• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 추계학술대회 논문집
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• pp.146-146
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• 2009

최근에 광도전체와 형광체를 기반으로 평판형 디지털 방사선 검출기의 상업적 발전가능성에 많은 관심을 가지고 있다. 본 연구는 기존의 직접변환방식에 널리 사용되었던 비정질 셀레늄 (amorphous selenium) 기반의 디지털 방사선 검출기보다 높은 전기적신호 및 동작특성을 가지는 물질층을 제작하기 위해 High Purity (99.99%)의 상용화된 $PbI_2$를 특수용매에 담가두었다가 약 1시간동안 Biology 초음파 처리한 후 농축기를 사용하여 건조된 $PbI_2$를 3Roll-milling을 사용하여 미세크기의 Powder를 얻어내었다. 합성된 $PbI_2$ Powder를 PIB(Particle-in-Binder)법을 이용하여 전도성을 가진 ITO(Indium-tin-oxide)코팅된 유리판에 제작된 필름의 상부에 Magnetron sputtering system 을 사용하여 전극을 $1cm{\times}1cm$의 크기로 증착하였다. I-V 테스트를 통하여 X선 조사시 $PbI_2$필름의 Sensitivity, Dark current, SNR(signal-to-noise ratio)을 측정하여 필름의 전기적 검출 특성을 정량적으로 평가하였고 SEM(scanning electron microscope)을 통하여 입자의 크기를 관찰하였다.

• 한국지능시스템학회논문지
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• 제11권7호
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• pp.569-573
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• 2001

An approximate representation of discrete functions {f$_{i,j}\mid$｜i, j=-1, 0, 1, …, N+1}in two variables by a fuzzy system is described. We use the cubic B-splines as fuzzy sets for the input fuzzification and spike functions as the output fuzzy sets. The ordinal number of f$_{i,j}$ in the sorted list is taken to be the out put fuzzy set number in the (i, j) th entry of the fuzzy rule table. We show that the fuzzy system is an exact representation of the cubic spline function s(x, y)=$\sum_{N+1}^{{i,j}=-1}f_{i,j}B_i(x)B_j(y)$ and that the approximation error S(x, y)-f(x, y) is surprisingly O($h^2$) when f(x, y) is three times continuously differentiable. We prove that when f(x, y) is a gray scale image, then the fuzzy system is a smoothed representation of the image and the original image can be recovered exactly from its fuzzy system representation when it is a digitized image.e.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 추계학술대회 논문집
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• pp.250-254
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• 2007

As photovoltaic(PV) power generation systems become more common, it will be necessary to investigate islanding detection method for PV systems. Islanding of PV systems can cause a variety of problems and must be prevented. However, if the real and reactive powers of the load and PV system are closely matched, islanding detection by passive methods becomes difficult. Also, most active methods lose effectiveness when there are several PV systems feeding the same island. The active frequency drift positive feedback method(AFDPF) enables islanding detection by forcing the frequency of the voltage in the island to drift up or down. In this paper the research for the minimum value of chopping fraction gain applied digital phase-locked-loop (DPLL) to AFDPF considering output power quality and islanding prevention performance are performed by simulation and experiment according to IEEE Std 929-2000 islanding test.

• 한국측량학회지
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• 제16권2호
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• pp.291-297
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• 1998

일반적으로 수치지도제작을 수행하기 위해서는 종이에 인쇄된 원도를 컴퓨터상에서 작업할 수 있는 수치자료로 변환하는 자료입력과정과 작업이 끝난 자료를 출력하는 도면출력과정에 입출력장비가 이용된다. 본 연구에서는 수치지도 작업과정에 수반되는 입력장비중 벡터형태의 자료를 직접적으로 생성할 수 있는 장점에 의해 부분 도화된 수정도화 원도의 입력시 주로 이용되는 디지타이저와, 작업의 용이성 에 의해 주로 원도의 입력과정에 이용되는 스캐너에 대해 작업방법 및 입출력장비 특성에 따른 위치오차를 분석하였으며, 출력장비에 따른 위치오차분석에서는 플로터방식과 출력도면의 재질에 따른 위치정확도를 분석하였다.

• Korean Journal of Acupuncture
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• 제21권3호
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• pp.137-146
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• 2004

Objective : The purpose of this study is to report the patient with peripheral neuropathy, who improved by Oriental medical treatment. Methods : The patient was managed by acupuncture, moxibustion, physical treatment and herbal medicine. We checked digital infrared thermographic imaging(D.I.T.I.), electromyography(E.M.G.), nerve conduction velocity(N.C.V.), deep tendon reflex(D.T.R.), sensory recover area and range of motion(R.O.M.) of knee & ankle. Results : After 6 week treatment, clinical sign(the movement and sense of leg) of improvement was appeared. Also E.M.G., N.C.V., D.T.R. and D.I.T.I. was recovered to nearly normal range. Conclusion : The results suggest that combination of acupunture, moxibustion and herbal medicine is good method for treatment of peripheral neuropathy. But further studies may be required to concretely prove the effectiveness of this methods for treating peripheral neuropathy.

• Journal of Power Electronics
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• 제14권3호
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• pp.444-457
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• 2014

This paper presents the design and realization of a digital PV simulator with a Push-Pull Forward (PPF) circuit based on the principle of modular hardware and configurable software. A PPF circuit is chosen as the main circuit to restrain the magnetic biasing of the core for a DC-DC converter and to reduce the spike of the turn-off voltage across every switch. Control and I/O interface based on a personal computer (PC) and multifunction data acquisition card, can conveniently achieve the data acquisition and configuration of the control algorithm and interface due to the abundant software resources of computers. In addition, the control program developed in Matlab/Simulink can conveniently construct and adjust both the models and parameters. It can also run in real-time under the external mode of Simulink by loading the modules of the Real-Time Windows Target. The mathematic models of the Push-Pull Forward circuit and the digital PV simulator are established in this paper by the state-space averaging method. The pole-zero cancellation technique is employed and then its controller parameters are systematically designed based on the performance analysis of the root loci of the closed current loop with $k_i$ and $R_L$ as variables. A fuzzy PI controller based on the Takagi-Sugeno fuzzy model is applied to regulate the controller parameters self-adaptively according to the change of $R_L$ and the operating point of the PV simulator to match the controller parameters with $R_L$. The stationary and dynamic performances of the PV simulator are tested by experiments, and the experimental results show that the PV simulator has the merits of a wide effective working range, high steady-state accuracy and good dynamic performances.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년 학술대회 논문집 정보 및 제어부문
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• pp.388-390
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• 2006

This paper presents a hybrid SoC design for phase detection of single tone signal. The designed hybrid SoC is composed of three functional blocks, i.e., an analog to digital converter module, a phase detection module and a controller module. A design of the controller module is based on a 16-bit RISC architecture. An I/O interface and an LCD control interface for transmission and display of phase measurement values are included in the design of the controller module. A design of the phase detector is based on a recursive sliding-DFT. The recursive architecture effectively reduces the gate numbers required in the implementation of the module. The ADC module includes a single-bit second-order sigma-delta modulator and a digital decimation filter. The decimation filter is designed to give 98dB of SNR for the ADC. The effective resolution of the ADC is enhanced to 98dB of SNR by the incorporation of a pre FIR filter, a 2-stage cascaded integrator- comb(CIC) filter and a 30-tab FIR filter in the decimation. The hybrid SoC is verified in FPGA and implemented in 0.35 CMOS Technology.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.140.4-140
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• 2001

This paper presents the duplex controller operated as master slave for Self Excited Static Type excitation system and the results of operation for duplex digital excitation system. Software is made up duplex multi-tasking control algorithm which is based on VxWorks(real-time OS), preprocessing algorithm for input-output signal, BSP & Device Driver for interfacing hardware and software, and OIS(Operator Interface Station) program, HMI S/W. Master controller and slave controller intercommunicate dominant data to minimize bump when controller switchover from master to slave occurs. Communication between master controller and slave controller is duplicated and communication between OIS and controller is duplicated. Hardware is made up VMEBUS based controller which is designed with PPC & I/O board ...

• 대한전자공학회논문지
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• 제18권5호
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• pp.30-34
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• 1981

본 논문은 디지탈 시스템의 회로측정 평가방식에 관한 연구로서, 조합논리회로와 순서논리회로에서의 회로복잡도와 부분회로에 대한 외부 단자로부터의 접근도를 구하고, 이 수로부터 측정평가방식을 논하였다. 따라서 회로설계 초에 이 평가방식을 적용해 봄으로써, 더 좋은 측정평가도를 얻도록 재설계되어져야 하며 이러한 설계방법은 시스템 유지보수에 매우 경제적이고 신뢰도를 높일 수 있다. 또한 스테픈슨-그레손의 방법과 본 방법의 회로측정 평가도를 비교하면 결과 값은 서로일치하면서 본 방법이 계산과정에서 매우 간편하였다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1992년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 19-21 Oct. 1992
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• pp.75-80
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• 1992

This paper deals with the design scheme of the custom control circuit for optimizing the interface of peripheral devices to general-purpose controllers for the high speed digital system. When the various peripheral devices such as memory, I/O devices and buffers which operate at low speed are interfaced to the microprocessor which operates at high speed, inserting the proper wait state to the processor is required. The proposed scheme designed with random logic may be applied to the high performance graphic system like the X-terminal. This circuit provides the flexibility and system independancy for the optimum digital system design.