• Journal of Satellite, Information and Communications
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• v.12 no.4
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• pp.120-124
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• 2017

This paper describes the product of search and rescue system with dynamic model. This spread spectrum system based new standard of COSPAS-SARSAT is results of RF signal generation and transmission. we will test performance evaluation which implement signal process adapting Dynamic model and we will adapt the CAF model using TDOA and FDOA relationship.

• Proceedings of the Korea Technology Innovation Society Conference
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• 2005.10a
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• pp.503-510
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• 2005

전체 인구대비 가입률이 $80\%$에 육박하는 이동통신서비스를 기반으로 국내에서 무선인터넷은 눈부시게(outstanding) 성장을 거듭하고 있다. EV-DO를 중심으로 제 3세대 이동통신 기술의 진화와 카메라 폰 등의 최신의 무선 단말기 보급, 게임 및 SMS, MMS, LBS 등의 콘텐츠 보급 등이 무선인터넷 성장의 원동력(growth factors)으로 작용하고 있다. 본 연구에서는 정보기술수용모형(TAM)을 기반으로 국내에서 무선인터넷 확산 영향요인을 규명하기 위한 탐색적인 목적으로 수행되었다. 이를 위하여 무선인터넷의 네트워크 품질, 콘텐츠 품질, 단말기 품질, 초기 비용, 이용요금, 유용성, 이용용이성, 사회적 영향, 이용태도, 이용행동 등에 관한 자료를 설문 조사를 통해 수집하였다. 그리고 구조방정식을 통하여 각 요인들간의 인과관계를 실증적으로 검증하였다. 그리고 국내에서 무선인터넷에 대한 이용의향을 바탕으로 고객군을 세분화하고 집단의 특성을 파악하였다.

• Proceedings of the Korean Society of Computer Information Conference
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• 2014.07a
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• pp.509-510
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• 2014

본 연구 개발에서는 육로가 아닌 바다에서의 해양 환경 상태와 어선의 운행 시 사고 영상을 저장 확인할 수 있는 소형 어선용 영상저장 및 환경 데이터 저장 Set-top Box를 개발하고자 한다. 소형어선들은 매우 필요하나 장비의 고가로 인하여 구축하기가 어려워 저가의 장비의 개발은 필수적이다. 이를 기반으로 현재 해양경찰에서 사용하고 있는 무선통신 방식과 접목하여 사고나 위험한 상황 시 해양경찰이나 관제센터로 영상 및 데이터를 전송하여 해양에서 얻을 수 있는 각종 해양 환경정보 및 각 선박들의 안전에도 기여하고자 한다.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.23 no.2
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• pp.1-14
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• 2024

The most optimal route-search algorithm thus far has introduced a method of applying node labels and link labels. Node labels consider two nodes simultaneously in the optimal route-search process, while link labels consider two links simultaneously. This study proposes a turn-label-based optimal route-search technique that considers two turns simultaneously in the process. Turn-label-based optimal route search guarantees the optimal solution of dynamic programming based on Bellman's principle as it considers a two-turn search process. Turn-label-based optimal route search can accommodate the advantages of applying link labels because the concept of approaching the limit of link labels is applied equally. Therefore, it is possible to reflect rational cyclic traffic where nodes allow multiple visits without expanding the network, while links do not allow visits. In particular, it reflects the additional cost structure that appears in two consecutive turns, making it possible to express the structure of the travel-cost function more flexibly. A case study was conducted on the metropolitan urban railway network consisting of transportation card terminal readers, aiming to examine the scalability of the research by introducing parameters that reflect psychological resistance in travel with continuous pedestrian transfers into turn label optimal path search. Simulation results showed that it is possible to avoid conservative transfers even if the travel time and distance increase as the psychological resistance value for continuous turns increases, confirming the need to reflect the cost structure of turn labels. Nevertheless, further research is needed to secure diversity in the travel-cost functions of road and public-transportation networks.

• Proceedings of the Korean Information Science Society Conference
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• 2006.10d
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• pp.549-552
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• 2006

국내 유무선 인터넷은 세계 시장과 통신트랜드를 주도할 정도로 이용자 규모, 서비스 다양성, 서비스 수용성 측면에서 커다란 성과를 나타내며 이는 선순환 구조를 통해 단말기, 장비, 콘텐츠 산업의 경쟁력을 강화시키는데 기여하고 있다. 또한 국내 통신시장은 와이브로와 HSDPA로 대표되는 광대역 무선인터넷 시대를 선도할 것으로 기대되고 있다. 본 글에서는 전국 일반인을 대상으로 시장조사 결과를 바탕으로 유무선 인터넷의 이용행태를 파악하고 광대역 무선인터넷에 대한 니즈를 탐색하고자 하였다. 분석결과, 국내 유무선 인터넷 시장은 10~20대의 학생층뿐만 아니라 30대 이상의 화이트 칼라로 이용층으로 확대되며 이 계층이 광대역 무선인터넷의 핵심 이용자군으로 잠재력을 지닌 것으로 나타났다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.5A
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• pp.611-617
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• 2000

Asynchronous mode W-CDMA system is kmown to be quite appropriate to the next generation mobile communication system, especially in a non-homogenious cellular architecture. In this case, however, each base station needs to use different spreading code for identification, so it is a demeanding task for a mobile terminal to find the best cell site and get an accurate code synchronization at the beginning of a communication. Since slow acquisition of a base station could mean the failure of initiation, a fast algorithm to accelerate the cell search process is essential. In this paper, a new cell search algorithm based on the binary code position modulation within the code block is proposed. Different cell sites are identified by different hopping code sequences, andeach position modulation is performed by the hopping code. The proposed algorithm is proved to make the cell search time in most places in a cell much shorter than the previous algorithms, and to make the receiver implementation simpler.

• Journal of KIISE:Computing Practices and Letters
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• v.12 no.1
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• pp.66-77
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• 2006

In this paper, we researched the searching and tracking locations of a home resident using ON/OFF switches and sensors and designed a remote monitoring system. As an implementation environment, this system is developed on the base of the distributed object group framework we have developed from previous works. In order to trace the moving locations of a home resident, we firstly showed a home structure which attaches ON/OFF switches and sensors to home appliances and indoor facilities being fixed in home. Whenever a home resident opens/closes these objects, the signals operated from ON/OFF switches and sensors are sent to a home server system. In this time, the real locations of ON/OFF switches and sensors that the signals are being occurred must be the current location that he/she stays. A home server system provides the functionalities that map the real location of a resident in home to virtual location designed on remote desk-tops or terminals like PDAs, and that construct a healthcare database consisted of moving patterns, moving ranges, momentum for analyzing the given searching locations and times Finally, this system provides these information for remotely monitoring services.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.2
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• pp.89-94
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• 2011

Today, the utilization of communication devices is being increased including information terminals, cell phones, handheld personal digital assistants (PDA) caused by the development of information and communication technology. The development of information and services is speeding up, whereas most communication devices have provided a inefficient hierarchical menu and sequential searching structure. In this study, the Adaptive User Interface is applied to the Bus Information Terminal(BIT) which is one of communication equipment installed in the bus stop. It will be based on analysis of unspecified individuals' preferences and user's directly personalization in the BIT prototype. We expect the results of this study to be possible to provide users with efficient and convenient information acquisition and contribute to the development of public transport use by improving the accessibility and usability of BIT.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.9A
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• pp.694-701
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• 2003

In this paper, we present a hardware structure and new features of a smart antenna BTS (Base Transceiver Station) for CDMA2000 1X system. The proposed smart antenna BTS is a composite system consisting of many subsystems, i.e., array antenna element, frequency up/down converters, AD (Analog-to-Digital) and DA (Digital-to-Analog) converters, spreading/despreading units, convolutional encoder/Viterbi decoder, searcher, tracker, beamformer, calibration unit etc. Through the experimental tests, we found that the desired beam-pattern in both uplink and downlink communications is provided through the calibration procedure. Also it has been confirmed that the adaptive beamforming algorithm adopted to our smart antenna BTS is fast and accurate enough to support 4 fingers to each user. In our experiments, commercial mobile terminals operating PCS (Personal Communication System) band have been used. It has been confirmed that the smart antenna BTS tremendously improves the FER (Frame Error Rate) performance compared to the conventional 2-antenna diversity system.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.41 no.10
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• pp.95-104
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• 2004

This paper propose a motion estimator architecture to reduce the power consumption of the most-power-consuming motion estimation method when designing multimedia SoC with deep submicron technologies below 0.13${\mu}{\textrm}{m}$. The proposed architecture considers both dynamic and static power consumption so that it is suitable for large leakage process technologies, while conventional architectures consider only dynamic power consumption. Consequently, it is suitable for mobile information terminals such as mobile videophone where efficient power management is essential. It exploits full search method for simple hardware implementation. It also exploits early break-off method to reduce dynamic power consumption. To reduce static power consumption, megablock shutdown method considering power line noise is also employed. To evaluate the proposed architecture when applied multimedia SoC, system-level control flow and low-power control algorithm are developed and the power consumption was calculated based on thor From the simulation results, power consumption was reduced to about 60%. Considering the line width reduction and increased leakage current due to heat dissipation in chip core, the proposed architecture shows steady power reduction while it goes worse in conventional architectures.