• Proceedings of the Korean Information Science Society Conference
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• 2005.11a
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• pp.913-915
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• 2005

실시간 시스템에서는 두 개 이상의 태스크가 공유자원을 사용한다. 이러한 자원에 의해서 높은 우선순위 태스크가 낮은 우선순위 태스크에 의해서 CPU를 점유 당하는 우선순위 역전현상(Priority Inversion)이 발생한다. 우선순위 역전 문제는 실시간 시스템의 스케줄 가능성과 예측성에 심각한 결함을 야기할 수 있다. 이를 해결하기 위해 본 논문에서는 비교적 크기가 작으면서도 실시간 운영체제의 핵심적 특징을 잘 갖추고 있는 $iRTOS^{TM}$ 커널을 사용하였고 우선순위 역전을 해결하기 위해서 Priority Inheritance Protocol을 사용하여 확장된 MuTexS를 구현하였다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.1
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• pp.56-65
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• 1994

As a method to control the congestion, priority mechanism which gives two-level priority to various traffics using CLP bit in cell haeder is carried in ATM network. In this paper, we proposed PBS(partial buffer sharing) mechanism with two threshold for provide three-level priority using CLP bit and Res. bit. By performance analysis proposed mechanism, we knew that provides flexibility to satisfy requirements of various quality of service, compare to existing mechanism with two-level priority.

• The KIPS Transactions:PartA
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• v.11A no.3
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• pp.213-216
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• 2004

Proirity queues(PQ) can be used in applications such as scheduling or sorting. The data structures for PQ can be constructed with or without pointers. The implicit representation without pointers uses less memory space than pointer-based representation. It if shown that a 2-heap, a traditional Implicit PQ based on a binary tree, is slower than an f-heap based on a 8-ary tree. This is because 8-heap utilizes cache memory more efficiently This paper presents a novel fast implicit heap called 8-heap＊ which is easier to implement. Experimental results show that the 8-heap＊ is faster than 8-heap as well as 2-heap.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.7
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• pp.1321-1334
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• 1994

This paper presents the service handling schemes of an intelligent peripheral(IP) which provides the service function as a physical entity in the intelligent network. Four service request handling scheme are compared for and IP which can handle both ordinary requests and prioritized requests on the blocked-call-delayed basis. Delayed requests are assumed to be stored in a finite storage buffer. Scheme-I exclusively allows prioritized requests be stored and to use a fixed number of reserved servers. The other three schemes without reserved servers(Scheme-II.III,and IV) allow both types of requests to be stored and prioritized requests pushout ordinary requests if the buffer is full. For these four schemes, the blocking probabilities and delay distributions of both types of requests are numerically obtained. From the numericall results, the schemes without reserved servers reduce the blocking probability of ordinary requists without a severe penalty on proritized requests. For three schemes without reserved servers, it is noted that prioritized requests should br served on the first-in, first-out basis, and ordinary requests should be served on the last-in, first-out basis.

• Environmental engineer
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• s.48
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• pp.26-27
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• 1990

• Proceedings of the Korean Information Science Society Conference
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• 2004.10c
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• pp.127-129
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• 2004

대부분의 통신망 복구기법에서는 예상되는 손실에 대한 망 복구를 설계한다. 예를 들어 가장 자주 발생하는 단일 링크 손실의 경우에 대하여 100%의 복구를 보장하는 형태이다. 그러나, 예상되지 않은 손실, 즉 다중 링크의 손실과 같은 경우에는 이리 준비된 예비 자원을 가지고는 설계한대로 100% 복구를 수행할 수 없다. 이 경우에는 남아있는 예비 자원을 이용하여 손실된 트래픽의 일부만이라도 복구하여야 한다. 본 논문에서는 두 개의 링크가 동시에 손실된 경우에 트래픽의 우선순위에 기반하여 여러 단계의 계층적인 복구 견고성을 제공하여, 최상위 우선순위의 트래픽에 대해서는 100%에 가까운 복구율을 제공하는 기법을 제안한다. 제안된 기법은 단일 링크의 손실에 대비한 예비 자원만을 할당하여 다중 링크 손실의 경우에도 높은 우선순위의 트래픽에 대하여 복구 견고성을 제공한다는 점에서 그 실효성이 크다.

• The KIPS Transactions:PartC
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• v.10C no.5
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• pp.611-616
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• 2003

Recently, the HFC-CATV network stand in a substructure of superhighway information network. Because of sharing up to 500 of subscribes, the Collision Resolution Algorithm needs in the upstream channel of HFC-CATV network. In order to provide Quality of Service (QoS) to users with real-time data such as voice, video and interactive service, the research of Collision Resolution Algorithm must include an effective priority scheme. In IEEE 802.14, the Collision Resolution Algorithm has high request delay because of static PNA(Priority New Access) slots structure and different priority traffics with the same probability. In order to resolve this problem, this paper proposed dynamic priority collision resolution algorithm with ternary tree algorithm. It has low request delay according to an increase of traffic load because high priority traffic first resolve and new traffic content with different probability. In the result of the simulation, it demonstrated that the proposed algorithm needs lower request delay than that of ternary tree algorithm with static PNA slots structure.

• Journal of Technology Innovation
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• v.19 no.3
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• pp.57-83
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• 2011

We suggested industry-specific priorities of R&D investment with R&D investment elasticity to GDP calculated from the ripple effect of 28 large-sized industry R&D investment, using a Computable General Equilibrium(CGE) Model. Priority orders apply to only 12 industries, because 16 industries with less than 1% of total investment have been excluded. First, R&D investment elasticity to GDP says that priorities are ordered as Basic metal products, Chemicals, drugs and medicines, Food, beverages and tobacco products, Electronic and electrical equipment, Transportation equipment, Precision instruments, Electrictity, gas, steam and water supply, General machinery and equipment, Communications and broadcasting, Construction, Other services, and Real estate and business services. These priorities show the status quo of Korean industry structures well. The GDP growth rate to 2030 year reference equilibrium, which is an auxiliary index, says a similar priority to results from R&D investment elasticity to GDP. In the end, two criteria of priority order can be functioned as a good index for National Science and Technology Commission deciding what industry to invest and what budget to allocate.

• Journal of the Korea Society for Simulation
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• v.28 no.3
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• pp.25-40
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• 2019

Today, container terminals are fiercely competing to attract an increasing number of containers. As a way to improve terminal productivity, this study proposes two dispatching rules for yard truck allocation priorities. First, Multi-Attribute Dispatching Rule(MADR) is an allocation method to calculate the weighted sum of multiple factors affecting container terminal productivity and priority them. Especially, the workload of the quay crane was considered one of the factors to reduce the residence time of the ship. Second, Cycling Dispatching Rule(CDR) is the effective way to increase the number of double cycles that directly affect terminal productivity. To identify the effects of combinations of pooling and dispatching, a comparative experiments was performed on 8 scenarios that combined them. A simulation environment has been developed for experiments and the results have demonstrated that the combination of terminal level pooling and Multi-attribute Dispatching could be an excellent combination in KPIs consisting of GCR and delayed departure of ships, etc.

• The KIPS Transactions:PartC
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• v.9C no.5
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• pp.783-788
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• 2002

Adaptive Cyclic Packet Dropping algorithm (ACPD), and Non-adaptive Cyclic Packet Dropping algorithm (NCPD) are applying stricter drop precedence than that of RIO algorithm. Especially, 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. And we 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 strict drop precedence policy, we get better performance on priority levels. The results show that the proposed 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 RIO and the NCPD algorithm.