• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 추계종합학술대회 논문집(2)
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• pp.196-199
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• 2000

In this paper has studied an enhanced usage parameter control algorithm, which is one of the preventive traffic control method in ATM networks. The proposed algorithm is based on the CLP(Cell Loss Priority) bit in the ATM cell header. This algorithm can eliminate the measurement phasing problem in cell conformance testing in ATM networks. The proposed algorithm can minimize the cell loss ratio of high priority cell(CLP = 0) and resolve the burstiness of eel]s which may be generated in the multiplexing and demultiplexing procedure. For the performance evaluation, we have simulated the proposed algorithm with discrete time input traffic model and the results show that the performance of the proposed algorithm is better than that of ITU-T usage parameter control algorithm.

• 전자공학회논문지A
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• 제33A권2호
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• pp.196-204
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• 1996

This paper presents a new scheduling algorithm, which is the most improtant subtask in the high level synthesis. The proposed algorithm performs scheduling in consideration of resource sharing concept based on characteristics of conditionsla bransches in the intermediate data structure. CDFG (control data flow graph) generated by a VHDL analyzer. This algorithm constructs a conditon graph based on time frame of each operation using both the ASAP and the ALAP scheduling algorithm. The conditon priority is obtained from the condition graph constructed from each conditional brance. The determined condition priority implies the sequential order of transforming the CDFG with conditonal branches into the CDFG without conditional branches. To minimize resource cost, the CDFG with conditional branches are transformed into the CDFG without conditonal brancehs according to the condition priority. Considering the data dependency, the hardware constraints, and the data execution time constraints, each operation in the transformed CDFG is assigned ot control steps. Such assigning of unscheduled operations into contorl steps implies the performance of the scheduling in the consecutive movement of operations. The effectiveness of this algorithm is hsown by the experiment for the benchmark circuits.

• ETRI Journal
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• 제24권5호
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• pp.360-372
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• 2002

In this paper, we propose the modified dynamic weighted round robin (MDWRR) cell scheduling algorithm, which guarantees the delay property of real-time traffic and also efficiently transmits non-real-time traffic. The proposed scheduling algorithm is a variation of the dynamic weighted round robin (DWRR) algorithm and guarantees the delay property of real-time traffic by adding a cell transmission procedure based on delay priority. It also uses a threshold to prevent the cell loss of non-real-time traffic that is due to the cell transmission procedure based on delay priority. Though the MDWRR scheduling algorithm may be more complex than the conventional DWRR scheme, considering delay priority minimizes cell delay and decreases the required size of the temporary buffer. The results of our performance study show that the proposed scheduling algorithm has better performance than the conventional DWRR scheme because of the delay guarantee of real-time traffic.

• 제어로봇시스템학회논문지
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• 제8권6호
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• pp.506-513
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• 2002

Distributed control systems(DCS) using fieldbus such as CAN have been applied to process systems but it is very difficult to design the DCS while guaranteeing the given end-to-end constraints such as precedence constraints, time constraints, and periods and priorities of tasks and messages. This paper presents a scheduling method to guarantee the given end-to-end constraints. The presented scheduling method is the integrated one considering both tasks executed in each node and messages transmitted via the network and is designed to be applied to a general DCS that has multiple loops with several types of constraints, where each loop consists of sensor nodes with multiple sensors, actuator nodes with multiple actuators and controller nodes with multiple tasks. An assignment method of the optimal period of each loop and a heuristic assignment rule of each message's priority are proposed and the integrated scheduling method is developed based on them.

• 한국통신학회논문지
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• 제29권2A호
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• pp.187-194
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• 2004

본 논문에서는 우선 순위 기반의 예약 코드 다중 접속 (P-RCMA) 프로토콜을 제안한다. P-PCMA는 기존의 RCMA 프로토콜의 음성 트래픽 성능을 개선한다. P-RCMA는 두 개의 전력 수준을 유지하고 패킷 전송을 위해 공유된 코드를 경쟁하는 시점에 트래픽의 전송 특성을 고려한다. P-RCMA는 기지국 수신 단에서 전력 세기에 따른 캡쳐 효과를 이용하여 데이터 패킷보다는 음성 예약 패킷에 우선순위를 부여한다. 성능 분석은 EPA(equilibrium point analysis) 방법과 시뮬레이션을 이용하고 성능 척도로 음성 패킷 손실 확률 (voice packet dropping probability) 과 평균 데이터 패킷 전송 지연 (average data packet transmission delay)을 사용한다.

• 로봇학회논문지
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• 제1권1호
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• pp.46-57
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• 2006

It is well known that mathematical solutions for multi-agent planning problems are very difficult to obtain due to the complexity of mutual interactions among multi-agent. Most of the past research results thus are based on the probabilistic completeness. However, the practicality and effectiveness of the solution from the probabilistic completeness is significantly reduced by heavy computational burden. In this paper, we propose a practically applicable solution technique for multi-agent planning problems, which assures a reasonable computation time and a real world application for more than 3 multi-agents for the case of general shaped paths in agent movement. First, to reduce the computation time, a collision map is utilized for detecting potential collisions and obtaining collision-free solutions for multi-agents. Second, to minimize the maximum of multi-agent task execution time, a method is developed for selecting an optimal priority order. Simulations are finally provided for more than 20 agents to emphasize the effectiveness of the proposed interactive approach to multi-agent planning problems.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.687-690
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• 2003

This paper presents the development of Programmable Logic Controller (PLC) and network to design the redundant control system in order to control the high priority process. The industrial process that cannot be shutdown or the effect of the shutting down takes abundantly damage. In this article, we say that the high priority process. The redundant systems are designed for controlling the high priority process that the control system must have many controllers to instead the main controller when it has some error. This paper we designed the redundancy control system by the advantage of the high-speed communication on the PLC’s network. The temperature control system and the traffic light control system used as the case study. Each example processes consist of two sets of controller. Our scheme we can increase the reliability prevents process down time and reduces the cost of opportunity to loss also.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2011년도 한국컴퓨터종합학술대회논문집 Vol.38 No.1(B)
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• pp.37-40
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• 2011

리눅스 운영체제는 처리율(throughput)을 보장하는 것을 우선으로 하고 있으며, 태스크들의 응답시간을 보장하지는 않기 때문에 실시간 처리가 필요한 경우에는 적용하기 어렵다. 이러한 문제를 해결하기 위해 RT 패치는 선점형 커널, 인터럽트 쓰레드화, 뮤텍스의 도입 등을 통해 리눅스의 실시간 처리를 지원한다. 그러나 RT 패치는 우선순위 상속만을 지원하기 때문에, 뮤텍스의 스핀락 대체로 인한 데드락 문제를 야기할 수 있다. 본 논문에서는 이를 해결하기 위하여 PCP(Priority Ceiling Protocol)의 변형인 ICPP(Immediate Ceiling Priority Protocol)을 RT 패치에 통합되도록 구현하고, 그 성능을 분석한다.

• Management Science and Financial Engineering
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• 제2권1호
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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.

• Nuclear Engineering and Technology
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• 제41권3호
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• pp.225-236
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• 2009

This study has identified human performance research issues associated with the implementation of new technology in nuclear power plants (NPPs). To identify the research issues, current industry developments and trends were evaluated in the areas of reactor technology, instrumentation and control technology, human-system integration technology, and human factors engineering (HFE) methods and tools. The issues were prioritized into four categories based on evaluations provided by 14 independent subject matter experts representing vendors, utilities, research organizations and regulators. Twenty issues were categorized into the top priority category. The study also identifies the priority of each issue and the rationale for those in the top priority category. The top priority issues were then organized into research program areas of: New Concepts of Operation using Multi-agent Teams, Human-system Interface Design, Complexity Issues in Advanced Systems, Operating Experience of New and Modernized Plants, and HFE Methods and Tools. The results can serve as input to the development of a long-term strategy and plan for addressing human performance in these areas to support the safe operation of new NPPs.