• Journal of Digital Convergence
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• v.18 no.11
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• pp.259-266
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• 2020

Many developments have been steadily carried out by researchers with applying knowledge-based expert system or machine learning algorithms to the financial field. In particular, it is now common to perform knowledge based system trading in using stock prices. Recently, deep learning technologies have been applied to real fields of stock trading marketplace as GPU performance and large scaled data have been supported enough. Especially, LSTM has been tried to apply to stock price prediction because of its compatibility for time series data. In this paper, we implement stock price prediction using LSTM. In modeling of LSTM, we propose a fitness combination of model parameters and activation functions for best performance. Specifically, we propose suitable selection methods of initializers of weights and bias, regularizers to avoid over-fitting, activation functions and optimization methods. We also compare model performances according to the different selections of the above important modeling considering factors on the real-world stock price data of global major companies. Finally, our experimental work brings a fitness method of applying LSTM model to stock price prediction.

• Geotechnical Engineering
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• v.14 no.2
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• pp.107-126
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• 1998

Ground settlements induced by tunnel excavation cause the foundations of the neighboring building structures to deform. An expert system called NESASS( Neural network Expert System for Adjacent Structure Safety analysis) was developed to analyze the structural safety of such building structures. NESASS predicts the trend of ground settlements resulting from tunnel excavation and carries out a safety analysis for building structures on the basis of the predicted ground settlements. Using neural network technique. the NESASS learns the database consisting of the measured ground settlements collected from numerous actual fields and infers a settlement trend at the field of interest. The NESASS calculates the magnitudes of angular distortion, deflection ratio, and differential settlement of the structure. and in turn, determines the safety of the structure. In addition, the NESASS predicts the patterns of cracks to be formed in the structure, using Dulacska model for crack evaluation. In this study, the ground settlements measured from Seoul subway construction sites were collected and classified with respect to the major factors influencing ground settlement. Subsequently, a database of ground settlement due to tunnel excavation was built. A parametric study was performed to select the optimal neural network model for the database. A comparison of the ground settlement predicted by the NESASS with the measured ones indicates that the NESASS leads to reasonable predictions. The results of confidence evaluation for safety evaluation system of the NESASS are presented in this paper.

• The Journal of Information Systems
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• v.25 no.2
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• pp.1-25
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• 2016

Purpose The innovation capability nowadays has become increasingly prominent in the universities not only for schools but also for teachers. However, due to less attention to the knowledge utilization and management, also some objective constraints, which caused the low level of the innovation capacity for our universities teachers under the current development in China. Meanwhile, transactive memory system (TMS) and knowledge sharing are important contents in knowledge management. The combination of both systems will contribute to a much more comprehensive understanding and performance of knowledge management. The purpose of this study is to investigate the structural relationships between TMS, knowledge sharing, and innovation capability among Chinese university teachers' teams, and to propose the practical implication to integrate effectively internal knowledge of the team to improve innovation capability. Design/methodology/approach In order to exam and verify the hypothesis proposed, we developed a questionnaire with 16 survey items, and each item comes with a five-point Likert-type scale. Hyperlink of online questionnaire was shared through WeChat. It's collected 201 responses from 14 universities in China, and the responders are teaching groups' leaders. And all together 191 responses were filtered out as the valid samples. And we analyze the data set and test research hypotheses by using SPSS 22.0 and AMOS 22.0. Findings All hypotheses are supported. The results reveal that knowledge sharing plays an important role in this study as the mediating role. TMS is positively associated with the innovation capability. And the knowledge sharing plays a significant role as mediating value between them, and influences the TMS's effect on innovation capability. It's thus cleared that if our teachers could well communicate, exchange and collaborate with other teachers in the same group, the innovation capability among the teachers would be improved effectively.

• The Journal of the Korea Contents Association
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• v.10 no.2
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• pp.231-240
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• 2010

The major purpose of this study is to examine how the perfectionism of dance majors affect self-efficacy and performance satisfaction. The sampling of this study was done in 2009, by using purposive sampling method with the subjects who are currently the students of an arts high school and dance majors of a college in Daejeon and Chungcheongnam-do. Specifically, by dividing the district in Chungnam and Daejeon, one arts high school and one college were selected from each district, and 75 dance majors from 4 schools respectively, total 300 students were examined for the study. Among these 300 students, the number of students' questionnaires used in the final analysis is 274, excluding the questionnaires containing inadequate answers. The adequacy of the questionnaire was verified by factor analysis, and the reliability of the questionnaire by reliability analysis. In the matter of reliability, Cronbach's ${\alpha}$ turned up to be over .602. In this study, factor analysis, reliability analysis, regression analysis, and course analysis were done by using SPSS16.0. With the above research method and results, I could come to a conclusion as following. Above all, perfectionism affects the subordinate variable of self-efficacy, the self-control efficacy. That is, with the higher self-oriented perfectionism and the other-oriented perfectionism, self-efficacy increases more as well. Secondly, perfectionism affects performance satisfaction. In other words, the higher self-oriented perfectionism, the higher performance satisfaction. Thirdly, self-efficacy affects performance satisfaction. That is, higher self-control efficacy makes the performance satisfaction higher. Lastly, perfectionism affects self-efficacy and performance satisfaction either directly or indirectly. Now it is obvious that self-efficacy is the variable that intermediate performance satisfaction.

• The Journal of Society for e-Business Studies
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• v.15 no.3
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• pp.99-129
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• 2010

The objective of this research is to identify the factors which influence users' intention to use mobile Internet. There are lots of researches based on Technology Acceptance Model trying to identify the factors which have influence on accepting mobile Internet and its related services. These researches, however, have some limitation in the sense that they focus only on the features of mobile Internet itself while users make overall decision after the comparison of a new service channel with existing service channels in many directions. Therefore, we are going to analyze the impact of users' perception on the difference between mobile and stationary Internet toward their intention to use mobile Internet. We identified the features like ubiquitous availability, context awareness, compatibility, friendliness, and economic value from literature review and developed a structural model about the impact of users' perception on the differences of these features between mobile and stationary Internet toward their intention to use mobile Internet through mediate variables such as perceived ease of use, perceived playfulness, and perceived usefulness. After that, we conducted an experimental analysis for the model, and addressed a solution to rev up the usage of mobile Internet based on the results of the analysis.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.20 no.2
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• pp.181-190
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• 2007

The linkage framework of surface geometric modeling based on the NURBS and shell finite element analysis is developed in this study. In the geometrically exact shell finite element analysis, the accuracy of the analysis strongly depends upon the accurate computation of the surface geometric quantities. Therefore if we obtain the necessary geometric quantities from the NVRBS surface equation, it's possible to construct the effective linkage framework of surface modeling in the CAD systems and shell finite element analysis using geometrically exact shell finite element. Besides, the linkage framework can be applied to the analysis of general and complex surfaces as well as simple surfaces. In this study, the shell surfaces are generated by interpolating given set of data points based on the NURBS surfaces. These data points usually can be obtained from surface scanning. But the representations of the generated NURBS surface are not same to one another. The accuracy depends on the chosen parameterization methods used in NURBS. Therefore, it is needed to select the suitable parameterization method according to the geometry of the surfaces. To verify the performance and accuracy of our developed linkage framework, we solve several well-known benchmark problems and assess the performance of the developed method.

• Journal of the Korea Society of Computer and Information
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• v.16 no.1
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• pp.153-161
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• 2011

Focusing upon the post-adoption stage of IS, this study reasoned that IS users' personality is one of major influencing factors of continuous IS usage intention and empirically examined how the degree of continuous IS usage intention is variable according to the IS users' personality types classified based on MBTI(Myers Briggs Type Indicator). In order to validate the research model and hypotheses, this study made a field survey of 330 IS users and statistically analysed response data. The results of empirical analyses showed that the intent of continuous IS usage was affected by self-efficacy of IS; and self-efficacy by self-leadership of IS; and self-leadership by IS user' personality type and expectation confirmation. That is, it was found that IS users' personality type and three intervening variables(expectation confirmation, self-leadership and self-efficacy) were significant predictors of the intent of continuous IS usage. This study is thought to be contributive to providing the theoretical basis of finding IS success factors in the post-adoption stage and the practical guideline for effective personnel management relevant to IS implementation.

• Korean Journal of Social Welfare
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• v.57 no.3
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• pp.389-413
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• 2005

The OCB(organizational citizenship behavior), spontaneous extra-role behavior of social workers, plays very important role in the provision of qualitative service for the clients and the organizational performance of social welfare agencies. Starting from the importance of OCB for the effective organizational management, this study focuses on the effects of antecedents such as organizational justice(procedural and distributional) and trust in supervisor on the OCB. This study collected data from 360 social workers and 59 their supervisors working in the community welfare centers, paired the self-reported data and the supervisor-rated data, and analyzed the data through the SEM (Structural Equation Modeling) method. The findings of the study show that organizational justice(procedural and distributional) has no direct effect on the OCB, but indirect effect on the OCB through the mediator of trust in supervisor, and that procedural justice has more effect than distributional justice. This study suggests that the management of spontaneous behavior of social workers is not a separated fragmentary phenomenon but should be understood and managed comprehensively in the continuation of the perception of organizational members for the organizational management, the resulting affectivity toward their supervisor, and their behavior in the organizational life.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.3
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• pp.947-956
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• 2013

In this study, WUA (Weighted Usable Area) was calculated to determine ecological flow at the confluence of Nakdong River and Gumho River by using River2D. To calibrate River2D, simulation results of River2D were compared with calibrated HEC-RAS simulation results and the optimum parameters were determined. After parameter calibration, WUA of Zacco platypus and Zacco temmincki which are dominant species in Nakdong River was calculated with changing upstream flowrate. From the result, WUA is changed according to flowrate and growth stage. In the flowrate-WUA/A graph, ecological flow can be determined as $33.3m^3/s{\sim}39.96m^3/s$ in Nakdong River and $3.6m^3/s{\sim}4.32m^3/s$ in Gumho River. After dredging for Four major rivers restoration project, WUA of Zacco platypus and Zacco temmincki were calculated by using the ecological flow. The results show that WUA after dredging are decreased when compared with undredged condition. WUA of Common carp is 2~3 times bigger than WUA of Zacco platypus and Zacco temmincki at the dredged condition in Nakdong River.

• Journal of Korean Tunnelling and Underground Space Association
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• v.9 no.1
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• pp.37-47
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• 2007

The shield tunneling method has been increasingly employed to minimize environmental damages and civil complaints in the populated and developed area. A lining segment, which is a main structure of the shield tunnel, consists of joints. Conventional foreign and domestic design data have been commonly used for design practices without a specific verification of structural analysis models, design load, and the effect of soil characteristics on the performance of lining segment. In this study, the suitability of existing analytic models used for the design of shield tunnel lining segment has been evaluated through a comparison between analytical and numerical solutions. Based on the evaluation of their suitability performed in the study, a full-circumferential beam jointed spring model (1R-S0) is proposed for design practices by considering user's convenience, the applicability of field conditions and the accuracy of analysis result. By using the proposed model, the parameter analysis was performed to investigate the effects of joint stiffness, ground rigidity, joint distribution and the number of joints on the behavior of lining segment. Parameters considered in the investigation have been appeared to affect the behavior of lining segment. Among those parameters, joint stiffness has been appeared to have the most significant effect on the bending moment and displacement of lining segment.