• 한국정보통신학회논문지
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• 제16권5호
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• pp.1083-1094
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• 2012

현재 상용화 되어 있는 위치 추정 시스템은 높은 정확도로 다양한 서비스에 폭넓게 사용되고 있다. 그러나 위치추정 시스템은 실내에서 완벽하게 설치하지 않을 경우 위치 추정 정확도가 매우 좋지 않은 경향을 보인다. 본 논문에서는 Location Fingerprint 기법을 활용하여 완벽하게 설치되지 않은 위치 추정 시스템으로부터 얻은 위치 정보를 보정하여 객체의 위치 정확도를 향상시켜 설치비용을 최소화할 수 있는 실내 위치 추정 알고리즘을 제안한다. 본 논문에서는 실내 환경에서 우수한 위치 정밀도를 제공하는 UWB 기반의 Ubisense 시스템을 활용하였다. 결론적으로, 본 논문에서는 위치 추정 시스템에서 측정한 객체의 위치 정보를 보정함으로써 위치 정확도를 향상시킬 수 있었다.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2016년도 춘계학술대회
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• pp.575-576
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• 2016

최근 GPS(Global Positioning System) 기술들을 활용하여 정확도를 향상시키기 위한 연구가 진행되고 있다. 그러나 위성신호를 수신 받을 때 문제가 발생할 경우 정확도가 현저히 떨어지는 문제점이 있다. 본 논문에서는 정확도 향상을 위해 GPS 기술과 지정된 위치에 대한 정보를 제공하는 GIS(Geographic Information System) 기술을 융합하는 시스템을 설계한다. 지정된 위치 정보와 사용자의 위치 정보를 비교하여 해당 위치에 대한 사용자의 진입여부를 판별한다. 이에 따라 GIS 기술을 활용하여 지정된 위치 정보를 사용자가 제공받으면 위성신호 수신에 방해가 있는 경우에도 위치 정보의 정확도가 향상될 수 있을 것으로 사료된다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제3권1호
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• pp.119-133
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• 2009

The purpose of this research is to accurately estimate the location of a device using the received signal strength indicator (RSSI) of IEEE 802.11 WLAN for location tracking in indoor environments. For the location estimation method, we adopted the calibration model. By applying the Adaptive Zone Based K-NNSS (AZ-NNSS) algorithm, which considers the velocity of devices, this paper presents a 9% improvement of accuracy compared to the existing K-NNSS-based research, with 37% of the K-NNSS computation load. The accuracy is further enhanced by using a Kalman filter; the improvement was about 24%. This research also shows the level of accuracy that can be achieved by replacing a subset of the calibration data with values computed by a numerical equation, and suggests a reasonable number of calibration points. In addition, we use both the mean error distance (MED) and hit ratio to evaluate the accuracy of location estimation, while avoiding a biased comparison.

• Journal of Communications and Networks
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• 제15권1호
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• pp.54-60
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• 2013

In this paper, a novel method called location-based delivery (LBD), which combines the short message service (SMS) and global position system (GPS), is proposed, and further, a realistic system for tracking a target's movement is developed. LBD reduces the number of short message transmissions while maintaining the location tracking accuracy within the acceptable range. The proposed approach, LBD, consists of three primary features: Short message format, location prediction, and dynamic threshold. The defined short message format is proprietary. Location prediction is performed by using the current location, moving speed, and bearing of the target to predict its next location. When the distance between the predicted location and the actual location exceeds a certain threshold, the target transmits a short message to the tracker to update its current location. The threshold is dynamically adjusted to maintain the location tracking accuracy and the number of short messages on the basis of the moving speed of the target. The experimental results show that LBD, indeed, outperforms other methods because it satisfactorily maintains the location tracking accuracy with relatively fewer messages.

• 항공우주기술
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• 제1권2호
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• pp.141-148
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• 2002

본 연구는 KOMPSAT-1 EOC 영상의 기하정확도를 향상시키고자 수행되었다. 많은 EOC 영상의 지상위치오차를 분석하였고, 그 오차가 시스템내의 시간 부정확성과 자세데이터의 오차로 인한 것임을 알 수 있었다. 그 개선방안으로 Ancillary 데이터의 시간데이터와 자세데이터를 재구성하였고, 이를 적용하여 영상처리한 결과에서 EOC 영상데이터의 기하정확도가 향상되는 것을 확인하였다.

• 제어로봇시스템학회논문지
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• 제16권12호
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• pp.1159-1166
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• 2010

Today, detecting the location of moving object has been traced as various methods in our world. In this paper, we preset the system to improve the estimation accuracy utilizing detail localization using radar sensor based on WSN and situational awareness for a calibration (context aware) database, Rail concept. A variety of existing location tracking method has a problem with receiving of data and accuracy as tracking methodology, and since these located data are the only data to be collected for location tracing, the context aware or monitering as the surrounding environment is limited. So, in this paper, we enhanced the distance aware accuracy using radar sensor utilizing the Doppler effect among the distance measuring method, estimated the location using the Triangulation algorithm. Also, since we composed the environment data(temperature, illuminancem, humidity, noise) to entry of the database, it can be utilized in location-based service according to the later action information inference and positive context decision. In order to verify the validity of the suggested method, we give a few random situation and built test bed of designed node, and over the various test we proved the utilizing the context information through route tracking of moving and data processing.

• 대한임베디드공학회논문지
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• 제7권2호
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• pp.85-93
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• 2012

In this paper, we proposed Wireless LAN (WLAN) localization method that enhances database construction based on weighting factor and analyse the characteristic of the WLAN received signals. The weighting factor plays a key role as it determines the importance of Received Signal Strength Indication (RSSI) value from number of received signals (frequency). The fingerprint method is the most widely used method in WLAN-based positioning methods because it has high location accuracy compare to other indoor positioning methods. The fingerprint method has different location accuracies which depend on training phase and positioning phase. In training phase, intensity of RSSI is measured under the various. Conventional systems adapt average of RSSI samples in a database construction, which is not quite accurate due to variety of RSSI samples. In this paper, we analyse WLAN RSSI characteristic from anechoic chamber test, and analyze the causes of various distributions of RSSI and its influence on location accuracy in indoor environments. In addition, we proposed enhanced weighting factor algorithm for accurate database construction and compare location accuracy of proposed algorithm with conventional algorithm by computer simulations and tests.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권2호
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• pp.1162-1179
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• 2017

In this paper, we propose indoor location tracking method using RSSI(Received Signal Strength Indicator) value received from BLE(Bluetooth Low Energy) beacon. Due to the influence of various external environmental factors, it is very difficult to improve the accuracy in indoor location tracking. In order to solve this problem, we propose a novel method of reducing the noise generated in the external environment by using a double Gaussian filter. In addition, the value of the RSSI signal generated in the BLE beacon is different for each device. In this study, we propose a method to allocate additional weights in order to compensate the intensity of signal generated in each device. This makes it possible to improve the accuracy of indoor location tracking using beacons. The experiment results show that the proposed method effectively decrease the RSSI deviation and increase location accuracy. In order to verify the usefulness of this study, we compared the Kalman filter algorithm which is widely used in signal processing. We further performed additional experiments for application area for indoor location service and find that the proposed scheme is useful for BLE-based indoor location service.

• Nuclear Engineering and Technology
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• 제56권5호
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• pp.1733-1737
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• 2024

In order to specify the location of the scintillation pixel that interacted with gamma rays in the positron emission tomography (PET) detector, conventionally, after acquiring a flood image, the location of interaction between the scintillation pixel and gamma ray could be specified through a pixel-segmentation process. In this study, the experimentally acquired signal was specified as the location of the scintillation pixel directly, without any conversion process, through the simulation data and the deep learning algorithm. To evaluate the accuracy of the specification of the scintillation pixel location through deep learning, a comparative analysis with experimental data through pixel segmentation was performed. In the same way as in the experiment, a detector was configured on the simulation, a model was built using the acquired data through deep learning, and the location was specified by applying the experimental data to the built model. Accuracy was calculated through comparative analysis between the specified location and the location obtained through the segmentation process. As a result, it showed excellent accuracy of about 85 %. When this method is applied to a PET detector, the position of the scintillation pixel of the detector can be specified simply and conveniently, without additional work.

• 한국측량학회:학술대회논문집
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• 한국측량학회 2006년도 춘계학술발표회 논문집
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• pp.111-118
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• 2006

The LBS (Location Based Service) location information is the element which is important decides the application of form service, Recently the location accuracy with the method which applies the wireless Internet DGPS improved inside 1 meter Like this. application of the LBS which corresponds In the location accuracy which Improves accurate the Location Information output system development which is accurate stands is essential. In this study which it sees it used 1:5000 digital map MS visual 6.0 Active X controls of the country geography intelligence Personnel and it developed the location information output module of web browser base. The location information output system which is developed it will be able to secure the convenient characteristic of precision and visual program of the digital map simultaneously and the maximum anger of LBS application is expected.