• 한국건설관리학회논문집
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• 제16권4호
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• pp.21-29
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• 2015

우리나라의 건설공사비지수는 지난 2004년부터 매월 발행되고 있다. 이 지수는 공사비 실적자료의 갱신과 공사비 변동분석, 시장가격의 평가에 직간접적으로 활용되어 왔다. 그런데 이 지수는 한국은행의 산업연관표와 생산자물가지수를 이용하는 가공통계자료이기 때문에, 이들 기초통계 자료에 변화가 있을 경우, 지수 작성모델의 변경이 반드시 필요하다. 최근 한국은행은 생산자물가 지수와 산업연관표의 작성원칙과 기준연도를 변경하였다. 이에 본 연구에서는 최근 변경된 기초통계자료의 내용과 그 영향을 분석하고, 이를 토대로 건설공사비지수를 새롭게 개선하였다. 또한 기존의 생산자물가지수 등과 그 편제 품목 및 가중치 변화 등을 분석함으로써 개선된 지수의 타당성을 검증하였다.

• Journal of electromagnetic engineering and science
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• 제4권4호
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• pp.168-174
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• 2004

A bandwidth-enhanced and phase noise-improved differential LC-tank VCO is proposed in this paper. By connecting the varactors to the bases of the cross-coupled transistors of the proposed LC-tank VCO, its input negative resistance has been widened. Also, the feedback capacitor Cc in the cross-coupling path of the proposed LC-tank VCO attenuates the output common-mode level modulated by the low-frequency noise because the modulated common-mode level jitters the varactor bias point and degrades phase noise. Compared with the fabricated conventional LC-tank VCO, the proposed LC-tank VCO demonstrates $200\;\%$ enhancement in tuning range, and 6 - dB improvement in phase noise at 6 MHz offset frequency from 5.4-GHz carrier. We achieved the phase noise of - 106 dBc/Hz at 6 MHz offset, and $10\;\%$ tuning range from the proposed LC-tank VCO. The proposed LC-tank VCO consumes 12 mA at 2.5 V supply voltage.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 F
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• pp.1973-1976
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• 1998

Recently, new trend in telecommunication device is to apply low voltage, about 3.3V-1.5V. However, it is undesirable in view of high efficiency and power desity which is the most important requirement in the distributed power system. Rectification loss in the output stage, in on-board converter for distributed power system are constrained to obtain high efficience at low output voltage power suppies. This paper explains the basic operational principles of three kinds of ZVS DC/DC converters with self-driven synchronous rectifier. The three topologies are analyzed by simulation and exprimentation, and the characteristics comparisons of high efficience converter are carried out in view of the minimized rectification losses in the out stage.

• 한국콘텐츠학회논문지
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• 제16권5호
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• pp.157-171
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• 2016

본 연구의 목적은 기초연구분야에서 정부연구비의 변동과 연구성과간의 관계를 파악하는데 있다. 이를 위해, 개인연구사업 중 대학에서 수행된 IT 분야의 기초연구과제들을 대상으로 분석을 실시하였다. 여러 과제 특성 변수를 활용하여, 종속변수와 독립변수와의 관계를 통제하였다. 회귀분석결과를 살펴보면, 정부 연구비 증감은 모든 연구성과(가중논문 수, 특허 수)와 통계적으로 유의미한 정(+)의 관계에 있는 것으로 분석되었다. 또한, 연구성과에 가장 큰 영향을 미치는 과제는 연구비가 증액된 과제로, 연구비가 유지된 과제에 비해 최대 8배 정도의 큰 영향력을 보였다. 연구비가 감액된 과제는 연구비가 유지된 과제에 비해 최대 4배 정도의 큰 영향력을 갖은 것으로 확인하였다. 이러한 연구결과를 기반으로 학술적 측면, 실무적 측면의 시사점을 제시하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 합동 추계학술대회 논문집 정보 및 제어부문
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• pp.407-410
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• 2002

As a part of electro-mechanical totally implantable artificial heart, a transcutaneous energy transmission system has been developed. By mutual magnetic induction between the first coil on the skin and the subcutaneously implanted second coil, the system transfers electrical power through the skin. This research aimed a minimizing the size of the implanted part as well as maximizing the transfer efficiency. When an air gap is 1$\sim$2cm, voltage gain and current gain low and it is hard to transfer energy due to large leakage flux. That is, the required input voltage and input current must be large compared with the output voltage and output current, respectively, This paper research the inverter topology and the control method in order to increase the voltage gain and the current gain. For this purpose, this inverter employs double tune to compensate the large leakage inductance of primary and secondary of the transcutaneous transformer. And the output energy of transcutaneous energy transmission system supply for Lithium-ion battery charger.

• Journal of Power Electronics
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• 제7권3호
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• pp.265-270
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• 2007

Equal rating DC-DC converter modules can be connected in series at the input for circuits requiring higher input voltages and in parallel at the output for circuits requiring higher output currents. Since the converter modules may not be practically identical, closed loop control has to ensure that each module equally shares the total input voltage and the load current. A control scheme consisting of a common output voltage loop, individual inner current loops and individual input voltage loops have been designed in this work to achieve input voltage and load current sharing as well as load voltage regulation under supply and load disturbances. The output voltage loop provides the basic reference for the inner current loops, which are also modified by the respective input voltage loops. The average of the converter input voltages, which is dynamically varying, is chosen as the reference for input voltage loops. This choice of reference eliminates interaction among different control loops. Type II compensators and Fuzzy Logic Controllers (FLCs) are designed and compared through MATLAB based simulation and FLC is found to be satisfactory. Hence TMS320F2407A DSP based FLC is implemented and the results are presented which prove the superiority of the FLC developed for this research.

• 한국자동차공학회논문집
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• 제23권3호
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• pp.271-278
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• 2015

This paper develops an OBD Diagnostic Program (Program) using Visual Studio (C#), which was used to diagnosis malfunction information from OBD-II system vehicles. We accomplished this using the Program, Diagnostic tests, Board (STN1110), FTDI Basic Cable, Mini USB Cable, OBD Data Cable, and both hybrid and regular vehicles. The Program tests real-time data output, DTC output, sensor value output, engine RPM, waveform data, OBD type check, PID inspection, and whole monitoring. We found vehicles used in this research had 19 PIDs, which was within OBD-II regulations. We also gathered data on control and diagnostic code regulated by OBD-II system, such as, sensor output value, engine RPM, DTC output, each PID analytic value, OBD type, fuel mode, and whole monitoring result value. Using the data collected through the Program appropriately can lead to more effective diagnostic practices and contribute to education.

• ETRI Journal
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• 제27권5호
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• pp.473-483
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• 2005

In this paper, we propose two LC voltage-controlled oscillators (VCOs) that improve both phase noise and tuning range. With both 1/f induced low-frequency noise and low-frequency thermal noise around DC or around harmonics suppressed significantly by the employment of a current-current negative feedback (CCNF) loop, the phase noise in the CCNF LC VCO has been improved by about 10 dB at 6 MHz offset compared to the conventional LC VCO. The phase noise of the CCNF VCO was measured as -112 dBc/Hz at 6 MHz offset from 5.5 GHz carrier frequency. Also, we present a bandwidth-enhanced LC VCO whose tuning range has been increased about 250 % by connecting the varactor to the bases of the cross-coupled pair. The phase noise of the bandwidth-enhanced LC-tank VCO has been improved by about 6 dB at 6 MHz offset compared to the conventional LC VCO. The phase noise reduction has been achieved because the DC-decoupling capacitor Cc prevents the output common-mode level from modulating the varactor bias point, and the signal power increases in the LC-tank resonator. The bandwidth-enhanced LC VCO represents a 12 % bandwidth and phase noise of -108 dBc/Hz at 6 MHz offset.

• Asian Pacific Journal of Cancer Prevention
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• 제16권11호
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• pp.4733-4739
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• 2015

Background: Oral cancer is the most common cancer among men and second only to breast cancer among women in Pakistan. For the effective control and prevention of oral cancer, Pakistan needs to recognize the importance of research and generation of the evidence-base which can inform policy making and planning and implementation of intervention programs. The objective of this review was to quantify oral cancer research output in Pakistan. Materials and Methods: A systematic electronic search in "Medline", "ISI-Web of Science" and "Pakmedinet", supplemented by a Google search, was carried out in January and February, 2014, to identify literature from Pakistan relevant to oral cancer. The selection of publications for the review was carried out according to preset criteria. Data were recorded and analyzed using Microsoft Excel. Results: A total of 166 publications comprising 62 case series, 36 cross sectional, 31 case control, 10 basic laboratory research, eleven reviews and two trials, were included in this review. Some 35 % of the publications focused on risk factors for oral cancer. COMSATS Institute of Information Technology was the institution with the highest contribution. Conclusions: There is a lack of research in the field of oral cancer research in Pakistan. Focused efforts should be put in place to improve both quality and quantity of oral cancer research in the country.

• 수산경영론집
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• 제43권3호
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• pp.75-87
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• 2012

Today, the Korean fisheries is undergoing significant hardships, both domestically and internationally. While declining amount of catch, ascending international oil prices and others pose a compelling challenge to the fishing sector, the ever strengthening influence of international institutions related to fisheries and international trade organizations also compel to bring about myriad of changes in the realm of fishery products. Against the backdrop, this study attempted to examine the fisheries catch, aquaculture, service, processing fields in terms of its rippling effect and of how the industry has been changed by analyzing the past and present through an input-output analysis. As for research methods, 168 items of the input-output tables in 2000, 2005, 2009, and 2010 were integrated to form and classify 32 sectors (28 basic sectors + catch, aquaculture, fishery service, processed fishery products) so as to generate production inducement coefficient, sensitivity coefficient, and impact coefficient. The analysis results revealed that : though the linkage effect of fishery industry was not very sizable, the impact coefficient of the processed fishery products was high; the consumption and investment coefficient sector among production inducement coefficient was on an upturn trend ; the export coefficient was tended to decline. In the future research, it is necessary to carry out a study based on the integration of detailed classification (404 sector) and a study and analysis of fishery industry by different regions through the inter-regional input-output tables. The fishery industry is one of the crucial industries in Korea. The fishery industry is not only important in its own right but also significant as it exerts influence over other industries. Therefore, it is required that there should be more investment and supports for the development of the fishery industry, and pay efforts to ensure that the investment and development could lead to mutual growth for both the fishery and other various industries.