• 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.

• Journal of the Korea Computer Industry Society
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• v.3 no.5
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• pp.547-556
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• 2002

This paper was proposed a wave path loss prediction algorithm using multilayer perceptron (MLP) model and wave propagation characteristic parameters for Wireless LAN in indoor radio environments. Receiving power was predicted by calculating indoor path loss in a Wireless LAN that has transmission power of 100mW and frequency of 2.4GHz, and was compared with measured. In the result of measurement shows that there is a difference between predicted and measured receiving power which can be reduced by an accurate analysis of the various path loss factors. In order to fix the access point(AP) positions was used the proposed a wave path loss prediction algorithm, and designed the optimum cell for Wireless LAN.

• KIISE Transactions on Computing Practices
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• v.23 no.4
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• pp.210-216
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• 2017

In the paper we propose and implement a new indoor localization system where the techniques of magnetic field based fingerprinting and pedestrian dead reckoning are combined. First, we determine a target's location by comparing acquired magnetic field values with a magnetic field map containing pre-collected field values at different locations and choosing the location having the closest value. As the target moves, we use pedestrian dead reckoning to estimate the expected moving path, reducing the maximum positioning error of the initial location. The system eliminates the problem of localization error accumulation in pedestrian dead reckoning with the help of the fingerprinting and does not require Wi-Fi AP infrastructure, enabling cost-effective localization solution.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.8 no.4
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• pp.9-14
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• 2008

Ubiquitous implementation of indoor location-based technology is recognized that one of the important elements of the technology. Specifically, the hospital management of patients, the silver-town management, the implementation of the smart home for the indoors rather than outdoors in a range of broadband users for location-aware technology is needed. This paper in wireless devices with an indoor location awareness shows about the system's technical design and implementation. Location-based technology for wireless LAN users aware of the strength of radio signals (Received Signal Strength Indication, RSSI) using trilateration. Topographic mapping system will be implemented wireless devices and servers, Access Point (AP), which is the system's development and testing throughout the physical environment to determine the potential for real-life applications.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.12
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• pp.107-116
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• 2013

We proposed the WSN monitoring system applied the augmented reality to visualize effectively an indoor WSN. To implement system, we used wireless sensor network, indoor location determination, location-based augmented reality technology. First, we composed the wireless sensor networks indoors and implement web server and then get data from server DB using Android phones. Then, we obtained the (x, y) coordinates using the triangulation method from RSSI of three point of the strongest signal strength of the AP's. Also, we adjusted coordinates using the Kalman filter. Finally, we inserted the adjusted coordinates to the latitude and the longitude of the Mixare that use the GPS signal, and we got location of user and wireless sensor in the server DB. After that, we implemented augmented reality system using the android phone and wireless sensor location and data and real life image.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.10a
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• pp.75-76
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• 2022

WPS is a system that finds the location of a current moving object through information of a wireless AP. The current location is determined by utilizing the outdoor and indoor AP signal strength characteristics. Even if the map is configured for the first service, the map information of the DB built by the variability of the AP signal cannot be 100% reliable in the case of outdoor. Therefore, various algorithms are needed to increase the accuracy of WPS. This paper proposes a system to increase positioning accuracy by applying various methods to determine the current position of a moving object.

• Proceedings of the Korean Information Science Society Conference
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• 2011.06a
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• pp.241-242
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• 2011

실내에서 보행자의 움직임을 추적하기 위해 AP를 이용한 WiFi 핑거프린팅, 별도의 센서를 이용하는 방법 등 다양한 방법이 연구되고 있다. 본 논문은 보행자의 움직임을 추적하여 스마트 폰의 지자계 센서를 이용해 코너를 찾아 건물의 실내 레이아웃을 추측하기 위한 방법을 제시하고 그 성능을 분석한다.

• Journal of Institute of Control, Robotics and Systems
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• v.19 no.2
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• pp.146-151
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• 2013

With the development of mobile internet, requirements of positioning accuracy for the LBS (Location Based Service) are becoming more and more higher. The LBS is based on the position of each mobile device. So, it requires a proper acquisition of accurate user's indoor position. Thus indoor positioning technology and its accuracy is crucial for various LBS. In general, RSSI (Received Signal Strength Indicator) measurements are used to obtain the position information of mobile unit under WLAN environment. However, indoor positioning error increases as multiple AP's configurations are becoming more complex. To overcome this problem, an enhanced indoor localization method by AP (Access Point) selection criteria adopting DOP (Dilution of Precision) is proposed.

• Proceedings of the Korea Information Processing Society Conference
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• 2016.10a
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• pp.775-778
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• 2016

로봇 주행 기술은 전통적인 로봇요소 기술 외에도 여러 기술로 대상 응용서비스에 따라 IT 기술과 적극적인 융합을 통해 다양한 주행방법과 주행성능이 향상되고 있다. 본 논문에서는 대표적인 실내 모바일 로봇인 로봇 청소기를 대상으로 기존의 방법인 적외선과 카메라 방법이 아닌 보통 가정에도 쉽게 존재하는 AP를 이용해 목표를 설정하여 포섭구조 이론을 기반으로 동적인 환경에서도 충전 스테이션 까지 자율 주행이 가능한 로봇 알고리즘을 설계하였다. 그 결과 동적인 환경을 설정하여 로봇이 AP를 찾아가는 것을 확인하였고 주행 경로와 경과 시간을 표로 도출하여 다른 경우를 예측할 수 있게 하였다. 향후 행동 기반 로봇과 다양한 센서를 이용하여 로봇의 위치와 목표점 사이의 최단거리 경로를 구하여 주행하는 것이 목표이다.

• Electronics and Telecommunications Trends
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• v.29 no.6
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• pp.113-125
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• 2014

최근 모바일 단말 기술의 발전과 무선망의 성능 향상에 따른 다양한 서비스가 제공되고 있는 추세이며, 위치정보인식시스템과 결합된 서비스에 많은 관심이 높아졌다. 본고에서는 GPS(Global Positioning System)의 신호가 미치지 못하는 건물의 실내환경에 적합한 경로 안내서비스 및 지하시설물 안내 등 초정밀 실내 측위 서비스를 제공하기 위한 융합 측위 방안을 제안한다. 융합 측위 방안은 실내외 연속 측위를 위해 실외에서는 GPS를 이용하고 실내환경에서는 WLAN 기반의 측위 전용 AP(Access Point)를 이용, 전파신호의 LoS(Line of Sight)를 확보하여 측위하고 전파음영지역에서는 스마트폰의 가속도, 자이로센서 등 여러 가지 관성센서를 활용하여 PDR(Pedestrian Dead Reckoning) 알고리즘 등을 적용하여 측위한다. 또한 측위 정확도 향상 및 오차를 줄이기 위한 방법으로 LSE(Least Squire Estimation) 및 EKF(Extended Kalman Filter), KNN(K-Neighbor Node)/MSSM(Maximum Signal Strength Model) Algorithm 등 다양한 융합 측위 알고리즘을 적용하여 실내환경에 적합한 최적의 초정밀 실내 측위 서비스를 제공한다.