• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 A
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• pp.341-343
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• 2000

Traditionally electric power system are operated in such a way that the total fuel cost is minimized regardless of accounting for tie-lines transmission constraint and emissions produced. But tie-lines transmission and emissions constraint are very important issues in the operation and planning of electric power system. This paper presents the Two-Phase Neural Network(TPNN) to solve the Economic Load Dispatch (ELD) problem with tie-lines transmission and emissions constraint considering transmission losses. The transmission losses are obtained from the B-coefficient which approximate the system losses as s quadratic function of the real power generation. By applying the proposed algorithm to the test system, the usefulness of this algorithm is verified.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 D
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• pp.1067-1070
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• 1997

This paper presents an algorithm that evaluates load supplying capability(LSC) considering voltage constraint in composite power systems. To evaluate the LSC considering the voltage constraint, we apply tangent vector approach using an enhanced power flow method based on continuation algorithm. The validity and effectiveness of the proposed method is confirmed through the simulation of a model system.

• Nuclear Engineering and Technology
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• 제53권6호
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• pp.1924-1930
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• 2021

By using miniature SENB specimens, the fracture properties of the materials in the region of welded metal, 321 stainless steel heat affected zone, 690 alloy heat affected zone of 321/690 dissimilar metal girth welded joints were tested. Both the J-resistance curves and critical fracture toughness of the three different materials are affected by the crack size because of the effect of crack tip constraint. Groups of constraint corrected J-resistance curves of the three materials are obtained according to J-Q-M approach. The welded metals exhibit the best fracture resistance but the worst fracture resistance is observed in the material of 690 alloy heat affected zone.

• KIEE International Transactions on Power Engineering
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• 제5A권3호
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• pp.221-227
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• 2005

This paper evaluates minimum and maximum power exchange considering economic and technical characteristics between Russia and ROK. First, we evaluate minimum power exchange to assure the economic feasibility by comparison with the total cost and benefit of the interconnected line. For evaluating maximum exchange power, system constraints are considered, which are examined through load flow and dynamic analysis by using the PSS/E program. As a result of these evaluations, we suggest the reasonable range of power exchange between ROK and Russia considering economic and technical constraints with the interconnection scenario that power system interconnection between ROK and Russia will be realized in the year 2010.

• 대한간호학회지
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• 제36권2호
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• pp.403-414
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• 2006

Purpose: The purpose of this study was to investigate the effects of constraint-induced (CI) movement using self-efficacy on U/E function of chronic hemiplegic patients. CI movement discourages the use of the unaffected U/E, combined with intensive training of the affected U/E. Method: A non-equivalent pretest-posttest design was used. Study subjects were 40 hemiplegic patients conveniently selected from 2 different community health centers. The experimental subjects participated in the CI movement program for 6 hours daily over a period of two weeks. The exercises for affected U/E consisted of warming up, main exercise and ADL practice. To encourage the participants' behaviors self-efficacy enhancing strategies were used, which included performance accomplishment, vicarious experience, verbal persuasion and emotional arousal. Result: After 2 weeks of treatment, the grip power, pinch power, wrist flexion/extension, elbow flexion, and shoulder flexion/extension were significantly higher in the experimental subjects than in the control subjects. However, there was no significant difference in hand functions of the two groups. Conclusion: The above results show that the constraint-induced movement using self-efficacy could be an effective nursing intervention for improving U/E function of chronic hemiplegic patients. Long term studies are needed to determine the lasting effects of constraint-induced movement.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권6호
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• pp.2873-2892
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• 2019

Reducing the interference to the licensed mobile users and obtaining the energy efficiency are key issues in cognitive heterogeneous networks. A corresponding rate loss constraint is proposed to be used for the sensing-based spectrum sharing (SBSS) model in cognitive heterogeneous networks in this paper. Resource allocation optimization strategy is designed for the maximum energy efficiency under the proposed interference constraint together with average transmission power constraint. An efficiency algorithm is studied to maximize energy efficiency due to the nonconvex optimal problem. Furthermore, the relationship between the proposed protection criterion and the conventional interference constraint strategy under imperfect sensing condition for the SBSS model is also investigated, and we found that the conventional interference threshold can be regarded as the upper bound of the maximum rate loss that the primary user could tolerate. Simulation results have shown the effectiveness of the proposed protection criterion overcome the conventional interference power constraint.

• Nuclear Engineering and Technology
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• 제16권4호
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• pp.181-194
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• 1984

변분법을 사용하여 원자로의 핵연료 관리문제를 연구하였다. 원자력 발전소에 영향을 미치는 두 함수 즉 이윤함수와 가격함수는 원자로의 연소도방정식과 최대허용출력 밀도에 대한 부등 제약조건이며, 이들은 임계성의 제약조건이 된다. 초기이윤의 변분해는 원자로에 뚜렷한 두 영역이 있음을 보여 주었다. 즉 일정 출력 영역과 최소 재고량 또는 평활 중성자속 영역이 그것이다. 이들 든 영역의 변이점은 전력에 대한 이윤과 연료에 대한 이자 지급에 상당히 중요하다. 그러므로 각 영역에서 동일 농축도의 핵연료를 가질 동일 부피의 세 영역으로 된 원자로를 최적화 하기 위하여 핵연료 주기 가격 함수가 사용 되었다. 최대 허용 출력 밀도에 대한 부등 제약조건들은 이들 부등 제약 조건이 원자로심의 어느 특정 점이나 로심주기를 통하여 항상 동일 제약조건이 되어야 한다. 원자로의 임계성과 출력밀도에 대한 동일 제약조건에 관계된 핵연료의 연소도에 대한 계차 방정식의 해를 구하였으며 최적 농축도의 위치를 구하기-위하여 구배법을 사용하였다. 이들 계산결과는 부동 제약 조건들을 적절히 적용하면 원자로를 최적화하기 위하여 비선형 최적 기술이 사용될 수 있음을 보여 주었다.

• 대한기계학회논문집A
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• 제22권3호
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• pp.504-518
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• 1998

Degree-Of-Freedom(DOF) for most power transmission system varies according to the operation status which consists of friction elements to change the power flow or to adjust the speed ratio such as clutches, brakes or one-way clutches. To simulate the dynamic characteristics of automatic power transmission system which is a typical example of such a variable DOF systems, many sets of governing equations and complicated phase decision routines are necessary. In this paper dynamic constraint theorem is derived explaining the torque transmission characteristics during the clutch engagement process and a robust stable algorithm is developed describing this phase transition phenomenon effectively by introducing the concept of direct torque and virtual damping. Finally, applying this algorithm to a passenger car automatic transmission gear consisting of several friction elements, an efficient simulation methods for such a complex system will be suggested that is very simple and systematic.

• 한국컴퓨터정보학회논문지
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• 제11권3호
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• pp.161-166
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• 2006

본 논문은 시간 제약 조건하에서의 모듈 선택 재사용을 이용한 CPLD 저전력 기술 매핑을 제안한다. 일반적인 상위 수준 합성에서의 스케줄링은 실제적인 라이브러리의 복잡한 재사용을 허용하지 않는다. 반면 제안한 알고리즘은 주어진 사용자 정의 모듈을 실제적인 RT 라이브러리 모듈 재사용과 공유된 자원에서의 스위치 활동의 자원 공유하여 스케줄링을 수행한다. 스케줄링은 체이닝과 멀티사이클링을 이용해 다양한 상위 레벨 벤치마크의 환경에서 최적의 스케줄링의 결과를 얻는다. 스케쥴링의 결과 재사용된 자원은 CPLD 저전력 기술 매핑 알고리즘을 이용하여 저전력으로 회로를 구현한다.

• 한국정보통신학회논문지
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• 제13권9호
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• pp.1851-1857
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• 2009

본 논문은 소모 전력 계산을 위해 회로를 구현하고자 FPGA 기술 매핑을 위한 소모 전력을 고려한 재사용 모듈 생성 알고리즘을 제안한다. 제안한 알고리즘은 FPGA 기술 매핑을 위해 사용되는 재사용 모듈에 대해 소모 전력을 고려하여 RT 라이브러리를 생성하는 알고리즘이다. 소모 전력 계산을 위해 회로를 구현하고자 하는 FPGA를 선정한다. 선정된 FPGA를 구성하고 있는 LUT의 조건을 고려하여 전체 소모 전력이 최소가 되도록 기술 매핑을 수행한다. 이러한 정보를 이용하여 할당된 결과의 모듈들 중에서 주어진 소모 전력에 맞는 모듈을 선정하여 회로를 구현한다.