• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.5
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• pp.995-1002
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• 2018

A Contention Access Period(: CAP) with high contention in priority-based MAC protocols can result in higher number of collisions and retransmissions. High-Priority traffic dominates low-priority traffic during CAP depleting low-priority traffic, adversely affecting WBAN throughput, delay, and energy consumption. This paper proposes a Emergency data-First-Priority MAC(: EFP-MAC) superframe structure that is able to reduce contention in the CAP period, and provides a fair chance for low-priority traffic. As a result, the proposed Emergency data-First Priority MAC(; EFP-MAC) The Simulation results show that the proposed MAC achieves lower energy consumption, higher throughput and low latency than the IEEE 802.15.4 standard.

• Journal of Fisheries and Marine Sciences Education
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• v.18 no.2
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• pp.172-182
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• 2006

The aims of this study is to suggest how the port specialists think the priority of container feeder port development in Korea. To illustrate the ideas regarding a container feeder port development, 56 detailed attributes were identified both from the previous studies and from brainstorming port professionals. And these were grouped into 5 criteria by 'KJ method' and made into 4 levels hierarchy structure. AHP technique identifies the relative weights of each levels and trends of the preference of port specialists from 6 alternatives. As a result, a feeder port development priority in Korea has been proposed.

• Journal of the military operations research society of Korea
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• v.15 no.1
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• pp.44-53
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• 1989

This paper concerns with the case of having a goal program with no preassigned deterministic ranking for the goals. The priority ranking in this case depends on the states of nature which are random variables. The Bayesian approach is performed to obtain the nondominated set of rankings.

• Korean Management Science Review
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• v.19 no.2
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• pp.139-153
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• 2002

The Analytic Hierarchy Process (AHP) is known as a very useful decision-making model developed for obtaining the relative weights of alternatives through pairwise comparison in the context of hierarchical structure. In this paper, we propose a method to reflect the reliability of evaluators in the process of pairwise comparison. This method is applied to the evaluation of aerospace technology alternatives. We have conducted a questionnaire survey for S company that is one of the representative aerospace companies in Korea. A questionnaire was designed for obtaining both the priority with considering the reliability of evaluators' importance weights (the modified AHP priority) and the priority with assuming equally reliable evaluators' importance weights (the AHP priority) in order to compare the priority derived by each of two methods. The result shows that there exists the difference hard to neglect between the final priorities gained by two methods.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.3-4
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• 2006

Fast IP address lookup in routers is essential to achieve packet forwarding in wire-speed. The longest prefix matching for IP address lookup is more complex than exact matching because of its dual dimensions, length and value. By thoroughly studying the current proposals for IP address lookup, we find out that the binary search could be a low-cost solution while providing high performance. Most of the existing binary search algorithms based on trie have simple data structures which can be easily implemented, but they have some problems because of empty internal nodes. The proposed algorithm is based on trie structure, but empty internal nodes are replaced by priority prefixes. The best-matching-prefix search in the proposed algorithm is more efficiently performed since search can be finished earlier when input is matched with a priority prefix. The performance evaluation results show that the constructed priority-trie has very good performance in the lookup speed and the scalability.

• Journal of Korea Multimedia Society
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• v.5 no.3
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• pp.323-330
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• 2002

Recently, the existing embedded real-time operating systems(RTOSs) are being developed in terms of various modified versions in every application fields. Major characteristics and difference of these OSs lie in their distinct development of mechanisms which can be used in various environment and task-scheduling function which can control time-limited contingencies. In this paper, we design and implement round/robin scheduling algorithm based on time-sharing with equal-priority for multiple tasks which are provided preemptive and priority task allocation function in $\mu{C/OS-II}$ version 2.03. We propose the most important event-ready list structure in $\mu{C/OS-II}$; kernel, and provide the running result for multiple tasks with equal priority for the proposed structure.

• Bulletin of the Korean Chemical Society
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• v.31 no.9
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• pp.2717-2720
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• 2010

• Management Science and Financial Engineering
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• v.2 no.1
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• pp.123-145
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• 1996

We consider a priority-based multiclass queue with probabilistic feed-back. There are J service stations. Each customer belongs to one of the several priority classes, and the customers of each class arrive at each station in a Poisson process. A single server serves queued customers on a priority basis with a nonpreemptive scheduling discipline. The customers who complete their services feed back to the system instantaneously and join one of the queues of the stations or depart from the system according to a given probability. In this paper, we propose a new method to simplify the analysis of these queueing systems. By the analysis of busy periods and regenerative processes, we clarify the underlying system structure, and systematically obtain the mean for the sojourn time, i.e., the time from the arrival to the departure from the system, of a customer at every station. The mean for the number of customers queued in each station at an arbitrary time is also obtained simultaneously.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.27 no.4
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• pp.23-30
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• 2013

Reliability Centered Maintenance(RCM) is one of most widely used methods in the modern power system to schedule a maintenance cycle and determine the priority of inspection. A precedence study for the new structure of rearranged system should be performed due to introduction of additional installation. This paper proposes a new method to evaluate the priority of maintenance and inspection of the power system facilities. In order to calculate that risk index, it is required that the reliability block diagram should be analyzed for the power system. Additionally, a fault cause analysis is also performed through the event-tree analysis.

• Journal of the Korea Society of Computer and Information
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• v.22 no.11
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• pp.39-47
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• 2017

In this paper, we propose a message transmission processing structure for efficient use of radio resources. Existing tactical data links have more data and accumulate more data than the amount of tactical data planned according to the situation. This may result in delays in operations and additional problems. To prevent this, priority is assigned to the message and transmission is performed according to the priority on a single basis. And we design a processing structure that can update duplicate messages and delete old messages in order to prevent waste of radio resources. Experiments are conducted to verify that these structures can be implemented and applied to data links.