• Journal of the Korean Society for information Management
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• v.23 no.2
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• pp.147-165
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• 2006

The explosive growth of Web-based educational resources requires a new approach for accessing relevant information effectively. Social searching in the context of social navigation is one of several answers to this problem, in the domain of information retrieval. It provides users with not merely a traditional ranked list, but also with visual hints which can guide users to information provided by their colleagues. A personalized and context-dependent social searching system has been implemented on a platform called KnowledgeSea II, an open-corpus Web-based educational support system with multiple access methods. Validity tests were run on a variety of aspects and results have shown that this is an effective way to help users access relevant, essential information.

• Journal of information and communication convergence engineering
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• v.7 no.4
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• pp.475-479
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• 2009

In ad hoc network, the scarce energy management of the mobile devices has become a critical issue in order to extend the network lifetime. Current research activity for the Minimum Energy Multicast (MEM) problem has been focused on devising efficient centralized greedy algorithms for static ad hoc networks. In this paper, we consider mobile ad hoc networks(MANETs) that could provide the reliable monitoring and control of a variety of environments for remote place. Mobility of MANET would require the topology change frequently compared with a static network. To improve the routing protocol in MANET, energy efficient routing protocol would be required as well as considering the mobility would be needed. In this paper, we propose a new method, the CACH(Context-aware Clustering Hierarchy) algorithm, a hybrid and clustering-based protocol that could analyze the link cost from a source node to a destination node. The proposed analysis could help in defining the optimum depth of hierarchy architecture CACH utilize. The proposed CACH could use localized condition to enable adaptation and robustness for dynamic network topology protocol and this provide that our hierarchy to be resilient. As a result, our simulation results would show that CACH could find energy efficient depth of hierarchy of a cluster.

• The Journal of the Acoustical Society of Korea
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• v.18 no.8
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• pp.3-8
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• 1999

Previous variable vocabulary speech recognition systems with context-independent acoustic modeling, could not represent the effect of neighboring phonemes. To solve this problem, we use allophone-based context-dependent acoustic model. This paper describes the method to improve acoustic model of the system effectively. Acoustic model is improved by using allophone clustering technique that uses entropy as a similarity measure and the optimal allophone model is generated by changing the number of allophones. We evaluate performance of the improved system by using Phonetically Optimized Words(POW) DB and PC commands(PC) DB. As a result, the allophone model composed of six hundreds allophones improved the recognition rate by 13% from the original context independent model m POW test DB.

• Journal of the Korea Society of Computer and Information
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• v.10 no.3 s.35
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• pp.119-132
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• 2005

The health care system revolutionized by the use of information and communication technologies. Computer information processing and electronic communication technologies play an increasingly important role in the area of health care. We propose a new role based access control model for pervasive health care systems, which changed location, time, environment information. Also our model can be solved the occurrence of an reduction authority problem to pervasive health care system at emergency environment. We propose a new role based access control model for pervasive health care systems, which combines role-to-role delegations, negative permission, context concept and dynamic context aware access control. With out approach we aim to preserver the advantages of RBAC and offer groat flexibility and fine-grained access control in pervasive healthcare information systems.

• ETRI Journal
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• v.41 no.3
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• pp.371-382
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• 2019

Machine reading comprehension is the task of understanding a given context and finding the correct response in that context. A simple recurrent unit (SRU) is a model that solves the vanishing gradient problem in a recurrent neural network (RNN) using a neural gate, such as a gated recurrent unit (GRU) and long short-term memory (LSTM); moreover, it removes the previous hidden state from the input gate to improve the speed compared to GRU and LSTM. A self-matching network, used in R-Net, can have a similar effect to coreference resolution because the self-matching network can obtain context information of a similar meaning by calculating the attention weight for its own RNN sequence. In this paper, we construct a dataset for Korean machine reading comprehension and propose an $S^2-Net$ model that adds a self-matching layer to an encoder RNN using multilayer SRU. The experimental results show that the proposed $S^2-Net$ model has performance of single 68.82% EM and 81.25% F1, and ensemble 70.81% EM, 82.48% F1 in the Korean machine reading comprehension test dataset, and has single 71.30% EM and 80.37% F1 and ensemble 73.29% EM and 81.54% F1 performance in the SQuAD dev dataset.

• Korean Journal of Human Ecology
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• v.20 no.3
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• pp.595-609
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• 2011

This study examine the mediating role of teacher-child relationships on children's effortful control and problem behaviors. Boys and girls were analyzed separately. Participants were 221 children(l21 boys, 100 girls; aged 4-5), their mothers and 19 child care teachers. The teachers completed rating scales to measure the perception of teacher-child relationships and the children's problem behaviors. Children's effortful control was rated by the mother's questionnaire. The collected data was analyzed using descriptive statistics, t-tests, Pearson's correlations, and hierarchical multiple regressions. Results indicated that children's effortful control was negatively related to their problem behaviors. In addition, the associations between children's effortful control and their aggressive behaviors were mediated by conflictual teacher-child relationship. Also, the relation of girl's effortful control and her withdrawal behavior was partially mediated by conflictual teacher-child relationship. Finally, the association between boy's effortful control and his withdrawal behavior was mediated by close teacher-child relationship. Results suggest the importance of teacher-child relationships in the context of intervention planning for preschooler's problem behaviors.

• Korean Journal of Health Education and Promotion
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• v.32 no.3
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• pp.57-71
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• 2015

Objectives: The purpose of this study was to investigate the effect of problem drinking on life satisfaction and to analyze the mediating effect of family conflict and depression between two variables. Methods: The data of this study were selected in the 9th Korea Welfare Panel Survey(KYPS, 2014). The SPSS Ver. 18.0 statistical package was used for descriptive statistics analysis, correlation analysis, and hierarchical regression analysis. Results: The major findings were as follows; First, problem drinking was found to have a negative impact on family conflict, depression, and life satisfaction. Second, family conflict and depression were identified to cause decreasing life satisfaction. Third, family conflict and depression was found to have a mediating effect between problem drinking and life satisfaction. Conclusions: In order to enhance life satisfaction through overcoming problem drinking, drinking prevention programs and recreational programs based on economic and social context are required.

• Journal of the Korean School Mathematics Society
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• v.2 no.1
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• pp.79-91
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• 1999

The aim of this study focused on student-centered learning not teacher-centered teaching in middle school math classes. This study was performed to check the growth of students' problem-solving abilities, learning attitudes and changes in learning motivation among affective characteristics. The results of this study is as followings: 1) The controlled group a heterogeneous group which had classes in a math room, had more meaningful growth than the uncontrolled group. The results of the study show that the problem-solving abilities of the high-leveled group were better than those of the low-leveled group. 2) The controlled group has shown meaningful difference in their mean in learning aptitude test and attitude test converted their score into 100 points than uncontrolled group, and various kinds of learning materials suitable for problem solving are proved as a good learning factor to induce students' motivation and interest. 3) Students prefer to have classes in a math room to the small-sized and large-numbered classrooms. The atmosphere in a math room is more suitable to improving their problem-solving abilities. In this context, the classes performed in a math room are fairly positive. Consequently, students' leveled learning activities performed in a math room can get their learning motivation and attention from those who are lack of interest and think math is difficult and be effective to increase their problem-solving abilities as a learning method for acquiring the whole course of solving the problems.

• Journal of the Korea Society of Computer and Information
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• v.13 no.2
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• pp.59-66
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• 2008

Although the acquisition of information may be done individually, knowledge is created from the social context of peers, teachers. And feedback on the appropriateness and effectiveness of their knowledge and skill is commonly received. Learning occures effectively within environment that have shared understanding of problems and various tools to solve problems. The purpose of this study is to apply the main principles of creative Problem solving and develop e-PBL(Problem-Based Learning) to enhance creative problem solving skill. In this research, the group of students who studied by means of e-PBL based on web 2.0 showed much more satisfaction and problem solving skill than the other group of students who did by e-Learning.

• Journal of The Korean Association For Science Education
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• v.17 no.1
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• pp.11-19
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• 1997

Students' protocols obtained from think-aloud interviews were analyzed in the aspects of the success at first two problem-solving stages (understanding and planning), the time to complete a problem, the time at each problem-solving stage, the number of transition, and the transition rate. These were compared in the aspects of the context of problem, the success in solving problem, students' logical reasoning ability, spatial ability, and learning approach. The results were as follows:1. Students tended to spend more time in everyday contexts than in scientific contexts, especially at the stages of understanding and reviewing. The transition rate during solving a problem in everyday contexts was greater than that in scientific contexts. 2. Unsuccessful students spent more time at the stage of understanding, but successful students spent more time at the stage of planning. 3. Students' logical reasoning ability, as measured with the Group Assessment of Logical Thinking, was significantly correlated with the success in solving problem. Concrete-operational students spent more time in completing a problem, especially understanding the problem. 4. Students' spatial ability, as measured with the Purdue Visualization of Rotations Test and the Find A Shape Puzzle, was significantly correlated with their abilities to understand a problem and to plan for its solution. 5. Students' learning approach, as measured with the Questionnaire on Approaches to Learning and Studying, was not significantly correlated with the success in solving problem. However, the students in deep approach had more transitions and greater transition rates than the students in surface approach.