• Journal of the Korean Society of Earth Science Education
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• v.4 no.2
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• pp.116-125
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• 2011

The purpose of this study is to make a Result analysis on the Free Inquiry Method of Elementary school student. Also, this study investigates how free inquiry activities effect the science creative problem solving ability and science process skills of Elementary school student. For this study 150, third year, elementary School students from Busan City were selected. The Inquiry examined the effectiveness of each of the following free inquiry methods: the Program Based Learning method, the Project method, the Independent Investigation Method, the Small Group Inquiry Method, and the Science Notebooks Method. The students were divided into groups in which they incorporated the respective methods into their practice. Test showed the following results: First, the Science Notebooks Method activities proved to be much more effective than the Program Based Learning method, the Project method, the Independent Investigation Method, the Small Group Inquiry Method, and the Science Notebooks Method in terms of developing on science creative problem solving ability. Second, the Project method activities proved to be much more effective than the Program Based Learning method, the Independent Investigation Method, the Small Group Inquiry Method, the Science Notebooks Method in terms of developing on science process skills.

• Journal of Information Processing Systems
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• v.3 no.1
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• pp.33-37
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• 2007

Semantic clustering is important to various fields in the modem information society. In this work we applied the Independent Component Analysis method to the extraction of the features of latent concepts. We used verb and object noun information and formulated a concept as a linear combination of verbs. The proposed method is shown to be suitable for our framework and it performs better than a hierarchical clustering in latent semantic space for finding out invisible information from the data.

• Journal of Drive and Control
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• v.17 no.4
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• pp.54-71
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• 2020

In light of the environmental challenges, energy-saving strategies are currently under investigation in the construction industry. This paper focuses on the energy-saving method used in the hydraulic system based on independent metering (IM) technologies, which can overcome the lost energy at the main control valve of the conventional electrohydraulic servo system. By scientifically arranging the proportional valves, the IM system can individually control the flow rate of the inlet and the outlet ports of the actuators. In addition, the IMV system can be used to effectively regenerate energy under different operating modes, thereby saving more energy than conventional hydraulic systems. Therefore, the IMV system has a great potential to improve the energy efficiency of hydraulic machinery. The overall IMV system, including the configuration, proportional valve, operation mode, and the control strategy is introduced via state-of-the-art hydraulic technologies. Finally, the challenges of IM systems are discussed to provide researchers with directions for future development.

• Journal of Electrical Engineering and Technology
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• v.11 no.6
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• pp.1628-1633
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• 2016

This paper derives an effective shape of the ferromagnetic pole pieces (low-speed rotor) for the reduction of transmission torque ripple in a magnetic-geared machine based on a Box-Behnken design (BBD). In particular, using a non-linear finite element method (FEM) based on 2-D numerical analysis, we conduct a numerical investigation and analysis between independent variables (selected by the BBD) and reaction variables. In addition, we derive a regression equation for reaction variables according to the independent variables by using multiple regression analysis and analysis of variance (ANOVA). We assess the validity of the optimized design by comparing characteristics of the optimized model derived from a response surface analysis and an initial model.

• The Journal of Fisheries Business Administration
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• v.35 no.2
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• pp.1-29
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• 2004

This paper aims to understand the points which the Board of Directors of the National Federation of Fisheries Cooperatives System has proposed, and to find some improvement. This Fisheries Cooperatives previously had a single board system operating two small board rooms which became independent within the two sectors of credit and .provision in addition to the existing board of directors. This is a very unique board of directors system which is not found in cooperatives in our country nor in the business world. This change of the board of directors of the Fisheries Cooperatives is ascribed to the reorganization of the system into a completely independent division system, which operates business separately based on each sector as opposed to the previous multiple cooperatives system. However, a plural board of directors system does contribute to the improvement of managerial efficiency by strengthening the self-control of each independent business section, but deepens conflicts between its internal organizations, and brings about a reverse function which might deteriorate both the controlling power of a systematic organization and the coordinating power between sectors. This paper made an analysis of acceptors' attitudes toward the board of directors of the fisheries cooperatives system by regulating all the staff directly related to the operation of the board of directors of the fisheries cooperatives system as a group of acceptors and by selecting one hundred and fifty persons among the staff as a sample. The inquiry into acceptors' attitudes was made using questionaries, and the data for this investigation was processed and analyzed using a statistical method. The contents of this paper are composed of I. an introduction, II. the findings of the questionary investigation, III. the overall opinion for the improvement of the board of directors system, and IV. a summary and conclusion.

• Honam Mathematical Journal
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• v.8 no.1
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• pp.21-49
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• 1986

A class of singular quadratic control problem is considered. The state is governed by a higher order system of ordinary linear differential equations and very general nonstandard boundary conditions. These conditions in many important cases reduce to standard boundary conditions and because of the conditions the usual controllability condition is not needed. In the special case where the coefficient matrix of the control variable in the cost functional is a time-independent singular matrix, the corresponding optimal control law as well as the optimal controller are computed. The method of investigation is based on the theory of least-squares solutions of multi-valued operator equations.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.11
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• pp.3398-3407
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• 1996

In this paper, we derive an algorithm and develope a computer program which analyze rapidly and precisely the inverse kinematics of robotic mechanism with spatial complex chain structure based on the relative coordinates. We represent the inverse kinematic problem as an optimization problem with the kinematic constraint equations. The inverse kinematic analysis algorithm, therefore, consists of two algorithms, the main, an optimization algorithm finding the motion of independent joints from that of an end-effector and the sub, a forward kinematic analysis algorithm computing the motion of dependent joints. We accomplish simulations for the investigation upon the accuracy and efficiency of the algorithm.

• Journal of the Korean Statistical Society
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• v.32 no.4
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• pp.425-448
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• 2003

Meta-analysis refers to quantitative methods for combining results from independent studies in order to draw overall conclusions. We consider hierarchical models including selection models under a skewed heavy tailed error distribution proposed originally by Chen et al. (1999) and Branco and Dey (2001). These rich classes of models combine the information of independent studies, allowing investigation of variability both between and within studies, and incorporate weight function. Here, the testing for the skewness parameter is discussed. The score test statistic for such a test can be shown to be expressed as the posterior expectations. Also, we consider the detail computational scheme under skewed normal and skewed Student-t distribution using MCMC method. Finally, we introduce one example from Johnson (1993)'s real data and apply our proposed methodology. We investigate sensitivity of our results under different skewed errors and under different prior distributions.

• Journal of the Korean Society for Precision Engineering
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• v.32 no.11
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• pp.937-944
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• 2015

Recently, the change of mechanical properties and microstructural evolution during severe plastic deformation (SPD), such as Equal Channel Angular Extrusion (ECAE), has been the subject of intensive investigation because of the unique physical and mechanical properties of severely deformed materials. In this study, two types of ECAE processes were considered, dies with intersection angles ${\Phi}$ of $90^{\circ}$ and $120^{\circ}$, using experiments and simulations. The decoupled method, in which the rigid-plastic finite element method is incorporated with the rate-independent crystal plasticity model, was applied to predict the texture evolution in commercially pure aluminum during the ECAE processes with $120^{\circ}$ and $90^{\circ}$ dies. The simulated textures were compared with a measured texture via an EBSD OIM analysis. The comparison showed that the simulated textures generally were in good agreement with the experimentally measured texture.

• Structural Engineering and Mechanics
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• v.66 no.4
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• pp.439-444
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• 2018

This paper presents a numerical study on the behavior of continuous hollow steel beam strengthened using carbon fiber reinforced polymers (CFRP). Most previous studies on the CFRP strengthening of steel beams have been carried out on the steel beams with simple boundary conditions. No independent study, to the researcher's knowledge, has studied on the CFRP strengthening of square hollow section (SHS) continuous steel beam. However, this study explored the effect of the use of adhesively bonded CFRP flexible sheets on the behavior of the continuous SHS steel beams. Finite Element Method (FEM) has been employed for modeling. Eleven specimens, ten of which were strengthened using CFRP sheets, were analyzed under different coverage length, the number of layers, and the location of CFRP composite. ANSYS software was used to analyze the SHS steel beams. The results showed that the coverage length, the number of layers, and the location of CFRP composite are effective in increasing the ultimate load capacity of the continuous SHS steel beams. Application of CFRP composite also caused the ductility increase some strengthened specimens.