• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.3-5
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• 2008

This paper presents a hybrid winding connection method for torque characteristics improving of a traction SRM. In order to get a high torque in wide speed range and torque ripple reduction, series and parallel winding connection are changed according to operating speed. From the analysis of torque character operation mode and efficiency, the proposed control scheme is verified.

• 대한수학회보
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• 제50권3호
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• pp.705-717
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• 2013

In this paper, we study the geometry of half lightlike submanifolds M of a semi-Riemannian manifold $\tilde{M}$ with a semi-symmetric non-metric connection subject to the conditions; (1) the characteristic vector field of $\tilde{M}$ is tangent to M, the screen distribution on M is totally umbilical in M and the co-screen distribution on M is conformal Killing, or (2) the screen distribution is integrable and the local lightlike second fundamental form of M is parallel.

• Steel and Composite Structures
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• 제2권4호
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• pp.277-296
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• 2002

A research investigation of single bolt lap-plate connection load-deformation behavior is presented. Each important characteristic of this behavior is evaluated and two methods for analytically approximating the behavior are developed and presented. The first of these methods is a component method in which the behavior of the connection is modeled as a combination of the behavior of the parts. The second method utilizes a number of parametric relationships that relate the connection parameters to coefficients of two non-linear continuous analytical curves. The test results from four independent experimental programs that investigated the behavior of single bolt lap-plate connections are used in the development and verification of these methods.

• 한국품질경영학회:학술대회논문집
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• 한국품질경영학회 2010년도 춘계학술대회
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• pp.283-290
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• 2010

This paper suggest that the derivation of good and practical ideas is important for the successful use of Kano model. Wish List, Bug List and Forced Connection Method as well as Brainstorming were applied to PMP(Portable Multimedia Player) in order to derive customer attributes. Wish List and Bug List are variants of Brainstorming, which are contrary to each other. Forced Connection Method is designed to bring about bisociation which is a typical characteristic of creative thinking.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2003년도 추계학술대회 논문집
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• pp.81-84
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• 2003

For increasing power of photovoltaic systems, serial and parallel connection needed. In parallel connection, a desirable characteristic of parallel-connected supply system is that individual converters share the load current equally and stably. The current sharing(CS) can be implemented using two approaches. The first one, known as a Droop method, and the other is Active current-sharing. In Droop method, current distribution characteristics relies on the high output impedance of each converter. This scheme is more simple and no need interconnections. but also has a disadvantages of degrading current sharing characteristics. In this paper, using droop method at multiful-parallel connection with it's convenience and simplicity.

• 한국전기전자재료학회논문지
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• 제20권12호
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• pp.1077-1081
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• 2007

Thermal expanded core (TEC) fiber can reduce, being advantaged from thermal diffusion technology, connection loss by expanding the tolerance in relation to axial offset and gap when making optical connection having mode field diameter (MFD) of optical fiber expanded locally. In this paper, TEC fiber fabrication system based on the frame brushing techniques using twin-torch tip was designed and developed in order to maintain a stable thermal diffusion and single-mode when manufacturing TEC fiber. We were able to obtain that varied kinds of TEC fibers of which MFD could have been extended between $20\;{\mu}m$ and $40\;{\mu}m$ by TEC fiber fabrication system. In addition, the characteristic of connection loss was measured by alignment two TEC fibers of which MFD was $30\;{\mu}m$.

• 전기학회논문지P
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• 제57권4호
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• pp.383-387
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• 2008

This paper analyzes the operation characteristics of a self excited induction generator with Steinmetz connection. For this analysis, the symmetrical components analysis is used to obtain the related expressions and the excitation capacitance and the magnetizing reactance are determined in turn by the condition of self excitation which includes the input impedance of the generator as viewed across load terminals. Two simultaneous equations of the condition of self excitation itself are solved by using the real and imaginary function in an application software. This method is applied to simulate the operation characteristics when the generator is driven at rated speed and the specified excitation capacitor is connected across the lagging phase. The results show that better operation characteristics except generated frequency are obtained by using relatively large excitation capacitance and resistive load.

• International Journal of Naval Architecture and Ocean Engineering
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• 제11권1호
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• pp.244-255
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• 2019

Interest in renewable energy has been increasing in recent years for many reasons, and there have been many studies on new types of wave energy converters and mechanisms for them. However, in this paper, motion characteristics of a wave energy converter with a wave activating body type is studied with an experiment. In order to conduct the experiment, a simple wave activating body type's wave energy converter is proposed. Experimental variations consist of connection type and location. The connection type controls the rotation motions of structures, and the connection location controls the distance between structures. The movement of floating structures, such as rotation, velocity, and acceleration, is measured with a potentiometer and a motion capture camera. Using the recorded data, the motion characteristics derived from the experimental variations are investigated.

• 전기학회논문지P
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• 제57권3호
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• pp.236-243
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• 2008

This paper analyses magnetic flux saturation of matching transformer considering characteristic of dynamic voltage restorer(DVR) system to solve voltage sags which are considered the dominant disturbances affecting power quality. This DVR consist of PWM inverter to inject arbitrary voltage, LC low pass filter and matching transformer for isolation and grid connection. However, the matching transformer has an excess of inrush current by magnetic flux saturation in the core of transformer. Due to this inrush current, the rating of matching transformers is double for needed nominal rating for protection of DVR. Therefore, in this paper, an advanced modeling method of magnetic flux saturation is used to analyze a magnitude and characteristic of magnetizing current. Simulation and experimental results considering characteristic of DVR system are provided to demonstrate the validity of the proposed analysis method.

• 전기학회논문지
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• 제64권4호
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• pp.598-604
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• 2015

A Chebyshev filter is well known for having a sharp skirt characteristic and equi-ripple. On the other hand, a Butterworth filter has a smooth skirt characteristic and maximally flat ripple. This paper analyzes the skirt characteristics of the filters with the cascade connection. The paper deals with the Chebyshev BPF, Cascading Chebyshev BPF, Butterworth BPF, Cascading Butterworth*Chebyshev BPF. First of all, the paper designs the prototype analog LPF in order to analyze skirt characteristics of the BPFs. Then the paper does the frequency transformation into the BPFs and tests the BPFs with cascading them. As a result, the skirt characteristics of the Chebyshev BPF was the sharpest and those of the Cascading Chebyshev BPF, Butterworth BPF, Cascading Butterworth*Chebyshev BPF was superior in order. The validity of the paper was confirmed through minute measurements of test results.