From March to October 2018, 505 samples of Hanwoo serum and 47 samples of bulk-tank milk were collected and analyzed using ELISA. According to the result, 25 (53.2%) out of 47 bulk-tank milk samples were antibody positive and 28 (5.5%) out of 505 cows were antibody positive. The seroprevalence of C. burnetii increased with age (<1 y=0%, 1~2 y=4.1%, 3~5 y=7.5%, ≥6 y=9.6%) and was higher in females (6.5%) compared to males (0%).

• Journal of the Society of Naval Architects of Korea
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• v.31 no.4
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• pp.8-14
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• 1994

The aim of this paper is the introduction and investigation of the characteristics and outline of self-unloading systems from the bulk handling point of view. Some years of experiences from the building of self-unloading bulk carriers are described hereunder.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.9B
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• pp.783-792
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• 2003

We consider a finite-buffer discrete-time queueing system with fixed-size bulk-service discipline: Geo/ $G^{B}$1/K＋B. The main purpose of this paper is to present a performance analysis of this system that has a wide range of applications in Asynchronous Transfer Mode (ATM) and other related telecommunication systems. For this purpose, we first derive the departure-epoch probabilities based on the embedded Markov chain method. Next, based on simple rate in and rate out argument, we present stable relationships for the steady-state probabilities of the queue length at different epochs: departure, random, and arrival. Finally, based on these relationships, we present various useful performance measures of interest such as the moments of number of packets in the system at three different epochs and the loss probability. The numerical results are presented for a deterministic service-time distribution - a case that has gained importance in recent years.s.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.16 no.28
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• pp.39-47
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• 1993

In this paper, We develop performance evaluation model for Twin fork Automated Storage/Retrieval systems. The system is modeled as a modified bulk service queueing system consisting of one exponential server with limited system capacity. The differance between this model and general bulk service queueing model is the inequality of transition service rate of each stage. The ejective of this model is to provide system characteristics for Twin fork AS/R system design problems, which are the number of customers in system, wait time in system and queue, the system queue size.

• Korean Journal of Veterinary Service
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• v.42 no.2
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• pp.61-65
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• 2019

Seroprevalence of Coxiella burnetii (Q fever) in bulk-tank milk and cattle in Daegu area was analyzed from 2017 to 2018 by ELISA. The prevalence of antibodies in collected bulk-tank milk from 12 dairy cattle farms was 41.7% (10/24) and the seroprevalence of 249 cows reared in the area of Daegu was 3.2% (8/249) By age, the seroprevalence was 1.9% (2/105) in less than 2 years of age, 4.2% (5/119) between 3 and 5 years of age and 4.0% (1/25) in more than 6 years of age. By breed, the seroprevalence of the Hanwoo cattle was 1.2% (2/162) and the seroprevalence of the dairy cattle was 6.9% (6/87). The result suggested that seroprevalence of C. burnetii was relatively high in both bulk-tank milk samples and dairy cattle than the Hanwoo cattle. Based on these data, it is necessary to keep monitoring the prevalence of Q fever in Daegu area.

• Journal of Korean Society of Water and Wastewater
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• v.19 no.4
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• pp.487-496
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• 2005

Chlorine bulk decay tests were carried out by bottle test under controlled conditions in a laboratory. Experiments were performed at different temperatures: $5^{\circ}C$, $15^{\circ}C$, $25^{\circ}C$, and the water temperatures when samples were taken from the effluent just before entering to its distribution system. 38 bulk tests were performed for water of Al (water treatment plant), 4 bulk tests for A2 (large service reservoir), and A3(pumping station). Residual chlorine concentrations in the amber bottles were measured over time till about 100 hours and bulk decay coefficients were evaluated by assuming first-order, parallel first-order, second-order. and $n^{th}-order$ reaction. The $n^{th}-order$ coefficients were obtained using Fourth-order Runge-Kutta Method. A good-fit by the average coefficient of determination ($R^2$) was first-order ($R^2=0.90$) < parallel first-order ($R^2{_{fast}}=0.92$, $R^2{_{slow}}=0.95$) < second-order ($R^2=0.95$) < $n^{th}-order$ ($R^2=0.99$). But if fast reaction of parallel first-order bulk decay were applied to the effluent of large service reservoir with ca. 20 hours of travel time and slow reaction in the water distribution system following the first 20 hours, parallel first-order bulk decay would be best and easy for application of water quality modeling technique.

• Korean Journal of Veterinary Service
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• v.44 no.1
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• pp.11-14
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• 2021

Seroprevalence of Coxiella burnetii in cattle and goats from southern region of Korea was analyzed. From January to December 2020, 1,409 samples of bulk-tank milk, cattle serum and goat serum were collected and analyzed using ELISA. The prevalence of antibodies in collected was 72.6% (501/682), 4.1% (21/515) and 10.4% (22/212). By age, the seroprevalence of cattle was 2.4%, 4.1%, 5.3% (<2 years, 2~5 years, ≥6 years). In bulk-tank milk of dairy cattle according to region was Gyeongnam 45.5%, Gyeongbuk 77.5%, Daegu 70.0%, Jeonnam 50.0% and Chungbuk 50.0%. And seroprevalence of goats was 10.4% (22/212).