• Journal of Korea Multimedia Society
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• v.9 no.5
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• pp.658-670
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• 2006

As the educational media tends to be more digitalized and individualized, the learning paradigm is dramatically changing into e-learning. Existing on-line courseware gives a learner more chances to learn when they are home with their own PCs. However, it is of little use when they are away from their digital media. Also, it is very labor-intensive to convert the original off-line contents to on-line contents. This paper proposes education mobile contents(EMC) that can supply the learners with dynamic interactions using various multimedia information by recognizing real images of off-line contents using mobile devices. Content-based image retrieval based on object shapes is used to recognize the real image, and shapes are represented by differential chain code with estimated new starting points to obtain rotation-invariant representation, which is fitted to computational resources of mobile devices with low resolution camera. Moreover we use a dynamic time warping method to recognize the object shape, which compensates scale variations of an object. The EMC can provide learners with quick and accurate on-line contents on off-line ones using mobile devices without limitations of space.

• Proceedings of the Korea Information Processing Society Conference
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• 2014.04a
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• pp.475-478
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• 2014

최근 인터넷이 발전함에 따라 월드와이드웹(World Wide Web) 기반의 웹 서비스가 급격한 발전을 이루었다. 또한 이 웹 서비스를 바탕으로 다양한 컨텐츠들과 이를 이용하는 사용자의 수도 함께 증가하였다. 그러나 이와 같은 웹 서비스의 보편화가 증대될수록 이를 악용하려는 사이버 범죄 또한 비례하여 증가하고 있다. 최근에는 공격자들이 스마트폰을 대상으로 악성코드를 전파하기 위한 방법으로 웹 서비스를 활용하기 시작하면서 웹 서비스의 보안에 대한 중요성이 더욱 강조되고 있다. 이러한 웹 서비스 보안의 필요성을 인지하고, 많은 사람들이 무료로 쉽게 웹 서비스 보안취약점을 진단 할 수 있도록 여러 오픈소스 기반의 보안 취약점 진단도구가 연구, 개발되고 있다. 하지만 웹 서비스의 보안약점을 진단하는 도구의 적합성 평가 및 기능 분류가 명확하지 않아서 진단도구를 선택하고 활용함에 있어 어려움이 따른다. 본 논문에서는 OWASP에서 위험도에 따라 선정한 웹 서비스의 보안 취약점 Top 10 항목과 소프트웨어 보안약점 진단가이드 등을 통해 웹 서비스 보안 취약점을 진단하는 도구에 대한 분석 기준을 제시한다. 이후 오픈소스로 공개된 테스트 기반 취약점 탐지도구와 소스 기반 취약점 진단도구들에 대해 제시한 기준을 이용하여 분석한다. 본 논문의 분석결과로 웹 서비스의 안전성을 평가하기 위해 활용할 수 있는 진단 도구에 대한 분석정보를 제공함으로써 보다 안전한 웹 서비스의 개발과 운영에 기여할 것으로 기대한다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.9
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• pp.1734-1741
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• 2007

In this paper, the Hybrid SC/MRC-2/4 method in which bit synchronization and phase synchronization were not required was applied to the orthogonal MC DS-CDMA system in which each normalized subcarrier interval and processing gain had the same value, respectively, and the direct sequence spread code of each subcarrier was orthogonal. In the broadband wireless system in which multi-carrier transmission was used, a Doppler frequency shift occurred, which was caused by the difference between the highest subcarrier frequency md the lowest subcarrier frequency. In order to complement phase error caused by the shift, the orthogonal MC DS-CDMA system was analyzed so that the receiving signal could be perfectly synchronized by adjusting the PLL gain suitable for the entire system. As a result of simulations, as the PLL gain was increased, the change in the intervals was close to the case of perfect synchronization however, it became less when the PLL gain reached more than a certain value. Therefore, by selecting a proper PLL gain suitable for the system the orthogonal MC DS-CDMA can be designed in which the Hybrid SC/MRC method is applied.

• Journal of the Korea Society of Computer and Information
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• v.24 no.10
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• pp.65-70
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• 2019

In recently, ship trajectory data consisting of ship position, speed, course, and so on can be obtained from the Automatic Identification System device with which all ships should be equipped. These data are gathered more than 2GB every day at a crowed sea port and used for analysis of ship traffic statistic and patterns. In this study, we propose a method to process ship trajectory data efficiently with distributed computing resources using MapReduce algorithm. In data preprocessing phase, ship dynamic and static data are integrated into target dataset and filtered out ship trajectory that is not of interest. In mapping phase, we convert ship's position to Geohash code, and assign Geohash and ship MMSI to key and value. In reducing phase, key-value pairs are sorted according to the same key value and counted the ship traffic number in a grid cell. To evaluate the proposed method, we implemented it and compared it with IALA waterway risk assessment program(IWRAP) in their performance. The data processing performance improve 1 to 4 times that of the existing ship trajectory analysis program.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.143-146
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• 2009

The restaurants have been forced to inform the origin of ingredients to consumers due to the origin obligation policy enacted in 2008 October. However, it is difficult to trust the policy because the origin is represented by a manager's conscience. Therefore, in order to provide consumers with reliable information, we have designed, and embodied the agricultural management system using RFID and USN technology. By installing system on agricultural plantations this system not only manages environmental data such as temperature, illumination and humidity collected in real time but also offers consumers the information of fertilizers or pesticides sprayed on the crops. Before purchasing, consumers will be able to check raw flesh process and the fertilizer and agricultural chemical scattering scene of the crops as an image by using RFID tags with a leader, which more increase the reliability.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.05a
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• pp.580-583
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• 2009

It is very important to minimize the maintenance cost on easy accessibility in the production information system, change of production process line, and system expansion for globalization of logistics and production in the steel and manufacturing. In this paper, we design applying design patterns of object-oriented as well as implement web-based integrated manufacturing management system using JSP for easy accessibility of users and reduction of maintenance cost on business expansion and system integration. In addition, The proposed MES system supports various functionality such as equipment master code management, equipment management, inspection management, repair management, failure management, and statistic management in detail.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.05a
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• pp.645-648
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• 2009

According to development of Information Technology and generalization of internet, practical use field of geography information became various. Therefor various Geographic Information System (GIS) constructed to manage geography information efficiently. However, geography information data of various form is depending on graphic authorizing tool of various form being not normalized each other. So, OGC (Open Geospatial Consortium) proposed GML (Geography Markup Language) that describe normalized geography information data that can apply mutually and W3C proposed SVG (Scalable Vector Graphics) of vector base. In this paper creates GML data of XML base for geography information data processing to vector graphic object. and design and implementation of GML document editing and translation system that define code converter that create GML document through created graphic objects and change vector graphic to logic structure of XML base.

• Journal of the Society of Naval Architects of Korea
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• v.30 no.3
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• pp.75-89
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• 1993

The present paper describes an application of UA(Uncertainty Analysis) to seakeeping model test, basically according to the Performance Test Code of ASME(American Society of Mechanical Engineers), in which all the possible error sources involved in the preparation of test, calibration of instruments, data acquisition and analysis are quantified, and summed up with error propagation coefficients to the final uncertainties. The differences between the static test such as resistance and propulsion test and the dynamic test like seakeeping test are clearly identified during all the procedures of UA and asymmetric bias errors are considered. The DRE(data reduction equation) subject to present UA are the heave and pitch response amplitude operator and nondimensionalized absolute frequency. The usefulness of UA in seakeeping test were confirmed not only for quantifying errors and improving measurement accuracy but also for the validation of various seakeeping analysis tools.

• Proceedings of the Korea Information Processing Society Conference
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• 2012.11a
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• pp.72-74
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• 2012

위성의 상태를 모니터링하고 임무수행 준비 및 결과를 분석하기 위해 위성에서는 주기적으로 텔레메트리 프레임을 생성하여 지상으로 전송한다. 텔레메트리 프레임을 통해 많은 데이터가 전송될수록 정확한 위성의 상태 분석이 가능하고 위성 운용을 용이하게 할 수 있다. 그러나 위성에서 지상으로 전송할 수 있는 텔레메트리의 전송속도는 하드웨어의 성능에 따라 제한되며, 특히 저궤도 위성의 경우에는 지상과 교신이 가능한 시간이 짧다는 제약으로 인해 한정된 시간 안에 정해진 전송속도로 보낼 수 있는 데이터의 양에는 한계가 있다. 이러한 제약조건 하에서 최대한 많은 정보를 효율적으로 전송할 수 있도록 위성의 텔레메트리를 생성할 때 비트 정보들을 모아 하나의 바이트로 묶어서 텔레메트리 크기를 최소화하는 방법을 이용한다. 위성비행소프트웨어는 태스크 스케쥴링, 열제어, 전력제어, 자세제어, 원격명령처리, 원격측정데이터 처리 등의 기능별로 모듈화 되어있다. 각 모듈마다 텔레메트리로 전송되는 데이터들이 존재하고 비트 정보들을 모으는 기능도 해당하는 모듈에서 각각 담당한다. 따라서 각 모듈들이 독립적이지 못하고 텔레메트리 처리를 담당하는 모듈과 다른 모듈들 간의 커플링(coupling)이 존재하게 되어 하나의 텔레메트리 데이터 변경이 여러 모듈에 영향을 미치게 된다. 본 논문에서는 모듈들 간의 커플링을 최소화하고 텔레메트리의 변경사항이 위성비행소프트웨어 코드 자체에는 영향을 주지 않도록 하기위한 데이터베이스 테이블을 이용한 텔레메트리 처리 방안에 대하여 설명한다.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.12 no.3
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• pp.251-256
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• 2019

In this paper we proposed system and algorithm to recognize hand gestures based on the millimeter wave that is in 65GHz bandwidth. The proposed system is composed of millimeter wave radar board, analog to data conversion and data capture board and notebook to perform gesture recognition algorithms. As feature vectors in proposed algorithm. we used global and local zernike moment descriptor which are robust to distort by rotation of scaling of 2D data. As Experimental result, performance of the proposed algorithm is evaluated and compared with those of algorithms using single global or local zernike descriptor as feature vectors. In analysis of confusion matrix of algorithms, the proposed algorithm shows the better performance in comparison of precision, accuracy and sensitivity, subsequently total performance index of our method is 95.6% comparing with another two mehods in 88.4% and 84%.