• Journal of Navigation and Port Research
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• v.30 no.5 s.111
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• pp.357-362
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• 2006

This paper describes two kinds of personal hand-held electronic devices to enhance marine leisure safety. The one is Radar response-type safety device triggering by the pulse signal from a commercial 9GHz-band Radar to provide quick search and rescue with combined civilian-government-military fleets. The other one is M-RFID (Marine Radio Frequency IDentification) based safety electronic device using 900MHz Tx/Rx with spread spectrum frequency hopping and GPS. Through the field tests at sea using Korea Coast Guard's warship the operating performances are verified. Further plan for practical use of each device was also discussed.

• Journal of the Korean Society of Fashion and Beauty
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• v.6 no.1
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• pp.16-20
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• 2008

Ubiquitous computing which is called, the innovation of the 21st Century is a core technology of next generation. RFID technology is noticed, and physical distribution, home network, telematics, like industry automatization are developed by using various technique. Particulary, They use RFID technology for fashion and beauty industry, So, supplying network management, physical distribution management and warehouse management are investigated for the automatization. What we have investigated so far, a traceability system is made of ubiquitous sensor network for monitoring fashion and beauty industry environment. The proposed system using EPC network can provide information of industrial products traceability quickly and efficiently. Moreover, this system with RFID Technology gives intelligence of distribution and record. In this paper, We recommend the vision of Ubiquitous convergence of fashion and beauty industry.

• Journal of Information Management
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• v.35 no.3
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• pp.75-107
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• 2004

The concept of "ubiquitous", which has been recently discussed in several industries, implies accessing a network using a computer from anywhere at anytime. The ubiquitous technology has been widely researched for distribution, construction, and medical treatments. Now, it has extended its application to libraries. The ubiquitous technology currently applied to a number of national libraries calls for a systematic study of an ubiquitous library. This thesis aims at presenting a model of introducing the ubiquitous technology to university libraries.

• Electronics and Telecommunications Trends
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• v.23 no.6
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• pp.32-37
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• 2008

최근 연구가 활성화되고 있는 능동형 전파식별(RFID) 및 유비쿼터스 센서 네트워크(USN) 기술은 그 파급효과가 매우 크고 방대하여 향후 미래 핵심 산업으로 자리잡을 것으로 예상되고 있다. 이러한 RFID 센서 태그 및 USN 센서 노드의 구동을 위해서는 태그나 노드 규격에 적합한 초소형이면서도 경량이고 장수명성을 가지는 전원소자 기술을 확보하는 것이 매우 중요하다. 현재는 이러한 RFID/USN용 센서 태그/노드에 일부 적용되어 그 가능성을 인정받은 전원소자 중 대표적인 것으로 리튬 이차전지와 필름형 일차전지가 있다. 본 고에서는 RFID/USN용 전원소자의 기본 개념 및 규격, 그리고 요구조건 등을 소개하고 국내.외 연구 및 특허 동향과 시장전망 등을 분석하여 향후 기술개발을 위한 참고자료로 삼았으면 한다.

• Proceedings of the Korean Information Science Society Conference
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• 2005.07a
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• pp.838-840
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• 2005

그동안 업무 전산화 차원에서 정보화를 추진해 오던 대학들이 최근 디지털 캠퍼스 구축의 일환으로 온라인 학사행정 시스템, 모바일 캠퍼스, 전자도서관 등을 잇따라 선보이며 정보화 영역을 넓히고 있다. 이러한 유비쿼터스의 대열에서 핵심기술로 전파식별(RFID, Radio Frequency IDentification)과 함께 U-센서네트워크가 두각을 나타내고 있다. 본 논문에서는 현재 두각을 나타내고 있는 RFID태그 시스템을 기반으로 ERP를 도입한 행정업무의 통합시스템 구축 및 디지털 도서관 시스템, 다양한 서비스 제공이 가능한 스마트카드 시스템 등 U-캠퍼스 구축을 위한 통합관리시스템 모텔을 제안하고자 한다. 통합관리시스템은 교육기관의 노동집약적이던 시스템에서 벗어나 투명하고 효율적인 행정관리와 원스톱 서비스 제공을 통해 보다 질 높은 교육환경을 제공할 수 있으며 사용자는 요구와 환경에 맞는 개인화$\cdot$지식화된 지능형 교육 서비스를 받을 수 있다.

• Proceedings of the Korea Information Processing Society Conference
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• 2009.11a
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• pp.449-450
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• 2009

사용자의 인터넷 소비성향을 파악하고 그에 적응적인 인프라 리소스를 제공하는 일은 네트워크 설계/관리자나 인터넷 서비스 공급자(ISP)들에게는 주요 관심사이다. 이러한 분석은 한정된 네트워크 자원을 보다 적절한 지점에 효율적인 방식으로 투자하도록 도와준다. 본 논문은 각종 인터넷 서비스를 활용하는 사용자들의 서비스(각종 인터넷 어플리케이션) 소비성향을 네트워크 트래픽 관찰만으로 파악할 수 있는 성향분류 척도를 제안한다. 아울러 베이지안 분류기를 사용하여 제안 척도를 활용한 사용자 성향 분류 방법을 함께 제시한다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.10 no.3
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• pp.419-429
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• 1999

Identifying the boundary of the effective receiving power of waves is one of the most important factors for cell optimization. In this paper, we introduce a propagation loss prediction model which yields highly accurate prediction in very complex areas as Seoul where a mixture of many large buildings, small buildings, broad streets, narrow alleys, rivers and forests co-exist in an irregular arrangement. This prediction model is based on neural networks trained on field measurement data collected in the past. Using these data along with 3-D digital elevation maps and vector data for building structures, we extract the parameter values which mainly affect the amount of propagation loss. These parameter values are then used as the inputs to the neural network. Trained neural network becomes the approximated function of the propagation loss model which generalizes very well and can predict accurately in the regions not included in training the neural network. The experimental results show a superior performance over the other models in the cells operating in the city of Seoul.

• Proceedings of KOSOMES biannual meeting
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• 2018.06a
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• pp.112-112
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• 2018

• Journal of Navigation and Port Research
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• v.45 no.1
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• pp.26-32
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• 2021

In ocean field, the spread of the Fourth Industrial Revolution based on information and communication technology requires high precision and stable PNT&D (Position, Navigation, Timing and Data). As the IMO (International Maritime Organization) and IALA (The International Association of Marine Aids to Navigation and Lighthouse Authorities) are requiring backup systems due to mitigate vulnerabilities and the increase of dependency on GNSS (Global Navigation Satellite System), Korea is conducting a research & development of R-Mode. An DGPS (Differentiate Global Positioning System) reference station that uses MF, an existing maritime infrastructure, and AIS (Automatic Identification System) base stations that use 34 integrity station and VHF will be utilized in this study to avoid redundant investment. Because there are radio shadow areas that display low signal levels in the west sea, the establishment of new R-Mode reference and integrity station will be intended to resolve problems regrading the radio shadow area. Because the frequency has a characteristic in that radio wave transmits well along the ground (water surface) in low frequency band, simulation and measurement were conducted therefore this paper to propose candidate sites for R-Mode reference and integrity station resulted through p wave's propagation characteristics analysis. Using this paper, R-Mode reference and integrity station can be established at appropriate locations to resolve radio shadow areas in other regions.

• The Journal of the Acoustical Society of Korea
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• v.13 no.6
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• pp.75-82
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• 1994

The ray paths and travel times of sound wave in the ocean depend on the physical properties of the propagating media. Ocean Acoustic Tomography(OAT), which is inversely estimate the travel time variations between fixed sources and receivers the physical properties of the corresponding media can he understood. To apply ocean survey technology by using the OAT, the tomographic procedure requires forward problem that variation of the travel times be identified with the variability of the medium. Also, received signals must be satisfied the necessary conditions of ray path stability, identification and resolution in order for OAT to work. The canonical ocean has been determined based on the historical data and its travel time and ray path are used as reference values. The sound speed of canonical ocean in the East Sea is about 1523 m/s at the surface and 1458 m/s at the sound channel axis(400m). Sound speeds in the East Sea are perturbed by warm eddy whose horizontal extension is more than 100 km with deeper than 200 m in depth scale. In this study, an acoustic source and receiver are placed at the depth above the sound channel axis, 350 m, and are separated by 200 km range. Ray paths are identified by the ray theory methed in a range dependent medium whose sound speeds are functions of a range and depth. The eigenray information obtained from interpolation between the rays bracketing the receiver are used to simulate the received signal by convolution of source signal with the eigenray informations. The source signal is taken as a 400 Hz rectangular pulse signal, bandwidth is 16 Hz and pulse length is 64 ms. According to the analysis of the received signal and identified ray path by using numerical model of underwater sound propagation, simulated signals satisfy the necessary conditions of OAT, applied in the East Sea.