• Journal of Advanced Navigation Technology
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• v.13 no.5
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• pp.677-683
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• 2009

In this study, we designed and implemented testbed for localization algorithm by using a area reduction method in outdoor environment. The proposed algorithm used 3 steps of area reduction method, which estimated blind nodes position. Also, we have experimented with using a Zigbee module for 5 fixed reference nodes and 4 blind nodes in sensor field of $60m{\times}23m$. The results show that our algorithm is improved the localization accuracy even at the number of ref. node is fixed and the number of blind node is increased. In future research, we will be adding the function of seamless localization in indoor and NLOS(non-line of sight) environment.

• Journal of the Korean Society of Propulsion Engineers
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• v.14 no.6
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• pp.38-44
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• 2010

The shock wave and boundary layer interaction patterns in an over-expanded rocket nozzle are associated with the production of undesirable side-forces during the start-up and shut-down processes of the engine. In the present work, a computational study is carried out to investigate the effect of the transient nozzle pressure ratio (NPR) on the flow fields inside the nozzle. The unsteady, compressible, axisymmetric, Navier-Stocks equations with SST k-${\omega}$ turbulence model are solved using a fully implicit finite volume scheme. NPR is varied from 2.0 to 10.0, in order to simulate the start-up and shut-down processes of the rocket engine. It is observed that the interaction patterns and the hysteresis phenomenon strongly depend on the time variation of NPR, leading to significantly different characteristics in the lateral forces.

• Journal of Intelligence and Information Systems
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• v.15 no.4
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• pp.141-158
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• 2009

The requirements of knowledge customization have increased as information resources have become more various and the numbers of the resources are increased. Even if the method for collecting the information has improved like Really Simple Syndication (RSS), information users are still struggling for extracting and customizing the required information through the Web. To reduce the burden, we offer the dynamic knowledge customization framework by using ontology-based CBR. The framework consisting of three phases is comprised of the conversion phase of web information as a machine-accessible case, the extraction phase to find a case appropriate for information users' requirements, and the case customization phase to create knowledge depending on information user's requirements. Newly, the dynamic and intensity-based similarity is adopted to support timely dynamic change of users' requirements. The framework has adopted to create traveler's knowledge to the level users wanted.

• Journal of Korea Multimedia Society
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• v.12 no.10
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• pp.1436-1449
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• 2009

The value of sensing information is decided according to positions of sensor nodes, which are very important in sensor networks. In this paper, we propose a method that estimates positions of nodes by using adjacent node information and received signal strength in a sensor network. With the proposed method, we can find positions of nodes easily because we use information that nodes have. Moreover, we can find distribution easily for all the nodes because we can measure a relative position for a node whose position is not known based on anchor nodes whose positions are already known. We utilized Use case diagram, activity diagram and State machine diagram among several diagrams of UML to implement proposed method in sensor networks that is dynamic system. We can understand exact flow for each function of the proposed method in node position estimation system can be implemented easily. And we can be confirmed that the position of estimated nodes has a little error.

• Proceedings of the KSRS Conference
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• 2007.03a
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• pp.92-96
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• 2007

전라남도 국민참여형 위성영상 블로그 시스템은 2006년도 행정자치부 자치단체정보화지원사업의 일환으로 구축된 것으로서， 사용자가 고해상도 위성영상 위에 직접 자신의 글，사진， 동영상을 올리고，이를 다른 사용자나 시스템과 공유할 수 있도록 구축된 시스템이다. 본 시스템이 궁극적으로 구현하고자 했던 과제는 다음과 같다. (1)지리정보 혹은 기타 정보의 고정성을 탈피하고，(2)지리정보와 멀티미디어 자료의 효율적 통합을 통해 geoUCC를 구축하며，(3)사용자의 참여를 통한 지리정보 제공 방식의 쌍방향성을 구현하여，(4) 사용자를 일방적 자료 활용자에서 자료 생성자로 발전시키고 궁극적으로는 자치단체와 국민 간 새로운 방식의 소통 방식을 생성하는 것이다. 본 시스템 구축의 결과로서 본 시스템에서 일반 국민에게 서비스되는 내용은 다음과 같다. (1) 전라남도 전역의 1m급 고해상도 위성영상의 대국민 서비스，(2)전라남도 전역에 대한 지번 단위까지의 주소 검색 서비스，(3)웹 상에서의 실시간 3차원 GIS 서비스，(4)Web2.0의 철학을 반영한 RSS, Trackback 및 Tag 검색 기능，(5)사용자가 직접 고해상도 위성영상 위에 자신의 글， 사진，동영상，홈페이지 등을 올릴 수 있는 "위성영상 블로그 쓰기 기능"，(6)국내 거의 모든 포털 사이트의 블로그와 홈페이지를 지원하는 시스템 연계(퍼가기) 기능 등이다. 결론적으로 본 시스템의 사용자는 고해상도 위성영상 기반의 지도 위에 자신의 여행기，사진， 동영상을 올림으로써 자신만의 사용자제작콘텐츠(UCC)를 생성할 수 있을 뿐만 아니라， 이를 다른 사용자와 공유， 활용함으로써 실질적인 쌍방향，참여형 지리정보시스템을 이용하게 된 것이다.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.6
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• pp.241-249
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• 2012

In the many countries, research about ultra wideband wireless transmission technique is widely studied for efficient utilization of frequency resource due to a sudden increase of demand of frequency resource all over the world. The ultra wideband communication system has the some specific advantages. First, it can transmit data with high speed, second short transmission range can increase the frequency reuse rate, and finally it has high security property. However, there is a interference between ultra wideband system and other communication system but study to solve this problem is insufficient. To efficient utilization of limited frequency resource, a novel frequency avoidance technique and setup the standardization of frequency interference must need. So, the purpose of this paper is that increases communication efficiency of microwave communication systems to analyze the technical trends for transmission of the low power device, and to research the implementation and technical research of wireless access network technique of wideband communication systems.

• PNF and Movement
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• v.15 no.2
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• pp.115-124
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• 2017

Purpose: Researchers found that blocks of evidence-based practice (EBP) implementation lacked opportunities for EBP education. The study found that physical therapists had negative views of research as well as their roles in EBP, lacked confidence in EBP, and had limited access to web-based materials. The purpose of this study was to highlight the importance of information research technology for efficient EBP in a clinical environment. Methods: The web-based information research technologies that should be used for sustainable EBP include: the clinical practice guideline (CPG) and PubMed's My NCBI service. Journal mailing services and other academic information sources should also be used to gather information from RSS feeds. An EBP library or archive must be created. A site that provides EBP-specific information is also needed. Results: We should usually do EBP. Practitioners must learn and use information technologies that will help them improve their EBP skills. Conclusion: Facilitating EBP implementation and building an EBP system require related education as well as a practical work environment and equipment. However, the highest priority is individual efforts and trial. Information technology will complement the lack of time. It is important to use information research technology to overcome real obstacles. Lasting EBP must use a number of web-based information research technologies to overcome the practical challenges encountered in EBP implementation.

• The Journal of the Korea Contents Association
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• v.11 no.8
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• pp.14-22
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• 2011

It is important for the strategy of service to provide the health information in the environment that the healthcare has been changed focusing on the preventive medicine. Recently, the various applications of u-healthcare have been presented by researchers. In this paper, we proposed the health information monitoring system using the context sensors based band. By wearing the proposed hand, the health status is gathered and vital signals are transmitted to the connected UMPC. It can be easily monitored according to the user locations in real time. To provide the health index according to the temperature, the air conditioning, the illumination, the humidity, and the ultraviolet rays, we use the various XML links extracted from RSS of the Korea Meteorological Administration. The health information is analyzed in terms of factors, such as, the asthma index, the stroke index, the skin disease index, the pulmonary disease index, the pollen concentration index, and the city high temperature index. Ultimately, this paper suggests empirical application to verify the adequacy and the validity with the proposed system. Accordingly, the satisfaction and the quality of services will be improved the healthcare.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.8
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• pp.1675-1686
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• 2011

We propose a spectrally efficient relaying scheme with multiple antennas for cellular networks which consist of base station (BS), relay station (RSs), and mobile stations (MSs). In general, a BS has more antennas than an RS or an MS. By using multiple antennas, a BS can support another MS with the same frequency resource, where an RS transmits data to a specific MS. In this case, the MS receiving data form an RS also receives the interference form the BS because the BS also uses the same frequency resource at the same time. In this paper, we propose ing and pre-whitening techniques as a pre-coding scheme at the BS for reducing the interference at the MS receiving data from the RS.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.42 no.5
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• pp.1102-1109
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• 2017

In Train Control Network(TCN), to support advanced services beyond control applications, it was revised to support high speed ethernet as IEC 61375-2-5(ETB) and IEC 61375-3-4(ECN). And Train Topology Discovery Protocol(TTDP) was included by which train-consist can be automatically configured. Meanwhile, to adopt wireless LAN as an next onboard network, TTDP need to be modified to reflect the characteristics of WLAN. This paper proposed a TTDP for WLAN using transmission power control and the number of HELLO-ACK handshake. And it determined whether the TTDP executed using the two WLAN interfaces having different bandwidths is correct or not. The proposed TTDP can allow to reduce interference from other nodes. For evaluation of performance of TTDP, NS-2 was used. The evaluation result shows the high reliability of the TTDP in wireless environment.