• Journal of Korea Society of Industrial Information Systems
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• v.16 no.2
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• pp.65-72
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• 2011

In this paper, a real-time monocular vision based navigation system is developed for the disabled people, where online background learning and vector field histogram are used for identifying obstacles and recognizing avoidable paths. The proposed system is performed by three steps: obstacle classification, occupancy grid map generation and VFH-based path recommendation. Firstly, the obstacles are discriminated from images by subtracting with background model which is learned in real time. Thereafter, based on the classification results, an occupancy map sized at $32{\times}24$ is produced, each cell of which represents its own risk by 10 gray levels. Finally, the polar histogram is drawn from the occupancy map, then the sectors corresponding to the valley are chosen as safe paths. To assess the effectiveness of the proposed system, it was tested with a variety of obstacles at indoors and outdoors, then it showed the a'ccuracy of 88%. Moreover, it showed the superior performance when comparing with sensor based navigation systems, which proved the feasibility of the proposed system in using assistive devices of disabled people.

• Journal of the Korean Orthopaedic Association
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• v.53 no.6
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• pp.478-489
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• 2018

Total knee arthroplasty has become a standard procedure for advanced knee arthritis to relieve pain and improve function. Computer-assisted navigation systems have been used in total knee arthroplasty to improve the mechanical axis of the limb as well as the alignment and position of the components. A computer-assisted navigation system has the advantage of real-time feedback during surgery, such as mediolateral balance in extension and flexion gap, alignment of the lower limb, and components. On the other hand, the computer-assisted navigation system requires an additional stab wound for tracker fixation, which can increase the likelihood of superficial wound infection and stress fractures and increase the operation time and cost of surgery. The clinical efficacy of computer-assisted navigation in total knee arthroplasty is also controversial. Compared to the conventional technique, computer navigation improves the accuracy of the postoperative mechanical axis within outliers of $3^{\circ}$ varus or $3^{\circ}$ valgus. This paper reviews the surgical technique, pitfalls, clinical and radiological outcomes, useful clinical cases, and future perspectives in computer-assisted navigation total knee arthroplasty.

• 한국IT서비스학회:학술대회논문집
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• 2006.11a
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• pp.491-497
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• 2006

최근 유비쿼터스를 비롯한 정보기술의 급격한 발전에 따라 GIS를 통하여 누구나 일상 속에서 직접 지리정보를 활용할 수 있게 되면서 공공분야 및 연관 산업분야에 큰 파급효과를 가져오고 있다. 특히, 지리정보의 유통 방식이 기존의 공급자가 제공하는 지리정보에 대해 조회 위주에서 벗어나 현장에서 실시간으로 지리정보를 가공하고 직접 갱신할 수 있는 양방향 서비스로 진화하면서, GIS는 u-City 구현에 필수적인 위치기반 공공서비스 인프라 구현을 통해 민간의 내비게이션, 텔레매틱스 등 관련분야 시장규모가 해마다 급속히 성장하고 있다. 하지만 이러한 상승세에도 불구하고 여전히 기관마다 서로 유사한 서비스를 제공하는 경우가 빈번하고, 민간의 대다수 유관업체들 역시 아직 지속적인 수익모델을 찾지 못해 단말기 제조 등 특정 분야에만 머무르고 있는 실정이다. 따라서 업종특성에 맞는 보다 구체적이고 유망한 신규 사업모델의 개발이 시급하다. 본 연구는 GIS 특성에 근거하여 사업모델 개발에 필요한 성공요인을 도출하고 그 타당성을 분석함으로서, 이를 통해 다양한 성공적인 지리정보 활용 비즈니스 모델의 구현과 평가에 기여하고자 한다.

• Korean Journal of Remote Sensing
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• v.29 no.2
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• pp.183-195
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• 2013

Real-time high-precision image georeferencing is important for the realization of image based precise navigation or sophisticated augmented reality. In general, high-precision image georeferencing can be achieved using the conventional simultaneous bundle adjustment algorithm, which can be performed only as post-processing due to its processing time. The recently proposed sequential bundle adjustment algorithm can rapidly produce the results of the similar accuracy and thus opens a possibility of real-time processing. However, since the processing time still increases linearly according to the number of images, if the number of images are too large, its real-time processing is not guaranteed. Based on this algorithm, we propose a modified fast algorithm, the processing time of which is maintained within a limit regardless of the number of images. Since the proposed algorithm considers only the existing images of high correlation with the newly acquired image, it can not only maintain the processing time but also produce accurate results. We applied the proposed algorithm to the images acquired with 1Hz. It is found that the processing time is about 0.02 seconds at the acquisition time of each image in average and the accuracy is about ${\pm}5$ cm on the ground point coordinates in comparison with the results of the conventional simultaneous bundle adjustment algorithm. If this algorithm is converged with a fast image matching algorithm of high reliability, it enables high precision real-time georeferencing of the moving images acquired from a smartphone or UAV by complementing the performance of position and attitude sensors mounted together.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.3
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• pp.590-598
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• 2016

It comes into the spotlight as the new Blue Ocean in which the connected car industry in which the car and mobile communication technology is convergence. All sorts of infortainments services connecting with the portable electronic device(Smart phone, tablet PC, and MP3 player) and car are rapidly grown. The Connected car emphasizes the vehicle connectivity with the concept that the car has communication with the around on a real time basis and it provides the safety and expedience to the operator and using the thing of Internet (IoT) in the car and supports the application, presently, the entertainment service including the real-time Navigation, parking assistant function, not only the remote vehicle control and management service but also Email, multimedia streaming service, SNS and with the platform. Intelligent vehicle network is studied as the kind according to MANET(Mobile Ad Hoc Network) for the safety operation of the cars of the road and improving the efficiency of the driving.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.211-215
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• 2015

It comes into the spotlight as the new Blue Ocean in which the connected car industry in which the car and mobile communication technology is convergence. All sorts of infortainments services connecting with the portable electronic device(Smart phone, tablet PC, and MP3 player) and car are rapidly grown. The Connected car emphasizes the vehicle connectivity with the concept that the car has communication with the around on a real time basis and it provides the safety and expedience to the operator and using the thing of Internet (IoT) in the car and supports the application, presently, the entertainment service including the real-time Navigation, parking assistant function, not only the remote vehicle control and management service but also Email, multimedia streaming service, SNS and with the platform. Intelligent vehicle network is studied as the kind according to MANET(Mobile Ad Hoc Network) for the safety operation of the cars of the road and improving the efficiency of the driving. The intelligent vehicle network is comprised for the driving information offering changing rapidly of the communication(V2V: Vehicle to Vehicle) between the car and the car, communication(V2I : Vehicle to Infrastructure) between the infrastructure and the car, and V2X (Vehicle to Nomadic).

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.6
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• pp.1337-1342
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• 2014

Increasingly important user based service on the smart media era, and increasing awareness about the user experience. In this study, by considering these realities, what impact location based constructs on smartphone environment, continuous intention to use you want to identification. Thus, this study conducted of preference the influencing factors for location based constructs. First steps, based constructs known empirical studies were categorized information, entertainment, safe&emergency, navigation&tracking and advertising& commerce. Second Steps, the categorized factors were analyzed preference relationship between constructs using AHP(analytic hierarchy process) technique. Questionnaire survey was conducted to those who employees S Telecom in Busan city and Gyeongnam province during 2000. 4. 15 and 2014. 4. 30. The result of the analysis might be summarized that the navigation(0.133) has the highest preference ran in the constructs. Based on these findings, several theoretical and practical implications were suggested and discussed.

• Journal of Navigation and Port Research
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• v.38 no.5
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• pp.457-462
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• 2014

Indoor-positioning systems are useful to various applications. Navigation system is one of the most popular applications, which needs the information of directions of nodes' movements. Specifically the applications should get the information in real-time to properly show the current moving position of a node. In this paper, simple vector-based algorithms are proposed to compute amount and direction of changes of azimuth of mobile nodes' heading directions using existing indoor positioning systems in indoor environments where azimuth sensors do not work properly. Previous algorithms calculate the azimuth changes by too many steps of topology-based formula. The algorithms proposed in this paper get the amount of changes of azimuth by simple formula based on vector, and determine the direction of changes by the sign of value of simple formula based on the previous movement of nodes. The algorithms are much simpler and less error-prone than previous ones, and then they can detect changes in many location-based applications as well. The performance of the algorithms is proved logically and mathematically.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.05a
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• pp.171-174
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• 2014

Increasingly important user based service on the smart media era, and increasing awareness about the user experience. In this study, by considering these realities, what impact location based constructs on smartphone environment, continuous intention to use you want to identification. Thus, this study conducted of preference the influencing factors for location based constructs. First steps, based constructs known empirical studies were categorized information, entertainment, safe&emergency, navigation&tracking and advertising& commerce. Second Steps, the categorized factors were analyzed preference relationship between constructs using AHP(analytic hierarchy process) technique. Questionnaire survey was conducted to those who employees S Telecom in Busan city and Gyeongnam province during 2000. 4. 15 and 2014. 4. 30. The result of the analysis might be summarized that the navigation(0.133) has the highest preference ran in the constructs. Based on these findings, several theoretical and practical implications were suggested and discussed.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.33 no.4
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• pp.287-296
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• 2015

Recent navigation systems provide quick guide services, based on processing real-time traffic information and past traffic information by applying predictable pattern for traffic information. However, the current pattern for traffic information predicts traffic information by processing past information that it presents an inaccuracy problem in particular circumstances(accidents and weather). So, this study presented a more precise predictive traffic information system than historical traffic data first by analyzing route search data which the drivers ask in real time for the quickest way then by grasping traffic congestion levels of the route in which future drivers are supposed to locate. First results of this study, the congested route from Yang Jae to Mapo, the analysis result shows that the accuracy of the weighted value of speed of existing commonly congested road registered an error rate of 3km/h to 18km/h, however, after applying the real predictive traffic information of this study the error rate registered only 1km/h to 5km/h. Second, in terms of quality of route as compared to the existing route which allowed for an earlier arrival to the destination up to a maximum of 9 minutes and an average of up to 3 minutes that the reliability of predictable results has been secured. Third, new method allows for the prediction of congested levels and deduces results of route searches that avoid possibly congested routes and to reflect accurate real-time data in comparison with existing route searches. Therefore, this study enabled not only the predictable gathering of information regarding traffic density through route searches, but it also made real-time quick route searches based on this mechanism that convinced that this new method will contribute to diffusing future traffic flow.