• Journal of the Institute of Electronics Engineers of Korea SC
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• v.47 no.4
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• pp.47-54
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• 2010

We propose a smart human-computer interface replacing conventional mouse interface. The interface is able to control cursor and command action with only hand performing without object. Four finger motions(left click, right click, hold, drag) for command action are enough to express all mouse function. Also we materialize cursor movement control using image processing. The measure what we use for inference is entropy of EMG signal, gaussian modeling and maximum likelihood estimation. In image processing for cursor control, we use color recognition to get the center point of finger tip from marker, and map the point onto cursor. Accuracy of finger movement inference is over 95% and cursor control works naturally without delay. we materialize whole system to check its performance and utility.

• Journal of the Korea Society of Computer and Information
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• v.17 no.6
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• pp.145-152
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• 2012

Due to the large sizes of streaming media, previous delivery techniques are not providing optimal performance. For this purpose, video proxy server is employed for reducing the bandwidth consumption, network congestion, and network traffic. This paper proposes a fast distributed network file system using state transition model in the media streaming system for efficient utilization of video proxy server. The proposed method is composed of three steps: step 1. Training process using state transition model, step 2. base and decision probability generation, and step 3. storing and deletion based on probability. In addition, storage space of video proxy server is divided into each segment area in order to store the segments efficiently and to avoid the fragmentation. The simulation results show that the proposed method performs better than other methods in terms of hit rate and number of deletion. Therefore, the proposed method provides the lowest user start-up latency and the highest bandwidth saving significantly.

• Journal of the Korean Association of Geographic Information Studies
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• v.10 no.2
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• pp.172-183
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• 2007

Recently geospatial information has used widely in many areas such as effective use and management of national land, establishment of city planning, managements of environments and disasters, etc. But present digital map is not suitable for nowadays because of delay of information renewal and changes of topography. In this study, GIS DB construction method was researched through the process of extracting main vector layers such as buildings, roads, contours, etc. from LiDAR data. In order to analyze accuracies of constructed data, the digital topographic maps of 1:1000 scale which were produced by Korea National Geographic Information Institute(NGI) and results of GPS survey were used. Effective DB construction method was suggested through comparing with existing GIS DB construction methods.

• Journal of the Korea Society of Computer and Information
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• v.17 no.12
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• pp.137-148
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• 2012

In this paper, we proposed the location-aware coordinate routing algorithm for improving the performance of routing algorithm by using ZigBee in Smart Grid environment. A distributed address allocation scheme used an existing algorithm that has wasted in address space. The x, y and z coordinate axes from divided address space of 16 bit to solve this problems. However, coordinate routing does not take account of wireless link condition. If wiress link condition is not considered, when the routing table is updated, the nodes with bad link conditions are updated in the routing table and can be chosen as the next hop. This brings out the retransmissions because of received packet's errors. Also, because of these retransmissions, additional power is consumed. In this paper, we propose the location-aware coordinate routing algorithm considering wiress link condition, where reliable data transmission is made and the consumed enegy is minimize. and we compared and connected region and transition region of ZigBee location based routing in the aspect of average number of multi hops, subordinate packet delivery ratio, delay time, and energy consumption of proposed algorithm. It turned out that there were improvements in performances of each items.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.27 no.2
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• pp.261-271
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• 2009

Due to the recent rise of a need for 3 dimensional geospatial information on urban areas, general interest in aerial multi-view cameras has been on an increase. The conventional geospatial information system depends solely upon vertical images, while the multi-view camera is capable of taking both vertical and oblique images taken from multiple directions, thus making it easier for the user to interpret the object. Through our research we developed a prototype of a multi-view camera system that includes a camera system, GPS/INS, a flight management system, and a control system. We also studied and experimented with the camera viewing angles, the synchronization of image capture, the exposure delay, the data storage that must be considered for the development of the multi-view camera system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.3B
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• pp.408-422
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• 2000

In this paper, we propose a generalized vector channel model for wireless communication systems using antenna arrays. The proposed channel model reflects path loss. spatial-temporal variation of shadowing, multipath fading , Doppler effect, spatial distribution of local scatterers and delay spread due to remote dominant scatterers. In addition, we use a discrete ray model in which respective ray signal experiences independent shadowing, fading and Doppler shift, and impinges on antenna arrays at a distinct angle. Based on the proposed mode. we derive the relations on the spatial and temporal correlations of the received signals and implement a spatial channel simulator. By comparing the theoretical values with the simulated ones, we verify the effectiveness of the implemented simulator. The simulator is then used to generate an arbitrary channel impulse response and to analyze the channel characteristics under various environments.

• Journal of KIISE
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• v.43 no.1
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• pp.13-26
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• 2016

This paper proposes a new sound localization algorithm that can improve localization performance based on a tetrahedron-shaped microphone array. Sound localization system estimates directional information of sound source based on the time delay of arrival(TDOA) information between the microphone pairs in a microphone array. In order to obtain directional information of the sound source in three dimensions, the system requires at least three microphones. If one of the microphones fails to detect proper signal level, the system cannot produce a reliable estimate. This paper proposes a tetrahedron- shaped sound localization system with a coordinate transform method by adding one microphone to the previously known triangular-shaped system providing more robust and reliable sound localization. To verify the performance of the proposed algorithm, a real time simulation was conducted, and the results were compared to the previously known triangular-shaped system. From the simulation results, the proposed tetrahedron-shaped sound localization system is superior to the triangular-shaped system by more than 46% for maximum sound source detection.

• The KIPS Transactions:PartA
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• v.8A no.4
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• pp.287-292
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• 2001

Multimedia service systems should have efficient capacity to serve the growing clients and new data. In the general streaming services, users can endure the small amount of time delay at the beginning of service. But they want to have good quality of service. A streaming server tries to transfer video files to clients from a repository of files in real time. The server must guarantee concurrent and uninterrupted delivery of each video stream requested from clients. To achieve its purpose, many stream servers adopt multi-processors, sufficient memory, and RAID or SAN in their systems. In this paper, we propose a Linux-based parallel media streaming server. It is superior to the other systems in the storing structure, fault-tolerance, and service capacity. Since this system supports the web interlace, users can operate easily through the www. This system uses unique striping policy to distribute multimedia files into the parallel storage nodes. If a service request occurs, each storage node transmits striped files concurrently to the client. Its performance is better than the single media streaming service because of the parallel architecture.

• Journal of Korean Society of Transportation
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• v.21 no.3
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• pp.37-46
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• 2003

Over the last few years, the major airports in Asia have been operating at or close to their capacity. As a result, Korea, Japan, China, Hong Kong, Thailand, Malaysia, and Indonesia decided to expedite the development of new airports. Accordingly, some of the existing airports have been completely used as other functions or purposes and the others operated as a domestic airport. In the latter case, re-development plans are needed for idle facilities. This paper evaluates the alternative options for re-development of idle airport facilities of Seoul Gimpo International Airport. The proposed methodology makes it possible to provide a practical and applicable evaluation of airport re-development plan. In particular, it can take into account the qualitative aspects of different interesting groups such as airport experts. passengers and airport peripheral community. The interview was conducted in order to obtain the different groups' view. To evaluate and select the best option of the airport re-development, this study adopted a fuzzy linguistic approach.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.560-560
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• 2015

우리나라 연평균 수자원 총량은 1,297억톤이고 이용가능한 수자원량은 58%(753억톤)이며, 이 중 바다로 유실되는 32%(420톤)를 제외하고 연간 26%(333억톤)을 이용하고 있다. 용도별로 보면 생활용수 75억톤, 공업용수 21억톤, 농업용수 159억톤 및 유지용수 78억톤 등으로 사용되며 농업용수가 약 48%로 가장 많은 양이 차지하고 있다. 농업용수는 국내 수자원 소비량 중 가장 많은 양을 차지하고 있으나, 주기적인 가뭄에 따른 용수 부족이 매년 심각한 문제로 대두되고 있는 실정이며, 이에 대한 대책으로 저수지 준설, 둑 높이기, 다단계 양수장 건설 등을 통한 저수량 확보 사업이 진행되고 있으나 준설 및 둑 높이기시 막대한 사업비와 양수장 조성 공간 부족 등으로 농업용수 확보에 어려움이 발생하고 있다. 국내에서는 수자원 개발 및 친수공간 조성을 목적으로 매년 1,000여건의 하천공사가 실시되고 있으며, 하천공사로 인해 가물막이의 설치 및 해체가 계속적으로 발생하고 있다. 하천공사시 가물막이 설치를 위해 중장비의 출입 반드시 필요하나 중장비 출입이 어려운 지역에서는 공사기간 지연 및 경제성 등의 문제로 어려움을 겪고 있는 실정이다. 이에, 본 연구에서는 휴대용 차수막의 구조개선을 통해 (1) 저수지 증고 및 하천 가물막이에 적합한 설계 및 설치 방법을 개발하고, (2) 수압 및 부유물질에 안전하도록 강도를 개선하였으며, (3) 내구성, 경제성, 유지관리성이 개선된 재이용이 가능한 휴대용 차수막을 개발하였다. 휴대용 차수막 개발로 인해 저수지 증고 및 하천 가물막이 뿐만 아니라 방재 및 레크레이션용도 등 다목적 활용이 높은 것으로 나타나 수자원 분야에 다수 적용될 것으로 기대된다.