• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1606-1611
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• 2005

The goal of this paper is to develop a self localization of mobile robot using UHF RFID landmark. We present landmark, a location sensing archetype system that uses UHF Radio Frequency Identification (UHF RFID) technology for locating objects inside buildings. The major advantage of landmark is that it improves the overall accuracy of locating objects by utilizing the concept of reference tags. Based on experimental analysis, we demonstrate that passive UHF RFID is a viable and cost-effective candidate for indoor location sensing. We conduct a series of experiments to evaluate performance of the positioning of the landmark System. In the standard setup, we place RF Reader which has two antennas and 25 tags in our lab. This research uses the assumption-based coordinates (ABC) algorithm[3] for determining the localization of robot. Also, we show how Radio Frequency Identification (UHF RFID) can be used in robot-assisted indoor navigation for the visually impaired. The experiments illustrate that passive UHF RFID tags can act as reliable landmark that trigger local navigation behaviors to achieve global navigation objectives.

• Journal of the Korean Society for Nondestructive Testing
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• v.23 no.2
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• pp.140-147
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• 2003

A detection technique is studied to determine the location and the weight of an intruder into infrastructure using fiber optic ROTDR (Rayleigh optical time domain reflectometry) sensor. Fiber optic sensing plates buried in sand are prepared to measure the intruder effects. The signal of ROTDR was analyzed to confirm the detection performance. The constructed ROTDR system could be used up to 12km at the pulse width of 30ns. The location error was less than 3m and the weight could be detected into three levels of grade, such as 20kgf, 40kgf and 60kgf.

• Korean Journal of Remote Sensing
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• v.16 no.1
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• pp.99-108
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• 2000

The purpose of this paper is to combine digital elevation models (DEM) using SPOT satellite stereo images. After DEM extraction, a grid of longitude and latitude is generated using the results of DEM extraction. Heights at each grid location are determined from the obtained DEMs by using triangular image warping interpolation that uses the heights of the three nearest neighbors. The final heights at each grid location can then be determined by using the maximum likelihood as a fusion strategy. The input images used in this paper are two pairs of SPOT stereo images and experiments show that heights of DEM are successfully fused

• Korean Journal of Remote Sensing
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• v.10 no.2
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• pp.133-160
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• 1994

In this paper, we propose a comprehensive geometric correction algorithm of Along Track Scanning Radiometer(ATSR) images. The procedure consists of two cascaded modules; precorrection and fine co-location. The pre-correction algorithm is based on the navigation model which was derived in mathematical forms. This model was applied for correction raw(un-geolocated) ATSR images. The non-systematic geometric errors are also introduced as the limitation of the geometric correction by this analytical method. A fast and automatic algorithm is also presented in the paper for co-locating nadir and forward views of the ATSR images by using a binary cross-correlation matching technique. It removes small non-systematic errors which cannot be corrected by the analytic method. The proposed algorithm does not require any auxiliary informations, or a priori processing and avoiding the imperfect co-registratio problem observed with multiple channels. Coastlines in images are detected by a ragion segmentation and an automatic thresholding technique. The matching procedure is carried out with binaty coastline images (nadir and forward), and it gives comparable accuracy and faster processing than a patch based matching technique. This technique automatically reduces non-systematic errors between two views to .$\pm$ 1 pixel.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2003.10a
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• pp.219-224
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• 2003

Recently, the number of the use of Digital Photogrammetry is increasing, the Digital Photogrammetry is used for the acquisition of images, remote sensing and three dimension location. Especially, the three dimension location is more activated to use digital camera for the Digital Photogrammetry. The reason is that it is cheap and easy to use and also it has high confidence. Using non-metric digital camera not metric camera, in this research, to get images and apply the images to the Direct Liner Transformation which is one of the techniques in Digital Photogrammetry to get three dimensional location of a point. Ⅰ programmed the procedure with Visual C++ to get the position of points speedly and I tested possibility whether it can analyze the displacement and the existence of structure with measurement system which is structured by a inexpensive non-metric digital camera.

• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.608-611
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• 2005

The existing wired emergency call such as 119, 112 have its own location information to serving immediate rescue service. For the case of wireless emergency call by mobile phone, the location information should be provided by wireless network. This paper describes the network architecture and protocol for mobile emergency service referring TIAlEWJ-SID-036-A with reviews about technical issues, legacy factors and related researches. The mobile emergency service is divided into mobile emergency rescue service and mobile emergency alert service. The network reference model for mobile emergency rescue service is released in KOREA. In this paper, the interfaces between elements of the network reference model, and service scenarios, message flows are defined. Supplement to mobile emergency rescue service, the network reference model, interfaces and message flows for mobile emergency alert service are developed. The protocol is described by DID, and the proposed works are on processing for domestic standard of TTA.

• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.778-784
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• 2005

Miniaturization of computing devices, and advances in wireless communication and positioning systems will create a wide and increasing range of database applications such as location-based services, tracking and transportation systems that has to deal with Moving Objects. Various types of queries could be posted to moving objects, including past, present and future queries. The key problem is how to model the location of moving objects and enable Database Management System (DBMS) to predict the future location of a moving object. It is obvious that there is a need for an innovative, generic, conceptually clean and application-independent approach for spatio-temporal handling data. This paper presents behavioral aspect of the spatio-temporal databases for managing and querying moving objects. Our objective is to impelement and extend the Spatial TAU (STAU) system developed by Dr.Pelekis that provides spatio-temporal functionality to an Object-Relational Database Management System to support modeling and querying moving objecs. The results of the impelementation are demonstrated in this paper.

• Proceedings of the KSRS Conference
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• 2002.10a
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• pp.832-837
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• 2002

As diverse researches are working about location acquisition, storing method, data modeling and query processing of moving objects, the moving object database systems, which can gain, store and manage location information and query processing, are tuning up. As the mobile device is moving but have constraints, the convenience user interface for spatio-temporal query and viewing query result needs. In this paper, we designed user Interface for spatio-temporal query related moving objects, viewing query result, tracing current and past location of those and monitoring. And we designed system for implementation of these interfaces.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.715-717
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• 2003

Some previous works for nearest neighbor (NN) query processing technique can treat a case that query/data are both moving objects. However, they cannot find exact result owing to vagueness of criterion. In order to escape their limitations and get exact result, we propose new NN query techniques, exact CTNN (continuous trajectory NN) query, approximate CTNN query, and dynamic CTNN query. These are all superior to pervious works, by reducing of number of calculation, considering of trajectory information, and using of continuous query concept. Using these techniques, we can solve any situations and types of NN query in location-aware environment.

• Communications of the Korean Mathematical Society
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• v.16 no.3
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• pp.459-485
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• 2001

The aim of EIT (electrical impedance tomography) system is to image cross-section conductivity distribution of a human body by means of both generating and sensing electrodes attached on to the surface of the body, where currents are injected and voltages are measured. EIT has been suffered from the severe ill-posedness which is caused by the inherent low sensitivity of boundary measurements to any changes of internal tissue conductivity values. With a limited set of current-to-voltage data, figuring out full structure of the conductivity distribution could be extremely difficult at present time, so it could be worthwhile to extract some necessary partial information of the internal conductivity. We try to extract some key patterns of current-to-voltage data that furnish some core information on the conductivity distribution such s location and size. This overview provides our recent observation on the location search and the size estimation.