• ETRI Journal
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• 제42권1호
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• pp.36-45
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• 2020

A priority-based data communication approach, developed by employing cognitive radio capacity for sensor nodes in a wireless terrestrial sensor network (TSN), has been proposed. Data sensed by a sensor node-an unlicensed user-were prioritized, taking sensed data importance into account. For data of equal priority, a first come first serve algorithm was used. Non-preemptive priority scheduling was adopted, in order not to interrupt any ongoing transmissions. Licensed users used a nonpersistent, slotted, carrier sense multiple access (CSMA) technique, while unlicensed sensor nodes used a nonpersistent CSMA technique for lossless data transmission, in an energy-restricted, TSN environment. Depending on the analytical model, the proposed wireless TSN environment was simulated using Riverbed software, and to analyze sensor network performance, delay, energy, and throughput parameters were examined. Evaluating the proposed approach showed that the average delay for sensed, high priority data was significantly reduced, indicating that maximum throughput had been achieved using wireless sensor nodes with cognitive radio capacity.

• 한국환경복원기술학회지
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• 제27권1호
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• pp.17-29
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• 2024

This study was conducted to select the restoration priority of forest damage sites in Gangwon Province. We first identified the status of damaged areas. We then selected restoration evaluation indicators through a literature review. We then set weights for these indicators through expert surveys. We next acquired data that can represent these indicators and spatially mapped them. Finally, we prioritized the restoration target sites by taking the weights. The results of the study showed that disaster sensitivity and ecologicality are important criteria for selecting the restoration priority of damage sites. The analysis showed that damage sites in Doam, Jeongseon, Samcheok and Inje are in urgent need of restoration. The results of this study are significant in that they selected the restoration priority of damage sites in Gangwon Province based on the restoration priority evaluation criteria selected based on expert surveys. However, the priority restoration areas derived from the results of this study are not actually implementing restoration projects at present. Therefore, it is judged that it would be efficient in various aspects to establish the restoration priority area based on scientific analysis techniques and carry out the project for efficient implementation of the restoration project. In this study, it can be pointed out that the priority of restoration of damage sites was derived based on data from the past due to the limitation of data acquisition. However, the fact that the priority restoration area inferred based on past data has been restored over time has improved the reliability of the study by verifying the usefulness of the priority extraction technique. In the future, if the priority of damage sites is extracted by extracting the restoration target area boundary through the latest data based on the methodology applied in this study, it is considered that it will be available as a result that can be applied to the field.

• 한국농공학회논문집
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• 제51권6호
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• pp.63-68
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• 2009

Most of agricultural reservoirs in Korea have no function of flood control except 5% of reservoirs even exposed to natural disaster. In addition, there are increasing needs for the reservoir to guarantee the release of environmental flow to the downstream. Thus, the purpose of this paper is to study the priority decision method for the reservoir redevelopment satisfying both water utilization and flood control. The major scopes of this research are to set up six priority indices and to make needed GIS data for calculating each priority. There is important consideration of obtaining the data or not in deciding the indices. Although the detailed indices is expected to better reflect redevelopment priority but the subjective indices like, 'opinion' and 'landscape' are excluded. From the results, it will enables the six priority indices to really assist in decision redevelopment priority of agricultural reservoirs.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 합동 추계학술대회 논문집 정보 및 제어부문
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• pp.264-267
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• 2002

This paper proposed a effective priority selection algorithm named weighted round-robin algorithm and show the implementation result of DMAC priority selection module using prosed weighted round-robin algorithm. I parameterize timing constraints of each functional module, which decide the effectiveness of system. Proposed weighted round-robin algorithm decide the most effective module for data transmission using parameterize timing constraints and update timing parameter of each module for next transmission module selection. I implement DMAC priority selection module using this weighted round-robin algorithm and can improve the timing effective for data transmission from memory to functional module or one functional module to another functional module.

• 반도체디스플레이기술학회지
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• 제11권4호
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• pp.13-18
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• 2012

The semiconductor equipments generate a lot of data traffic via communication channels for the effective manufacturing processes of semiconductors and for the automation of semiconductor equipments. These data should be sent to a host computer in order to keep in a safe. The IEEE 802.11e specification gives differentiated and distributed access to a wireless communication medium with four access categories. These four access categories use different priority parameters which lead to quality of service in data traffic. In this paper, it is shown that the throughput of data depends upon the priority parameters provided by IEEE802.11e. We implement the usage of priority parameters in the SECS protocol for semiconductor equipments. It is necessary that the data from semiconductor equipments should be classified with certain priority for the effective use of our proposed method. Therefore, our scheme will contribute to improving the performance of the manufacturing processes of semiconductors.

• 한국전기전자재료학회논문지
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• 제31권6호
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• pp.398-402
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• 2018

The following conclusions were obtained after analyzing the data transmission characteristics using two frequencies and studying a system that selects data with a good reception frequency as a priority data. Data transmission and reception using two frequencies were measured at -41 to -51 dBm when the frequency was normal, and data transmitted at 900 MHz was selected as priority data. When priority frequency failure occurred, the frequency reception data of the next rank was automatically adopted, and when the frequency of the next rank was disturbed, the priority frequency search was performed again. The above results show that the use of two frequencies enables more stable data transmission and transmission, and further studies should be continued to expand the transmission and reception distances.

• 정보처리학회논문지A
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• 제16A권3호
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• pp.217-222
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• 2009

우선순위 큐는 스케줄링, 정렬, 유전자 검색과 같은 우선순위에 따른 검색, 최단거리 계산과 같은 응용에 사용될 수 있다. 본 논문에서 제안하는 배열을 이용한 양단 우선순위 큐 자료구조는 삽입과 삭제 연산에 각각 O(1) 전이시간과 O(logn) 시간이 걸린다. 본 저자가 알고 있는 한, 지금까지의 배열을 이용한 양단우선순위 큐 알고리즘은 삽입과 삭제에 모두 O(logn) 시간이 걸린다.

• 한국정보처리학회논문지
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• 제6권11호
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• pp.3131-3139
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• 1999

Satisfying the rigid timing requirements of various real-time activities in real-time systems often requires some special methods to tune the systems run-time behaviors. Unbounded blocking can be caused when a high priority activity cannot preempt a low priority activity. In such situation, it is said that a priority inversion has occurred. The priority inversion is one of the problems which may prevent threads from meeting the deadlines in the real-time systems. It is difficult to remove such priority inversion problems in the kernel at the same time to bound the worst case blocking time for the threads. A thread is a piece of executable code which has access to data and stack. In this paper, a new real-time systems. It is difficult to remove such priority inversion problems in the kernel at the same time to bound the worst case blocking time for the threads. A threads is a piece of executable code which has access to data and stack. In this paper, a new real-time server model, which minimizes the duration of priority inversion, is proposed to reduce the priority inversion problem. The proposed server model provides a framework for building a better server structure, which can not only minimize the duration of the priority inversion, but also reduce the deadline miss ratio of higher priority threads.

• 한국전자통신학회논문지
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• 제13권5호
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• pp.995-1002
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• 2018

우선 순위 기반 MAC프로토콜에서 경쟁이 심한 경쟁접근구간은 더 많은 수의 충돌 및 재전송을 초래할 수 있다. 경쟁접근구간 동안 우선순위가 높은 트래픽은 우선순위가 낮은 트래픽을 지배하여 우선 순위가 낮은 트래픽이 고갈되어 WBAN 처리량, 지연 및 에너지 소비에 악영향을 미친다. 따라서 본 논문에서는 우선 순위가 낮은 트래픽에 대한 공정한 기회를 제공하기 위해 경쟁접근구간에서 경쟁을 줄이는 응급데이터-퍼스트-우선 순위 MAC(: EFP-MAC) 슈퍼 프레임 구조를 제안한다. 시뮬레이션 결과는 제안 된 EFP-MAC이 IEEE 802.15.4 표준에 비해 낮은 에너지 소비, 높은 처리량 및 낮은 대기 시간을 달성함을 보인다.

• ETRI Journal
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• 제39권4호
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• pp.558-569
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• 2017

In this study, a non-preemptive M/G/1 queueing model of a spectrum handoff scheme for cognitive wireless networks is proposed. Because spectrum handoff gives secondary users an opportunity to carry on their transmissions, it is crucially important to determine the actions of primary users. In our queueing model, prioritized data traffic is utilized to meet the requirements of the secondary users. These users' packets are categorized into three different priority classes: urgent, real-time, and non-real time. Urgent data packets have the highest priority, while non-real time data packets have the lowest priority. Riverbed (OPNET) Modeler simulation software was used to simulate both reactive and proactive decision spectrum handoff schemes. The simulation results were consistent with the analytical results obtained under different load and traffic conditions. This study also revealed that the cumulative number of handoffs can be drastically decreased by exploiting priority classes and utilizing a decent spectrum handoff strategy, such as a reactive or proactive decision-based strategy.