• Korean Journal of Culture and Social Issue
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• v.17 no.3
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• pp.287-304
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• 2011

The Purpose of this study is to understand phases and paradigms related to voluntary services offered by undergraduates and the processes in which voluntary services are implemented. For this, interviews for 23(men: 10, women: 13) undergraduates were conducted from Aug., 2008 to Apr., 2009 were conducted and the data collected from those interviews were analyzed on the basis of the Grounded Theory. Main analysis procedure is known as codings(open coding, axial coding, selective coding). This analyses produced 119 concepts, 41 subcategories, and 16 categories in open coding. Then, axial coding was conducted to organize the basic framework of generic relationships among psychological motivation, social context, personal perception, practical action, psychological response, and psychological consequence. Core essence is "Volunteer types are categorized simple practice type, self-serving type, and community type." Finally, undergraduate volunteers were explained in 3 types(simple practice, self-serving, and community) on the basis of paradigms. These results were discussed in terms of further research and limitation.

• The Journal of Information Systems
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• v.28 no.2
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• pp.93-107
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• 2019

Purpose The purpose of this study is to explain the mechanism of user behaviors in password reset context based on descriptive data from conducting interviews. Specifically, this study attempted to describe the process of changing password from the shadow work perspective. Design/methodology/approach This study has interviewed 8 participants who can freely use numerous online web-sites. This study also employed the grounded theory methodology to analyze interview manuscripts. After conducting analyzing the manuscripts, this study has extracted 46 codes in the coding steps and ultimately presented 8 categories by combining similar concepts from those codes. Findings According to the results, this study provides new viewpoints to explain unique user behavior in the password reset context by capturing the shadow work based on the results. This study further offers practical implications to numerous practitioners by finding various codes, which related to users' reaction and behavior.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.45 no.2
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• pp.26-32
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• 2008

Video compression schemes have been developed and used for many years. Currently, H.264/AVC is the most efficient video coding standard. The H.264/AVC baseline profile adopts CAVLC(Context-Adaptive Variable Length Coding) method as an entropy coding method. CAVLC gives better performance in compression ratios than conventional VLC(Variable Length Coding). However, because CAVLC decoder uses a lot of VLC tables, the CAVLC decoder requires a lot of area in terms of hardware. Conversely, since it must look up the VLC tables, it gives a worse performance in terms of software. In this paper, we propose a new hierarchical grouping method for the VLC tables. We can obtain an index of codes in the reconstructed VLC tables by simple arithmetic operations. In this method, the VLC tables are accessed just once in decoding a symbol. We modeled the proposed algorithm in C language, compiled under ARM ADS1.2 and simulated it with Armulator. Experimental results show that the proposed algorithm reduces execution time by about 80% and 15% compared with the H.264/AVC reference program JM(Joint Model) 10.2 and the arithmetic operation algorithm which is recently proposed, respectively.

• Journal of Broadcast Engineering
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• v.18 no.2
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• pp.319-322
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• 2013

Image retrieval research activity has moved its focus from global descriptors to local descriptors of feature point such as SIFT. MPEG is Currently working on standardization of effective coding of location and local descriptors of feature point in the context mobile based image search driven application in the name of MPEG-7 CDVS (Compact Descriptor for Visual Search). The extracted feature points consist of two parts, location information and Descriptor. For efficient image retrieval, we proposed a novel method that is gradual block-based efficient lossy location coding to compress location information according to distribution in images. From experimental result, the number of average bits per feature point reduce 5~6% and the accuracy rate keep compared to state of the art TM 3.0.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.5C
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• pp.496-512
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• 2007

In this paper, we propose a novel JPEG-2000 compressed image retrieval system using feature vector extracted through partial entropy decoding. Main idea of the proposed method is to utilize the context information that is generated during entropy encoding/decoding. In the framework of JPEG-2000, the context of a current coefficient is determined depending on the pattern of the significance and/or the sign of its neighbors in three bit-plane coding passes and four coding modes. The contexts provide a model for estimating the probability of each symbol to be coded. And they can efficiently describe texture images which have different pattern because they represent the local property of images. In addition, our system can directly search the images in the JPEG-2000 compressed domain without full decompression. Therefore, our proposed scheme can accelerate the work of retrieving images. We create various distortion and similarity image databases using MIT VisTex texture images for simulation. we evaluate the proposed algorithm comparing with the previous ones. Through simulations, we demonstrate that our method achieves good performance in terms of the retrieval accuracy as well as the computational complexity.

• Research in Mathematical Education
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• v.18 no.4
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• pp.273-288
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• 2014

In recent years, coding education has been globally emphasized and the Free Semester System will be executed to the public schools in Korea from 2016. With the introduction of the Free Semester System and the rising demand of Computational Thinking (CT) capacity, this research aims to design 'learning environment' in which learners can design and construct mathematical objects through computers and print them out through 3D printers. Furthermore, it will design learning mathematics by constructing the figurate number patterns from 'soma cubes' in the playing context and connecting those to algebraic and combinatorial patterns, which will allow students to experience mathematical connectivity. It is expected that the activities of designing figurate number patterns suggested in this research will not only strengthen CT capacity in relation to mathematical thinking but also serve as a meaningful program for the Free Semester System in terms of career experience as 3D printers can be widely used.

• Journal of IKEEE
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• v.18 no.4
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• pp.630-635
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• 2014

In this paper, hardware architecture of BAE (binary arithmetic encoder) was proposed for HEVC (high efficiency video coding) CABAC (context-based adaptive binary arithmetic coding) encoder. It can encode each bin in a single cycle. It consists of controller, regular encoding engine, bypass encoding engine, and termination engine. The proposed BAE was designed in Verilog HDL, and it was implemented in 180 nm technology. Its operating speed, gate count, and power consumption are 180 MHz, 3,690 gates, and 2.88 mW, respectively.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2000.11b
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• pp.87-92
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• 2000

본 논문에서는 컨텍스트 기반 계층적 열거 부호화를 이용한 무손실 이진 영상 압축 알고리즘을 제안한다. 이진 영상내에 존재하는 인접한 화소간의 상호상관성을 이용하여 이진 영상을 1차원의 수열로 재구성하고, 이에 대해 계층적 열거 부호화를 실행한다. 제안하는 알고리즘은 덧셈 및 비교 연산만으로 구현이 가능하므로 그 복잡도가 매우 낮을 뿐만 아니라, CCITT 테스트 영상을 대상으로 한 부호화 성능 실험에서 우수한 성능을 나타낸다. 부호화 성능 비교에서 이진 영상 부호화 국제표준인 JBIG, G3, G4 및 GIF에 비해 우수한 압축 성능을 보인다.

• The Journal of Information Systems
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• v.30 no.4
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• pp.153-171
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• 2021

Purpose This study is to phenomenologically discover key antecedents and outcomes of behavioral process of SNS users who have multiple SNS sub-accounts. Unlike previous studies that focused on user behavior in the context of a specific SNS platform, this study attempts to describe how and why individual manages their multiple sub-accounts across a variety of SNS platforms. Design/methodology/approach By applying the grounded theory methodology (GTM) to elucidate the unique behavior in SNS platforms, this study has conducted in-depth interview with 14 respondents who handle multiple accounts across the SNS platforms. As a results of analyzing the interview manuscripts, this study has extracted 47 concepts, 10 sub-categories and 6 main categories by conducting open coding, axis coding, and selective coding. Findings By analyzing interview data, this study has derived main categories such as account management, impression management, self-categorization, authority to determine the relationship, digital shadow work, and portfolio SNS accounts from qualitative interview data. This study has also conducted a process analysis that represents how main categories could be inter-related. Based on findings, this study provides a new phenomenological perspective to understand the behavioral process of SNS users' sub-account usage experience.

• International Journal of Advanced Culture Technology
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• v.7 no.4
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• pp.49-55
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• 2019

In the age of information, newly produced knowledge is mostly written in English. Therefore, there has been a strong demand for English language learning in the EFL context. However, most EFL learners possess a lack of interest and motivation in the text-based reading class. In this educational context, film is one of the most widely used materials in English reading classes considering that modern learners are predominantly familiar with various audiovisual materials. The purpose of this study is to investigate how Korean EFL learners experienced in the film-based reading class. Specifically, this study aims to analyze the EFL students' perceptions about the class and learning strategies that they used during the class. In order to comprehensively interpret the EFL learners' experiences in the classroom, a coding system consisting of five categories was developed: report, emotion, reflection, evaluation, future plans. The results of data analysis showed that the use of movies in English reading classes had positive effects on reading comprehension and inference of word meaning. The most frequently used learning strategies were affective strategies which helped them control their emotion, attitude, motivations and values, whereas memorization strategies were rarely used. In this respect, this study suggests that the use of movies in the EFL reading classroom encourage students' attention and help them obtain and activate schema which is useful in gaining a better understanding of text-based reading materials.