• Journal of the Institute of Electronics Engineers of Korea CI
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• v.45 no.4
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• pp.64-72
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• 2008

Researchers nowadays are trying to implement u-Healthcare (ubiquitous Healthcare) systems for real-time monitoring and analysis of patients' status through a low-cost and low-power wireless sensor network. u-Healthcare system has an aim to provide reliable and fast medical services for patients regardless of time and space by transmitting to doctors a large quantity of vital signs collected from sensor networks. Existing u-Healthcare systems can merely monitor patients' health status. However, it is not easy to derive physiologically meaningful results by analyzing rapidly vital signs through the existing u-Healthcare systems. We introduce a Grid computing technology for deriving the results by analyzing rapidly the vital signs collected from the sensor network. Since both sensor network and Grid computing use different protocols, a gateway is needed. In addition, we also need to construct a gateway which includes the functions such as an efficient management and control of the sensor network, real-time monitoring of the vital signs and communication services related to the Grid network for providing u-Healthcare services effectively. In this paper, to build an advanced u-Healthcare system by using these two technologies most efficiently, we design and present the results to implement a SensorGrid gateway which connects transparently the sensor network and the grid network.

• Spatial Information Research
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• v.23 no.4
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• pp.57-66
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• 2015

At these day, owing to functional limitations and cost issues, used image map in web service have a problem which can not make exactly meet the user needs. This study aims to create an individual map for user suitable purposes using HTML5 technology that implement the vector map creation and its functions with services. The results of this study, the invisible problems of the tilting and rotation functions in image-based map utilizing the existing web environment were solved in HTML5 vector map. And to access the map information, by implementing the function of expressing the background and name data to selectively derive, various results were expressed in the map. Also, as a result of a comparison of performance the time required was measured at 0.88sec which comes in the range of the first loading time between 0.78sec and 7.56sec in a commercial map service, which showed the possibility of its commercialization. compared to 180GB of image maps for the production of a national map index system, the volume to produce a vector map was 2.5GB, a decrease by over 90%, which solved the issue of costs for a storage space. As a result, this study of HTML5 vector map design and implementation presented a plan for providing information suitable for the requirements of the users who use spatial information through utilizing a variety of information and expanding functions.

• Journal of the Economic Geographical Society of Korea
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• v.13 no.3
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• pp.398-415
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• 2010

The purpose of this paper is to grasp levels of cost burden in pollution treatment by measuring efficiencies and shadow prices by pollutants in Korean cities. The efficiencies and shadow prices of pollutants will be compared for cities divided by Seoul metropolitan area and non-Seoul metropolitan area. Annual shadow prices of NOx, SOx, and PM10 emissions in the cities of Seoul metropolitan area are 0.846, 0.318, 0.816, respectively for 1999-2005. The annual shadow prices in the cities of Non-Seoul metropolitan area are 0.848, 0.272, and 0.789, respectively over the same periods. The shadow prices of SOx showed similar levels between two areas but those of NOx and PM10 of cities in Seoul metropolitan area were higher. NOx emission quantities of both areas have similar increasing patterns because the NOx has mainly increased with augmentation of transportation regardless of Seoul metropolitan and non-Seoul metropolitan areas. It seems that the reason the shadow prices of two pollutants for the cities of Seoul metropolitan area are higher, is because environmental regulation is stronger in the cities of Seoul metropolitan area, the cities of Seoul metropolitan relatively show higher quantities of pollution reduction under given desirable outputs, and generally have industrial sectors with small pollution emission. In the future we need to reduce pollutants in the various respects such as adjustment of overall industry structure, energy consumption pattern, and reviews of arrangement of living space for the cities located on the downward-sloping segment of production frontier.

• Journal of IKEEE
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• v.11 no.4
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• pp.348-357
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• 2007

Due to the improved performance and cost of personal mobile devices and rapid progress of wireless communication technology, the number of users who utilize these devices is increasing. This trend requires various types of services be available to users. So far, there have been many solutions provided for the shortest path problem. But, technologies which can offer various recommendation services to user depending on user’s current location are focused on Euclidean spaces rather than road network. Thus, in this paper, we extend the previous work to satisfy this requirement on road network database. Our proposed scheme requires pre-computation for the efficient query processing. In the preprocessing step, we first partition the input road network into a fixed number of Voronoi polygons and then pre-compute routing information for each polygon. In the meantime, we select the number of Voronoi polygons in proposition to the scale of road network. Through this selection, the required size of pre-computation is linearly increasing to the size of road network. Using this pre-computated information, we can process queries more quickly. Through experiments, we have shown that our proposed scheme can achieve excellent performance in terms of scheduling time and the number of visited nodes.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.46 no.4
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• pp.28-38
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• 2009

In this study, a remote air quality monitoring system for underground spaces was developed by using NDIR-based CO$_2$ sensor. And the remote monitoring system based on wireless sensor networks was installed practically on the subway station platform. More than 6.5 million citizens commutate everyday by the Seoul subway transportation that is the most typical public transportation. They concern about air quality with increasing interest on public health or many workers in subway stations or underground shopping centers. Recently, the Korean Ministry of Environment has operated the air quality monitoring system in some subway stations for testing phase. However, it showed many defects which are large-scale, high-cost and maintenance of precision sensors imported from abroad. Therefore this research includes the reliability test and a theoretical study about the inexpensive commercialized CO$_2$ sensor for reliable measurement of air quality which changes rapidly by the surrounding environments. And then we develop the wireless sensor nodes and the gateway applied for remote air quality monitoring. In addition, web server program was realized to manage air quality in the subway platform. This result will be valuable for a basic research for air quality management in underground spaces for future study.

• Journal of Korea Spatial Information System Society
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• v.8 no.3
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• pp.105-115
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• 2006

A sensor network which uses DCS(Data-Centric Storage) stores the same data into the same sensor node. Thus it has a hot spot problem when the sensor network grows and the same data arise frequently. In the past researches of the sensor network using DCS, the hot spot problem caused by growing the sensor network was ignored because they only concentrated on managing stored sensor data efficiently. In this paper, we proposed a non-equal region split method that supports efficient scalability on storing multi-dimensional sensor data. This method can reduce the storing cost, as the sensor network is growing, by dividing whole space into regions which have the same number of sensor nodes according to the distribution of sensor nodes, and storing and managing sensor data within each region. Moreover, this method can distribute the energy consumption of sensor nodes by increasing the number of regions according to the size of the sensor network, the number of sensor nodes within the sensor network, and the quantity of sensor data. Therefore it can help to increase the life time and the scalability of the sensor network.

• Science of Emotion and Sensibility
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• v.23 no.1
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• pp.29-40
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• 2020

Visually impaired people use tactile maps to get spatial information about their surrounding environment, find their way, and improve their independent mobility. However, classical tactile maps that make use of braille to describe the location within the map have several limitations, such as the lack of information due to constraints on space and limited feedback possibilities. This study describes the development of a new multi-modal interactive tactile map interface that addresses the challenges of tactile maps to improve the usability and independence of visually impaired people when using tactile maps. This interface adds touch gesture recognition to the surface of tactile maps and enables the users to verbally interact with a voice agent to receive feedback and information about navigation routes and points of interest. A low-cost prototype was developed to conduct usability tests that evaluated the interface through a survey and interview given to blind participants after using the prototype. The test results show that this interactive tactile map prototype provides improved usability for people over traditional tactile maps that use braille only. Participants reported that it was easier to find the starting point and points of interest they wished to navigate to with the prototype. Also, it improved self-reported independence and confidence compared with traditional tactile maps. Future work includes further development of the mobility solution based on the feedback received and an extensive quantitative study.

• Tunnel and Underground Space
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• v.17 no.5
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• pp.389-410
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• 2007

For moderately jointed to massive rock masses, the failure and deformation behaviors around an excavated opening are absolutely influenced by the initial rock stress and strength of in-situ rock mass. The localized and progressive brittle failure around an opening does not mean whole collapse of an excavated opening. But, for many cases, it may induce temporary stopping of excavation works and reexamination of the current supporting system, which can result in delay of the entire construction works and additional construction cost. In this paper, the characteristics of the brittle failure around an opening with stress level and tunnel shape was studied by the biaxial compressive test using scaled specimen and by the numerical simulation with $PFC^{2D}$. The biaxial test results were well coincided with the stress induced failure patterns around the excavated openings observed and monitored in the in-situ condition. For the circular part of the opening wall, the stress induced cracks initially occurred at the wall surface in the direction of the minimum principal stress and contributed to the localized notch shaped failure region having a certain range of angle. But for the corner and straight part of the opening wall, the cracks initiated at sharp corners were connected and coalesced each other and with existing micro cracks. Further they resulted in a big notch shaped failure region connecting two sharp corners.

• Tunnel and Underground Space
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• v.23 no.5
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• pp.353-361
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• 2013

Previous studies for analyzing optimal haulage routes of dump trucks in open pit mines mostly used raster data. However, the raster data has several problems in performing optimal route analyses: (1) the jagged appearance of haulage roads according the cell resolution often causes overestimation of the travel cost; (2) it difficult to trace the topological relationships among haulage roads. These problems can be eliminated by using vector network data, however a new method is required to reflect the performance characteristics of a dump truck according to terrain gradient changes. This study presents a new method to create vector network data with the consideration of terrain gradient for analyzing optimal haulage routes of dump trucks in open pit mines. It consists of four procedures: (a) creating digital elevation models, (b) digitizing haulage road networks, (c) calculating the terrain gradient of haulage roads, and (d) calculating the average speed and travel time of a dump truck along haulage roads. A simple case study at the Roto South pit in the Pasir open pit coal mine, Indonesia is also presented to provide proof that the proposed method is easily compatible to ArcGIS Network Analyst software and is effective in finding optimal haulage routes of dump trucks with considering terrain gradient in open pit mines.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.36S no.2
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• pp.69-80
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• 1999

Recently, social requirements of personal identification techniques are rapidly expanding in a number of new application ares. Especially fingerprint recognition is the most important technology. Fingerprint recognition technologies are well established, proven, cost and legally accepted. Therefore, it has more spot lighted among the any other biometrics technologies. In this paper we propose a new on-line fingerprint recognition algorithm for non-inked type live scanner to fit their increasing of security level under the computing environment. Fingerprint recognition system consists of two distinct structural blocks: feature extraction and feature matching. The main topic in this paper focuses on the feature matching using the fingerprint minutiae (ridge ending and bifurcation). Minutiae matching is composed in the alignment stage and matching stage. Success of optimizing the alignment stage is the key of real-time (on-line) fingerprint recognition. Proposed alignment algorithm using clique shows the strength in the search space optimization and partially incomplete image. We make our own database to get the generality. Using the traditional statistical discriminant analysis, 0.05% false acceptance rate (FAR) at 8.83% false rejection rate (FRR) in 1.55 second average matching speed on a Pentium system have been achieved. This makes it possible to construct high performance fingerprint recognition system.