• Proceedings of the KIEE Conference
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• 2001.10a
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• pp.346-348
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• 2001

In this paper a wind power simulator is designed and implemented. This simulator realize the torque of wind blade by DC motor. And squirrel-cage induction machine is used as generator and controlled to achieve the maximum power point tracking(MPPT) algorithm.

• Proceedings of the KIEE Conference
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• 2001.10a
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• pp.289-292
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• 2001

A Dual rotor turbines HAWT/VAWT combined wind turbine system that can drastically enhance the power production capability compared to conventional Single Rotor Turbine HAWT system. The combined system that takes advantage of strong point of both horizontal and vertical Axis wind turbine system developed by a venture firm : KOWINTEC of Chonbuk National University. The HAWT/VAWT hybrid system has been successfully field tested and commercial operation since Feb. 12, 2001 in Hae-chang rest park, Bu-an county near the Sae Man-Kum Sea Dike. This paper will briefly describe the field test results performance and a special aerodynamic structure with bevel-planetary gear box of Dual Rotor Wind Turbine system.

• Proceedings of the KIEE Conference
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• 1993.07a
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• pp.189-191
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• 1993

A systematic procedure for the elements of system matrix in multimachine systems with loads is suggested for the small-signal stability studies. Synchronous machines are represented by either a two-axis model or classical model. The interrelationship of submatrices of system matrix is investigated. Once elements of one submatrix are determined, they can be used to calculate the elements of the other submatrix. It is illustrated for three machine and nine bus multimachine systems with constant impedance loads, constant MVA load, constant current and power factors.

• Proceedings of the KIEE Conference
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• 2004.11b
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• pp.166-168
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• 2004

전력선 통신은 전기공급을 위해 기존에 설치되어 있는 전력선을 그대로 이용한 것으로 통신망을 새롭게 설치할 필요가 없다는 편의성 및 경제적 잇점을 가지고 있다. 최근 전력선 통신 기술은 홈오토메이션, 자동원격 검침, 원격모니터링에 적합한 기술로 주목받고 있다. 특히 전력선통신을 이용한 전력 감시시스템의 구축도 가능할 것으로 보여진다. 본 논문에서는 기존의 전력선 모뎀과 전력 측정 장비인 ACM meter를 이용하여 감시 시스템을 구성하였고, 전력선 모뎀과 ACM meter의 연계를 위하여 8051 kit를 자체 제작하여 ACM meter의 측정 데이터가 전력선 모뎀을 거쳐 컴퓨터에 모니터링 되도록 함으로써 차후 전력선 통신을 이용한 원격 감시시스템의 가능성을 연구하였다.

• Korean Journal of Materials Research
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• v.18 no.1
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• pp.26-31
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• 2008

The dc resistivity and thermoelectric power of bilayered perovskite $La_{1.4}(Sr_{0.2}Ca_{1.4})Mn_2O_7$ were measured as a function of the temperature. In the ferromagnetic phase, ${\rho}(T)$ was accurately predicted by $a_0+a_2T^2+a_{4.5}T^{4.5}$ with and without an applied field. At high temperatures, a significant difference between the activation energy deduced from the electrical resistivity and thermoelectric power, a characteristic of small polarons, was observed. All of the experimental data can be feasibly explained on the basis of the small polaron.

• Proceedings of the KIEE Conference
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• summer
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• pp.263-266
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• 2004

전력선 통신은 전기공급을 위해 기존에 설치되어 있는 전력선을 그대로 이용하는 것으로 통신망을 새롭게 설치할 필요가 없다는 편의성 및 경제적 잇점을 가지고 있다. 최근 전력선 통신 기술을 이용하여 조명제어, 침입탐지와 같은 방범, 가스원격 차단과 같은 방재, 냉난방기기의 제어와 같은 흠오토메이션, 자동원격 검침, 원격모니터링에 적합한 기술로 주목받고 있다 특히 전력선 통신을 이용한 홈네트워크의 구축도 가능할 것이다. 본 논문에서는 전력선 통신의 등장배경과 정의, 핵심기술을 알아보고, 간단한 모뎀과 사용자인터페이스를 제작하여 간단한 부하를 제어함으로써 차후 전력선 통신을 이용하여 가정내 또는 사업체에서의 부하관리의 가능성을 연구하였다.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.230-230
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• 2015

When and why do states cooperate in international basins? In recent years, there have been increasing attempts to apply international relations theories such as realism and neo-liberal institutionalism in understanding prospect of cooperation among sovereign states over shared rivers. Realists of hydropolitics argue that fate of cooperation resides in hands of hegemons and distribution of aggregate power among riparian states. Such pessimistic contention has been challenged by neo-liberal institutionalists, especially through regime theory. However, regime theory barely explains why and how cooperation emerges in the first place prior to regime formation. Therefore, the research suggests the game theory from neo-liberal institutionalism as an alternative theoretic approach. The accountability of Oye (1986)'s theoretical framework is illustrated through the case of cooperation in the Rhine River Basin.

• Journal of the Society of Naval Architects of Korea
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• v.58 no.1
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• pp.49-57
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• 2021

In the production power transmitting of a floating production system like a wind offshore floating, the power cable should be connected from the surface system into the subsea system. The connection between the surface and the subsea system will make the power cable get a dynamic load like current and wave forces. Based on this condition, a dynamic power cable is required to endure external physical force and vibration in the long-term condition. It needs more requirements than static power cable for mechanical fatigue properties to prevent failures during operations in marine environments where the external and internal loads work continuously. As a process to verify, the durability test of dynamic power cables under the marine operation environment condition was carried out by using domestic technology development.

• Journal of Korean Physical Therapy Science
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• v.13 no.1
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• pp.7-20
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• 2006

Purpose: This study was to find that what mechanism take effects that was Adjuvant Induced Arthritis in Sprague-Dawley rat and then treated the swimming and low power laser. Methods: Adjuvant Induced Arthritis was induced 24 Sprague-Dawley rat by the subcutaneous injection of a 0.2ml Freund's Complete Adjuvant into the right hind paw and right knee joint. Second injection used of 0.05ml Freund's Complete Adjuvant by same method. Arthritic rat were divided 3 groups; arthritic swimming group, arthritic laser group and case control group. The author performed several experimental tests which were the hind paw thickness, step length, knee joint space, activity of enzyme. Results: Hind paw thickness decreased in swimming and laser group. Left step length and knee joint space increased in swimming and laser. Conclusion: Swimming and low power laser therapy on the Adjuvant Induced Arthritis in rats does effective for the rheumatic arthritis therapy by decrease of hind paw thickness, increase of opposite side step length, increase of activity of albumin and IgG and increase of knee joint space.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.54 no.5
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• pp.251-258
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• 2005

Recently, the domestic and foreign power trends are the supply of high quality power and environment conservation technology based on the new energies development. So, the dispersed generation systems, such as photovoltaic, fuel cell, and battery are to be introduced in distribution systems. According to the situation change, power of high Quality and reliability are required in distribution systems with dispersed generation. Up to now, the voltage in distribution systems are regulated by ULTC of substation and pole transformer of primary feeders. These days, Step Voltage Regulator(SVR) is getting established at distribution feeders to regulate effectively voltage of primary ffeders that voltage drop exceeds $5\%$. But, because SVR is operated independently with ULTC of substation, SVR can not take play to its full effectivity. Under these circumstances, in order to deliver suitable voltages to as many customers as possible, new optimal voltage regulation algorithms are required in distribution system. So, this paper presents optimal voltage regulation algorithm to regulate voltage effectively for ULTC and SVR in distribution systems with dispersed generation systems.