• Journal of the Society of Disaster Information
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• v.19 no.1
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• pp.10-17
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• 2023

Purpose: In this paper, a distance estimation technique for indoor location estimation using IR-UWB is proposed and researched. We propose an algorithm that can increase the SNR lowered due to clutter or noise in an indoor environment. Method: In order to clutter suppression and detect weak signals, we analyze the existing studies of background remover, correlation, and singular vector decomposition techniques and propose an algorithm. Result: The proposed algorithm, the average error was 0.57m up to 11.5m, and the error were 0.49m from 6m to 11.5m. the average error rate was reduced by about 1m compared to the previous study. Conclusion: It can be used as a technique for detecting weak signals in clutter and noise environments for distance or location estimation, and can also be used as a human life detection technique to reduce damage to people in a disaster situation by using UWB radar which has highly transparent.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.3
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• pp.551-560
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• 2011

Recently, There has been increasing concern about WLAN-based indoor positioning system. Most of the existing WLAN-based positioning systems use a fingerprinting method as a main approach. In the fingerprinting approach, the accuracy of the location of a mobile objects is proportional to the number of reference points. However, depending on the increasing number of reference points in the training phase, it requires more time and effort to create fingerprint database. To solve these problems, we propose the new indoor positioning algorithm that calculate the distance between a mobile objects and an AP using the information of surrounding environment WLAN based APs and applied the particle filter to the proposed algorithm in order to improve the accuracy of the estimated location in this paper. To implement this algorithm, at first environmental information database such as wall, iron door, glass door, partition etc. existing in the periphery of the AP should be established. The positioning use attenuation model and path loss model. Our experimental results with proposed algorithm are verified that the positioning accuracy was low but solved the problems with fingerprinting, compared with other positioning algorithms.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.75-76
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• 2015

본 논문은 실내 이동로봇의 자율주행 방법을 적용한 결과를 기술한다. 구체적으로는 경로 계획, 장애물 회피, 위치 추정에 대해서 설명한다. 위의 기능들은 작성된 지도 정보와 Encoder, IMU, 초음파센서, 비콘 등 여러 센서 데이터를 토대로 구현되었다. 경로계획에는 A* 알고리즘을 활용하여 최단거리 경로를 구했으며, 장애물 회피에는 초음파센서를 활용한 자체 알고리즘을 적용하였다. 또한 비콘을 활용한 삼변 측량법을 활용하여 위치 추정을 하였다. 이러한 방법들을 통합하여 실내 네비게이션 방법을 실제로 구현하여 실험하였으며, 실험을 통하여, 제안한 방법이 로봇을 안전하게 자율주행하게 함을 확인하였다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.8
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• pp.643-650
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• 2014

Recently, the wireless communication applications are studied in various environment by the development of short range communication system like wireless sensor networks. This paper presents the analysis of localization schemes for ship application using received signal strength. The localization schemes using received signal strength from wireless networks are classified under two methods, which are Range based method and Range free method. Range based methods estimate the location with least square estimation based on estimated distance using path-loss model. Range free methods estimated the location with the information of anchor nodes linked to target. Simulation results show the appropriate localization scheme for each cabin environments based on the empirical path-loss model in warship's internal space.

• Journal of Digital Convergence
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• v.11 no.4
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• pp.243-249
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• 2013

In this paper, GPS(Global Positioning System) that can be used outdoors and GPS(Global Positioning System) is not available for indoor Wi-Fi(Wireless Fidelity) using the Android-based location information system has been designed and implemented. Pedestrians in a room in order to estimate the location of the pedestrian's position, regardless of need to obtain the absolute position and relative position, depending on the movement of pedestrians in a row it is necessary to estimate. In order to estimate the initial position of the pedestrian Wi-Fi Fingerprinting was used. Most existing Wi-Fi Fingerprinting position error small WKNN(Weighted K Nearest Neighbor) algorithm shortcoming EWKNN (Enhanced Weighted K Nearest Neighbor) using the algorithm raised the accuracy of the position. And in order to estimate the relative position of the pedestrian, the smart phone is mounted on the IMUInertial Measurement Unit) because the use did not require additional equipment.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.10
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• pp.2530-2536
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• 2014

Many studies have been made on location estimation under indoor environments which GPS signals do not reach, and, as a result, a variety of estimation methods have been proposed. In this paper, we deeply consider a problem of location estimation in a ship with a multi-story structure, and investigate a location estimation method using the fingerprint scheme based on the K-Nearest Neighbor algorithm. A reliable DB is constructed by measuring 100 received signals at each of 39 RPs in order to employ the fingerprint scheme, and, based on the DB, a simulation to estimate the location of a randomly-positioned terminal is performed. The simulation result confirms that the performance of location estimation by the fingerprint scheme is quite satisfactory.

• Journal of Advanced Navigation Technology
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• v.19 no.6
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• pp.564-573
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• 2015

GPS is the representative positioning technology for providing the location information. This technique has the disadvantage that does not operate in the shadow areas, such as urban or dense forest and the interior. This paper proposes a hybrid indoor positioning algorithm, which estimates a more accurate location of the terminal using strength of the Wi-Fi signal from the indoor AP. To determine the location of the user, we establish the most appropriate path loss model for the measurement environment. by using the RSSI value measured in a variety of environment such as building structure, person, distance, etc. The path loss exponent obtained by the path loss model is changed according to the environment. REKF, PF estimate the position of the terminal by using measured value from the AP with path loss exponent. For more accurate position estimation, we select positioning system by the value of threshold measured by experiments rather than a single positioning system. Experimental results using the proposed hybrid algorithm show that the performance is improved by about 17% than the conventional single positioning method.

• Proceedings of the KIEE Conference
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• 2008.10b
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• pp.85-86
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• 2008

로봇은 오도메터리 정보를 이용해 위치추정을 할 수 있다. 그러나 주행하는 동안 발생되는 슬립현상에 의해 오도메터러 정보만으로는 로봇의 정확한 위치추정을 할 수 없다. 정확한 위치추정을 위해서 관성센서를 이용하여 오도메터리 정보를 보정한 위치추정 방법이 있다. 실내 이동로봇에 적용하려면 관성센서는 소형이어야 하는데, 그에 따라 노이즈는 심해지고, 정확성도 낮아지는 문제가 있나. 그래서 현재까지는 이런 문제를 갖고 있는 관성센서를 실내 이동로봇의 위치추정의 정확성을 높이기 위해 비관성센서 또는 카메라 영상을 조합하는 연구들을 하고 있다. 그러나 이러한 연구들은 대부분 관성센서 성능 실험과 시뮬레이션에 결론을 내리고 있어 실제 실험에 따른 정확성을 확인할 수 없다. 또한 최근 영상 SIFT 알고리즘을 적용한 SLAM 연구에서도 나타나는 문제는 이동로봇의 위치추정의 부정확성이다. 따라서 본 논문은 SLAM에서 문제가 되는 위치추정의 부정확성을 최소화하기 위해 자이로와 가속도계를 이용하여 정학한 위치추정을 하고자 한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2019.10a
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• pp.668-670
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• 2019

본 논문은 로봇의 위치추정에 관한 연구로서, 기존의 실내 자율주행은 탐색되지 않은 영역에서의 위치추정이 어렵다는 것을 보완하기 위해 Graph based SLAM 알고리즘을 이용하는 자율주행 로봇에 Beacon을 적용함으로써 보다 정확한 위치추정 능력을 향상하는 방법을 제시한다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.8
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• pp.1779-1788
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• 2012

Recently, demands of application services in consideration of interior environment according to the stream of times, Ubiquitous. In case of interior location-based service, WLAN is now mostly used. But it is largely affected by environmental changes. To solve this problem, lots of studies on UWB are underway. The reason why studies on UWB are much made lies in that it is not much affected by environment changes owing to radio wave characteristics. So this study suggests the location correction algorithm which derives values with less influence of environment and high accuracy and corrects with more accurate location information using Ubisense system based on UWB technologies. The location correction algorithm suggested is one made after constructing environment database and use it to estimate more accurate location from the location measuring system in a high position.