• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.11
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• pp.1463-1471
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• 2016

The indoor localization algorithm using the Difference Means based on Fingerprint (DMFPA) to improve the performance of indoor localization in moving Wi-Fi environment is proposed in this paper. In addition to this, the performance of the proposed algorithm is also compared with the Original Fingerprint Algorithm (OFPA) and the Gaussian Distribution Fingerprint Algorithm (GDFPA) by our developed indoor localization simulator. The performance metrics are defined as the accuracy of the average localization accuracy; the average/maximum cumulative distance of the occurred errors and the average measurement time in each reference point.

• Journal of IKEEE
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• v.22 no.3
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• pp.658-663
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• 2018

In this paper, we consider node deployment algorithms for the sequence-based localization (SBL) which is recently employed for in-door positioning systems, Whereas previous node selection or deployment algorithms seek to place nodes at centrold of the region where more targets are likely to be found, we observe that the boundaries dividing such regions can be good locations for the nodes in SBL systems. Motivated by this observation, we propose an efficient node deployment algorithm that determines the boundaries by using the well-known K-means algorithm and find the potential node locations based on the bi-section method for low-complexity design. We demonstrate through experiments that the proposed algorithm achieves significant localization performance over random node allocation with a substantially reduced complexity as compared with a full search.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.12A
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• pp.1836-1842
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• 2000

이 논문은 레일레이 감쇄 채널 환경에서 IMT-2000 파일럿 심볼 구조의 W-CDMA 시스템 역방향 링크의 채널 추정에 관한 LMS 적용형 알고리즘 성능을 WMSA(Weighted Multi-Slot Averaging)(K=1,2,3), 일정 추정이득 (Constant estimation gain) 및 RLS 알고리즘 성능과 비교 분석하였다. 이 논문의 모형은 IMT-2000 3GPP 규격의 W-CDMA 채널 구조, 변조 및 파일럿 패턴을 이용하였다. 파일럿 심볼 위치의 채널추정은 LMS 알고리즘을 이용하고 데이터 심볼 위치의 채널보상은 선형 보간으로 수행하였다. 저속 도플러 주파수에서는 WMSA(K=1,2,3) 성능이 일정 추정이득, RLS 및 LMS 적응형 알고리즘 성능보다 우수하며, WMSA(K=1) 성능의 경우 일정 추정이득, RLS 및 LMS 적응형 알고리듬 성능과는 큰 차이가 없다. 그리고 LMS 알고리즘 성능은 WMSA(K=1) 성능과 매우 비슷한 결과를 얻었다. 그러나 도플러 주파수가 고속화될수록 LMS 알고리즘의 성능이 WMSA(K=1), 일정 추정이득 및 RLS 알고리즘 성능보다 우수함을 확인하였다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.26 no.8B
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• pp.1141-1151
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• 2001

본 논문에서는 효과적으로 선택된 초기 탐색 위치를 이용한 움직임 추정의 고속 알고리즘을 제안하였다. 제안된 알고리즘에서는 2$\times$2화소 블록 평균으로 부표본화 영상에서 움직임 벡터를 얻어 원영상 비율로 확대하고, 주위 블록의 움직임으로부터 예측 움직임 벡터를 구하여, 이 중에서 정합오차가 작은 것을 초기 탐색 위치로 선택한다. 그리고 선택된 초기 탐색 위치를 중심으로 회전 탐색을 시작하여, 연속 소거 알고리즘으로 탐색할 후보 블록을 선택하고, 부분 정합 왜곡 소거법을 사용하여 블록간 정합오차 계산량을 줄이면서, 고속으로 움직임 벡터를 추정한다. 알고리즘의 실제 적용에 있어서는 선택된 초기 탐색 위치를 중심으로 회전 탐색 패턴의 탐색 범위를 조절하거나, 매크로 블록 당 복잡도를 제한하여 계산량을 줄일 수 있다. 실험 결과, 제안된 알고리즘은 전역탐색 블록정합 알고리즘에 대하여 0.2dB 이하의 미소한 평균 PSNR 저하만을 발생하면서, FBMA 복잡도의 3% 이하의 평균 복잡도를 소요하였다. 이것은 3단계 탐색법에 대하여 40% 이하의 계산량이다. 그리고 실험 영상들의 각 프레임에 대해서도 비슷한 성능을 보임을 확인하였다.

• Journal of Internet Computing and Services
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• v.12 no.2
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• pp.19-28
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• 2011

Recently, ubiquitous computing and related technologies is more and more growing concern about. Depending on the trend, the moving object recognition and tracking research have been required in order to meet the diverse needs of the user. In the location-based services, one of the most important issues in the indoor environment is to provide location-aware services. In this paper, the effective algorithm to help estimate the position of moving objects in an indoor environment is proposed. We propose an algorithm that combined the existing trilateration measurement and the improved measurement of environmental adaptation scene analysis. The proposed indoor location estimation algorithm use the trilateration measurement when we have enough anchor in the line-of-sight environment. Otherwise that use measurement of environmental adaptation scene analysis. Consequently, the proposed algorithm has been improved the localization accuracy of a moving object as well as was able to reduce complexity of the algorithm.

• Journal of Internet Computing and Services
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• v.11 no.2
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• pp.61-72
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• 2010

This paper addresses the problem of moving object localization using Ultra-Wide-Band(UWB) range measurement and the method of location accuracy improvement of the indoor moving object. Unlike outdoor environment, it is difficult to track moving object position due to various noises in indoor. UWB is a radio technology that has attention for localization applications recently. UWB's ranging technique offer the cm accuracy. Its capabilities for data transmission, range accurate estimation and material penetration are suitable technology for indoor positioning application. This paper propose a positioning algorithm of an moving object using UWB ranging technique and particle filter. Existing positioning algorithms eliminate estimation errors and bias after location estimation of mobile object. But in this paper, the proposed algorithm is that eliminate predictable UWB range distance error first and then estimate the moving object's position. This paper shows that the proposed positioning algorithm is more accurate than existing location algorithms through experiments. In this study, the position of moving object is estimated after the triangulation and eliminating the bias and the ranging error from estimation range between three fixed known anchors and a mobile object using UWB. Finally, a particle filter is used to improve on accuracy of mobile object positioning. The results of experiment show that the proposed localization scheme is more precise under the indoor.

• The Journal of the Korea institute of electronic communication sciences
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• v.6 no.5
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• pp.775-781
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• 2011

For the measurement of absolute position of mobile robot in indoor environments, the ultrasonic positioning systems using ultrasound have been researched for several years. Most of these ultrasonic positioning systems to avoid interference between the ultrasound are used for sequential transmitting. However, due to the use of sequential transmitting, the positions of transmitter to receive an ultrasound will change when the mobile robot moves. Therefore the accuracy of positioning is reduced. In this paper, the new position estimation algorithm with weighting factor according to the time of receipt is proposed. By applying the proposed algorithm to existing Ultrasonic Satellite System(USAT), the improved USAT is configured. The positioning performance of the improved USAT with the proposed position estimation algorithm are verified by experiments.

• Proceedings of the Acoustical Society of Korea Conference
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• 1998.06e
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• pp.185-188
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• 1998

본 연구에서는 256(16$\times$16)개의 마이크로폰 정방형 배열에 의한 음향 홀로그래피 시스템을 제작하고, FFT에 의한 음향 홀로그래피법 알고리즘을 이용한 음원 위치 추정에 관하여 기술한다. 본 연구에서 설계한 측정 시스템은 방사된 음들을 동시 수음함으로서 실시간 데이터 처리가 가능하다. 또한 환경 잡음이 존재하는 실음장에서도 계측시간을 단축함과 동시에 고분해능으로 안정하게 음원의 위치를 추정할 수 있다. 본 연구의 타당성을 검증하기 위해 SYSNOISE에 의한 음장해석과 음향 홀로그래피 알고리즘을 이용하여 마이크로폰 간격 및 측정면 크기, 측정거리의 최적 조건을 구한 후 실음장 측정 실험에 적용하였다. 수치 시뮬레이션과 무향실에서 실험 데이터에 의해 음원 위치를 추정한 결과 유사한 결과를 얻었다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.5
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• pp.1083-1094
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• 2012

Commercialized location estimation System with high accuracy is widely used for various services. However, if the systems aren't completely installed in an indoor, location estimation accuracy tend to be very poor. In this paper, indoor location estimation algorithm to improve the accuracy of object location, by correcting the location information obtained from a system that does not fully install, is proposed. In this paper, UWB-based Ubisense system that provides high position accuracy in an indoor environment was utilized. In conclusion, this paper was able to improve the positioning accuracy, by correcting that information about the location of the measured object in position estimation system.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.41 no.6
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• pp.47-53
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• 2004

This paper proposes an algerian for determining robot location using appearance-based paradigm. First, this algorithm compresses the image set using Principal Component Analysis(PCA) to obtain a low-dimensional subspace, called the eigenspace, and it makes a manifold that represent a continuous-appearance function. Neural network is employed to estimate the location of the mobile robot from the coefficients of the eigenspace. Then, Kalman filtering scheme is used for the fine estimation of the robot location. The algorithm has been implemented and tested on a mobile robot system. It is shown that the robot location is estimated accurately in several trials.