• 한국군사과학기술학회지
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• 제13권4호
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• pp.551-560
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• 2010

In this paper, we suggest a localization method of factors affecting the accuracy of Air-to-Ground weapon delivery. The proposed method, called FBEL(Factor-Based Error Localization), is based on the fault localization technique widely utilized in the realm of software engineering field. FBEL localizes the major factors affecting the performance of weapon delivery. To analyze the effectiveness and the applicability of FBEL, we applied FBEL to real firing data and got the major factors caused the errors. We expect that the method could contribute to improve the quality of weapon delivery system. We also expect that it may aid improvement of pilot capability greatly, if it is applied to pilot firing training.

• Journal of Positioning, Navigation, and Timing
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• 제5권1호
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• pp.1-9
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• 2016

Range-based wireless localization system must measure accurate range between a mobile node (MN) and reference nodes. However, non-line-of-sight (NLOS) error caused by the spatial structures disturbs the localization system obtaining the accurate range measurements. Localization methods using the range measurements including NLOS error yield large localization error. But filter-based localization methods can provide comparatively accurate location solution. Motivated by the accuracy of the filter-based localization method, a filter residual-based NLOS error estimation method is presented in this paper. Range measurement-based residual contains NLOS error. By considering this factor with NLOS error properties, NLOS error is mitigated. Also a process noise covariance matrix tuning method is presented to reduce the time-delay estimation error caused by the single dynamic model-based filter when the speed or moving direction of a MN changes, that is the used dynamic model is not fit the current dynamic of a MN. The presented methods are evaluated by simulation allowing direct comparison between different localization methods. The simulation results show that the presented filter is more accurate than the iterative least squares- and extended Kalman filter-based localization methods.

• 한국시뮬레이션학회논문지
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• 제20권3호
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• pp.59-67
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• 2011

본 논문에서는 오류 검출을 위해 소프트웨어 오류 추정 기법을 활용하여 항공무장 시스템인 공대지 사격의 오류 요인을 분석하기 위한 모델을 제시하고 모델을 기반으로 오류 요인 영향을 분석하였다. 선행 연구에서는 공대지 무기체계의 정확도에 영향을 미치는 오류 요소를 분석하고 결함위치추정 기법인 FBEL(Factor-based Error Localization) 기법을 제안하였으며 실사격 자료에 적용하여 오류 요소를 분석하였다. 그러나 다양한 요인 중 하나의 요인인 정확도를 고정하여 적용하므로 다양한 사격 정확도 변화에 따른 사격 오류 발생 요소와의 상관관계는 밝히지 못하였다. 본 연구에서는 사격 오류 요소의 상관관계 분석을 통하여 보다 세밀한 오류 분석 모델을 제시하고 시간과 비용이 제한적이거나 테스트 케이스가 적은 상태에서 오류 발생 가능 요소를 추정하는 방법을 제안한다. 제안된 방법은 실사격 자료를 이용한 시뮬레이션을 통해 그 효용성을 입증하였으며, 무기체계 공대지 시험평가에서 어떤 요소들이 정확도에 영향을 미치는 지를 분석하는데 성공적으로 활용될 수 있음을 보였다.

• 대한전자공학회논문지TC
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• 제44권12호
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• pp.44-53
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• 2007

이 논문은 실외에서 실시간 적이고 안정적이며 정확도가 높은 위치 인식 정보 및 위치 기반 서비스 제공을 위한 복합 위치인식 알고리즘 개발에 초점을 둔다. 현재 사용 중인 위성 항법 시스템에 갈릴레오 위성 항법 시스템을 병행하여 사용할 경우 사용 주파수의 증가와 가시 위성의 증가로 전리층 오차 등 여러 가지 오차 요인을 줄일 수 있다. 따라서 더 이상 거리 오차는 위치 인식에서는 문제가 되지 않는다. 하지만 노이즈로인해 생기는 chips 등기 오차는 acquisition이나 tracking 지연 오차를 유발하게 되어 수신기의 성능을 저하시킨다. 이를 해결하기 위하여 이 논문에서는 고 정밀도 향상을 위한 correlator를 제안하여 수신기의 성능 향상에 그 목적이 있다.

• ETRI Journal
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• 제38권4호
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• pp.735-745
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• 2016

The Paris agreement at the 21st Conference of the Parties (COP21) emphasizes the reduction of greenhouse gas emissions and increase in energy consumption in all areas. Thus, an important aspect is energy saving in buildings where the lighting is a major component of the electrical energy consumption. This paper proposes a building energy management system employing visible light communication (VLC) based on LED lighting. The proposed management system has key characteristics including personalization and localization by utilizing such VLC advantages as secure communication through light and location-information transmission. Considering the efficient implementation of an energy-consumption adjustment using LED luminaires, this paper adopts variable pulse position modulation (VPPM) as a VLC modulation scheme with simple controllability of the dimming level that is capable of providing a full dimming range. This paper analyzes the VPPM performances according to variable dimming for several schemes, and proposes a VPPM demodulation architecture based on dimming-factor acquisition, which can obtain an improved performance compared to a 2PPM-based scheme. In addition, the effect of a dimming-factor acquisition error is analyzed, and a frame format for minimizing this error effect is proposed.

• International Journal of Internet, Broadcasting and Communication
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• 제11권3호
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• pp.106-110
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• 2019

The interaural level difference (ILD) used for the sound localization using stereo signals is to find the difference in energy that the sound source reaches both ears. The conventional ILD does not consider the time difference of the stereo signals, which is a factor of lowering the accuracy. In this paper, we propose a synchronized ILD that obtains the ILD after synchronizing these time differences. This method uses the cross-correlation function (CCF) to calculate the time difference to reach both ears and use it to obtain synchronized ILD. In order to prove the performance of the proposed method, we conducted two sound localization experiments. In each experiment, the synchronized ILD and CCF or only the synchronized ILD were given as inputs of the deep neural networks (DNN), respectively. In this paper, we evaluate the performance of sound localization with mean error and accuracy of sound localization. Experimental results show that the proposed method has better performance than the conventional methods.

• 전자공학회논문지CI
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• 제47권4호
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• pp.109-117
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• 2010

HSDPA, WiBro, 모바일 디바이스 등의 정보통신 기술의 발전으로 사용자가 컴퓨터나 네트워크를 의식하지 않고 언제 어디서나 네트워크에 접속할 수 있는 유비쿼터스 컴퓨팅 환경의 구현이 가능해졌다. 이러한 유비쿼터스 컴퓨팅 환경에서 사용자의 위치에 따른 특정 정보를 제공하는 위치 기반 서비스(Location Based Service, LBS)의 중요성이 대두되고 있다. 본 논문에서는 관성 측정 장치(Inertial Measurement Unit, IMU)의 오차 보정을 위한 필터 및 알고리즘을 소개하고 실내 측위 보정을 위한 매핑 알고리즘을 제안한다. 제안하는 매핑 알고리즘은 지도를 자동으로 인식하여 교차로, 복도, 목적지로 분류하고 현재 위치를 인식하여 잘못된 매핑이 일어나지 않게 하고 사용자의 움직임 이벤트 발생 시 위치 검색의 효율을 높인다. 또한 유동적인 매핑계수를 두어 이동거리와 방향에 대한 오차 보정을 지속적으로 수행한다.

• 제어로봇시스템학회논문지
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• 제20권10호
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• pp.1044-1050
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• 2014

Robots used for pipe inspection have been studied for a long time and many mobile mechanisms have been proposed to achieve inspection tasks within pipelines. Localization is an important factor for an inpipe robot to perform successful autonomous operation. However, sensors such as GPS and beacons cannot be used because of the unique characteristics of inpipe conditions. In this paper, an inpipe localization algorithm based on elbow detection is presented. By processing the projected marker images of laser pointers and the attitude and heading data from an IMU, the odometer module of the robot determines whether the robot is within a straight pipe or an elbow and minimizes the integration error in the orientation. In addition, an off-line positioning algorithm has been performed with forward and backward estimation and Procrustes analysis. The experimental environment has consisted of several straight pipes and elbows, and a map of the pipeline has been constructed as the result.

• 대한임베디드공학회논문지
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• 제6권2호
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• pp.108-116
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• 2011

Non-line-of-sight (NLOS) error is the most common and also a major source of errors in wireless location system. A novel weighting factor (NWF) method is presented in this paper, based on the RSS(Received Signal Strength) measurements, path loss model and Circular Disk of Scatterers Model (CDSM). The proposed positioning method effectively weighted the TOA distance measurements for each Base Station (BS). Simulation results show that the proposed method efficiently weighted the distance measurements and achieve higher localization accuracy than that of Linear Line of Position (LLOP) and Believable Factor Algorithm (BFA).

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제16권9호
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• pp.3194-3210
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• 2022

Wall obstruction is the main factor leading to the non-line of sight (NLoS) error of indoor localization based on received signal strength indicator (RSSI). Modeling and correcting the path loss of the signals through the wall will improve the accuracy of RSSI localization. Based on electromagnetic wave propagation theory, the reflection and transmission process of wireless signals propagation through the wall is analyzed. The path loss of signals through wall is deduced based on power loss and RSSI definition, and the theoretical model of path loss of signals through wall is proposed. In view of electromagnetic characteristic parameters of the theoretical model usually cannot be accurately obtained, the statistical model of NLoS error caused by the signals through the wall is presented based on the log-distance path loss model to solve the parameters. Combining the statistical model and theoretical model, a hybrid model of path loss of signals through wall is proposed. Based on the empirical values of electromagnetic characteristic parameters of the concrete wall, the effect of each electromagnetic characteristic parameters on path loss is analyzed, and the theoretical model of regional path loss of signals through the wall is established. The statistical model and hybrid model of regional path loss of signals through wall are established by RSSI observation experiments, respectively. The hybrid model can solve the problem of path loss when the material of wall is unknown. The results show that the hybrid model can better express the actual trend of the regional path loss and maintain the pass loss continuity of adjacent areas. The validity of the hybrid model is verified by inverse computation of the RSSI of the extended region, and the calculated RSSI is basically consistent with the measured RSSI. The hybrid model can be used to forecast regional path loss of signals through the wall.