• Journal of KIISE:Software and Applications
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• v.31 no.5
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• pp.586-594
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• 2004

Because web documents become creation and disappearance rapidly, users require the recommend system that offers users to browse the web document conveniently and correctly. One largely untapped source of knowledge about large data collections is contained in the cumulative experiences of individuals finding useful information in the collection. Recommendation systems attempt to extract such useful information by capturing and mining one or more measures of the usefulness of the data. The existing Information Filtering system has the shortcoming that it must have user's profile. And Collaborative Filtering system has the shortcoming that users have to rate each web document first and in high-quantity, low-quality environments, users may cover only a tiny percentage of documents available. And dynamic recommendation system using the user browsing pattern also provides users with unrelated web documents. This paper classifies these web documents using the similarity between the web documents under the web document type and extracts the user browsing sequential pattern DB using the users' session information based on the web server log file. When user approaches the web document, the proposed Dynamic recommendation system recommends Top N-associated web documents set that has high similarity between current web document and other web documents and recommends set that has sequential specificity using the extracted informations and users' session information.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.16 no.2
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• pp.165-172
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• 2018

As an approach for estimation of the droplet size in the molten salt-liquid metal extraction process, a droplet formation experiment at room temperature was conducted to evaluate the applicability of the Scheele-Meister model with water-mercury system as a surrogate that is similar to the molten salt-liquid metal system. In the experiment, droplets were formed through the nozzle and the droplet size was measured using a digital camera and image analysis software. As nozzles, commercially available needles with inner diameters (ID) of 0.018 cm and 0.025 cm and self-fabricated nozzles with 3-holes (ID: 0.0135 cm), 4-holes (ID: 0.0135 cm), and 2-holes (ID: 0.0148 cm) were used. The mercury penetration lengths in the nozzles were 1.3 cm for the needles and 0.5 cm for the self-fabricated nozzles. The droplets formed from each nozzle maintained stable spherical shape up to 20 cm below the nozzle. The droplet size measurements were within a 10% error range when compared to the Scheele-Meister model estimates. The experimental results show that the Scheele-Meister model for droplet size estimation can be applied to nozzles that stably form droplets in a water-mercury system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.5
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• pp.1-9
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• 2016

Railroad bridges account for 25% of the entire high-speed rail network. Railway bridges are subject to gradual structural degradation or fatigue accumulation due to consistent and repeating excitation by fast moving trains. Wireless sensing technology has opened up a new avenue for bridge health monitoring owing to its low-cost, high fidelity, and multiple sensing capability. On the other hand, measuring the transient response during train passage is quite challenging that the current wireless sensor system cannot be applied due to the intrinsic time delay of the sensor network. Therefore, this paper presents a framework for monitoring such transient responses with wireless sensing systems using 1) real-time excessive vibration monitoring through ultra-low-power MEMS accelerometers, and 2) post-event time synchronization scheme. The ultra-low power accelerometer continuously monitors the vibration and trigger network when excessive vibrations are detected. The entire network of wireless smart sensors starts sensing through triggering and the post-event time synchronization is conducted to compensate for the time error on the measured responses. The results of this study highlight the potential of detecting the impact load and triggering the entire network, as well as the effectiveness of the post-event time synchronized scheme for compensating for the time error. A numerical and experimental study was carried out to validate the proposed sensing hardware and time synchronization method.

• The KIPS Transactions:PartD
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• v.18D no.4
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• pp.245-260
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• 2011

Mobile Devices, which are developed with the fast growing of the Internet, have flexible internet accessibility and can access the network anywere so that they can execute software applications. However, it is very challenging to deploy highly complex applications on mobile devices since they have limited resources. To overcome the limitation, researches on applying a concept of services to mobile applications have been proposed. Android is one of the popular mobile platforms and is designed to effectively execute mobile applications on the mobile devices having limited resources. Since service-based Android applications, which adopt a concept of services and Android platform, invoke remote services and are built with Android-specific components, they are much different from traditional software applications. Consequently, it is not straightforward to apply object-oriented (OO) analysis and design methods to developing service-based Android applications, although they have been frequently applied to developing traditional applications. In this paper, we present a process to develop service-based Android mobile applications, which extends a traditional OO development process. First, we raise design issues to be considered in developing service-based Android applications. Then, to solve the issues, we present detailed guidelines for essential phases of OO-based development process that are customized to service-based Android applications. Finally, to show applicability of the process, we perform a case study. The proposed design process is effectively utilized as a set of guidelines to develop service-based Android applications more systematically and effectively.

• KIPS Transactions on Software and Data Engineering
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• v.1 no.1
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• pp.43-54
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• 2012

This paper presents a new localization technique of an UGV(Unmanned Ground Vehicle) by matching ortho-edge images generated from a DSM (Digital Surface Map) which represents the 3D geometric information of an outdoor navigation environment and 3D range data which is obtained from a LIDAR (Light Detection and Ranging) sensor mounted at the UGV. Recent UGV localization techniques mostly try to combine positioning sensors such as GPS (Global Positioning System), IMU (Inertial Measurement Unit), and LIDAR. Especially, ICP (Iterative Closest Point)-based geometric registration techniques have been developed for UGV localization. However, the ICP-based geometric registration techniques are subject to fail to register 3D range data between LIDAR and DSM because the sensing directions of the two data are too different. In this paper, we introduce and match ortho-edge images between two different sensor data, 3D LIDAR and DSM, for the localization of the UGV. Details of new techniques to generating and matching ortho-edge images between LIDAR and DSM are presented which are followed by experimental results from four different navigation paths. The performance of the proposed technique is compared to a conventional ICP-based technique.

• Proceedings of the Korea Inteligent Information System Society Conference
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• 2000.11a
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• pp.257-266
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• 2000

산업 및 가정용 기기들이 점차 복잡해짐에 따라 다양한 공학 분야의 해석 기술을 동시에 고려하면서 이들 원리를 적용한 최적의 설계를 결정하는 방법론의 필요성이 대두되고 있다. 다분야통합최적설계 또는 MDO(Multidisciplinary Design Optimization)라 일컫는 새로운 기술은 이러한 필요에 대응하는 기술로서 국내외적으로 활발한 연구가 진행되고 있다. 이러한 MDO 기술을 구현하는 소프트웨어와 하드웨어 복합 체계를 MDO 프레임웍(framework)이라 한다. 일반적으로 프레임웍이란 실제 응용프로그램의 용도에 맞는 주문제작(customization)이 가능한 일종의 전단계 프로그램이라 할 수 있다 MDO 프레임웍은 설계 및 해석 도구들간의 인터페이스를 제공하고, 이들 도구들이 사용하는 설계 데이터를 효율적으로 공유할 수 있도록 지원하여, 설계 작업을 정의, 실행, 관리하는 역할을 한다. 이러한 MDO 프레임웍은 설계 작업을 통합적으로 관리하고 자동화하여 설계 도구간의 데이터 전달과 변환에 소묘되는 설계자의 부담을 경감시키며 다분야 전문가가 참여하는 공통 작업 환경을 제공함으로써 설계 효율성을 증진시킨다. 본 논문에서는 이러한 효용을 달성하기 위한 MDO 프레임웍(framework)을 제시하고 프레임웍 설계의 논리적 근저와 타당성을 밝힌다. 본 논문에서 제안하는 다분야 통합 최적화를 위한 분산형 지능 시스템인 DisMDO는 사용자가 GUI를 동해서 편리하게 다분야통합최적화 문제를 해결할 수 있도록 지원하며, 제공되는 스크립트 언어를 동해서도 이를 정의할 수 있도록 지원하여 일괄처리도 가능하도록 한다. 또한, 집중화된 데이터베이스를 관리하여 다분야 전문가들이 공통의 데이터를 안전하게 공유할 수 있도록 지원하며, 외부에서 제공되는 해석 도구나 최적화 모듈을 손쉽게 프레임웍에 통합시킬 수 있도록 하는 인터페이스 제작기(factory) 기능을 제공한다.ackscattering spectroscopy, X-ray diffraction, secondary electron microscopy, atomic force microscoy, $\alpha$-step, Raman scattering spectroscopu, Fourier transform infrared spectroscopy 및 micro hardness tester를 이용하여 기판 bias 전압이 DLC 박막의 특성에 미치는 영향을 조사하였다. 분석결과 본 연구에서 제작된 DLC 박막은 탄소와 수소만으로 구성되어 있으며, 비정질 상태임을 알 수 있었다. 기판 bias 전압의 증가에 따라 박막의 두께가 감소됨을 알 수 있었고, -150V에서는 박막이 거의 만들어지지 않았으며, -200V에서는 기판 표면이 식각되었다. 이것은 기판 bias 전압과 ECR 플라즈마에 의한 이온충돌 효과 때문으로 판단되며, 150V 이하에서는 증착되는 양보다 re-sputtering 되는 양이 더 많을 것으로 생각된다. 기판 bias 전압을 증가시킬수록 플라즈마에 의한 이온충돌 현상이 두드러져 탄소와 결합하고 있던 수소원자들이 떨어져 나가는 탈수소화 (dehydrogenation) 현상을 확인할 수 있었으며, 이것은 C-H 결합에너지가 C-C 결합이나 C=C 결합보다 약하여 수소 원자가 비교적 해리가 잘되므로 이러한 현상이 일어난다고 판단된다. 결합이 끊어진 탄소 원자들은 다른 탄소원자들과 결합하여 3차원적 cross-link를 형성시켜 나가면서 내부 압축응력을 증가시키는 것으로 알려져 있으며, hardness 시험 결과로 이것을 확인할 수 있었다. 그리고 표면거칠기는 기판 bias 전압을 증가시킬수록 더 smooth 해짐을 확인하였다.인하였다.을 알 수 있었다. 즉 계면에서의 반응에 의해 편석되는 Ga에 의해 박막의 strain이 이완되면, pinhole 등의 박막결함

• Proceedings of the Korea Inteligent Information System Society Conference
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• 2000.11a
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• pp.407-416
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• 2000

국방 부문에 종사하는 관리자들은 국방정보시스템 사업관리에 있어서 최신정보기술에 대한 기본적인 사항은 알고있어야 효율적이고 효과적이며 성공적인 사업관리를 진행할 수 있을 것이다. 국방 부문에 종사하는 관리자들이 저비용 고효율의 국방정보시스템을 건설하고 운영 유지관리 하기 위하여 알아야 할 핵심 및 최신정보기술은 크게 인공지능기술, 멀티미디어 정보화 기술, 가상현실 기술, 시뮬레이션 기술, 텔레프레즌스 기술, 나노테크놀로지 기술, 데이터베이스 기술, 병렬처리 기술, 로봇공학 기술, 소프트웨어 공학에 관련된 기술 등이 있다. 그러나 국방부문에 종사하는 정보통신 전문 인력을 제외한 관리자들이 국방관련 사업관리를 수행하면서 정보기술에 대한 이해 수준이 비교적 낮기 때문에 효율적으로 국방사업을 준비, 계획, 추진하기 어려운 실정이다. 따라서 국방부문에 종사하는 관리자들이 정보기술을 알기 쉽게 이해할 수 있도록 국방부문 핵심지능형정보기술 발전 및 군 활용방안을 이해하기 쉽도록 작성하며 효율적인 사업관리가 이루어질 수 있는 방안을 연구하였다. 본 논문은 국방부문핵심 지능정보기술 식별 및 활용방안을 연구하여 핵심적으로 식별된 사항들을 우리 국방부문의 $C^4$I(지휘, 통제, 통신, 컴퓨터시스템)시스템, 내장형 무기시스템, 각종 교육훈련 정보시스템, 자원관리 정보시스템 등에 어떻게 적용할 것이며 적용시 기대효과는 무엇인가를 제시토록 하여 국방부문에 종사하는 관리자들이 각종 국방사업을 조정, 통제, 확인, 감독, 준비/계획하면서 참고하여 저비용 고효율의 국방관련 각층 사업을 관리할 수 있는 능력을 배양시키도록 연구를 수행하였다. 국방관련 각종 사업을 관리할 수 있는 능력을 배양시키도록 연구를 수행하였다. 국방부문 핵심지능정보기술 발전 및 활용 방안에 포함될 주요 내용을 요약하여 제시하였다.의 경향성을 나타내는 오차 주기(error cyc1e)를 이용함으로써 고객들의 수요의 경향성을 좀 더 세밀한 부분까지 파악할 수 있게 해 준다.ction, secondary electron microscopy, atomic force microscoy, $\alpha$-step, Raman scattering spectroscopu, Fourier transform infrared spectroscopy 및 micro hardness tester를 이용하여 기판 bias 전압이 DLC 박막의 특성에 미치는 영향을 조사하였다. 분석결과 본 연구에서 제작된 DLC 박막은 탄소와 수소만으로 구성되어 있으며, 비정질 상태임을 알 수 있었다. 기판 bias 전압의 증가에 따라 박막의 두께가 감소됨을 알 수 있었고, -150V에서는 박막이 거의 만들어지지 않았으며, -200V에서는 기판 표면이 식각되었다. 이것은 기판 bias 전압과 ECR 플라즈마에 의한 이온충돌 효과 때문으로 판단되며, 150V 이하에서는 증착되는 양보다 re-sputtering 되는 양이 더 많을 것으로 생각된다. 기판 bias 전압을 증가시킬수록 플라즈마에 의한 이온충돌 현상이 두드러져 탄소와 결합하고 있던 수소원자들이 떨어져 나가는 탈수소화 (dehydrogenation) 현상을 확인할 수 있었으며, 이것은 C-H 결합에너지가 C-C 결합이나 C=C 결합보다 약하여 수소 원자가 비교적 해리가 잘되므로 이러한 현상이 일어난다고 판단된다. 결합이 끊어진 탄소 원자들은 다른 탄소원자들과 결합하여 3차원적 cross-link를 형성시켜 나가면서 내부 압축응력을 증가시키는 것으로 알려져 있으며, hardness 시험 결과로 이것을 확인할 수 있었다. 그리고 표면거칠기는 기판 bias 전압을 증가시킬수록 더 smooth 해짐을 확인

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.2
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• pp.1355-1363
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• 2015

In order to maintain customer voltage within allowable limit($220{\pm}13V$), tap operation of SVR(step voltage regulator) installed in primary feeder could be carried out according to the scheduled delay time(30 sec) of SVR. However, the compensation of BESS(battery energy storage system) is being required because the customer voltages during the delay time of SVR have a difficultly to maintain within allowable limit when PV system is interconnected with primary feeder. Therefore, this paper presents modeling of SVR to regulate voltage with the LDC(line drop compensation) method and modeling of BESS to control active and reactive power bi-directionally. And also, this paper proposes the coordination control modeling between BESS and SVR in order to overcome voltage problems in distribution system. From the simulation results based on the modeling with the PSCAD/EMTDC, it is confirmed that proposed modeling is practical tool for voltage regulation analysis in distribution system.

• Journal of KIISE:Software and Applications
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• v.34 no.7
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• pp.655-666
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• 2007

Reasoners using typical Tableaux algorithm such as RacerPro, Pellet have a problem in Tableaux algorithm large ABox reasoning. Researches to solve these Problems are dealt with Instance Store of University of Manchester which uses Tableaux algorithm based reasoner and DBMS and KAON2 of University of Karlsruhe using Disjunctive Datalog approach. An evaluation experiment for present reasoners is the experiment of TBox reasoning in most of Tableaux algorithm based one. The most of benchmarking tests in reasoning systems haven't done with ABox reasoning based Tableaux Algorithm but done with TBox reasoning based Tableaux Algorithm. Especially, rarely reported benchmarking tests in reasoners have been issued nowadays. Therefore, this thesis evaluates systems with theory of each reasoners for large ABox reasoning that becomes issues recently with typical reasoners. The large AoBx reasoning engine will be analyzed using Instance Store and KAON2 of Manchester University for large ABox processing. At the analysing method, LUBM(Lehigh University BenchMark), benchmarking test method, and it's test system will be introduced. In conclusion, I recommend appropriate reasoner in various environment with experiment result and characteristic of algorithm used for each reasoner.

• Journal of KIISE:Software and Applications
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• v.29 no.1_2
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• pp.42-52
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• 2002

Information extraction(IE) is a process of recognizing and fetching particular information fragments from a document. In previous work, most IE systems generate the extraction rules called the wrappers manually, and although this manual wrapper generation may achieve more correct extraction, it reveals some problems in flexibility, extensibility, and efficiency. Some other researches that employ automatic ways of generating wrappers are also experiencing difficulties in acquiring and representing useful domain knowledge and in coping with the structural heterogeneity among different information sources, and as a result, the real-world information sources with complex document structures could not be correctly analyzed. In order to resolve these problems, this paper presents an agent-based information extraction system named XTROS that exploits the domain knowledge to learn from documents in a semi-structured information source. This system generates a wrapper for each information source automatically and performs information extraction and information integration by applying this wrapper to the corresponding source. In XTROS, both the domain knowledge and the wrapper are represented as XML-type documents. The wrapper generation algorithm first recognizes the meaning of each logical line of a sample document by using the domain knowledge, and then finds the most frequent pattern from the sequence of semantic representations of the logical lines. Eventually, the location and the structure of this pattern represented by an XML document becomes the wrapper. By testing XTROS on several real-estate information sites, we claim that it creates the correct wrappers for most Web sources and consequently facilitates effective information extraction and integration for heterogeneous and complex information sources.