• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.6A
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• pp.575-583
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• 2002

JBIG2 is an International Standard fur compression of Bi-level images and documents. JBIG2 supports three encoding modes for high compression according to region features of documents. One of which is generic region coding for bitmap coding. The basic bitmap coder is either MMR or arithmetic coding. Pattern matching coding method is used for text region, and halftone pattern coding is used for halftone region. In this paper, a document is segmented into line-art, halftone and text region for JBIG2 encoding and JBIG2 CODEC is implemented. For efficient region segmentation of documents, region segmentation method using wavelet coefficient is applied with existing boundary extraction technique. In case of facsimile test image(IEEE-167a), there is improvement in compression ratio of about 2% and enhancement of subjective quality. Also, we propose arbitrary shape halftone region coding, which improves subjective quality in talc neighboring text of halftone region.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.9 no.3
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• pp.193-199
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• 2009

Powerline communications (PLC) technology has been discussed and analyzed as a highly potential candidate of wireline access network solutions. In this paper, performance of double binary turbo coded orthogonal frequency division multiplexing (OFDM) system is analyzed and simulated in power line communications channel. In order to make power line channel environments, Bernoulli-Gaussian noise is considered. The performance is evaluated in terms of bit error probability. From the simulation results, it is demonstrated that the double binary turbo coding scheme offers considerable coding gain with reasonable encoding complexity. It is also shown that the system performance can be substantially improved by increasing the number of iterations.

• Journal of the Society of Disaster Information
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• v.2 no.1
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• pp.65-80
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• 2006

Security and Secretary Service is the man who maintains safe condition of boss', following him during all daily schedule and help the boss display his supreme business abilities, settling various affairs The purpose of this study is to examine the role of Security and Secretary Service. To understand the role of Security and Secretary Service, interviews with Security and Secretary Service's. synthesizing records inquire and interviews with present workers, was analyzed. As results of the study, the open coding of grounded theory was 85 categories, 22 lower categories, and 13 upper categories; 7 roles of Security and Secretary Service types out of 13 upper categories were attained. Based on this, from the axial coding a paradigm model related to categories was produced and selective coding the core category, story line development and type were analyzed. Therefore, Security and Secretary Service plays roles: Office manager, Training manager, Information manager, Customer relations manager, Facilitator, Health manager, and Safety manager. Compared with Office secretary, It is said that Health manager, and Safety manager are distinguishing roles. Through the coding process based on grounded theory. For this, based on the writer's theoretical sensitivity and constant comparative analysis, theses as well as writing in each field, data from serial publications and others, the statements of interview subjects were constantly compared and analyzed. Based on these analyses, this study suggests the following: First, the intimidate sample survey is need. Second, professional educational content during the training process of Security and Secretary Services should be strengthened. Third, to expect a more professional role of Security and Secretary Services. the systematic support will be required.

• International Journal of Internet, Broadcasting and Communication
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• v.14 no.4
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• pp.198-205
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• 2022

Along with a variety of coding education, physical computing education for controlling various sensors is being actively conducted for elementary, middle, and high school students in line with the era of the fourth industrial revolution. A problem with physical computing education using Arduino is pin connection errors between Arduino and various sensors. Most of the students who come into contact with the Arduino for the first time often do not know the purpose of the Arduino pin and the connection position of the pin. Also, hardware built with incorrect pin connections to the Arduino board often does not work properly. If this case continues, students will lose interest in coding education. Therefore, in this paper, we implemented an augmented reality application that informs the connection process of the Arduino board and the sensor during physical computing coding education using Arduino, and designed and implemented educational content for the Arduino pin position and connection process. First, we explain the role of the Arduino board and the sensor and the location of the pins. After that, the students run the educational augmented reality educational content using their smartphones and check the correct pin connection process between the Arduino and the sensor. In the physical computing education, augmented reality content is used to increase the understanding and immersion of the class. It is expected that the educational effect will also increase by inducing fun and interest in physical computing coding education.

• Proceedings of the IEEK Conference
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• 2000.07a
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• pp.132-135
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• 2000

In this paper, we propose to exploit a multi-code CDMA scheme for power line communication (PLC) systems, and its performance on non-Gaussian impulse and harmonic noises is presented. The proposed multi-code CDMA scheme utilizes convolutional coding and block interleaving to combat with the non-Gaussian noises, and simulation results indicate effective alleviation of these noises, and thus significant bit error rate improvement by the proposed scheme even under strict restriction of frequency band allowed in PLC systems.

• 한국정보통신설비학회:학술대회논문집
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• 2009.08a
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• pp.72-77
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• 2009

In this paper, performance of a turbo-coded PLC system is analyzed and simulated in a power line communication channel. Since the power line communication system typically operates in a hostile environment, turbo code has been employed to enhance reliability of transmitted data. The performance is evaluated in terms of bit error probability. As turbo decoding algorithms, Max-Log-MAP algorithms are chosen and performances are compared. The results in this paper can be applied to OFDM-based high-speed power line communication systems

• 한국정보통신설비학회:학술대회논문집
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• 2009.08a
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• pp.190-196
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• 2009

In this paper, performance of a turbo-coded OFDM system is analyzed and simulated in a power line communication channel. Since the power line communication system typically operates in a hostile environment, turbo code has been employed to enhance reliability of transmitted data. The performance is evaluated in terms of bit error probability. As turbo decoding algorithms, MAP (maximum a posteriori), Max-Log-MAP, and SOVA (soft decision Viterbi output) algorithms are chosen and their performances are compared. From simulation results, it is demonstrated that Max-Log-MAP algorithm is promising in terms of performance and complexity. It is shown that performance is substantially improved by increasing the number of iterations and interleaver length of a turbo encoder. The results in this paper can be applied to OFDM-based high-speed power line communication systems.

• Journal of Practical Engineering Education
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• v.9 no.1
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• pp.23-30
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• 2017

This is a study on a case applying flipped learning to coding classes that is a college liberal arts course. A required coding class for the students who do not major in computers needs a teaching method differentiated from a coding education for training experts. The present study presented a flipped learning teaching model for the coding education of non-major students, and observed its effect and possibility. Flipped learning enables learners to learn with on-line contents anywhere and anytime they want and concentrate on practice education based on what they learned during class. Accordingly, the study sought for the solution to maximize the efficiency of teaching and learning through flipped learning. A pre and post surveys after applying a flipped learning to a practical class confirmed that the students taught using flipped learning were more positively assessed in learning satisfaction than those taught using a traditional method, and that in academic achievement as well, flipped learning was more effective.

• The Journal of the Korea institute of electronic communication sciences
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• v.10 no.1
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• pp.39-46
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• 2015

The paper studied possibility of improvement of efficient of data processing in the line coder when Hangul syllables in Unicode system is used for the source code. The scrambling in the line coder is to solve the problem happened due to the source code. The study is based on the HDB-3 scrambling method in ITU-T standards that is applied to AMI line coder. The referred data of Hangul syllables and its use frequency which are required to analysis was used the data extracted from the source data of the National Korean Language Institute. According to the analysis, the average 24% scrambling was generated in source code of Hangul syllables in Unicode system. When the referred Hangul syllables was applied to Unicode system, the average 27% scrambling was producted. Total 8,924ea Hangul syllables in 11,172ea Hangul syllables in Unicode system were not scrambled. Therefore the referred Hangul syllables 1,540ea were accepted in the unscrambled code areas. As a result, the existing Unicode Hangul syllable codes can't prevent the scrambling, but it is possible to completely remove the 27% scrambling with new source coding system. And then, it can be improved the data processing efficient upto minimum 27% in line coder by software in presentation layer instead of physical layer.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.1
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• pp.157-164
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• 2012

This paper introduces an implementation of SVC player which runs on Android platform and can play SVC video stream on line from SVC video server. SVC(Scalable Video Coding) is a scalable video encoding technique which supports three scalability such as temporal scalability, spatial scalability, and quality scalability. To implement the SVC player on Android, we implemented a SVC decoder using JSVM open source written in C/C++ as a native part on Android and developed Android UI in Java. Also we built an SVC encoding system off line and an SVC streaming server to conduct on-line SVC streaming experiments. Finally, after we installed the SVC player developed in this paper on Motoroi mobile phone, we evaluated and analyzed on-line streaming performance of the SVC player. The result showed that the player worked well and it had no jitter in streaming with the size of QCIF and 10fps from a fully encoded SVC video source.