• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.399-401
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• 2003

This paper presents a geostatistical contextual classifier for the classification of remote sensing data. To obtain accurate spatial/contextual information, a simple indicator kriging algorithm with local means that allows one to estimate the probability of occurrence of certain classes on the basis of surrounding pixel information is applied. To illustrate the proposed scheme, supervised classification of multi-sensor remote sensing data is carried out. Analysis of the results indicates that the proposed method improved the classification accuracy, compared to the method based on the spectral information only.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.256-261
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• 2005

In this research, we propose a path-planning algorithm for an autonomous mobile robot using geographical information, under the condition that the robot moves in unknown environment. All image inputted by camera at every sampling time are analyzed and geographical elements are recognized, and the geographical information is embedded in environmental map. The geographical information was transformed into 1-dimensional evaluation value that expressed the difficulty of movement for the robot. The robot goes toward the goal searching for path that minimizes the evaluation value at every sampling time. Then, the path is updated by integrating the exploited information and the prediction on unexploited environment. We used a sensor fusion method for improving the mobile robot dead reckoning accuracy. The experiment results that confirm the effectiveness of the proposed algorithm on the robot's reaching the goal successfully using geographical information are presented.

• Journal of Advanced Marine Engineering and Technology
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• v.29 no.5
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• pp.560-570
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• 2005

In this paper, we discuss the tracking system for a wheelchair which can follow the path of a human target such as a nurse in hospital. The problem of human tracking is that it requires recognition of feature as well as the tracking of human positions. For this purpose the use of a high cost visual sensor such as laser finder or streo camera makes the tracking a high cost additional expense. This paper proposes the tracking system uses a low cost infrared range-finder and CCD camera, The Infrared range-finder and CCD camera can create a target candidate through each target recognition algorithm. and this information is fused in order to reduce the uncertainties of a target decision and correct the positional error of the human. The effectiveness of the proposed system is verified through experiments.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.49 no.3
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• pp.1-11
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• 2012

Data association plays an important role in intelligent systems. This paper presents the Bayesian formulation of data association and its applications to intelligent systems. We first describe the Bayesian formulation of data association developed for solving multi-target tracking problems in a cluttered environment. Then we review applications of data association in intelligent systems, including surveillance using wireless sensor networks, identity management for air traffic control, camera network localization, and multi-sensor fusion.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.48 no.6
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• pp.1-7
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• 2011

The depth camera measures range information of the scene in real time using Time-of-Flight (TOF) technology. Measured depth data is then regularized and provided as a depth image. This depth image is utilized with the stereo or multi-view image to generate high-resolution depth map of the scene. However, it is required to correct noise and distortion of TOF depth image due to the technical limitation of the TOF depth camera. The corrected depth image is combined with the color image in various methods, and then we obtain the high-resolution depth of the scene. In this paper, we introduce the principal and various techniques of sensor fusion for high-quality depth generation that uses multiple camera with depth cameras.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.41 no.3
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• pp.93-100
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• 2004

This paper presents a method to integrate the multiple impressions of a finger for improving fingerprint verification performance. Small-sized sensor has advantage that it can be used in many application fields. However, sufficiently large impression of fingerprint is not available due to the small sensing area, and this degrades the verification performance of the system. The proposed method overcomes this problem by combining the information of fingerprints for enrollment. To combine the fingerprints, the alignment process is important first of all. In the proposed algorithm multiple impressions of a finger are coarsely aligned using the corresponding minutiae pairs and then are finely aligned using the Distance Map. We construct an integrated template for enrollment in aligned coordinate system Since this integrated template represents the enlarged finger region, the problem that is occurred by using small sensor can be overcome. Experimental results show that the use of the integrated template of multiple impressions improves the performance of the fingerprint verification system.

• Journal of the Korea Society of Computer and Information
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• v.27 no.2
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• pp.9-14
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• 2022

In this study, we propose a method for moving a device such as a flexible air sculpture while stably maintaining the user's desired posture. To accomplish this, a robot system with a structure of a mobile robot capable of running according to a given trajectory was studied by applying the PI algorithm and horizontal maintenance posture control using IMU. The air sculptures used in this study often use thin strings in a fixed posture. Another method is to put a load on the center of gravity to maintain the posture, and it is a system with flexibility because it uses air pressure. It is expected that these structures can achieve various results by combining flexible structures and mobile robots through the convergence process of digital sensor technology. In this study, posture control was performed by fusion of the driving technology of AGV(Automatic Guided Vehicle),, a field of robot, and technologies applying various sensors. For verification, the given performance evaluation was performed through an accredited certification test, and its validity was verified through an experiment.

• Journal of Advanced Navigation Technology
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• v.21 no.3
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• pp.251-257
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• 2017

Recently, hybrid positioning system combining GPS, vision sensor, and inertial sensor has drawn many attentions to estimate accurate vehicle positions. Since accurate multi-sensor fusion requires efficient time synchronization, this paper proposes an efficient method to obtain time synchronized measurements of vision sensor, inertial sensor, and OBD device based on GPS time information. In the proposed method, the time and position information is obtained by the GPS receiver, the attitude information is obtained by the inertial sensor, and the speed information is obtained by the OBD device. The obtained time, position, speed, and attitude information is converted to the color information. The color information is inserted to several corner pixels of the corresponding image frame. An experiment was performed with real measurements to evaluate the feasibility of the proposed method.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.34S no.3
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• pp.33-45
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• 1997

In this paper, we propsoe a new method of th ecommunication system for cooperative behaviors and works in collective autonomous mobile robots. A communication function among the collective robots is essential to intelligent cooperative works. In genral, global communication is effective for small number of robots. However when the number of robot goes on increasing, this becomes difficult to be realized because of limited communication capacity and increasing amount of information to handle. And also the problems such as communciation interfeence and improper message transmission occur. So we propose local communication system based on infrared sensor to realize the cooperative behavior among robots as the solution of above problem. It is possible to prevent overflow of information and exchange of complex information by fusion sign board model which transmits the information to unspecified robots and message passing model which communicate a specific robot. And we formularize optimal communication range by analysis of information propagation mechanism from the proposed comunication system. At last we verify the effectiveness of the proposed communication system from example of cooperative works.

• International Journal of Internet, Broadcasting and Communication
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• v.11 no.1
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• pp.27-38
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• 2019

Sensors collect information for Internet of Things (IoT)-based services. However, indoor construction sites have a poor communication environment and many interfering elements that make it difficult to collect sensor information. In this study, a network was constructed between a Bluetooth Low Energy (BLE)-based IoT device based on a serverless IoT framework and a router. This experimental environment was applied to large- and small-scale indoor construction sites. Experiments were performed to test the communication performance of BLE-based IoT devices and routers at indoor construction sites. An analysis of the received signal strength indication (RSSI) graph patterns collected from the communication between the BLE-based IoT devices and routers for different testbed site situation revealed areas with good communication performance and poor communication performance due to interfering factors. The results confirmed that structural components of the building as well as the materials, equipment, and temporary facilities used in indoor construction interfere with the communication performance. Construction project managers will require improved technical knowledge of IoT, such as optimizing the router placement and matching communication between the router and workers, to improve the communication performance for large-scale indoor construction.