• Journal of Sensor Science and Technology
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• v.28 no.6
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• pp.385-389
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• 2019

As we become an aging society, the number of dementia patients increases every year (an estimated 10% of the elderly, equating to 1.27 million in 30 years). In addition, 17,000 cases of missing people with disabilities and dementia are reported annually, indicating that more than one person per hour goes missing. More than 50% of those who are lost suffer injuries (some of which are fatal) within 24 hours after going missing. This is why measures are urgently required to ensure safety of the elderly. The core function of the disappearances prevention system proposed by this research group is to identify and respond early to deviations of dementia patients from their homes or facilities by identifying the location of the occurrence of disappearance, so that real-time notifications occur when a they leave the protected area. In addition, multiple receivers and public transportation integrated terminals share information when a patient leaves and uses public transportation to ensure their safe return. Most existing beacon-based positioning service models have fixed signal transmitters and are serviced in the form of transport receivers, but the proposed service model has users wearing the BLE beacon and receivers fixed.

• Proceedings of the Korea Contents Association Conference
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• 2007.11a
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• pp.30-34
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• 2007

Surveyors has desired eagerly surveying technology and equipments which are able to acquire a lot of data easily, quickly and precisely. Laser has the merits that is able to obtain a large number of measurements with high precision in a short time and one of concrete realizations is a terrestrial laser scanner called Terrestrial LiDAR. This paper describes 3D modelling of a old architecture which was conducted using a Z-F laser system and the result of positioning analysis. Use of terrestrial laser scanner is much more efficient than existing photogrammetry in measuring and database constructing for preservation and restoration of cultural assets as well as for deformation monitoring and safety diagnosis of structures.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.5
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• pp.566-572
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• 2014

Recently, indoor navigation has been applied in large convention centers by using wireless sensor networks (WSNs), which provide not only a user's path to be traveled but also orientation and shopping information to increase user's convenience. This paper presents the localization system for estimating relative coordinates without pre-deployment of the reference node based on ultra wide band (UWB) ranging system, which is relatively suitable for indoor localization compared to other wireless communications, and azimuth sensor. The proposed localization system which consists of an azimuth sensor and a mobile node composed of three nodes estimates relative coordinates of the reference node without applying any recursive and time consumption algorithms. Also, in the process of estimating relative coordinates of the reference node, ranging errors are minimized through the proposed technique and the number of nodes can be reduced. Experimental results show the feasibility and validity of the proposed system.

• Journal of Korea Society of Digital Industry and Information Management
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• v.13 no.3
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• pp.65-73
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• 2017

The fifth generation(5G) of wireless networks will connect not only smart phone but also unimaginable things. Therefore, 5G cellular network is facing the soaring traffic demand of numerous user devices. To solve this problem, a huge amount of 5G base stations will need to be installed. The base station positioning problem is an NP-hard problem that does not know how long it will take to solve the problem. Because, it can not find an answer other than to check the number of all cases. In this paper, to solve the NP hard problem, we compare the tabu search and the genetic algorithm using real maps for optimal cell planning. We also perform Monte Carlo simulations to study the performance of the Tabu search and Genetic algorithm for 5G cell planning. As a results, Tabu search required 2.95 times less computation time than Genetic algorithm and showed accuracy difference of 2dBm.

• Journal of the Society of Naval Architects of Korea
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• v.53 no.5
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• pp.428-434
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• 2016

A lot of drawings for pipe construction and installation are needed to construct plant process system on the offshore plant structures. Depending on their scale or complexity, the required number of drawings related pipes sometimes amounts to several hundreds of thousands. Most major shipyards, therefore, have their own system which can automatically depict pipes’ geometric, manufacturing, and BOM(Bill of Material) information on the drawings. However, as the complexity and absolute quantity in the isometric region on the drawings is increased, the information extraction from the customized DB and positioning at the typical locations does not get to be enough to avoid the overlap between geometric contours, labels, and symbols. For this reason, the novel methods to arrange additional annotations without overlaps are presented in the paper. This approach is expected to increase the readability and legibility of the drawing and prevent the human error, and finally decrease the time-consuming and tedious jobs which are unnecessarily required to designers.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.12 no.4
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• pp.494-502
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• 2001

GPS(Global Positioning System) and GLONASS(GLObal Navigation Satellite System) are basic technologies providing the information of the position and the time, and they have various applications such as navigation, survey, control, and so on. However, each GPS and GLONASS has limited number of visible satellites, and, from the view of strategy, it is undesirable to be heavily dependent on only one system. Thus, GPS/GLONASS combined receiver became required to obtain more precise navigation and system stability. In this paper, the RF front end of GPS/GLONASS combined receiver was fabricated on 130$\times$80 $\textrm{mm}^2$ PCB(Printed Circuit Board), and its system application was shown finally one chip possibility of GLONASS receiver is studied.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.18 no.2
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• pp.101-110
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• 2000

This study focuses on examination of the availability and effectiveness about application of the differential GPS methods for navigation and acquisition of the geo-spatial information. For this, the algorithms related to a navigation solution and differential GPS were implemented in MATLAB code, a number of software simulations on test model were carried out to assess its performance, comparing the results with those obtained from the commercial software. Expecially, the results coming from tracking test on test model of the OO's WADGPS which is the commercial real-time satellite-based augmentation system via geostationary satellite (GEOs), which has been investigated with those from the above GPS methods. And also, the accuracy of absolute positioning by Navigation solution and WADGPS before and after SA-off has been compared. The above results show that DGPS methods are very reliable and efficient methods for acquisition of the geo-spatial information.

• Journal of Astronomy and Space Sciences
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• v.19 no.4
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• pp.367-376
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• 2002

As of September 2002, there are more than 60 operational permanent Global Positioning System (GPS) stations in South Korea. Their data are being used for a variety of purposes: geodynamics, geodesy, real-time navigation, atmospheric science, and geography. Especially, many of the sites are reference stations for DGPS (Differential GPS). However, there has been no comprehensive and qualitative analysis published to evaluate the data quality. In this study, we present preliminary results of our assessment of the permanent GPS sites in South Korea. We have analyzed the multi-path characteristics of each station using a quality-checking software package called TEQC. Another multipath analysis tool based on post-fit phase residuals was used to check the repeating patterns and the amount of the multipath at each site. The long-term stability of each station was analyzed using the root-mean-square (RMS) error of the estimated site positions for one year, which enabled us to evaluate the mount stability. In addition, the number of cycle slips at each site was derived by TEQC. Based on these series of tests, we compared the stability and data quality of permanent GPS stations in South Korea.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.340-342
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• 2003

Location based services based on positions of moving objects are expanding the business area gradually. The location is included all estimate position of the future as well as the position of the present and the past. Location based routing service is active business application in which the position information of moving objects is applied efficiently. This service includes the trajectory of past positions, the real-time tracing of present position of special moving objects, and the shortest and optimized paths combined with map information. In this paper, we describes the location based routing services is extend in distributed web GIS environment. Web GIS service systems provide the various GIS services of analyzing and displaying the spatial data with friendly user - interface. That is, we propose the efficient architecture and technologies for servicing the location based routing services in distributed web GIS environment. The position of moving objects is acquired by GPS (Global Positioning System) and converted the coordinate of real world by map matching with geometric information. We suppose the swapping method between main memory and storages to access the quite a number of moving objects. And, the result of location based routing services is wrapped the web-styled data format. We design the schema based on the GML. We design these services as components were developed in object-oriented computing environment, and provide the interoperability, language-independent, easy developing environment as well as re - usability.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.6 no.4
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• pp.361-366
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• 2005

With quantitative and qualitative growth of libraries, number of books and patrons of the library are increasing rapidly. However, the growth brings up many new challenges to the library management process. One of the noticeable challenges is to ease the process of locating books users want. The purpose of this research is to develop a positioning system that can help library users locate books without going through tedious shelf searching process. The R-LIM system we propose can be used for such Purpose. It is based on the RFID technology, and consists of tags, readers, antennas, wireless terminals and light-emitting diodes. With the system, one may not only locate books easily, but also may put the book back to appropriate shelves promptly. Since R-LIM can do library inventory in real-time, it can be used fer anti-thief purposes as well.