• Journal of Broadcast Engineering
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• v.2 no.2
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• pp.206-215
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• 1997

We pror.a;e a H.263-based video ceder with two-layer ocalability. The bare layer is ceded by using the default H.263 axling algorithms to achieve high compresred video data and the enhanced layer is axied by enhanced axling such as HVS-based quantization updating. The enhanced layer contains only arled refinement data for the OCT coefficients of the bare layer. Bitstream syntax and semantics for enhancement layer are designed and quantizer design using the HVS is pror.ooed. Data from the two layers are combined after inverse quantization and inverse OCT prcx:esses in the deaxier. We show with e~rirrental results that the pror.a;ed layered arlee achieves comparable picture quality with non-layered arlee at bitrates of 30 kbr;s or less. Overhead information for the bitstream layer can 00 limited to less than 0.5 kbits/frame.

• The Journal of the Korea Contents Association
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• v.5 no.4
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• pp.1-10
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• 2005

After Yahoo Korea opened up the Internet portal market in Korea in 1997, the Korean portal market has experienced fierce competition in the beginning of 2000s. After that period, however, Korean portal market looks relatively stable with top five rankers forming oligopoly and shows that Arthur's claim of network externalities can be applied to the portal industry. In this paper, based on case study of the Korean portals we empirically examined how portals have developed and evolved. In this course, we also investigated the sources of portal's competitiveness. The findings of the research suggest that portals develop and evolve through the reflexive four stages in which they compete over different goals: 1) service quality, 2) critical mass of customers, 3) interpersonal interactivity, and 4) innovative service. According to this framework of portal's evolution, we show that top ranking portals in the present have succeeded in accomplishing the goals of each stage.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.20 no.3
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• pp.265-272
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• 2007

The finite element linear buckling analysis of folded plate structures using adaptive h-refinement methods is presented in this paper. The variable-node flat shell element used in this study possesses the drilling D.O.F. which, in addition to improvement of the element behavior, permits an easy connection to other elements with six degrees of freedom per node. The Box-typed structures can be analyzed using these developed flat shell elements. By introducing the variable-node elements some difficulties associated with connecting the different layer patterns, which are common in the adaptive h-refinement on quadrilateral mesh, can be overcome. To obtain better stress field for the error estimation, the super-convergent patch recovery is used. The convergent buckling modes and the critical loads associated with these modes can be obtained.

• Journal of Digital Convergence
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• v.16 no.9
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• pp.489-495
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• 2018

The purpose of this study was to investigate the effect of fouls on performance in field hockey games. A total of 33 matches and 2101 fouls from 10 teams participated in the 2017 World League SEMI-FINAL tournament were analysed by region, race, type, and cause. The total data that is analysed by SportsCode and SPSS(correlation analysis & chi-square test)have showed that the top ranked countries had a higher foul frequency than the lower ranked nations. According to the situation that has showed the result of the analysis, it showed that there was no difference between the results analysed on the foul type and the attacking and defence situation but it has indicated that area, game situation and the cause of fouls showed there was a significant difference. On these results, it is hoped to use fouls as one of the tactical means in women's field hockey games.

• The Journal of Society for e-Business Studies
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• v.25 no.3
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• pp.77-93
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• 2020

The literature has reported that hierarchical classification methods generally outperform the flat classification methods for a multi-class document classification problem. Unlike the literature that has constructed a class hierarchy, this paper evaluates the performance of hierarchical and flat classification methods under a situation where the class hierarchy is predefined. We conducted numerical evaluations for two data sets; research papers on climate change adaptation technologies in water sector and 20NewsGroup open data set. The evaluation results show that the hierarchical classification method outperforms the flat classification methods under a certain condition, which differs from the literature. The performance of hierarchical classification method over flat classification method depends on class similarities at levels in the class structure. More importantly, the hierarchical classification method works better when the upper level similarity is less that the lower level similarity.

• The Journal of the Korea Contents Association
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• v.15 no.7
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• pp.228-243
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• 2015

This study analyzed the process of change related to how long term laid off workers experienced layoff and the subsequent period of unemployment using a phenomenological method. The subjects of this study were five laid off workers whose average period of unemployment was 8 years and 4 months, and they were surveyed through in depth interviews. By in depth interviews based on a semi structured questionnaire, data were collected about the subjects' psychological experiences at the time of layoff, continuous psychological or physical changes after the layoff, current state, coping methods during the period of unemployment, etc. From the results of the survey were derived 21 sub themes and 5 main themes that comprehended the sub themes. The five main themes were 'emotion and perception on and after layoff,' 'symptoms and changes resulting from the lengthening of layoff,' 'lengthened current state,' 'pattern of social perception,' and 'coping with layoff.' The main themes and the sub themes were described and long term laid off worker' associated experiences were explained in detail. Lastly, long term laid off workers' changes and experiences were discussed based on previous studies.

• Journal of The Korean Association For Science Education
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• v.22 no.1
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• pp.32-39
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• 2002

Three conjectures as the criteria for developing differentiated science learning program for gifted elementary students were derived from the previous research report: 1) The students' reasons why certain educational programs were thought to be interesting or profitable could be classified into the 3 criteria; novelty, curiosity, participation. 2) Students used to think that the programs were interesting if at least anyone of the above 3 criteria is fulfilled. 3) They think, especially, that the programs were profitable if the curiosity criterion is satisfied. To check these conjectures, 47 students were investigated with a Likert type questionnair asking how much the given program is interesting and profitable to themselves after they finished a set of programs for gifted students.

• Journal of The Korean Association For Science Education
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• v.31 no.8
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• pp.1110-1120
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• 2011

The purpose of this study was to investigate teachers' perceptions of gender differences in students' mathematics and science learning ability. The sample included 289 elementary and secondary school gifted teachers. The teachers filled out the survey, asking their perceptions of gender differences in mathematics and science learning ability, as well as of the reasons of the differences. The results were as follows: 1) 65% of the teachers responded that gender differences existed in students' mathematics and science learning ability, 2) 63% of the teachers perceived that the differences began around higher elementary or middle school ages, 3) 57% of the teachers thought that gender differences existed in the high-achieving student group. Teachers perceived the reasons of differences were 1) differences in inborn ability, 2) the different expectation, and 3) the different ways of parental cares. Since teachers' perceptions of students' ability would impact teachers' attitudes on students, implications and suggestions were included in this article to provide teachers insights that promote students' better learning.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.6 no.2
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• pp.133-147
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• 2011

This study presents the credit evaluation model for medical venture business which has been growing within the recent decade. We develop the model with two steps. At the first step, the evaluation indexes for each of the financial and non-financial factors of a firm are listed. At the second step, the weight for each index is measured by using the Analytic Hierarchy Process of Saaty(1980). The financial factors consists of 5 upper level indexes and 10 lower level indexes. The upper level indexes of the financial sector are profitability, safety, utilization, growth, and productivity. And the non-financial factors consists of 5 upper level indexes and 17 lower lever indexes. The upper level indexes in this sector are manager's competence, technical capability, marketability, business validity, and reliability. In order to get the empirical results for our model, we conduct the questionnaire survey targeting the credit assessment officers, who are practicing at the financial institutions or the credit guarantee company located within the Wonju Medical Devices Cluster.

• The KIPS Transactions:PartC
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• v.8C no.1
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• pp.97-104
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• 2001

In this paper, we present a new hierarchical model for performance analysis of channel allocation and packet service protocol in wireless n network. The proposed hierarchical model consists of two parts : upper and lower layer models. The upper layer model is the structure state model representing the state of the channel allocation and call service. The lower layer model, which captures the performance of the system within a given structure state, is the wireless packet retransmission protocol model. These models are developed using SRN which is an modeling tool. SRN, an extension of stochastic Petri net, provides compact modeling facilities for system analysis. To get the performance index, appropriate reward rates are assigned to its SRN. Fixed point iteration is used to determine the model parameters that are not available directly as input. That is, the call service time of the upper model can be obtained by packet delay in the lower model, and the packet generation rates of the lower model come from call generation rates of the upper model.