• 산업경영시스템학회지
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• 제43권4호
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• pp.1-14
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• 2020

Recently, M/G/1 priority queues with a finite buffer for high-priority customers and an infinite buffer for low-priority customers have applied to the analysis of communication systems with two heterogeneous traffics : delay-sensitive traffic and loss-sensitive traffic. However, these studies are limited to M/G/1 priority queues with finite and infinite buffers under a work-conserving priority discipline such as the nonpreemptive or preemptive resume priority discipline. In many situations, if a service is preempted, then the preempted service should be completely repeated when the server is available for it. This study extends the previous studies to M/G/1 priority queues with finite and infinite buffers under the preemptive repeat-different and preemptive repeat-identical priority disciplines. We derive the loss probability of high-priority customers and the waiting time distributions of high- and low-priority customers. In order to do this, we utilize the delay cycle analysis of finite-buffer M/G/1/K queues, which has been recently developed for the analysis of M/G/1 priority queues with finite and infinite buffers, and combine it with the analysis of the service time structure of a low-priority customer for the preemptive-repeat and preemptive-identical priority disciplines. We also present numerical examples to explore the impact of the size of the finite buffer and the arrival rates and service distributions of both classes on the system performance for various preemptive priority disciplines.

• 한국도로학회논문집
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• 제15권1호
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• pp.135-141
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• 2013

PURPOSES: In this study, as part of an effort to develop HUD for public transit, it is proposed that the decision of order priority of contents which will be disposed to bus drivers through HUD for public transit using AHP(Analytic Hierarchy Process) technique. METHODS: In AHP analysis method brainstorming, factor analysis, hierarchical structuring, and weighting analysis were performed by applying a classical analysis method. RESULTS: By the result of analysis it is shown that unlike car drivers, bus drivers prefer information related to bus intervals, bus stop, and door open and close to information related to vehicle running. Also, bus stop information and bus interval information were ranked as first and second place in order priority of HUD contents for public transit by experts. CONCLUSIONS: This method of selecting order priority of HUD contents for public transit can provide a basic foundation for selecting order priority of traffic information contents as well as other HUD contents.

• 한국IT서비스학회지
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• 제16권1호
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• pp.41-53
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• 2017

Recently, due to the economic recession and increase of ITO (IT Outsourcing), bidding in software industry has been recognized as more competitive and the importance of software bid evaluation for corporate selection is being increased. This study aims to analyze and prioritize influential factors in the software bid evaluation criteria which is adopted as the main evaluation model of national software businesses by Ministry of Science. The priority was developed by AHP (Analytic Hierarchy Process) through pair-wise comparison. For the analysis, this study developed analysis model for AHP and conducted survey of experts who have work experience for more than 10 years in the IT industry. As the result of analysis, weighted factors in the evaluation criteria were deduced and differences of priority factors between purchaser and bidder were investigated. The analysis showed differences of view point in the bidding process. With these results, this study suggests how to write a proposal strategically and effectively in perspective of the purchaser. It is expected that priority factors will be adopted in strategic proposals in both bidder and purchaser. For purchaser, the priority will be adopted to select reliable bidder. So, we expect that the priority factors will be used to get more values for both bidder and purchaser in their business atmosphere.

• 기술혁신연구
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• 제13권1호
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• pp.25-54
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• 2005

In this study, priority setting model of new promising IT industries which will be the growth engines for the Korean IT industry, was established. Based on the AHP model, priority setting of IT new promising IT industries was conducted. Firstly, the selection cases of the new promising IT industries and major priority setting methodologies including the AHP methodology, were analyzed. The AHP model was selected as the most feasible methodology for priority setting of the new IT industries, among the various priority setting methodologies. Secondly, in setting up the AHP model for prioritization of the new promising If industries, a 'goal' was established to be priority setting of the new promising IT industries, and an 'alternatives' to be 18 new promising IT industries. Then a logical and a systematic assessment criteria including 5 main criteria('Technological Innovation', 'Market Ability', 'SPin-off Effect', 'Public Benefit', 'Strategic Importance') and 14 sub-criteria, were developed for priority setting of the 18 new promising industries. Finally, with the AHP model, the substantial analysis was made to set up priority of the 18 new promising IT industries. The substantial analysis showed the following priority setting results and implications for the 18 new promising IT industries.

• 산업경영시스템학회지
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• 제35권4호
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• pp.162-170
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• 2012

We propose a new priority discipline called the strict T-preemptive priority discipline, and derive the waiting time distributions of each class in the strict T-preemptive priority M/G/1 queue. Using this queueing analysis, we evaluate the performance of an opportunistic spectrum access in cognitive radio networks, where a communication channel is divided into time slots, a licensed primary user is assigned to one channel, and multiple unlicensed secondary users may opportunistically exploit time slots unused by the primary user. We also present a numerical example of the analysis of the opportunistic spectrum access where the arrival rates and service times distributions of each users are identical.

• 농촌계획
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• 제25권3호
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• pp.89-102
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• 2019

This study was conducted to investigate priority recognition of experts and related facility operators in establishing policies for revitalizing agro-healing services. After reviewing related studies, 5 policy division and 19 detailed sector were drawn, including improving accessibility, improving promotion and information provision method, improved public relations and information provision, diversification of facility and program, financial support, and expansion of expert and specialized institutions. A questionnaire survey was conducted on agro-healing experts, agro-healing facility operators, social welfare experts, and social welfare facility operators. The AHP analysis indicated that agro-healing experts and facility operators had the highest priority in the division of expansion of expert and specialized institutions, while social welfare experts and facility operators had the highest priority in financial support. The IPA analysis was conducted to identify the priority of each policy sector. Respondents recognized above normal importance to policy divisions, but were relatively aware of the importance of improving accessibility, with overall satisfaction level appearing to be moderate. The results of this study are expected to provide useful information for establishing agro-healing policies and for establishing effective strategies.

• 산업경영시스템학회지
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• 제40권3호
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• pp.66-75
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• 2017

Priority disciplines are an important scheme for service systems to differentiate their services for different classes of customers. (N, n)-preemptive priority disciplines enable system engineers to fine-tune the performances of different classes of customers arriving to the system. Due to this virtue of controllability, (N, n)-preemptive priority queueing models can be applied to various types of systems in which the service performances of different classes of customers need to be adjusted for a complex objective. In this paper, we extend the existing (N, n)-preemptive resume and (N, n)-preemptive repeat-identical priority queueing models to the (N, n)-preemptive repeat-different priority queueing model. We derive the queue-length distributions in the M/G/1 queueing model with two classes of customers, under the (N, n)-preemptive repeat-different priority discipline. In order to derive the queue-length distributions, we employ an analysis of the effective service time of a low-priority customer, a delay cycle analysis, and a joint transformation method. We then derive the first and second moments of the queue lengths of high- and low-priority customers. We also present a numerical example for the first and second moments of the queue length of high- and low-priority customers. Through doing this, we show that, under the (N, n)-preemptive repeat-different priority discipline, the first and second moments of customers with high priority are bounded by some upper bounds, regardless of the service characteristics of customers with low priority. This property may help system engineers design such service systems that guarantee the mean and variance of delay for primary users under a certain bounds, when preempted services have to be restarted with another service time resampled from the same service time distribution.

• 대한토목학회논문집
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• 제44권3호
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• pp.417-423
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• 2024

This study compared and analyzed the importance of command priority between railway traffic controllers through pairwise comparison of AHP analysis. 27 railway traffic controllers working on metropolitan railway control center, urban railway control center, and unmanned driving control center responded. As a result of the analysis, all the railway traffic controllers generally recognized the train driving control and train signal control as the most important priorities. For the controller in the manned driving system, a train driving control was the highest at 0.375. On the other hand, the controller based on unmanned driving recognized train signal control as the highest priority at 0.469. In the result of the AHP analysis considering all the variables, the braking system was the highest priority at 0.19 based on manned train driving. On the other hand, the controller based on unmanned train driving recognized wired and wireless network systems and SCADA as the highest priority at 0.267.

• 설비공학논문집
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• 제17권2호
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• pp.156-164
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• 2005

A comparative analysis of an ice storage system has been performed on the operation cost for the four control strategies, i.e., chiller priority and chiller downstream, chiller priority and chiller upstream, storage priority and chiller upstream, storage priority and chiller downstream. Main components of the ice storage system are an ice-on-coil storage tank and a screw compressor chiller. With the simulation program, the operation cost has been evaluated from the economics of an ice storage system. It is found that the operation cost of the ice storage system is strongly dependent on the control strategy, i.e., chiller priority or storage priority, but less affected by the arrangement method, i.e., chiller upstream or chiller downstream. In case of the maximum load day, the control strategy with chiller priority and chiller upstream is supposed to obtain the reduction of operation cost. However, it is found that the control strategy with storage priority and chiller downstream is the best economical operation for most summer seasons except the maximum load day.

• 한국통신학회논문지
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• 제18권8호
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• pp.1190-1200
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• 1993

본 연구에서는 입력이 시간 지연에 민감한 트래픽과 손실에 민감한 트래픽으로 이루어진 경우의 우선순위제어기능을 가진 출력버퍼형의 ATM 스위치의 성능을 분석하였다. 손실우선순위제어 메카니즘으로는 부분 버퍼공유 방법을 택했고, 시간우선순위제어 메카니즘으로는 HOL(Head Of Line)우선순위 제어메카니즘을 택했다. 손실에 민감한 트래괵은 포아송 프로세스로 모델링하였고 시간 지연에 민간한 트래픽은 MMPP로 모델링하였다. 손실우선순위제어에서는 손실우선순위제어 메카니즘을 사용할때 손실에 민간한 트래픽의 셀손실률이 감소함을 확인하였고, 시간우선순위제어에서는 HOL 우선순위제어 메카니즘을 사용할때 시간 지연에 민감한 트래픽의 평균 시간지연이 간소함도 확인하였다. 이 결과로부터 시간우선순위제어와 손실우선순위제어를 동시에 사용하면 시간 지연에 민감한 트래괵과 손실에 민감한 트래픽의 서비스질을 동시에 만족하게 할 수가 있다는 것을 확인하였다.