• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2002년도 하계학술대회 및 세미나
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• pp.220-230
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• 2002

고속으로 주행하는 차량으로부터 차량의 일시정지함이 없이 자동으로 통행요금을 징수하기 위한 ETC(Electronic Toll Collection, 통행요금자동징수)서비스는 전용의 무선통신방식, 전자지불수단, 암호화, 영상인식, 실시간제어등의 다양한 기술을 필요로 한다. KT ETC 시스템은 능동형 DSRC(Dedicated Short Range Communication, 단거리전용통신)를 이용한 상용의 ETC 시스템이다. 본 논문에서는 KT ETC 시스템의 개발과 관련하여 핵심 기술인 능동형 DSRC와 ETC 서비스를 위한 스마트카드 기술등을 소개하고, KT ETC 시스템에 고유한 ETC 서비스 처리절차를 소개한다.

• Journal of electromagnetic engineering and science
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• 제12권1호
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• pp.20-25
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• 2012

In this paper, the EM wave absorber for ETC system was designed and fabricated. We fabricated several samples in different composition ratios of flaked sendust and CPE(Chlorinated Polyethylene). Absorption abilities were simulated in accordance with different thicknesses of the prepared absorbers and changed complex relative permittivity and permeability according to composition ratio. The optimized mixing ratio of flaked sendust and CPE was found as 60 : 40 wt.% by experiments and simulation. Then the EM wave absorber was fabricated and tested using the simulated data. As a result, the developed EM wave absorber has the thickness of 2.75 mm and absorption ability was 22.5 dB in the case of normal incidence at 5.8 GHz. Therefore, it was confirmed that the newly developed absorber can be used for ETC system.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 추계학술대회 논문집
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• pp.1272-1277
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• 2004

GPS type portable-alarm-system is composed of satellite receiving equipment, signal transmission equipment, etc. Time errors occur because of the processing methods of the satellite receiving equipment and signal generator, the positional error of GPS itself, etc. With the recent rise of train speed, it becomes very important to secure the stability of portable-alarm-system from time errors, The present study estimated errors caused by the structure of portable-alarm-system, GPS errors. etc., and verified them. In addition, it examined the effects of such errors on portable-alarm-system according to train speed.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1989년도 하계종합학술대회 논문집
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• pp.251-253
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• 1989

The Battery Storage System (BSS) has been used in foreign country for Load Levelling, Flicker Compensation, Load Frequency Control, etc. because it has easy application characteristics compared to the other storage system such as the Pumped Hydro System, Compressed Air System, etc.. In this paper, the application field and available capacity of BSS is outlined in Korea.

• 한국전자거래학회:학술대회논문집
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• 한국전자거래학회 2001년도 International Conference CALS/EC KOREA
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• pp.165-176
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• 2001

* Extension of EC(Electronic Commerce) * Standard of Message -EDI : UN/EDIFACT, ANSI X12, etc -XML : ebXML, CML, MathML, WIDL, etc * Various of Information -Business Transaction Data -Private Data : ID, Password, Personal Information -Charge Data : Accounts, Card, etc * Message Level Security(omitted)

• 한국자동차공학회논문집
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• 제18권2호
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• pp.122-128
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• 2010

To meet the NOx limit without a penalty of fuel consumption, urea-SCR system is currently regarded as promising NOx reduction technology for diesel engines. SCR system has to achieve maximal NOx conversion in combination with minimal $NH_3$ slip. In this study, the performance characteristics of urea-SCR system with open loop control were assessed in the European Transient Cycle(ETC) for heavy duty diesel engine. The SCR inlet temperaure varied in the range of 200 to $340^{\circ}C$ in the ETC cycle. Open loop control calculated the urea flow rate based on the NOx and NSR map which gave for each combination of SCR inlet temperature and space velocity the normalized $NH_3$ to NOx stoichiometric ratio which resulted in a steady-state $NH_3$ slip of 20ppm. During the ETC cycle, the open loop control with the optimized NSR offset achieved NOx reduction of 80% while keeping the average $NH_3$ slip below 10ppm and maximum 20ppm. It was also found that NOx sensor was cross-sensitive to $NH_3$ and a control strategy for cross-sensitivity compensation was required in order to use a NOx sensor as feedback device.

• Journal of Preventive Medicine and Public Health
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• 제23권3호
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• pp.345-357
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• 1990

Accumulated data on medical care utilization among the insured in Korea Medical Insurance Corporation can explain the health status of the population. The purpose of this study was to analyze a change of the disease-mix and utilization pattern by controlling the size of the population enrollment. Major findings of the study are as follows : 1. The changes of inpatient disease-mix a. Utilization rate was 139.2% in 1988 against 1980. b. Disease groups higher than the average utilization rate included neoplasms, endocrine, nutritional and metabolic diseases and immunity disorders, mental disorders etc. Meanwhile, disease groups seen less often were infections and parasistic diseases, diseases of blood and bloodforming, diseases of the digestive system etc. c. Utilization rate was up 106.3% in 1988 compared to 1985, and diseases above that average level were ill-defined intestinal infections, chronic liver disease and cirrhosis, diabetes mellitus, essential hypertension, etc. d. The disease-mix by institution in 1988 compared to 1985 shows that chronic disorders rank high in general hospitals whereas opthalmologic, obstetric, and orthopedic diseases rank high in private clinics. 2. The changes of outpatient disease-mix a. Utilization rate was up 175.2% in 1988 compared to 1980. b. Disease groups higher than the average utilization rate included neoplasms, endocrine, nutritional and metabolic diseases and immunity disorders, mental disorders etc. And disease groups seen less often were infections and parasistic diseases, diseases of the respiratory system, diseases of the genitourinary system. etc. c. Utilization rate was up 104.0% in 1988 compared to 1985, and diseases above that average level were gastric ulcer, diseases of hard tissues of teeth, etc. And diseases seen below that average level were acute nasopharyngitis(common cold). acute upper respiratory infections of multiple or unspecified sites, etc. It was concluded that medical care utilization level was increased, and that, from 1980 to 1988, disease-mix shifted to the chronic disorders. Chronic disorders accounted for more medical care utilization in general hospitals.

• 한국전자파학회논문지
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• 제11권7호
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• pp.1147-1155
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• 2000

ITS의 다양한 서비스를 위한 5.8GHz 주파수 대역에서의 무선 통신 시스템의 설치는 상호간의 간섭을 발생시키며, 그 대표적인 경우로서 이종 통신 시스템인 DSRC 시스템과 ECT 시스템의 주파수 공유는 상호간의 간섭으로 인하여 양쪽 또는 한쪽 시스템이 통신 오류나 통신 방해를 받게 된다. 이에 대한 해결책으로 차단벽(Shield Plate), 안테나 지향성(Antenna Directionality), 전력 제어(Power Control)의 이용 등이 제안되고 있으나, 이것은 원하는 사용자와 간섭원의 위치에 대한 정보를 RSU에서 가지고 있지 않으므로, 완전한 해결책이 괼 수 없다. 그러므로, 본 논문에서는 원하는 사용자에 대해서는 상대적으로 높은 이득을 취하고, 간섭원의 방향으로는 null을 형성하는 적응 배열 안테나를 DSRC, ECT 시스템의 상,하향 링크에 적용함으로써, 두 시스템에 미치는 간섭의 영향이 약 20dB 감쇄된 것을 BER 성능을 통해 보인다.

• 한국통신학회논문지
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• 제31권6B호
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• pp.527-533
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• 2006

본 논문은 앞으로 산업의 많은 부분에 영향을 미치게 될 ITS(Intelligent Transport System)의 주요 통신 수단인 단거리 전용 통신(DSRC : Dedicated Short Range Communication) 시스템의 성능을 매체 접근 제어(MAC : Media Access Control)단에서의 전송 효율을 분석함으로써 평가하였다. 현재 DSRC는 자동요금징수(ETC : Electric Toll Control)과 버스정보시스템(BIS : Bus Information System) 등의 전송 효율이 시스템이 미치는 영향이 극히 낮은 시스템에 사용되고 있으나, 향후 첨단 운전자 정보 안내 시스템(ADIS : Advanced Driver Information Systems) 또는 첨단차량 및 도로 시스템(AVHS : Advanced Vehicle Highway System) 등과 같은 고도화된 시스템으로 진화할 경우 DSRC의 주요한 매체인 적외선(IR : Infra Red) 방식과 주파수(RF : Radio Frequency) 방식의 MAC 프레임 속성에 따른 서비스의 질은 급격히 변화될 것이다. 따라서 본 논문에서는 그 특성을 전송 속도에 따른 시간의 함수로 구성하여 분석함으로써 이후 다양한 ITS 서비스에 활용할 수 있는 지표를 제공하고자 하였다.

• 한국항해항만학회지
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• 제35권9호
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• pp.749-753
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• 2011

A leisure ship has a stand-alone type power system, and a generator is in use on this condition. But the generator cannot be operated in condition of leisure activity, ocean measurement and etc, because of environment and noise. Recently, renewable energy system is connected with power system of the leisure-ship for saving energy. The renewable energy system can not supply the stable power to leisure-ship because power generation changes according to weather condition. And most of the leisure ship is operated without methodical power management system. This study's purpose is to develop SPMS(Smart Power Management System) algorithm using the renewable energy (photovoltaic, wind power and etc.). The proposed algorithm is able to supply stable the power according to operation mode. Furthermore, the SPMS manages electric load (sailing and communication equipment, TV, fan, etc.) and reduces operating times of the generator. In this paper, the proposed algorithm is realized and executed by using LabVIEW. As a result, the hour for operating the generator is minimized.