• International Journal of Fuzzy Logic and Intelligent Systems
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• v.6 no.2
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• pp.161-166
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• 2006

Localization of mobile agent within a sensing network is a fundamental requirement for many applications, using networked navigating systems such as the sonar-sensing system or the visual-sensing system. To fully utilize the strengths of both the sonar and visual sensing systems, This paper describes a networked sensor-based navigation method in an indoor environment for an autonomous mobile robot which can navigate and avoid obstacle. In this method, the self-localization of the robot is done with a model-based vision system using networked sensors, and nonstop navigation is realized by a Kalman filter-based STSF(Space and Time Sensor Fusion) method. Stationary obstacles and moving obstacles are avoided with networked sensor data such as CCD camera and sonar ring. We will report on experiments in a hallway using the Pioneer-DX robot. In addition to that, the localization has inevitable uncertainties in the features and in the robot position estimation. Kalman filter scheme is used for the estimation of the mobile robot localization. And Extensive experiments with a robot and a sensor network confirm the validity of the approach.

• Journal of the Korea Institute of Military Science and Technology
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• v.15 no.5
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• pp.557-564
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• 2012

This paper presents UGV localization using multi-sensor fusion based on federated filter in outdoor environments. The conventional GPS/INS integrated system does not guarantee the robustness of localization because GPS is vulnerable to external disturbances. In many environments, however, vision system is very efficient because there are many features compared to the open space and these features can provide much information for UGV localization. Thus, this paper uses the scene matching and pose estimation based vision navigation, magnetic compass and odometer to cope with the GPS-denied environments. NR-mode federated filter is used for system safety. The experiment results with a predefined path demonstrate enhancement of the robustness and accuracy of localization in outdoor environments.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.37 no.5
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• pp.331-341
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• 2019

With the popularity of sensor-rich environments, smartphones have become one of the major platforms for obtaining and sharing information. Since it is difficult to utilize GNSS (Global Navigation Satellite System) inside the area with many buildings, the localization of smartphone in this case is considered as a challenging task. To resolve problem of localization using smartphone a four step image-based localization method and procedure is proposed. To improve the localization accuracy of smartphone datasets, MMS (Mobile Mapping System) and Google Street View were utilized. In our approach first, the searching for candidate matching image is performed by the query image of smartphone's using GNSS observation. Second, the SURF (Speed-Up Robust Features) image matching between the smartphone image and reference dataset is done and the wrong matching points are eliminated. Third, the geometric transformation is performed using the matching points with 2D affine transformation. Finally, the smartphone location and attitude estimation are done by PnP (Perspective-n-Point) algorithm. The location of smartphone GNSS observation is improved from the original 10.204m to a mean error of 3.575m. The attitude estimation is lower than 25 degrees from the 92.4% of the adjsuted images with an average of 5.1973 degrees.

• Korean System Dynamics Review
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• v.7 no.2
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• pp.133-148
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• 2006

This study suggests a Causal Loop Diagram(CLD) of causality mechanism which are integrating matters of localization, networking, embeddedness & institutional thickness and collective learning. These five factors(localization, networking, embeddedness & institutional thickness, collective learning, innovative synergy) have been studied and proofed Also this study suggest a model of industry cluster based on holistic and global system thinking rather than local and linear thinking.

• Journal of Electrical Engineering and Technology
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• v.7 no.6
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• pp.1009-1013
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• 2012

A relationship between the sensor placement and the PDOP (Position Dilution of Precision) is derived in the TDOA-based localization system. And the geometric condition of the sensor placement is analyzed in order to get a minimum PDOP based on the derived relationship. Through computer simulations, effect of the sensor placement on the PDOP is observed.

• The Journal of Korea Robotics Society
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• v.7 no.1
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• pp.45-56
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• 2012

This paper proposes how to improve the performance of CSS-based indoor localization system. CSS based localization utilizes signal flight time between anchors and tag to estimate distance. From the distances, the 3-dimensional position is calculated through trilateration. However the error in distance caused from multi-path effect transfers to the position error especially in indoor environment. This paper handles a problem of reducing error in raw distance information. And, we propose the new localization method by pattern matching instead of the conventional localization method based on trilateration that is affected heavily on multi-path error. The pattern matching method estimates the position by using the fact that the measured data of near positions possesses a high similarity. In order to gain better performance of localization, we use EKF(Extended Kalman Filter) to fuse the result of CSS based localization and robot model.

• Journal of Agricultural Extension & Community Development
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• v.1 no.2
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• pp.105-121
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• 1994

This study examines the characteristics of agricultural extension in developed countries to provide the direction for the development of Korean agricultural extension system. The study, then, examines the validity for the localization of agricultural extension system. The study undertakes mil surveys of 314 persons in extension offices, administration offices, National Agricultural Cooperative Federation, agricultural school and colleges. The study justifies the localization of extension system in the long run but not in the short run. It finds the localization within next two years as suggested by central government is not appropriate and suggests the localization after the local government has settled down.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.247-248
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• 2006

In this paper, we propose a new sound localization algorithm for an active perception system. In an active perception system, an acquired sound is mixed with the sound of motors. So a sound localization algorithm for an active perception system requires a robustness for the noise and a computational efficiency. The proposed localization algorithm can achieve robustness and efficiency to use only sub-band channels that are contained harmonic structure of the target speech.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.42 no.2
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• pp.413-423
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• 2017

In this paper, we propose a ultrasonic and RF-based indoor localization system. In previous work, various systems were proposed for indoor localization, but they have limitation in applicability due to time-synchronization, complexity, or accuracy. To overcome such problems, an indoor localization system with ultrasonic and RF is proposed. A transmitting system is composed of a pair of ultrasonic and RF transmitters and the receiving system is composed of multiple ultrasonic receivers and one RF receiver. The theoretical performance limitation is also analyzed. To verify localization performance, we have implemented a receiving systems and a transmitting system using Arduino modules. Experiments were performed in $2m{\times}2m{\times}2m$ space and the localization errors had a mean of 6.1cm and a standard deviation of 1.6cm.

• The Journal of Korean Society for Radiation Therapy
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• v.12 no.1
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• pp.20-25
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• 2000

The accuracy of the target localization was evaluated by conventional and spiral CT in stereotactic radiosurgerv. Conventional and spiral CT images were obtained with geometrical phantom, which was designed to produce exact three-dimensional coordinates of several objects within 0.1mm error range. Geometrical phantom was attached by BRW headframe, intermediate head ring, and CT localizer. Twentv-seven slices of conventional CT image were scanned at 3 mm slice thickness. Spiral CT images were scanned at 3 mm slice thickness from the pitch value 1 to 3, and twenty-seven slices of image were obtained per each the pitch value. These CT images were transferred to a treatment planning system(X-knife, Radionics) by ethernet, Three-dimensional coordinates of these images measured from the treatment planning system were compared to known values of geometrical phantom. The mean localization error of the target localization of conventional CT was 1.4mm. In case of spiral CT, the error of the target localization was within 1.6mm from the pitch value 1 to 1.3, but was more than 30mm above the pitch value 1.5. In conclusion, as the localization error of spiral CT was increased in high pitch value compared to conventional CT, the application of spiral CT will be with caution in stereotactic radiosurgery.