• 디지털산업정보학회논문지
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• 제5권2호
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• pp.87-93
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• 2009

In this paper, we propose and evaluate the availability of single sensor node using a hierarchial modeling approach. We divides a sensor node into a software and hardware and analyze failures of each component. We construct Markov chains to represent the components of a sensor node, and then we construct a hierarchical model which use fault tree in upper level and Markov chains in lower level. We evaluate the availability and down of single sensor node.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.16-18
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• 2008

Several methods are proposed in the literature for losses segregation of single phase induction motor. Generally we could divide two methods for experimental determination of losses segregation for single phase induction motor. The one is relatively complicated method based on Parameter estimation of single phase induction motor. The other is simple method based on IEEE Standard 114. Segregation of losses in single phase induction motor is more complicated than that in three phase induction motor, because of the backward magnetic field component in the motor and multiplicity of different single phase type. In this paper, therefore, we studied losses segregation of capacitor-run single phase induction motor.

• 한국소음진동공학회논문집
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• 제24권11호
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• pp.890-897
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• 2014

This work investigated the electromechanical performance of a cantilevered vibration energy harvester incorporating the single crystal PMN-PZT, manufactured with the most recent technology of solid-state single crystal growth. The performances of single crystal PMN-PZTs with two different crystallographic axes such as [011] and [001] are compared with those of PZT ceramics. From the investigations, it is shown that the [001]-poled PMN-PZT is advantageous for the excitations containing single dominant frequency component, while the single crystal [011]-$d_{32}$ is superior in terms of the energy storage density and energy conversion efficiency.

• 한국전자거래학회지
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• 제9권2호
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• pp.145-161
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• 2004

컴포넌트 기반 개발(Component Based Development, CBD)은 미리 구현된 블록단위의 컴포넌트를 사용하여 소프트웨어 개발 비용 및 시간을 단축할 수 있다. 또한 컴포넌트는 내부의 상세 부분을 숨기고 인터페이스를 제공하여 대형 어플리케이션을 개발하는데 복잡성을 감소시킬 수 있다. 엔터프라이즈 프레임 워크 환경에서의 패밀리 (Family)의 공통적인 요구사항은 컴포넌트 내 업무 워크플로우 형태로 표현될 수 있으나, 다양한 패밀리 멤버(Family Member)의 요구사항에 특화된 워크플로우를 하나의 컴포넌트 내에 표현하는 것은 매우 어렵다. 따라서 패밀리 멤버 (Family Member)를 위한 컴포넌트간 워크플로우 가변성 관리 및 구헌 방법에 대한 필요성은 끊임없이 요구되어 왔다. 본 논문에서는 .NET 기반 하에 엔터프라이즈 프레임워크에서 컴포넌트 워크플로우 가변성을 위한 구현 기법을 제시한다. 제시된 컴포넌트 워크플로우 가변성 구현 기법은 엔터프라이즈 프레 임워크에서 패밀리가 사용할 수 있는 공통 업무 워크플로우가 컴포넌트 내에 이미 생성되었음을 가정하며. 다양한 패밀리 멤버에 특화된 컴포넌트간의 워크플로우 구성 및 실행을 위한 기법으로 컴포넌트간 워크플로우의 확장성을 높여주게 된다.

• 정보처리학회논문지D
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• 제12D권7호
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• pp.1023-1030
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• 2005

컴포넌트 기반 개발(Component Based Development, CBD)은 미리 구현된 블록단위의 컴포넌트를 사용하여 소프트웨어 개발비용 및 시간을 단축할 수 있다. 또한 컴포넌트는 내부의 상세 부분을 숨기고 인터페이스를 제공하여 대형 어플리케이션을 개발하는데 복잡성을 감소시킬수 있다. 엔터프라이즈 프레임워크 환경에서의 패밀리(Family)의 공통적인 요구사항은 컴포넌트 내 업무 워크플로우 형태로 표현될 수 있으나 ,다양한 패밀리 멤버(Family Member)의 요구사항에 특화된 워크플로우를 하나의 컴포넌트 내에 표현하는 것은 쉽지 않다. 따라서 패밀리 멤버(Family Member)를 위한 컴포넌트간 워크플로우 가변성 관리 및 구현 방법에 대한 필요성은 끊임없이 요구되고 있다. 본 연구에서는 은행업무의 엔터프라이즈 프레임워크에서 컴포넌트 워크플로우 가변성을 위한 구현 기법을 적용한 사례로 제시하였다. 예시된 컴포넌트 워크플로우 가변성 구현 기법은 엔터프라이즈 프레임워크에서 패밀리가 사용할 수 있는 공통 업무 워크플로우가 컴포넌트 내에 이미 생성되었음을 가정하며, 다양한 패밀리 멤버에 특화된 컴포넌트간의 워크플로우 구성 및 실행을 위한 기법으로 컴포넌트간 워크플로우의 확장성을 높여주게 된다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 B
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• pp.1260-1263
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• 2000

Vector control of a single phase induction machine(SPIM) is usually employed by mechanical methods than electrical ones. The disadvantage of a SPIM has large noise at the starting. Using auxiliary winding which is only utilized for starting, the SPIM can be controlled with the vector control method. Regarding a auxiliary winding one phase, the SPIM is analyzed by the unsymmetrical two phase motor and phase transformation is unnecessary such as three phase IM. Including a auxiliary winding, SPIM is modeled by mathematical getting by component of turns ratio with main to auxiliary winding. It will be take with complicated resultant formula, by comparison to symmetrical three phase TM. For using the vector control theory, it must be decoupled of rotor flux and torque component. stator current is controlled and decoupled. This paper presents a variable-speed control system of SPIM, which to decoupled with flux and torque component and to use machine equivalent circuit referred to rotor, conventionally three phase IM by similar method.

• 전력전자학회논문지
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• 제22권3호
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• pp.185-192
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• 2017

This paper proposes a single-stage interleaved soft-switching electrolytic capacitor-less EV charger with reduced component count and simple circuit structure. The proposed charger achieves ZVS turn-on of all switches and ZCS turn-off of all diodes without regard to voltage and load variation. It achieves high power density even without an input filter due to CCM operation and bulky electrolytic capacitors and without a low-frequency component in the transformer. A 2 kW prototype of the proposed charger with sinusoidal charging is built and tested to verify the validity of the proposed operation.

• Journal of Power Electronics
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• 제17권1호
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• pp.222-231
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• 2017

In this paper, a new architecture for a cost-effective power conditioning systems (PCS) using a single-sourced asymmetric cascaded H-bridge multilevel inverter (MLI) for photovoltaic (PV) applications is proposed. The asymmetric MLI topology has a reduced number of parts compared to the symmetrical type for the same number of voltage level. However, the modulation index threshold related to the drop in the number of levels of the inverter output is higher than that of the symmetrical MLI. This problem results in a modulation index limitation which is relatively higher than that of the symmetrical MLI. Hence, an extra voltage pre-regulator becomes a necessary component in the PCS under a wide operating bias variation. In addition to pre-stage voltage regulation for the constant MLI dc-links, another auxiliary pre-regulator should provide isolation and voltage balance among the multiple H-bridge cells in the asymmetrical MLI as well as the symmetrical ones. The proposed PCS uses a single-ended DC-DC converter topology with a coupled inductor and charge-pump circuit to satisfy all of the aforementioned requirements. Since the proposed integrated-type voltage pre-regulator circuit uses only a single MOSFET switch and a single magnetic component, the size and cost of the PCS is an optimal trade-off. In addition, the voltage balance between the separate H-bridge cells is automatically maintained by the number of turns in the coupled inductor transformer regardless of the duty cycle, which eliminates the need for an extra voltage regulator for the auxiliary H-bridge in MLIs. The voltage balance is also maintained under the discontinuous conduction mode (DCM). Thus, the PCS is also operational during light load conditions. The proposed architecture can apply the module-integrated converter (MIC) concept to perform distributed MPPT. The proposed architecture is analyzed and verified for a 7-level asymmetric MLI, using simulation results and a hardware implementation.

• 한국세라믹학회지
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• 제13권2호
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• pp.8-16
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• 1976

The conductive transparent film is prepared by spraying thin salt solution. In stannic chloride solution as a base solution, various dopants such as Al, Co, Cu and Ni were dissolved respectively as a chloride state and then the films were made by spraying solutions on hot glass plates. The properties of them were compared with those of the stannic salt single component film. The films doped with copper oxide and nickle oxide were improved by decreasing their sheet resistivity and temperature coefficient of resistivity. In comparison with the sheet resistivity and temperature coefficient of resistivity of stannic oxide single component film, being 2.5 K ohm/$\textrm{cm}^2$ and -1650ppm/$^{\circ}C$ respectively, its values of the film containing 15 mol % of copper oxide and formed at 40$0^{\circ}C$ were 2.5K ohm/$\textrm{cm}^2$ and -920ppm/$^{\circ}C$ respectively. The film containing 15 mol % of nickel oxide and formed at 50$0^{\circ}C$ has shown its sheet resistivity and temperature coefficient 0.7 K ohm/$\textrm{cm}^2$ and -940ppm/$^{\circ}C$ respectively.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1999년도 봄 학술발표회 논문집
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• pp.151-158
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• 1999

The single layer latticed domes have various behaviors with each geometrical shape and scale, and they are affected by vertical component as well as horizontal component of the dynamic load. And they represent very different earthquake responses under each ground acceleration compared with another structural systems. Generally, all of the members of latticed domes undergo three dimensional deflections if they are subjected to arbitrary one dimensional horizontal load under earthquake motions. And their response characteristics are very different to their shapes, rise/span ratios, and damping mechanisms. In this study the .earthquake response behavior is verified according to the factor of each shape, rise/span ratio, ana damping ratio of latticed domes, which undergo horizontal and vertical earthquake motions by numerical approaches.