• The Journal of Society for e-Business Studies
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• v.15 no.2
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• pp.167-189
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• 2010

As adopting ubiquitous technology into civil engineering, new city model is suggested called U-City. This paper proposes the framework of U-City management center to support effective services operation. The aims of the framework are to provide the development and operation environment for U-City services. Basically, these objectives are achieved by adopting the semantic web service technology to the framework. In this paper, OWL-S is mainly conducted to represent the description of U-City services. In addition, this paper insists that fine grained unit services are required to guarantee reusability, compatibility, and scalability of the services on U-City management center. The documentations conducted by OWL-S are provided as an example of service descriptions. At the last section, this paper also presents the architecture of U-City management center which enables automatic service discovery, selection, composition and interoperation.

• Journal of Advanced Navigation Technology
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• v.24 no.3
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• pp.224-231
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• 2020

An optical tracking plays an important role for measurement operation, as it is responsible for low altitude measurements that are difficult to obtain with radar systems. Since the existing optical tracking systems have not been developed in the proving ground itself so far, it is difficult to modify them to fit the environment of the proving ground. Also, they are designed as a vehicle-mounted type, so there is a limitation in selecting an optimal site. The in-house developed small optical tracking system is designed with a simple configuration to overcome these shortcomings and makes it possible for operators to operate the system at any place in the proving ground. In addition, there has been a need of developing small optical trackers by ourselves to be prepared for future research so that artificial intelligence (AI) can be applied to the optical tracking systems. In this paper, we described the design concept of the small optical tracker, the configuration of the components to implement the basic tracking function, and showed the results of the simulation to set the configuration of the equipment according to the characteristics of the flight targets.

• Journal of Internet Computing and Services
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• v.17 no.5
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• pp.17-23
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• 2016

Wireless sensor-actuator networks (WSANs) enhance the existing wireless sensor networks (WSNs) by equipping sensor nodes with an actuator. The actuators work with the sensor nodes and perform application-specific operations. The WSAN systems have several applications such as disaster relief, intelligent building, military surveillance, health monitoring, and infrastructure security. These applications require capability of reliable data transfer to act responsively and accurately. Biologically inspired modeling techniques have received considerable attention for achieving robustness, scalability, and adaptability, while retaining individual simplicity. In this paper, an epidemic-inspired algorithm for data dissemination with delay constraints while minimizing energy consumption in WSAN is proposed. The steady states and system stability are analyzed using control theory. Also, simulation results indicate that the proposed scheme provides desirable dissemination delay and energy saving.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2017.04a
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• pp.170-170
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• 2017

기후변화 따른 스마트팜 돈사 외부 환경의 변화에 대응하고, 사육 환경을 능동적으로 개선하기 위한 연구가 수행 중이다. 돈사 내 열전달 요소 간 상호 역학성 분석을 위해서 고려해야할 사항은 입기구, 보온 등, 열풍기, 단열제, 위치, 방향, 돈사의 연평균 온도, 습도, 연중 일사량, 가축의 열복사 등 상호 복잡하게 연관되어 있는 물리량이다. 돈사 전체 열손실, 자연발생 에너지량, 강제발생 에너지량, 난방용량 등을 고려한 순간 열부하 산정을 위한 여러 방법 중 우선적으로 CFD(Computational Fluid Dynamics)를 이용하였다. 순간 열부하 산정을 위한 해석 도구 선정에 있어서 다양한 유체 및 기체 전산 유체역학 Solver(Fluent, Open-FOAM, Blender)를 고려하였다. 공간 Mech를 수행하기 위한 도구로는 공개 소프트웨어 인 FreeFem++ 3.51-4 (http://www.freefem.org)를 이용하였다. 이 과정에서 일부 기체 (암모니아)의 농도를 난수로 변화시키는 기법을 적용하여 가상적으로 돈사의 환경을 Pseudo 시뮬레이션 하였다. 결과적으로 Fluent에 비하여 OpenFOAM을 이용하여 얻은 열유동의 방향(속도)과 크기 백터가 상대적으로 크게 나타났다. Fluent가 시계열 상에서 혼합 기체 물리량 변화를 무시할 수 있는 안정되고 균일한 환경에 적합하기 때문인 것으로 판단되었다. Blender의 경우 Lattice Boltzmann methods 과 Smoothed-particle hydrodynamics 방법을 이용한 유체/입자 동력학 모델링을 제공함에 있어 시각적 효과를 강조하는 기능에 중점을 두었다. Fluent와 Blender에서 제공하는 해석 연산 모듈의 정확성 검증을 위해선 공간 분해능을 높인 정밀 계측 시스템을 이용하여 검증할 필요가 있다. Open-FOAM를 이용한 열부하 분석 수행이 상대적으로 높은 절대값을 보이는 특성은 열부하 제어 시스템의 Overshoot를 유발할 가능성이 있으므로 이에 대한 해석 모델의 보정이 추가적으로 필요할 것이다. CFD의 한계인 시간 복잡도를 낮추고 상대적으로 높은 시계열 분해능을 확보할 경우 돈사 내 환기시스템에 맞는 소요 환기량 실시간 산정이 가능해지고 외부기상 및 돈사내부 복사열을 활용함과 동시에 돈군 순환에 상응하는 실시간 열부하 관리 시스템 도출이 가능할 것이다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.6C
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• pp.561-570
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• 2009

Ultra-wideband communication systems based on impulse radio have merits that are possible for the high data rate transmission, high resolution ranging are positioning system. Conventionally, in order to accomplish these features, the high-speed ADC (Analog to Digital Convertor) is necessary to apply radio determination system operating in time domain. However, considering low rate - wireless personal area network (LR-WPAN) aims to low-cost hardware implementation, the expensive ADC converting GHz sampling per second is not appropriate. So, this paper introduces a low complex AR (Auto Regressive) model based non-coherent ranging scheme operating in frequency domain with using low-speed ADC utilizing analog Voltage Control Oscillator (VCO) mode for the frequency domain transformation. To verify the superiority of the proposed ranging and location algorithm working in frequency domain, the suggested IEEE 802.15.4a TG channel model is used to exploit affirmative features of the proposed algorithm with conducting the simulation results.

• 한국공간정보시스템학회:학술대회논문집
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• 2005.05a
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• pp.189-194
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• 2005

현재 국가에서는 하천지도전산화사업 등의 성과물인 하천관련 DB의 활용 극대화를 위해 하천주제도구축사업을 시행중에 있다. 그 결과 요구도 높은 하천주제도의 항목이 결정되었으며, 이를 활용하기 위하여 GIS를 이용한 효율적인 하천주제도 관리 방법의 필요성이 증대되고 있다. 따라서 본 연구에서는 2002년 한국수자원공사의 '하천주제도사업계획수립'에서 정립한 하천주제도 데이터 모델을 활용하여 하천주제도의 효율적인 관리를 위하여 GIS를 활용한 시범 시스템을 개발하였다. 개발방법으로는 설계한 데이터모델을 적용하고, 하천관리지리정보시스템(RIMGIS) 및 향후 유통측면을 고려하였다. 이에 앞서 연구대상지역을 선정하였고, 모델을 기반으로 한 DB의 위하여 기 구축된 DB의 효과적 활용 방안을 제시하였다. 개발된 하천주제도 관리시스템은 하천주제도에 관련된 도형자료를 구축하고, 그에 대한 속성자료를 연계한 시스템 제작을 의미한다. 이를 위해 세부적으로 정의된 주제도를 기 구축된 RIMGIS 도형자료 및 속성자료, 하천정비기본계획, 수자원공사자료, 환경부자료, 건교부 자료, 문화관광부자료 등을 활용하여 하천주제도 관리시스템을 제작하였다. 아울러 하천주제도 구축에 앞서 설계한 하천주제도의 보델을 통하여 하천과 관련된 데이터와 수리 수문 입력변수를 산정하기 위한 전처리 및 후처리 과정이 동일 시스템 내에서 통합처리가 가능할 것이며, 하천에 대한 동적 모델링을 위한 기초 자료의 제공도 가능하리라 본다. 나아가 하천주제도 구축시 간단한 연산기능에서부터 다양한 응용정보를 요구하는 주제도에 대한 효율적인 구축 방안을 제공할 수 있을 것으로 사료된다. 또한 관리시스템을 활용하여 하천주제도의 관리 및 사용이 보다 효율적이며, 하천업무 담당자뿐만 아니라 일반인들의 이해를 돕고, 연구의 성과를 향상시킬 수 있다. 더욱이 이러한 하천주제도 관리시스템의 개발은 타 분야에 구축된 방대한양의 하천 관련 GIS데이터 등의 자료를 연계하여 기 구축데이터의 활용도를 제고할 수 있다.

• Journal of KIISE:Computing Practices and Letters
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• v.15 no.7
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• pp.500-504
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• 2009

A reliability of software is a type of nonfunctional requirement. Traditionally, a validation of the reliability is processed at the integration phase in software development life cycle. However, it increases the cost and the risk for the development. In this paper, we propose reliability analysis method based on mathematical analytic model at the architecture design phase of the development process as follows. First, we propose the software modeling methodology for reliability analysis using Hierarchical combined Queueing Petri Nets(HQPN). Second, we derive the Markov Reward Model from the HQPN based model. We apply our approach to the video conference system to verify the usefulness of our approach. Our approach supports quantitative evaluation of the reliability.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.37 no.2
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• pp.68-78
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• 2000

This paper suggests a new map-matching algorithm for matching traveling trace of vehicle, which is measured by GPS receiver, to the road of a digital map This eventually brings the Improvement of positioning accuracy of the vehicle with GPS receiver After representing the travelling vehicle's motion by state equations using Singer's model, the proposed map-matching algorithm places the position of a vehicle right on the road and also improves the positioning accuracy of the vehicle using a Kalman filter In the crossroad, since it is difficult to determine precisely a current travelling road, we take linear regression to the estimated values from Kalman filtering This gives the direction angle of turning vehicle, then we can determine the correct route direction after comparing with each route-direction angle at the intersection.

• Journal of The Korean Association of Information Education
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• v.10 no.2
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• pp.219-226
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• 2006

For the accurate creation of annotation information in a free-form annotation environment, the ambiguity that arises in the analysis stage between the geometric information and annotations needs to be resolved. Therefore, this This paper identifies, analyzes, and proposes presents solutions methods for the ambiguity that can occur between free-form marking and various contexts in XML-based annotation environment. The proposed method is based on context which includes various textual and structure information between free-form marking and annotated part. The proposed method show that the annotated portions areas included in the free-form marking information are more accurate, achieving more accurate exchange results amongst multiple users in a heterogeneous document environment. This study can be effectively applied to eLearning, Cyber-Class, and IETM

• Korean Journal of Construction Engineering and Management
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• v.1 no.2 s.2
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• pp.108-116
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• 2000

The absence of systematic project procedures in the domestic SOC projects has caused many problems. Therefore, it has been raised the needs for the effective project management of the projects which helps the participants to have systematic procedures at each phase of the SOC projects. The purpose of this research is to build the current model of procurement management process for the airport facilities and to derive inherent problems, and the building direction of the effective procurement management is suggested for the future research. The result of this research could be used for delivering the effective SOC projects and for establishing interrelationships between procurement and other phases of the projects for the integrated project management. The procurement process of the Inchon International Airport was investigated and the as-is model was built. Through the analysis of the as-is model, and the questionnaires and the interviews with the participants of the SOC projects, the problems of the current procurement process has been derived.