• 상하수도학회지
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• 제26권6호
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• pp.915-925
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• 2012

On-off control performance of target pumping station was experimented by changing measurement methods for storage level or inflow and operating logic for control system setting. Four scenarios with different measurement methods and operational logic were examined in the Matlab/Simulink environment. Controller's on-off control repetition that was frequent before has been reduced and more effective and stable system operation was found to be possible with the scenarios. Moreover, defensive operation enforced prevention of floods by changing measurement methods enabled economic operation that made an utmost use of storage volumes.

• 한국추진공학회지
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• 제25권1호
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• pp.68-76
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• 2021

본 연구에서 대상으로 삼은 직렬 하이브리드 시스템은 무인기용으로 왕복엔진, 발전기, 배터리를 주 동력원으로 사용한다. 발전기는 왕복엔진의 구동축에 직결되며, 왕복엔진-발전기 세트의 운용 특성은 지상통합시험을 통해 확인하였다. 본 연구에서는 해당 시험 결과를 바탕으로 왕복엔진-발전기 출력과 배터리 출력을 효율적으로 사용하기 위한 제어로직을 제시하였고, 로직에 따른 왕복엔진-발전기와 배터리의 출력 변동은 시뮬레이션을 통해 확인하였다. 그 결과, 발전기 출력은 제시된 제어로직에 의해 배터리 출력과 함께 추진요구전력을 공급함을 확인하였다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 추계학술대회 논문집
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• pp.1562-1569
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• 2008

In this paper, the study on development of an applicable logic on the characteristics of Rolling stocks will be proposed. In general, this logic which means decision logic or LTA(Logic Tree Analysis) is used to analyze how the failure mode have an effects on the system. The effect would be categorized as safety, operational, economical, etc. To do this, based on the typical logics which have been applied to other industries, such as plants, aero, etc. This paper emphasizes two crucial parameters that is one cost the other customer service, that have an important role in railway system operation. In conclusion, as mentioned above as the logic for which could be effectively applied for the railway system(RST) would be developed.

• 한국과학교육학회지
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• 제9권1호
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• pp.19-37
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• 1989

The purpose of this study was to investigate the development of logical thinking and scientific reasoning pattern of Korean high school students. To carry out this study subjects were selected about 2,000 Junior high school students, and about 4,100 senior high school students throughout the nation. They were identified as concrete, transitional or formal operational stage with the use of TOLT(the Test of Logical Thinking) by Tobin and Capie(1980), and TOSR(the Test of Scientific Reasoning) by W.A Farmer(1986). This study turned out that more than 76% of Junior high school students were classified as the concrete operational stage and about 44% of senior high school students were classified as the formal operational stage, while about 26% of them were still in the concrete operational level. This study showed that the main factor of the intellectual development of students is learning by the gradual advancement of their grades and especially entrance into the senior high school rather than by the physical growth. This study also showed that there are the take-off stage of the development of logical thinking between fourteen and fifteen years of their ages. Less than 25% of junior high school students were in the formal operational stages which are capable of control of variables, probabilistic, correlation and combinational logic in problem-solving situation, while 33-54% of senior high school students were in the formal operational levels. 38% of junior high school students were in the formal operational stage which is capable of proportional logic, while about 55% of senior high school students were in the formal operational stage. Less than 20% of senior high school students were classified as group of highly capable of scientific reasoning, while more than 23% of them were classified as group of poor capability. It also turned out that there are differences or no differences between male and female students of each school in problem-solving situation regarding each logic approach. These differences were proved to be fluctuating depending on the situations and their grades. The other results of this study is similar to those of other researches such as Tomlinson-Keasey 1972, Coleman 1973, Lawson 1973, Lawson and Renner 1974, Neimark 1975, Han 1982, and Kim 1989.

• 한국신뢰성학회지:신뢰성응용연구
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• 제3권1호
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• pp.73-82
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• 2003

Reliability Centered Maintenance(RCM) was initially developed for the commercial aviation industry in the late 1960s and now is equally applicable to a variety of equipment other than aircraft. RCM is a method for establishing a preventive maintenance program which will efficiently and effectively allow the achivement of the the required safety and availability levels of equipment and structures. RCM provides for the use of a decision logic tree to identify applicable and effective preventive maintenance requirements for equipment and structures according to the safety, maintenance requirements for equipment and structures according to the safety, operational and economic consequences of identifiable failures, and the degradation mechanism, reponsible for the those failures. The end result of working through the decision logic is a judgement as to the necessity of performing a maintenance task. In this paper, we provide guiding principles based on IEC 60300-3-11 for RCM analysis methods and operational method of structure and equipment.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1996년도 춘계학술발표회논문집(1)
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• pp.349-354
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• 1996

SACOM(Simulation Analyser with Cognitive Operator Model) is being developed at Korea Atomic Energy Research Institute to simulate human operator's cognitive characteristics during the emergency situations of nuclear power plans. An operator model with error mechanisms has been developed and combined into SACOM to simulate human operator's cognitive information process based on the Rasmussen's decision ladder model. The operational logic for five different cognitive activities (Agents), operator's attentional control (Controller), short-term memory (Blackboard), and long-term memory (Knowledge Base) have been developed and implemented on blackboard architecture. A trial simulation with a scenario for emergency operation has been performed to verify the operational logic. It was found that the operator model with error mechanisms is suitable for the simulation of operator's cognitive behavior in emergency situation.

• International Journal of Computer Science & Network Security
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• 제23권12호
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• pp.13-26
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• 2023

Recently, the development of wireless network technologies has been advancing in several directions: increasing data transmission speed, enhancing user mobility, expanding the range of services offered, improving the utilization of the radio frequency spectrum, and enhancing the intelligence of network and subscriber equipment. In this research, a series of contradictions has emerged in the field of wireless network technologies, with the most acute being the contradiction between the growing demand for wireless communication services (on operational frequencies) and natural limitations of frequency resources, in addition to the contradiction between the expansions of the spectrum of services offered by wireless networks, increased quality requirements, and the use of traditional (outdated) management technologies. One effective method for resolving these contradictions is the application of artificial intelligence elements in wireless telecommunication systems. Thus, the development of technologies for building intelligent (cognitive) radio and cognitive wireless networks is a technological imperative of our time. The functions of artificial intelligence in prospective wireless systems and networks can be implemented in various ways. One of the modern approaches to implementing artificial intelligence functions in cognitive wireless network systems is the application of fuzzy logic and fuzzy processors. In this regard, the work focused on exploring the application of fuzzy logic in prospective cognitive wireless systems is considered relevant.

• Nuclear Engineering and Technology
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• 제52권7호
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• pp.1471-1480
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• 2020

This research presents a case study on the remediation of a radioactive waste (uranium: U) utilizing a multi-objective fuzzy optimization in an electrocoagulation process for the iron-stainless steel and aluminum-stainless steel anode/cathode systems. The incorporation of the cumulative uncertainty of result, operational cost and energy consumption are essential key elements in determining the feasibility of the developed model equations in satisfying specific maximum contaminant level (MCL) required by stringent environmental regulations worldwide. Pareto-optimal solutions showed that the iron system (0 ㎍/L U: 492 USD/g-U) outperformed the aluminum system (96 ㎍/L U: 747 USD/g-U) in terms of the retained uranium concentration and energy consumption. Thus, the iron system was further carried out in a multi-objective analysis due to its feasibility in satisfying various uranium standard regulatory limits. Based on the 30 ㎍/L MCL, the decision-making process via fuzzy logic showed an overall satisfaction of 6.1% at a treatment time and current density of 101.6 min and 59.9 mA/㎠, respectively. The fuzzy optimal solution reveals the following: uranium concentration - 5 ㎍/L, cumulative uncertainty - 25 ㎍/L, energy consumption - 461.7 kWh/g-U and operational cost based on electricity cost in the United States - 60.0 USD/g-U, South Korea - 55.4 USD/g-U and Finland - 78.5 USD/g-U.

• 한국항공우주학회지
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• 제41권10호
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• pp.805-812
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• 2013

스마트무인기의 비행제어컴퓨터는 탑재장비와의 입/출력 신호처리, 비행제어법칙 연산 그리고 고장진단 및 이중화 기능 등이 구현된 비행운용프로그램이 탑재되어 있다. 비행운용프로그램은 PowerPC 755 프로세서와 VxWorks 5.5 실시간운영체제 환경에서 개발되었다. 비행운용프로그램은 메모리 참조 모듈, 탑재장비 입/출력 신호처리 모듈 그리고 비행제어법칙 모듈로 구성되었고 각각의 모듈은 계층 구조로 설계되었다. 메모리 참조 모듈과 신호처리 모듈은 벤치 테스트를 통해 검증되었고, 비행제어법칙 모듈은 시뮬레이션 시험, 지상통합시험, 안전줄 시험 그리고 비행시험을 통해 검증되었다. 본 논문에서는 비행운용프로그램의 개발환경, 소프트웨어 구조 그리고 검증 및 관리방법에 대해서 기술하였다.

• 대한전자공학회논문지
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• 제23권1호
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• pp.42-45
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• 1986

This paper introduces novel functionally integrated logic elements which are conceptuallized for large scale integrated circuits. Efforts are made to minimize the gate size as well as to reduce the operational voltage, without sacrificing the speed performance of the gates. The process used was a rather conventional collector diffusion isolation(CDI) process. New gate structures are formed by merging several transistors of a gate in the silicon substrate. Thested elements are CML(Current Mode Logic) and EECL (Emitter-to-Emitter Coupled Logic)gates. The obtained experimental results are power-delay product of 6~11pJ and delay time/gate of 1.6~1.8 ns, confirming the possibility of these novel gate structures as a VLSI-candidate.