• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.10
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• pp.2014-2027
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• 1994

A queueing model with two input streams of different service priorities is studied. Specifically, IBP+BP/D/1 with head-of-line priority is analyzed. IBP and BP stand for Interrupted Bernoulli Process and Bernoulli Process respectively. The BP-stream customers have the higher service priority over the IBP-stream customers. An exact analysis of this priority queue is presented to derive the distributions of the state of the system at steady state, the waiting time distributions for each class of customers, and the interdeparture time distributions. The numerical results of the analysis are presented to show how the various parameters of the low and high priority arrival processes affect the performance of the system.

• Proceedings of the Korean Information Science Society Conference
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• 2002.04a
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• pp.565-567
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• 2002

인터넷과 무선 이동통신 등이 보편화되면서 두 기술을 접목한 WAP (Wireless Application Protocol)[1]이 등장하였으며, 다수의 사용자 요구를 동시에 효율적으로 처리하면서 다양한 무선 단말기로부터 요청을 신속하게 처리할 수 있는 WAP 게이트웨이(gateway)에 대한 연구가 여러 연구 그룹에서 수행되고 있다. 본 논문에서는 Java의 기본적인 서비스인 멀티쓰레드를 이용하고, 컨테이너 유효 리소스의 효율적 관리를 위해 접속 풀링(connection pooling) 기능과 우선순위 큐를 적용하여 WTP (Wireless Transaction Protocol)[2]를 구현한다. 우선순위에 입각하여 구현된 트랜잭션 서비스를 시뮬레이션을 통하여 성능을 분석한다.

• Proceedings of the Korea Multimedia Society Conference
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• 2001.11a
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• pp.6-11
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• 2001

본 논문에서는 서로 다른 공간해 상도를 갖는 두계층 영상부호화대서 하위계층에는 낮은 우선순위로 인하여 제한된 일정부호화율로 부호화하고, 반면에 각 영상의 상위계층에는 우선순위를 높게 하면서 서로간 균등한 화질을 제공하는 대역할당 방법을 제안한다. 이를 위해서 MPEG-2 공간계층적 부호화구조에서 부호화율-왜곡의 관계를 찾고, 실시간으로 상위계층 영상 사이에 균등한 화필을 제공하는 부호화율 제어방법을 제안한다.

• The KIPS Transactions:PartA
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• v.13A no.5 s.102
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• pp.405-412
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• 2006

Real-time operating systems have been used in various computing environments, where a job must be completed in its deadline, with various conditions, such as effective scheduling policies, the minimum of an interrupt delay, and the solutions of priority inversion problems, that should be perfectly satisfied to design and develop optimal real-time operating systems. Up to now, in order to solve priority inversion problems among several those conditions. There have been two representative protocols: basic priority inheritance protocol and priority ceiling emulation protocol. However, these protocols cannot solve complicated priority inversion problems. In this paper, we design a protocol, called recursive priority inheritance (RPI), protocol that effectively solves the complicated priority inversion problems. Our proposed protocol is also implemented in the Linux kernel and is compared with other existing protocols in the aspect of qualitative analysis.

• The KIPS Transactions:PartA
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• v.11A no.7 s.91
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• pp.577-582
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• 2004

Double-ended Proirity queues(DEPQ) can be used in applications such as scheduling or sorting. The data structures for DEPQ can be con-structed with or without pointers. The implicit representation without pointers uses less memory space than pointer-based representation. This paper presents a novel fast implicit heap called 4-deapr$\ast$ which utilizes cache memory efficiently. Experimental results show that the 4-deap$\ast$ is faster than symmetric min-max heap as well as deap.

• The KIPS Transactions:PartA
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• v.17A no.4
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• pp.167-172
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• 2010

This paper proposes a set of runtime test models for priority queues and shows the runtime test results based on the proposed test models for the representative priority queues: the traditional heap, post-order heap, and pairing heap. Among these heaps, the traditional heap is the worst in time complexity analyzed. But, according to our experimental results based on the test models proposed, it is shown that the slowest one is the pairing heap that utilizes pointers and the fastest one is the traditional heap. For the two implicit heaps, these results are in contrary to the fact that the post-order heap is better than the traditional heap in time complexity analyzed.

• Journal of the Korea Computer Industry Society
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• v.4 no.4
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• pp.613-624
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• 2003

This paper proposes a design for efficient and accurate retrieval of similar image subsequences using the multi-dimensional time warping distance as similarity evaluation tool in image sequence database after building of two indexing structures implemented with priority queue and suffix tree respectively. Receiving query image sequence, at first step, the proposed method searches the candidate set of similar image subsequences in priory queue index structure. If it can not get satisfied results, it retrieves another candidate set in suffix tree index structure at second step. The using of the low-bound distance function can remove the dissimilar subsequence without false dismissals during similarity evaluating process between query image sequence and stored sequences in two index structures.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.4
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• pp.782-792
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• 1997

Asynchronous transfer mode (ATM) provides the means to support with variety of multimedia serivices in broadband network. For the support of multimedia services, various data traffic with priortes should be controlled errectively and congestion function is required in the network to carry out the control operation. To accomplish this in a flexible and effective manner, priorty classes for the different services are commonly used. In this paper, we suggested a buffer managment algorithm in ATM network to improve overall network performance with separated buffer which consists of existing buffer with threshold andauxiliary buffer whose input consists of superposition of voice and data traffic. To evaluate the proposed buffer managment algorithms, simulations are excuted with two proiorities and the results are provied that network throughput is improved better than the existing parital buffer method.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.30 no.6
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• pp.452-466
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• 2019

As the spectrum demand increases, securing spectrum resources in a timely manner becomes necessary. This paper proposes a spectrum-band prioritization scheme for establishing an efficient spectrum-use policy. The criteria for spectrum-band prioritization are derived from articles of the Radio Waves Act, and a four-level matrix for priority evaluation is proposed, considering both demand urgency and supply ease. The prioritization processes and items to consider for measuring each criteria are also proposed in order to implement the proposed prioritization scheme. It is expected that the proposed scheme can help secure the spectrum in a timely manner, protect incumbent users properly, and promote new spectrum-based businesses.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.39 no.2
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• pp.59-68
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• 2002

In this paper, we compared and analyzed two new models of cyclic packet dropping algorithm, Adaptive Cyclic Packet Dropping algorithm (ACPD), and Non-adaptive Cyclic Packet Dropping algorithm (NCPD) with RIO. The ACPD algorithm drops adaptively packets for the congestion control, as predicting traffic pattern between each cycle. Therefore the ACPD algorithm makes up for the drawback of RIO algorithm and minimizes the wastes of the bandwidth being capable of predicting in the NCPD algorithm. We modelled two cyclic packet drop algorithms and executed a simulation and analyzed the throughput and packet drop rate based on Sending Priority changing dynamically depending on network traffic. In this algorithm, applying the strict drop precedence policy, we get better performance on priority levels. The results show that two new algorithms may provide more efficient and stricter drop precedence policy as compared to RIO independent of traffic load. The ACPD algorithm can provide better performance on priority levels and keep stricter drop policy than other algorithms.