• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.4
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• pp.1899-1911
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• 2018

In this work, we propose a concurrency control scheme in object-oriented database (OODB). Since an OODB provides complex modeling power than the conventional relational databases, a concurrency control technique in OODB is also rather complicated and has influence on the overall performance. Thus, it is very important to develop a concurrency control technique with less overhead. The proposed scheme deals with class hierarchy that is a key concept in OODBs. The proposed scheme is developed on implicit locking scheme. Also, the proposed scheme is designed using data access frequency in order to reduce locking overhead than implicit locking. It means that, if access frequency information is not available, the proposed scheme works just like the existing implicit locking, In our work, the correctness of the proposed scheme is proved. The performance is analyzed depending on access types. Also, it is proved that our scheme performs works much better than the implicit locking does.

• Journal of Gifted/Talented Education
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• v.23 no.6
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• pp.1077-1098
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• 2013

Science gifted students enrolled in a program, where classes had either explicit or implicit instruction about self-directed learning, were asked to write what was satisfying after each class. This process was part of the evaluation of the program. Students' descriptions related to self-directed learning are compared in these two classes, one with explicit instruction and the other with implicit instruction. First, most of the components related to self-directed learning, which were reported in the previous research articles, were mentioned in students evaluation. If there was any specific description regarding what was satisfying, there were components of self-directed learning. Students descriptions were consistent with list of self-directed learning components, which was constructed based on the previous research. Therefore it may be concluded that students recognized most of the reported self-directed learning components and satisfied with them. Second, There were differences in the evaluation of two types of classes. The evaluation of class with explicit instruction contained more self-directed learning components more frequently. For example, students worked in small groups in both classes. However more students mentioned small groups in classes with explicit instruction. As a result the explicit instruction appears to be more effective for students to recognize the self-directed learning components. However some of the components mentioned in classes with implicit instruction were not mentioned in the classes with explicit instruction. Therefore classes with explicit and implicit instructions are complimentary with each other and both instructions are necessary.

• Korean Journal of Culture and Social Issue
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• v.23 no.4
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• pp.497-525
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• 2017

This study verified whether university students of Gwangju and Jeollanam-do recall negative information like violence and death faster than positive information like democratic community about the May 18 Gwangju democratic movement in implicit dimension. University students of Gwangju responded faster when the May 18 combined with the pictures of negative content. However, university students of Jeollanam-do responded marginally faster when the May 18 combined with the pictures of positive content. In addition, the students performed implicit evaluation test towards the May 18. The students of Gwangju showed a slightly negative attitude towards the May 18, while the students of Jeollanam-do showed a positive attitude towards the May 18. This study acquires significance because it confirmed that university students of Gwangju have an implicit representation similar to trauma and a terrible feeling about the May 18.

• 한국전산유체공학회:학술대회논문집
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• 1999.11a
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• pp.17-22
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• 1999

Convergence characteristics and efficiency of three implicit approximate factorization schemes(ADI, DDADI and MAF) are examined using 2-Dimensional compressible upwind Navier-Stokes code. Second-order CSCM(Conservative Supra Characteristic Method) upwind flux difference splitting method with Fromm scheme is used for the right-hand side residual evaluation, while generally first-order upwind differencing is used for the implicit operator on the left-hand side. Convergence studies are performed using an example of the flow past a NACA0012 airfoil at steady transonic flow condition, i. e. Mach number 0.8 at $1.25^{\circ}$ angle of attack. The results were compared with other computational results in order to validate the current numerical analysis. The results from the implicit AF algorithms were compared well in low surface with the other computational results; however, not well in upper surface. It might be due to lack of the grid around the shock position. Because the algorithm minimizes the errors of the approximate decomposition, the improved convergence rate with MAF were observed.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.12 no.2
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• pp.181-186
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• 2012

This paper proposes a method for evaluating web pages by considering implicit user reaction on web pages. Usually users spend more time and make more reactions, such as clicking, dragging and scrolling, while reading interesting pages. Based on this observation, a web page evaluation method by observing implicit user reaction is proposed. The system is designed with Ajax for observing user reactions, and neural networks for learning correlation between user reactions and usefulness of pages. The amounts of each type of user reactions are inputted to neural networks. Also the numbers of characters and images of pages are used as inputs because the amount of users' behaviors has a tendency to increase as the length of pages increase. The experiment is conducted with 113 people and 74 pages. Each page is ranked by users with a questionnaire. The proposed method shows more close ranking results to the user ranks than Google. That is, our system evaluates web pages more closely to users' viewpoint than Google. Although our experiment is limited, our result shows powerful potential of new element for web page evaluation. Some approaches evaluate web pages with their contents and some evaluate web pages with structural attributes, particularly links, of pages. Web page evaluation is for users, so the best evaluation can be done by users themselves. So, user feedback is one of the most important factors for web page evaluation. This paper proposes a new method which reflects user feedbacks on web pages.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.2
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• pp.1054-1063
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• 2015

This study is to verify the effect of similarity of expanded-product, brand concepts of parent-brands and implicit theory of customers on the brand-extension evaluation, in order to reduce the risk of brand extension. First, this research documents how the similarity between the parent-brands and expanded-products affect brand-extension evaluations as a main effect variable. Second, this study examines the moderating effect of the brand concepts of parent-brands on the brand-extension evaluation. Third, this research documents how implicit theories regarding personality affect consumer evaluations about the brand-extension. The study assumes and tests that consumers in the group of incremental theorists are more accepting of brand-extensions than consumers in the group of entity theorists. The result figures out the implicit theory customers has some moderating effect on the evaluations, yet the direction of the effects is contrary to expectations.

• Korean Journal of Computational Design and Engineering
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• v.12 no.3
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• pp.220-232
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• 2007

Current geometric modeling and analysis are commonly based on B-Rep modeling and a finite elements method respectively. Furthermore, it is difficult to represent an object whose material property is heterogeneous using the B-Rep method because the B-Rep is basically used for homogeneous models. In addition, meshes are required to analyze a property of a model when the finite elements method is applied. However, the process of generating meshes from B-Rep is cumbersome and sometimes difficult especially when the model is deformed as time goes by because the topology of deforming meshes are changed. To overcome those problems in modeling and analysis including homogeneous and heterogeneous materials, we suggest a unified modeling and analysis method based on implicit representation of the model using R-function which is suggested by Rvachev. For implicit modeling of an object a distance field is approximated and blended for a complex object. Using the implicit function mesh-free analysis is possible where meshes are not necessary. Generally mesh-free analysis requires heavy computational cost compared to a finite elements method. To improve the computing time of function evaluation, we utilize GPU programming. Finally, we give an example of a simple pipe design problem and show modeling and analysis process using our unified modeling and analysis method.

• Proceedings of the Korea Society for Simulation Conference
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• 2005.11a
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• pp.71-76
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• 2005

XML is rapidly becoming one of the most widely adopted technologies for information exchange and representation on the World Wide Web. However, the large part of data is still stored in a relational database. Hence, we need to convert relational data into XML documents. The most important point of the conversion is to reflect referential integrities In relational schema model to XML schema model exactly. Until now, FT, NeT and CoT are suggested as existing approaches for conversion from the relational schema model to the XML schema model but these approaches only reflect referential integrities which are defined explicitly for conversion. In this paper, we suggest an algorithm for automatic extraction of implicit referential integrities such as foreign key constraints which is not defined explicitly in the initial relational schema model. We present translated XML documents by existing algorithms and suggested algorithms as comparison evaluation. We also compare suggested algorithm and conventional algorithms by simluation in accuracy part.

• Journal of the Korean Society for Library and Information Science
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• v.52 no.4
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• pp.91-110
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• 2018

We proposed a video summarization algorithm based on an ERP (Event Related Potentials)-based topic relevance model, a MMR (Maximal Marginal Relevance), and discriminant analysis to generate a semantically meaningful video skim. We then conducted implicit and explicit evaluations to evaluate our proposed ERP/MMR-based method. The results showed that in the implicit and explicit evaluations, the average scores of the ERP / MMR methods were statistically higher than the average score of the SBD (Shot Boundary Detection) method used as a competitive baseline, respectively. However, there was no statistically significant difference between the average score of ERP/MMR (${\lambda}=0.6$) method and that of ERP/MMR (${\lambda}=1.0$) method in both assessments.

• Journal of the Korea Society for Simulation
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• v.18 no.2
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• pp.57-64
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• 2009

Stable and effective constraint enforcement system is one of the crucial components for physically-based dynamic simulations. This paper presents analysis and evaluation for traditional constraint enforcement systems(Lagrange Multiplier method, Baumgarte stabilization method, Post-stabilization method, Implicit constraint enforcement method, Fast projection method) to provide a guideline to users who need to integrate a suitable constraint enforcement system into their dynamic simulations. The mathematical formulations for traditional constraint enforcement systems are presented in this paper. This paper describes a summary of evaluation which consists of constraint error comparison, computational cost, and dynamic behavior analysis to verify the efficiency of each traditional constraint enforcement system.