• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.1A
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• pp.1-9
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• 2005

We have studied the dispersion properties of a 40 channel x 10 Gbit/s wavelength division multiplexer(WDM) transmission link using standard single mode fiber with all EDFA amplification over 30 x 100 km spans. The dispersion map of the link was investigated by adding fiber sections with positive or negative dispersion at the transmitter, within each amplifier span, and at the receiver. Optimum combinations of these dispersive fiber lengths were attained to significantly enhance the overall transmission performance.

• The Journal of the Korea Contents Association
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• v.9 no.6
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• pp.45-52
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• 2009

Recently, we started a project development of the digital expert system for the product design supporting in manufacturing industry. This digital expert system is used to the engineers in manufacturing industry for the process control, production management and system management. In this paper, we develop the ontology based inference engine shell for building of expert system. This expert system shell included a various functions which of Korean language supporting, graphical ontology map modeling interface, fuzzy rule definition function and etc. And, we introduce the knowledge representation method for the ontology map building and ontology based fuzzy inferencing method.

• Journal of Broadcast Engineering
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• v.24 no.4
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• pp.564-572
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• 2019

With the development of deep learning, the performance of facial landmark detection methods has been greatly improved. The heat map regression method, which is a representative facial landmark detection method, is widely used as an efficient and robust method. However, the landmark coordinates cannot be directly obtained through a single network, and the accuracy is reduced in determining the landmark coordinates from the heat map. To solve these problems, we propose to combine integral regression with the existing heat map regression method. Through experiments using various datasets, we show that the proposed integral regression network significantly improves the performance of facial landmark detection.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.6
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• pp.11-19
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• 2018

Recently, many companies offer various web-based map that is based on GIS(Geographic Information System) information. Google Map, Open street, Bing Map, Naver Map, Daum Map, Vwolrd Map, etc are the few examples of such system. In this paper, we propose a method to visualize ocean forecasting model data considering the flow diagram of tidal current, streamline expression algorithm, and user convenience by using vector field data information that is currently being served. It is confirmed that the proposed method of the flow diagram of tidal current, and stream line expression algorithm is faster than that of conventional ocean prediction model data by more than 2 times.

• Journal of KIISE:Computing Practices and Letters
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• v.14 no.7
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• pp.728-732
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• 2008

GeoRSS is RSS which contains geospatial information, and it supports to supply diverse kinds of data through mash-up map service like the google map. It helps to implement efficient web service with simple java-scripts, but sometimes initial page loading takes too much time and causes heavy traffic when it includes lots of multimedia data. In this paper, we propose a splitting method of GeoRSS for fast accessing. As the result of experiments, we achieved improvement of browsing speed and reducing of initial data traffic.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.9 no.5
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• pp.225-232
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• 2009

In this paper, a new face detection method based on pupil color distribution maps with the frequency under the illumination variance is proposed. Face-like regions are first extracted by applying skin color distribution maps to a color image and then, they are reduced by using the standard deviation of chrominance components. In order to search for eye candidates effectively, the proposed method extracts eye-like regions from face-like regions by using pupil color distribution maps. Furthermore, the proposed method is able to detect eyes very well by segmenting the eye-like regions, based on a lighting compensation technique and a segmentation algorithm even though face regions are changed into dark-tone due to varying illumination conditions. Eye candidates are then detected by means of template matching method. Finally, face regions are detected by using the evaluation values of two eye candidates and a mouth. Experimental results show that the proposed method can achieve a high performance.

• The Journal of Korean Association of Computer Education
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• v.20 no.1
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• pp.75-86
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• 2017

E-learning has become one of the popular educational method in these day. In recognition of the growing e-learning, numerous researchers of S&T have utilized for the training aimed at enhancing competency. In the circumstances, previous studies have yield interesting results regarding certain factors that competency based programs may increase effectiveness of education. Therefore this research described here contributes to design competency modeling and education roadmap for human resource in S&T. The study uses survey, FGI, delphi technique, and expert workshop for selecting the main competencies. In particular, the results are including training roadmap of 5 level in each of two groups as researchers and S&T managers. These findings can be possible to develop customized programs and supported long-term career development path plan for human resource in S&T.

• Journal of KIISE
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• v.43 no.5
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• pp.524-530
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• 2016

The desire to access data faster and the growth of next-generation memories such as non-volatile memories, contribute to the development of research on memory file systems. It is recommended that memory mapped file I/O, which has less overhead than read-write I/O, is utilized in a high-performance memory file system. Memory mapped file I/O, however, brings a page table overhead, which becomes one of the big overheads that needs to be resolved in the entire file I/O performance. We find that same overheads occur unnecessarily, because a page table of a file is removed whenever a file is opened after being closed. To remove the duplicated overhead, we propose the mapping cache, a technique that does not delete a page table of a file but saves the page table to be reused when the mapping of the file is released. We demonstrate that mapping cache improves the performance of traditional file I/O by 2.8x and web server performance by 12%.

• Journal of Broadcast Engineering
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• v.22 no.4
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• pp.473-483
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• 2017

Since the advent of 3D and UHD contents, demand for high-quality panoramic images has been increasing. The UWV(Ultra-Wide Viewing) service uses a wider viewing angle than conventional panoramas to provide a lively experience for users and enhance their understanding of the event. In this paper, we propose a spatial adjacency map generation method and an UWV file storage format technology to provide UWV service. The spatial adjacency map measures the similarity between images and generate the position information of the images based on similarity. And the stitching time of the image can be shortened through the generated position information. Through the spatial adjacency map, we generate the large screen content quickly. The UWV file format which is based on ISOBMFF process spatial adjacency map and videos and support random access. In this paper, we design the UWV player to verify the spatial adjacency map and UWV file format and show the result of experiments.

• Journal of Korea Game Society
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• v.17 no.5
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• pp.123-132
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• 2017

The path-finding algorithm refers to an algorithm for navigating the route order from the current position to the destination in a virtual world in a game. The conventional path-finding algorithm performs graph search based on cost such as A-Star and Dijkstra. A-Star and Dijkstra require movable node and edge data in the world map, so it is difficult to apply online games with lots of map data. In this paper, we provide a Heuristic-based Genetic Algorithm Path-finding(HGAP) using Genetic Algorithm(GA). Genetic Algorithm is a path-finding algorithm applicable to game with variable environment and lots of map data. It seek solutions through mating, crossing, mutation and evolutionary operations without the map data. The proposed algorithm is based on Binary-Coded Genetic Algorithm and searches for a path by performing a heuristic operation that estimates a path to a destination to arrive at a destination more quickly.