• 한국산업정보학회논문지
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• 제21권1호
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• pp.7-15
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• 2016

해양의 파랑 파라미터는 해상 교통의 운행과 항해에 있어 안전성과 더불어 효율성을 위해 매우 중요하다. 본 논문에서는 X-대역의 해양 레이더를 이용하여 해류 속도, 파랑 파라미터와 같은 해상의 표현정보를 수집하는데 효율적인 알고리즘을 개발한다. 특히, 제안된 방식은 고정된 제어 방식을 사용하는 것 대신에 반복적인 보정 과정을 채택함으로써, 최적화된 해류 속도를 효과적으로 계산할 뿐만 아니라, 최적화된 방식으로 비용함수를 도입하도록 설계된다. 실험을 통해서 제안한 알고리즘은 기존의 알고리즘에 비해서 파랑 정보를 추출하는데 매우 효과적임을 보인다.

• 한국표면공학회지
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• 제30권5호
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• pp.333-346
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• 1997

Plasma spray processes for functional coatings of tubular SOFC ( Soild oxide Fuel Cell).consisting of air electrode, oxide electrolyte, an fuel electrode, are optimized by fully saturated fractional factorial testing. Material and electric characteristics of each coating are analtsed by the implementation of SEM and optical microscope for evaluating microstructure and porosity, X-ray diffraction method for investigating compositional change between raw powder and sprayed coating, and Van der Pauw method for measuring electrical conductivity. LSM ($La_{0.65}Sr_{0.35}MnO_3$air electrode and Ni-YSL fuel electrode coatings have porosities of around 23~30% sufficient for effective fuel and oxidant gas supply to electrochemical reaction interfaces and electrical conductivities of around 90 S/cm and 1000 S/cm, respectively, enough for acting as current collecting electrodes. YSZ($ZrO_2-8mol%Y_2O_3$) electrolyte film has a high ionic conductivities of 0.05~0.07 S/cm at $1000^{\circ}C$ in air atmosphere, but appears to be somewhat too porous to reduce the thickness. for enhancing the cell efficiency. A unit tubular SOFC has beem fabricated by the optimized plasma spray processes for each functional coating and the cell. Its electrochemical chracteristics are investigated by measuring voltage-current and power density with variation of operationg temperature, radio of fuel to air gas flowrates, and total gas flowrate of reactants.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2007년도 동계학술발표대회 논문집
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• pp.564-569
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• 2007

This study describes thermal performance of solar cooling and hot water for demonstration system with ETSC(Evacuated tubular solar collector) installed at Seo-gu art center of Kwangju. For demonstration study, a reading room with about 350㎡ was heated and cooled with the solar system. The system was consisted of ETSCs, storage tank, hot water supply tank, subsidiary boiler, subsidiary tank, absorption chiller, chiller storage tank, and cooling tower. The results of the experimental study indicated that the total solar energy gain as daily performance on a sunny day (August 25, 2007) with total daily radiation of $606\;W/m^2$ was 671 kWh, the collecting efficiency of 55%. In the case of supplies to heat source more than $83^{\circ}C$, cooling time operated by solar was driven 8.8 hours, cooling energy generated by solar system was 179 kWh and the solar cooling fraction was 79.2%, and hot water supplied with surplus heat source by the solar system was 201 kWh.

• 한국태양에너지학회 논문집
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• 제37권5호
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• pp.39-47
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• 2017

In a hot water system using solar energy, solar heat is not simply collected by the heat collecting plate, but by heat exchange between the solar collector (flat or vacuum type) and the hot water storage tank. Therefore, the amount of collected solar energy depends on the hot water usage patterns that determine the temperature of the thermal storage tank. Also, if the temperature of the hot water stored in the storage tank exceeds the dangerous temperature during the summer, the heat must be released for safety. If the temperature of the hot water in the storage tank is low, it is necessary to heat by the auxiliary heat source. In this study, three buildings are defined as hotel, swimming pool, and school facilities. And we calculated the released heat energy, auxiliary heat source, and pure storage heat energy based on different hot water usage patterns and installation angle of the solar collectors.

• 한국정보통신학회논문지
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• 제14권2호
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• pp.312-320
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• 2010

현재 운영 중인 대부분의 온라인 모니터링 시스템은 유선망과 근거리 무선망 중심으로 데이터 프로토콜 변환 동기화, 측정 장치의 유연한 운용 요구, 유지보수 등 관리 비용의 증가를 발생시킨다. 따라서 이런 문제점을 해결하기 위해 본 논문에서는 유무선 통신망과 효과적으로 연동 운용 가능한 CDMA 통신망 기반의 환정정보 모니터링 시스템 구축방안과 특히, 복수개의 자료수집 장치에 대해 효과적인 운용이 가능한 SMS 데이터 송수신 프로토콜을 제안한다. 그리고 제안된 프로토콜의 운용성과 안전성을 입증하고 SMS를 이용한 데이터 전송 및 운용 효율성을 분석한다.

• 한국정보통신학회논문지
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• 제18권3호
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• pp.576-585
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• 2014

대량의 개인정보가 수집되어 활용됨에 따라 개인정보 유출 등의 보안 문제가 발생하고 있다. 이에 최근에는 수집된 개인정보를 암호화 하여 저장하고 활용하는 방법이 사용되고 있다. 본 논문에서는 기존에 수집된 대량의 개인정보를 단시간에 암호화하기 위한 방법으로 맵리듀스 기반의 분산 암호화 처리 방법을 제안하고, 시스템을 설계하고 구현하였다. 또한 맵리듀스 기반의 분산 암호화 처리 방법의 성능을 검증을 위해 테스트 환경을 구축하여 비교 실험을 진행하였다. 실험 결과 토큰 서버의 암호화 처리 시간이 순차처리 대비 평균 시간 효율이 약 15.3% 정도 향상 하였으며, 병렬처리대비 약 3.13%정도 향상되는 것을 확인 하였다.

• Journal of Information Processing Systems
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• 제13권4호
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• pp.1014-1028
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• 2017

Social networking services (SNSs) such as Twitter, MySpace, and Facebook have become progressively significant with its billions of users. Still, alongside this increase is an increase in security threats such as cross-site scripting (XSS) threat. Recently, a few approaches have been proposed to detect an XSS attack on SNSs. Due to the certain recent features of SNSs webpages such as JavaScript and AJAX, however, the existing approaches are not efficient in combating XSS attack on SNSs. In this paper, we propose a machine learning-based approach to detecting XSS attack on SNSs. In our approach, the detection of XSS attack is performed based on three features: URLs, webpage, and SNSs. A dataset is prepared by collecting 1,000 SNSs webpages and extracting the features from these webpages. Ten different machine learning classifiers are used on a prepared dataset to classify webpages into two categories: XSS or non-XSS. To validate the efficiency of the proposed approach, we evaluated and compared it with other existing approaches. The evaluation results show that our approach attains better performance in the SNS environment, recording the highest accuracy of 0.972 and lowest false positive rate of 0.87.

• 한국정보통신학회논문지
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• 제19권7호
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• pp.1705-1710
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• 2015

근래에 ICT 기술을 농업에 적용시켜 효율성과 생산성을 제고시키는 기술인 스마트농업에 대한 연구개발이 활발히 이루어지고 있다. 그러나 아직 국제적으로 공인된 국제 표준이 구축되지 않아 외산 장비 도입과 해외 진출시 많은 어려움이 있는 상황이다. 이러한 필요에 의해 국제 표준화가 ITU-T SG13에서 국내 전문가들에 의해 추진되고 있다. 본 논문에서는 서비스 적용례를 기술할 수 있는 시나리오를 기반으로 하여 스마트농업 서비스들을 제안하며, 제안된 서비스 구성을 반영시킨 문서는 ITU-T Y.2238 권고안으로 승인되었다.

• 한국도로학회논문집
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• 제15권5호
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• pp.177-185
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• 2013

PURPOSES : This study attempts to design and establish the road surface condition detection system by using the image processing that is expected to help implement the low-cost and high-efficiency road information detection system by examining technology trends in the field of road surface condition information detection and related case studies. METHODS : Adapted visual information collecting method(setting a stereo camera outside of the vehicle) and visual information algorithm(transform a Wavelet Transform, using the K-means clustering) Experiments and Analysis on Real-road, just as four states(Dry, Wet, Snow, Ice). RESULTS : Test results showed that detection rate of 95% or more was found under the wet road surface, and the detection rate of 85% or more in snowy road surface. However, the low detection rate of 30% was found under the icy road surface. CONCLUSIONS : As a method to improve the detection rate of the mobile road surface condition information detection system developed in this study, more accurate phase analysis in the image processing process was needed. If periodic synchronization through automatic settings of the camera according to weather or ambient light was not made at the time of image acquisition, a significant change in the values of polarization coefficients occurs.

• 한국유기농업학회지
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• 제19권spc호
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• pp.230-233
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• 2011

We collected and examined germplasm resources of lettuces, edible chrysanthemums and mallows for organic farmers. We found that 3 genotypes (OL-51, OL-52, and OL-63) are suitable for organic cultivation. The main use of treatment for grey mold among eco-friendly pest control methods is helpful to increase efficiency of seed-gathering after collecting and evaluating a total of 64 kinds of lettuces-collected 43 South Korea local varieties, 8 kinds cultivated by the Highland Agriculture Research Center, 4 kinds of cultivated lettuces, and 9 kinds for sales- to choose appropriate kinds of lettuces for organic cultivation in South Korea. We chose those with more than 300 leaves (OC-18, OC-44, and OC-51) after evaluation of yield characteristics of a total of 62 edible chrysanthemums. We covered each genotype of seed of edible chrysanthemums when gathering the seeds by ourselves so as not to decrease the purity of each genotype. We chosed OM-38, OM-39, and OM-40 for their yield performance and germination rates among the total 41 genotypes of mallows. We selected 9 genotypes of lettuces, editable chrysanthemums and mallows with possibility of organic cultivation and found that they can be used permanently through self seed-gathering on organic farms.