• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.4
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• pp.772-780
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• 2008

K-means is one of the simplest unsupervised learning algorithms that solve the clustering problem. However K-means suffers the basic shortcoming: the number of clusters k has to be known in advance. In this paper, we propose extensions of X-means, which can estimate the number of clusters using Bayesian information criterion(BIC). We introduce two different versions of algorithm: modified X-means(MX-means) and generalized X-means(GX-means), which employ one full covariance matrix for one cluster and so can estimate the number of clusters efficiently without severe over-fitting which X-means suffers due to its spherical cluster assumption. The algorithms start with one cluster and try to split a cluster iteratively to maximize the BIC score. The former uses K-means algorithm to find a set of optimal clusters with current k, which makes it simple and fast. However it generates wrongly estimated centers when the clusters are overlapped. The latter uses EM algorithm to estimate the parameters and generates more stable clusters even when the clusters are overlapped. Experiments with synthetic data show that the purposed methods can provide a robust estimate of the number of clusters and cluster parameters compared to other existing top-down algorithms.

• Phonetics and Speech Sciences
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• v.6 no.4
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• pp.141-148
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• 2014

Voice is the most common means for communication, but some people have difficulties in generating voice due to their congenital or acquired disorders. Individuals with speech disorders might lose their speaking ability due to hearing impairment, encephalopathy or cerebral palsy accompanied by motor skill impairments, or autism caused by mental problems. However, they have needs for communication, so some of them use various types of AAC (Augmentative & Alternative Communication) devices in order to meet their communication needs. In this paper, a mobile application for literate people having speech disorder was designed and implemented by developing accurate and fast sentence-completion functions for efficient user interaction. From a user study and the previous study on Korean text-based communication for adults having difficulty in speech communication, we identified functionality and usability requirements. Specifically, the user interface with scanning features was designed by considering the users' motor skills in using the touch-screen of a mobile device. Finally, we conducted the usability test for the application. The results of the usability test show that the application is easy to learn and efficient to use in communication with people with speech disorders.

• Proceedings of the Korean Institute of Interior Design Conference
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• 2005.05a
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• pp.60-63
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• 2005

After 20th century, Data tend to important in a sphere of architecture. In this study such tendency was christened a Data architecture. And The purpose of the study is to define data architecture and to find out of data architecture's merits from a communicational point of view. Above-mentioned Communication means that exchange all kinds of something between each other.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.399-402
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• 1997

The fieldbus is one of the communication networks in control and automation systems and allows the exchange of information between sensors/actuators and controlling elements. By means of the fieldbus, the various field devices can exchange their information among the nodes in the system. In this paper, we implemented the protocol of profibus, a kind of fieldbus for communication in FMS plant model. We applied this fieldbus to the FMS plant model which consists of three stations and eight slave stations.

• Journal of the Korean Graphic Arts Communication Society
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• v.15 no.1
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• pp.85-96
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• 1997

The color difference between original and printed copy is affected mainly by ink trapping and optical properties of overprinted ink layer. Since the general expression itself about ink trapping is affected also by the optical properties, the analysis of color difference using the ink trapping only cannot be certain. This study will show a new approaching method for optical analysis of spectral reflectance and the effect of printing sequence on color difference in multi-color overprints under the condition of excluding completely the ink trapping problems by means of using transparent film as a substrate.

• Journal of the Korean Graphic Arts Communication Society
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• v.15 no.2
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• pp.131-143
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• 1997

Surface sizing is one of the important process to the paper making. Surface sizing had an effect on penetration of oils, physical propertiesm water resistance for the paper. This study was carried out for the purpose of improving printability with surface sizing of domestic newspaper. The samples were prepared by means of TAPPI method(TAPPI 205 om~88), and were wested by IGT printability tester. The results of this study showed that the set-off was reduced on the surface sized with oxidized starch.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2003.09a
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• pp.65-89
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• 2003

Next Highly sophisticated communication generation of the Advanced Electronics and Imaging processing society will require a vast information volume and super high speed signal transport and information instruction. This means that super high technology should be created for satisfying the demand. It's also required the high reliability of the communication system itself, It will be supported the new advanced packaging technology of the 3 Dimensional structured system and system integration technology. Here is introduced the new 3 Dimensional technology for IC nnd LSI packaging and Opt-electronics Packaging of ASET activity in Japan.

• International Journal of Computer Science & Network Security
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• v.22 no.10
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• pp.37-42
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• 2022

Communication as a process of interpreting signs has always existed in people's life. In post-information society, the communication between a person and a technological system through the specific sign-attaching process becomes widespread. Moreover, it somehow replaces usual communication between people. One of the means of communication in the digital space are video games. They not only play an important role in communication processes, but also are a special case of sign-creating and interpreting. The purpose of the article is to examine video games as a space of sign-based communication between a person and a game as a specific digital system. With the help of general scientific and hermeneutic methodology, the analysis of video games as a post-information society phenomenon which people communicate to has been conducted. The process of semiosis as attaching special meanings to signs has been traced in both manipulating in-game objects and characters and understanding rules of an in-game world.

• The Mathematical Education
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• v.49 no.4
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• pp.523-540
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• 2010

The purpose of the study were to analyze MathThematics textbooks and Korean middle school mathematics and to investigate the difference among the textbooks in the view of mathematical communication. According to the results, the textbook developers made a variety of efforts to develope students' mathematical communication ability. Students were encouraged to communicate with others about their mathematical ideas or problem solving processes in words or writing by means of discussion, oral report, presentation, journal, etc. MathThematics textbooks provided student self-assessment opportunity to improve student performance in problem solving, reasoning, and communication. In communication assessment, students can assess their use of mathematical vocabulary, notation, and symbols, the use of graphs, tables, models, diagrams and equation to solve problem and their presentation skills. The assessment activities would make a positive impact on the development of students' mathematical communication ability. MathThematics textbooks provided a variety of problem situation including history, science, sports, culture, art, and real world as a topic for communication, however, the researcher found that some of Korean textbooks depends heavily on mathematical problem situations.

• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.4
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• pp.695-702
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• 2022

Smart railway system, which has been actively studied in recent years, is entering the intelligent stage beyond the automation stage based on ICT (Information & Communication Technology) such as communication technology and information technology. ICT technology used in smart railways is generally supported by various information protection technologies as it is vulnerable to information infringement. As a means of high-speed/mass transportation, it is essential to devise an information protection plan for ICT technology that forms the basis for smartening the railway system. Therefore, this paper presents the necessity of step-by-step information protection that measures for smart railway communication by examining potential risk factors of smart railway communication base and considering information protection factors that can respond to them.