• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.123-123
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• 2019

최근 기후변화로 인해 중국, 한국, 일본, 몽골 등을 포함한 동아시아 지역은 태풍, 가뭄, 홍수와 같은 자연재해의 발생 빈도가 증가하고 있는 추세이다. 중국의 경우 2017년 극심한 가뭄으로 1,850만 (ha)의 농작물 피해가 발생하였으며, 몽골 또한 2017년 4월 이후 극심한 가뭄으로 사막화가 급속도로 진행되고 있다. 위성 기반의 강우 자료는 공간과 시간 해상도가 높아짐에 따라 지상관측소 강수량 자료의 대체 수단으로 이용되고 있다. 본 연구에서는 Climate Hazards Groups InfraRed Precipitation with Station (CHIRPS), Precipitation Estimation From Remotely Sensed Information Using Artificial Neural Networks-Climate Data Record (PERSIANN-CDR), Global Precipitation Climatology Centre (GPCC) 강우 위성 자료를 활용하여 기상학적 가뭄지수인 표준강수지수 (Standardized Precipitation Index, SPI)를 산정하였다. 시간 해상도는 월별 영상을 기준으로 2008년부터 2017년까지 지난 10년간의 데이터를 이용하였으며, 각각 격자가 다른 위성영상을 기존 기상관측소와 비교하였다. 피어슨 상관계수 (Pearson Correlation Coefficient, R)를 활용하여 강우 위성 영상과 지상관측소의 상관관계를 분석하고, 평균절대오차 (Mean Absolute Error, MAE), 평균제곱근오차 (Root Mean Square Error, RMSE)를 통해 통계적으로 정확도를 분석하였다. 인공위성 강수량 자료는 미계측 지역이 많은 곳이나 측정이 불가능한 지역에 효율성 측면에서 중요한 이점을 제공할 것으로 판단된다.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2007.04a
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• pp.465-468
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• 2007

This paper addresses the scheme for transmitting Data and TDM signals based on E-PON. E-PON technology, that combines low-cost Ethernet technology and optical fiber infra-structure, has been appeared as a solution of next generation access network. The transmission speed of E-PON is 1Gbps and symmetric in both direction, such as downstream and upstream. Therefore, it is possible to save the cost through sample network architecture, efficient operation, and low maintenance cost of optical IP Ethernet network. By adding TBMoIP(Time Division Multiplexing over Internet Protocol) module to this E-PON system, and implementing QoS(Quality of Service) control function, this system can provide data and TDM service efficiently.

• Journal of the Korea Computer Industry Society
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• v.5 no.5
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• pp.771-780
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• 2004

The demands of users have become variety and diversification by the conversion of application to Web environment from C/S(Client/Server) enviroment as well as by the development of application which puts into practie an information technology with the advance of internet basic technology. Therefore if it attempt to satisfy their all demands, the services like a real time batch processing are faced with a difficult obstacle that the limited existing system cannot manage. Finally it is come to a conculsion that the extension of system or the induction of new system is necessary in order to solve this problem according to a ragular tuning and an examination about infra of web environment. This thesis intends to propose about inter- relation and improvement plan as well as considerable facts in case of the introduction of system through the efficiency analysis process of the system.

• Journal of Advanced Navigation Technology
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• v.13 no.2
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• pp.214-223
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• 2009

In this paper, we analysed and simulated the high speed mobile wireless channel for IEEE802.11p WAVE/DSRC standard draft. IEEE802.11p working group measured and suggested 6 channel model for WAVE/DSRC systems which is used for vehicle to vehicle or vehicle to infra communication. However, the models only provides numerical model, it did not provide Computer based software simulation model. So it can not be used directly for performance estimation of WAVE system. In this paper we suggested simulation technique of WAVE channel simulation which is developed S/W based WAVE channnel simulator. The simulation results for PSD, LCR, and AFD are also obtained, which can be used for performance estimation of IEEE802.11p based vehicular communication system.

• Archives of design research
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• v.15 no.1
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• pp.93-100
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• 2002

The University's web library is a form of library that enables to deal with information about searching loaning, returning of books or data housed in it through web. With the advent of the network and multimedia following the entrance to an information-oriented society, we are experiencing a big change in how to communicate and acquire information. Massive multimedia information transmitted by image and moving picture through the network, made it possible to overstep the limit of the physical gap between information suppliers and users. Despite this important role, it is accompanied by problems such as copyright, scarcity of recognition, paralysis of infra, technical matters and reliability which demand development. In this thesis, according to the State University Evaluation Standards, search node and user interface by system used in 20 different universities possessing web-based library sites were compared are analysed. On the basis of this, an experimental user interface for web-based University libraries was produced, and various questionnaires and data leer this produced interface were collected, classified and analyzed. With the application of the results for the work above to the general search system interface of the web-based library, we proposed a new user interface that contains the following functions, such as location and loan condition of books, search frequency and steps for purchasing books inside the web library.

• Korean Chemical Engineering Research
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• v.53 no.2
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• pp.164-173
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• 2015

This study aims to design energy supply systems from various energy sources for transportation sectors and comparatively analyze the life cycle cost of different scenario-based systems. For components of the proposed energy supply system, we consider a typical oil refinery, byproduct hydrogen system, renewable energy source (RES)-based electric generation system and existing electricity grid. We also include three types of vehicles in transportation sector such as internal combustion engine vehicle (ICEV), electric vehicle (EV), fuel cell vehicle (FCV). We then develop various energy supply scenarios which consist of such components and evaluate the economic performance of different systems from the viewpoint of life cycle cost. Finally we illustrate the applicability of the proposed framework by conducting the design problem of energy supply systems of Jeju, Korea. As the results of life cycle cost analysis, EV fueled by electricity from grid is the most economically feasible. In addition, we identify key parameters to contribute the total life cycle cost such as fuel cost, vehicle cost, infra cost and maintenance cost using sensitivity analysis.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.10a
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• pp.520-524
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• 2003

Problem of compatibility, content protection, contents circulation ok. was caused between contents offerer and consumers by indiscreet right technical development about digital contents. The MPEG committee proposed MPEG-21 framework for these problem solution and for right managing in MPEG-21 inside XML(eXtensible Markup Language)'s structure REL(Right Expression Language) that is a right expression language propose. Contents protection, circulation, standard right information representation for administration that is reasonable and is the transposition enemy mutually by REL's use doing based on this MPEG-21 were available. Fast correspondence about new technology is necessary circumstance because present MPEG-21 is in study step and REL edit solution as infra technology is required. Also, development of REL document edit system is required mere because this REL document edit has difficulty in edit except expert with MPEG-21 Framework. In this paper, designed and embody about REL document mastication system that right creation and edit are available efficiently about contents easily without comprehension of MPEG-21 framework and client system that present consumption method of REL right document.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.11
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• pp.2107-2112
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• 2006

As growing up of elderly population, the interesting on healthcare system in normal life using W is increasing. An integrated u-healthcare service architecture with IEEE 802.11 and IEEE 802.15.4 based sensor network and code divisi(m multiple access(CDMA) public mobile telecommunication networks was designed and developed. Sensor nodes with electrocardiogram(ECG), body core temperature sensors are attached on the patients' body. The healthcare parameters are transferred to web server via CDMA mobile network or through existed LAN network. The existed LAN network is suggested to be used for continuous monitoring of patient's health status in hospital while mobile networks can be used for general purpose at home or outdoor where infra networks unavailable. This system enable healthcare personal to be able to continuously access, review, monitor and transmit the patients information whereever they are, whenever they want. And immediately check their status by using cellular phone and obtain detail information by communication with medical information server through CDMA. By using this developed integrated u-healthcare service architecture, we can monitor patients' health status for 24 hours.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.10a
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• pp.459-462
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• 2008

By using RFID technology in order to manage public traffic management, RFID system and middleware software with PXA255 ARM chip is developed and is capable of operating the traffic card. The developed RFID system consists of 13.56MHz RFID R/W, wireless LAN (IEEE802.11.a/b), Wibro (IEEE802.16), TFT-LCD to display information, and embedded system to collect a charge information, etc. By applying developed system, basic infra-structure capable of supporting various service of u-Traffic can be effectively applied.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.1D
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• pp.1-6
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• 2011

The Context-Awareness technology which can provide the appropriate information to the human after estimating a lot of information exceeds the time and space in the ubiquitous environment is being developed now. GIS (Geographic Information System) and LBS (Location Based Services) based context awareness is one of these kinds of technology. The context awareness based transfer guide service which can provide useful information, according to the different information which was got from different sensors which were set in different places, to the pedestrian who is using the transfer center will be introduced in this paper. About the result of the service prototype which was tested in test-bed, the context awareness information such as the inside location and density calculation's accuracy is 90%, and the response time of the service is in 10 seconds, and also, the reliability will be higher if more advanced based infra will be used, so it is consider that it can be used to provide service enough.